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 OEE AND STONE MINING. 
 
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A TEXT-BOOK 
 
 OF 
 
 OEE AND STONE 
 MINING. 
 
 C. LE NEVE FOSTER, B.A., D.Sc., F.KS., 
 
 ASSOCIATE OF THE ROYAL SCHOOL OF MINES, ONE OF HER MAJESTY'S INSPECTORS 
 
 OF MINES, AND PROFESSOR OF MINING AT THE ROYAL COLLEGE OF 
 
 SCIEMCE, LONDON, WITH WHICH IS INCORPORATED 
 
 THE ROYAL SCHOOL OF MINES. 
 
 SECOND EDITION. 
 WITH FRONTISPIECE AND 716 ILLUSTRATIONS. 
 
 LONDON: 
 
 CHARLES GRIFFIN & COMPANY, LIMITED, 
 EXETEK STREET, STRAND. 
 
 1897. 
 
 [All rights renewed.] 
 
GIFT OF 
 
 OiAN FRANK it 
 
 MINING OEPT. 
 
 
 Printed hy BALLANTTNR, HANSON &> fa 
 At the Ballantyne Press 
 
PREFACE. 
 
 THE object of my text-book is to assist students in acquiring 
 a knowledge of the art of mining. Books and lectures are 
 not intended to take the place of practical teaching at mines, 
 but they render the training more thorough and complete 
 in many ways : they serve to explain the principles of the 
 art, to solve difficulties which perplex the beginner, to 
 suggest matters which he should observe, to tell him of 
 things beyond his ken, and to supply him with a system for 
 arranging his ideas methodically. 
 
 It will be seen by my numerous references that I have not 
 hesitated to avail myself of very varied sources of informa- 
 tion, and that I have taken care to avoid dwelling too much 
 upon English examples. 
 
 As far as possible I have set my face against the indis- 
 criminate use of the local slang of any particular district. 
 Mining is quite difficult enough without introducing unneces- 
 sary technical terms, and if words which are generally under- 
 stood by English-speaking nations will express our ideas 
 clearly, it is far better to employ them than to fall back upon 
 provincialisms which vary from one district to another; on 
 the other hand, certain expressions may sometimes recommend 
 themselves by reason of their pithiness, for adoption into our 
 tongue. 
 
 Within the limits of this preface it is impossible to name 
 
 M187C66 
 
vi PREFACE. 
 
 all the persons to whom I am indebted for matter contained 
 in this volume. Many useful facts have been picked up 
 while visiting mines at home and abroad, and in the course 
 of conversation with my colleagues. I therefore gladly 
 record my obligations to mining men generally, whom I 
 have invariably found ready to give me the benefit of their 
 experience. 
 
 I have to thank the Council of the Institution of Civil 
 Engineers, the Council of the Institution of Mechanical 
 Engineers, the Editors of Engineering and of the Engineering 
 and Mining Journal, M. Paulin Arrault, Mr. Augustus Bowie, 
 Mr. William Galloway, Messrs. Letcher and Michell, and 
 others, for permission to reproduce some of their figures. A 
 few of the blocks have been borrowed from Mr. Hughes' 
 Text-book of Coal Mining." 
 
 Mr. J. G. Lawn and Mr. L. H. Cooke have given me 
 Valuable assistance in correcting proofs, and the former espe- 
 cially has saved me from some of the pitfalls which beset the 
 path of an author who is passing a book through the press. 
 The very full index prepared for me by Mr. S. W. Price will 
 facilitate reference to my pages. 
 
 LLANDUDNO, NORTH WALES, 
 May, 1894. 
 
 ERRATUM. 
 
 Page 675, owing to an error in the original, the scale is incorrect, an 
 the readings should be multiplied by i^. 
 
GENERAL CONTENTS. 
 
 INTRODUCTION-. 
 
 CHAPTER I. MODE OF OCCURRENCE OF MINERALS. 
 
 PAGE 
 
 Classification ... 3 
 
 Gold ore . 
 
 PACK 
 
 . 41 
 
 Tabular Deposits . . 5 
 
 Graphite . 
 
 50 
 
 i. Beds ... 5 
 
 Gvpsum 
 
 5 
 
 2. Veins or Lodes . 5 
 
 Ice . . . . 
 
 
 Masses. .... 18 
 
 Iron ore . 
 
 Si 
 
 Examples ... 20 
 
 Lead ore . 
 
 55 
 
 
 Manganese ore . . 
 
 CJ 
 
 Amber ... 21 
 
 Mica .... 
 
 . 58 
 
 Antimony ... 21 
 
 Natural Gas 
 
 59 
 
 Arsenic . . . 21 
 
 Nitrafce of Soda . 
 
 . 62 
 
 Asbestos ... 21 
 
 Ozokerite . 
 
 6 3 
 
 Asphalt ... 22 
 
 Petroleum . 
 
 . 65 
 
 Barytes ... 23 
 
 Phosphate of Lime . 
 
 . 67 
 
 Borax . . 23 
 
 Potassium Salts 
 
 . 69 
 
 Boric Acid . . 25 
 
 Quicksilver ore . 
 
 7i 
 
 Carbonic Acid . . 25 
 
 Salt . . . . 
 
 75 
 
 Clay ..... 26 
 
 Siher ore 
 
 77 
 
 Cobalt ore . .. ,. 27 
 
 Slate . 
 
 79 
 
 Copper ore . . 28 
 
 
 8r 
 
 Diamonds . . . 37 
 
 Tin ore 
 
 3 
 
 
 Zinc ore . . 
 
 8<: 
 
 Freestone . . . .41 
 
 Faults . -.-. 
 
 j 
 . 87 
 
 CHAPTER II. PROSPECTING. 
 
 
 Chance Discoveries . 93 Sheading 
 
 105 
 
 Adventitious Finds . 95 
 
 Hut-hing 
 
 1 06 
 
 Geology as a Guide to Minerals 97 
 
 Piercing 
 
 106 
 
 Associated Minerals . 97 
 
 Lode Lights . 
 
 107 
 
 Surface Indications . 97 
 
 Altered Vege ( ation 
 
 107 
 
 Form of the ground 98 
 
 Old Workings 
 
 n8 
 
 Colour ... 99 
 
 Names of Places 
 
 IIO 
 
 Gozzan ... 99 
 
 Divining Rod 
 
 i ii 
 
 Indicative Plants . 103 
 
 Dipping Needle 
 
 in 
 
 Animals as Indicators ios 
 
 
 
CONTENTS. 
 
 CHAPTER XI. LIGHTING. 
 
 PAGE 
 
 Reflected Daylight . . .513 
 
 TAr.B 
 
 Wells Light . . . .516 
 
 Candles 513 
 
 Safety Lamps .... 
 
 5iS 
 
 
 Gas ...... 
 
 3 
 
 C22 
 
 
 Electric Lie-ht . 
 
 J^J 
 C23 
 
 CHAPTER XII DESCENT AND ASCENT. 
 
 j J 
 
 Steps and Slides . . .526 
 
 Buckets and Cages . 
 
 531 
 
 Ladders 527 
 
 Man Engine .... 
 
 5J4 
 
 CHAPTER XIII. DRESSING. 
 
 
 I. Mechanical Processes . 538 Buddies . 
 
 5^7 
 
 Washing . . 538 
 
 Motion in Air . 
 
 5S 9 
 
 Hand Picking . 541 
 
 Desiccation .... 
 
 592 
 
 Breaking Up . 542 
 
 Liquefaction and Distillation . 
 
 597 
 
 Agglomeration or Con- 
 
 Magnetic Attraction 
 
 600 
 
 solidation . . 565 
 
 III. Processes depending upon 
 
 
 Screening . . 566 
 
 Chemical Properties . 
 
 607 
 
 II. Processes depending upon 
 Physical Properties . 568 
 
 Solution, Evaporation, 
 and Crystallisation . 
 
 607 
 
 Motion in Water . . 568 
 
 Atmospheric Weather- 
 
 
 Simple Fall in Water . 570 
 
 ing 
 
 610 
 
 Upward Current Sepa- 
 
 Calcination or Roasting 
 
 611 
 
 rators . . -574 
 
 Cementation . 
 
 616 
 
 Separation by Water 
 
 Amalgamation 
 
 616 
 
 Flowing down 
 
 Application of Processes 
 
 620 
 
 Planes . . -579 
 
 Loss in Dressing 
 
 630 
 
 Plane Tables . 579 
 
 Sampling 
 
 632 
 
 Percussion Tables 584 
 
 Hand Sampling 
 
 632 
 
 Travelling Belts . 585 Machine Sampling 
 
 634 
 
 CHAPTER XIV. PRINCIPLES OF EMPLOYMENT OF MINING 
 LABOUR. 
 
 Payment by Time . . . 637 
 Measure or Weight 638 
 
 Payment by Combination of these 6 |i 
 Value of Product . 641 
 
 CHAPTER XV. LEGISLATION AFFECTING MINES AND QUARRIES. 
 
 Ownership .... 653 
 
 Taxation 655 
 
 Working Regulations . . 655 
 Metalliferous Mines Regula- 
 tion Acts .... 656 
 Coal Mines Regulation Act . 662 
 0>.her Statutes affecting Mines 662 
 Alkali Acts .... 665 
 Boiler Explosions Acts . . 666 
 Brine Pumping Act . . 666 
 
 Elementary Education Acts . 666 
 Enployers' Liability Act . 6)6 
 Explosives Act . . . 666 
 Factory and Workshop Acts 667 
 Quarry Fencing Act . . 667 
 Rivers Pollution Prevention 
 
 Act ..... 667 
 Stannaries Act . . . 668 
 Truck Acts . . . .668 
 
CONTENTS. 
 
 XI 
 
 CHAPTER XVI. CONDITION OF THE MINER. 
 
 Clothing 669 
 
 Hat 671 
 
 Boots 672 
 
 Jacket 673 
 
 Housing 673 
 
 Barracks .... 674 
 
 Cottages 
 Education 
 
 PAGE 
 . 677 
 . 682 
 . 683 
 
 Thrift 
 
 . 60O 
 
 Recreation 
 
 . . . 6 9 6 
 
 CHAPTER XVII. ACCIDENTS. 
 
 Death Rate of Miners from Ac- 
 cidents .... 698 
 Relative Accident Mortality Un- 
 derground and Aboveground 699 
 Classification of Accidents . 702 
 Underground . . . 704 
 Explosions of Fire Damp 
 or Coal Dust . . . 704 
 
 Falls of Ground 
 Shaft Accidents 
 Miscellaneous . 
 On the Surface 
 By Machinery 
 Boiler Explosions 
 Miscellaneous 
 Ambulance Training 
 
 704 
 
 711 
 711 
 711 
 711 
 712 
 
LIST OF ILLUSTRATIONS. 
 
 Frontispiece: Overhand Stoping, Cam Brea Tin Mine, Cornwall. 
 OCCURRENCE. 
 
 FIG. PAGB 
 
 1. Stratified deposits, section 5 
 
 2. Lead lode in slate, Wheal Mary Ann, Menheniot, Cornwall . 6 
 
 3. Tin lode in granite, West Wheal Basset, Cornwall ... 7 
 
 4. Section of lode, Canton mine, Otago, New Zealand ... 8 
 
 5. Diagram to show underlie 10 
 
 6. Measurement of underlie 10 
 
 7. General section of a lode 10 
 
 8. Longitudinal section of a lode showing ore-bodies . . .11 
 
 9. Intersection of veins 12 
 
 10. Section of vein with feeders * 12 
 
 11. Plan showing fahlbands, Kongsberg silver mines, Norway . . 12 
 
 12. Change of strike affecting richness of a lode .... 13 
 
 13. Richness or poverty of parallel parts of lodes : " Ore against ore " 17 
 
 14. Haematite deposit, Ulverston .... ... 19 
 
 15. Calamine deposit, Altenberg, Moresnet 19 
 
 16. Stockwork, Mulberry mine, near Bodmin, Cornwall ... 19 
 
 17. Borax Lake, California, plan 24 
 
 1 8. Cobalt ore, Skutterud, Norway 27 
 
 19. New Caledonia 28 
 
 20. Section across Man sf eld district 28 
 
 21. ,, of Eduard II. Shaft, Mansfeld 30 
 
 22. Geological map of Rio Tinto, Huelva, Spain . . . . 31 
 23) 
 
 ^ L Cross-sections of South Lode, Rio Tinto 32 
 
 20 J 
 2 
 
 III 
 
 Cross-sections of San Dionisio Lode, Rio Tinto .... 33 
 
 29. Map of Lake Superior copper district 35 
 
 30. De Beers mine, Kimberley, vertical section ... 3$" 
 
 31. Plan of diamond-bearing deposits, Kimberley ... 
 
 32. Section of strata at the flint mines, Brandon, Suffolk . 
 
 33. Salisbury mine, Johannesburg . . 
 
 34. M Sheba mine, Barberton ..... 
 35- auriferous alluvium, Caratal District, Venezuela. 
 36. showing auriferous "rainwash," Caratal . . 
 
 38 
 40 
 42 
 33 
 44 
 45 
 
 Saddle-reefs, Bendigo . . ...... 46,47 
 
xiv LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 39. Mount Morgan mine, Queensland, section to illustrate geyser 
 
 theory ...... 48 
 
 40. view of deposit ..... 49 
 
 41. sections based en late developments ... 50 
 
 42. Gypsum mine, Nottinghamshire ....... 51 
 
 43. Sections of ironstone bed, Cleveland ...... 52 
 
 44. Chapin Iron mine, Lake Superior, section ..... 54 
 
 45. Lead-bearing sandstone, Mechernich, general section . . 55 
 
 46. Evening Star mine, Leadville, Colorado, section . . . .56 
 
 47. Manganese ore bed, near Barmouth, North Wales ... 58 
 
 48. Natural gas ; section through Findlay, Ohio .... 60 
 
 49. Nickel deposit, New Caledonia . . . . . . .60 
 
 bearing veins, New Caledonia ...... 61 
 
 50) 
 5i) 
 
 deposit, Sudbury, Canada ..... 61,62 
 
 54. Nitrate of soda, Chili ....... . .62 
 
 55. Ozokerite at Boryslaw, Galicia, plan ...... 63 
 
 56. section ..... 64 
 
 57. filling fissures, Boryslaw . . . . . .64 
 
 58. Baku oil region, section ...... . -65 
 
 59. Spouting oil well, Baku ........ 66 
 
 60. Deposit of phosphate of lime, Beauval, France .... 68 
 6 1. Bed of phosphatic nodules, South Carolina ..... 68 
 
 62. Potassium salts and rock salt, Stassfurt ..... 70 
 
 63. Quicksilver-bearing sandstone, section, Ekaterinoslav, Southern 
 
 Kussia ...... ..... 72 
 
 64. Cross section of quicksilver deposit, Great Western mine, California 73 
 
 65. Longitudinal section ,, -74 
 
 66. Cross section of Eureka mine, Nevada ..... 77 
 
 67. slate beds, Festiniog, N. Wales .... 80 
 
 68. the Oakeley Quarries, Festiniog . . . .81 
 
 69. Sulphur bank, Iceland ........ 82 
 
 70. seam, near Caltagirone, Sicily ..... 82 
 
 7*1 Cross sections of tin veins, St. Agnes, Cornwall .... 84 
 
 73. Map of part of Vegetable Creek, New South Wales ... 85 
 
 74. Cross section showing " deep-leads " of tin ore, Vegetable Creek 86 
 
 75. Wash-out fault .......... 87 
 
 76. Ordinary fault .... ...... 88 
 
 77. Step fault ........... 88 
 
 78. Fault with zone of broken rock ....... 88 
 
 79. Measurement of throw of a fault ...... 89 
 
 80. Section of fault indicating amount of throw .... 89 
 
 g* } Variation of throw along the strike of a fault .... 90 
 
 83. Reversed fault showing bending of strata ..... 90 
 
 84. .......... .90 
 
 85. Plan showing heave of vein sideways ...... 91 
 
 86. Illustration of heave sideways produced by a sliding along dip of 
 
 fault . . ...... " . . .91 
 
 87. Schmidt and Zirnmermann's rule ...... 92 
 
 88. Succession of faults, Penhalls mine ..... .92 
 
 PROSPECTING. 
 
 89 Section of mineral vein showing projecting outcrop of a hard 
 
 vein ...... - ...... 98 
 
LIST OF ILLUSTRATIONS. xv 
 
 FIG. 
 
 90. Cross-section of lode with gozzan . . . . . . 101 
 
 91. Longitudinal section showing relation of the gozzan to natural 
 
 drainage level .......... 101 
 
 92. Use of the divining rod ........ 1 1 1 
 
 93. Dipping needle used in searching for iron ore . . . .112 
 
 BORFNG. 
 
 94. Earth anger cr gouge ......... 114 
 
 95. Derrick for lifting rods . . .. .. . , . 114 
 
 96. ,, &c., for boring by rotation . . , . . .115 
 
 97. Screwed coupling for hollow boring rods ..... 116 
 
 98. Rotating and guiding arrangements and loose connection . . 117 
 
 99. Boring bit with two sets of cutters . . . . . . 117 
 
 100. Cutting out a core with diamond drill . , . . .118 
 
 101. Plan of large crown for diamond drill , . . . .118 
 
 102. Arrangement of core tube and sediment tube . . . .119 
 
 103. Core-extractor ..... , , , . .119 
 
 104. Dauntless diamond drill . . . , , . . .120 
 
 105. Little Champion diamond drill ....... 123 
 
 106. Small diamond drill for prospecting ...... ' 123 
 
 107. Chisel bit ........... 125 
 
 108. Screw-joint for boiing-rods ..... . . 125 
 
 109. with connecting socket . . .125 
 no. L'f ting hook or dog ....... . 125 
 
 in. Retaining key .......... 125 
 
 112. Cap, or lifting rin# and socket ....... 125 
 
 113. Portable plant for boring with rods ...... 126 
 
 114. Set of tools for use with above ....... 127 
 
 115. Shell-pump or sludger . v ^ 128 
 
 ' Oeynhausen's sliding joint ... ..... 129 
 
 ;jS j Free-falling tool . ......... 129 
 
 1 20. Arrault's free-falling tool used with bumping piece . . .130 
 
 121. Enlarged view of catch for free-falling tool . . . ,130 
 
 122. Kind's free-falling tool ........ 130 
 
 123. Crow's-foot .... ....... 131 
 
 124. Bell-screw ........... 131 
 
 125. Riveted lining tube with screwed joints ..... 131 
 I2t>. Lining tube with flush screwed joint ..... 131 
 
 128 I Kotatin S t001 for cutting out a core ...... 132 
 
 129. Core extractor ....... ... 132 
 
 1 3 A j Compass-case for marking core ...... 133 
 
 131. Wooden boring rod used in Galicia ...... 134 
 
 132. Rig for boring by the Canadian system ..... 135 
 
 133. American rig^for boring a well ....... 138 
 
 134. Rope-socket . . . . ....... 139 
 
 135. Sinker-bar ........... 139 
 
 136. Jars . . . . . . . . . . 139 
 
 137. Auger-stem ........... 139 
 
 :g} Bit ............ >39 
 
 140. Temper screw ...... .. 140 
 
 141. Sand-pump . ..... , . . . . 140 
 
 142. Method of working maid for drive-pipe ..... 140 
 
xvi LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 143. Boring plant, Mather and Platt's system ..... 143 
 
 144. Enlarged view of Mather and Platt's cylinder and pulley . . 144 
 
 145. Mather and Platt, boring head and turning device . . .146 
 
 146. Kecording phial for Macgeorge's clinograph . . . ,147 
 
 *47 I Survey of bore-hole, Scotchman's United mine, Victoria . .149 
 
 BREAKING GROUND. 
 
 149. Poll-pick ........... 152 
 
 150. Double-pointed pick ......... 152 
 
 151. Pick used for cutting j<id, Bath stone quarries .... 152 
 
 152. with movable blade, Mansfeld . . . , . .152 
 
 153. Acme pick ........... 153 
 
 154. Universal pick .......... 153 
 
 155. Cornish gad .......... 154 
 
 156. Saw for cutting freestone ........ 154 
 
 157. Elliott drill . . . . ...... 155 
 
 158. Ratchet drill .......... 155 
 
 159. Jumper used at Mechernich ....... 156 
 
 1 60. ,, in Northamptonshire ...... 156 
 
 161. in Festiniog slate mines ..... 156 
 
 162. in Cleveland iron mines ...... 156 
 
 163. Borer or drill . . ........ 156 
 
 g Cutting edge of drill, Minera, North Wales . . . .158 
 
 1 66. Bore-hole with triangular section . . . . .159 
 167. Hammer for single-handed boring, Festiniog .... 159 
 1 68. Cornish mallet, or double-handed boring hammer . . .160 
 
 169. Tamping bar .......... 160 
 
 170. Needle, or pricker ...... . . .161 
 
 171. Charging spoon and scraper ....... 161 
 
 172. Claying bar . . ........ 161 
 
 Knox system of boring rending holes . . . . . .162 
 
 Reamer, or broach for enlarging holes by the Knox system . 162 
 176. Hanarte air-compressor 16' 
 
 175. Reamer, or broach for enlarging holes by the Knox system . 162 
 
 176. Hanarte air-compressor 165 
 
 177. Dubois and Francois air compressor 166 
 
 178. Ingersoll- Sergeant air-compressor 167 
 
 179. Valve of Ingersoll-Sergeant air- compressor .... 168 
 
 1 80. Arrangement of steam and air cylinders 168 
 
 181. Underground reservoir for compressed air, Mansfeld . .169 
 
 182. Joint for compressed air main, Blanzy 170 
 
 | g3 [ Mode of fixing air main in shaft 170 
 
 185. Eadie and Sons' joint for lap-welded pipe 170 
 
 1 86. Dunbar and Ruston's steam navvy 174 
 
 187. Kincaid and McQueen's bucket dredge 176 
 
 1 88. Priestman's grab dredger 177 
 
 189. Steavenson's twist drill on carriage, worked by electric motor . 179 
 
 190. petroleum engine 180 
 191 
 
 J^ -Bits used with machine drills 181 
 
 I94/ 
 
 195. Shaped bars of steel for cross-bits 182 
 
 196. Barrow drill 183 
 
 197. Drill mounted on stretcher bar 184 
 
LIST OF ILLUSTRATIONS. xvii 
 
 FIG. 
 
 198. Climax drill 185 
 
 1 99 1 Bosseyeuse, or boring ram of Dubois and Francois . . . 186 
 
 201. Ingersoll-Sergeant Eclipse drill 188 
 
 202 I Socket for holding the tool 189 
 
 204. Franke drill 190 
 
 205. Use of Franke drill and undercutting chisel, Mansfeld copper 
 
 mines 191 
 
 206. Hirnant drill 192 
 
 207. Sergeant drill 193 
 
 208. turning mechanism 194 
 
 209. Adelaide drill 195 
 
 210. Darlington drill, longitudinal section 196 
 
 211. side elevation 196 
 
 212. ,, mounted on stretcher-bar . . . .197 
 
 213. Marvin electric drill, working parts 198 
 
 214. Franke's mechanical chisel 200 
 
 215. Gillott and Copley's undercutting machine . .... 203 
 
 216. Walker's circular saw 204 
 
 217. Wire saw 205 
 
 218. Stanley's tunnelling machine, side elevation .... 207 
 
 219. Elliott multiple wedge, longitudinal and cross sections . . 208 
 
 221 
 
 22 }- Strength of explosives as shown by Trauzl's lead block test . 216 
 224^ 
 
 226. Detonator, Nobel's, treble strength 218 
 
 227. quintuple strength 218 
 
 228. Firing a charged hole 219 
 
 229. Rifting hole with air-spare above charge, Knox system . .219 
 
 230. Simultaneous fuse of Bickford, Smith & Co. .... 219 
 
 231. Brain's high-tension electric fuse 220 
 
 232. Nobel's 221 
 
 233. low-tension 221 
 
 234. Planning holes for driving a level by hand 222 
 
 235. Section of lode with gouge or selvage 222 
 
 236. Arrangement of holes for driving a level with a machine drill 
 
 (elevation) 223 
 
 237. Arrangement of holes for driving a level with a machine drill 
 
 (longitudinal section) 223 
 
 238. Halkyn drainage tunnel, arrangement of holes for driving . 223 
 
 239. Driving level with Ferroux drill and bosseyeuse, Bex, Switzerland 224 
 
 240. Arrangement of holes for sinking a shaft, Foxdale, plan . . 225 
 241- section . 225 
 
 SUPPORTING EXCAVATIONS. 
 
 242. Level with cap or bar supporting roof ..... 232 
 
 243- i. and leg 232 
 
 24C I ^^ n ^ s between cap and leg 232 
 
 246. Timber frame and lagging for level 232 
 
 247. Horned set for level in loose ground 233 
 
 248. Timber frame and lagging for heavy ground, Comstock lode . 233 
 249- Timbering for level, Rio Tinto mines 233 
 
xviii LIST OF ILLUSTKATIONS. 
 
 FIG. PAGE 
 
 250. Pigsty timbering for wide level, cross-section .... 234 
 
 251. section along Hue of strike . 235 
 
 252. Spilling in loose ground, longitudinal section .... 236 
 
 253. ,, cross section 236 
 
 254. Plank lining for shaft, plan 237 
 
 255. Shaft frame or set 237 
 
 256. ,, enlarged view of joint 237 
 
 257. Plan of timbering for shaft, Comstock lode .... 238 
 
 258. Section through dividing ,, ,, .... 238 
 
 259. End view of timbering for shaft ,, .... 238 
 
 260. Plan of timbering for shaft, Calumet and Hecla mine . . 239 
 
 261. Shaft timbering, Clausthal, plan 240 
 
 262. end view 241 
 
 263. Timbering chamber for water-wheel, Clausthal . . . .241 
 
 264. Plan of shatt frame for spilling 242 
 
 265. Sinking sbaft by spilling, vertical section 243 
 
 266. Prop supporting roof of bed . 244 
 
 267. Chocks supporting roof 245 
 
 268. Large chocks, Wieliczka salt mines 245 
 
 269. Pigsty timbering in stopes, Day Dawn mine, Queensland . . 245 
 
 270. Square set, Comstock lode, Nevada, elevation .... 246 
 
 271. plan 246 
 
 272. application in overhand stopes 246 
 
 273. Richmond mine, Nevada 247 
 
 274. timbering in overhand stopes, Broken Hill mines, 
 
 sectional elevation 248 
 
 275. timbering in overhand stopes, Broken Hill mines, 
 
 horizontal section 248 
 
 276. Joint for square set, Broken Hill mines 249 
 
 277. Square sets supporting hanging wall 249 
 
 278. Strengthening square sets 249 
 
 279. Dry walling for level, Forest of Dean 250 
 
 280. Lex el lined with masonry, Clausthal ...... 250 
 
 281. Level with arch of masonry 251 
 
 282. at side 251 
 
 283. Lining shaft with brickwork 252 
 
 284. Shaft lined with concrete, Foxdale mine 253 
 
 285. Stone pillar supporting roof 254 
 
 286. Halkyn drainage tunnel, section showing iron supports . . 255 
 
 287. cast-iron prop and chair . . . 255 
 
 288. ,, section of iron rail used . . . 256 
 
 289. Section of steel beam, Nunnery Colliery, Sheffield . . . 256 
 
 290. Steel beam on timber legs 257 
 
 291. Rolled steel caps and legs forming frame for level . . . 258 
 
 Section and plan of steel plate used 258 
 
 294. Level lined with curved iron rails, Hartz 258 
 
 295. Bent steel bar for supporting roof of level 259 
 
 296. Steel frame in two parts for lining level, Anzin .... 259 
 
 297. Cross section showirg joint 260 
 
 298. Steel frame in three pieces, Anzin 260 
 
 299. Circular frame for level, channel steel 261 
 
 300. Section through joint of the frame 261 
 
 301. Circular frame for level, bulb-tee steel 262 
 
 302. Section through joint of the frame 262 
 
 303. Iron ring in two parts for supporting shaft lining . . . 263 
 304.. Shaft lining, ozokerite mines, Boryslaw '. . 264 
 
 305. King of channel iron for shaft 264 
 
 306. Section through joint of ring 265 
 
LIST OF ILLUSTRATIONS. xix 
 
 FIG. 
 
 307. Prop of I-steel, and plan of end 266 
 
 308. Solid wooden tubbing for shaft, plan 266 
 
 309. Sections of cast-iron wedging cribs 267 
 
 310. Section through coffering 268 
 
 311. Segment of cast-iron tubbing 269 
 
 312 1 Cast-iron tubbing resting on curb 270 
 
 314. Small composite borer or trepan, Kind-Chaudron system . . 272 
 
 315. Large composite borer ,, . . 273 
 
 316. Section of tubbing with moss-box ,, ,, 274 
 
 317. ., ,, compressed, and false tubbing 274 
 
 318. Enlarged section of the three wedging curbs .... 274 
 
 319. Section of tubbing at Lievin 276 
 
 320. Sinking by freezing proces-s in watery strata, Siberia . . . 279 
 
 321. . . . 280 
 
 322. Poetsch's freezing process, section of freezing tube . . . 282 
 
 323. vertical section of thafc . . . 282 
 
 EXPLOITATION. 
 
 324. Open workings for iron ore, Northamptonshire .... 287 
 
 325. ,, plan showing arrangement of workings . . 288 
 
 326. Section of terraces, Penrhyn slate quarry 288 
 
 327. View of opencast, Rio Tinto mines 289 
 
 328. Section of Mulberry mine near Bodmin, Cornwall . . . 289 
 
 329. Section showing effect of a large bJas , Messdna . . . 290 
 
 33 I Details of the tunnel for large blast ,, .... 291 
 
 332. China clay workings, Hensbarrow, Cornwall .... 292 
 
 333. End view of flume and trestle 294 
 
 334. View of flume carried across a valley 294 
 
 335. ,, by iron brackets on side of canon . . 295 
 
 336. Riveted wrought-iron water pipe 295 
 
 338 I Pressure box or "bulkhead" 296 
 
 339) 
 
 340. Monitor 296 
 
 341. Hydraulic mining, attacking the gravel bank .... 297 
 342 
 
 343 y Sluice box . 298 
 
 344 
 345 
 
 34 Hydraulic elevator ......... 300 
 
 348 
 
 349. at the Blue Spur, Otago, New Zealand . . 301 
 
 350. Working salt by bore-hole, Middlesbrough 305 
 
 351. Plan of bore-holes, Middlesbrough .... 306 
 
 352. Section of underground gypsum quarries, Paris . 
 
 353. Plan . . 
 
 354. Underground workings for stone, near Bath, plan 
 
 355- >, vertical sect 
 
 356. ,, plan . 
 
 357. Plan showing pillars, Marston Hall salt mine, Northwioh 
 
 358. Vertical section ,, 
 
 359. Underground workings for slate, Festiniog, plan 
 
 360. ,, cross-section 
 
 on 
 
 309 
 309 
 310 
 310 
 310 
 
 313 
 
 313 
 
 French Ardennes, cross-section 313 
 
xx LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 362. Working ironstone, Cleveland, plan 316 
 
 363. Kestronguet tin stream works, plan 317 
 
 364- ,. i< > section 317 
 
 365. Cross-section of the Ked Point and Damm channels, California . 319 
 
 366. Plan of longwall workings, Mansfeld copper mine . . . 324 
 
 367. Transverse section of an ore mine, lode worked by vertical shaft 326 
 
 368. Longitudinal ,, 326 
 
 3^9 I Underhand stoping, original method . . . . . 327 
 
 371. on sides of winze ..... 327 
 
 372. Longitudinal section of Dolcoath mine, Cornwall . . 328 
 
 373. Transverse section ... 329 
 
 374. Oveihand stoping, with rubbish stowed on stulls . . . 329 
 
 375. cross-section 330 
 
 376. excavation left open 330 
 
 377. on a narrow lode, cross-section . . . 330 
 
 378. Working a wide lode with filling up, Van mine .... 331 
 
 379. Wide lode woi ked by cross-cutting, transverse section . . 334 
 3 8 o- > i P la n 334 
 
 381. worked in slices, parallel to the dip .... 335 
 
 382. worked in horizontal slices, with filling up, Fox dale 
 
 Mine 336 
 
 38 I Working a wide lode having a hard and a soft part . . 337 
 
 385. Rio Tinto, pillar and chamber workings, vertical section . . 339 
 
 386. plan of preliminary 
 
 drivagps . . 339 
 
 387. plan of completed 
 
 chambers . . 339 
 
 388. Working "churns," Forest of Dean 340 
 
 389. Plan of De Beers Mine, new system of working .... 341 
 
 390. of drivages and chambers 342 
 
 391. Vertical section of drivages and chambers 342 
 
 392. Haematite deposit, North Lancashire, cross-section . . . 342 
 
 393. plan of main levels and crosscuts . . . 343 
 
 394. plan of workings 344 
 
 395. ,, section of working 345 
 
 396. Working zinc ere, Diepenlinchen mine 346 
 
 HAULAGE. 
 
 Bisections of rails 351 
 
 399. Steel sleeper, Legrand's 352 
 
 400. ,, Howard's 352 
 
 401. ,, made from biidge rail 353 
 
 4om) 
 
 402 > Clip used with above 353 
 
 402J 
 
 403. Sleeper made of channel-iron 353 
 
 404. flat bar-iron 35 3 
 
 405. Cast-iron turnplate 354 
 
 406. Turnplate with iron bar guides 354 
 
 407. Mine waggon, Van mine 355 
 
 ^ I Mine waggon, with sheet-iron body and bent sides . . . 356 
 
 410) ,, oval body and automatic lubrication, 
 
 41 if Saint-Etienne . 359 
 
LIST OF ILLUSTRATIONS. xxi 
 
 Steel waggon, Llanbradach colliery ...... 359 
 
 414. Self -oiling pedestal ......... 361 
 
 415. Diagram, main and tail rope system ...... 366 
 
 416 
 
 Rice's clutch 369 
 
 4 1 ! 
 418) 
 
 419 / ^Endless rope system, plans of sidings 370 
 
 420] 
 
 421. double track 371 
 
 422. Drums and air-brake of self-acting incline, Bilbao . . . 377 
 
 423. Aerial ropeway, Otto's system, view of tub . . . . 382 
 
 *2*J iron standard . . . .383 
 
 426. ,, clip, side view .... 384 
 
 427. ,, cross-section of clip . . . 384 
 
 428. ,, plan of clip .... 384 
 
 429. ,, Sheba Gold Mining Company, 
 
 Barberton 384 
 
 430. Gottessegen Colliery, Upper Silesia . . . 385 
 
 HOISTING. 
 
 431. Turbine and connections for winding, Great West Van mine . 390 
 4 ^ I Compound winding engine, Llanbradach Colliery . . .391 
 
 434. Drum with reserve length of rope 392 
 
 435- , v section 392 
 
 436. Reel for flat rope, elevation . 394 
 
 437- P^n 394 
 
 438. Wooden pulley-frame, side elevation 395 
 
 439- front 395 
 
 440- plan 395 
 
 441. Wrought-iron head-gear, " Ruck Shaft," De Beers mine . . 396 
 
 442. " Incline Shaft " . 397 
 
 443. Winding pulley . . . . 398 
 
 443. Wire rope with hemp core 399 
 
 44;! " " ordinar y new and when worn 400 
 
 44^1 Lang's lay 400 
 
 * [ Latch and Batchelor's " flattened strand " . . 400 
 
 44 J ) 
 
 45- > outside view . . . 400 
 
 451. ,, f Elliot's " locked coil " 401 
 
 452. Spring hook for attaching rope to bucket, &c 4.02 
 
 453. Capping wire ropes, eye spliced on 402 
 
 454. eye made with screwed clamps . . . 402 
 455- i) >, section . 402 
 
 456. ,, socket riveted on 402 
 
 457) 
 
 458^ ,, ,, for locked coil rope, outside view and sections 403 
 459J 
 
 ^ 6l J improved form of clamped capping . . 403 
 
 462. Wrought-iron kibble ,, . 404 
 
 463. Aerial incline, " Blondin," used at granite quarries, near Aber- 
 
 deen 407 
 
xxii LIST OF ILLUSTKATIONS. 
 
 FIG. PAGR 
 
 464. Galloway's improved wire rope guides for bucket . . . 408 
 
 465. walling stage, elevation 409 
 
 466. plan of lower floor . . . 409 
 
 467. Filling skip in shaft 
 
 468. Self -discharging skip, De Beers mine, plan 
 
 469. ,, side elevation . 
 
 470. Improved shoot with double doors, De Beers mine 
 
 Self -discharging skip, Frongoch mine 417 
 
 . 411 
 
 . 412 
 
 . 412 
 
 . 473 
 
 471. Automatic dumping arrangement for inclines, side elevation . 413 
 
 472. >, it plan . . . 413 
 
 473. perpendicular " Kock " shaft, 
 
 De Beers mine, side eleva- 
 tion 414 
 
 474. front eleva- 
 
 tion of a part . . .415 
 
 475. Ormerod's detaching link 416 
 
 476 
 
 477 
 478 
 479 
 480) 
 
 481. Cage, Comstock lode, front elevation . . . . . .418 
 
 482. ,, side elevation 418 
 
 483) 
 
 484 \ Haniel & Lueg's keps for cage 420 
 
 4B<) 
 
 ^Q [ Detaching hooks, King & Humble's 422 
 
 47 ) 
 
 489} Walker ' s -423 
 
 490- ,. i open. . . . . . . 424. 
 
 DRAINAGE. 
 491. Wooden dam in level, plan . ....... 430 
 
 Spherical wooden dam ......... 431 
 
 494) 
 
 495f " " ........ 432 
 
 496. Brick dam in shaft, vertical section ...... 433 
 
 497 I Galloway's pneumatic water tank, vertical section . . . 438 
 
 499. automatic water tank, side view .... 439 
 
 500. ,, front view .... 440 
 
 Bowden's automatic tanks for use on slopes . . . .441 
 
 503. dumping at head of slope . .441 
 
 504. Compound double-acting pumping engine, Mansfeld . . . 444 
 
 505. Strapping-plates for wooden pump rod ..... 445 
 
 506. V-bob, side elevation ......... 446 
 
 507. plan .......... 446 
 
 508. Fend-off bob, side elevation ....... 446 
 
 509. Running loop, side view . ....... 447 
 
 510. ,, front view ........ 447 
 
 511. West & Darlington's hydraulic plungers lor working inclined 
 
 rods ........... 447 
 
 512. Drawing lift in shaft, vertical section ...... 449 
 
 -P ump bucket for single valve ....... 449 
 
LIST OF ILLUSTRATIONS. 
 
 xxni 
 
 FIG. 
 
 515. 
 516. 
 517. 
 518. 
 519. 
 520) 
 521) 
 522. 
 
 5 23 1 
 5 2 4) 
 
 55 . 
 
 Half-moon ........... 449 
 
 Form for two valves attached at circumference .... 449 
 
 in the middle .... 449 
 
 Shape of leather band for packing pump bucket . . . 449 
 
 Lifting pump used on the Comstock lode ...... 451 
 
 Rising main, joint and mode of supporting column in shaft, Com- 
 
 stock lode .......... 451 
 
 Plunger pump in shaft, vertical section ..... 451 
 
 Hake's mouth valve ....... 
 
 Butterfly valve 
 Trelease's valve 
 
 453 
 453 
 453 
 
 530 h Teague's noiseless valve, vertical section, side view and plan . 454 
 
 53 1 ) 
 
 532. Double-beat valve fixed in place, vertical section . . . 454 
 
 533- open 454 
 
 534. ,, ,, elevation of valve and lower seat . . 454 
 
 535. Rittinger pump, elevation 456 
 
 536. ,, vertical section . 456 
 
 537. Balance bob 457 
 
 538. West and Darlington's hydraulic counterbalance . . . 458 
 539- ,, for inclined rods 458 
 
 540. Bochkoltz regenerator 459 
 
 541. Rossigneux's system of counterbalancing 460 
 
 542. plan . . . .460 
 
 543. Catches 461 
 
 544. Pumping engine, Shakemantle Mine, side view .... 462 
 545- ,i i front view . . .463 
 546. Pumps fixed in shaft , side view .... 464 
 547- M t> ii front view . . . 464 
 
 548. Pumps in shaft, bottom lift, Shakemantle Mine, side view . 465 
 
 549. Plan of shaft , . 465 
 
 550. Pumps in shaft, bottom lift , ,, front view . 465 
 
 551. Underground pumping engine, Mansfield 468 
 
 552- plan .... 468 
 
 553. Pulsometer, vertical section 469 
 
 554. Moore's hydraulic pump 470 
 
 555. Pohle pump 471 
 
 556. Pump worked by compressed air, Evans and Yeitch . . . 472 
 557- * > i, cylinders for working valves . 472 
 
 VENTILATION. 
 
 558. Natural ventilation by two shafts joined by a level . . . 483 
 
 559- ., by adit and shaft 483 
 
 560. by two shafts joined by an incline . . 483 
 
 561. of end of level 485 
 
 562. bad 485 
 
 563- of a single vertical shaft . . . . 486 
 
 564- of an incline 486 
 
 S^S- > of a rise . . . . . . 486 
 
 5 66 - , of end of level by an air-sollar . . . 487 
 
 567* , i, longitudinal 
 
 section . 487 
 " 68 ' > i> > M 4^7 
 
xxiv LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 569. Natural ventilation of shaft by an air pipe 488 
 
 570. Method of ventilating a rise 488 
 
 571. lower levels 489 
 
 572. by winzes 489 
 
 573. Ventilating furnace, vertical section 491 
 
 574- . P lan 49i 
 
 575. ,, front elevation ...... 491 
 
 576. Williams' water-jet apparatus 492 
 
 577. Teague's aspirator , 493 
 
 578. Hartz blower, elevation , 494 
 
 579- *> >. section . . .494 
 
 580. Roots' blower, cross section 494 
 
 581. Capell fan, vertical section 495 
 
 582. cross section 495 
 
 583. Guibal fan, vertical section 496 
 
 584. Schiele fan 497 
 
 585. Waddle fan 497 
 
 586. Lunge's apparatus for testing the air of mines .... 504 
 
 587. valve-tube, vertical section .... 504 
 
 588. Water-gauge, model to illustrate action of .... 508 
 
 589. Murgue's graphic representation of the influence of the sides 
 
 of airways upon the amount of friction . . . . 511 
 
 LIGHTING. 
 
 590. Candle holder, United States 514 
 
 591. ,, ("Spider "), Australia 515 
 
 592. Lamp for burning oil, Scotland 516 
 
 593. Wells light . 517 
 
 594. Davy lamp 519 
 
 595. Clanny lamp 519 
 
 596. Mueseler lamp 520 
 
 597. Marsaut lamp 521 
 
 598. Ashworth's Hepplewhite-Gray lamp 522 
 
 599. Sussmann electric lamp 523 
 
 DESCENT AND ASCENT. 
 
 600. Iron ladder 529 
 
 601. Section showing manner of joining two ladders .... 529 
 
 602. Arrangement of ladders in shaft 530 
 
 g 3 I Double-rod man-engine . . . . . . . 534 
 
 605. Single-rod man-engine . 534 
 
 DRESSING. 
 
 606. Rotary diamond washing machine 540 
 
 607. Revolving drum for washing smalls before picking . . . 541 
 
 608. Scraper 542 
 
 609. Ragging . 543 
 
 610. Spalling 544 
 
 6 1 1. Cobbing 544 
 
 612. Bucking 545 
 
 613. Thin wedge for splitting slate, North Wales .... 545 
 
 614. Blake's rock-breaker, section 547 
 
LIST OF ILLUSTRATIONS. 
 
 XXV 
 
 FIG. PAGE 
 
 615. Dodge crusher 548 
 
 616. lo-stamp battery with wooden frame 549 
 
 617. Single discharge mortar 549 
 
 618. Tappet . . .549 
 
 619. Cam 549 
 
 620. Stamp head, shoe, and die 549 
 
 621. Steel shoe and die before and after wear 550 
 
 622. Ball's steam-hammer stamp 552 
 
 623. Leavitt's differential steam-cylinder . . . 553 
 
 624. Cornish crushing rolls 554 
 
 625. Rolls, cross section 554 
 
 626. Krom's roll, section 555 
 
 627. Krom's crushing rolls, side elevation . . . 555 
 
 628. Edge-runner 557 
 
 629. Ball pulveriser, Krupp-Grusonwerk, cross-section 558 
 
 630. ,, ,, longitudinal section 558 
 
 631. Carr's disintegrator, section 559 
 
 632. Gates crusher 560 
 
 633. Huntington mill, plan .561 
 
 634. sectional elevation 562 
 
 635. Paxman's improved roller and yoke, section .... 562 
 
 636. plan 562 
 
 637- i> 563 
 
 638. Sawing machine for slate 564 
 
 639. Greaves' circular slate-dressing machine . . 565 
 
 640. Perforated sheet-metal, with round holes, imm. 567 
 
 641. 2mm. 
 
 642. 5mm. 
 
 64205. Trommel for making four classes . . . 567 
 
 643. Experiment to show separation of minerals by free fall in water 569 
 
 6 4 ^ I Tossing and packing in keeve 571 
 
 646. Experimental jigging-sieve 571 
 
 647. jigger 572 
 
 648. Two-compartment jigger, front sectional elevation . . . 573 
 
 649. ,, cross- section 573 
 
 650. Experimental jigger with fixed sieve 573 
 
 651. Jigger with piston moving horizontally, Frongoch mine, cross- 
 
 section 574 
 
 652. Jigger with piston moving horizontally, longitudinal cross- 
 
 section 574 
 
 653. Pyramidal separator, Jacomety and Lenicque, sec 'ion 575 
 
 654. plan . 575 
 
 655. Upward current separator, Frongoch mine, section . 576 
 
 656. plan . 576 
 
 657. Osterspey's siphon separator, vertical section . . 578 
 
 658. longitudinal section of front 
 
 chamber 578 
 
 659. ,, plan 578 
 
 660. Cornish self-acting double frame, plan 580 
 
 66 2 [ >, , sectional elevation . . . 580 
 
 663. Linkenbach table, sectional elevation 582 
 
 664. plan 582 
 
 665. Revolving round table, Jacome'ty and Lenicque .... 584 
 
 666. ,, plan . . .584 
 
 667. Rittinger's side-blow percussion table, plan .... 585 
 
 668. Frue vanner, diagrammatic longitudinal section . . . 585 
 
 669. Stein's endless belt, side elevation 587 
 
 C" 
 
xxvi LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 670. Stein's endless belt, plan 587 
 
 671. end elevation 587 
 
 672. Convex round buddle, sectional elevation 588 
 
 673- P lan 588 
 
 674. Experimental pneumatic jigger 590 
 
 675. Clarkson-Stanfield concentrator 591 
 
 676. Tanks and drying floors for china clay, plan and a cross-section. 593 
 
 677. Kiln for drying fuller's earth, section 595 
 
 678. Ruelle's revolving drier, longitudinal section .... 596 
 
 679. Large kiln, Sicilian sulphur mines, vertical section . . . 599 
 
 680. plan 599 
 
 68 1. Chase magnetic separator, longitudinal section (diagrammatic) . 60 1 
 
 682. Conkling magnetic separator 60 1 
 
 683. Hoffmann magnetic separator 602 
 
 684. Kessler magnetic separator 603 
 
 685. Lovett-Finney magnetic separator 603 
 
 686. Ball-Norton magnetic separator 603 
 
 687. Buchanan magnetic separator 604 
 
 688. Friederichssegen magnetic separator, longitudinal section . . 605 
 
 689. ,, plan 605 
 
 690. Wenstrb'm magnetic separator 605 
 
 691. Edison's magnetic separator 4 606 
 
 692. Brunton's calciner, sectional elevation 614 
 
 693. Hockin's calciner, longitudinal section 615 
 
 694- P lan 615 
 
 695. Sampling quartering 633 
 
 696. shovel . . . 633 
 
 697. Clarkson's rapid sampler 635 
 
 698. Bridgman's ore-sampler, first apportioner 635 
 
 699. second 635 
 
 CONDITION OF WORKMEN. 
 
 700. Barracks for workmen, Eisleben, front elevation . . . 675 
 
 701. ,, ground plan .... 675 
 
 702. Cottage, Bolsover Collieries, front elevation .... 678 
 
 703. back 678 
 
 704. first floor plan .... 678 
 
 705. ground plan 678 
 
 706. Dry or changing house, Levant Mine, Cornwall, side elevation . 680 
 
 707. > j, plan . . 680 
 
 708. Shower-baths, Anzin Collieries, France 68 1 
 
 ACCIDENTS. 
 
 709. Lowmoor jacket and Furley pattern stretcher . . , .712 
 
 710. Placing stretcher on Ashford litter . . . . , . 713 
 
 711. Ashford litter , . . , 713 
 
LIST OF ABBREVIATIONS. 
 
 Ann. Mines. Annales des Mines. 
 
 Ann. Hep. JR. Cornwall Pol. Soc. Annual Report of the Royal Cornwall 
 Polytechnic Society. 
 
 B. u. h. Z. Eerg- und hiittenmannische Zeitung. 
 
 Bull Soc. Ind. Min. Bulletin de la Societe de 1'Industrie Minerale. 
 
 Coll Guard. The Colliery Guardian. 
 
 Comptes Bendus Mensuels, Soc. Ind. Min. Comptes rendus mensuels de la 
 Societe de 1'Industrie Minerale. 
 
 Eng. Min. Jour, or E. M. J. The New York Engineering and Mining 
 Journal. 
 
 Jahrb. f. d. Berg- und Huttenwesen im K. Sachsen. Jahrbuch f iir das Berg- 
 und Huttenwesen im Konigreiche Sachsen. 
 
 Jahrb. f. Geol. Min. Paldont. Jahrbuch fiir Geologic, Mineralogie und 
 Palaontologie. 
 
 Jour. Eoy. Inst. Cornwall. Journal of the Royal Institution of Cornwall. 
 
 Jour. Soc. Arts. Journal of the Society of Arts. 
 
 Jour. Soc. Chem. Ind. Journal of the Society of Chemical Industry. 
 
 Mem. Geol. Survey. Memoirs of the Geological Survey of Great Britain. 
 
 Min. Jour. Mining Journal. 
 
 Min. Stat. Mineral Statistics of the United Kingdom. 
 
 Neues Jahrb. f. Miner. Geol. u. Paldontologie. Neues Jahrbuch fiir 
 Mineralogie, Geologic und Palaontologie. 
 
 Oesl. Zeitschr.f. B.-u. H.- Wesen. Oesterreichische Zeitschrift fiir Berg- 
 und Huttenwesen. 
 
 Phil. Trans. Philosophical Transactions. 
 
 Proc. Fed. Inst. M. E. Proceedings of the Federated Institute of Mining 
 Engineers. 
 
 Proc. Inst. Civil Eng. or Proc. Inst. C. E. Proceedings of the Institution 
 of Civil Engineers. 
 
 Proc. Inst. Mech. Eng. or Proc. Inst. M. ^.Proceedings of the Institution 
 of Mechanical Engineers. 
 
 Proc. Min. Inst. Cornwall. Proceedings of the Mining Institute of Corn- 
 wall. 
 
 Proc. South Wales Inst. Eng. Proceedings of the South Wales Institute of 
 Engineers. 
 
 Quart. Jour. Geol. Soc. Quarterly Journal of the Geological Society. 
 
xxviii LIST OF ABBREVIATIONS. 
 
 Bee. Geol. Survey, India. Kecords of the Geological Survey of India. 
 
 Eep. Miners' Assoc. Cornwall. Keport of the Miners' Association of Corn- 
 wall and Devon. 
 
 Stat. Min. France. Statistique de 1' Industrie minerale en France. 
 
 Trans. Amer. Inst. M. E. Transactions of the American Institute of 
 Mining Engineers. 
 
 Trans. Inst. Eng. and Shipbuilders in Scotland. Transactions of the Insti- 
 tute of Engineers and Shipbuilders in Scotland. 
 
 Trans. Inst. Marine Eng. Transactions of the Institute of Marine En- 
 gineers. 
 
 Trans. Manch. Geol. /Soc. Transactions of the Manchester Geological 
 Society. 
 
 Trans. Min. Assoc. and Inst. Cornwall. Transactions of the Miners' Asso- 
 ciation and Institute of Cornwall. 
 
 Trans. Min. Inst. Scotland. Transactions of the Mining Institute of 
 Scotland. 
 
 Trans. N. of Eng. Inst. Min. Eng. Transactions of the North of England 
 Institute of Miniog and Mechanical Engineers. 
 
 Trans. E. Geol. Soc. Cornwall. Transactions of the Royal Geological 
 Society of Cornwall. 
 
 Trans. Technical Soc. Pac. Coast. Transactions of the Technical Society of 
 the Pacific Coast. 
 
 2'eitschr. d. d. geol. Gesellsch. Zeitschrift der deutschen geologischen 
 Gesellschaft. 
 
 Zeitschr. f. B.-H.-u. S. -Wesen. Zeitschrift fur das Berg- Hiitten- und 
 Salineuwesen im preussischen Staate. 
 
A TEXT-BOOK 
 
 OF 
 
 ORE AND STONE-MINING. 
 
 INTRODUCTION. 
 
 THE art of mining, in the broadest sense of the word, consists of 
 the processes by which the useful minerals are obtained from 
 the earth's crust. This definition is wide, for it includes under 
 the term " mine " both open and underground excavations ; but 
 it excludes subterranean workings which are simply used as 
 passages, such as railway tunnels, sewers, and galleries for military 
 purposes. 
 
 The word " mine " is derived from a low-Latin verb meaning 
 to lead, and equivalent to " ducere ; " we have the French word 
 '* mener," from the same source. No doubt originally the mineral 
 deposit itself was called the "mine" or " lead," and this signifi- 
 cation has not been entirely lost, for we still find the word " mine " 
 used as a synonym for " seam " in the case of coal and ironstone. 
 
 I must remark that the word " mine," or its equivalent in 
 other languages, varies in signification in different countries on 
 account of legal enactments or decisions which define it. In the 
 United Kingdom it is the nature of the excavation, and not the 
 nature of the mineral, which decides whether the workings are a 
 mine or not. For legislative purposes the term " mine " is restricted 
 to workings which are carried on below ground by artificial light ; 
 but in common parlance this rule is not ob>erved, and the word 
 used depends upon the mineral itself. Thus the underground 
 workings for building stone near Bath, and for slate at Festiniog, 
 are usually spoken of as quarries, but are treated legally as 
 mines. 
 
 In Belgium, France, and Italy, on the other hand, the work- 
 ings for mineral are classified according to the mineralogical 
 nature of the substance wrought. The French law of 1810 makes 
 three classes of workings : mines, minieres, and carrieres. Deposits 
 of gold, silver, lead, copper, sulphur, coal, and beds or veins of 
 iron ore form mines. Under the head of minieres, for which we 
 have no equivalent word in English, are included bog iron ore, 
 pyritous earths fit for working, sulphate of iron, aluminous earths 
 and peat, whilst the carrieres, or quarries, comprise workings for 
 
 A 
 
ORE AND STONE-MINING. 
 
 ^ etc., whether above or below ground. Tne 
 e of 1866 has assimilated the minieres to the quarries, and 
 the law now becomes very like that of Italy (1859), which distin- 
 guishes simply mines (miniere) and quarries (cave). Deposits con- 
 taining metallic ores (excepting metal-bearing sand or earth), 
 sulphur, bitumen, coal, or lignite are worked as *' mines," whilst pits 
 from which sand and gravel are obtained become legally "quarries. 1 ' 
 The consequence is that what is merely an underground stone 
 quarry in France would be a mine in England ; whilst open 
 workings for iron ore, such as those of Northamptonshire, would 
 be tiue mines under the French or Italian laws. 
 
 In a general text-book upon mining, it is therefore necessary to 
 go beyond the British definition of a mine and to include the 
 methods of working minerals in excavations open to the daylight, 
 as well as in those which are purely subterranean. 
 
 The mining of coal is a subject of so much importance, 
 especially in this country, that it requires a special treatise ; 
 this has been prepared by my friend, Mr. H. W. Hughes,* and 
 my task consists in describing the methods of winning and work- 
 ing all other useful minerals, whether solid, liquid, or gaseous. 
 Furthermore, as it is customary for the miner to cleanse or pre- 
 pare his ore or stone for sale, I shall explain the processes which 
 are usually carried on at the mine, and can be fairly included 
 under the convenient term "dressing." Finally, a few remarks 
 will be made concerning legislation affecting mines in the United 
 Kingdom, the condition of workmen, and the accidents to which 
 they are exposed. 
 
 The subject has been divided into the following chapters: 
 
 (1) Occurrence, or manner in which the useful minerals are 
 found in the earth's crust. 
 
 (2) Prospecting, or search for minerals. 
 
 (3) Boring. 
 
 (4) Excavation. 
 
 (5) Supporting excavations. 
 
 (6) Exploitation, or working away of minerals. 
 
 (7) Haulage, or transport along roads. 
 
 (8) Winding, or hoisting in shafts. 
 
 (9) Drainage, or removal of water. 
 (10) Ventilation. 
 
 (n) Lighting. 
 
 (12) Descent and ascent. 
 
 (13) Dressing. 
 
 (14) Principles of employment. 
 
 (15) Legislation. 
 
 (16) Condition of workmen. 
 
 (17) Accidents. 
 
 * A Text-Book of Coal Mining, London, 1892. 
 
( 3 ) 
 
 CHAPTER I. 
 
 MODE OF OCCUKRENCE OF MINERALS. 
 
 Classification of mineral repositories. Beds. Veins. Masses. Causes 
 affecting the p-oductiveness of veins. Theories concerning the 
 formation of veins. Examples of mineral deposits arranged alpha- 
 betically. Faults or dislocations. 
 
 CLASSIFICATION". Various conditions may be taken as 
 the bases of classification of the rocks which form the crust of the 
 earth. One striking characteristic is the presence or absence of 
 beds or layers. A rock made up of parallel beds, or layers, or strata, 
 is said to be stratified ; a rock in which no such structure exists 
 is called unstratified. When we examine the stratified rocks 
 closely, we find that, as a rule, they have been formed afc tho 
 bottom of seas, lakes, or rivers by the gradual deposition of 
 sediment, by precipitation from solutions, and by the growth or 
 accumulation of animal or vegetable organisms. As instances 
 may be cited beds of sandstone or clay, formed by particles of 
 sand or mud settling down in water ; beds of rock salt, resulting 
 from the gradual drying-up of inland seas ; beds of limestone, 
 formed out of old coral reefs ; beds of coal, due sometimes to plants 
 growing upon the spot and sometimes to plants washed into 
 lakes or estuaries. 
 
 The unstratified rocks are frequently crystalline. In the 
 case of recent volcanoes we see molten rocks issuing forth from 
 the earth, spreading over it, and consolidating into a crystalline 
 mass, and we may fairly assume that many of the crystalline 
 rocks now met with at the surface were at one time in a soft fused 
 condition. Internal evidence leads to the belief that the process of 
 consolidation often took place at a very great depth, and on this 
 account geologists have subdivided the crystalline unstratified 
 rocks into volcanic, which hardened like recent lavas near the 
 surface, &nd 2)lutonic, which became solid under the heavy pressure 
 of thick masses of superincumbent strata. 
 
 One class of crystalline rocks has given rise to much contro- 
 versy, viz., the rocks in which the crystals of the constituent 
 minerals are arranged in roughly parallel layers. The rock has a 
 flaky structure, and is known as a crystalline schist. Some 
 crystalline schists have all the appearance of being altered sedi- 
 
4 ORE AND STONE-MINING. 
 
 mentary strata ; in others the foliated structure is considered to 
 be the result of pressure upon pre-existing crystalline rocks. 
 We therefore may classify the principal rocks as follows : 
 
 {Sedimentary origin. 
 Chemical origin. 
 Organic origin. 
 
 ,.,. , ( Volcanic. 
 *. TJnstratiEed . J plutonic 
 
 The crystalline schists must be placed in one or other of these 
 two great divisions, according as they are looked upon as an 
 altered form of stratified or of unstratified rocks. 
 
 This classification is not entirely satisfactory. For instance it 
 separates two of the products of a volcano. Volcanic ash falling 
 into the sea will settle down and form a stratified rock, whilst 
 the lava issuing from the same vent is unstratified. Again it 
 does not include sea- water, an important source of salt. How- 
 ever, for the purpose of the miner a simple classification is 
 advisable, and it will be found sufficient for his purpose so long 
 as it is recollected that occasional anomalies must be expected. 
 
 Any one of the five classes of rocks just mentioned may be 
 extracted from the crust of the earth for commercial purposes. 
 
 Among the bedded or stratified rocks coal is the most im- 
 portant, but in addition we have beds which are commercially 
 valuable on account of the metals they contain, such as copper, 
 gold, iron, lead, manganese, silver, and tin, orpiecious stones such 
 as diamonds, garnets, rubies and sapphires ; other valuable beds 
 are native sulphur, rock-salt, and innumerable kinds of stone for 
 building, decoration, paving and road-making, clays for making 
 pottery and cement, oil-shale and alum-shale. 
 
 From the unstratified rocks we obtain supplies of stone for a 
 great variety of purposes. 
 
 In addition to mineral deposits, which consist mainly of 
 original constituent members of stratified or unstratified rocks, 
 we have a third important class in which the repository of the 
 valuable mineral has come iiito existence subsequently to the 
 consolidation of the rocks which surround it. If the repository 
 is, roughly speaking, tabular or sheet-like, it is called a mineral 
 vein or lode, and if in any other form it is a mass. 
 
 Hence the series of mineral repositories might be classed 
 according to their origin as follows : 
 
 Prhnavy origin . ( gg^. 
 
 , . . ( Veins. 
 
 Secondary origin . 
 
MODE OF OCCURRENCE OF MINERALS. 5 
 
 "But even here we encounter difficulties, for unstratified rocks 
 sometimes occur in the form of veins ; besides which primary 
 origin is not a term which is strictly applicable to beds formed 
 from sediment which consists of fragments of other rocks. 
 
 It is not unnatural, therefore, that outward form should have 
 been chosen as a convenient basis of classification, and accordingly 
 mineral repositories have been separated into : 
 
 Tabular or sheet-like . j y . 
 Non-tabular . . 3. Masses. 
 
 TABULAR DEPOSITS. These are repositories which have 
 a more or less flattened or sheet-like form. They may be divided 
 according to their origin into (i) beds or strata; (2) mineral 
 veins. 
 
 (1) Beds. The characteristic feature of a bed or seam is that 
 it is a member of a series of stratified rocks ; the layer above it is 
 called the roof, the one below it is the floor. Its thickness is the 
 distance from the roof to the floor measured at right angles to 
 the planes of stratification ; its dip is the inclination downward 
 measured from the horizontal; its strike is the direction of a 
 horizontal line drawn in the plane of stratification. 
 
 The thickness of workable beds varies within very wide 
 limits. The productive part of the copper-shale at Mansfeld is 
 only 3 inches to 7 inches thick ; and one of the beds of gold- 
 bearing conglomerate at Johannesburg is only 6 inches to 2 feet 
 across; we find, on the other hand, the lead-bearing sandstone of 
 Mechernich, in Rhenish Prussia, is 100 feet (30 m.), and a bed of 
 brown coal at Briihl in the same neighbourhood no less than 131 
 feet (40 m.) thick. The principal bed of slate at the Oakeley 
 Quarry, Festiniog, is 120 feet thick (36-5 m.). 
 
 It must not be supposed that the thickness of a bed necessarily 
 remains uniform. Occasionally this is 
 the case over a very large area; but Fm ' Im 
 
 frequently the thickness varies, and 
 the bed may dwindle away gradually, 
 or increase in size, or become divided 
 into two, owing to the intercalation of 
 a parting of valueless rock ; but, in 
 spite of such variations, a bed is much 
 more uniform in thickness and com- 
 position than a vein. Fig. i shows 
 
 beds of shale, limestone, iron ore and sandstone, any one of which 
 may be the object of a mining undertaking. 
 
 (2) Veins or Lodes. Veins or lodes are more or less tabular 
 or sheet-like mineral deposits, formed more or less entirely since 
 the enclosing rocks (country), and either occupy ing cavities formed 
 
ORE AND STONE-MINING. 
 
 FIG. 2. 
 
 originally by fissures, or consisting of rock altered in the vicinity 
 of fissures. A simple and typical example of a vein is shown in 
 Fig. 2, representing a lead lode in slate at Wheal Mary Ann in 
 Cornwall.* It is evident that a fissure in the slate has been 
 filled up by the successive deposition of bands of mineral on both 
 The unfilled cavities are called lochs (Wales and Isle of 
 Man), or vugsfr (Cornwall). The 
 definition given above differs some- 
 what from that of some standard 
 authors, whose opinions I will quote. 
 Werner says :J "Veins are special 
 tabular mineral repositories which 
 nearly always cut across the strati- 
 fication of rocks and so far have a 
 different lie to them, and are filled 
 with a mineral mass differing more 
 or less from the surrounding rocks ;" 
 and further, "Mineral veins may 
 
 be more exactly defined by saying that they are fissures in the 
 rocks which have been subsequently filled up with various 
 minerals differing more or less from the surrounding rock." 
 Game's definition is this : || "By a true vein, I understand 
 the mineral contents of a vertical or inclined fissure, nearly 
 straight, and of indefinite length and depth." Von Cotta's is 
 shorter :^[ " Mineral veins are the contents of fi.ssures," whilst 
 Grimm says :** " Veins are fissures in rocks which have been 
 wholly or partly filled with minerals." Von Groddeck's explana- 
 tion runs thus :tt " Veins are fissures which have been filled up." 
 In Geikie's text-book we find :J{ "A mineral vein consists of one 
 or more minerals deposited within a fissure of the earth's crust." 
 Prof essor von Sandberger's idea of a vein is the same : "True 
 veins, that is to say, fissures filled with ores." In France |||| and 
 similar definitions prevail. 
 
 * C. Le Neve Foster, "Remarks on the Lode at Whea] Mary Ann, Mtn- 
 heniot,' 1 Trans. It. Geol. >6'oc. Cornwall, vol. ix. p. 153. 
 
 t Probably taken from the Cornish word " fogou, 7 a cave. 
 
 | A. G. Werner, Neue TLeurie von der Entstehung der Gange. Freiberg, 
 1791. p. 3. 
 
 Ibid. 
 
 || J. Carre, "On ihp Relative Age of the Veins of Cornwall," Trans. It. 
 Geol. >Sbc. Cornwall. Penzance, 1822, vol. ii. p. 51. 
 
 IT Die Lehre von den Erzlagt-rstatten. Freiberg. 1859, p. 102. 
 
 ** Die Lagerstdtten der nutzlaren Miner alien. Prague, 1869, p. 97. 
 
 ft Die Lehre von den Lagerstdtten der Erze. Leiptic, 1879, p. 31. 
 
 +1 Text Booli of Geology. London, 1882, p. 591. 
 
 Untersuchungen tiler Erzydnge. Wiesbaren, 1882, p. 4. 
 
 || || Haton de la Goupilliere, Cours d 1 Exploitation des Mines. Paris, 1883, 
 
 P 33- 
 lilf V ZoppeUi, Arte Miner arm. Milan, 1882, p. 16. 
 
MODE OF OCCURRENCE OF MINERALS. 7 
 
 As long ago as the year 1864,* Mr. Richard Pearce brought 
 forward the theory that nrmy of the tin lodes of Cornwall have 
 been formed by the alteration of granite, and my own f investi- 
 gations have coriv'ncad me that he is right. The lodes appear 
 to be bands of stanniferous rock formed by the alteration of 
 granite in the vicinity of fissures. The tabular mass of tin-bearing 
 rock 10 or 15 feet thick, called the lode, is traversed by sundry 
 fissures and passes without any distinct walls or boundaries into 
 non-stanniferous granite; sometimes the main fissure is a few 
 inches wide filled with crystallised quartz and other minerals. 
 This filled-up crack answers to the common definition of a vein, 
 but the rest of the stanniferous mass does not. It has no definite 
 bounding planes, it contains no 
 
 fragments of the surrounding FIG. 3. 
 
 rocks, and presents no appear- 
 ance of having been formed 
 by the deposition of minerals 
 upon the sides of an open rent 
 (Fig. 3). As much of the stan- 
 niferous rock as will pay for 
 working is known as the lode. 
 I think the geologist must give 
 way and suit his definition to 
 the wants of the miner. It is too much to expect the miner to 
 give up a term consecrated by universal usage, simply because 
 geologists have made the mistake of supposing that all lodes have 
 been formed on the same plan. 
 
 If Cornwall furnished the only exceptions to the time-honoured 
 definition of a mineral vein, one would perhaps hesitate in pro- 
 posing any alteration ; but when similar or somewhat similar 
 cases are met with in other parts of the globe, the necessity for 
 some change becomes apparent. 
 
 Mr. Kendall J says that the haematite veins of the Lake District 
 (England) are not filled fissures, but are substitutional deposits, 
 the result of a gradual replacement of the original rock by other 
 minerals. 
 
 Mr. S. F. Emmons takes a similar view : " I consider it 
 reasonably certain that a very large proportion of the so-called 
 fissure- veins in the Rocky Mountain region, notably those in 
 
 * R. Pearce, " The Influence of Lodes on Rocks," Hep. Miners' Assoc. 
 Cornwall. Truro, 186), p. 18. 
 
 t C. LsNeve Foster, "On the Great Flit Lode South of Redruth and 
 Cimborne and on some othpr Tin-deposits formed by the alteration of 
 Granite," Quart. Jour. Geol. Soc., London, 1878, vol. xxxiv. pp. 640-653. 
 
 J J. D. Kendall, "On the Mineral Veins of the Lake District," Trans 
 Manch. Geol. Soc. Manchester, 1884, vol. xviii. p. 292. 
 
 R. C. Hills, "Ore Deposits of Summit District, Rio Grande County, 
 Colorado." Condensed for the Engineering and Mining Journal, by S. F. 
 Einmons. Enj. Min. Jovur. 18 3, vol. xxxv. p. 334. 
 
8 
 
 ORE AND STONE-MINING. 
 
 Colorado and Montana, are simply the alteration, silicification, 
 and mineralisation of the country rock along certain planes which 
 for some reason or other offered exceptionally easy access to per- 
 colating mineral solutions, and are not the filling up of pre- 
 existing cavities in the rock, as is generally supposed to be the 
 characteristic of a true fissure-vein." 
 
 Some of the lodes of Otago, New Zealand,* may be described as 
 
 belts or zones of auri- 
 
 FlG - 4- ferous mica-schist with- 
 
 ou t anv definite bound- 
 arie s ; Fi g- 4 shows one 
 of them,which is worked 
 at Canton mine. AA is 
 A a vein of quartz, BB a 
 channel or zone of dis- 
 turbed and distorted 
 schist, CO a false wall 
 or plane, along which 
 there has been a shift- 
 ing of the strata. The 
 vein A A, which has 
 been formed along one 
 of the lines of fracture 
 and dislocation, is called 
 the "indicator," as it 
 acts the part of a guide 
 to th3 miner in his en- 
 deavours to follow the 
 auriferous channel ; but 
 the precious metal is not 
 confined to the space 
 between A and C. 
 
 The question as to 
 what constitutes a vein 
 or lode has been more 
 thoroughly threshed out 
 in the United States 
 than elsewhere, because 
 in some parts of that 
 country the miner's 
 
 title to his property depends upon the definition of the word. 
 The consequence is that the term "lode" has been defined by 
 judicial decisions. 
 
 In the year 1877, Mr. Justice Field, in the celebrated Richmond 
 v. Eureka, case, gave the following interpretation f " We are of 
 
 * Kickard, "The Gold-fields of Otago," Trans. Amer. Inst. M. E. 
 Mpeting of June 1892. 
 t Transcript of Kecord. Supreme Court of the United States, Nos. 1038 
 
 CANTON MINE 
 
MODE OF OCCURRENCE OF MINERALS. 9 
 
 opinion, therefore, that the term lode, as used in the Acts of 
 Congress, is applicable to any zone or belt of mineralized rock 
 lying within boundaries clearly separating it from the neighbour- 
 ing rock." 
 
 This definition, which has been framed for the practical work- 
 ing of an Act of Congress, is not a satisfactory one for the 
 scientific miner, because it would include a bed or seam, whilst it 
 would exclude some of the Cornish tin lodes which have no distinct 
 boundaries. 
 
 Some subsequent decisions cover more ground, for they ignore 
 the question of shape. Judge Hallett * gave the following charge 
 in the case of Hyman v. The Aspen Mining and Smelting Company : 
 " It may be said that with ore in mass and in position in the 
 body of a mountain, no other fact is required to prove the 
 existence of a lode of the dimensions of the ore. As far as it 
 prevails, the ore is a lode whatever its form or structure may be, 
 and it is not at all necessary to decide any question of fissures, 
 contacts, selvage, slickensides, or other marks of distinction, in 
 order to establish its character. As was said in another case f in 
 this court : ' A body of mineral or mineral-bearing rock in the 
 general mass of the mountain, so far as it may continue unbroken 
 and without interruption, may be regarded as a lode, whatever 
 the boundaries may be. In the existence of such body, and to the 
 extent of it, boundaries are implied/ " 
 
 While quoting these decisions on account of their importance 
 to prospectors and to holders of mining property in the United 
 States, I think it wise to adhere, for the purposes of the student, 
 to the definition I have proposed, and to consider tabular shape" 
 and origin subsequent to that of the enclosing rocks as the chief 
 characteristics of mineral veins or lodes. No doubt a very large 
 number of mineral veins are simply the contents of fissures; 
 others are bands of rock impregnated with ore adjacent to fissures ; 
 others, again, have been formed by the more or less complete 
 replacement of the constituents of the original rock by new 
 minerals. 
 
 Yeins may occur in stratified or unstratified rocks, and in the 
 former they usually cut across the planes of bedding. 
 
 Like a bed, a vein has its dip and strike ; but as the dip of 
 veins is generally great, it is often measured from the vertical, 
 and is then spoken of as the underlie, underlay, or hade. Instead 
 of being expressed in degrees, the underlie is sometimes measured 
 by the amount a lode plunges under cover, or away from the vertical, 
 in a distance of i fathom (6 feet) measured along the dip. Thus 
 
 and 1039. The Richmond Mining Company of Nevada v. The Eureka Con- 
 solidated Mining Company. Appeal from the Circuit Court of the United 
 States for the district of Nevada, p. 604. Filed January 17, 1878. 
 
 "The Aspen Case," Eng. Min. Jour. New York, vol. xliii. 1887, p. 21. 
 t " The Smuggler Case," op. cit. p. 20. 
 
10 
 
 ORE AND STONE MINING. 
 
 if AB (Fig. 5) represents a lode, and AC = 6 feet, AD being verti- 
 cal, draw the line CE at right angles to AD, the inclination is 
 measured by the relation of EC to AC. 
 
 If EC = 2 feet the underlie is said to be 2 feet in a fathom. 
 This approaches very closely to a dip of 70, or 
 FTG. 5. underlie of 20, whilst i foot in a fathom, for most 
 practical purposes, corresponds to a dip of 80, or 
 underlie of 10. This method of expressing the dip 
 enables it to be determined with a rule or tape. If 
 AB (Fig. 6) is a lode at the end of a mining tunnel 
 (level), the miner has simply to measure the distance 
 EG = 6 feet, drop a stone from C and ascertain the 
 distance from D, where it falls, to E. However, 
 there is the disadvantage that some miners take the 
 standard fathom vertically and not along the dip ; 
 therefore, to avoid any chance of confusion it is 
 wiser to express the inclination of veins in degrees, 
 and not by " feet in a fathom." 
 
 The bounding planes of a vein, VY (Fig. 7), are called the walls 
 or cheeks, and they are frequently smooth and striated, showing that 
 one side must have slid against the other. These striated surfaces 
 are called slickensides. At the Halkyn mine, Flintshire, the 
 whole side of one of the levels, for a distance of ten yards, is a 
 smooth flat polished surface, with small striae, precisely like the 
 scratchings produced upon rocks by the action of glaciers. In 
 this particular case the striations are horizontal ; more frequently 
 they are inclined. The wall above a lode is called the hanjiny 
 
 r, c 
 
 wall, AB, the one underneath, the foot wall, CD. The rock 
 surrounding or enclosing the lode is called the country, EE. I 
 give this term, not because I wish to perpetuate a mere Cornish 
 provincialism, but because it has crept into use elsewhere. To 
 use the words country rock, as is done very frequently, is to be 
 guilty of tautology. I may here remark, once for all, that, as a 
 general rule, it is best to avoid local technical terms, and as far as 
 possible employ words which are understood by every one ; but 
 
MODE OF OCCURRENCE OF MINERALS. n 
 
 some expressions are so convenient on account of their brevity 
 that they may fairly be adopted into our language. It is not un- 
 common to find a layer of clay, FG, between the lode and the 
 enclosing rocks ; such a layer is called a selvage, dig (Cornwall), 
 gouge (U.S.), or alta (California). A large mass of the adjacent 
 rock found enclosed in the lode is called a horse, HH. 
 
 The valueless components of a lode which surround the ore are 
 often spoken of as forming the gangue. I mention the word in 
 order to enter a protest against its use, because, in its passage to 
 us from the German through the French, it has lost part of its 
 original meaning. We already have the words veinstone, lode- 
 stuff, and matrix, which are more strictly correct and more easily 
 understood than gangue, which, by Englishmen, should be con- 
 signed to oblivion. 
 
 Veins often continue for a great distance along their strike. 
 The Van lode in Montgomeryshire is known for a length of nine 
 miles, whilst the Great Quartz Vein in California has been traced 
 for a distance of no less than eighty miles. 
 
 Veins are of less uniform productiveness than beds, and are 
 rarely worth working through- 
 out. Rich portions alternate FIG. 8. 
 with poor or worthless portions. r s ^*j^, 
 The rich paits have received APIT UJVEL vt 
 various names according to the ^ "TS?"Sv'SS^ c.-?' '$$*'" 
 forms they assume : Fig. 8 re- "^^jfe ^-:^' .-^' 'f\ ^^ 
 presents a longitudinal section "^ft/^iyvf^ / J.^ V'^'" 
 
 along the strike of a lode, and IJT^JV *'""'" 
 
 the stippled parts are ore-bodies. so r*** u.v. Q/ .^S&B 
 BBB are bunches ; A is a large 
 
 bunch or course of ore ; when an ore-body forms a sort of con- 
 tinuous column we have a shoot (chute,TJ .&.), Ore-bodies which upon 
 being excavated leave chimney-like openings are called pipes (C). 
 In the United States the Spanish word bonanza, literally meaning 
 " fair weather " or " prosperity," is frequently used for a rich 
 body of ore. The inclination of a shoot in the direction of the 
 strike is called its pitch and sometimes its dip, though it is better 
 to restrict this word to the meaning it receives among geologists. 
 
 It is of the utmost importance to the miner to know where he 
 may expect to find a rich ore-body in a mineral vein. Experience 
 fehows that many conditions affect its productiveness,* viz. : 
 
 1. Intersections with other veins. 
 
 2. Nature of the adjacent rock. 
 
 3. Change of dip. 
 
 4. Change of strike. 
 
 * S<e also, L. Mdesemt, Clservations on tie Pacli Parts ofllicLo'esof 
 Cornwall. Translated from the French by J. H. Collins. London tnd 
 Truio, 1877. 
 
12 
 
 ORE AND STONE-MINING. 
 
 (1) Intersections of veins. AB (Fig. 9) is a vein intersecting 
 another CD at an acute angle AEG ; it is frequently the case that 
 there is an enrichment about the junction E. If the lines A'B', 
 
 C'D' represent the lodes at a lower 
 FIG. 9. level, then EE' indicates the line of 
 
 intersection, which may be the axis of 
 a shoot of ore upon one of them ; but 
 ^^^ when the angle AEG approaches a right 
 / """""- angle a favourable result is not ex- 
 
 c' , ^ / pected. 
 
 : .-V->-^__ tf If AB (Fig. 10) represents a section 
 
 ~"^- u . of a lode along the dip, and CD, EF, 
 and GH are small veins (feeders, drop- 
 pers) falling into it, an increase in the 
 productiveness of the lode often occurs near the intersection. 
 
 (2) Nature of the adjacent rock. Few facts are more generally 
 recognised than the influence of the enclosing rock upon the 
 productiveness of a lode. I will cite some well-known examples. 
 In the Alston Moor district the veins cross alternating beds of 
 limestone, sandstone, and shale ; they are generally more pro- 
 ductive in the limestone than in the sandstone or the shale. 
 
 At Kongsberg, in Norway, the silver veins are productive in the 
 
 FIG. 10. 
 
 FIG. ii. 
 
 fahlbands, that is to say, quartz schist, mica schist, hornblende 
 schist, and chlorite schist impregnated with iron pyrites and other 
 metallic sulphides, but are poor where they cross the gneiss. The 
 lines ABand CD in Fig. 1 1 represent two such veins in plan; the 
 portions ab and cd are worth working, but the other parts are not. 
 
MODE OF OCCURRENCE OF MINERALS. 13 
 
 In the Gympie* gold field, Queensland, the veins are richest 
 in certain bands of black shale. Four principal belts of black 
 shale have been recognised, and their influence is so thoroughly 
 known that " the fact has determined the system of mining on 
 the field." 
 
 Turning to another part of Australia, we may notice the 
 " indicators " at Ballarat.f These are narrow beds, some only 
 j inch thick, parallel to the planes of stratification of the 
 enclosing slate, and full of small cubical crystals of iron pyrites. 
 Their dip is nearly vertical, and they can be traced for miles. 
 When a quartz vein crosses an " indicator " there is usually rich 
 gold along the line of intersection. Mr. Charles King says: 
 " About ten of these * indicators ' are known within a width east 
 and west of 1,400 feet, and in the case of six out of these, the 
 quartz crossing them contains, at the line of intersection, exceed- 
 ingly rich patches of gold, frequently in nuggets many ounces in 
 weight." Why only six out of the ten indicators should have the 
 enriching effect is not stated. 
 
 A third instance of the enriching effect of a pyritiferous rock 
 is afforded in the Thames^ gold-tield of New Zealand, where, 
 instead of a narrow " indicator," there is a marked belt of rock, 
 60 to 80 feet thick, in which the veins prove remunerative. This 
 " congenial " bed is a felspathic sandstone containing pyrites, and 
 is probably a volcanic ash. The veins are poor, or die out 
 altogether on entering the harder diorite or underlying slate. 
 
 Even in the case of earthy minerals the same phenomenon 
 occurs. At Wotherton mine, in Shropshire, the barytes vein is 
 wide and worth working when the adjacent rock is volcanic ash, 
 but narrow and valueless in shale. 
 
 Lead veins in Derbyshire, which are productive in limestone, 
 rarely yield much ore in the loadstone, an interbedded lava. 
 
 (3) Change of dip. In a given vein the parts approaching 
 vertically are often noticed to be richer than those which are 
 comparatively flat. 
 
 (4) Change of strike. The veins of a mining district are com- 
 monly found to have the 
 
 same prevailing strike. FIG. 12. 
 
 Thus the tin and copper ______ _&_ _^ ^~~-^ -- / 
 
 lodes of the Camborne a ~* ~~^i^ "" : ^ 
 
 and Redruth districts, 
 
 Cornwall, usually run from S.S.W. to N.N.E., and are spoken of 
 
 * E. L. Jack, Annual Report of the Department of Mines, Queensland for 
 tlie year 1885. Brisbane, i86, p. 58. 
 
 t C. Le Neve Foster, " Mining Industries," fleports on tie Colonial Sec- 
 tions of the Exhibition. London, 1887, p. iS- 
 Op. tit. p. 35. 
 
 Kenwood, ' On the Metalliferous Deposits of Cornwall and Devon/' 
 /. Soc. Corn. Penzance, 1843, x l- v - P- 250. 
 
 Tram. It. Gcol 
 
14 OHE AND STONE-MINING. 
 
 as east and west lodes. Slight changes in the direction of the 
 strike are sometimes followed by variations in the productive- 
 ness ; in the case of a lode with an average strike repre- 
 sented by the dotted line a b, it may happen that the parallel 
 parts a b, c d, ef, are poor, and the parallel parts b c and d e 
 rich* (Fig. 12). 
 
 Too much stress must not be laid upon this question of strike, 
 because there are so many exceptions to the rule that a certain 
 strike is favourable. For instance, the two principal mines in 
 the Isle of Man, Laxey and Foxdale, are wrought, one upon a 
 north and south vein, the other upon an east and west vein, only 
 a few miles apart ; and at St. Just, in the extreme west of Corn- 
 wall, the mean direction of the lodes is 35 N. of W., and there- 
 fore quite different from what it is in the chief metalliferous 
 region ; but with individual lodes changes of strike should riot 
 unnoticed. 
 
 Formation of Mineral Veins. Though this book is intended 
 to deal mainly with the working of mines, a few remarks con- 
 cerning the origin of veins are necessary first, because the 
 posteriority of their formation is one of their chief characteristics ; 
 and, secondly, because a knowledge of the manner in which useful 
 minerals came to be concentrated along certain lines may enable 
 us some day to predict the precise spots where subterranean riches 
 are accumulated. 
 
 The principal theories are ; 
 
 1. Fracture and motion with mechanical filling. 
 
 2. Fracture and injection of molten matter. 
 
 [ (a) from above. 
 
 3. Fracture and deposition from solutions -j (b) from below. 
 
 ( (c) from the sides. 
 
 4. Fracture and sublimation, or deposition from gases. 
 
 (1) Mechanical billing. If a rock is fractured, and one side 
 of the crack slides against the other, a vein of crushed material is 
 formed. If the rock is shale or slate, the vein is a band of clay 
 more or less mixed with uncrushed fragments, and in Cornwall is 
 known as a.flookan. 
 
 (2) Injection. Veins formed by the injection of a molten or 
 plastic rock into fissures are usually known as dykes. 
 
 (3) Deposition from Solution. The lode at Wheal Mary Ann, 
 Cornwall (Fig. 2), is an instance of a vein formed apparently by 
 deposition from solution. Many of the common constituents of 
 mineral veins, such as silica, carbonate of calcium, sulphate of 
 barium, are known to be slightly soluble in water, whilst the 
 metallic sulphides can be formed by the reduction of a soluble 
 sulphate, or by the reaction of a soluble sulphide or sulphuretted 
 
 * Charles Thomas, Remarl^s on the Geology of Cornwall and Devon. ILd- 
 ruth, 1859, p. 5. 
 
MODE OF OCCURRENCE OF MINERALS. 15 
 
 hydrogen upon metallic compounds. Some metallic sulphides are 
 soluble in alkaline solutions. 
 
 Much discussion has arisen concerning the place whence the 
 mineral-bearing solutions came. The theory that they came 
 from above finds few upholders nowadays, and the battle rages 
 principally between the advocates of the ascensional theory, or 
 supposition that the minerals came up in solution from very 
 great depths, and the upholders of the lateral secretion theory, 
 in which it is assumed that they were leached out of the adjacent 
 rocks and re- deposited in the vein cavity. This latter theory' has 
 been powerfully espoused of late years by Professor Fridolin von 
 Sandberger,* who has pursued his investigations with great 
 ardour. He shows that small quantities of antimony, arsenic, 
 bismuth, cobalt, copper, lead, silver, and tin are contained in 
 silicates such as augite, hornblende, mica, and olivine, which are 
 essential constituents of plutonic and volcanic rocks; and he 
 concludes that these rocks are the sources from which the lodes 
 have derived their riches. 
 
 Prof, von Sandberger's views have not been allowed to pass 
 unchallenged, for Prof. Alfred Stelznerf combats his methods of 
 analysis. 
 
 It is naturally impossible to affirm with certainty that a given 
 mineral, such as mica, contains lead for instance, so long as there 
 is a possibility that particles of galena were mixed with it. The 
 absolute freedom of the rocks submitted to analysis, from any 
 mechanical admixture with pyrites or other sulphides is a neces- 
 sary foundation-stone of von Sandberger's theory. It is against 
 this point that Professor Stelzner directs his attack, and he shows, 
 by the results of numerous carefully conducted experiments, that 
 the metals found on analysis by Professor von Sandberger did not 
 necessarily come from the silicates, but may have been derived 
 from mechanically mixed sulphides which had resisted his 
 attempts to remove them. Stelzner points out that the occurrence 
 in the country of sulphides, similar to those existing in the lodes, 
 may be explained quite as well by their having travelled from the 
 fissure into the adjacent rock, as in the reverse direction. 
 
 With reference to the silver found in the rocks, Stelzner re- 
 marks that the mica of granite at S ilzb'achle in the Black Forest, 
 stated by von Sandberger and others to contain o'ooi to 0*006 
 per cent, of silver, was found to be absolutely free from any 
 traces of the metal when assayed with special precautions at the 
 Mining College of Freiberg. 
 
 Under these circumstances von Sandberger's theories must for 
 the present be looked upon as not entirely proven, much as one 
 
 * Untersuchungen iiber Erzc/iinge. Wiesbaden, 1882 and 1885. 
 
 t " DieLateralsecierions-Theorie und ih e Bedeatung fur das Pfibramer 
 Ganggebiet," Jahrbuch der k.k. fieryalcadcmien zu Lcoben und Pfibram und 
 der kgl. uny. Beryaladcinie zu tic/tcmnilz, vol. xxxvii. 
 
1 6 ORE AND STONE MINING. 
 
 would like to be able to account in so direct a manner for the in- 
 fluence of the country upon the contents of the lodes. 
 
 The views of Mr. Becker,* with reference to the quicksilver 
 mines of California and Nevada, deserve special mention, because 
 the adherents of both parties will probably claim them as support- 
 ing their theories. To avoid any chance of mistake, I quote ver- 
 batim : " The evidence is overwhelmingly in favour of the supposi- 
 tion that the cinnabar, pyrites, and gold of the quicksilver mines 
 of the Pacific slope reached their present positions in hot solutions 
 of double sulphides, which were leached out from masses under- 
 lying the granite or from the granite itself." Mr. Becker 
 supposes that the hot alkaline solutions were the products of 
 volcanic agencies, and he decidedly leans to the view that they 
 took up the heavy metals in their passage through the granite 
 itself, and not from rocks underlying it. 
 
 Even if the ore was not leached out of the immediately adjacent 
 rocks, these may have influenced its deposition either chemically 
 or mechanically. It is possible that a certain bed may act as 
 a reducing agent upon a solution which touches it, and so cause 
 precipitation; this may be the reason why rich gold has been 
 deposited where the pyritiferous "indicators" intersect the 
 Ballarat lodes. The mechanical effect is also very simple. A fissure 
 formed in a soft rock is likely to be filled up by pieces of the 
 sides dropping in, especially if there is any sliding of the hanging 
 wall upon the foot wall ; on the other hand, if the rock is hard, 
 the chasm will remain open and leave a space for the reception 
 of ores. This fact gives a reason for the steep parts of lodes being 
 sometimes richer than the flatter parts. If a wavy cut is made 
 in a piece of card or paper to represent the fissure, and the 
 " hanging wall " slid down a little, we have open spaces where 
 the fissure is steep, whilst the "walls" touch where the fissure is 
 flatter, leaving no room for any deposition of ore to take place. 
 A wavy crack of this kind may be caused by variations of hard- 
 ness and fissility, such as happen when shale is interbedded with 
 limestone ; here the crack will be propagated more readily along 
 the planes of stratification of the shale than across them. After 
 a slight shift of the " hanging wall " downwards, the cavities in 
 the limestone become receptacles for mineral deposits, whilst the 
 crack contains little but crushed rock in the shale. 
 
 In a like manner the variation in productiveness noticed upon 
 a slight alteration of strike may be due to change in the nature 
 of the " country," which not only caused a deviation from the 
 general direction of the fissure, but also affected its ore-bearing 
 qualities. Here, too, we find an explanation of the phenomenon 
 called "ore against ore." In Fig. 13 let ABCD, and EFGII 
 
 * "Geologry of the Quicksilver Mines of the Pacific Slope," Monograph* 
 of Ike U.S. Gcol. S'irvc.y, vol. xiii. p. 449. Washington, 
 
MODE OF OCCURRENCE OF MINERALS. 17 
 
 represent a plan of two parallel lodes, BC and FG being rich parts; 
 
 the miner notices that an improvement in the productiveness takes 
 
 place in both lodes when the strike changes from E. and W. to E. 
 
 25 N., and that the rich part. BC, is opposite the rich part FG. 
 
 This is not surprising if the parts BC and FG are in a special belt 
 
 or zone, included 
 
 between the lines FIG. J 3- 
 
 HK, LM, capable ,u 
 
 of exerting either a , ^ 
 
 mechanical effect * \ 
 
 upon the size of the 
 
 vein-cavity by its 
 
 hardness, or a 
 
 chemical effect by 
 
 its composition. 
 
 The adjacent rock 
 may likewise have 
 affected the lode by 
 its porosity or by its 
 impermeability, in 
 the former case by 
 affording an easy channel for the solutions which brought in the 
 minerals, and in the latter by interposing a dam which prevented 
 or delayed their escape. 
 
 (4) Sublimation. The sublimation theory meets with little 
 favour nowadays, though certain minerals known as constituents 
 of lodes are formed in furnaces, or can be produced artificially 
 from gases. Nearly half a century ago, Daubree * produced 
 crystals of oxide of tin by passing a current of stannic chloride 
 together with steam through a red-hot porcelain tube. One great 
 objection to the universal acceptance of the sublimation theory is 
 that many of the minerals found in lodes would be decomposed at 
 high temperatures. 
 
 Formations. The lodes in some districts are grouped into 
 different classes according to their mineralogical characters, and 
 careful observations have shown that those which are similar in 
 mineral contents usually agree in strike and in age. Distinctions 
 of this kind have been skilfully worked out at Freiberg f in 
 Saxony, where six of these classes or " formations " are recognised. 
 
 Anomalies. It must be understood that we cannot expect Nature 
 to make distinct lines of demarcation between the different kinds of 
 mineral repositories. Though we may be able to see clearly that 
 
 " Recherches sur la production artificielle de quelques esp&ces minerales 
 cristalline, particulierement de 1'oxyde d'etain, de 1'oxyde de titane et du 
 quartz. Observations sur 1'origine des fllons titaniferes des Alpes." Ann. 
 Mines, 49 serie, vol. xvi, 1840, p. 129. Compt. Rend., vol. xxix. 1849, 
 p. 227, and vol. xxx. 1850, p. 383. 
 
 t Freiberys Berg- und Hiittenwesen. Freiberg i. S., 1893, p. 32. 
 
 u 
 
i8 ORE AND STONE MINING. 
 
 a seam of coal is contemporaneous with the enclosing rocks, and 
 that a vein, intersecting successively beds of limestone, shale, and 
 sandstone, is evidently of later formation, cases frequently occur 
 in which the origin of the mineral is uncertain. 
 
 For example we have the lead-bearing sandstone of Mechernich, 
 the silver -bearing sandstone of Utah, the gold-bearing conglomerate 
 of the Transvaal. The grains of sand and the pebbles of quartz 
 are unquestionably of sedimentary origin ; but opinions differ 
 as to whether the lead, silver, and gold were deposited originally 
 with the sand and gravel, or were introduced subsequently by 
 metal-bearing solutions, which found a passage through the beds. 
 It has been shown by Mr. Becker* that ample space exists in an 
 ordinary sandstone for the deposition of ores. Supposing that 
 all the grains were true spheres of the same size, and as closely 
 packed together as possible, there would be 26 per cent, of inter- 
 stitial space. If this space is even partly occupied by an ore, the 
 percentage of metal may very easily be sufficient to render the 
 stratum worth working. For example, a sandstone with a specific 
 gravity of 2*25 requires only 3-7 per cent, of its interstitial space 
 to be filled by cinnabar with a specific gravity of 8, in order to 
 furnish an ore with 10 per cent, of mercury, about the average 
 contents of the rock worked at Almaden. This 3-7 per cent, is " less 
 than half the interstitial space in some indurated sandstones 
 employed for paving streets." In the case of sandstones worked 
 for mercury, it seems to be quite certain that the cinnabar was 
 brought in by aqueous solutions long after the deposition of the 
 sediment indeed, long after the solidification and upheaval of 
 the rocks. 
 
 According to Dr. Sorby, the iron of the well-known Cleveland 
 bed was " derived partly from mechanical deposition and partly 
 from subsequent replacement of the originally deposited car- 
 bonate of lime."t 
 
 Other cases of more or less complete replacement may be cited. 
 We find chalk changed into flint, limestone into chert; and if 
 " subsequent origin " were the only characteristic distinguishing a 
 vein from a bed, we should be landed in a difi cu'ty. It will be 
 found convenient to consider as seams any stratified deposits in 
 which the impregnated, altered, or pseudomorphous mass occupies 
 the position of an original bed, and to call the sheets veins when 
 they cross the bedding-planes, or occupy a fissure, or have been 
 formed by the alteration of a rock at the side of a fissure. 
 
 MASSES. These are deposits of mineral, often irregular in 
 shape, which cannot be distinctly recognised as beds or veins. 
 Such, for instance, are certain of the red haematite deposits of 
 
 * " Geology of the Quicksilver Deposits of the Pacific Slope," Monographs 
 of the U.S. Geol. Survey, vol. xiii. p. 399. Washington, j888. 
 
 f Quart. Jour. Geol. Soc.. vol. xxxv., 1879, p. 85. Anniversary Address 
 of the President. 
 
MODE OF OCCURRENCE OF MINERALS. 19 
 
 the Ulverston district (Fig. 14),* which occupy irregular cavities 
 in the Carboniferous Limestone. They may have been formed 
 
 FIG. 14. 
 
 ORDNANCE DATUM 
 
 U>#V , B / ''''^j' 60 FATHOMS UEV E L 
 
 A, the enclosing limestone ; B, red haematite ; C, sand and clay ; 
 D, a thick capping of glacial drift. 
 
 by the percolation of water bringing down iron in solution from 
 overlying rocks, which by gradual replacement changed part of 
 the limestone into a mass of haematite. Other examples of masses 
 are the calamine deposits of Altenberg (Fig, 15),! Sardinia, and 
 
 FIG. 15. 
 
 FIG. 1 6. 
 
 B, the enclosing slate, d, 
 dolomite, C, calamine, L, clay. 
 
 Mulberry Mine, near Bodmin. 
 
 Lombardy, the huge upright " necks " or " pipes " of diamond- 
 bearing rock in South Africa, and the granite decomposed in situ 
 worked for china clay in Cornwall. 
 
 Under this head also are included by most authors the so-called 
 " stockworks," " reticulated masses " or " network deposits," 
 names applied to masses of rock intersected by so many little 
 veins as to make the whole worth excavating. 
 
 Fig. 1 6 shows a number of steeply dipping strings of cassi- 
 terite, generally only two or three inches apart, intersecting beds 
 
 * " Beschreibung der Rotheisenerzlagerstatten von West Cumberland 
 und North Lancashire," /Stahl und Elsen, 2 Jahrgang, No. 12, Plate VI. 
 
 t M. Braun, Zeitsclir. d. d. geol. Gesellsch., vol. ix. (1857) ; and A. von 
 Groddeck, Die Lehre von den Laijerstatten der Erze. Leipsic, 1879, p. 242. 
 
20 OKE AND STONE-MINING 
 
 of slate. The mass of rock penetrated by this network of little 
 tin veins is 300 yards long by more than 30 yards wide, and the 
 whole of the stanniferous stone is quarried and stamped.* 
 
 EXAMPLES. These abstract definitions are not sufficient ; 
 the student should see how they can be applied to particular cases ; 
 and I now propose to give a series of examples of the modes of 
 occurrence of the most important minerals. As the same mineral 
 may be found in a bed, a vein, or a mass, it is simplest, for the 
 purposes of the miner, to classify these examples alphabetically. 
 I therefore arrange the information about tin, for instance, under 
 one head, instead of separating the tin veins from the stockworks, 
 and these from the alluvia. The minerals to which I propose to 
 refer are : 
 
 Alum, amber, antimony ore, arsenic, asbestos, asphalt, 
 barytes, borax, boric acid, carbonic acid, clay (including china 
 clay, fire clay, fuller's earth, potter's clay), cobalt ore, copper ore, 
 diamonds, flint, freestone, gold, graphite, gypsum, ice, iron ore, 
 iron pyrites, lead ore, manganese ore, nitrate of soda, ochre, oil 
 shale, ozokerite, petroleum, phosphate of lime, potassium salts, 
 quicksilver ore, salt, silver ore, slate, stone, strontium sulphate, 
 sulphur, tin ore, zinc ore. 
 
 Alum. The alum-stonef obtained at Allumiere and Tolfa. near 
 Civita Vecchia, occurs in very irregular veins, which are supposed 
 to be due to the action of heated water and sulphurous gases upon 
 the felspar contained in trachyte. 
 
 An important deposit of alunite has lately been discovered^ 
 in New South "Wales, at the Bullahdelah Mountain, which 
 rises up from the bank of the Myall River, a tributary of 
 Port Stephens. Marked cliffs, overlooking the river, consist of 
 alunite in varying quality, ranging from pure alunite to a mineral 
 in which there is as much as 40 per cent, of silica. The deposit 
 is traced for over a mile in length and nearly three-quarters of a 
 mile in breadth, the thickest band of stone being from 60 to 70 
 yards in width. The average composition of the rock now being 
 worked is as follows : 
 
 Per ceut. 
 
 Water 7-80 
 
 Alumina . . . .... 3470 
 
 Oxide of iron i 'oo 
 
 Potash 6'io 
 
 Sulphuric acid 32-30 
 
 Silica 18-10 
 
 lOO'OO 
 
 * C. Le Neve Foster, " On some Tin Stockworks in Cornwall," Quart. 
 Jour. Geol. Soc. t vol. xxxiv., 1878, p. 655. 
 
 t A. K, de la Grange, Le Trachiti delta Tolfa e le formazioni alluminifere. 
 Rome, 1 88 1. 
 
 t MS. information from Mr. S. Herbert Cox, A.R.S.M., the discoverer of 
 the alunite. 
 
MODE OF OCCURRENCE OF MINERALS. 21 
 
 The surrounding rocks belong to the Carboniferous system of 
 New South Wales, and it is supposed that the alunite has been 
 formed by solfataric action upon dykes of a felsitic rock. 
 
 Amber. This fossil resin is found in a bed of Tertiary age, 
 which extends along the shores of the Baltic from Western 
 Russia to Denmark. The principal workings are about halfway 
 between Memel and Dantzig, and the amber is obtained by diving 
 and dredging in the sea and by ordinary mining inland. After a 
 storm pieces are cast up on the shore. The stratum containing 
 the amber is known from its colour as the " blue earth." 
 
 Antimony. Antimony ore usually occurs in veins. In York 
 County, New Brunswick,* the veins are from a few inches to 
 6 feet wide in Lower Silurian slate. The veinstone is white 
 quartz, calcite, and iron pyrites in small crystals. The ore raised 
 from the mine contains about 10 per cent, of stibnite. 
 
 Arsenic. The white arsenic of commerce is mainly obtained 
 from mispickel, which is either mined by itself or more commonly 
 in connection with the ores of copper, tin, or gold. It is there- 
 fore in most cases a by-product in the preparation of these ores 
 for the market. 
 
 Asbestos. The asbestos of commerce is in part chrysotile and 
 in part the fibrous variety of hornblende. Italy and Canada are the 
 chief sources of supply, and in both countries the mineral is found 
 in veins in serpentine. The principal Italian mines are in the Susa 
 and Aosta valleys and the Valtellina.f In one of the mines in 
 a tributary of the latter valley the rock is " cut in every direction 
 by thin seams of asbestos, which seem to start as from a centre 
 and spread out in every direction, and these again are traversed 
 by thin seams both horizontally and diagonally. Entering into 
 the rock, these seams generally converge to a centre, where 
 the various thin seams unite themselves, and here a pocket of a 
 ton or a ton and a half of asbestos may be found, and then all 
 appearance of its presence ceases. Continuing to work inwards, 
 the seams generally re-appear and spread themselves out as 
 before." 
 
 The most important of the Canadian quarries are situated in 
 the townships of Thetford and Coleraine, in the province of 
 Quebec. A belt of serpentine runs through the district, and it is 
 intersected by innumerable small veins of chrysotile, varying in 
 width from a mere knife-edge to about 6 inches at the most, 
 the fibres of the mineral running almost at right angles to the 
 walls. The common width of the veins is from i to 2 inches, and 
 as they "cross and recross each other in every direction and at 
 
 * E. M. /., vol. xvi., 1873, P- 7 ; and B- u - & Z. 1874, p. 237. 
 
 t James Boyd, " Asbestos and its Applications," Jour. Soc. Arts, 
 vol. xxxiv. (1886), p, 583. J. A. Fisher, "Mining, Manufacture and Uses 
 of Asbestos," Trans. Inst. Marine Eny., vol. iv., 1892. 
 
22 ORE AND STONE-MINING. 
 
 every angle," * the whole of the enclosing rock has to be quarried 
 in order to get out the asbestos. 
 
 Asphalt. The various modes of occurrence of asphalt or 
 bitumen have been described by Malof and Greene,J and the 
 following table is made up from their works : 
 
 State. Localises. 
 
 I viscous . . Pitch springs in Alabama, France, 
 Venezuela, 
 solid . . Dead Sea, Cuba, Texas, Utah. 
 
 2. Mixed with earthy matter . Pitch Lake, Trinidad. 
 
 3. Mixed with sand . . , California, France, Utah. 
 
 (bituminous sandstone) 
 
 4. Impregnating limestone , Colorado, Cuba, France, Mexico, 
 
 (bituminous limestone) Sicily, Spain, Switzerland. 
 
 The nearly pure asphalt does not occur in sufficiently large 
 quantities to be worked on a commercial scale, and the Pitch 
 Lake of Trinidad. long known as a natural wonder, has not 
 been utilised to any great extent until of late years. The lake 
 occupies an area of 99 acres, and is on an average from 20 to 30 
 feet deep. Its surface is not one continuous sheet, but is broken 
 up by pools and channels of rain water ; the asphalt is nearly 
 everywhere solid enough to walk on. The crude asphalt has the 
 following composition :|| 
 
 Per cent. 
 
 Bitumen , 34 
 
 Water 30 
 
 Clay 36 
 
 100 
 
 " The bituminous sandstone of California is found in large 
 quantities at various points between Ban Francisco and Los 
 Angeles. It contains about 12 to 18 per cent, of bitumen, and 
 the rest is quartz sand, in grains about one-tenth of an inch in 
 size."^] 
 
 We now come to the bituminous limestone. Yal-de-Travers, 
 in Switzerland, and Seyssel, in France, are the most important 
 sources of this rock for paving purposes. At Seyssel there are 
 no less than seven beds of bituminous limestone, varying from 10 to 
 20 feet (3 to 6m.) in thickness. One analysis of the rock** was as 
 follows : 
 
 * Boyd, op. cit. p. 586. 
 
 t Leon Malo, L'Asphalte, Paris, 1888, p. 20, 
 
 t F. V. Greene, "Asphalt and its Uses." Tram. Am.Inst. 31. E., vol. xvii. 
 1888, p. 355. 
 
 Wali, ficport on the Geology of Trinidad. London, 1860, pp. 94, 140. 
 
 !| Malo, op. cit., p. 75. IT Greene, op. cit. 
 
 ** Notice sur la Societt civile de bitumeet d'asplialte du Centre. Paris, 1889, 
 p. 7. 
 
MODE OF OCCURRENCE OF MINERALS. 23 
 
 Per cent. 
 Bitumen . . . . . . ,.670 
 
 Clay 3 xx> 
 
 Peroxide of iron ..... 2*60 
 Lime . . . . . . . 45 - oo 
 
 Magnesia 3-30 
 
 Sulphuric acid o'2O 
 
 Phosphoric acid . . . . o'2O 
 
 Carbonic acid, water and loss . . 38*60 
 
 99-60 
 
 Barytes. This mineral frequently accompanies lead ore, but 
 veins are sometimes worked for it alone, as at Wotherton in 
 Shropshire. 
 
 Borax. The American borax deposits* now being worked are 
 situated in a vast depression known as the Great Basin, which 
 exists between the Sierra Nevada on the West and the Rocky 
 Mountains on the East. Much of the region is a desert with 
 rivers and lakes which have no visible communication with the 
 ocean. The rivers lessen in volume gradually from absorption 
 and evaporation, and end in lakes. During the rainy season soda is 
 dissolved out of felspars contained in the lava which covers much 
 of the country, and in the dry season the salts of soda crystallise 
 out at the surface in the form of efflorescent crusts, 12 to 18 
 inches in thickness. The rain dissolves th<* crust, which is carried 
 away in solution into the rivers, and eventually into depressions 
 which form saline lakes. 
 
 The two principal deposits, known as Borax Lake and Teel's 
 Marsh, were discovered in 1873 ; the former lies in the Mojave 
 desert in California, 450 miles S.E. of San Francisco, and the 
 latter is in Nevada. The Borax Lake is oval in shape, its 
 greatest length and greatest breadth being 1 2 miles and 8 miles 
 respectively (Fig. 17). The greater part of the lake is covered 
 with a hard crust from a few inches to several feet in thickness, 
 consisting of various salts. On the top of this crust there is 
 usually white efflorescent matter mixed with sand, whilst under it 
 is black mud containing much iron sulphide, saline matter, and 
 sulphuretted hydrogen. 
 
 The lake may be divided into three sections, containing respec- 
 tively: (i) borax, (2) bicarbonate of soda, (3) common salt. 
 Near the centre of the borax section, an area of about 300 acres 
 is covered with water, i inch to i foot deep, and the mud under- 
 neath is full of large crystals consisting of carbonate of soda and 
 common salt, with a large proportion of borax. The ground 
 around this " crystal bed " is a dry hard crust containing car- 
 bonate and sulphate of soda and i per cent, of borax. Upon this 
 hard crust there is efflorescent matter containing on an average : 
 
 * C, Napier Hake, "An Account of a Borax Like in California," Journ. 
 Sue. Chem. IncL, vol. vdi. (1889), p, 854. 
 
24 OEE AND STONE-MINING. 
 
 Per cent. 
 
 Sand , 50 
 
 Sulphate of soda 16 
 
 Common salt . . . . , .12 
 Carbonate of soda . . . . .10 
 Borax 12 
 
 This surface efflorescence, which is about an inch thick, is 
 scraped off with shovels and swept into windrows, leaving space 
 
 FIG. 17. 
 
 Borax Deposit. 
 
 BI- Carbonate of Soda 
 
 Chloride of Sodium &c 
 
 enough between them for a cart to pass. When the surface has 
 been cleared, the moisture finds its way up again by capillary 
 action and is evaporated by the sun. The formation of the 
 
MODE OF OCCURRENCE OF MINERALS. 25 
 
 efflorescence is allowed to go on for three or four years, and then 
 the new crop is scraped off. The sand is blown on by high 
 periodical westerly winds. 
 
 The question naturally arises : Why is the borax mainly con- 
 fined to one part of the lake ? It appears necessary in order 
 to produce the efflorescence that the crust should touch the 
 water, so as to get a supply of the saline matter. The borax 
 section is the lowest part of the lake, and the hard crust dips into 
 the water. When the level of the water is low during a very dry 
 season, the formation of the efflorescence goes on slowly or ceases 
 altogether. In addition to borax there are sundry deposits of 
 borate of lime in the same region. 
 
 Boric Acid. Boric acid is obtained in considerable quantities 
 from gaseous emanations which come to the surface through in- 
 numerable fissures, probably dislocations, in the Eocene and 
 Cretaceous rocks of Central Italy.* The best known localities 
 are the four contiguous parishes of Pomarance, Castelnuovo di 
 Yal di Cecina, Massa Marittima, and Montieri, in the province of 
 Pisa. A pit is dug around any natural " steam-puff," or " blower " 
 (soffione), water is run in, and the steam and other gases, which 
 boil up through it, leave a little boric acid in solution. The 
 gases that escape are steam, a good deal of carbonic acid and 
 nitrogen, some oxygen, and a little sulphuretted hydrogen. The 
 very weak boracic solution is concentrated by heat derived from 
 some of the steam-puffs. The total production of the provinces 
 of Pisa and Grosseto in 1891 was 1775 metric tons of boric 
 acid, worth .35,500, and 2056 tons of borax worth "53,456. 
 
 Carbonic Acid. Liquefied carbonic acid is now a regular 
 article of commerce, and Germany has taken the lead in utilising 
 the natural supplies of the gas. In 1883 a bore-hole was put 
 down for carbonic acid at Burgbrohl,t near Andernach on the 
 Rhine, and since then others have been made at Obermendig, 
 Tonnistein, Honningen, and Gerolstein. All have been successful ; 
 they show that the subterranean supplies of carbonic acid are very 
 plentiful, and that in places where the gas is already known to 
 issue, nothing but a comparatively shallow hole is needed to 
 increase the quantity very considerably. 
 
 At Honningen, about five-eighths of a mile (i kilometre) from 
 the Rhine, an emanation of carbonic acid gas had long been 
 known, and was piped off to compression works before any boring 
 had been made. The rocks in which the carbonic acid occurs 
 at Honningen consist of greywacke and clay-slate, with vein-like 
 masses of quartz ; they belong to the Lower Devonian or so-called 
 
 * Jervis, Guida cdle Acque Miner all dltalia, Turin, 1868, p. 121 ; and 
 7 Tesori sotterranei deW Italia, Turin, 1874, p. 427. 
 
 t Heusler, /Sitzunc/sberichte der niederrheinischen Gcsellschaft fur Natur- und 
 llt'dhunde in Bonn. Meeting of July 9, 1888. 
 
26 ORE AND STONE-MINING. 
 
 Coblentz beds, and the bore-holes at Burgbrohl, Obermendig, and 
 Tonnistein have been put down in strata of the same age. 
 
 The Honningen hole was bored with a diameter of 13 inches 
 (33 cm.) to a depth of 230 feet (70 m.) from the surface. The 
 first water containing carbonic acid was met with at a depth of 
 92 feet (28 m.), and it still remains at this level. The quantity 
 of gas is greater than was given off by the old emanation at 
 the surface, and is reckoned to be 500 litres (nearly 18 cubic feet) 
 per minute, corresponding to 720 cubic metres (25,428 cubic feet) 
 of gas, or i kilog. (2*2 Ibs.) of liquid carbonic acid in twenty-four 
 hours. 
 
 The Honningen spring differs from some others by the fact that 
 at a depth of 230 feet (70 m.) the water is already at a tempera- 
 ture of 72 F. (22 C.), and probably a higher temperature would 
 be reached if the hole were deepened. A second hole has been 
 bored to a like depth by another company at a distance of 50 feet 
 (15 m.) from the first, and a good supply of gas has been 
 obtained. 
 
 At Gerolstein the bore- hole passed through alluvial gravel into 
 solid dolomite, and was stopped at a depth of 156 feet (47 J m.). 
 It seems probable that the hole has penetrated into a wide fissure 
 filled with loose fragments of dolomite. The water which flows 
 out contains such an excess of carbonic acid that it froths up at 
 the surface. The quantity of water coming up is 8476 cubic feet 
 (240 cb. m.) iii twenty-four hours, with an estimated minimum of 
 1060 cubic feet (30 cb. m.) of carbonic acid gas per hour. 
 
 Though natural outflows of this gas are common, especially in 
 volcanic regions, the number of places where they are utilised 
 commercially is small. In addition to the German localities, I 
 may mention two places in Italy.* There are springs of water 
 impregnated with carbonic acid and emanations of the gas at 
 Cinciano, in the Yalle d'Elsa, province of Siena, which are used 
 for making pure bicarbonates of potash and soda from the crude 
 carbonates, and also for making white-lead from the acetate, 
 the gas being perfectly free from any sulphuretted hydrogen. 
 Similar blowers (sojjioni) at Montione, near Arezzo, are em- 
 ployed for the latter purpose. 
 
 Clay (including common clays, china-clay, fire-clay, fuller's 
 earth, pipe-clay, potter's clay). 
 
 As a rule, clay occurs in the form of stratified deposits, and this 
 is the case with an important British clay, the fire-clay of the Coal 
 Measures, which is found in beds sometimes several feet in thick- 
 ness and usually under a seam of coal. The coal is often too thin 
 to be worked and may be only i inch thick, but both coal and the 
 underlying fire-clay may be worth working together. Various 
 beds of clay of Secondary and Tertiary age are dug in England 
 
 * Jervis, Gaida idle Acqu" Miner all d 1 Italia. Turin, 1868, pp. 54, 63. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 27 
 
 for making pottery, drain pipes, and Portland cement. The beds 
 
 of fuller's earth near Bath are of Oolitic 
 
 age, 
 
 whilst those which 
 
 are mined in Surrey belong to the Lower Greensand. 
 
 The china clay* of Cornwall and Devon exists in irregular 
 deposits of a totally different nature ; they consist of granite 
 decomposed in situ, not by atmospheric agencies as is often 
 stated, but far more probably by hydrofluoric acid brought up 
 by deep-seated fissures. That the decomposition was due to the 
 veins or fissures seems evident from the fact that the altered rock 
 occurs in bands adjacent and parallel to them. Where the 
 veins are numerous a very large mass of china clay may be found, 
 extending for a width of a hundred or more yards, and a length 
 of a quarter of a mile or half a mile along their strike ; the depth 
 to which the alteration of the granite continues is quite unknown. 
 The veins are often tin-bearing, and workings for tin have led to 
 the discovery of china clay; indeed the two minerals may be 
 worked together. The altered granite consists of quartz, white 
 mica, sometimes a little gilbertite, and felspar which has been 
 more or less completely converted into kaolin. This last mineral 
 is easily separated when the soft rock is washed down by a 
 current of water, for it is so finely divided that it is the last to 
 settle when the milky stream is led into depositing pits. 
 
 Cobalt. The cobalt ore worked at Skutterud in Norway is 
 found in certain bands of quartz 
 schist and mica schist which 
 contain small particles of cobalt 
 glance, skutterudite, cobalti- 
 ferous mispickel, ordinary mis- 
 pickel, iron pyrites, and other 
 metallic sulphides. 
 
 The accompanying figure (18) 
 illustrates what I saw at Skut- 
 terud some years ago ; a, a, , 
 are bands of mica schist with 
 little or no cobalt ore ; 5, b, are 
 bands of quartz schist containing 
 the cobaltic minerals dissemi- 
 nated through them, and c, a cobaltiferous band of mixed quartz 
 schist and mica schist. 
 
 The rocks appear to be altered sedimentary strata, and the 
 deposits must be spoken of as beds. The strike is N. and S., and 
 the beds dip at a very high angle to the east. Quartz schist is 
 the rock most likely to be cobaltiferous, the mica schist may be 
 also worth working, but hornblende schist is poor. The cobaltic 
 beds are commonly two or three fathoms wide, but a number of 
 
 * J. H. Collins, The Hensbarrow Granite District. Truro, 1878. And, 
 "On the Nauire and Origin of Clays: the Compose ion of Kaoliuite," 
 Min. May. London, vol. vii. ( 1^87), p. 205. 
 
28 
 
 ORE AND STONE-MINING. 
 
 adjacent beds may produce a much greater thickness of cobalt- 
 iferous rock. 
 
 In New Caledonia* the mode of occurrence is totally different. 
 
 FIG. 19. 
 a a .hww<i rein of Chromic Iron 
 
 of fragm enis of Chromic Iron, 
 derived, from, the Veins 
 
 The cobalt is found as a hydrated oxide, without a trace of 
 sulphur or arsenic, intimately associated with hydrated oxide of 
 manganese, in irregular " pockets " of red clay in serpentine. In 
 Fig. 1 9 S is the serpentine and A the red clay ; a a represent 
 veins of chromic iron in the serpentine ; a' a' is a little stratum 
 of fragments of chromic iron derived from these veins, whilst b b 
 are beds of cobaltiferous manganese ore in the clay. The ore 
 lying about on the surface or obtained from these pockets has from 
 2 J to 3 per cent, of cobalt. 
 
 At Khyl, in Flintshire,f there is a curious irregular cavity in 
 
 FIG. 20. 
 
 
 HORIZONTAL SCALE 
 
 3 ? 00 4 f 5 . OQO e 
 
 VERTICAL SCALE THREE TIMES THAT OF THE HORIZONTAL SCALE 
 
 the Mountain Limestone filled up with red clay which encloses 
 small lumps of asbolane. This deposit was worked on a small 
 scale for several years. 
 
 Copper. The most important copper mines of the world 
 
 * Levat, " Me moire sur les progres de la metallurgie du nickel." Ann* 
 Jlline*, ge serie, vol. i. p. 147. 
 
 f 'Irans. R. Cornwall Gcol. 8oc. t vol. x. p. 107. 
 
MODE OF OCCURRENCE OF MINERALS. 29 
 
 nowadays are those of Mansfeld in Germany, Rio Tinto and 
 Tharsis in Spain, San Domingos in Portugal, Lake Superior, 
 Arizona and Montana in the United States. 
 
 Germany. Copper mining has been carried on near Mansfeld, in 
 the Prussian province of Saxony, since the commencement of the 
 twelfth century, and the district is specially interesting from the 
 fact that the ore is found in a bed or seam, which can be worked with 
 profit in spite of its thinness and comparative poverty in metal. 
 
 The Mansfeld district (Figs. 20 and 21) is mainly occupied by 
 the rocks of the following formations : 
 
 Trias . . . . '3- Bunter Sandstone. 
 -p . j 2. Zechstein. 
 
 Permian . . . . . | ^ Rothliegendes . 
 
 (1) " Das Rothliegende," or the red floor, is the old miners' 
 name for the sandstone and breccias lying almost immediately 
 below the bed of cupriferous shale. In contradistinction to the 
 ore-bed, it is also called " das Todtliegende " (the dead floor). It 
 can always be distinguished by its characteristic red colour. One 
 of its most constant beds is the so-called " porphyry con- 
 glomerate," consisting of pebbles of milk-white quartz, hard 
 siliceous slate, and grey and reddish porphyry, 
 
 (2) The Zechstein formation consists of three divisions. The 
 lowest division comprises the " Weissliegendes," the bed of copper 
 shale and the Zechstein. The middle division consists of the 
 anhydrite or older gypsum, or of its equivalent the " Rauchwacke," 
 " Asche," " Rauhstein " and Stinkstone ; the upper division is 
 made up of variegated clays with intercalations of gypsum, the 
 residues left when some of it is dissolved away (Asche), and cal- 
 careous or dolomitic concretions.* 
 
 The " Weissliegendes" is petrographically like the " Rothlie- 
 gendes " below it, and is looked upon by many as merely an 
 uppermost bed deprived of colour. Above it with great 
 regularity comes the ore bed, a blackish, bituminous, marly shale, 
 about 15 to 1 8 inches thick. 
 
 The ore of the shale bed is usually disseminated through it in 
 the form of fine particles (Speise), which impart a metallic glitter 
 to the surface of cross-fractures. A golden yellow colour indicates 
 chalcopyrite, a bluish and reddish variegated look, bornite, and a 
 steel grey, seen more rarely, is due to copper glance ; whilst a 
 greyish yellow denotes a predominance of iron pyrites, and a 
 leaden grey, galena. The following minerals also occur : cinnabar, 
 blende, kupfernickel, speiskobalt, and compounds of manganese, 
 molybdenum and selenium. Oxidised ores are found at the outcropj 
 
 * The figures and some of the details concerning the Mansfeld mines are 
 borrowed from a pamphlet entitled " Der Kupferschieferbergbau und der 
 Hiittenbetrieb zur Verarbeitung der gewonnenen Minern in den beiden 
 Mansfelder Kreisen der Preussischen Provinz Sachsen." Eisleben, 1889. 
 
ORE AND STONE-MINING. 
 
 and are naturally of secondary origin. In addition to the finely 
 disseminated grains, there are often small strings of bornite and 
 copper glance, generally parallel to the bedding, and thin coatings 
 of copper glance, bornite, chalcopyrite, and native silver along the 
 
 FIG. 21. 
 SECTION OP EDUARD II. SHAFT. 
 
 Soil . 
 
 Bunter Sandstone . 
 
 Gypsum 
 
 Stinkstone and "A scJie " 
 
 Blue Shale 
 
 Stinkstone and " A sc/ie " 
 
 Gypsum . 
 
 Zechstein 
 
 Copper Shale . . . , . A * 
 Rothliegendes . . . . . ^ 
 
 Conglomerate 
 Rothliegendes 
 
 Rothliegendes ivith Melapliyre 
 
 Rothliegendes 
 
 planes of bedding or in cross joints. Finally there may be small 
 nodules of copper ore lying singly. 
 
 The whole of the bed of copper shale is ore-bearing ; but, as a 
 rule, only the bottom 3 or 4 inches are rich enough to be worked 
 with profit. Occasionally 6 or 7 inches can be taken, and in ex- 
 ceptional cases the whole of the bed goes to the smelting works. 
 
 Although there are minor variations, the shale is fairly regular 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 3 1 
 
 as regards ore-bearing when dealt with on a large scale. On an 
 average, in the true Mansfeld district, between Gerbstedt and 
 Eisleben, it contains 2 to 3 per cent, of copper and 163 oz. of 
 silver to the ton of copper (5 kil. per metric ton). 
 
 The importance of the copper shale will be appreciated from 
 the fact that in the year 1888, 14,178 persons were employed at 
 the mines, or more than all the miners of Cornwall and Devon. 
 The output of ore was 469,716 metric tons, which produced 
 13,600 metric tons of refined copper, and 77,950 kilogrammes 
 (208,845 Troy pounds) of silver. 
 
 Spain and Portugal. The famous mines of Rio Tinto,* 
 
 FIG. 22. 
 
 Tharsis, and San Domingos are contained in a great metalliferous 
 belt of country, 140 miles long by 30 miles wide, stretching 
 across the province of Huelva in Spain and into Portugal. The 
 rocks consist of slate of Upper Devonian age, often altered 
 locally into jasper, talc schist, chiastolite schist, etc., with great 
 intrusions of quartz and felspar-porphyries, diabase, quartz- 
 syenite, and granite. The geological horizon of the slate has been 
 determined by finding Posidonomya JBecheri, P. acuticosta, a 
 goniatite allied to G. subsulccutus and other fossils. The strike of 
 the slates is about 15 to 25 north of west, and the dip either 
 
 * Collins, "On the Geology of the Rio Tinto Mines, with some General 
 Remarks on the Pyritic Region of the Sierra Morena," Quart. Journ. Geal. 
 &*;., vol. xli. (1885), p. 245. 
 
ORE AND STONE-MINING. 
 
 vertical or at a high angle to the north. Through having the same 
 general strike as the slate, the masses of porphyry may appear to 
 be interstratified, but a close examination of the junction proves 
 them to be intrusive. 
 
 As shown by the map (Fig. 22), there are four principal 
 
 deposits of pyrites at Rio 
 
 FlG - 23- Tinto, viz., the North 
 
 Lode, the South Lode, 
 ^;-',-. the San Dionisio Lode, 
 CVX-J and the Valley Lode. 
 V^'// They all occur at or 
 near the junction of the 
 porphyry and the slate ; 
 and they are supposed by 
 Mr. Collins to occupy 
 cavities produced by fis- 
 sures. On the other hand, 
 the somewhat similar 
 deposit of the Rammels- 
 berg mine in the Hartz 
 is now unanimously con- 
 sidered by geologists to 
 be of sedimentary origin, 
 and to be strictly con- 
 formable to the surround- 
 ing beds of slate. 
 
 The South Lode, the 
 one most largely wrought 
 hitherto, is sometimes as 
 much as 450 feet (140 m.) 
 wide, and is known along 
 the strike for a distance 
 of about a mile, or, in- 
 deed, for two miles if the 
 San Dionisio lode is con- 
 sidered to be an extension 
 of it to the west. Fig. 
 23 is a cross-section of 
 the South Lode at San 
 Inocente shaft, and Figs. 24, 25, and 26 are taken at points a 
 little to the east, 
 
 INDEX FOR FIGS. 23 TO 25. 
 
 Porphyry. 
 
 Porphyry worked 
 away. 
 
 Slate 
 
 Slate worked 
 away. 
 
 Pyrites. 
 
 Pyrites worked 
 away. 
 
 Ferruginous breccia and gozzan. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 33 
 
 Figures* 27 and 28 show the curious manner in which the San 
 Pinnisio lode swells out suddenly at a depth of about 150 metres 
 from the surface, and actually attains the enormous width of 200 
 metres. A, is slate ; B, porphyry ; C, cupreous pyrites ; D, iron 
 ore, the " gozzan " or iron cap of the lode. The slate is dipping 
 steeply towards the lode, as indicated by the lines denoting planes 
 of bedding. The hatching of C itself does not represent any 
 structure. It will be interesting geologically and important 
 commercially to watch the further development of the workings 
 upon this remarkable lode. 
 
 The character of the ore varies a good deal. Mr. Collins 
 names fourteen different kinds. The principal are : (i) Ore 
 treated for copper on the spot, and (2) that which is exported. 
 The former consists of fine-grained and compact iron pyrites 
 with i to 2 1 per cent, of copper, existing as copper-pyrites 
 minutely disseminated throughout the mass, and the latter only 
 differs by being richer in copper, and containing up to 3! per 
 cent. 
 
 Little veins of copper- pyrites, erubescite, and occasionally 
 copper-glance, more or less 
 
 mixed with iron - pyrites, FIG. 27. 
 
 quartz, blende, and other 
 minerals, traverse the mass, 
 and there is sometimes a 
 compact mixture of galena, 
 blende, chalcopyrite, and 
 iron-pyrites resembling the 
 " bluestone " of Anglesey. 
 
 Few mines in the world 
 are of more importance 
 than Rio Tinto. The quan- 
 tity of ore extracted in 
 1892! was 1,402,063 tons of 
 21 cwt., of which 995,151 
 tons were for local treat- 
 ment and 406,912 for shipment to Great Britain, Germany, 
 and the United States. The average percentage of copper was 
 2*819. 
 
 The deposits of iron ore marked on the map are horizontal 
 beds, probably formed at the bottom of lakes in Miocene times. 
 The ore is brown haematite, with varying proportions of silica. 
 The sections show that the upper part of the pyrites has been 
 converted into a gozzan ; much of this is a good iron ore, and is 
 being stocked for disposal at some future time. 
 
 y Mr - James 
 
 t Rio Tiuto Co. Ltd., Twentieth Annual Report, April 1893. 
 
34 OEE AND STONE-MINING. 
 
 The Tharsis and San. Domingos mines are likewise vast under- 
 takings, and the total imports of cupreous iron-pyrites into this 
 country alone from Spain and Portugal in 1891 amounted to 
 608,000 tons, worth over one million sterling.* 
 
 FIG. 28. 
 
 SCALE 
 
 o 200 400 600 800 feet 
 
 United States. Crossing the Atlantic, we will now turn our 
 attention to the mines on the southern shore of Lake Superior, 
 which are remarkable for their productiveness, and which are 
 equally attractive to the geologist and to the miner. 
 
 The copper-bearing districtf lies on a long peninsula, 15 to 20 
 miles wide, with a north-easterly trend, which projects into Lake 
 Superior (Fig. 29 J) some 60 miles beyond the general run of 
 its southern shore, and terminates in Keweenaw Point. The 
 western half of the peninsula is formed by rocks belonging to the 
 Keweenaw Series, considered by many to be younger than the 
 Huronian and older than the Cambrian. They consist of sand- 
 stones and conglomerates, inter stratified with flows of eruptive 
 rocks of various kinds. 
 
 The beds dip to the north-west, at an angle of 22 in the 
 northern parf of the mineral district, and in going south the 
 dip increases to 56. The outcrop of the actual copper-bearing 
 part of the series occupies a belt of country from 4 to 5 miles 
 wide. 
 
 * Min. Stat. for 1891. London, 1892, p. 59. 
 
 f E. D. Irving, " The Copper-bearing Eocks of Lake Superior," United 
 States Gt ol. Survey. Washington, 1883. Douglas, " The Cof per Et-sourees 
 of the United States," Trans. Amer. Inst. M.E., \ol. xix. 1890, p. 679; 
 and Jour. Soc. Arts, vol. xli. 1892, p. 39. 
 
 J Engineering, vol. 1. 1890, p. 553; and Guide-book prepared for the 
 members of the Iron and Steel Institute, 1890. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 35 
 
 The modes of occurrence of the copper may be classified as 
 follows : 
 
 A BEDS / T * Copper-bearing conglomerate and sandstone. 
 
 (2. Copper-beaiing amygdaloid. 
 B. VEINS. 
 
 A. (i) The deposits of the first class are beds of conglomerate 
 and sandstone impregnated with native copper. In most cases 
 the cupriferous beds are iriterstratified v-'ith diabase flows; but 
 
 FIG. 29. 
 
 REDJACKET 
 
 AAMAKACK 
 
 South Heel 
 Osceola 
 
 this connection between the proximity of diabase and the presence 
 of copper is not universal. The copper occurs as the cementing 
 material of the pebbles and grains of sand, and also replaces the 
 pebbles themselves, large stones several inches or even a foot in 
 diameter being converted into the native metal. The copper has 
 evidently been deposited from aqueous solutions. By far the 
 greatest proportion of the Lake Superior copper is obtained from 
 these conglomerates. 
 
 A. (2) The cupriferous amygdaloids are portions of the old lava 
 flows, and are not strictly speaking beds as defined, though it is 
 convenient to call them by that name. 
 
 Often they are highly altered and have lost all sign of having 
 
ORE AND STONE-MINING. 
 
 once been vesicular; the native copper which they contain must 
 have found its way in long after their eruption.* It is usually 
 very irregularly distributed, and the parts rich enough to be 
 worked may be surrounded by much poor or barren rock. The 
 presence of epidote and calcite is regarded as a good indication 
 for the proximity of copper. 
 
 B. As the cupriferous lava beds and conglomerates are locally 
 called "veins," it is necessary to say that the real veins run in 
 a direction at right angles to the general trend of the beds, and 
 are almost vertical. Their usual width is from one to three 
 feet, but it may become as much as 10, 20, and even 30 feet. 
 They are largest and richest when they have amygdaloid or loose- 
 textured diabase for their walls, and they become pinched up and 
 worthless in the compact greenstone or sandstone. To a great 
 extent they consist of altered rock, and are an instance of lodes 
 formed by replacement of the " country." According to Irving 
 these veins were formed by copper-bearing solutions which found 
 a path through zones of fissured rock, instead of following certain 
 easily permeable beds. The copper is in the native state, and 
 generally in masses of considerable size, the largest found weigh- 
 ing nearly 600 tons. 
 
 The following statistics relating to the Lake Superior mines 
 are taken from a guide-book prepared for the members of the 
 Iron and Steel Institute in 1890. 
 
 Name of Mine. 
 
 Nature of 
 deposit. 
 
 Depth 
 in feet. 
 
 Tons rock 
 
 hoisted 
 1889. 
 
 Tons 
 Refined 
 Copper 
 1889. 
 
 Tons 
 Copper 
 to date. 
 
 Per cent 
 copper 
 in rock 
 stamped. 
 
 Dividends 
 to date. 
 
 Dollars. 
 
 Allouez . . 
 
 Conglo- 
 
 1700 
 
 126,125 
 
 881 
 
 11,427 
 
 '76 
 
 
 
 merate 
 
 
 
 
 
 
 
 Calumet and 
 
 
 
 
 
 
 
 
 Hecla . . 
 
 M 
 
 375 
 
 807,918 
 
 24.334 
 
 301,538 
 
 3-01 
 
 33,350,000 
 
 Peninsula . 
 
 }> 
 
 600 
 
 
 
 368 
 
 
 
 
 Tamarack . 
 
 5 
 
 2818 1 196,707 
 
 5.5i8 
 
 16,624 
 
 3^6 
 
 1,200,000 
 
 Atlantic . . 
 
 Amygda- 
 
 1660 
 
 288,040 
 
 1,849 
 
 23,786 
 
 0-66 
 
 560,000 
 
 
 loid 
 
 
 
 
 
 
 
 Copper Falls 
 
 
 1500 
 
 I 435 
 
 10,789 
 
 0*70 
 
 100,000 
 
 Franklin 
 
 M 
 
 2620 
 
 186,740 
 
 2,173 
 
 31,961 
 
 1-87 
 
 960,000 
 
 Huron . . 
 
 H 
 
 1800 
 
 159.333 
 
 1,109 
 
 10,652 
 
 0*98 
 
 
 Kearsarge . 
 
 
 
 IOOO 
 
 76,541 
 
 960 
 
 1.384 
 
 171 
 
 80,000 
 
 Osceola . . 
 
 
 
 2162 
 
 208,299 
 
 2,631 25,312 
 
 1-29 
 
 1,222,500 
 
 Quincy . . 
 
 
 
 3070 
 
 123,998 
 
 3,203 
 
 53.250 
 
 272 
 
 5,250,000 
 
 Central . . 
 
 Veins 
 
 2900 
 
 Mostly 
 
 635 
 
 20,355 1 
 
 1,930,000 
 
 
 
 
 mass. 
 
 
 I 
 
 
 
 
 
 
 
 1 
 
 
 As will be seen from these figures, the Calumet and Hecla 
 mine is the most important on Lake Superior. The bed of 
 copper- bearing conglomerate is from 8 to 25 feet thick, and 
 
 * Irving, Op. cit. p, 421. 
 
MODE OF OCCURRENCE OF MINERALS. 37 
 
 about 12 feet on an average. The dip is 37^ to the north-west. 
 The depth of the mine which is given in the table is measured 
 on the dip, and would be about 2,280 feet if measured vertically ; 
 but these figures are now greatly exceeded, and shafts are being 
 sunk which will enable the Calumet and Hecla and the Tamarack 
 mines to be worked to the enormous depth of 5000 feet. 
 
 The very low percentage of copper in the Atlantic amygdaloid, 
 which nevertheless is worked at a profit, is remarkable ] but, 
 unlike the amygdaloids generally, the Atlantic reck is very 
 regular in its yield. This makes up for its poverty. 
 
 Arizona* produces large quantities of oxidised ores of copper, 
 especially the oxide and carbonates, wh : ch occur in or adjacent to 
 the Carboniferous limestone. Sometimes there are irregular ore- 
 bodies at the contact of the limestone with granite or with sand- 
 stone. Masses of sulphuretted ores which have escaped decay 
 show whence the oxidised ores have been derived. 
 
 The Batte district, Montana, t has surprised the world of 
 late years by the enormous quantities of copper ore which 
 it has sent into the market. The deposits are east and west 
 lodes in granite, usually dipping steeply to the south. The 
 main lode, which supports the celebrated Anaconda and Parrott 
 mines, has proved productive for a distance of three miles along 
 the strike. The principal ores are erubescite, copper glance, 
 and chalcopyrite. Everywhere near the lodes the granite is soft 
 and friable, and often contains ore- bodies. Though the granite 
 has been greatly fissured, it seems likely that much of the ore 
 does not fill up cracks, but has gradually taken the place of the 
 rock by a process of substitution. The width of the lodes varies 
 considerably; however, on an average it may be taken at ten feet. 
 The copper ore is silver-bearing, the proportion varying from J oz. 
 per unit of copper to 2 oz. per unit. 
 
 The upper parts of the veins consisted of oxidised minerals, from 
 which the copper had been leached out almost entirely, but in which 
 the silver was retained and formed the original object of the mining. 
 At the Anaconda mine there was no copper worth speaking of 
 for the first 400 feet in depth ; then came a rich zone of 
 oxisulphides and erubescite, considered to contain some of the 
 copper which had been dissolved out of the vein at a higher level, 
 and after lasting for 200 feet it was succeeded by the unaltered 
 sulphides. 
 
 Diamonds. By far the most important diamond district in 
 the world is Kimberley, in Cape Colony, 648 miles by rail from 
 Cape Town. Strange to say, most of the precious gems are 
 
 * Douglas, Op. cit. 
 
 t Douelas, Op. cit. Vore^ang, " Miftheiluneren iiber den Kupferberg- 
 bau in Nord-America," Zntschr. B.- H.~ u. S.- Wesen, vol. xxxix. 1801, 
 p. 231. G. vom Raf.h, " Ueber das Gangrevier von Butte, Montana," N. 
 Jukrb.f. Mi^r. GcA a. Paiaont., vol. i. (1885) p. 158. 
 
3 8 ORE AND STONE-MINING. 
 
 obtained from four deposits situated in close proximity to each 
 other ; indeed, all four are included in a circle three miles in 
 diameter. The masses of diamond- bearing rock may be described 
 as huge vertical columns, of round, oval, or kidney-shaped section, 
 as shown by Figs. 30 and 31.* The unweathered diamond-bearing 
 
 FIG. 30. 
 
 300 METRES 
 
 FIG. 31, 
 
 DE BEERS MINE 
 
 K/MBERLEY 
 MINE 
 
 rock, locally known as " blue ground/' or " blue," is a breccia, 
 consisting of fragments of shale, basalt, diorite, and a little 
 sandstone, cemented together by olivine rock containing diamonds 
 and various other minerals, such as bronzite, biotite, talc, 
 garnet, graphite, magnetite, and iron 
 pyrites. The surrounding rocks, locally 
 called " reef," are beds of carbonaceous 
 and pyritiferous shale lying horizontally, 
 and sheets of basalt and melaphyre, 
 under which comes quartzite. The mela- 
 phyre is a hard amygdaloidal rock, 
 which has also been called olivine dia- 
 base, t Large detached masses of the 
 surrounding rocks are sometimes in- 
 cluded in the "blue," and are then 
 known as " floating reef." The upper 
 parts of the deposits have been decom- 
 posed by atmospheric agencies, and changed into a soft friable 
 earth to a depth varying from 45 to 60 feet, and the colour is 
 yellow, instead of the slaty blue of the unweathered rock. The 
 surrounding rocks have naturally shared in this weathering. 
 
 * De Beers Consolidated Mines, Limited, Second Annual Eeport, 1890, 
 including a technical report with plates. 
 f Ibid. p. 13. 
 
 DU TOITSPAM 
 MINE 
 
 BULTFONTEM^Q 
 MINE 
 
MODE OF OCCURRENCE OF MINERALS. 39 
 
 The diamond-bearing rock appears to be the filling-up of the 
 necks or throats of old volcanoes by a mud from below. From 
 tr e frequent occurrence of broken diamonds it is fairly inferred 
 that the gems were not formed in situ,, but were carried up 
 with the " blue." 
 
 Not only does the yield in diamonds vary in the different mines, 
 but the diamonds themselves have their peculiar characteristics, 
 which enable the expert to say at once from which mine a stone 
 has been obtained. The average yield of the "blue ground" 
 per load of 16 cubic feet * is as follows : 
 
 Val ue per carat 
 Area. Carats per load. in 1889. 
 
 Bultfontein . . . i to . . i 7 7 
 
 De Beers . . . . i to i . . . 176 
 
 Du Ton's Pan . . to i . i 19 10^ 
 
 Kimberley . . . i to i . . . . I 7 9i . 
 
 In addition to these four mines there are some other workings 
 in the neighbourhood, such as Wesselton and St. Augustine ; 
 whilst at Jagersfontein, 80 miles to the south in the Orange Free 
 State, there is a similar deposit, producing stones of the finest 
 water. 
 
 The commercial importance of the diamond deposits cannot be 
 overestimated, for the value of the diamonds produced annually 
 at Kimberley is between three and four millions sterling, or more 
 than the value of the gold produced by any one of the British 
 colonies.f 
 
 Until lately, the largest diamond found weighed 42 8 J carats 
 in the rough state, and 228^ carats after cutting ; it came from 
 De Beers mine. This large stone has been eclipsed by one of 969^ 
 carats discovered at Jagersfontein in the month of June last. 
 
 In addition to diamonds found in a solid matrix, there are 
 those from the river diggings. It was in the recent alluvium 
 of the Vaal River that diamonds were first discovered in 1867, 
 and though thrown into the shade by the output of the mines, 
 the gravel is still washed by parties of men scattered along the 
 banks of the river for a distance of 70 miles. 
 
 Diamonds are found in alluvial gravel and in conglomerate in 
 Brazil, India, and other localities. 
 
 Flint. It may be thought strange by some that I give flint a 
 
 * Sixteen cubic feet of broken ground correspond to about 9 cubic feet 
 of solid ground. 
 
 t Further information about the Kimberley diamond mines will be found 
 in the following publications: T. Reunert, "Diamond Mining at the 
 Cape," History, Productions, and Resources of the Cape of Good Hope. Cape 
 Town, 1886. C. Le Neve Foster, " Mining Industries," Reports on the 
 Colonial and Indian Exhibition. London, 1887. E. Boutan, " Sur 1'etat 
 aciuel des mines de diamants du Ca,p," Genie Civil. Paris, January 26, 
 1089. 
 
ORE AND STONE-MINING. 
 
 place among the important minerals which deserve special de- 
 scription. My reasons for mentioning it are twofold. First, the 
 
 FIG. 32. 
 
 Sand and Gravel 
 
 Dead Lime 
 
 Soft White Chalk 
 
 Horns Flint 
 Soft White Chalk 
 Topping Flint . 
 
 Soft White Chalk 
 
 First Pipeclay . 
 Hard-White Chalk 
 Ufrfter Crust Flint 
 .' oft White Chalk 
 Second Pipeclay . 
 hard Chalk 
 
 Soft White Chalk 
 Wall Stone 
 
 Soft Chalk with ffon 
 
 Soft White Chalk 
 Third Pipeclay . 
 
 Hard Chalk 
 
 Floor Stone . 
 
 Soft White Chalk . . 
 
 Hard Chalk . . x. 
 
 Rough and Smooth Blacks. S3. 
 
 Soft White Chalk 
 
 
 .- H 
 
 VI) '//___ r- 
 
 1* -L 
 
 j3 
 
 earliest underground workings in this country were prrbably for 
 flint ; and secondly, flint affords a good instance of the replace- 
 ment of an original bed by another mineral. 
 
MODE OF OCCURRENCE OF MINERALS. 41 
 
 Pits in the chalk known as " Grime's graves,"* were at one 
 time a puzzle to the antiquary, but it is now generally conceded 
 that they are the mine shafts by which beds of flints were worked 
 for the manufacture of stone implements in Neolithic times. 
 
 This old trade of flint mining still survives at Brandon in 
 Suffolk, for though stone hatchets and arrow-heads are no longer 
 wanted, there is still a market for gun -flints in parts of Africa. The 
 mode of mining the stone, splitting off flakes and knapping them 
 into gun-flints has been admirably described and illustrated by 
 Mr. Skertchlyf in one of the " Memoirs of the Geological Survey 
 of England and Wales." Fig. 32 represents a section of the beds 
 in which the flint occurs. It shows that the layers of flint are 
 sometimes continuous, and sometimes consist merely of a succession 
 of nodules which do not touch each other. Some of the flint has 
 knobs and even horn-like projections, the transformation from 
 chalk into silica not being confined strictly to one particular layer 
 of the original sea-bottom. The principal bed is the " floor-stone," 
 No. 20, about 8 inches thick, but other layers are mined from 
 time to time for building stone or gun-flints. J 
 
 Freestone. Freestone is largely quarried in England from 
 beds of Jurassic age, and the so-called " Bath stone " is not only 
 quarried but also mined at Corsham in Somersetshire, and at 
 Weldon in Northamptonshire. The bed worked in the Corsham 
 underground quarries varies from 8 to 24 feet in thickness, lying 
 almost flat ; it is a typical oolitic limestone which can be sawn 
 freely in any direction. 
 
 Gold. This metal is so widely distributed over the earth that 
 it will be impossible to compress into the space at my disposal 
 anything more than a very summary description of the principal 
 modes of occurrence in beds, veins, and masses. 
 
 Beds. During the last few years the attention of cap- 
 italists, miners, and geologists has been often directed to the 
 marvellous resources of the Witwatersrand|| or simply " Rand " 
 goldfield, in the Transvaal or South African Republic, and 
 situated about 35 miles south of Pretoria, the capital. The gold 
 is obtained entirely from beds of conglomerate or puddingstoiie 
 called banket, which is the Dutch name for almond rock, the 
 hardbake of the British schoolboy, because the pebbles look like 
 
 * The word " grave " no doubt corresj onds here to the German Graben, 
 a ditch or trench, and has no reference to burial. 
 
 f On the Manufacture of Gun-Flints, &c. London, 1879. 
 
 + A more or let-s regular and continuous layer of flints is locally called a 
 sase or sf-se, which recalls the French word " assise." 
 
 C. Le Neve Foster, " Some Mining Notes in 1887," Trans. Min. Assoc. 
 and Inst. Cornwall, vol. ii. p. 136. Camborne, 1888. 
 
 || A very complete summary of papers upon South African Geology is 
 given by Mr. Gibson in his memoir, " The Geology of the Gold-bearing and 
 Associated Rocks of the Southern T.ansvaal," Quart. Jour. Geol. Soc., 
 vol. xlviii. (1892), p. 406. 
 
ORE AND STONE-MINING. 
 
 f-- 5 
 
 ^S Qt-S 
 
 o> VS "S 
 .s ">^ ' 
 
 -^^r : 
 
 >l 
 
 
 K^* 
 
 bC 
 
 Sco^^ 
 
 ^5 |f 
 
 M a &o 
 
 the almonds in the sugar. The 
 layers of auriferous conglomerate 
 lie conformably among beds of 
 sandstone, shale, clay, and quarfczite. 
 At Johannesburg the beds strike 
 east and west and dip to the south. 
 The conglomerate consists mainly 
 of pebbles of white quartz, and in 
 the upper parts of the workings 
 they are cemented together by oxide 
 of iron, sand, and clay. Below the 
 influence of atmospheric agencies, 
 the cementing material is found to 
 consist largely of silvery-grey mi- 
 caceous matter with cubical crystals 
 of iron pyrites, and the colour of 
 the banket changes from red and 
 brown to blue and bluish grey. It 
 is quite evident from the examina- 
 tion of spscimens that much of the 
 ferruginous matter in the upper 
 parts of the conglomerate is derived 
 from the decomposition of iron 
 pyrites, and visible gold is seen in 
 the cavities formerly occupied by 
 crystals of that mineral. The bulk 
 of the gold is said to exist in the 
 cement and not in the pebbles ; but 
 some assays made by the late Mr. 
 Richard Smith show that this is not 
 invariably the case. 
 
 Fig. 33,* a section across the 
 Salisbury Mine at Johannesburg, 
 shows four beds of auriferous con- 
 glomerate, known respectively as 
 the North Rpef , the Main Reef, the 
 Main Reef Leader, and the South 
 Reef. 
 
 As would naturally be expected 
 in the case of beds which must have 
 been deposited in shallow water, 
 there are frequent variations of 
 character and thickness in a short 
 distance. 
 
 Whilst certain beds of conglome- 
 rate are auriferous, others are not, 
 
 * Gibson, Ibid. p. 411. 
 
MODE OF OCCURRENCE OF MINERALS. 43 
 
 or contain merely traces of gold. The sandstone, as a rule, is 
 not auriferous, but layers within the banket may be worth 
 working. The richest beds are the Main and South Reef with 
 some of the thin " leaders." The gold is not distributed 
 uniformly through the bed of banket ; but upon the whole there 
 ib f ar greater regularity of yield than can be expected in a vein, 
 and as a rule the whole of the bed is worked away like a seam of 
 coal, without poor portions being left. The fact of being able to 
 form a rough approximate estimate of the probable yield of a 
 given area of banket is of the utmost commercial importance. 
 
 The Rand output in 1892* was 1,210,865 ounces of bar gold ; 
 the average total yield of the conglomerate stamped was 12 J dwt. 
 of gold per ton, of which about four-fifths were obtained at once 
 by amalgamation at the mills, and one-fifth by subsequent treat- 
 ment of the tailings and concentrates. 
 
 The gold-bearing strata are supposed to be of Devonian age. 
 
 Whether the gold was deposited at the same time as the 
 pebbles of quartz, or whether it was brought by the subsequent 
 
 FIG. 34. 
 
 SCALE, or rctr 
 
 a, hard grey siliceous shale ; &, massive quartzite, becoming 
 talcose and highly auriferous in zones ; c, schistose quartzite, 
 becoming argillaceous in places ; d, impure sandstone quartzite, 
 e, quartzose breccia wiih fragments of felsite and clay shale ; f t 
 hard grey siliceous shale ; </, highly auriferous sandy matter 
 resulting from the disintegration of the bed &. 
 
 infiltration of mineral solutions which found their easiest 
 channels of escape through the most readily permeable beds, lias 
 net been decided; but where the bulk of a deposit consists of 
 
 * Phillips, " Address to the Rand Chamber of Mines," January 20th 
 1893. 
 
44 
 
 ORE AND STONE-MINING. 
 
 materials of undoubted sedimentary origin, it is best for the 
 miner to call it a " bed " or " seam," and leave the question of 
 origin to be settled later on by the geologist. 
 
 Fig. 34 represents a section of the Sheba mine, Barberton,* 
 where the gold is obtained from a bed of auriferous quartzite. 
 
 Fig. 35 is a section of an auriferous alluvium in the Caratal 
 district of Venezuela.! 
 
 FIG. 35. 
 
 The following is the succession of the beds : r. Soil. 2. Hod 
 clay, showing no signs of stratification. 3. Soft clavey " moco de 
 hierro." 4. Hard brown iron ore ("moco de hierro"), wilh 
 pieces of quartz in it and a little clay. 5. Blocks of vein-quartz, 
 often auriferous. 6. " Greda," or pjiy-dirt, a yellow ferr ginous 
 clay containing nuggets and small grains of gold. 7. " Cas^ajo," 
 decomposed schist, lormmg the "bed-rock." 
 
 Fig. 36 explains how a superficial gold-benring "rainwash" 
 may result from the denudation of a bed of auriferous gravel. 
 
 Some of the deposits of gold in Brazil occur under totally 
 different conditions. The precious metal is found in beds of 
 jacotinga, the local name for a friable mixture of micaceous iron 
 earthy brown iron ore, oxide of manganese, lithomarge or talc, a 
 little quartz, and small lumps and granules of gold. The beds of 
 jacotinga occur as subordinate bands in the rock known as 
 itabirite, composed mainly of micaceous iron, specular iron, mag- 
 
 * MS. of C. J. Alford, F.G.S. 
 
 t C. Le Neve Footer, " On the Caratal Gold-field," Quart. Jour. Geol. 
 &>c., vol. xxv. 1869, p. 340. 
 
MODE OF OCCURRENCE OF MINERALS. 45 
 
 netite, and granular quartz. Some of the beds of itabirite ;>rd 
 worked as iron ores. 
 
 FIG. 36. 
 
 i. Schist ("Cascajo") or felstone forming the bed-rock of a fer- 
 ruginous gold-bearing gravel (" moco de hierro ") 2 ; 3. Ked fer- 
 ruginous earth ("Tierra de flor ") containing nuggets of gold. 
 
 Though the jacotinga forms beds, the gold is not uniformly dis- 
 tributed through it, but is concentrated in productive shoots. 
 
 Veins. The veins usually consist in great part of quartz, and 
 contain in addition iron pyrites, or some other heavy metallic sul- 
 phides, such as galena, zinc blende, copper pyrites, magnetic pyrites, 
 stibnite and mispickel. The gold is principally in the metallic 
 state, even when enveloped in pyrites, which is so frequently the 
 case ; but it occurs also in combination with tellurium, and with 
 bismuth. 
 
 The " Great Quartz Yein," or " Mother Lode," in the Sierra 
 Nevada of California is the first deposit that must be noticed ; 
 for it is remarkable by its length, its width, the number of 
 mines which are dependent upon it, and their annual yield of 
 the precious metal. Some of the most important facts concerning 
 it have been described by Whitney.* The axis of the Sierra 
 Nevada is a mass of intrusive granite, which is flanked by meta- 
 morphic Triassic and Jurassic rocks ; the existence of fossils proves 
 the gold-bearing strata to be of Secondary age. The rocks in 
 which the principal gold veins of this region occur, are slates 
 of various kinds, such as clay-slate, talcose slate and chloritic 
 slate, which form a marked belt, sometimes 18 miles wide, running 
 through the country for fully 150 miles. The slates are accom- 
 panied by a band of serpentine sometimes a mile wide. "Asso- 
 ciated with the serpentine is the very remarkable mass of quartz 
 known as the ' Great Quartz Vein,' which may be traced for a 
 distance of 80 miles from Amador County to Mariposa County in 
 a general S.E. by S. direction. "f "This powerful lode is made 
 up of irregularly parallel plates of white compact quartz and 
 crystalline dolomite or magnesite,* more or less mixed with 
 
 * The Auriferous Gravels of the Sierra Nevada of California. Cambridge, 
 U.S., 1880, p. 45. 
 
 t Op. cit. p. 46. 
 
 Whitney adds the note " In the only specimen which has thus far 
 been chemically examined, the supposed dolomivic portion proved to be 
 an intimate mixture of quartz ana magnetite." 
 
4 6 
 
 ORE AND STONE-MINING. 
 
 green talc; and these plates, which somewhat resemble the 
 * combs ' of ordinary lodes, are either in contact or separated from 
 each other by intercalated layers of talcose slate." " The quartz 
 is the auriferous portion of the lode, although it is far from being 
 uniformly impregnated with gold." " The talcose slate bands in 
 the vein are often themselves more or less auriferous." In one 
 place the vein is 261 feet wide measured horizontally across it, 
 and it dips to the north-east at an angle of 60. Whitney says 
 it is not proved to be a fissure vein, and he is more inclined to 
 consider it as a metamorphosed belt of rock. 
 
 The map of the lode given by Collins,* shows seventy-seven 
 mines which are now being worked, or which have been profitably 
 worked in recent times, and we learn from him that the auri- 
 ferous quartz contains small quantities of metallic sulphides, such 
 as iron pyrites, mispickel, marcasite, chalcopyrite, and galena. 
 The quantity of gold produced from the quartz treated varies from 
 3 dwts. to 15 or 20 dwts. per ton, and the " Great Quartz Vein" 
 or " Mother Lode " is estimated to yield about two million dollars 
 worth of gold annually. 
 
 The gold veins, or " reefs," in Victoria are found in the Upper 
 and Lower Silurian rocks. The gold is especially associated with 
 
 FIG. 37. 
 
 r'-^F^i SLATE 
 
 SADDLE. 
 
 ^I QUARTZ. 
 
 iron pyrites ; when it decomposes a cellular honeycombed quartz 
 is left behind, and the gold is unmasked and rendered visible 
 in the little rusty cavities. Other heavy metallic sulphides are 
 common here as elsewhere. 
 
 The peculiarities of the so-called "saddle-reefs" of the Sand- 
 
 * " Notes on the Great Mother Lode of California," Jour. Hoy. List. 
 Cornwall. Truro. Vol. ix. (1886), p. 64. 
 
MODE OF OCCURRENCE OF MINERALS. 47 
 
 hurst or Bendigo gold-field, Victoria, which differ considerably 
 from typical veins, have been very clearly explained by Mr. T. 
 A. Rickard,* from whose useful memoir the following account is 
 borrowed. These reefs are arch-like masses of quartz conform- 
 able to the bedding of the surrounding Lower Silurian slate and 
 sandstone, as shown by the letters BACin Fig. 37. The part 
 A is called the " cap" or " apex "; B is the " west leg " and C the 
 " east leg," because the main anticlinal axes strike N.N.W. and 
 S.S.E. The part D is known as the " centre country," the rocks 
 to the east of form the " east country," and those to the west 
 of B the " west country." The inclination of the line of the 
 ridge, northwards or southwards, is 
 spoken of as the " pitch," in order to FIG. 38. 
 
 distinguish it from the dip of the 
 strata. There may be more than one 
 such saddle, or a long succession of 
 them, one below the other (Fig. 38), 
 but they are not all equally auriferous. 
 Thus, out of five which have been 
 discovered and explored at " 180" 
 mine, only three have proved to be 
 worth working for gold. 
 
 Similar masses of auriferous quartz 
 have been found at some of the 
 synclines ("inverted saddles"), and 
 worked to a slight extent. Very 
 large dividends have been paid by 
 many of the companies working the 
 " saddle-reefs." 
 
 Masses. Having given examples 
 of auriferous beds and veins, I come 
 to masses. Tread well mine,t situated SADDLES 
 
 on Douglas island, Alaska, owes its 
 
 existence to a mass of auriferous altered granite, 400 feet wide 
 and of considerable length. The rock, which appears to have 
 been a hornblende granite originally, now consists principally of 
 quartz and felspar, with a little calcite and specks of iron pyrites, 
 and it is traversed by strings of quartz, iron pyrites, and calcite. 
 The original rock was probably crushed and fissured, and then 
 brought under the action of solutions which penetrated into it 
 in all directions, and so produced the alteration. The yield is 
 considerably less than J oz. per ton, but as the deposit can be 
 
 * "The Bendigo Gold-Field," Trans. Amer. Inst. M.E., vol. xx. (1891), 
 p. 463. 
 
 t G. M. Dawson, " Notes on the Ore-deposit of the Treadwell Mire, 
 Alaska," American Geologist, 1889, p. 84; and Frank D. Adams, "On the 
 Microscopical Character of the Ore of the Treadwdl Mine, Alaska," 
 p. 88. 
 
48 ORE AND STONE-MINING. 
 
 worked opencast, the cost of getting is low. Much of the gold is 
 free, and can be extracted by amalgamation in spite of its being 
 enveloped by pyrites. 
 
 This mass may be called a stockwork or net-work deposit. 
 
 The productive Mount Morgan mine,* near Rockhampton, in 
 Queensland, while astonishing the world by its richness, affords a 
 puzzle to geologists which has not yet been satisfactorily solved. 
 
 The auriferous deposit, which is worked as an open quarry, is a 
 mass of brown haematite, sometimes stalactitic and containing a 
 little silica, which passes gradually into a ferruginous siliceous 
 sinter. Some of it is spongy and frothy in appearance, and so 
 full of cavities that it will float upon water like pumice. The 
 precise nature of the gold-bearing mass is well illustrated by 
 twenty views which accompany the " Third Report " of Mr. 
 R. L. Jack, the Government geologist. 
 
 Both the sinter and the brown iron ore contain gold, and 
 yield on assay several ounces to the ton. The auriferous stone 
 
 FIG. 39. 
 
 a, pipe of geyser (theoretical) ; b, cup-deposit of geyser ; c, over- 
 flow deposit of geyser ; s, metamorphic rocks ; d, rhyolite dykes. 
 
 cap 5 * a hill rising about 500 feet above the neighbouring table- 
 land, and the most important part of it is the actual top or crown, 
 an oval mass 300 yards long by 170 yards wide. 
 
 Mr. Jack considers that the deposit is the product of a geyser, 
 and he explains his views by the section (Fig. 39). This naturally 
 represents the present condition of the hill, much of the original 
 geyser deposit being supposed to have been removed by denu- 
 dation. 
 
 The gold exists in a state of great fineness, and the metal 
 extracted is of extreme purity, for it contains 99*7 of gold, 
 the rest being copper, a trace of iron, and a minute trace of 
 silver. Dr. Leibius, of the Sydney Mint, speaks of it as the 
 richest native gold hitherto found. 
 
 Without having examined the deposit upon the spot, one 
 scarcely likes to criticise the conclusions of so able an observer 
 as Mr. Jack ; but looking at his section of the No. i tunnel, 
 we find that the auriferous mass must repose upon highly 
 pyritous rocks, such as quartzite full of fine pyrites, in which the 
 latter constituent may sometimes predominate. The suspicion 
 
 * R. L. Jack, " Mount Morgan Gold Deposits." Brisbane, 1884. Second 
 Report, 1889 ; and Third Keport, 1892. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 49 
 
 naturally crosses one's mind that the gold-bearing cap may simply 
 be due to the decomposition and weathering of the pyritiferous 
 rock. Mr. Jack combats this theory, and says that it is dis- 
 proved by three facts : ist. A dyke of dolerite in the quartzite 
 does not reach up into the overlying sinter. 2nd. The pyri- 
 tiferous quartzite is poor in gold. 3rd. The silica of the sinter is 
 hydrated. He therefore still maintains his original opinion that 
 the sinter and ironstone were deposited by a thermal spring on 
 the pyritous quartzite, and are not altered portions of it.* 
 
 Mr. Rickard,t while disagreeing with the geyser theory, 
 concurs in Mr. Jack's opinion that the deposit is not an altered 
 portion of the pyritous quartzite, though he remarkn that the 
 
 FIG. 40. 
 
 Mount Morgan rock bears a strong outward resemblance to the 
 decomposed outcrop of the Broken Hill lode in New South Wales. 
 This can be easily imagined from an inspection of the views given 
 in Mr. Jack's third report, from which the outlines of Fig. 40 
 have been copied. The theory propounded by Mr. Riekard 
 (Fig. 41) is that the auriferous stone of Mount Morgan is rock 
 shattered by the intrusion of dykes, and then altered by thn per- 
 colation of underground mineral solutions, which found an easy 
 passage through the cracked and fissured mass. He points out 
 that the gold may have been derived from the poor pyritca 
 disseminated through the quartzite, or from the sandstone of the 
 district, which has been shown to be auriferous. 
 
 The quantity of stone treated by chlorination at Mount Morgan 
 
 * Second Report, p. 4. 
 
 t "Mount Morgan Mine, Queensland," Trans. Amer. Inst. M.E. vol. nx, 
 (1891), p. 133. 
 
5 ORE AND STONE MINING. 
 
 in the twelve months ended 3oth November, 1889, was 75.415 
 tons, from which 323,542 oz. of gold were obtained, equal to 
 
 FIG. 41. 
 
 MOUNT MORGAN SECTIONS. 
 
 based on late developments ___^_ 
 
 ORE DEPOSIT. INTERSECTED BY SMALL OVKE6 NOT SHOWN RvR-'r^ PYRITlOltt OUABTZITE f*V''v;-'"J 0*08 
 
 4 oz. 6 dwt. per ton. The gold was sold for ^1,3 3 1,484, and 
 ^1, 1 00,000 was paid in dividends. 
 
 Graphite. The great graphite mines of the world are those 
 of Ceylon, where the mineral is found in layers from a few inches 
 to several feet in. width, in gneiss and mica schist. The graphite 
 is associated with quartz and a little iron pyrites. 
 
 There are various graphite deposits in Austria and Bavaria.* 
 A.t Kaiserberg, in Styria, the mineral is found in graphitic schist ; 
 the beds vary in thickness very rapidly from a few inches to 20 feet. 
 
 In Lower Austria, Moravia, Bohemia, and Bavaria graphite 
 occurs in gneiss usually accompanied by granular limestone. The 
 Passau graphite is in the form of small black scales, and appears 
 to take the place of some of the mica in a highly felspathic gneiss ; 
 the thickness of the beds varies greatly, but may be as much as 
 1 6 feet (5 m). 
 
 The Bavarian mines produced 3352 tons of graphite in 1888. 
 
 Gypsum. As one of the principal uses of gypsum is for 
 making plaster-of-paris, we naturally turn to the French 
 metropolis for an example of the mode of occurrence of this 
 mineral. The gypsum is found in beds from 50 to 60 feet thick, 
 which are of Upper Eocene age (Fig. 352). 
 
 In England and elsewhere, the Triassic rocks have long been 
 remarkable for containing valuable beds of gypsum, and they are 
 largely worked in Derbyshire and Nottinghamshire. Fig. 42 re- 
 presents the layers of nodules in a gypsum mine at Kingston-on- 
 Soar, Nottinghamshire. There are three beds a few feet apart in 
 the New Red Marl. The bottom bed consists of large spheroidal 
 masses, varying from 5 to 8 feet in thickness, and 5 to 10 feet in 
 diameter ; above it are two layers of " balls " and nodules, more 
 or less continuous. The highly gypsiferous marl, locally called 
 
 * Th. Andree, "Der osterreichische und bayeriscln Graphiibergbau," 
 J3. u. k. Z. 1890, p. 269. 
 
FIG. 42. 
 
 MODE OF OCCURRENCE Otf MINERALS. 51 
 
 " fault,'' B, between the big balls, A A, is left, so as to form pillars, 
 which support the roof of the workings. 
 
 White translucent alabaster for statuary purposes is mined at 
 Castellina Marittima,* in the province of Pisa. Its mode of 
 occurrence resembles that just de- 
 scribed, for it is found in irregular 
 spheroidal or kidney-shaped masses 
 called " ovuli" by the workmen, from 
 a few inches to several feet in dia- 
 meter, and occasionally weighing 
 more than a ton each. The grey 
 marl surrounding the nodules is of 
 Pliocene age. The alabaster is sac- 
 charoidal and very fine grained. 
 
 Ice. By some persons this mineral 
 may be considered beneath notice, but 
 the trade in ice is so large that it 
 deserves at least a passing mention. 
 The United States f are the largest 
 producers of natural ice in the world, 
 and in some years 12,000,000 tons are gathered from the lakes 
 and rivers, and especially from the Hudson. The gathering in of 
 the ice crop affords employment to " 12,000 men and boys, 1,000 
 horses, and 100 steam engines." Much ice is exported from 
 Boston, and Norway also is a country with a large ice trade. 
 
 Iron. This metal is very widely distributed over the globe, 
 and affords examples of many modes of occurrence, though veins 
 of iron ore are quite driven into the background by the yield of 
 beds, and especially those of the Jurassic age. 
 
 The most productive European deposits at the present time 
 are : the bed of iron ore in the Cleveland district, the masses of 
 red haematite in Cumberland and North Lancashire, the bed of 
 brown haematite in German and French Lorraine, and Luxem- 
 burg, and the beds of red and brown haematite near Bilbao, in 
 Northern Spain. 
 
 The bed of ironstone worked in the Cleveland district of North 
 Yorkshire is found in the Middle Lias. Mr. Kendall J gives the 
 following general section of the rocks : 
 
 * Jervis, Itesori sotterranei delV Italia, vol. ii. p. 419, and vol. iv. p. 318. 
 
 t "The Trade in Ice," Jour. Sac. Arts. London, 1890, vol. xxxviii. 
 P- 765- 
 
 "The Iron Ores of the English Secondary Rocks," Trans. N. of Eny. 
 Inst. Min. Eng., vol. xxxv. (1886), p. 113. Barrow, "The Geology of North 
 Cleveland," Mem. Geol. Survey 1888. 
 
ORE AND STONE-MINING. 
 
 Description. 
 
 Thick- 
 ness. 
 
 Characteristic Ammonite. 
 
 /Shale with cement stone 
 
 ft. in. 
 
 
 TT nodules (alum shale series) 
 
 115 o 
 
 A. communis 
 
 u P per -1 Shale with doggers* (jet rock 
 Llas series) .... 
 
 48 o 
 
 A. serpentinus 
 
 \ Grey shale with doggers 
 
 30 o 
 
 A. annulatus 
 
 
 Ironstone (Main seam) . 
 Shale with doggers 
 
 ii 6 
 
 10 6 
 
 j. A. spinatus 
 
 ) 
 
 
 Ironstone (bottom seam) 
 
 2 9 
 
 
 
 Shale with nodules of clay 
 
 
 
 Middle , 
 
 ironstone .... 
 
 20 
 
 
 Lias 
 
 Ironstone in thin bands 
 Shale with ferruginous 
 
 i 9 
 
 A. margaritatus 
 
 
 dcggers .... 
 
 30 o 
 
 
 
 Sandstone, sometimes flaggy, 
 
 
 
 
 ^ calcareous, and ferruginous 
 
 40 o 
 
 
 
 
 '" A. capricornus, Ja- 
 
 T (Shale with numerous thin 
 %. r J limestones in the lowest 
 
 
 mesoni, armatus, 
 - oxynotus, Buck- 
 
 ijias 
 
 300 feet .... 
 
 700 o 
 
 Ian di, angulatus, 
 
 
 
 and planorbis 
 
 Fig. 43! illustrates sections of the bed at Eston and Upleatham. 
 
 FIG. 43. 
 
 Estorv 
 
 Grey shale and ferruginous nodules . . 
 
 Ironstone (top block) in alternate hard and\ '. 
 soft layers i not worked ... J 
 
 Ironstone (mainbtock}, workable part of bed \ 
 atpresent / 
 
 Ironstone (bottom block) not worked . , i'/0 
 Shale ........ 
 
 The Main Seam practically furnishes all the Cleveland ore. It 
 probably extends over an area of 350 square miles, though it 
 
 * Doggers are nodules of ironstone. 
 t Kendall, Op. cit. Fig. 5, Plate XIII. 
 
MODE OF OCCURRENCE OF MINERALS. 53 
 
 cannot be profitably worked over anything like the whole of this 
 district. The average thickness where worked is about 10 feet. 
 The beds dip very gently about i in 15, to the south-east. The 
 seam is thickest and best at Normanby, Eston, and Upleatham ; 
 in proceeding to the south-east, partings of shale appear, and 
 split up the main seam into numerous comparatively thin layers 
 of ironstone, with a smaller percentage of metal. Some of the 
 ironstone is oolitic and of a greenish grey colour, but much of it 
 is not oolitic, and is bluish grey in colour, resembling a mudstone. 
 The iron exists chiefly as carbonate, some of which, according to 
 Dr. Sorby, was deposited mechanically, whilst the rest was formed 
 chemically by replacement of carbonate of lime. As a general 
 average, it may be said that the ore contains 30 per cent, of 
 iron. The district produced 5,128,303 tons of, ore in 1891. 
 
 The masses of red haematite worked in Cumberland and North 
 Lancashire have already been noticed (Fig. 14). 
 
 The great iron-field of Lorraine,* much of which became the 
 property of Germany in 1871 after the Franc >-Prussian war, 
 stretches out from Nancy past Metz and Diedenhofen into 
 Luxemburg. It may be called 60 miles long by 10 to 12 miles 
 wide (100 km. by 15 to 20 km.). 
 
 The iron-bearing strata belong to the Lower Dogger or Brown 
 Jura (Inferior Oolite), and consist of marly sandstone, marl and 
 sandy clay, interstratified with beds of limestone and iron ore. 
 
 In places there is no iron, and in others, especially in the south 
 and on the eastern edge, the beds of ore are thin. On the other 
 hand, at Esch, in Luxemburg, four beds of iron ore and their 
 partings of limestone and sandstone make up a total thickness of 
 65 feet (20 m.), and at Deutsch-Och and Oettingen three beds and 
 the partings are 32 feet (10 m.) thick; then at Hayingen the total 
 thickness sinks to 20 feet (6 m.), and at Ars there is only one bed 
 5 to 6 feet thick. The strata are slightly undulating, but the 
 general dip is i to 2 J in a hundred to the south-west. The iron 
 exists in the state of hydrated oxide, probably for the most part 
 as 2Fe 2 3 3H 2 O, which constitutes the roe-like grains which are so 
 characteristic of the ore. 
 
 The oolitic particles are enclosed in a calcareous matrix, which 
 may contain quartz. The matrix is always more or less ferru- 
 ginous, and sometimes consists of a greenish mineral, which is 
 probably a silicate of iron. The ore has usually from 32 to 38 
 per cent, of iron and from J to 2 per cent, of phosphorus ; there is 
 also a little sulphur, due to occasional small strings of iron 
 pyrites. The name " minette," or " little, unimportant ore," was 
 given many years ago to this bed in contradistinction to the 
 
 * Wandesleben, " Das Vorkommen der oolithischen Eisenerze (Minette) 
 in Lothringen, Luxemburg und dem ostlichen Frankreich." Der I V. All- 
 yemeine Deutsche Bergmannstag in Ualle (Saale). Festbericht und Ver- 
 iMndlunyen, Halle, 1890, p. 297. 
 
54 
 
 ORE AND STONE-MINING. 
 
 " mine" or " mineral de fer fort," a much richer ore found in the 
 neighbourhood, which is now no longer worked. 
 
 Nearly a hundred blast furnaces are dependent upon the 
 " minette " for their supplies of ore, and in 1888 they produced 
 2,500,000 tons of pig iron, or 40 per cent, of the total production 
 of Germany, Luxemburg, and France. More than four-fifths of 
 all the iron ore raised in this last country is obtained from this 
 bed. The amount of ore still available in German Lorraine is 
 estimated at 2,100 million tons, or enough to maintain the pre- 
 sent rate of production for 750 years. 
 
 Sweden is justly famous for its great deposits of magnetite. 
 These are generally lenticular masses, often similar in shape to 
 the Rio Tinto copper veins, and enclosed by highly metamorphosed 
 rocks, such as gneiss, mica schist, and the hard compact hdlleflinta 
 of the Swedish geologists. 
 
 It would not be right to quit the subject of iron ore without 
 mentioning at least one of the mines situated in the neighbour- 
 hood of Lake Superior, where the Menominee, Gogebic, Vermilion 
 and Mesabi districts are producing large quantities of mineral. 
 
 At Chapin Mine* near the town of Iron Mountain (Mich.) 
 there are huge lenticular masses of haematite, which lie parallel 
 to the enclosing Huronian strata (Fig. 44). t One large lens is 
 
 FIG. 44. 
 
 half a mile long, 130 feet wide in the middle, and gradually 
 tapering out to a point at each end ; it strikes 15 N. of W., and 
 dips from 70 to 80 N., and the axis of the lens pitches 30 W. 
 The ore contains about 63 per cent, of metallic iron, and only 
 o - o7 per cent, of phosphorus. 
 
 * Larsson, "The Chapin Iron-mine, Lake Superior," Tram. Amer. List. 
 U.E., vol. xvi. (1887), p. 119. 
 f Engineering, vol. 1. (1890), p. 552. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 55 
 
 Load. Though lead ore is largely wrought from veins, one of 
 the great mines in the world obtains its supplies from a bed. The 
 lead-bearing sandstone at Mechernich, in Rhenish Prussia,* is of 
 Triassic age (Bunter) and is on an average nearly 100 feet thick. 
 It rests upon and is covered by conglomerate, and is often split up 
 into two or more beds by thick partings of conglomerate. The 
 ore exists in the form of little concretions of galena and grains of 
 quartz, but these are not uniformly distributed through the sand- 
 stone. The concretions are from ^ inch (i mm.) to J inch (3 mm,) 
 
 FIG. 45- 
 
 A, greywacke ; B, conglomerate ; C, lend-bearing sandstone; 
 D, conglomerate ; E, so-called "red rocks," consisting of red, 
 yellow, and white sandstone, with variegated shales and clay. 
 
 in diameter, and are harder than the surrounding sandstone, 
 which is generally very friable. When the rock is pulverised 
 the little shot-like masses remain, and are called "knots" (Knotten), 
 whence the name " Knottensandstein " given to the bed. The 
 amount of metallic lead in the sandstone is between 2 and 
 3 per cent. ; but the concretions themselves contain from 20 to 24 
 per cent. According to the statement of accounts presented to 
 the shareholders,t the average percentage of lead contained in 
 the whole of the sandstone treated in 1890 was 2'3i8; 347,706 
 cubic metres (454,806 cubic yards) of sandstone, were raised from 
 the mine and open work, and yielded 36,245 tons of lead ore for 
 smelting and 733 tons of potter's ore. This would be at the rate 
 of io4kil. of dressed ore per cubic metre, or i| cwt. per cubic yard, 
 but it must not be forgotten that the bulk of the ore i.e., that 
 which goes to the furnaces is not highly concentrated and con- 
 tains only 54 per cent, of metal. The proportion of silver in it is 
 5! ounces (180 grammes) per metric ton. 
 
 The history of Leadville, in Colorado, seems like a romance 
 when we read of the rapid development of the mines, the creation 
 of a large and important town, the erection of smelting works 
 and the building of railways, under very adverse conditions, in 
 
 * Der Berybau und Hiittenbetrieb des Mechernicher Berqtoerks-Actifn- 
 Verew*. Cologne, 1886. 
 t Mining Journal, vol. Ixi. (1891), p. 499. 
 
ORE AND STONE-MINING. 
 I 
 
MODE OF OCCURRENCE OF MINERALS. 57 
 
 the heart of the Rocky Mountains, all within the space of four or 
 five years. It affords additional proof that the miner is the true 
 pioneer of civilisation. The Leadville deposits have been ad- 
 mirably described by Mr. S. F. Emmons,* from whose exhaustive 
 report I borrow, not only the following facts, but also a section 
 across one of the mines (Fig. 46). 
 
 The principal deposits of the region are found at or near the 
 junction of white porphyry with the underlying Blue Limestone, 
 which is the lowest member of the Carboniferous formation. 
 This bed is about 150 or 200 feet thick, and consists of dark-blue 
 dolomitic limestone. At the top there are concretions of black 
 chert. The porphyry occurs in intrusive sheets, which generally 
 follow the bedding, and almost invariably a white porphyry is 
 found overlying the Blue Limestone. This porphyry is of 
 Secondary age. It is a white homogeneous-looking rock, com- 
 posed of quartz and felspar of even granular texture, in which the 
 porphyritic ingredients, which are accidental rather than essen- 
 tial, are small rectangular crystals of white felspar, occasional 
 double pyramids of quartz, and hexagonal plates of biotite or 
 black mica. Along the plane of contact with the porphyry the 
 limestone has been transformed, by a process of gradual replace- 
 ment, into a so-called <; vein " consisting of argentiferous galena, 
 cerussite, and kerargyrite, mixed with the hydrous oxides of iron 
 and manganese, chert, granular cavernous quartz, clay, heavy spar, 
 and " Chinese talc," a silicate and sulphate of alumina. The vein 
 seems to have been formed by aqueous solutions, which took up 
 their mineral contents from the neighbouring eruptive rocks, and 
 brought about the alteration of the limestone as they percolated 
 downwards through it. In Carbonate Hill a gradual passage may 
 be observed from dolomite into earthy oxides of iron and manga- 
 nese. The masses of workable ore are extremely irregular in 
 shape, size, and distribution. They are often from 30 to 40 feet, 
 thick vertically, and occasionally 80 feet, but only over a small 
 area. The rich ore bodies are commonest in the upper part of 
 the ore-bearing stratum. At Fryer Hill the Blue Limestone is 
 almost entirely replaced by vein material. The metallic ores 
 appear to have been deposited originally as sulphides ; the oxidised 
 or chloridised ores found near the surface are the products formed 
 by the percolation of surface water like any ordinary gozzan. 
 
 Manganese. The great manganese-producing countries of the 
 present day are Russia f and Chili, and in both, the ore is derived 
 from beds, and not from veins or masses. At Tschiatoura in the 
 Caucasus, about thirty miles from Kwirilly station on the Poti- 
 Tiflis Railway, there are beds of manganese ore of Miocene age. 
 The beds worked are from 5 to 6 feet thick (1*5 m. to 2 m.), and 
 
 * Geology and Mining Industry of Leadville, Colorado. Washington, 
 1886. 
 t B. u. h. Z. 1890, pp. 32, 215. 
 
58 ORE AND STONE-MINING. 
 
 are made up of several small seams of clean manganese ore, 
 separated by partings of soft sandstone and clay. The manganese 
 exists principally in the form of Mn0 2 , and the ore contains 
 50 to 55 per cent, of metal. The mines are at present heavily 
 handicapped by the long and expensive carriage to Kwirilly 
 station, but this will be reduced when a railway is made. 
 
 Both in Wales and Belgium there are beds of manganese ore in 
 the Cambrian rocks. The Welsh beds are about a foot thick (Fig. 
 
 47), sometimes running up to 
 
 FlG - 47- 1 8 inches or 2 feet. The man- 
 
 ganese is principally in the 
 form of carbonate, though 
 r c there is a little silicate, and 
 Ev= near the surface these have 
 
 been converted into hydrous 
 oxides. The ore is inter- 
 bedded with fine - grained 
 sandstone, hard mudstone, 
 and shale, also manganifer- 
 ous, and often containing 
 -^ chlorite, iron pyrites, and 
 
 magnetite; the whole man- 
 ganiferous series is enclosed 
 //*. in the regular Cambrian grits 
 and conglomerates. The ore 
 o ' so ' j cJ 5a?lflie>c * contains from 20 to 32 per 
 
 A, fine-grained sandstone with ma*- cent ' manganese, 
 netite, ch'orite, and iron pyrites; B, Marble. The famous 
 manganese ore; C, fine-grained shaly white statuary marble of 
 sandstone. Italy is found in the Apuan 
 
 Alps from Carrara to Staz- 
 
 zema, on the S.W. slope of the mountains, and from Fivizzano to 
 Vagli Sotto on the N.E. slope.* It occurs in very thick beds, 
 with the stratification sometimes well defined, but generally 
 completely obliterated, and it rests upon compact limestone, which 
 in its turn lies upon pre-p ilreozoic mica-schist and talc-schist. 
 The age of the marble beds has not been ascertained without 
 doubt; some geologists say they are Triassic, whilst Jervis calls 
 them pre-palreozoic. 
 
 Mica. This mineral is obtained in North Carolina at the 
 present time, just as it was in the days of the prehistoric mound 
 builders, from veins of giant granite, or granite in which the con- 
 stituent minerals have crystallised on a huge scale. According to 
 Phillips,! a single block of mica has weighed nearly a ton, and 
 
 * Jervis, / Tesori so'terranei d<W Italia, vol. iv. p. 261. 
 t "Mica Mining in North Carolina," Eng. Jllin. Jour. t vol. xlv. (1888). 
 p. 286. 
 
MODE OF OCCURRENCE OF M^N^RALS. 59 
 
 pieces 6 feet long and 3 feet wide are sometimes met with ; a single 
 crystal of felspar weighing 800 Ib. is preserved in the State 
 Museum at Raleigh. The veins are from 30 to 40 feet wide, and 
 are enclosed in mica schist, of which they follow the strike and 
 dip ; but they occupy fissures which took place along planes of 
 easy fracture, and being of subsequent origin to the surrounding 
 rocks, are veins and not beds. 
 
 W atural Gas.* Though the Chinese were before the Ameri- 
 cans in their use of natural gas, it is to the United States that we 
 must look for examples of gas springs, which have been so largely 
 turned to account during the last ten years, more especially in 
 Pennsylvania, but also in Ohio and New York. 
 
 According to the late Mr. Ashburner,f the gas in these States 
 comes from beds of Palaeozoic sandstone and limestone. He 
 considers, with many others, that both gas and petroleum 
 have been formed by the decomposition of animal and vegetable 
 remains in the rocks, and that in order to have a productive gas 
 region, it is necessary that there should be a porous or cavernous 
 rock to contain the gas, and an impermeable covering, such as 
 shale, to prevent its escape, conditions resembling those required 
 for artesian wells. A further condition is that the strata should 
 be bent into a dome, anticlinal or arch, at the crown of which 
 the gas will be found ; but if the rocks have been much disturbed, 
 contorted, and fissured, natural vents have been formed, through 
 which the gas will have escaped. The rocks now containing the 
 gas are often those in which it was generated. 
 
 There are several gas-producing beds of sandstone in Pennsyl- 
 vania, in the Carboniferous rocks ; but the most important supplies 
 are obtained from sands of the Yenango- Butler oil-group, belong- 
 ing to the Catskill Rocks of the Devonian period. There are 
 other gas-sands in the Chemung and Portage rocks, also of the 
 Devonian Period, but lower down. Some of them produce both 
 gas and oil. 
 
 The most productive gas-bearing rocks in Ohio are the Berea 
 grit in the Sub-carboniferous period, and the Trenton Limestone 
 in the Lower Silurian period. 
 
 The section (Fig. 48)4 shows the Silurian and Devonian strata 
 bent into an arch or dome at Findlay, Ohio, where gas and petro- 
 leum are obtained by boring into the Trenton Limestone, the 
 reservoir in which they are confined by the Utica Shale. 
 
 The gas varies in composition, not only from well to well, but 
 also from time to time in the same well. Some analyses given by 
 Prof. Lesley show that the gas of a certain well contained upon 
 
 * Topley, " The Sources of Petroleum and Natural Gas," Jour. Soc. Arts, 
 vol. xxxix. (1891), p. 421. 
 
 t " The Geoloeic Distribution of Natural Gas in the United States," 
 Trans. Amer. Jnst. M.E., vol. xv. (1886-87), P- S5- 
 
 I Topley, Op. cit. p. 413. 
 
ORE AND STONE-MINING. 
 
 FIG. 48. 
 SECTION THROUGH FINDLA.Y, OHIO. (Orton.) 
 
 X-X Sea Lev el 
 
 Devonian 
 
 Silurian 
 
 7. Ohio shale. 
 
 6. Upper Helderberg limestone. 
 
 5. Lower Helderberg limestone. 
 
 ( Niagara limestone. 
 4. \ Niagara shale. 
 
 (Clinton limestone. 
 
 | Hudson River shale. 
 '* (Medina shale. 
 2. Utica shale. 
 >i. Trenton limestone. 
 
 different occasions from 50 to 75 per cent, of marsh gas, 9 to 35 
 per cent, of hydrogen, 4 to 12 per cent, of ethylic hydride with 
 small quantities of olefiant gas, oxygen, carbonic oxide and 
 carbonic acid, and in one instance as much as 23 per cent, of 
 nitrogen, though usually this gas was absent. The pressure of 
 
 the escaping gas is often very 
 great, and in one case reached 
 450 Ib. per square inch. 
 
 Nickel. Until recently 
 our supplies of this metal 
 were obtained from sulphides 
 or sulpharsenides, and espe- 
 cially from nickel-bearing 
 pyrrhotine. The discovery 
 by Gamier of hydrated sili- 
 cate of nickel and magnesium 
 in New Caledonia revealed 
 the existence of an unsuspected source of wealth. The nickel is 
 found in serpentine,* either at the contact of this rock with 
 " pockets " of red clay, or near such a contact, but never in the 
 day itself. 
 
 * Levat, "Memoire sur les progres de la metallurgio du Nickel," Ann. 
 Mines, 96 serie, vol. i. (1892) p. 141. 
 
 itic brown iron ore. 
 S Serpentine. 
 A Red Clay. 
 
MODE OF OCCURRENCE OF MINERALS. 61 
 
 Figs. 49, 50, and 51 are examples of various types of such 
 deposits. In all three cases A is the pocket of red clay, and S is 
 the serpentine. In Fig. 49 
 
 the nickel ore lies between FIG- 5 
 
 the rock and the clay. In 
 Fig. 50 there are a number 
 of interlacing veins in the 
 serpentine forming a net- 
 work deposit which is quar- 
 ried, whilst in the case re- 
 presented by the Fig. 51, 
 the original fissures were 
 bigger, but less numerous, 
 and are now filled up with 
 nickel ores forming veins 
 20 to 26 feet in width. The ferruginous red clay often contains 
 the hydrated oxides of manganese and cobalt, besides chromic iron 
 (Fig. 19). Large lumps of 
 limonite are frequently 
 found lying upon the 
 clay, Fig. 49. The ore 
 which is exported has 
 from 7 to 1 8 per cent, of 
 nickel. 
 
 Of still later date are 
 the discoveries of nickel 
 ore at Sudbury* on the 
 
 Canadian Pacific Railway, about 40 miles north of Georgian Bay. 
 Here the ore is a nickel-bearing pyrrhotine associated with 
 
 FIG. 52. 
 
 a, Huronian strata ; 6, diorite ; c, ore-body ; *, shaft ; x x, boreholes. 
 
 chalcopyrite. These two minerals form large ore bodies (Figs. 
 52 and 53) in or near a belt of diorite in a district occupied 
 
 * Collins, " On the Sudbury Copper Deposits," Q. J. G. S., vol. xliv. 
 (1888), p. 834, from which paper the two figures are borrowed. Snelus 
 and Colquhoun in the special volume of Proceedings, The Iron and Steel 
 Institute in America in 1890, pp. 213, 359. 
 
62 
 
 ORE AND STONE-MINING. 
 
 by rocks belonging to the Huronian and Laurentian systems. 
 The shape of the ore bodies is very irregular, but their size is 
 great ; some are hundreds of feet long, by a hundred or more 
 feet in breadth. The two minerals are worked and treated 
 
 FIG. 53. 
 
 FIG. 54. 
 
 a, Huronian rocks ; 6, diorite ; c, ore-mass ; 8, shaft on diagonal vein. 
 
 together, for picking by hand has been found to be impracticable 
 on a commercial scale, and separation by the ordinary washing 
 process is impossible, owing to the small difference between their 
 specific gravities. 
 
 Ore of good average quality contains 4 per cent, of nickel. 
 Nitrate of Soda. The existence of beds of nitrate of soda, 
 cubic nitre, in the rainless regions on the West Coast of South 
 
 America had been noticed in 
 books on mineralogy for many 
 years ; but it was not till this 
 mineral was found to be a valu- 
 able fertiliser that steps were 
 taken to work it on a large 
 scale. 
 
 The raw nitrate of soda 
 (caliche) is found in beds from 
 6 inches to 12 feet thick, be- 
 neath a covering of hard con- 
 glomerate (costra) from i to 10 
 
 feet thick, as shown in Fig. 
 
 a, soft earth : 0, caliche , e, con- * T , . , ,-, , ., 
 
 glomerate ; d, sand ; e, charge of gun- 54-* ^ is supposed that_ it 
 powder ; /, tamping ; g, safety-fuse. has been formed by the action 
 
 of animal and vegetable 
 
 matter upon salt left by the evaporation of sea- water, and this 
 theory is supported by the fact that guano and the remains of 
 
 * Harvey, " Machinery for the Manufacture of Nitrate of Soda at the 
 Ramirez Factory, Northern Chili," Proc. last. C.E., vol. Ixxxii. (Session 
 1884-85), p. 337. 
 
 
MODE OF OCCURRENCE OF MINERALS. 63 
 
 birds and fish are found close to the caliche, and also by the 
 presence of iodine, an element pertaining to the sea, in. the form 
 of iodides and iodates. 
 
 Another theory, that of Dr. Carl Ochseoius,* is that salt lakes 
 were formed by the elevation of a barrier which shut out the sea, 
 that these gradually evaporated, that carbonic acid due to 
 volcanic agencies converted some of the chloride of sodium into 
 carbonate, and that finally guano dust, wafted by the prevailing 
 breeze from guano islands near the coast, brought nitrogenous 
 matter, which eventually became oxidised and converted the 
 carbonate into nitrate. 
 
 An analysis of caliche given by Mr. Harvey is as follows : 
 
 Per cent. 
 
 Nitrate of scda 51 
 
 Common salt 26 
 
 Sulphate of soda 6 
 
 Sulphate of magnesia ..... 3 
 Insoluble matter 14 
 
 100 
 
 This sample was richer than the average ; for the best caliche 
 contains about 40 to 50 per cent., middle 30 to 40, and poor 
 caliche 17 to 30 per cent, of nitrate. 
 
 Ozokerite. The most productive ozokerite mines are found at 
 
 SCALE 
 
 1400 MtTRCS 
 
 200 400 600 600 1000 1200 1400 I600YARDS 
 
 Boryslaw, near Drohobycz, in Galicia. The mineral occurs in an 
 oval area some 1,500 yards long and a quarter of a mile wide at 
 the broadest part, with the long axis, AB, running in a N.W. and 
 
 * Ertg. Mln. Jcurn., vol. xlvi. (1888), p. 152. 
 
6 4 
 
 ORE AND STONE-MINING. 
 
 S.E. direction, or parallel to the trend of the Carpathians* (Fig. 55). 
 The surrounding rocks are beds of sandstone and shale of Miocene 
 age, bent into a dome like a dish-cover, whilst the productive 
 area itself consists of the same strata traversed by a main set of 
 
 fractures in the direction AB (Fig. 55), and numerous cross- 
 fractures. In this mass of shattered, crushed, and faulted rock 
 the ozokerite has been deposited ; it fills every crack and crevice 
 into which it could penetrate, sometimes crossing the stratification 
 
 SCALB. 
 
 Inches 12 6 
 
 a feet 
 
 6or 80 too 
 
 and sometimes following the planes of bedding for some distance, 
 and then breaking across in an irregular manner (AB, Fig. 57). 
 The veins vary in thickness from a mere knife-edge to several feet. 
 Fig. 56 is a diagrammatic section along the line CD (Fig 55), 
 and is intended to convey some idea of the jumble of rocks between 
 E and F, the centre part from G- to H being specially cracked, 
 and faulted. The richest mines are those sunk in the 
 
 deeply-shaded part of the plan, corresponding to GH of the 
 section. Petroleum is found in the rocks within the ozokerite 
 area and also in those surrounding it for a certain distance, but 
 there is less on the north side than on the south. 
 
 * For much of the information concerning Boryslaw, I am indebted to 
 explanations given to me on the spot by Mr. A. Platz, manager of the 
 largest mine. 
 
MODE OF OCCURRENCE OF MINERALS. 65 
 
 Petroleum. The conditions under which rock-oil is found 
 in the earth's crust are precisely the same as those described in 
 speaking of natural gas, viz., a porous bed for storing the 
 mineral, an impermeable bed for preventing its escape, and 
 very often an anticlinal arrangement of the strata, though this is 
 of less importance than in the case of gas. 
 
 The three great oil regions of the world at present are 
 Baku, Burmah, and Pennsylvania. I put Baku first, because 
 the existence of the eternal fires of the Apsheron Peninsula 
 on the Caspian Sea has been known for about 2,500 years, 
 and because some of its wells have surpassed in productiveness 
 anything met with elsewhere. The principal wells are in the 
 
 N.B. 
 
 Lalakhani-Saboontshi district, some eight miles North of Baku, 
 and at Bibi-Eibet, a little to the south. The rocks are of Lower 
 Miocene age,* and consist of sand, calcareous clays, marls, and in 
 places compact sandstone. The sectionf (Fig. 58, after Abich) 
 shows the wells on the crown of a low anticlinal. The petroleum 
 is found in three well-defined beds of sand ; these sands are in a 
 semi-fluid condition and contain salt water in addition to petroleum 
 and carburetted hydrogen gas. Sometimes the pressure of the 
 gas amounts to 300 Ibs. per square inch. 
 
 At some of the wells it is necessary to pump up the petroleum, 
 but at others it rises naturally and occasionally with great force 
 and in immense quantities. In fact, Tagieff's spouterj in 1886 
 actually threw up, on the eighth day after oil had been struck, 
 the immense quantity of 11,000 tons or 2f millions of gallons in 
 twenty-four hours. The flow then diminished and was got under 
 control by the engineers, and reduced to a quarter of a million 
 gallons a day. Fig. 59, copied from a photograph, represents a 
 spouting well at Baku. 
 
 The principal oil-fields of Burmah || are situated near the 
 villages of Twingoung and Berne, about a mile and a half east of 
 Yenangyaung on the Irrawaddy, and 130 miles south of 
 Mandalay. The rocks belong to the Tertiary period and are 
 probably of Miocene age, the prevailing strata being clayey sands 
 
 * Vasilieff, "The Oil Wells of Baku," Proc. List. C.E., vol. Ixxxiii. 
 (1885-6), p. 406. 
 
 Topley, Op. cit., p. 429. 
 
 Marvin, The Coming Deluge of Russian Petroleum. London, 1886, p. 9. 
 Lent to me by Mr. Boverton Redwood. 
 
 || F. Noetling, " Report on the Oil Fields of Twingoung and Berne, 
 Burma," Records of Geol. Survey of India, vol. xxii. (1889), p. 75. 
 
 E 
 
66 
 
 ORE AND STONE-MINING. 
 
 and soft sandstone. The petroleum is found in beds of soft sand- 
 stone, which, together with partings of blue clay, have been proved 
 to be 200 feet thick, and are probably very much more. The sand- 
 stone is soaked with petroleum, which oozes gradually into the wells, 
 but certain layers are richer in petroleum than others. The 
 lower strata of the formation are more productive than the upper 
 ones. The oil-bearing rocks are overlain by thick beds of blue 
 
 FIG. 59. 
 
 clay which prevent the petroleum from rising. The greatest depth 
 reached by a Burmese well is 310 feet. Noetling thinks that the 
 oil was produced in the sandstone formation in which it is now 
 found, though perhaps not in the uppermost beds. 
 
 At present there are no flowing wells, but these might be obtained 
 if the oil-bearing strata were tapped at a greater depth, for then 
 the gas which accompanies the petroleum would be under greater 
 pressure. Where beds lie as shallow as they do at the existing 
 workings, the gas has already drained off to a great extent through 
 cracks in the strata. The highest daily yield of a single well was 
 500 viss,* but many of what can be called fairly rich wells pro- 
 duced upwards of 100 viss a day. The yield decreases rapidly 
 during the first two years to the extent of at least 25 per cent., 
 and after ten or fifteen years a well does not produce more than 
 5 per cent, of what it did at first. The total daily production of 
 the two fields ranges from 15,000 to 20,000 viss per day. 
 
 Ibs. 
 
MODE OF OCCURRENCE OF MINERALS. 67 
 
 The year 1859 marks the first discovery of petroleum on a 
 commercial scale in the United States, though the oil had been 
 known as long ago as 1627. 
 
 The strata which yield oil in Pennsylvania and New York 
 belong to the Devonian and Carboniferous periods. They are 
 beds of sand and sandstone, sometimes coarse-grained, and are 
 the same as those producing gas; in fact a well may often produce 
 both gas and petroleum, or first gas and then a little oil. In 
 Ohio the two chief sources of oil are the Trenton Limestone 
 [Lower Silurian] and the Berea Grit near the base of the 
 Carboniferous rocks.* 
 
 Phosphate of Lime. The trade in this fertiliser is very 
 large, and fortunately the sources of supply are numerous. 
 Deposits of phosphate of lime are found in rocks of all ages, from 
 the Laurentian to the recent period. I may mention specially 
 apatite from Canada, and various kinds of phosphate from the 
 Cretaceous rocks in Europe, from South Carolina, Florida, and 
 the West Indies. 
 
 The Laurentian rocks are the home of the apatite in Canada. 
 The principal mines are in the county of Ottawa (Q.), and the 
 mineral occurs mainly in pyroxenite, sometimes as a contem- 
 poraneous bed and sometimes as a vein of posterior origin. 
 
 The beds are from i foot to 3 or 4 feet thick, and the veins from 
 a few inches to 8 or 10 feet wide. 
 
 Though worked to some extent in Bedfordshire, Buckingham- 
 shire, and Cambridgeshire, the Cretaceous rocks have of late 
 years yielded far more abundant supplies of phosphate in France 
 than in England. In the mining district of Arras f deposits of 
 phosphate of lime are worked in three horizons: (i) At the base 
 of the Gault, in the form of a bed of nodules, generally about 2 
 inches thick, and sometimes as much as 6 inches thick ; (2) above 
 the Gault, in the form of beds of nodules, 6 inches (15 cm.) to 
 3 feet 3 inches (i m.) thick; (3) in the state of sand, in more or 
 less regular pockets, in the upper beds of the Chalk. This sandy 
 phosphate is covered by a bed of clay with flints, above which 
 comes brick-earth (Fig. 60). The sides of the pockets are formed 
 by the chalk with Micraster cor-anyuinum, or "Santonien"; 
 whilst the fossils in the pockets belong to the base of the 
 " Senonien," or chalk with Belemnites quadratus. The pockets 
 are generally contiguous to each other, but vary a good deal 
 in depth up to 65 feet (20 m.). The phosphatic deposit is a 
 
 * Ashburner, Op. cit. Topley, Op. cit. Weeks, " Petroleum," Mineral 
 Resources of the United States. Calendar Year 1886. Washington, 1887, 
 p. 458 ; and Calendar Years 1889 and 1890, p. 287. 
 
 "I" Statistique de VIndustrie Minerale et des appareils d, vapeur en France 
 ct en Alyerie pour Vannee 1886. Paris, 1888, p. 243. Figure 60 is taken 
 from my own notes, and differs slightly from the one given in the official 
 volume. 
 
68 
 
 ORE AND STONE-MINING. 
 
 very fine yellowish and occasionally white sand, which under the 
 microscope is found to consist of transparent concretionary grains, 
 
 FIG. 60. 
 
 . v 
 
 SCALES:- 
 
 JOUETRES. 
 
 A, chalk ; B, phosphatic chalk ; C, sandy phosphate of lime ; 
 D, clay with flints ; E, brick-earth ; F, soil. 
 
 made up of concentric layers ; its average thickness may be taken 
 at 3 feet 4 inches (i m.) The chalk adjacent to the pockets is 
 
 often phosphatic. M. Merle and 
 FIG. 61. other geologists think that the 
 
 phosphate is derived from the 
 
 '' .;.' .^lisr^'TT^^rT-."' ^^-^^r. p lixiviation in situ of the chalk 
 
 with belemnites by rain water 
 containing carbonic acid. 
 
 The famous beds of South 
 Carolina,* besides satisfying to a 
 great extent the wants of the 
 United States, are able to supply 
 large quantities of the fertiliser 
 to other countries. They were 
 f^^ in 1867, and owing to 
 the facility with which they can 
 be worked and their proximity 
 to a seaport, the trade has in- 
 creased very rapidly. The mineral occurs in the form of 
 nodules, from the size of a pea to that of a man's head, in a 
 bed from a few inches to 2^ feet thick, the average thickness being 
 7 to 9 inches (Fig. 61). With the nodules are found bones of fish 
 and especially teeth of great sharks, together with teeth of the 
 
 
 A, Ashley marl (Eocene) ; B, bed 
 of phosphatic nodules ; C, ferru- 
 ginous sand ; D, clayey sand. 
 
 * R. A. F. Penrose, "Nature and Origin of Deposits of Phosphate of 
 Lime," Bulletin oj tie V.8. Geol. Survey, A 7 o. 46. Washington, 1888, p. 60. 
 
MODE OF OCCURRENCE OF MINERALS. 69 
 
 horse and other land animals. The deposit is considered to be of 
 Post-Pliocene age. 
 
 The existence of valuable deposits of phosphate in Florida* 
 was not known till 1887. There are four different kinds 
 of the fertiliser (i) "hard rock" phosphate, (2) "soft" 
 phosphate, (3) " land pebble " phosphate, (4) " river pebble " 
 phosphate. 
 
 The "hard rock" is a hard, massive, light grey phosphate of 
 lime, with cavities lined with secondary mammillary incrustations 
 of the mineral. It has been produced by the alteration of 
 Eocene and Miocene limestone, and yields about 36 or 37 per 
 cent, of phosphoric anhydride (P 2 5 ), 
 
 The "soft" phosphate includes material resulting from the 
 disintegration of the hard phosphate, and also highly phosphatic 
 sands and clays, rarely averaging more than 2 2 per cent, of phos- 
 phoric anhydride. 
 
 The " land pebble '' phosphate is made up of pebbles of various 
 sizes, up to that of a walnut. They consist of an earthy material 
 carrying pisolitic grains of phosphate of lime, or of a substance 
 resembling the hard rock phosphate. The percentage of phos- 
 phoric anhydride is about 32. 
 
 The "river pebble" phosphate is found in the beds of the 
 present rivers, and also in their ancient channels. The pebbles 
 are blue, black, and grey in colour, and contain the bones and 
 teeth of various animals. They yield from 20 to 28 per cent, of 
 phosphoric anhydride. 
 
 The phosphate of lime worked at Aruba and Sombrero, in the 
 "West Indies, was originally a coral limestone ; its conversion 
 into phosphate has been effected by the percolation of water 
 containing phosphoric acid derived from the dung of sea-fowl. 
 This interesting fact is made very plain by finding corals 
 themselves changed into phosphate of lime. In the island of 
 Redonda, owing to a difference in the rocks acted on by the 
 drainage from the excrement, the mineral produced is phosphate 
 of alumina. 
 
 Potassium Salts. The deposits of various potassium salts at 
 Stassfurt belong to the Bunter Sandstone formation of the 
 Magdeburg-Hal berstadt basin, and workings have now shown 
 that they attain a thickness of very nearly 3000 feet (900 
 metres). 
 
 The beds may be divided according to their chemical com- 
 position into four regions,f which in descending order are : 
 
 * Eldridge, "A Preliminary Sketch of the Phosphates of Florida," 
 Tram. Amer. Inst. M.E., vol. xxi. (1892), p. 196. Wyatt, The Phosphates 
 of America. New York, 1891. 
 
 t Fuhrer zum vierten Lergmannstay, 1889. Halle a. d. Saale, 1889, p. 
 xxxiv. 
 
70 ORE AND STONE-MINING. 
 
 APPROXIMATE THICKNESS. . 
 Feet. Metres. 
 
 4. Carnallite region. Carnallite is the double 
 
 chloride of potassium and magnesium 
 
 (KC1, MgCl 2 + 6H 2 0) 82 25 
 
 3. Kieserite region. Rock salt with beds of 
 
 kieserite (MgSO 4 + H 2 O) . . ^. .183 56 
 
 2. Polyhalite region. Rock salt with strings of 
 
 polyhalite (K 2 S0 4 , MgS0 4 , 2CaSO 4 ,+2H 2 0) 197 60 
 
 I. Rock-salt. An exceedingly thick bed. 
 
 As is shown by the section (Fig 62), the edge of the carnallite 
 region consists of kainite (K 2 S0 4 , MgS0 4 , MgCl 2 +6H 2 0); this 
 
 FIG. 62. 
 
 a, Older rock salt ; 6, polyhalite region ; c, kieserite region ; 
 d, carnallite ; e, saliferous clay ; /, kainite ; g, sylvinite ; h, gyp- 
 sum and anhydrite ; i, younger rock salt ; j, gypsum ; k, k, varie- 
 gated marls with thin beds of limestone and of oolite ; I, diluvium 
 and alluvium. The depths marked are in metres. 
 
 is considered to be of secondary origin, and so also is regarded 
 the sylvinite, a mixture of potassium and sodium chlorides with 
 their sulphates, which occurs in workable quantities. 
 
 Above the potassium salts is a bed of saliferous clay 26 feet (8 m.) 
 thick, and then 290 feet (90 m.) of anhydrite, which forms the floor 
 of the Bunter beds. At several places there is a younger bed 
 of rock-salt from 130 to 400 feet (40 to 120 m.) thick. 
 
 Hock-salt is worked to a small extent, but the potassium salts, 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 especially carnallite and kainite. are the main objects of the 
 mining.* 
 
 Quicksilver. The principal quicksilver producing mines at 
 the present time are Almaden, in Spain, Idria, in Carniola, and 
 New Almaden, in California. There are also several other mines 
 in California, and workings of some importance in Russia and 
 Italy. Peru was at one time remarkable for its quicksilver 
 deposits at Huancavelica, but these are no longer worked. China 
 possesses some little-known mines in the province of Kwei-Chau. 
 
 The relative importance to the world of the principal deposits 
 is shown by the following table, taken from Mr. Becker's mono- 
 graph .f 
 
 PRODUCT OF THE PHTNCIPAL DISTRICTS, IN SPANISH FLASKS OF 
 75 SPANISH POUNDS, OR 34*507 KILOGRAMMES. 
 
 
 -1 
 
 
 
 Up to 
 1700. 
 
 1700 to 
 1800. 
 
 1800 to 
 1850. 
 
 1850 to 
 
 1886. 
 
 Total to 
 Jan. 1886. 
 
 Almaden . . 
 Idria 
 
 Year 
 1564 
 
 I s2^ 
 
 517,684 
 
 OQQ 36l 
 
 1,221,477 
 
 608 74.7 
 
 1,091,075 
 
 1.135,576 
 
 OQI C4.Q 
 
 3,965,812 
 
 I CC2 77Q 
 
 Huancavelica . 
 California . . 
 
 1571 
 1850 
 
 881,867 
 
 543.642 
 
 75.604 
 
 1,429,346 
 
 1,501,113 
 1,429,346 
 
 
 
 1,799,412 
 
 2,373,862 
 
 1,408,905 
 
 2,866,471 
 
 8,448,650 
 
 Mr. Becker has brought together a vast array of useful facts 
 concerning the occurrence of quicksilver in his valuable mono- 
 graph, which may be very briefly summed up as follows : J 
 Cinnabar is found in rocks of all ages and of all descriptions, 
 viz., conglomerate, sandstone, quartzite, limestone, shale, 
 slate, serpentine, crystalline schist, and basic and acidic 
 volcanic rocks, but it exhibits a preference for sand- 
 stone. The quicksilver deposits are found along lines of country 
 marked by past or present volcanic disturbances. This fact is 
 made very plain by a map of the world on which are indicated 
 all important occurrences of the metal. 
 
 Some cinnabar has certainly been precipitated from hot solutions 
 brought up by volcanic springs, and it seems likely that many 
 of the quicksilver deposits have been formed in this manner. || 
 
 The cinnabar is often found filling up interstitial spaces of 
 the rock, and if the rock is sedimentary it sometimes cuts across 
 the planes of stratification, and sometimes runs parallel to them. 
 
 * Precht, Die Sah-Industrie von Stassfurt und Umyegend. 4th edition, 
 Stassfurt, 1889. 
 
 t Becker, " Geology of the Quicksilver Deposits of the Pacific Slope," 
 Monographs of U. & Geol. tiurvet/, vol. xiii. Washington, 1888, p. 7. 
 
 Ibid. p. 50. Ibid. p. 15. || Ibid. p. 55. 
 
72 OIIE AND STONE-MINING. 
 
 Spain. The famous and productive Almaden mine is situated 
 on the northern slope of the Sierra Morena, where the rocks 
 coming up to the surface are of Silurian and Devonian age. 
 These rocks are beds of sandstone and quartzite interstratified 
 with slate and a little limestone. The cinnabar occurs impregnat- 
 ing the sandstone ; the slate is rarely, if ever, quicksilver- bearing. 
 There are three principal deposits extending for a distance of 200 
 to 220 yards (180 to 200 m.) along the strike, the dip is almost 
 vertical. The total useful thickness of the three beds is reckoned 
 to be 40 feet (12 m.), and the mercurial rock yields on an average 
 10 per cent, of metal. It seems probable that these sandstone 
 beds were impregnated by aqueous solutions which came up from 
 below. They may be called veins or beds according to the defini- 
 tions one chooses to adopt for a vein. No doubt the cinnabar is 
 of subsequent origin to the main part of the stratum. ; but the 
 same may be said for the copper in the conglomerate beds of Lake 
 Superior, and possibly for the gold in the " banket " of South 
 Africa. The quicksilver solutions deposited their metal in 
 cavities existing between the particles composing the sand- 
 stone, and I think in a case of this kind, where more than 
 90 per cent, of the deposit is matter of detrital origin, it is most 
 convenient to speak of the deposits as beds. However, in two of 
 the mercurial strata there are little strings and seams, either 
 parallel to the bedding or crossing the planes of stratification in all 
 directions. Looked at on a small scale, these strings could be 
 called veins, but when one has to deal with the workable stratum 
 as a whole it may be called a bed. 
 
 Austria. At Idria, in Carniola,* cinnabar occurs in theTriassic 
 
 FIG. 63. 
 
 A, compact sandstone ; B, less compact sandstone impregnated 
 wiih cinnabar 13 to 16 feet (4 to 5 m.) thick ; C, shale ; D, thinly- 
 bedded sandstone. 
 
 rocks in three ways : (i) impregnating beds of shale, conglomerate 
 and dolomitic breccia ; (2) filling up of cracks like ordinary fissure 
 veins ; (3) in irregular veins across the mass, making a stock- 
 work. Lipold supposes that it was introduced by watery solu- 
 tions in late Tertiary times. 
 
 * Das k. k. QuccksilbtrwcrJc zu Idria in Krain. Vienna, iSSi. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 73 
 
 FIG. 64, 
 
 Russia. An interesting and important deposit is being worked 
 at Ekaterinoslav in Southern Russia, a section of which is given 
 in Fig. 63. The cinnabar is disseminated through a sandstone, 
 which lies between another bed of sandstone of a more compact 
 nature and a bed of shale. Once more we have a case in which 
 the mercurial solutions made their way upwards along the easiest 
 channels they could find. 
 
 California. The quicksilver deposits of California* are found 
 in various parts of the State, from the extreme north to Los 
 Angeles. The most important mine is New Almaden, situated 
 about fifty miles to the S.E. of San Francisco. 
 
 In California, as in Austria, the deposits of cinnabar are of 
 several types, even at one and the same mine. Thus, at New 
 Almaden the commonest kind of 
 ore-body is a network of veins and 
 veinlets through the rock, in fact a 
 stockwork. If the disturbance pro- 
 duced a clean fissure instead of a 
 multitude of irregular cracks, then 
 the single rent was filled up and 
 produced what some would call a 
 typical vein. Lastly, if the mercu- 
 rial solutions traversed beds of sand- 
 stone, they deposited some of their 
 contents in the interstitial spaces 
 between the grains, and so formed 
 an ore-bearing stratum. All three 
 kinds of ore-bodies were formed by 
 the same process of deposition, the 
 difference, if I may use the simile, 
 depending upon the lodgings that 
 happened to be vacant, and not upon 
 the lodger who came to take up his 
 abode there, nor upon the vehicle 
 that brought him to his new home. 
 
 The ore- bodies at New Almaden 
 
 occur close to faults filled with clay and fragments of rock, more 
 or less rounded by the attrition produced by movements of the 
 "country." The name given to these faults by the miner is 
 " altas," a Spanish term referring to their usual position on the 
 hanging side of the deposit. It seems as if the impermeable 
 clay had arrested and directed the course of the ore-bearing solu- 
 tion as it ascended ; this is highly probable, and it is an explana- 
 tion which has been offered in many cases when the ores of other 
 metals have been found to " make up against a slide." 
 
 The surrounding rocks at New Almaden are metamorphosed 
 
 * Becker, op. eit. p. 317. 
 
74 
 
 ORE AND STONE.MINING. 
 
 sediments of Neocomian age, pseudodiorite, pseudodiabase, 
 phthanites, sandstone, shale, and serpentine. The minerals 
 accompanying the cinnabar are iron pyrites, marcasite, quartz, 
 calcite, dolomite, magnesite, and rarely chalcopyrite. 
 
 The deposit worked at Great Western mine, 70 miles north of 
 San Francisco, is a tabular reticulated mass of rock (Fig. 64),* 
 impregnated with cinnabar and a little native quicksilver. It 
 lies between serpentine and a very slightly altered Neocomian 
 sandstone. The serpentine is accompanied by a belt of black 
 opaline rock, called the "quicksilver rock" by the miners. The 
 
 FIG. 65. 
 
 SCALE OF FEET. 
 
 longitudinal section (Fig. 65) explains that the ore-bodies are 
 separated by spaces of barren ground, just as they are in an 
 ordinary lode. 
 
 The Sulphur Bank mine is of interest because the solfataric 
 action, which no doubt caused the deposition of the cinnabar, is 
 still going on. At first the surface was worked for sulphur, 
 which had been formed by deposition from sulphuretted hydrogen 
 escaping through basalt, just as it does in so many places in the 
 other volcanic areas. A few yards below the surface, the sulphur 
 proved to be cinnabar- bearing, and lower down cinnabar was 
 found in large quantities. 
 
 Cinnabar has since been worked from the strata underlying 
 the basalt. There are beds of shale and sandstone of Neocomian 
 age, in which the quicksilver ore is found as impregnations and 
 irregular seams. The ore is accompanied by quartz, opal, iron 
 pyrites, calcite, bitumen, and marcasite. This last mineral con- 
 tains small quantities of gold and copper. Hot springs are common 
 
 * Becker, op. cit. p. 36 
 
MODE OF OCCURRENCE OF MINERALS. 75 
 
 in the mine, and many of them give off gases, viz., carbon dioxide, 
 sulphuretted hydrogen, marsh gas, nitrogen and ammonia. 
 
 Nevada. From a scientific point of view, one of the most in- 
 teresting mineral deposits in the United States is that of Steam- 
 boat Springs in Nevada, only six miles from the Comstock lode. 
 A number of hot springs exist along a series of fissures about a 
 mile in length ; siliceous sinter is being deposited by them, and 
 there are also mounds of sinter formed by springs that are no 
 longer flowing, or whose only sign of activity consists in emana- 
 tions of steam, sulphuretted hydrogen, carbonic anhydride, and 
 sulphurous anhydride. These solfataric gases also escape with 
 the water at some of the living springs. 
 
 The sinter is found on analysis to contain many of the heavy 
 metals, viz., antimony, arsenic, cobalt, copper, gold, iron, lead, 
 manganese, mercury, silver, and zinc, some of them certainly 
 existing in the form of sulphides. 
 
 A sample of the water taken from a spring with a temperature 
 varying from 167 to 184 Fahr. (75 to 84.5 C.) was analysed; it 
 showed weighable quantities of arsenic and antimony, and a trace 
 of mercury ; as it cooled it could be seen to deposit the sulphides 
 of antimony and arsenic together with silica. 
 
 In one part of the district, instead of sinter, a deposit like that 
 at Sulphur Bank, consisting of sulphur and cinnabar, has been 
 formed ; and it has been worked for the commercial extraction of 
 mercury. 
 
 Salt. Sea water, salt lakes, JDrine springs and wells, sali- 
 ferous marls and rock-salt are the sources of this very important 
 mineral. 
 
 The extraction of salt from sea-water is carried on in Southern 
 Europe and other countries, where the heat of the sun is sufficient 
 to evaporate the water which has been led into shallow ponds ; and 
 the industry is fostered in many cases by the traffic in salt being 
 a Government monopoly. 
 
 In South Africa and elsewhere salt is obtained from "pans" or 
 shallow inland lakes, which become partially dried up in the hot 
 season. 
 
 Natural springs yielding brine are not uncommon, and brine 
 wells are dug or bored so as to reach a salt-bearing stratum. 
 
 At Northwich,* in Cheshire, there are two main beds of rock- 
 salt, each from 84 to 90 feet thick, separated by a bed of hard 
 marl 30 to 33 feet thick. All these beds belong to the Keuper 
 division of the Triassic rocks. The amount of rock-salt mined in 
 England is small, only about one-tenth of that obtained from 
 brine, which is pumped from flooded mines, and from wells or 
 boreholes penetrating saliferous strata. 
 
 * Dickinson, "Report on the Salt Districts," Rcporis of the Inspectors of 
 Mines for the Year 1881, p. 55. 
 
76 OHE AND STONE-MINING. 
 
 Silver. All galena carries some silver, and in very many cases 
 there is enough to make the extraction profitable. Copper ores 
 also are frequently argentiferous : the silver in the Mansfeld 
 cupriferous shale has already been mentioned, and the ores 
 of the Butte district, Montana, are often rich in the precious 
 metal ; it is needless, however, to dwell upon this and similar 
 sources of silver, though they are of great commercial importance. 
 Among well-known silver mines may be mentioned those of the 
 great Comstock Lode in Nevada, the Eureka and Richmond 
 mines in the same State, Huanchaca in Bolivia, and Broken Hill 
 in New South Wales. 
 
 Comstock Lode. This remarkable lode strikes about north and 
 south and dips about 43 to the east. The vein, which is usually 
 from 20 to 60 feet thick and as much as several hundred feet thick 
 in some places, consists in the main of crushed and decomposed 
 portions of the " country " together with clay and quartz. The sur- 
 rounding rocks are syenite and propylite, according to King,* or 
 diorite and diabase, according to Becker."}* The latter says that the 
 so-called propylite is only a decomposed form of other rocks. The 
 silver is found native and in the form of silver glance, polybasite, 
 stephanite, and occasionally pyrargyrite ; other minerals in the 
 vein are quartz, iron pyrites, copper pyrites, besides oxides of iron 
 and manganese, sulphates of calcium and magnesium and car- 
 bonates of magnesium, calcium, lead and copper. The ore-bodies 
 are soft and irregular. 
 
 The heat of the Comstock lode is noteworthy. In the 2700 
 feet level of the Yellow Jacket mine, Mr. Becker found the temper- 
 ature of the water to be 153 Fahr. and that of the air 126 Fahr., 
 whilst the water of the Yellow Jacket shaft at a depth of 3065 
 feet had a temperature of 170 Fahr. 
 
 Eureka-Richmond. The nature of the curious lode worked at 
 the Eureka-Richmond .t mines will be best understood by reference 
 to Fig. 66 ; much of it is a mass of crushed limestone of Cambrian 
 age lying between two faults, a main one dipping N.E. at an 
 angle of 70, and a secondary one which is much flatter. 
 
 The main fault is a fissure filled with clay or with decomposed 
 rhyolite and clay, varying from a few inches to 15 feet in width. 
 It shifts the rocks many hundreds of feet, and at Eureka the 
 throw exceeds 1400 feet. The valuable parts of the lode are ore- 
 bodies of every possible shape and size, some measuring upwards 
 of 100 feet in all directions. Above the water level, or horizon 
 of decomposition by atmospheric agencies, the minerals constitut- 
 
 * King and Hague, " Mining Industry," U. S. Geol. Exploration of the 
 Fortieth Parallel. Washington, 1870. 
 
 t " Geology of the Comstock Lode and Washoe District," Monograph 
 111. of U. S. Geol. Survey. Washington, 1882. 
 
 + Curtis, "The Silver-lead Deposits of E'ireka, Nevada," Monograph 
 V1I1. of U. S. Geol tiurvey. Washington, 1884. 
 
MODE OF OCCURRENCE OF MINERALS. 
 
 77 
 
 ing the ore-bodies, are galena, cerussite, mimetite, wulfenite, 
 with very little quartz and calcite, the remainder of the veinstuff 
 being mainly hydrated oxide of iron carrying silver and gold, 
 with some carbonate and silicate of zinc. Below the water level 
 the minerals are pyrites, arsenical pyrites, galena, blende and a 
 few other sulphides, besides silver and gold. One of the char- 
 
 FIG. 66. 
 
 F^ioo o 
 
 SCALE OF FEET 
 
 200 400 600 800 
 
 1000 
 
 100 
 
 METRIC SCALE 
 
 
 
 200 M. 
 
 H. Ore. 
 
 G. Hamburg Limestone. 
 
 F. Secret Canon Shale. 
 
 E. Stratified Limestone.^ 
 
 D. Limestone, 
 
 C. Shale. 
 
 B. Crushed Limestone. 
 
 A. Prospect Mountain Quartzite. 
 
 Prospect Mountain Limestone. 
 
 acteristics of the ore is the presence in it of gold in paying 
 quantities. It is considered by Mr. Curtis that an eruption of 
 rhyolite caused the upheaval which made the main fault in Ruby 
 Hill ; this eruption occurred in the Tertiary period. It is sup- 
 posed that solfataric action decomposed some massive rock and so 
 formed metalliferous solutions, which ascended and, penetrating 
 into the limestone, deposited the oie. Some of the ore is pro- 
 bably pseudomorphous after limestone. The average contents of 
 all the Richmond ore worked in 1879 were : 
 
 Lead 
 
 Silver 
 
 Gold 
 
 Iron 
 
 33 per cent. 
 
 274 oz. per ton (2000 Ib.) 
 
 i 59 oz. 
 
 24 per cent, corresponding to 34 
 per cent, of Fe.p 8 . 
 
78 OHE AND STONE-MINING. 
 
 Huancliaca. The mines of Huanchaca are situated near the 
 town of that name in the department of Potosi in Bolivia, at a 
 great altitude, for the entrance of the San Leon adit is 13,500 feet 
 above the level of the sea. The silver lodes occur in a soft de- 
 composed trachyte; the actual silver-bearing mineral is fahlerz, 
 containing about 10 per cent, of the precious metal. Fortunately 
 for the shareholders the percentage of silver increases with the 
 depth of the mine. The accompanying minerals are galena, 
 blende, iron pyrites, copper pyrites, with heavy spar and quartz, 
 and rarely a little stibnite and pyrargyrite. The main lode runs 
 about east and west, and is from 3 to 10 feet in width (i to 
 3 metres); it has three particularly rich shoots which incline 
 from west to east. The total output of silver in 1887 was 
 4,214,510 oz. (131,086 kil.). 
 
 At the famous Potosi mines also, the silver occurs in a fahlerz. 
 
 Broken Hill. The mines at Broken Hill are remarkable for their 
 enormous output of silver and lead during the last few years. 
 They are situated in the Silverton or Barrier Ranges district of 
 New South Wales, near the western boundary of the colony. The 
 deposit is generally spoken of as a vein or lode, but there seems 
 some doubt whether this appellation is correct ; further develop- 
 'ments of the workings may prove that it is a bed. The vein, if it 
 may be so called, runs, roughly speaking, N.E. and S.W. ; the dip 
 varies, being sometimes to the S.E. and sometimes to.N.W., and 
 is always steep. At and near the surface, the vein * consisted of 
 dark-brown haematite, often blackened by psilomelane, together 
 with ferruginous carbonate of lead, kaolin, and the chloride, chloro- 
 bromide and iodide of silver ; besides these there were pyromorphite, 
 atacamite, cuprite, malachite, and chrysocolla, with quartz, 
 quartzite, and garnet rock. Below this upper weathered zone, 
 containing minerals usually met with in gozzans, come the 
 sulphides, especially galena and zinc blende, together with pyrites, 
 chalcopyrite, and mispickel. Some of the galena is so intimately 
 mixed with the blende as to render its separation by any ordinary 
 dressing process very difficult, if not commercially impossible. 
 Ores of this class f contain 15 to 40 per cent, of lead, 15 to 30 
 per cent, of zinc, and 8 to 24 ounces of silver to the ton, and at 
 present the owners of the mines have not settled what method of 
 treatment will prove the most efficacious and economical. The 
 width of the lode is from 15 to 316 feet. The enclosing rocks are 
 gneiss and garnetiferous mica and talcose schists, and the vein lies 
 
 * John Provis, " Report on the Broken Hill Proprietary Co.'s Mines," 
 contained in the Company's Reports and Statements of Accounts for the Half 
 Year ended Nov. 30^, 1886. Melbourne, Victoria. Jamieson and 
 Howell, "Mining and Ore-treatment at Broken Hill, N.S.W.," Proc. Inst. 
 C.E., vol. cxiv. (1892-93), Part IV. 
 
 t Schnabel, "Vorschlage zur Verarbeitnng australischer silberhaltiger 
 Blende-Bleiglanzerze," B. u. h. Z., 1882, p. 429. 
 
MODE OF OCCURRENCE OF MINERALS. 79 
 
 parallel to the planes of foliation. In the seven years ending 
 3ist May, 1892,* the principal mine, owned by the Broken Hill 
 Proprietary Company, produced 984,349 tons of ore, which yielded 
 36,512,445 ounces of silver and 151,945 tons of lead, worth 
 altogether ,8,252,138, of which ^3,896,000 has been paid in 
 dividends and bonus. 
 
 Silver-bearing Sandstone. Silver is found in workable 
 quantities in certain beds of sandstone, interstratified with shale, 
 considered to be of Triassic age, at Stormont in Southern TJtah.f 
 All the strata contain at least some traces of silver, but 
 three or four special horizons were rich enough to be worked ; 
 even here the precious metal was distributed irregularly, and 
 mining was confined to rich " shoots " or chimneys, which some- 
 times followed one particular stratum of the general ore-bearing 
 bed, and sometimes cut across it. It is supposed that silver- 
 bearing solutions came up through the rock, and flowed along 
 the portions which they found most porous. The precipitation 
 of the silver was, perhaps, caused by the presence of organic 
 matter. The metal exists in the form of sulphide and chloride, 
 though there is a little native silver. These minerals are dissemi- 
 nated through the sandstone, and occur especially along the 
 planes of bedding and of fracture. The ore-beds were mined for 
 a thickness of six, eight, or even ten feet, though the whole of 
 the rock was not always worth milling. Much of the ore milled 
 about 1879 contained from 20 to 30 oz. of silver per ton, and 
 yielded by amalgamation 15 to 24 oz.l 
 
 Garfield Mine, near Calico, California, owes its existence to a 
 network deposit or stockwork. The surrounding rock is liparite 
 or rhyolite, which is traversed near by a number of irregular 
 fissures. The cracks contain kerargyrite and embolite, with chry- 
 socolla and heavy spar, and the stockwork may be described as a 
 breccia of liparite cemented by the argentiferous and other 
 minerals. 
 
 Slate. Wales is so renowned for its slate that the example of 
 a deposit of this mineral may fairly be taken from the Principality. 
 About two-thirds of the Welsh slate are got from beds of Cambrian 
 age in Carnarvonshire, and one-third from beds in the Lower 
 Silurian (Ordovician) rocks in Merionethshire. The quarries in 
 the former county are mostly open, whilst in the latter the local 
 conditions have led to the adoption of true mining, especially at 
 Festiniog, which can boast of the most extensive underground 
 
 * Company's Half- Yearly Report, dated July 27, 1892, p. 86. 
 
 t E. P. Kothwell, "Keport on the Stormont Silver Mining Company's 
 Property, Silver Reef." Utah, 1879. 
 
 J Jackson, " Silver in Sedimentary Rocks," Report of the Directors of He 
 U.S. Mint. Washington, i88r, p. 384. 
 
 W. Lindgren, "The Silver Mines of Calico, California," Trans. Amer. 
 Inst. M.E., vol. xv. (1^86-87) p. 725. 
 
So ORE AND STONE-MINING. 
 
 workings for slate in the world. The northern part of the parish 
 of Festiniog is occupied by the outcrop of a thick series of slaty 
 rocks (K, Fig. 67*), resting upon coarse volcanic agglomerate, H, 
 and interstratified with thinner beds of volcanic ash, and inter- 
 iSected from time to time by intrusive dykes of diabase, locally 
 called whinstone. The beds have a general northerly or north- 
 westerly dip of 20 to 35, whilst the cleavage planes throughout 
 the district dip at a greater angle than the bedding by about 15, 
 and very nearly in the same direction. 
 
 Owing to peculiarities of texture, due apparently to the fineness 
 of the sediment deposited upon the old sea-bottom, certain beds 
 or sets of beds furnish a slate which can be split into very smooth 
 sheets, as thin as T X F inch and even less. Any set of beds worked 
 as a whole is known locally as a " vein," but it does not necessarily 
 furnish saleable roofing material for its entire thickness. Some- 
 
 Dolwen. Foci. Foel Rydd. 
 
 G-F* 
 
 A, granite ; B, Tremadoc rocks ; C, Garth Grit ; D, Lower Slate ; 
 E, Arenig rocks above the grit ; F, Lower Agglomerate; F', Middle 
 Agglomerate ; G', Middle Slate; G, Upper Slate ; H, Upper Agglomer- 
 ate ; K, Llandeilo slates. 
 
 times unpiofitable rock is taken away above the good slate in 
 order to reach a firm layer, such as a bed of volcanic ash, or a 
 " whinstone " dyke, which can be trusted to stand as the roof of 
 the underground chambers, and at others the fine-grained slate 
 has beds of coarser sediment interstratified with it, which cause 
 irregularities in the planes of cleavage, and so give rise to inferior 
 products. 
 
 The " Old Vein," famous for the quality of its slates, is 120 feet 
 (36.5 m.) thick at the Oakeley quarries, where other " veins " of 
 less importance are also being worked (Fig. 68). At some of the 
 other quarries of the district, beds of slate in the underlying 
 rocks of the Arenig series are found to be profitable, such as G' 
 in Fig. 67, and i in Fig. 68. 
 
 The property possessed by the slate of rending along planes, 
 cutting across both dip and cleavage, must not be forgotten, for 
 upon it depend both the getting of the rock and the direction 
 given to the supporting pillars. At the Oakeley quarries the "line 
 
 * Jennings and Williams, " Manod and the Moalwyns," Q. J. Oeol. Soc. 
 vol. xlvii. (1891), p. 368. 
 
MODE OF OCCURRENCE OF MINERALS 
 
 8r 
 
 of pillaring," that is to say, the direction along which the cross - 
 rending or rifting takes place most readily, runs about N. 7 W., 
 whereas the dip is N. 40 W. The planes along which the slate 
 rends or " pillars " best are at right angles to the cleavage planes, 
 not quite vertical, but dipping at a high angle to the east; the 
 consequence is that the eastern side of an underground chamber 
 at these quarries overhangs slightly. 
 
 The value of a slate bed, or " vein," depends greatly upon the 
 number and nature of the natural joints by which it is intersected. 
 If they are very numerous, the workings will yield blocks too 
 small for making the larger and higher priced sizes of slates ; if 
 they are rare, more expense will be incurred in severing the 
 material from its bed. Disturbances of the strata resulting in 
 
 FIG. 68. 
 SECTION OF THE OAKELBY QUARRIES, FESTISIOG.* 
 
 ^s 
 
 v>.^_- ^ 
 
 s^fe^s 
 
 *f* 
 
 Ag 1 , Ag 2 , Ag, volcanic agglomerates ; I, slate vein worked at 
 Wrysgan and New Quarry, Diphwys ; 2, new or south vein ; 3, 
 old vein ; 4, 2A vein ; 5, back vein ; 6, north vein ; WD, " whin- 
 stone" dykes (diabase); P, porphyrite ; As, volcanic ash. 
 
 fissures filled either mechanically with clay and broken slate, or 
 chemically by the deposition of quartz, may render the " vein " 
 utterly worthless in places ; but, as in the case of other bedded 
 deposits, changes in productiveness are far less frequent than 
 with lodes. 
 
 Sulphur. The industrial sources of sulphur are : (i) deposits 
 of native sulphur, and (2) iron pyrites. 
 
 Native sulphur occurs as a product of volcanic emanations, and 
 in sedimentary deposits. 
 
 The amount of sulphur obtained from deposits of volcanic 
 origin is small ; but this mode of occurrence is of geological 
 interest, because we can observe the processes of accumulation in 
 actual operation, whereas usually the secrets of Nature's laboratory 
 are hidden from us. 
 
 * Made by Mr. G. J. Williams, F.G.S. 
 
82 
 
 ORE AND STONE-MINING. 
 
 Fin. 69. 
 
 Deposits of this kind are generally found at or near spent vol- 
 canic craters, the emanation of sulphurous gases being one of their 
 last signs of activity. Sulphur has been worked on a small scale 
 
 at the famous Solfatara of 
 Pozzuoli, near Naples, at 
 Yulcano, one of the Lipari 
 Islands, and in volcanic re- 
 gions in various parts of the 
 world. 
 
 In Iceland a little column 
 of vapour may be seen issu- 
 ing from the ground, and the 
 low mound around it con- 
 
 *% 
 
 ta 
 
 -Vf 5^ 
 
 < 1 r 
 
 covered by a thin coating of 
 blown sand. The gases com- 
 ing out of the earth contain 
 sulphuretted hydrogen in 
 addition to steam, and 
 when they reach the surface some of the former is oxidised, 
 and sulphur is deposited as shown in Fig. 69 ; a is the under- 
 lying rock, a decomposed lava, b clay, c the native sulphur, 
 and d sand blown over the little mound, and retained by the 
 moisture due to condensation of the steam. I have already alluded 
 to Sulphur Bank and Steamboat Springs, in speaking of quick- 
 silver. 
 
 Seams or beds of sulphur occur in Sicily, Calabria, the Romagna, 
 and other parts of Italy, and also in Croatia, Spain, and France. 
 By far the most important beds are those of Sicily. 
 
 The accompanying section, borrowed from Baldacci* (Fig. 70), 
 shows a section of the country near Caltagirone. The letter a 
 
 FIG. 70. 
 
 
 denotes beds of clay (Tortonian), b is tripoli (Sarmatian), c is the bed 
 of sulphur-bearing limestone, d white marl or marly limestone with 
 foraminifera, called " trubi " in Sicily ; e, blue clay ; /, calcareous 
 tufa. The beds a, 6, c are considered to belong to the Upper 
 Miocene, whilst d is placed in the Lower Pliocene, and e and fin. 
 the Upper Pliocene. 
 
 The beds of tripoli are made up chiefly of the siliceous remains 
 of radiolaria, diatomaceae, and sponges, together with marl. 
 
 * Descrizione geologica dell' Isola di Sicilia. Rome, 1886, p. 296. 
 
MODE OF OCCURRENCE OF MINERALS. 83 
 
 The sulphur-bearing bed varies from a hard white limestone 
 to a grey marly limestone, and from this to a marl ; the sulphur 
 itself is always in the native state, forming little globules, laminse, 
 or irregular lenses, varying in thickness and extent. It is often 
 crystallised, and associated with it are celestine, gypsum, calcite, 
 and arragonite ; in the clayey beds there is also bitumen, which 
 is objectionable, as it gives a dark colour to the product obtained 
 by liquation. 
 
 The thickness of the sulphur seams varies within very wide 
 limits. Beds 20 'feet thick are common, and at Lercara the 
 stratum reaches the enormous thickness of 164 feet (50 m.). 
 Frequently there are two or three beds ; at the great Somatino 
 mine, for instance, the deposit is 100 to 115 feet (30 to 35 m.) 
 thick, divided into six separate seams, from 6 to 25 feet (2 to 8 m.) 
 each, by partings of barren rock. 
 
 As a rule, a bed less than 5 feet (1.50 m.) in thickness is not 
 worth working, unless it is exceptionally rich or conveniently 
 situated for working. 
 
 The yield of the sulphur rock may be taken on an average at 
 about 22 per cent., though occasional rich seams give as much as 
 45 per cent. 
 
 Parodi* subdivides the seams according to quality, thus : 
 
 Amount of Sulphur. 
 
 By Analysis. Actual Yield by the Kilns. 
 
 Per cent. Per cent. 
 
 Very rich . . . . 30 to 40 20 to 25 
 
 Kich 25 30 15 20 
 
 Poor 15 25 10 15 
 
 The Sicilian deposits are considered to have been formed by 
 chemical precipitation from aqueous solutions in lakes.f 
 
 The deposits on the Italian mainland also belong to the Miocene 
 period, and the sulphur beds are known to extend for a long 
 distance on the east of the Apennines. Often there is but one 
 seam 6 to 10 feet (2 to 3 m.) thick ; the rock is poorer than in 
 Sicily, for it contains only 18 to 20 per cent., and the yield by 
 the kiln (calcarone) does not exceed 1 2 per cent, on an average. 
 
 After the description of the deposits of cupreous pyrites at 
 Rio Tinto, it is quite unnecessary to say anything further about 
 such sources of sulphur. Iron pyrites containing no copper is 
 sometimes worked, and Cae Coch Mine, in Carnarvonshire, 
 affords an example of a deposit of this kind. 
 
 Tin. Tin ore is obtained from veins, beds, and a variety of 
 irregular deposits. 
 
 It is natural for an Englishman to take his illustrations of 
 
 * KuW estrazione dello Solfo in Sicilia. Florence, 1873, P- IO * 
 
 "Noizie sulle condizioni dell' industria solfifera e di quelle ad essa 
 affini," Rivista dd servizio miner ario nel iSSS. Florence, 1890, p. clxv. 
 
8 4 
 
 OHE AND STONE-MIMING. 
 
 veins from Cornwall. Figs. 71 and 72 represent two veins in the 
 parish of St. Agnes.* 
 
 FIG. 71. 
 
 FIG. 72. 
 
 BCD 
 
 A, slate (kiUas) ; B, cqpeZ that is to 
 say, slate altered into a hard dark- 
 coloured mass of quartz and schorl 
 with short lenticular veins of quartz, 
 and traversed by little strings of cas- 
 siterite and chlorite ; CO, the leader, 
 consisting of quartz, cassiterite, chlo- 
 rite, a little iron pyrites, and pieces of 
 capel. 
 
 AA, slate (kittas) ; BB, capel 
 as above ; CC, small leader or 
 vein of tinstone and quartz ; DD, 
 main leader, consisting of iron 
 pyrites, cassiterite, and chlorite, 
 containing about i\ per cent, of 
 tinstone. 
 
 Many of the veins in granite are due to the alteration of the 
 rock in the neighbourhood of fissures, as has been already 
 explained (Fig. 3). The so-called carbonas of the St. Ives district 
 are essentially masses of stanniferous schorl rock, very irregular 
 in shape and connected with a main lode by a cross joint or fissure. 
 They seem to be altered granite. 
 
 Mulberry Mine, near Bodmin (Fig. 16), has already been cited 
 as an instance of a network deposit or stockwork. 
 
 At Altenberg, in Saxony, there is a huge mass of tin-bearing 
 rock, locally known as "Zwitter" or "Zwittergestein." Von Cottaf 
 has shown by analyses that it is merely granite, which has lost 
 about 3 per cent, of silica and 2 per cent, of potash, and has 
 taken up about 4 per cent, of ferrous oxide and -J per cent, of 
 oxide of tin. It has been worked for tin during a period of 
 several centuries. 
 
 Beds containing tin ore in the form of rolled pebbles and 
 sand occur with the alluvial deposits of existing valleys in 
 many countries. The principal Cornish deposits have long 
 
 * C. Le Neve Foster, " Remarks upon some Tin Lodes in the St. Agnes 
 District," Trans. R. Geol, Soc. Cornwall, vol. ix. p. 206, 
 
 t B. von Cotta, " Die Steingruppe im Hofe der Bergakademie," Fest- 
 schrift zum hundertjahrigen Jubilaum der Konigl. /Sachs. Bergakademie zu 
 Freiberg. Dresden, 1886, p. 157. 
 
MODE OF OCCURRENCE OF MINERALS. 85 
 
 been exhausted, though as lately as 1873 tin ore was raised 
 from a bed under Restronguet Creek, a branch of Falmouth 
 Harbour (Fi#. 364). In the Malay Peninsula alluvial deposits or 
 "stream works" are yielding large quantities of ore; and New 
 South Wales is remarkable not only for its recent stanniferous 
 alluvia, but also for much older deposits, which, like the ancient 
 gold gravels, have been preserved under a covering of basalt. The 
 accompanying map (Fig. 73) shows part of Vegetable Creek, New 
 South Wales ; the stippling by the side of the creek represents 
 the tin-bearing alluvium, which has been worked by open pits. 
 The rest of the courtry is granite, except the shaded part at AB 
 
 FIG. 73- 
 
 si ik 
 
 which denotes basalt ; this flowed down an old valley and filled it 
 up entirely, as shown by the section (Fig. 74). The hard cover of 
 lava has preserved the stanniferous alluvium and the white clay 
 from denudation. Old alluvia of this description are known as 
 " deep leads." 
 
 Zinc. Zinc ore is found in veins, beds, and irregular masses. 
 
 Liiderich mine, situated near Bensberg, on the right bank of 
 the Rhine, not very far from Cologne, derives large quantities of 
 blende from a huge vein in the Devonian rocks. The actual 
 horizon is that of the " Lenneschiefer," which is classed as Middle 
 
86 
 
 OHE AND STONE-MINING. 
 
 Devonian. The rocks are slate, interstratified 
 with sandstone and slaty sandstone. The lodes 
 of the district, as a rule, run E. and W., or a 
 little north of west ; the Liiderich mine, however, 
 is an exception, for the lode strikes, roughly 
 speaking, north and south. It may be best de- 
 scribed as a zone or belt of broken and disturbed 
 rock, 40 to 50 metres wide, containing ore in 
 irregular veins and masses. The ore-bodies are 
 usually lenticular in shape, dying out gradually 
 in every direction; they sometimes consist of 
 solid blende for a width of several yards. The 
 minerals found in the lode are : blende, galena, 
 copper pyrites, iron pyrites, fahlerz, quartz and, 
 rarely, chalybite. The fahlerz is silver-bearing, 
 and the blende always contains cadmium, 
 and occasionally gallium. The total production 
 of the mine in 1890 was 8304 tons of blende 
 ready for the smelter, and 423 tons of lead ore. 
 It is therefore of more importance as a zinc 
 mine than any in this country. 
 
 The largest zinc mine in the British Isles at 
 the present time is Minera, near Wrexham. It 
 may be safely inferred from its name that it 
 was worked during the Roman occupation of the 
 country ; but the object of the mining in those 
 days, and, indeed, until quite a recent date, was 
 lead and not zinc ore. 
 
 The surrounding rocks are Carboniferous 
 Limestone and Millstone grit, and as the lode 
 is a well-marked fault, the Coal Measures are 
 met with on the downthrow side. There are 
 two principal veins running parallel to one 
 another in a general N.W. and S.E. direction, 
 and dipping steeply to the N.E. ; and where pro- 
 ductive they are nearly perpendicular. They 
 vary in size from a mere cleft in the rock to a 
 width of 1 8 feet; a fair average size is 6 feet. 
 Besides these two main veins there are numerous 
 branches and ramifications. The valuable mine- 
 rals are zinc blende and galena, and, as would 
 be expected, the matrix consists mainly of calc- 
 spar. In the upper parts of the mine to a depth 
 of 220 yards, galena was met with in large quan- 
 tities, arid the mine made considerable profits upon 
 its sales of lead ore ; but during the last twelve 
 years blende has greatly predominated. At the 
 present time it may be reckoned that the " stuff ;J 
 
MODE OF OCCURRENCE OF MINERALS. 87 
 
 brought up from the mine yields 7j percent, of blende and i J per 
 cent, of galena. The total production of the mine in 1891 was 
 5433 tons of zinc ore and 906 tons of lead ore ready for the 
 market. o 
 
 At *Ammeberg, near the northern extremity of the Wetter 
 Lake, in Sweden, zinc blende occurs in beds. The surround- 
 ing rock is a schist consisting of felspar and quartz, with a little 
 mica, which may be regarded as a variety of gneiss. The blende 
 is accompanied by iron pyrites, pyrrhotine, hornblende, chlorite, 
 garnet, tourmaline and other minerals, and in places it may be 
 plainly seen to replace the mica of the gneiss. The Ammeberg 
 beds are worked on a large scale by the Yieille Montagne 
 Company. 
 
 Diepenlinchen mine, near Stolberg, in Prussia, is interesting 
 not only on account of being a large producer of zinc ore, but also 
 because some of it is derived from a great stockwork, a form of 
 deposit less common with zinc than tin. The stockwork consists 
 of an oval mass of limestone, about 120 metres long from east to 
 west, and 50 metres across from north to south. In this region 
 the limestone is full of cracks, which have been filled up with 
 zinc blende, and this mineral is also seen lining small irregu- 
 lar cavities in the rock; judging by its structure it has been 
 deposited layer after layer, and probably from an aqueous solution. 
 The rock is so intermingled with blende that the whole of it 
 has to be worked away, and the separation of the valuable con- 
 stituent from the waste is effected by dressing. 
 
 Fig. 15 is a section across one of the irregular masses of 
 calamine at Altenberg, in the neutral territory of Moresnet, be- 
 tween Belgium and Prussia. 
 
 FAULTS. All kinds of deposits are subject not only to 
 irregularities dependent upon their mode of formation, such as a 
 gradual thinning out or thickening, 
 but to others which have taken place Fio. 75. 
 
 subsequently. Sometimes a bed, 
 such as AB, has had a portion de- 
 nuded by a current during the 
 general period of deposition. Such 
 an occurrence is called a " wash A 
 out " fault, or " dumb fault " 
 (Fig. 75). 
 
 In addition to irregularities of this kind, deposits suffer from 
 the disturbances which have taken place in the rock masses which 
 contain them. Slight undulations of the strata are common, and 
 when the disturbance has been greater, the beds are bent into 
 arches and troughs, or anticlinals and synclinals. Further, a 
 
 lS79 * V j I Groddeck Die Lehre von den Lagerstdtten der Erze. Leipsic, 
 
88 
 
 ORE AND STONE-MINING. 
 
 FIG. 76. 
 
 ^ X 
 
 lateral pressure may have been sufficient to cause great erumplings 
 and contortions, and in places to invert the order of succession, in 
 other words to make the newer beds lie under, instead of above, 
 the older ones. When beds are much bent there is often a 
 thickening in the anticlinals and synclinals, and a corresponding 
 thinning in the connecting limbs. 
 
 A bed may be so folded and crumpled as to lose its original 
 sheet-like form in places, and assume 
 the shape of an irregular mass. 
 This may happen even with a coal 
 seam.* 
 
 The disturbances of the rocks may 
 finally produce rents, accompanied by 
 displacement, which are called faults, 
 heaves, throws, or slides. 
 
 We will take the case of a bed 
 (Fig. 76). AB is a seam which ends 
 suddenly at B, whilst the continua- 
 tion is found at a lower level, CD. The two parts of the bed 
 must have originally been on the same horizon, but subsequently 
 a fracture took place along the line XY, followed by a movement 
 of one side or both sides. As a rule the portion of rock on the 
 upper or hanging wall side appears to have slid downwards, or 
 the under portion to have been thrust upwards. 
 
 The rent may be clean, sharp, and narrow, with the shifted 
 portions of rock touching each other; or there may be a sue- 
 
 FIG. 77- 
 
 FIG. 78. 
 
 cession of fissures producing a step- like arrangement of the seam 
 (Fig. 77) ', frequently the cracks are filled up with clay, or there 
 is a zone several yards in width composed of broken fragments 
 and clay, produced by the attrition of the sides of the two rock 
 masses (Fig. 78). Signs of rubbing may be seen upon the walls 
 
 J. Callon, Lectures on Mining, vol. i. p. 63, and Atlas, Plate VIII., 
 
 Fig. 44- 
 
MODE OF OCCURRENCE OF MINERALS, 89 
 
 in the form of grooves and scratches, or polished surfaces known as 
 " slickensides." A fault is of the same origin as a mineral vein ; 
 the filling is due either to mechanical or chemical agencies, or to 
 both combined, but does not happen to be worth working com- 
 mercially. The prolongation of a valuable mineral vein may 
 be unproductive on entering certain rocks, and will then be looked 
 upon as a fault. Thus, some of the 
 mineral veins of the Carboniferous FIG. 79. 
 
 Limestone in Flintshire appear to be 
 continued as faults in the Coal Measures. 
 
 The throw of a fault is measured by 
 the amount of vertical displacement. If 
 XY is a fault shifting a bed AB (Fig. 
 79), draw BE vertical and CF at right 
 angles to BE. Then BF is the vertical 
 downthrow, CF represents the horizontal 
 displacement, and BC the shift along the 
 line of dip. 
 
 The study of faults is important be- 
 cause the miner working the bed AB (Fig. 78), wants to know after 
 reaching the fault XY where to find the continuation of the de- 
 posit. The rule is to follow the greater angle. The angle ABY 
 is greater than the angle ABX, and the missing part may be 
 expected somewhere along the line BY. If the miner were work- 
 ing from D to C, the same rule would apply, for the angle DCX 
 is greater than DCY. 
 
 This rule gives the direction of the throw, but affords no indi- 
 cation as to its amount, which may 
 vary considerably. If the beds are FIG. So. 
 
 distinctly marked by lithological pe- 
 culiarities or by fossils, the miner 
 can obtain useful information by 
 driving through the fault into the 
 rocks upon the other side. Suppose, 
 for instance, that a valuable bed of 
 shale AB (Fig. 80) ended off suddenly 
 against a fault FG. A continuation 
 of the workings in the direction AB 
 comes upon a bed of conglomerate, 
 which the miner recognises as one 
 that is usually 40 feet above him. He can fairly conclude that 
 the distance BE at right angles to the prolongation of DC will 
 be 40 feet. As the respective dips of the bed and of the fault are 
 known, the angle EBC can at once be ascertained and the distance 
 BC calculated. 
 
 The throw of a fault is not always the same ; it varies along the 
 strike, and finally dies away altogether. This will be understood 
 by making a slit with a penknife through a sheet of cardboard 
 
9 o 
 
 ORE AND STONE-MINING. 
 
 or india-rubber, and pressing down one side ; the throw dimin- 
 ishes from a maximum at C to nothing at A and B (Fig. 81). 
 Change in the direction of throw may be due to the beds on 
 FIG. 81. FIG. 82. 
 
 7 
 
 one side of a fault being puckered or bent, whilst they are flat or 
 dip evenly on the other (Fig. 82). 
 
 The distance to which some faults may be traced is very great. 
 The Gorze-Ars-Metz fault* extends from St. Julien in France, 
 right across Lorraine to beyond the Saar, near Wacheren, a total 
 distance of 53 miles (85 kilometres), and another fault in the 
 same district is known for 28 miles (45 kilometres). The throw 
 of a fault varies from a few inches to hundreds and even thousands 
 of feet. 
 
 Near a fault a bed is often found to dip more steeply, as if it 
 had been bent before it broke. This is the case with the great 
 iron ore bed of Lorraine.f The usual dip is very slight, only i to 
 2 1 in a hundred, but near faults it is decidedly more, and reaches 
 4 in a hundred. 
 
 The rule that the portion of the hanging wall side has shifted 
 downwards along the dip of the fault is not without exceptions, 
 FIG. 83. FIG. 84. 
 
 especially in localities where rocks are much bent and folded. 
 Heim shows by a series of figures the various stages in the pro- 
 duction of a displacement of this kind, which is known as a 
 reversed or overlap fault (Fig. 83). Fig. 84 also shows a reversed 
 fault. 
 
 As mineral veins have been formed in regions where rocks 
 have been broken and dislocated, it is only natural to expect that 
 
 * Wandesleben, " Das Vorkommen der oolitischen Eisenerze (Minette) in 
 Lothringen, Luxemburg und dem ostlichen Frankreiche." Festschrift 
 und Verhandlungen Der IV. Allgemeine Deutsche Bcrgmannstay in Hdlle 
 (Saale.} Halle, 1890, p. 301. 
 
 t Ibid. p. 301. 
 
MODE OF OCCURRENCE OF MINERALS. 91 
 
 they also should be affected by movements and shiftings of the 
 earth's crust. Owing to the fact that veins are usually highly 
 inclined, and that there is often much difficulty in deciding how 
 the dislocated rocks fitted together before they were shifted, the 
 vein miner speaks of faults in different terms to the bed miner. 
 Instead of talking of downthrows and upthrows, he looks at the 
 shift produced sideways and calls it a 
 heave. The miner driving a horizontal 
 tunnel AB (Fig. 85) in a vein, comes 
 into the fault XY at the point B, and 
 finds that his vein ends off suddenly ; 
 in order to regain it he is obliged to 
 drive sideways in barren ground from 
 B to C, where he meets with the con- 
 tinuation along the line CD. The 
 miner says that there has been a left- 
 hand heave, because whether driving 
 in the direction A to B or D to C, 
 he finds the faulted portion to the 
 left hand. It is evident in many cases from the striations upon 
 the walls of the faults, that the displacement of the two adjacent 
 rock masses took place, not along the line of greatest dip, but in 
 a diagonal direction, causing a shifting sideways as well as 
 downwards. Nevertheless, where beds or veins are not horizontal, 
 a mere shift along the line of dip is suffi- 
 cient to cause a heave sideways. This will FIG. 86. 
 be understood from Fig. 86. Let AB 
 and CD represent two portions of the lode 
 dislocated by the fault EF. The point B' 
 corresponded originally with B, and the 
 dislocation was caused by the simple 
 sliding of B' along the line of dip of the 
 fault. Here again the miner would speak 
 of the heave as taking place to the left. 
 
 The subject of the heaves of lodes and 
 
 beds has been elucidated by Schmidt,* Zimmermann t and 
 others. 
 
 Zimmermann's rule for finding the lost part of a vein on the 
 other side of a fault is as follows : 
 
 Lay down upon paper the line of strike of the lode and the 
 line of strike of the fault (cross-course), and by construction 
 ascertain the horizontal projection of the line of their intersection ; 
 from the point where the cross-course was struck by the lode, 
 draw a line at right angles to the strike of the former and 
 directed to its opposite wall. Notice on which sile of the line of 
 
 * Theorie der Verschiebung alter er Gauge. Frankfort, 1810. 
 t Die Wiederausricktung vcrworfener Gauge, Lager und Flbtze. Darm- 
 stadt and Leipsic, 1828. 
 
9 2 
 
 ORE AND STONE MINING. 
 
 FIG. 87. 
 
 intersection this perpendicular falls, and, after cutting through 
 the cross-course, seek the heaved part of the lode on that side. 
 Thus let AB (Fig. 87) represent, at some given depth, the line 
 
 of strike of a fault or cross- 
 course dipping east, and CD 
 the line of strike of a lode dip- 
 ping south, and we will sup- 
 pose that in driving from C to 
 D, in a westerly direction, the 
 fault has been met with at D. 
 Knowing the dip of the lode 
 and that of the fault, it is easy 
 to lay down, on any given scale, 
 A'B' and C'D', the lines of 
 strike of the fault and lode 
 respectively at a certain depth, 
 say ten fathoms, below AB. 
 The point D", where A'B' and C'D' meet, is one point of the 
 line of intersection. Join D and D" and prolong on both sides. 
 The line MN represents the horizontal projection of the line of 
 intersection of the two planes. At D erect DE at right angles 
 to AB, and directed towards the opposite wall of the fault. As 
 
 
 DE falls south of MN, the miner, after cutting through the fault 
 would drive in a southerly direction, and eventually strike the 
 lode again at F. It will be at once understood that if the miner 
 were following the lode from G to F, the perpendicular would lie 
 to the north of the line of intersection, and following the rule 
 he would drive in that direction, after cutting through the fault. 
 
 When several faults dislocate lodes one after the other very 
 great complications may arise. 
 
 Fig. 88* is, fortunately for the miner, an unusual instance of a 
 succession of faults. 
 
 * J. W. Pike, " On some remarkable Heaves or Throws in Fenhalls 
 Mine," Quart. Jour. Geol. Soc. t vol. xxii. (1866), p. 537. 
 
( 93 ) 
 
 CHAPTER II. 
 
 PROSPECTING. 
 
 Chance discoveries. Adventitious finds. Uses of geology. Associated 
 minerals. Surface indications : form, colour, gozzans, springs, indica- 
 tive plants, burrows of animals. Sheading. Hushing. Piercing. 
 Lode-lights. Altered \egetation and other indications. Old workings, 
 slag heaps, ruins. Names of places. Divining-rod. Dipping needle. 
 Qualifications of the prospector. 
 
 Chance Discoveries. The number of discoveries of valuable 
 mineral deposits by pure chance is very great. I will mention a 
 few cases, mostly recent, taking the minerals in alphabetical order. 
 
 Amber. Pieces of amber cast up on the shores of the Baltic 
 after storms, no doubt were the first sources of supply of the 
 mineral, and eventually led to a search for the parent beds. 
 
 Cobalt. The cobalt ore recently worked in Flintshire was dis- 
 covered in 1870, by Mr. Gage, who happened to test with the 
 blowpipe some black matter which formed strings in the Carboni- 
 ferous Limestone. 
 
 Copper. The owner of a sheep run on Yorke's Peninsula, 
 South Australia,* picked up some atacamite on the coast in 1859, 
 and became convinced that there were deposits of copper ore 
 inland. In 1860 he came across the workings of a wombat which 
 had thrown out a quantity of this green ore in making its burrow. 
 Pits were put down, and the great Wallaroo lode was thus dis- 
 covered. Other lodes in the district were afterwards hit upon in 
 the same way, or from green ore thrown up by some burrowing 
 insect. 
 
 Diamonds. The fate of South Africa has been wholly changed 
 by the finding of diamonds. Mr. O'Reilly, a trader, describes his 
 discovery in these words : 
 
 "In March 1867, I was on my way to Colesberg, from the 
 junction of the Yaal and Orange Rivers; I outspanned at Mr. 
 Niekerk's farm, where I saw a beautiful lot of Orange River 
 stones on his table, which I examined. I told Niekerk they 
 were very pretty. He showed me another lot, out of which I at 
 once picked the ' first diamond.' I asked him for it, and he told 
 me I could have it, as it belonged to a Bushman boy of Daniel 
 
 * S. Higgs, " Some Remarks on the Mining District of Yorke's Peninsula, 
 South Australia," Trans. It. Geol. /Sue. Cornwall, vol. ix. p. 127. 
 
94 ORE AND STONE-MINING. 
 
 Jacobs." Mr. O'Reilly then sent the stone to Cape Town for 
 examination, when it turned out to be a true diamond, worth 
 
 The value of the diamonds produced annually far exceeds that 
 of the gold of any one of our colonies. 
 
 Gold. The story told of the finding of gold in California, in 
 1848, is that Marshall, who was superintending a sawmill, hap- 
 pened to see something glittering in the mill leat. It turned out 
 to be gold. He found more nuggets, and soon the discovery was 
 noised abroad. 
 
 In Australia the first discoveries of gold were by chance. 
 
 The attention of Dr. Plassard was directed to the existence of 
 gold in Venezuela from seeing some specimens in the possession 
 of a native. 
 
 Iron. Traces of soft haematite, noticed among the roots of an 
 overturned tree, led to the discovery, in 1891, of the important 
 Biwabikf iron mines of the Mesabi range, Minnesota. 
 
 Nickel. The Sudbury nickel deposits were discovered in 
 making a cutting for the Canadian and Pacific Railway, and even 
 then it was the copper which first attracted notice. 
 
 Phosphate of Lime. In May 1886, a geologist, M. Merle, took 
 it into his head to analyse the sand of an apparently abandoned 
 pit, which had been worked for centuries in order to give bricks 
 a violet tint much esteemed in the neighbourhood. He found it 
 contained 77*85 per cent, of phosphate of lime. This was the 
 origin of the workings in the Upper Chalk at Beauval, in the 
 department of the Somme.J 
 
 The discovery of the phosphate beds of Florida was made in the 
 autumn of 1889 by an orange-grower, who out of curiosity sent 
 to a chemist a sample of the white subsoil of his grove; this 
 turned out to contain 80 per cent, of phosphate. 
 
 Quicksilver. The Redington Quicksilver Mine,|| in California, 
 was discovered in making a cutting for a road. 
 
 Silver. A man made a fire to cook his food and protect himself 
 from the cold, near the site of Catorce,^] in Mexico, and in the 
 morning found silver shining in the ashes. This was in 1775, 
 
 * T. Eeunert, " Diamond Mining at the Cape," Official Handbook to the 
 Colonial Exhibition. History, Productions, and Resources of the Cape of 
 Good Hope. Cape Town, 1886, p. 178. 
 
 t Winchell, Twentieth Annual Report of the Geol. and Nat. Hist. Survey of 
 Minnesota, p. 157. Minneapolis, 1893. 
 
 + Statisque de V Industrie Minerals en France pour Vannee 1886. Paris, 
 1888, p. 252. 
 
 Ledoux, " The Phosphate Beds of Florida," Eng. Mln. Jour., vol. xlix. 
 (1890), p. 176. 
 
 || Becker, " Geology of the Quicksilver Deposits of the Pacific Slope," 
 Monographs of the U.S. Geol. Survey, vol. xiii. p. 10. Washington, 1888. 
 
 ^[ Chism, "The Catorce Mining District," Eng. Min. Jour., vol. xlviii, 
 (1889), P- 340. 
 
PROSPECTING. 95 
 
 and three years later another man pulled up a bush to throw 
 upon his fire, and found native silver in the roots. Mining soon 
 began, and between 1779 and 1812 the district yielded ore worth 
 from thirty to forty million pounds sterling. Tradition relates 
 that the famous silver mines of Potosi, in Bolivia, were dis- 
 covered in a similar manner in 1538, by the accidental displace- 
 ment of a bush which had small lumps of native silver among the 
 roots. 
 
 The existence of silver in the Province of Famatina, in the 
 Argentine Republic,* was made known by a pure accident. Leita 
 and Echavarria were making a journey, in 1811, across the Andes, 
 and during a terrible storm, took refuge in a cave, and there 
 passed the night. In the morning they found that the stones 
 they had put round the fire at night were white, and on further 
 examination silver was plainly to be seen in them. 
 
 Adventitious Finds. Search for one mineral often leads to 
 the discovery of another. The working of veins for tin ore has 
 revealed the presence of the decomposed granite which furnishes 
 china clay. 
 
 The finders of the Comstockf lode worked it at first for gold, 
 being quite ignorant of the presence of rich silver ore. 
 
 In the winter of 1858-59, some prospectors washed a panful of 
 earth from a broad-topped mound which one of them had 
 noticed previously. This gave gold to the value of fifteen cents, 
 a high average return. They then noticed a gopher hole in the 
 mound, and took up the earth which had been thrown up. This 
 they washed, with satisfactory results, and at once staked out 
 claims. Another part of the lode was discovered by some other 
 prospectors, who had dug a hole in order to make a little reservoir 
 for water. They chanced to wash some of the earth, and to their 
 surprise found it rich in gold. The upper part (back) of the lode 
 was then worked for this metal. They threw away bits of a black 
 rock which they found mixed with the earth and yellow sand, 
 and when, at a depth of 3 or 4 feet, they came upon a vein of the 
 black mineral, they had not the least idea that it was valuable. 
 Pieces, however, were carried away by curious visitors, and one 
 was given to Mr. Melville Attwood for assay. He discovered 
 that it was worth $3,000 per ton for silver and $876 for gold. 
 The black mineral was sulphide of silver, and the yellow sand 
 proved to be the chloride. The working of the Comstock 
 lode for silver dates from this discovery, which was in June 1859. 
 There are reasons for supposing that the original discoverers 
 of the Comstock lode were two brothers na med Grosh who had 
 found a rich vein of silver in 1856. But one brother died from 
 
 * Hoskold, La Bepublique Argentine, p. 19. 
 
 f Lord, " Comstock Mining and Miners," Monographs of the U.S. Gtol. 
 Survey, vol. iv. pp. 34-55. 
 t Op. cit. pp. 27-31. 
 
96 OHE AND STONE-MINING. 
 
 the effects of a slight accident, and the other soon after succumbed 
 under the hardships he had undergone in crossing the snows of 
 the Sierras in December 1857. The knowledge of this vein was 
 then lost for a time. 
 
 In 1885* some natives or Spaniards took to M. Bastide speci- 
 mens of what they thought was calamine from the top of Djebel 
 Touma'i-Kebir, Department of Oran, Algeria. It turned out to 
 be phosphate of lime. 
 
 When boring for rock salt in 1839 near Stassfurt,f the 
 Prussian Government found brine with chloride of magnesium 
 and chloride of potassium. Later, in 1852, they sank two shafts 
 through the beds containing these minerals, without in any way 
 recognising their value, in order to work the rock-salt underneath. 
 However, it was not long before this mistake was corrected, and 
 the potassium salts soon became the main object of the mining. 
 
 The sub-wealden bore-hole near Battle, which was put down 
 for general information concerning the underlying strata, met 
 unexpectedly with a bed of gypsum, which is now regularly 
 mined. 
 
 The bed of salt in the Cleveland district was discovered in 1863 
 by a boring made for the purpose of getting water. The total area 
 now proved is 20 square miles ; and if the approximate average 
 thickness of the bed is taken at only 90 feet, it may be estimated 
 to contain 115,200,000 tons of salt per square mile.J 
 
 A bore-hole was put down in Louisiana near Lake Charles on 
 the New Orleans-Texas Railway in search of petroleum, and a 
 rich bed of sulphur-bearing rock, 100 feet (30 m.) thick, was 
 pierced unexpectedly. Owing to the watery nature of some of 
 the strata by which it is overlain, it has not yet been worked. 
 
 According to a statement issued by the Broken Hill Proprietary 
 Company, Limited, || the original claims of this productive silver 
 mine were pegged off under the impression that the outcrop was 
 that of a tin lode. 
 
 The Sulphur Bank^J in California was originally worked for 
 sulphur, and the fact of there being quicksilver was long 
 unsuspected. 
 
 Instances of valuable minerals passing unrecognised are 
 common. 
 
 It is related that the original proprietor of the site of Mount 
 
 * Statistique de V Industrie miner ale. en France pour Vannee 1886. Paris, 
 1888, p. 285. 
 
 t Fuhrer zum vierten aVgemeinen Deu'schen Bergmannstag. i88g. Halle 
 a. d. Saale, 1889, p. xxxiii. 
 
 % Marley, " On the Cleveland and South Durham Salt Industry," Trans. 
 F&L Inst. M.E., vol. i. (1889-90), p. 342. 
 
 Rivista del Servizio Miner ario, 1 888, p. cl xxxiii. 
 
 || Report and Statement of Accounts for Half-year ending November 30, 
 1886. Melbourne, Victoria, 1886, p. 57. 
 
 ^[ Becker, op. cit. p. 10. 
 
PROSPECTING. 97 
 
 Morgan gold* mine used to sell some of the auriferous stone, 
 which resembles pumice, as hearthstone for cleaning doorsteps. 
 
 Geology as a Guide to Minerals. A knowledge of 
 geology will often serve to guide the miner. Coal has been 
 discovered in the south-east of England by very careful reasoning, 
 based upon the geological structure of South Wales and Somer- 
 setshire on the west and that of Northern France and Belgium on 
 the east. 
 
 M. Meugy,*f* Inspector- General of Mines, hearing of the dis- 
 covery of phosphate of lime in the Lower Greensand of England, 
 concluded that similar deposits might occur in the Cretaceous 
 rocks cf France. Search was made, and valuable deposits were 
 found in 1852. 
 
 Geology also affords the miner aid by enabling him to identify 
 certain horizons in stratified rocks by their fossils. The valuable 
 bed itself may not always be fossiliferous, but definite horizons 
 above or below it may be recognisable, and so guide the miner in 
 his explorations. 
 
 Associated Minerals. The existence of valuable minerals may 
 be suspected from meeting with some of their common associates, 
 and, even for the sake of its importance to the prospector, the 
 subject of the paragenesis of minerals deserves careful study. 
 
 The facts are specially marked in the case of tin ore. Cassit- 
 erite is usually associated with minerals containing boron and 
 fluorine, such as tourmaline, topaz, fluor-spar and lithia mica, 
 and also with wolfram, chlorite, and arsenical pyrites ; masses of 
 magnetic iron ore are frequently accompanied by rocks containing 
 garnets, hornblende, and epidote. 
 
 Zinc blende is a common hanger-on of galena, which likewise 
 often has barytes in its train. Galena invariably contains silver, 
 and frequently enough to enhance its value. 
 
 The associates of gold in quartz veins are various metallic 
 sulphides, such as iron pyrites, magnetic pyrites, copper pyrites, 
 mispickel, galena, zinc blende, stibnite, tetradymite, and bis- 
 muthine. 
 
 Salt is accompanied by gypsum and anhydrite, and frequently 
 has its habitat in red rocks. Mottura explains this by pointing 
 out that when sea water is evaporated, the first precipitate is oxide 
 of iron, that gypsum crystallises out next, and later the sodic 
 chloride. 
 
 SURFACE INDICATIONS. The indications which guide 
 the prospector are precisely those upon which the geological sur- 
 veyor depends in making his maps, viz., form of the ground, colour, 
 nature of the decomposed outcrop, ordinary springs, mineral 
 springs, indicative plants, altered vegetation, burrows of animals, 
 old workings, slag heaps, ruins, names of places and old records. 
 
 * W. H. Dick, A Mountain of Gold. Brisbane, 1889, p. n. 
 j- Stat* Min. France, 1886. Paris, 1888, p. 280. 
 
 
 
98 ORE AND STONE-MINING. 
 
 Form of the Ground. If the valuable mineral is harder or 
 softer than the surrounding rocks, it will affect the manner in 
 which the surface is sculptured by atmospheric agencies. Hard 
 rocks will project in some way, soft ones will be cut into hollows, 
 especially if they are impermeable. The outcrop of a hard bed will 
 be denoted by a .steep face or escarpment, and unyielding mineral 
 veins project above the surface in the form of huge crags (Fig. 89). 
 
 In parts of our country, these out- 
 FIG. 89. crops have been worked away and 
 
 are no longer apparent; but lode- 
 quartz blanched by weathering may 
 often be seen standing up several 
 feet above the surface on the Welsh 
 hills, and the run of some lodes can 
 be traced for a long distance by a 
 succession of such outcrops. 
 
 In the United States and in Australia this phenomenon is 
 common. 
 
 At the Great Western Quicksilver Mine* in California, the 
 outcrop of the vein appears as a dike over 100 feet wide, and 
 having precipitous sides in places 75 feet high. 
 
 Some of the silver veins of Butte, Montana, crop out, according 
 to vom Rath,t as great wall-like ridges of brown and black rock, 
 which is quartz containing the oxides of iron and manganese ; the 
 Rainbow lode stood up 20 feet above the surface. 
 
 The Broken Hill lode at Silverton, New South Wales, was 
 traceable for fourteen miles by the outcrop of huge black crags 
 consisting of ferruginous quartz, brown ironstone, pyrolusite and 
 other minerals, which in places rose to a height of 50 feet above 
 the ground, and were 10 to 120 feet wide. 
 
 Speaking of the outcrops of gold veins of the Hodgkinson gold- 
 field of Queensland, Mr. R. L. Jack,J the government geologist, 
 says, " they can be followed from hill top to hill top, forming at 
 times insurmountable walls a hundred feet high ; as, for example, 
 in the peaks west of Mount Tenison Woods. In other places 
 denudation has left their remains on hill sides or hill tops in the 
 form of huge cubes of quartzite, from which the surrounding soft 
 rocks have crumbled away. These cubes stand up weird and 
 solitary, like the * perched blocks ' of Alpine and Arctic lands." 
 
 The tin lodes of San Jacinto in California are found in a 
 country destitute of all vegetation except grass, and their black 
 outcrops are said to be unusually distinct. 
 
 * Luther Wagoner, " The Geology of the Quicksilver Mines of California," 
 Eng. Min. Jour., vol. xxxiv. (1882), p. 334. 
 
 f Neues Jahrb. f. Miner., GeoL, u. Palaontoloyie, 1885, p. 162. 
 
 Handbook of Queensland Geology. London, 1886, p. 27. 
 
 Benedict, "The San Jacinto Tin Mines," Eng. Min. Jour., vol. 1. (1890), 
 p. 452, 
 
PROSPECTING. 99 
 
 The Great Quartz Yein of California has "a very conspicuous 
 outcrop, forming the crest of the hills, so that it can be readily 
 seen from a distance of several miles."* 
 
 The " main reef " of auriferous conglomerate at Johannesburg, 
 in the Transvaal, could be traced in places by the pebbles on 
 the surface. 
 
 Soft minerals like clay offer less resistance to rain, flood, and 
 frost, are more deeply cut into, and give rise to hollows. Thus 
 the bed of clay known as the Gault, occupies a depression between 
 the hard and pervious beds of the Chalk and the Lower Greensand. 
 
 The presence of the masses of decomposed granite which fur- 
 nish china clay f is almost always indicated by a slight depression 
 of the surface. 
 
 The ore bodies in the Sierra Mojada, Mexico, are softer than 
 the enclosing rocks, which often stand out when the ore has been 
 worn away by weathering. J 
 
 Colour. Colour is an important factor in the discovery of 
 mineral deposits. Sometimes the ore itself has a distinct hue. 
 When Garnier was exploring New Caledonia in 1863, he was 
 struck by the special green colour of the rocks, and he found 
 that it was due to coatings, veins, and lumps of a hydrous silicate 
 of nickel and magnesium, which is now largely worked. 
 
 Copper minerals will produce green, blue, and red stains, 
 which catch the attention very quickly. Iron gives a red or 
 brown colour, manganese a black ; lead may furnish a green, a 
 yellow, or a white coating, cobalt a pink one, whilst cinnabar is 
 the natural vermilion. Coloured minerals are often used as pig- 
 ments by savages, and in this way may be brought to the know- 
 ledge of the explorer. 
 
 G-ozzan. A mineral deposit near the surface is frequently so 
 altered by atmospheric agencies that it bears little resemblance to 
 the undecomposed bed or vein which will eventually be met with at 
 a greater depth. A bed of hard shale will crop out at the surface 
 as a soft clay ; but the most common cases of change are furnished 
 by the conversion of sulphides into oxides or oxidised compounds, 
 and the removal of some of the mineral in the form of a soluble 
 sulphate. Thus iron pyrites, which is such a frequent constituent 
 of mineral veins, is converted into hydrated oxide of iron, and a 
 vein, originally consisting of iron pyrites and quartz, becomes a 
 honeycombed brown and yellow rock, the removal of the iron 
 pyrites in the form of a soluble sulphate leaving cavities which 
 are only partly filled up by oxide. The ferruginous solutions 
 which flow away stain and discolour the adjacent rock. 
 
 * Whitney, TJie Auriferous Gravels of the Sierra Nevada of California. 
 Cambridge, U.S., 1880, p. 46. 
 
 t J. H. Collins, " The Hensbarrow Granite District." Truro, 1878, p. 7. 
 
 Chism, " Ore Deposits of Sierra Mojada/' Trans. Am. Inst. M.E.. vol. 
 xv. (1886-87), P- 549- 
 
ioo ORE AND STONE-MINING. 
 
 The ferruginous outcrop of mineral veins has been noticed in 
 all mining countries. In Cornwall it is called gozzan, and this 
 term has been carried by the ubiquitous Cornish miner to other 
 English-speaking countries, though in Australia we hear of iron- 
 stone blows. 
 
 In Germany the iron hat gives the proverb 
 
 Es ist kein Bergwerk trie so gut, 
 Es hat denn einen eisern Hut; 
 
 translated by the late Sir Warington Smyth as follows 
 
 " A lode will ne'er cut rich and fat, 
 Unless it have an "iron hat." 
 
 In France the chapeau enfer is the equivalent of the German 
 expression, whilst the Italian miner, ascribing the cindery, burnt- 
 up appearance to the action of fire, calls such outcrops bruccioni* 
 The Spanish term colorados has reference to the red tint due to 
 iron oxides. In some parts of South America, such as the 
 Argentine .Republic and Bolivia, the word pacos is used for the 
 oxidised ores. 
 
 The nature of a gozzan varies naturally very greatly, not only 
 in different districts, but also in different parts of the same lode. 
 If the vein originally consisted very largely of iron pyrites, the 
 gozzan will be mainly ochre and brown iron ore, often in botry- 
 oidal and stalactitic forms. If quartz was present also, a cellular, 
 cindery, cavernous, ferruginous rock is the result of the atmos- 
 pheric weathering. 
 
 Other metallic minerals will leave their traces. Galena be- 
 comes changed into anglesite, cerussite, pyromorphite, and mime- 
 tite. The sulphides of copper yield native copper, melaconite, 
 cuprite, malachite, chessylite, together with phosphates, arseniates, 
 and silicate of the metal, and sometimes the oxychloride or oxy- 
 sulphide. Carbonate of manganese gives rise to black oxides, whilst 
 argentiferous minerals furnish native silver, kerargyrite and 
 embolite. 
 
 Gold is unlocked from enveloping sulphides, and specimens of 
 quartz may be seen from nearly every gold-field in which cubical 
 cavities, left by the removal of iron pyrites, are partly "Vied up 
 with ochre and delicate skeletons of the precious metai Gold 
 may exist in combination with other elements and be HL- ted 
 by the weathering process. 
 
 The depth to which the oxidising and leaching action proceec. 
 is often considerable. In the Comstock lode f " the quartz is 
 reddened and the iron minerals more or less oxidised to a depth 
 of 500 feet, but it is probable that the lower ioo feet are chiefly 
 
 * Zoppetti, Arte Miner aria. Milan, 1882, p. 85. 
 
 t Hague, Mining Industry of the Fortieth Parallel. Washington, 1870, 
 P- 75- 
 
PROSPECTING. 
 
 101 
 
 coloured by the percolation of the surface waters." Sometimes 
 there is a sharp line of demarcation, sometimes a gradual passage, 
 between the gozzan and the sulphides. 
 
 In the sections of a mineral vein, Figs. 90 and 91, A, is the 
 gozzan, showing itself occasionally by rough crags at the surface ; 
 0, represents the undecomposed sulphides, and B is an interme- 
 diate zone where the process of alteration is incomplete. At 
 Huanchaca silver mine, Bolivia, the oxidised ores near the sur- 
 face are called pacos, the transition oxysulphides mulatos, whilst 
 the unchanged sulphides are known as mctales frios. In the 
 longitudinal section, Fig. 91, the alteration is shown as ceasing 
 
 FIG. 90. FIG. 91. 
 
 soon after the level of the bottom of the valley is reached, that 
 is to say when the water no longer has an easy exit ; but cir- 
 cumstances may bring about a system of circulation causing the 
 rainwater to penetrate below this level, and then the gozzan will 
 naturally extend to a greater depth. 
 
 Gozzan is important to the miner not only because it is an 
 indication of a lode, but also because the ore is sometimes more 
 valuable from the decomposition of the sulphides. This is 
 specially the case with gold and silver. Gold, as already explained, 
 is set free from a tight covering of pyrites, or possibly from a state 
 of combination with some other element, and can now be easily 
 caught by quicksilver. The miner speaks of the ore as "free- 
 milling " on this account. Silver, when brought into the native 
 state, or converted into chloride, is likewise readily extracted by 
 amalgamation. 
 
 In the case of argentiferous lead veins, chloride of silver mixed 
 with carbonate of lead and oxide of iron is more acceptable to 
 the smelter than a complex mass of metallic sulphides. The 
 removal of zinc blende by atmospheric agencies, no doubt through 
 its conversion into a soluble sulphate, is of much importance; 
 for the ore is thus freed from an ingredient which gives trouble 
 in the lead furnaces, and which cannot be satisfactorily separated 
 mechanically when very intimately mixed with galena, iron 
 pyrites and other sulphides. Furthermore the removal of some 
 
102 ORE AND STONE-MINING. 
 
 of the heavy worthless ingredients, whilst the silver remains 
 fixed as insoluble chloride, raises the tenour of the ore in 
 the precious metal. Lastly, the upper parts of the vein are 
 more cheaply worked from their softness, and the small cost 
 of pumping and winding. Under these circumstances the fact 
 of a mine sometimes becoming less profitable, or wholly un 
 profitable, when the zone of sulphides is reached will easily be 
 understood. 
 
 These points must not fail to be considered by the miner ; he 
 must recollect that the zone of the oxidised ores will be succeeded 
 by sulphides, more costly to work, and sometimes requiring 
 totally different treatment. 
 
 Gozzans should be carefully assayed, especially for silver. 
 Instances could be given of gozzans having been stamped and 
 worked for gold, to the utter neglect of the silver which was by 
 far the more valuable ingredient. 
 
 In Cornwall gozzans of copper lodes have been worked for tin 
 ore, which was originally enclosed in or mixed with copper and 
 iron pyrites. Owing to its insolubility it resisted the weathering 
 which carried away the copper and some of the iron in solution. 
 
 The Anaconda mine* at Butte, Montana, now famous for its 
 enormous output of copper, was originally bought as a silver 
 mine. For a depth of 400 feet the ores contained no notable 
 quantity of copper ; this metal had been carried off in solution, 
 whilst the silver, converted into an insoluble chloride, was 
 rendered proof against any further action of rainwater. 
 
 Deposits of cupreous iron pyrites may have the copper and 
 sulphur so completely removed that the remaining oxide of iron 
 is worked as an ore of this metal. t 
 
 The iron ores of Bilbao are the decomposed portions of deposits 
 of the carbonate. The weathering has had two useful effects, 
 it has raised the percentage of iron, and it has lowered the 
 amount of sulphur by decomposing the iron pyrites, which occurs 
 in small quantities in the unaltered ore. 
 
 The seams containing native sulphur in Sicily often show no 
 trace of that element at the surface, as the sulphur-bearing 
 limestone weathers into a soft, white, grey, or yellowish white ? 
 granular or pulverulent variety of gypsum, called briscale* 
 by the miners, and considered by them to afford important 
 indications concerning the bed itself. In this case the sulphur 
 has gradually become oxidised and has combined with some of 
 
 * Douglas, " The Copper Resources of the United States," Trans. Amer. 
 Inst. M.E., vol. xix. (1890-91), p. 679. 
 
 t Moxham, "The ' Great Gossan Lead ' of Virginia," Trans. Amer. Inst. 
 31. E., vol. xxi. (1892), p. 134. 
 
 + Lorenzo Parodi, SuW estrazione dello &olfo in Sicilia. Florence, 1873, 
 pp. 7, 24 ; and L. Baldacci, Descrizione geoloyica ddV Isola di Sicilia. 
 Rome. 1886 p. 1 06. 
 
PROSPECTING. 103 
 
 the lime to form a sulphate; and it is only natural to suppose 
 that the thicker and the richer the original bed was, the greater 
 will be the amount of briscale produced, and the more apparent 
 its signs on the surface. 
 
 Each mineral therefore has to be considered separately, and I 
 may mention a few other special cases. 
 
 Veins of asbestos have been discovered by noticing a white 
 powdery substance in cracks in the rocks, which led to fibrous 
 asbestos when worked. 
 
 Steam-puffs are indications of the small superficial deposits of 
 sulphur in volcanic districts; and here sight is aided by the sense 
 of smell, for I recollect remarking the odour of sulphuretted 
 hydrogen long before I rode up to some sulphur banks in 
 Iceland. In Tuscany the natural steam-puffs which yield boracic 
 acid are plainly visible, and bore-holes * are also put down to 
 produce them artificially where the rocks are hot at the surface, 
 and so give hopes of tapping vapour at a shallow depth. 
 
 Some of the successful bore-holes for carbonic acid gas in the 
 Eifel, Germany, were planned on account of natural emanations 
 of the gas in the immediate vicinity. 
 
 Attention has been directed to petroleum by a layer or an 
 iridescent film of the oil upon pools of water, and the odour is 
 sometimes perceptible for a long distance. Off Baku, on the 
 Caspian, even the sea is sometimes covered with an oily film of 
 petroleum. 
 
 Brine springs point to salt, chalybeate springs to iron, but not 
 necessarily to deposits of any commercial value ; the same may 
 be said of water impregnated with sulphuretted hydrogen as an 
 indication of native sulphur. Springs of ordinary water may be 
 expected to appear where a pervious bed rests upon an imper- 
 vious one, so that the outcrop of a bed of clay under sandstone 
 is often denoted by a succession of springs, in addition to the 
 change in the form of the ground. 
 
 Even when the valuable deposit presents no striking outcrop, 
 it may be followed by observing some more marked attendant. 
 Thus the " red bar "f of the Johannesburg district, is a bed of 
 dark red slate which is seen protruding above the surface, a little 
 to the north of the gold-bearing conglomerate, for a distance of 
 20 miles along the strike. 
 
 In California + a dark opaline or chalcedonic rock, known to 
 the miners as " quicksilver rock," is associated with the deposits 
 of cinnabar, and owing to its comparative hardness stands out 
 sometimes as a projecting outcrop. 
 
 Indicative Plants. As plants derive part of their nouri^h- 
 
 * Jervis, 1 lesori sotterranei deW Italia, vol. ii. p. 428. 
 t Quart. Jour. Geol. Soc., vol. xlvi. (1890), Proceedings, p. 4. 
 Becker, ' Geology of the Quicksilver Deposits of the Pacific Slope, 
 Monographs of ike U.S. Geol. Survey, vol. xiii. p. 360. Washington, iSSS. 
 
io 4 OHE AND STONE-MINING. 
 
 ment from their roots, and as different plants require different 
 foods, it is only natural to suppose that a change of soil causes a 
 change in the vegetation. 
 
 Beds of porous limestone let the rain soak down at once, the soil 
 is shallow, and the foothold for trees is not so good as in the 
 case of clays. Thus the chalk hills are bare, and the Weald clay 
 is the home of the oak from a mechanical reason, in addition to 
 the chemical one of nourishment. 
 
 Clays will retain water and naturally be the habitat of rushes 
 and other moisture-loving plants. 
 
 The effect of salt in the rocks is especially marked, and 
 Gatzschmann* gives a long list of plants which either flourish best 
 when getting salt, or cannot exist without it. 
 
 The flora of Monte Catini,f in the province of Lucca, well 
 known for its brine baths, resembles that of the coast, although 
 24 miles away from the sea, and separated from it by the Pisan 
 Hills. 
 
 My friend, Mr. S. Herbert Cox, tells me that the run of the 
 deposit of alunite which he is working in New South Wales, is 
 marked by a lighter green in the colour of the leaves of the 
 eucalyptus trees which cover the district. He has also noticed 
 in New Zealand that the Karacca trees growing upon limestone 
 have darker leaves than those growing upon slate. A band of 
 limestone can be traced in this way. 
 
 The subject of indicative plants is dealt with in an interesting 
 paper by Raymond,* who gives some additional details concerning 
 the calainine pansyof Rhenish Prussia, mentioned by Gatzschmann. 
 This pansy, called by botanists Viola calaminaria, is peculiar to 
 the calamine-bearing hills near Aix-la-Chapelle, and in West- 
 phalia. The blossoms are almost always yellow ; but on 
 the borders of the zinc regions some are light violet, or bluish, 
 or mixed yellow and blue, and are supposed to be hybrids 
 between V. calaminaria and the ordinary wild pansy, V. tricolor. 
 Analysis has revealed the presence of zinc in the plant 
 and in the sap. This plant is said to have been recognised at 
 Horn Silver Mine in Utah, the ore of which contains zinc 
 blende. 
 
 The lead plant, Amorpka canescens, Nutt., is a low shrub, i ft. 
 to 3 ft. high, whitened with hoary down. The plant is most 
 abundant in Michigan, Wisconsin, and Illinois, and miners 
 believe that it flourishes best where lead ore exists in the soil. 
 
 Dr. F. Stapff found that prospectors for phosphorite, in 
 Estremadura were guided by a creeping plant with bell-shaped 
 flowers, Convolvulus althceoides ; in Montana the Erigonum 
 
 * Die Aufsuchung und Untersuchuny von Logerstdtten nutzbarer Miner alien. 
 Leipsic, 1866, p. 321. 
 
 t Jervis, Guida alle acque minerali d 1 Italia. Turin, 1868, p. 12. 
 J Trans. Am. Inst. M.E., vol. xv. (1886-87), p. 647. 
 
PROSPECTING. 105 
 
 ovali/olium, Nutt., is looked upon as an indication of silver ore in 
 the vicinity. 
 
 Animals as Indicators. -Animals also may occasionally 
 render services to the prospector. I have already mentioned the 
 case of the wombat, by whose burrows copper was discovered in 
 South Australia. Prospectors seeking for tin lodes in Victoria* 
 have also been guided to success by the ore thrown out from 
 decomposed dykes by this animal. Ledouxf says that a useful 
 indication of phosphate of lime in Florida was furnished by ant- 
 hills and gopher holes, which showed small whitish grains of the 
 mineral in the earth. 
 
 GatzschmannJ mentions cases of the discovery of valuable ores 
 by the scratchings of the beaver, the bear, and the marmot, as 
 well as by the wallowing of pigs ; he also brings forward in- 
 stances in which the first indications of mineral wealth were 
 afforded bv stones kicked up by a horse, or tossed out by a 
 bull, or lying in the nest of a vulture, or found in the crop of a 
 grouse. 
 
 At the Caratal diggings in Venezuela, a bird called the minero 
 was thought to mark the site of gold-bearing gravel. I often 
 heard its notes when passing pits where gold was being obtained, 
 and it is possible that it preferred certain trees which grew upon 
 the old alluvia. In fact, as so many animals obtain their food 
 from special plants, it is evident that the fauna dependent upon the 
 flora must be affected indirectly by the minerals of the soil. The 
 special case of there being more genera and species of snails in a 
 limestone country is a case in point. Lastly, the tracks of animals 
 may lead to salt springs which they frequent. 
 
 Sheading. The prospector seeks for natural sections of the 
 rocks such as occur in cliffs, or in river valleys and their tributary 
 gullies and gorges. He examines the materials constituting the 
 river beds, especially when the water is low in the dry season, 
 often digging up and washing portions in a pan or in a batea, in 
 order to ascertain whether they contain traces of the heavy ores 
 or metals. 
 
 If, while prospecting in a valley, he discovers stones that have 
 the appearance of having once belonged to veins or other valuable 
 deposits, he endeavours to trace them to their source, and is, 
 perhaps, rewarded by finding similar fragments, but less water- 
 worn, as he goes up the stream. Further on he may come upon 
 large blocks of veinstuff lying about, and finally find the veins 
 laid bare in a gorge, or at the bottom of a brook, or possibly pro- 
 jecting above the soil in the form of huge crags of quartz in the 
 manner already described. 
 
 * Victoria, Reports and Statistics of the Mining Department for the Quarter 
 ended March 31, 1890, p. 15. Melbourne, 1890. 
 
 t A. R. Ledoux, "The Phosphate Beds of Florida," Eng. Min. Jour., 
 vol. xlix. Feb. 1890, p. 176. J O}>. r,it. p. 311 
 
io6 ORE AND STONE-MINING. 
 
 Loose pieces of veinstuff found lying about on the surface are 
 known in Cornwall as shoad- stones ; and sheading ,is the term 
 given to the process of tracking them to the parent lode. 
 
 If the prospector has ascertained the existence of a lode by 
 shoad-stones, and has some idea of the position of the outcrop 
 which lies concealed under the soil, he proceeds to dig trenches 
 across the presumed line of strike, until he hits upon the back 
 of the lode. When the covering of soil is too deep for trenching, 
 a little shaft is sunk, and a tunnel is driven out at right angles 
 to the supposed course of the vein. 
 
 Loaming in Australia corresponds to sheading. The prospector 
 washes earth from the base and slope of a hill till the specks 
 of gold are pretty frequent, and then endeavours to trace the gold 
 uphill to the reef that furnished it. When he can no longer get 
 gold by washing he concludes he has gone past the outcrop of the 
 reef, and he proceeds to search for it by trenching. Reefs have 
 been discovered in this way which showed no surface indication 
 whatever.* 
 
 Hushing. f Hushing consists in causing a strenm of water 
 to rush down a hillside, and cut a ditch through the soil, which 
 will lay bare the outcrops of veins, if any exist. A reservoir is 
 made at some suitable spot on the high ground, and a shallow 
 gutter is dug down the slope along the line which it is pro- 
 posed the stream should take. The water is allowed to run down 
 gently at first, and then as a torrent, which scours out a trench 
 to the solid rock. An examination of the trench and of the stones 
 washed out of it may result in the discovery of a vein. 
 
 Piercing. In some special cases when the mineral lies very 
 near the surface, and is either harder or softer than the surround- 
 ing rock, the searcher makes use of a sharp pointed steel rod, 
 which he thrusts into the ground. The well-known French } 
 burr-stones, lying in soft sand and clay at a depth of 10 to 18 
 feet, are found in this way ; whilst in the Isle of Man superficial 
 pockets of umber in the Carboniferous Limestone are detected by 
 the ease with which the rod runs down. 
 
 Kauri gum, a semi-fossil resin of New Zealand, which occurs in 
 lumps of about the size of a hen's egg a few inches below the sur- 
 face in the high ground, and a few feet in the swamps, is sought 
 for by a similar tool. 
 
 Mr. Lawn informs me that in the Furness district a pointed 
 iron rod is occasionally used in searching for shallow deposits 
 of haematite, lying within 6 or 8 feet of the surface. The miner 
 examines the point of the rod after thrusting it through the thin 
 
 * "The Gold-fields of Victoria," Reports of the Mininy Registrars for the 
 Quarter ended March 31. 1888. Melbourne, 1888, p. 68. 
 
 t Williams, Natural History of the Mineral Kingdom. Edinburgh, 1789, 
 Vol. i. f>. 370. 
 
 Cullon, Lecture* on Mining. London, iSSi, vol. ii. p. 41. 
 
PROSPECTING. 107 
 
 covering of soil, and if he finds it to be red, he concludes that 
 there is iron ore underneath. If the indications are sufficient, 
 he sinks a little pit and begins to work the ore. 
 
 The valuable bed of phosphatic nodules in South Carolina * is 
 much harder than the overlying sand and clay ; the prospector 
 carrying a steel rod works it down, until he meets with the resist- 
 ing stratum. He notes the depth, which is under 15 feet, as 
 no phosphate is at present worked deeper than that, and after 
 walking on 100 feet further forces the rod down again. By 
 thrusting down the rod at regular intervals in this way, and 
 noting the results, he obtains a general idea of the lie of the phos- 
 phate bed, and proceeds to make a more minute examination by 
 sinking exploratory pits, 10 feet by 5 feet, at intervals of 500 
 feet. The phosphate rock laid bare is taken out, carefully 
 sampled and analysed, and in this way a very fair estimate can be 
 marie of the yield of a given area. 
 
 The process of testing a bed of mineral by pits is sometimes 
 carried out on a very extensive scale. According to Winchell 
 $60,000 have been spent in mere explorations at the Biwabik 
 Iron Mine,f in the Mesabi Range, Minnesota ; but in this case the 
 pits were practically small shafts, many of which exceeded 100 
 feet in depth. 
 
 Lode-lights. Appearances of flame above mineral veins are 
 said to have been seen, and at all events are sufficiently well estab- 
 lished to have received a special name, " lode-lights," in Cornwall. 
 It is possible that a will-of-the-wisp (phosphoretted hydrogen) may 
 have been produced occasionally by the action of organic matter 
 and water upon phosphates, which are so common in the upper 
 parts of mineral veins. 
 
 Marsh-gas is known in the workings of some lead lodes, and 
 may have occasionally issued in sufficient quantity to produce 
 flame when ignited accidentally. 
 
 Altered Vegetation and other indications. One hears of 
 differences in the appearance of the vegetation along the line of 
 mineral deposits, of places where the snow will not lie in the 
 winter, and of vapours hanging over the ground. Though some 
 writers refuse to put any value on these indications, they should 
 not be entirely overlooked, because the outcrop of a lode, of 
 different nature and texture to the surrounding rocks, may readily 
 cause the phenomena just mentioned. One need only look at the 
 rubbish-heaps of some mines, especially those yielding pyrites, 
 which remain year after year bare and barren, to understand the 
 blighting and withering action of the products of decomposition of 
 borne minerals upon vegetation, It is only natural to suppose that 
 
 * Wvatt, The Phosphates of America. New York, 1891^.49. 
 
 t "The Biwabik Mine," Trans. Amer. Inst. M.E., vol. xxi., 1892-3, 
 p. 951 ; and Geol. and Nat. Hist. Survey of Minnesota. Ttoentidk Ann. 
 lley.for the year 1891. Minneapolis, 1893, p. 156. 
 
io8 ORE AND STONE-MINING. 
 
 grass would grow less luxuriantly upon a wide pyritous vein than 
 upon adjacent slate, and that a decided streak of altered colour 
 and growth would be visible upon the turf. 
 
 A very simple experiment will convince the student more 
 readily than the mere statement. Spread a thin layer of earth 
 upon a tray, and imitate the outcrop of a lode by scraping away 
 some of the earth and re-placing it by powdered iron pyrites or 
 marcasite. Now scatter mustard seed over the surface, and 
 water frequently. In the course of a few days there will be a 
 crop of mustard on the earth, but the track of the pyrites will be 
 marked by a bare streak on which the seeds have been killed by 
 sulphate of iron formed by its decomposition. 
 
 The rapid disappearance of snow on the outcrop of a lode has 
 been noticed at Ducktown Mine, Tennessee,* among other places. 
 The oxidation going on in a pyritous lode near the surface must 
 produce a certain amount of heat, which would make the outcrop of 
 a lode warmer than the adjacent rock ; but one need not have 
 recourse to this hypothesis in order to account for phenomena of 
 this kind. Mineral veins are often channels along which under- 
 ground waters circulate ; this water may come near to the surface 
 in places, or even issue forth as a spring, and the proximity of 
 the comparatively warm water may keep the outcrop warm enough 
 not to freeze. In a porous cavernous gozzan it is easy to imagine 
 the existence of slow currents of the air which would have the 
 same effect. 
 
 The fact of a vein often being a channel of water will also 
 explain the rising of vapours from lodes under certain favourable 
 conditions of the atmosphere. 
 
 Where the surface is cultivated and the natural springs are 
 tapped by adit levels or other mine workings, these appearances 
 cannot be looked for to any great extent ; and it is not unlikely 
 that the old miners, who have handed us down traditions con- 
 cerning the signs of mineral veins, were keener observers of 
 nature than some of their successors, just as the savage may be 
 guided by marks which do not catch the eye of the civilised 
 traveller. 
 
 Old Workings, Slag Heaps, Ruins. Signs of old workings, 
 such as pits and rubbish-heaps, often tell useful tales. When 
 workings were shallow, miners put down shafts in close proximity, 
 and the line of a series of shafts and rubbish-heaps will give a 
 fairly correct idea of the strike of a lode. The rubbish-heaps 
 will show what was the ore worked, and with what it was asso- 
 ciated. 
 
 It even happens that mining refuse, thrown away as worthless 
 in the days when dressing appliances were crude and rough, will 
 pay for being worked over again. On the other hand it is not safe 
 
 * Wendt, " The Pyrites Deposits of the Alleghanies," Eng. Min. Journ., 
 vol. xli. (1886), p. 408. 
 
PROSPECTING. ic 9 
 
 to conclude that, because it paid to work a mine some centuries 
 ago, the same ore will yield a greater profit or even be worth 
 working nowadays. The change in the value of the precious 
 metals, and the change in the remuneration of the labourer, must 
 be duly weighed before a decision can be arrived at. 
 
 It is important to ascertain why the old mines were abandoned. 
 If no good reason, such as a sudden inrush of water, or the break- 
 ing out of a great war, for instance, can be assigned for the stop- 
 page, it is usually safe to assume that no great riches have been 
 left in sight ; statements to the contrary must be very carefully 
 sifted. 
 
 Minerals that were at one time worthless or even regarded as 
 obnoxious, such as nickel and cobalt ores, or zinc blende, become 
 valuable by the discovery of new or improved processes of manu- 
 facture or smelting. An instance of this kind has occurred quite 
 lately. Some forty years ago the outcrops of beds of impure car- 
 bonate of manganese in North Wales were worked for the black 
 oxides, the gozzans, in fact, which had been produced by the 
 weathering of the deposit near the surface. The undecomposed 
 carbonate was at that time of no value and was carefully separated 
 by cobbing and rejected ; and the workings had to be abandoned 
 when the black oxide diminished in quantity at a shallow depth, 
 and was replaced by unweathered ore. Owing to the use of ferro- 
 manganese in making steel, the carbonate can now be utilised, 
 and the ore is regularly mined and sent to the blast furnaces to 
 be smelted with iron ore. 
 
 On the other hand the discovery of a new process may be the 
 means of causing a mine to be unprofitable. The discovery by 
 Weldon of a method of regenerating the oxide of manganese used 
 in making bleaching powder, seriously affected manganese mining 
 by lessening the demand for the ore. 
 
 Old mine plans, reports, and deeds should be consulted when 
 available ; and information should be sought from official geological 
 surveys and mining records when they exist, as they do in this 
 country. A prospector told me a few years ago that he missed 
 securing some manganese properties in North Wales, from not 
 being aware that a government geological map of the district had 
 been published, showing some of the outcrops of the manganiferous 
 bed. 
 
 Slag heaps afford indirect evidence of mining, and like old 
 rubbish-heaps may occasionally be worth smelting. The most 
 notable instance of late years has been the profitable treatment 
 of such heaps at Laurium, in Greece. 
 
 Ruined cities, or other indications of a country having been more 
 thickly populated, are sometimes adduced as proofs of its mineral 
 wealth. Where it is possible to show, from remains found in the 
 towns or encampments, that the inhabitants were engaged in 
 mining or smelting operations, the prospector may fairly lay stress 
 
no ORE AND STONE-MINING. 
 
 upon evidence of this kind. It has often been supposed that some 
 of the old entrenchments in Cornwall were made for the protec- 
 tion of diggers or smelters of alluvial tin ore ; and after the careful 
 explorations of Mr. Theodore Bent at Zimbabwe, in Mashonaland, 
 most persons will be disposed to agree with him that this old city 
 and its fellows owed their existence to gold mining. 
 
 Names of Places. Local names may sometimes supply in- 
 formation, either by denoting some natural feature connected with 
 the deposit, or by recording in some way the existence of mine work- 
 ings. They will be found in all languages, and I need only give a few 
 instances. '-Cae Coch," near Trefriw, in 'Carnarvonshire, means 
 the " red field," from the chalybeate springs, which are due to the 
 existence of a bed of iron pyrites now being worked. " Graig 
 Goch " or " red rock," a name which is not uncommon for mines 
 in Wales, denotes no doubt that the vein was discovered by a red 
 ferruginous outcrop, and so does the name " Fron Goch " or " red 
 breast." Red Mountain, near Birmingham, Alabama, owes its 
 name to the outcrop of an important bed of iron ore. " Glasdir," 
 meaning " blue ground," is the name of a copper mine in North 
 Wales. I cannot help suspecting that the locality was so called 
 in consequence of the blue colour given to rocks or stones by 
 coppery minerals derived from chalcopyrite near the surface. 
 " Balmynhir " or the " diggings at the long stone," denotes work- 
 ings for tin in the neighbourhood of a " menhir " or erect stone in 
 Cornwall. Sometimes the substance is named, as in the words 
 Tincroft, Stahlberg (steel mountain), Porto Ferraio (iron port) in 
 Elba, Gebel Zeit (oil mountain) on the shores of the Red Sea, 
 Yenang-yaung (Creek of oil), the site of the petroleum wells in 
 Burmah. The names Leadhills (Scotland), Bleiberg (Germany), 
 and Gebel-el-Kohol (Tunis), all have the same signification, and 
 have been given from the existence of workings for lead ore. 
 " Al maden " means " the mine," and turning from Spain to our 
 own country, we find " Minera," near Wrexham, with a similar 
 signification given in this case by the Romans, instead of the 
 Moors. The Smoky Mountains,* in North Carolina, were called 
 by the Indians " Unaka," from their word " TJnakeh," meaning 
 " white," because they obtained white kaolin from them. 
 
 Salt is indicated by the prefix " Sal," " Salz," or its equivalent 
 " Hall," in numerous names of places. 
 
 The German word for miner, "Bergmann" i.e., mountain 
 man or highland er reminds us that the old ore-seekers were 
 hillmen, and found their treasures among the mountains, and we 
 constantly find the word " Berg " (mountain), or its equivalent in 
 other languages, forming part of the names of mines or mining 
 towns. Schneeberg, Marienberg, Freiberg, in Saxony, are 
 instances, and of recent date we have Mount Morgan in Queens- 
 
 * W. B. Phillips, "Mica Mining in North Carolina/' Eng. Min. Journ., 
 vol. xlv. (1888), p. 398. 
 
PROSPECTING. 
 
 ITI 
 
 land, and Broken Hill in New South Wales. In the list of 
 copper mines of South Australia* I find no less than twenty-six 
 names of mines beginning with " Mount," in addition to others 
 containing the word " hill " or " knob." 
 
 Other names refer to mining or smelting operations. The 
 village of Pestarena, near Monte Rosa, was evidently so called 
 from the crushing of gold ore in the days of the Romans. 
 " Cinderford," in the Forest of Dean, points to old heaps of iron 
 slag, and such a name as " hammer pond," in the Weald of Kent 
 and Sussex, likewise tells us of iron working in days gone by. But 
 no stress should be laid upon names ; they afford at most an indica- 
 tion of the existence of a mineral, without any evidence of its 
 value at the present day. 
 
 Divining Rod. Belief in the divining rod, or dowsing rod, 
 has not died out completely even in Cornwall, where one still 
 
 FIG. 92. 
 
 meets with educated persons who profess to be able to discover 
 mineral veins by the dipping down of the forked twig when they 
 walk across them. 
 
 Fig. 92, reduced from Agricola,t shows old German miners 
 searching for veins with the rod. 
 
 Dipping Needle. In the special case of magnetic iron we have 
 a safer guide. In Sweden a magnet, suspended so that it can dip 
 
 * H. Y. L. Brown, "A Record of the Mines of South Australia." 
 Adelaide, 1890. 
 
 t J)e re Metallicd, Basle, 1556, p. 28 ; and Brough, " Cantor Lectures on 
 Mine Surveying," Jour. Soc. Arts, vol. xl. (1892), p. 803. 
 
112 
 
 ORE AND STONE-MINING. 
 
 in any direction, is regularly used for tracing masses of magnetic 
 iron ore, even when concealed by some thickness of drift or some 
 depth of water; when the lakes are 
 frozen over in winter, this kind of pro- 
 specting is easy. 
 
 The miner carries his compass care- 
 fully over the ground, and on approach- 
 ing magnetic ore the needle dips towards 
 it ; the amount of dip increases, until at 
 last, when standing directly over the 
 deposit, the needle becomes vertical, and 
 remains so as long as there is a strong 
 mass of ore underneath it. The boun- 
 dary of the deposit can thus be laid down 
 on a map with some degree of accuracy. 
 The modification of the Swedish dipping 
 needle shown in Fig. 93, borrowed from 
 Brough,* has been adopted in the United 
 States. Improved methods devised by 
 Brooks, Thalen, and Tiberg are described 
 by the same author. 
 
 Qualifications of the Prospector. 
 From the above observations it will be 
 seen that the miner is greatly aided in his 
 search by a variety of natural indications ; 
 
 but in a new and unsettled country the physical difficulties of 
 travel are often so great, that strength of body and the capability 
 of supporting fatigue and hardships become some of the most 
 important qualifications of the prospector. He should have 
 a general knowledge of geology, and understand mineralogy 
 sufficiently to recognise all the common and valuable minerals 
 and their ordinary associates, and to confirm his opinion by 
 simple tests. The pick, shovel, and pan should be handled with 
 ease, as well as the rifle and the gun. Keen and good eyesight is 
 a sine qud non ; a myopic prospector would fail to recognise 
 natural features, and a colour-blind person would not be struck 
 by important differences of tint. 
 
 The mode of discovering minerals by boring is a subject of so 
 much importance that it requires a separate chapter. 
 
 * A Treatise on Mine Surveying, London, 1891, p. 261. 
 
CHAPTER III. 
 
 BOEING. 
 
 Uses of bore-holes. Methods of boring holes: I. Boring by rotation ; 
 Auger ; Diamond drills. II. Boring by percussion with rods ; Iron 
 rods, wooden rods; Driven wells. III. Boring by percussion with 
 rope ; American system ; Mather and Platt's system. Surveying 
 bore-holes. 
 
 The uses of bore-holes are numerous : 
 
 1. To reach a mineral deposit by a small hole and ascertain its nature, 
 
 depth from the surface, thickness, dip, and strike, with the object 
 of working it if possible. 
 
 2. To ascertain the nature of the subjacent rocks for engineering pur- 
 
 poses, such as their suitability for railways, canals, locks, sewers, 
 or foundations of bridges and buildings. 
 
 3. To obtain liquids, such as ordinary water, mineral water, brine or 
 
 petroleum, which either rise to the surface, or have to be pumped 
 up from a certain depth. 
 
 4. To make absorbent wells in dry and porous strata. 
 
 5. To obtain gase?, such as natural inflammable gas, carbonic acid gas, 
 
 or vapours containing boric acid. 
 
 6. To drain off gas from rocks, and water or gas from mine workings. 
 
 7. To make passages for conveying power into underground workings 
 
 by steam, water, wire-ropes, or electricity. 
 
 8. To put signal wires or speaking tubes into underground workings. 
 
 9. To introduce cement into unsound foundations in order to strengthen 
 
 them, and also into mine-workings in order to dam back water. 
 
 10. To sink holes for lightning conductors, house-lifts, or piles. 
 
 11. To sink mine shafts. 
 
 The methods of boring holes for these purposes are : 
 
 I. By rotation. 
 II. By percussion, with rods. 
 III. By percussion, with ropes. 
 
 I. BORING- BY ROTATION. Auger. Soft rocks, such 
 as clay, soft shale, sandy clay, and sand can be bored by an 
 open auger (Fig. 94), like the well-known carpenter's tool. 
 
 The mode of working consists* in twisting the tool round by 
 means of a cross-head or spanner, and lengthening it as the 
 hole is deepened. The lengthening rods are made of wood or 
 iron, the iron ones being i|- inch gas-pipe, with screwed pin 
 
 * Darley, "Artesian Wells," Engineering, vol. xxxix. (1885), p. 683. 
 
 II 
 
ii4 ORE AND STONE-MINING. 
 
 and box ends welded on. Even when iron rods are used, some 
 made of pine, 4 inches by 4 inches, are added in order to take 
 off part of the heavy weight by their buoyancy in water. For 
 raising the rods an iron or wooden derrick is employed, such as is 
 
 FIG. 94, FIG. 95. 
 
 shown in the figure 95. It is 30 feet high, so as to give room for 
 pulling up a rod of the usual length of 25 feet, which is drawn 
 up by means of a crab- winch with a ij- inch iron or steel wire 
 rope. The winch is worked by hand or horse-power as required. 
 The top rod is made of square iron, and the cross-head or capstan 
 spanner can be fixed to it at the height most convenient for 
 handling. 
 
BORING. 
 
n6 
 
 ORE AND STONE-MINING. 
 
 The process of boring consists in turning the rod by t\vc 
 men at the capstan until the working tool has filled itself; it has 
 then to be drawn up and emptied. In drawing up, each rod has 
 to be unscrewed and taken off, and the process is reversed when 
 the tool, after having been cleaned out, is again lowered. 
 
 In favourable strata holes are bored 400 feet deep at the 
 rate of 25 feet a day by this method ; it is obvious that, owing to 
 the time occupied in raising and lowering the rods, the first 
 part of the boring is performed at a much greater speed than the 
 last. 
 
 In order to obviate the loss of time which ensues in raising and 
 lo Bering the rod, for the purpose of extracting the contents of the 
 auger, a current of water may be sent down through the hollow 
 rod, and made to ascend in the annular space be- 
 FIG. 97. tween it and the side of the hole with sufficient 
 velocity to carry up the debris. 
 
 Fig. 96, again borrowed from Darley,* shows 
 the derrick and general arrangement of the 
 plant : a is the boring rod made of 2\ inch (in- 
 ternal diameter) gas-pipe or lap-welded iron pipe, 
 in lengths of 25 feet. The separate rods are 
 joined, as shown in Fig. 97, by screwed spigot 
 5 and socket connections whicn are riveted on. 
 
 The short topmost piece of rod b (Fig. 98), 
 carries the chamber c, at the base of which the 
 head of b can revolve freely. On the same rod b 
 is keyed the spur-wheel d. This is actuated by 
 the pinion e upon the vertical shaft /, which re- 
 ceives its motion from the horizontal shaft h 
 (Fig' 96), through a belt and the mitre wheels g. 
 The boring rod is driven at a speed of 80 to 
 100 revolutions per minute. It is easy to under- 
 stand from the figure how the rope drums,/ are 
 worked from the same shaft h at slow or high 
 speed by using one or other of the two clutches 
 upon this shaft. Water is pumped into c by a 
 hose, descends the rod, and passing through the bit ascends with 
 the sludge and chips of rocks. 
 
 As the bit and rods descend, the carrier under the spur-wheel 
 d follows them, and also the pinion e, which is loose upon the 
 square shaft/. 
 
 Fig. 99 represents a favourite form of cutting tool or boring 
 bit, which begins by making a small hole and then speedily 
 enlarges it to the full diameter. 
 
 As the lining tubes are usually 7 inches in diameter, the 
 annular space between the tube and the boring rod is large, 
 
 * Op. dt. p. 684. 
 
BORING. 
 
 117 
 
 and this is diminished by adding a lagging of wood (shown in 
 Fig- 97) f r tne purpose of increasing the velocity of the upward 
 current and so promoting the discharge of the debris. 
 
 The rapidity with which some holes are bored by this machinery 
 is considerable. Mr. Darley mentions that a hole had been bored 
 
 FIG. 98. 
 
 FIG. 99. 
 
 to the depth of $00 feet, and cnsed all the way in nf days, 
 including the time occupied in putting up the derrick. 
 
 Another rotatory method for sinking wells or exploring in soft 
 or moderately hard ground consists in revolving the casing or 
 lining tube, which is shod with hard steel teeth,* whilst a stream 
 of water is forced down through it ; the water ascends in the 
 narrow annular space between the tube and the sides of the hole. 
 The core is gradually washed away by the descending current, 
 and the inventors claim that any clay carried up by the water 
 forms in time a protecting shell to the sides of the bore-hole, 
 if composed of very loose strata. They even send down clay, 
 chaff, bran, or cement by the tube for the express purpose of 
 its making a resisting lining shell. 
 
 In the alluvium of the Mississippi at New Orleans a 7 -inch 
 well was bored in this manner 500 feet deep in 48 hours. 
 
 For boring holes not exceeding 40 or 50 feet (i2toi$ in.) in depth, 
 which may be required for geological surveys or for investigating 
 shallow-lying deposits, a convenient portable set of tools has been 
 arranged by Messrs. Van den Broeck and Rutot."j* It consists of 
 the following parts : (i) a series of rods 4 feet i inch (i'2$ m.) 
 long, which can be put together by screw joints; (2) either a 
 chisel cutter or a twisted auger, for doing the actual boring ; and 
 (3) a handle which is attached to the topmost rod. As accessory 
 
 * Encyclopedia of Well- Sinking Appliances. The American Well Works, 
 Aurora, Illinois, U.S.A., 1886, p. 183. 
 
 t " Un nouvel appartil, portatif de sondage pour reconnaissance rapide 
 du terrain," Bulletin Soc. tidye de Geologic, toine ii. (Annee 1888), 29 Mai. 
 
Tl8 
 
 ORE AND STONE-MINING. 
 
 FIG. 100. 
 
 parts, there are spanners for unscrewing the rods, a key for support- 
 ing the rods during this operation, and a second handle which can 
 be fixed on any part of the line of rods if more force is required 
 for the work. By a very ingenious clip, each joint can be so fixed 
 that it cannot become unscrewed during the process of boring. 
 The diameter of the large auger is if inch (45 mm.) and the 
 cutting part has two wings which are of service in penetrat- 
 ing the ground. The chisel is used for hard seams, such as 
 ironstone, grit, and beds containing fossils or pebbles ; like the 
 auger, it is if inch across. The apparatus is very portable, 
 for no part is more than 4 feet i inch long ; each rod weighs 4-4 
 Ibs. (2 kil.), and the total weight of all the plant required for 
 making a boring 40 feet deep is only 64 Ibs. (29 kil.). 
 
 Diamond Drills. The most important kind of boring by 
 rotation is done with the diamond drill. The working part of 
 the drill consists of the so-called crown, which 
 is a short piece of tube made of cast steel, at 
 one end of which a number of black dia- 
 monds are fastened into small cavities. The 
 crown is screwed on to wrought-iron pipes, 
 vhich constitute the boring rod. This is 
 made to rotate, and the result is that an 
 annular groove is cut at the bottom of the 
 hole, leaving a core which often breaks off of 
 itself, is caught by a little shoulder, and 
 brought out with the rod (Fig. 100).* In 
 places where it is not necessary to make any 
 verification of the rocks traversed, the crown 
 may be arranged with diamonds in the centre 
 also, so that the whole of the bottom of the hole is ground away. 
 The debris in either case are washed away by a stream of water, 
 which is forced down the tube and flows up 
 the sides of the hole. 
 
 In order to prevent capital from being 
 locked up in a stock of large crowns, Messrs. 
 Docwra sometimes fix the diamonds in steel 
 plugs, which will fit holes in any ring. The 
 diamonds can then easily be taken out of one 
 crown and placed in another without re- 
 setting. 
 
 The crown represented in Fig. 101 was the 
 largest employed at the deep boring at Northampton. It was 
 screwed to a tube 30 feet long (Fig. 102), which enabled cores of 
 almost that length to be cut without withdrawing the tool. The 
 object of the open sediment-tube above the core-tube was to catch 
 
 Fro. TOI. 
 
 * Eun^on, " On a Deep Boring at Northampton," Min. Proc. Inst. C.E., 
 vol. Ixxiv. (1883), p. 270. 
 
BORING. 
 
 119 
 
 FIG. 102. 
 
 FIG. 103. 
 
 any coarse particles too heavy to be carried up by the water, as 
 well as any fragments falling from the sides of the hole. 
 
 Though pieces of the core of fen broke off of themselves and came 
 up in the tube, it was necessary to use the 
 extractor (Fig. 103) ; it consisted of a ring A, 
 which was screwed by a few threads to the 
 core-tube in the place of the crown. On 
 reaching the bottom of the hole the screw- 
 ing-up was continued, and the descent of the 
 portion C gradually forced down six teeth, 
 such as B, into the position shown by B', 
 gripping the core tightly. If not broken off 
 completely by this action, it gave way when 
 the tube was pulled, and came up inside it. 
 
 The " Dauntless" (Fig. 104) is one of the 
 diamond drills made by the Bullock Manu- 
 facturing Company, of Chicago, for . boring 
 prospecting holes, and is capable of drilling a 
 2 -inch hole to a depth of more than 2000 
 feet, and furnishing cores of ly^th inch in 
 diameter. Cores show- 
 ing visible gold have 
 lately been brought up 
 from a hole 2500 feet 
 deep, bored by one of 
 these drills near J ohan- 
 nesburg. 
 
 The machine is con- 
 structed as follows : A 
 is one of a pair of cylin- 
 ders, driven by steam 
 or compressed air, which 
 work the bevel wheel 
 
 B by gearing. The feed-screw CC can slide readily up and 
 down through B ; but as B carries a feather lying in a slot in C, 
 the latter is driven round when the former rotates. D is the 
 crown set with diamonds, screwed on to the first piece of boring 
 tube C", attached to C by the chuck C'. The hose, E, coming 
 from a special pump, brings in a continuous supply of water 
 which passes down C and comes out through D. F', F", F"', 
 and G', G", G'", constitute the differential feed-gear for causing 
 the feed-screw C, and consequently the bit D, to descend as the 
 hole is deepened. 
 
 F 7 , F", and F'" are connected with B so that they revolve when 
 it does; G', G", and G'" are loose upon the counter- shaft, but any 
 one of them can be made fast to it by operating the clutch H. 
 K is a toothed wheel attached solidly to the bottom of a feed-nut 
 through which C passes ; when K rotates it causes C to ascend or 
 
 riots 1 * 
 
120 
 
 ORE AND STONE-MINING. 
 
 descend. L is a wheel equal in size to K, which it drives when 
 its t-haft is rotated by G', G", or G"'. 
 
 If F'and G' had the same number of teeth each, one revolution 
 
 FIG. 104. 
 
 of B would make one revolution of G', one revolution of L, and 
 one revolution of K ; consequently the feed-nut attached to K 
 would be revolving at the same rate as 0, and C would not descend. 
 In reality G', G", and G'" have a slightly smaller number of teeth 
 than F', F", and i "'; therefore one revolution of F' causes slightly 
 
BORING. i2i 
 
 more than one revolution of G', K moves rather faster than C, and 
 C descends slowly. As arranged in this particular case, the gear 
 F G' causes C to descend i inch for every 300 revolutions, 
 the gear F" G" gives a feed of i inch for every 450 revolutions, 
 and F'" G'" a similar feed for 750 revolutions. The driller is 
 thus enabled to regulate his feed to the hardness of the rock 
 bored. In practice these three speeds of advance have been found 
 sufficient. 
 
 M is a drum which is used for hoisting the rod out of the hole ; 
 N is the hinge upon which the whole of the boring head can be 
 turned, so as to leave the mouth of the hole perfectly free while 
 raising or lowering rods. O is the thrust register, upon which is 
 indicated by a dial the resistance exerted by the rock against the 
 bit. This is an addition of great importance, for by watching the 
 indicator the driller can detect changes in the hardness of the 
 strata passed through, and can measure the exact thickness of the 
 hard and soft beds before he has seen either the cuttings or the cores. 
 The thrust register prevents the possibility of drilling through a 
 bed of coal or other mineral without its being noticed, as has 
 happened when the seam was so soft that it failed to furnish a 
 core. The rod is lengthened as the drilling proceeds by screwing 
 on piece after piece between C' and the topmost rod projecting 
 above the hole. 
 
 Mr. Bullock has recently brought out a contrivance by which 
 the core can be drawn up through the hollow boring rods without 
 removing them from the hole. The immense saving of time 
 effected in this manner is of supreme importance when boring at 
 great depths. 
 
 The large rock drill used by the American Diamond Rock 
 Boring Company,* for putting down holes to a depth of 2000 
 feet, consists of a 20 horse-power boiler with two oscillating 
 6-inch cylinders and the necessary gearing for working the drill, 
 all mounted on a carriage, so that the whole machine is readily 
 moved from place to place. The feed is effected by gearing, or 
 by hydraulic pressure, a 2 f -inch crown is employed, leaving a 
 2-inch core. Each separate drill rod is 10 feet long. The total 
 weight of the machine is about four tons. 
 
 The newf Victorian Giant Drill, said to be the largest and most 
 powerful drill in Australia, contains some improvements suggested 
 by experience. The cylinders are 7^ inches in diameter, and are 
 made stationary, because the heavy vibrations of oscillating 
 cylinders are imparted to the boring rods and diamond bit, and 
 do harm to the machinery. The winding drum has a friction 
 pulley and a brake, which enable the rods to be lowered without 
 working the engine, and so prevent unnecessary wear and tear. 
 
 * Eiifj. Min. Jovr., vol. xlviii. (1889), p. 569. 
 
 t Victoria, Annual Report of the Secretary for Mines for the Year 1889. 
 Melbourne, 1890, p. 35. 
 
122 ORE AND STONE MINING. 
 
 Various parts are strengthened, and there is an arrangement for 
 working the steam expansively. 
 
 This method of boring is expensive. During the year 1889, 
 the cost of prospecting for gold by diamond drills in Victoria* was 
 i os. 3d. per foot bored, exclusive of the wear and tear of 
 diamonds, taking the average of a total 18,454 feet bored. The 
 cost for the wear and tear of diamonds for 30,294 feet bored in 
 search of coal and gold is put down at ^6000, or nearly 43. per 
 foot. In the borings executed by the Government of New South 
 Wales,t the cost for diamonds is very much less, varying as a rule 
 from is. to 28. per foot. This may probably be accounted for by 
 the fact that most of the New South Wales bore-holes were made 
 in the comparatively soft Carboniferous strata, whilst some of 
 the bore-holes for deep leads in Victoria had to traverse hard 
 basalt. 
 
 The cost at Broken Hill, where a boring 3 inches in diameter 
 was carried from 1122 feet to a depth of 1880 feet in 1889, was 
 i 93. io|d., or, roughly speaking, 303. per foot, exclusive of 
 office salaries, store wages, rent, and the Superintendent of 
 Drills' travelling expenses. The rocks traversed were gneiss, 
 mica schist and quartzite, sometimes garnetiferous. The average 
 rate of boring was only 5-7 1 inches per hour, whilst in the sandstone 
 and shale of the Carboniferous strata there was a progress of 9 
 to 31 inches per hour, at a cost (exclusive of the items mentioned 
 above) of 6s. 2d. to i8s. 4d. per foot. The average working cost 
 of 7854 feet bored by the Department of Mines, New South 
 Wales, in 1889, including all expenses, was 143. 3^-d. per foot. 
 Of the total 7854 feet, no less than 7096 were in strata of Car- 
 boniferous age, and only 758 in metamorphic schists ; the holes 
 were from 2-^ inches to 4 inches in diameter. 
 
 With reference to the rate of boring, it must be remembered 
 that the figures given refer to the speed obtained while the 
 machine was at work, but the average amount of deepening of 
 the hole at Broken Hill during the year was little over 2 feet per 
 day. Omitting Sundays, there were 313 working days. Only 
 199, or less than two-thirds, were employed in boring; of the 
 remainder, 86 were occupied in repairing, 15 in reaming, 4 by 
 delnys, 9 by holidays ; the working day was eight hours. 
 
 The amount of core obtained at Broken Hill compared with 
 the total depth bored was as much as 97 J per cent., and the average 
 for the total 7854 feet referred to above was 89-33 per cent., a 
 very excellent result. 
 
 Small diamond drills, which will bore in any direction, and 
 which are driven by hand, compressed air, or electricity, are 
 largely used underground for prospecting. The hand drill of a 
 
 * Op.cit.,p. 63. 
 
 t Annual Report for the Dzpnrtmant of Mines, New Sjuth Wales, for thz 
 Year 1889. Sydney, 1890, p. 139. 
 
BORING. 
 
 123 
 
 Swedish boring compnny* gives cores | inch in diameter. Ex- 
 ploration by these little machines is very decidedly cheaper than 
 by driving or sinking by hand in hard rocks, and fully ten times as 
 quick. On the other hand, the ground is not opened out as it would 
 be by a shaft or drift, and the sample furnished is but small. 
 
 Several good veins have been discovered by the aid of the little 
 hand-machine in Scandinavia for instance, a copper lode 15 feet 
 (4-5 m.) wide at Roraas, and iron lodes from 32 to 65 feet 
 (10 m. to 20 m.) wide at Dcinnemora and Persberg. 
 
 The hand-power drill of the Bullock Manufacturing Company, 
 Chicago, is a somewhat similar little machine, and it is said to be 
 
 FIG. 105. 
 
 capable of boring a hole of if inch diameter, with a i-fy inch 
 core, to a depth of 400 feet. 
 
 Machines driven by compressed air are often employed at 
 ore mines in the United States for exploratory purposes. 
 Fig. 105 shows the Little Champion prospecting drill. Two 
 inclined cylinders drive a horizontal crank-shaft, which works 
 bevel gear, causing the drill to revolve. At the same time a 
 counter-shaft is likewise Fet in motion, and this effects the 
 advance of the drill by driving the feed screw, in the manner 
 already explained in the description of the " Dauntless" machine 
 
 * Nordenstrora, " DieDiamantbohrnoaschine mit Hanrlhetrieb," B. u. h. 
 Z. 1889, pp. 389 and 449 ; and Petiton, Bull. Soc. Ind. Min., $e Seiie, vol. 
 iii. (1889), p. 1395. 
 
 t EHCJ. Min. Jour., vol. xxxiii. (1882), p. 119. 
 
124 ORE AND STONE-MINIIIG. 
 
 (p. 120). The feed-screw and its connections are carried by a 
 swivel-head, and this can be turned so as to drill holes at an 
 angle. The drum shown above the cylinders is used for hoisting 
 out the drill-rods by a rope. The rods are lap-welded iron tubes 
 1 1 inch in diameter, fitted with a bayonet joint. 
 
 Another light portable prospecting drill for underground work 
 is represented in Fig. 106.* It is intended for drilling holes 
 i J inch in diameter to a depth of 150 feet. The cores which it 
 yields are J inch in diameter. It has double oscillating cylinders 
 3 J inches in diameter, with 3^ inches stroke, which are run up to 
 a speed of 800 revolutions a minute. The drill can be set to 
 bore in any direction by turning the swivel-head on which it is 
 carried. 
 
 The Sullivan prospecting drill is a diamond borer driven by an 
 electric motor on the same frame as the drill. The motor also 
 works the force-pump. The feed is not by toothed wheels as 
 shown in the figures, but by friction gearing. It will bore at any 
 angle to a depth of 300 feet. 
 
 Georgi'sf electric diamond drill, primarily intended for boring 
 holes for blasting, can also be employed for prospecting under- 
 ground. 
 
 Substitutes for Diamonds. Olaf Terpt uses emery instead 
 of diamonds. In some cases he puts in the fragments of emery 
 loose at the bottom of the hole and allows them to wedge them- 
 selves into grooves in the boring crown, which is made of soft 
 metal. Another plan is to make the boring crown entirely of 
 emery. The speed of rotation is three or four times as great as 
 with diamonds, and holes can be bored from |- inch (20 mm.) 
 to 3 feet 4 inches (i m.) in diameter. Beal bores with small 
 chilled cast-iron shot, which are dropped into the hole while a 
 wrought-iron tube is revolving in it. The debris are carried up 
 by water, and the cores are extracted in the ordinary way. 
 
 II. BORING BY PERCUSSION WITH RODS. 
 
 Iron Bods. The rods are either of iron or wood. In France 
 preference is given to iron, and the following details relate to 
 modes of construction now employed by M. Paulin Arrault, the 
 well-known boring engineer of Paris. 
 
 The actual boring apparatus consists of the cutting tool, the 
 rods, and the driving machine ; but in addition it is necessary to 
 
 * Eng. Mln. Jour., vol. xxxiii. (1882), p. 273. 
 
 t Jahrb.f. d. Berg- und JTiittenwesen im K. tfachsen, 1890, p. 95. 
 
 J Olaf Terp's " Bohrmaschine mit Schmirgelbohrkrone," B. u. h. Z., 1890, 
 
 P- 4i5- 
 
 The figures are copied by permission from M. Arrault's work, Outils 
 et proctdes de Sondaye. Paris, 1890. 
 
BORING. 125 
 
 have clearing tools, and appliances for remedying accidents, lining 
 the bore-holes, and obtaining samples of the rocks traversed. 
 
 Cutting Tools. The actual cutting tool is usually a chisel (Fig. 
 107) of some kind ; for soft rocks the edge is straight ; for hard 
 rocks there are wings to guide the tool and keep 
 the hole vertical, or even special guides above FIG. 107. 
 it. For diameters not exceeding 40 inches (i m.), 
 there is usually only one chisel; but the actual 
 cutting blade is sometimes made in a separate piece 
 fastened by gibs and cotters to the tool carrier ( Fig. 
 1 1 8). In boring larger holes the chisel is made of 
 two, three, or four separate blades. 
 
 Boring Rods. The boring rods are made of iron 
 of square section. The usual mode of connection 
 is by a screw-joint such as is shown in Fig. 108, 
 care being taken to have all the bars alike, so 
 taht any two bars can be screwed together. M. Arrault prefers 
 to have a connecting socket (Fig. 109). The ordinary rods have 
 a thread at each end, to one of which is screwed a socket or sleeve 
 which is fixed by a pin. This socket then receives the end of 
 another rod, which is screwed up until both ends meet. When 
 the thread of a socket becomes worn, it is taken 
 off and put on to the other end of the rod ; in a FIGS. 108 & 109. 
 similar manner, if the thread of a rod is worn, 
 the socket may be screwed on to it and the un- 
 worn end used in the process of jointing and 
 unjointing. The rods are generally screwed up 
 to the right and are turned in that direction ; 
 but in special cases it may be necessary to have 
 the sockets fixed by two pins, or to have a 
 special joint or a left-handed thread. 
 
 The height of the tower, derrick, or shears 
 erected above the bore-hole should be some 
 multiple of the length of the rods, so as to be able to detach or 
 attach two or three lengths at a time, instead of having to make 
 and unmake every joint. 
 
 FIG. 1 10. 
 
 FIG. in. 
 
 FIG. 112. 
 
 Arrault's rods vary in length from i foot 8 inches (0-50 m.) to 
 20 feet (6 m.), being usually an exact number of metres, and in 
 size from J inch (22 mm.) to 3^ inches (90 mm.) on the side. 
 
126 ORE AND STONE-MINING. 
 
 They have two shoulders at each extremity, so that the upper one 
 can be used with the lifting hook, Fig. no, when the lower is 
 resting upon the key, Fig. in. 
 
 A cap such as Fig. 112, may be screwed on and used instead of 
 the lifting hook for raising the rods by the rope. 
 
 Working the Rod. The up-and-down movement of the rods may 
 be obtained in various ways. For depths not exceeding 60 to 80 
 
 FIG, 113. 
 
 feet, nothing can be simpler than the device shown in Fig. 113. 
 The man at the windlass raises the rods by turning the handle, and 
 the master borer detaches them and causes them to fall by simply 
 pressing down the end of the hook, which he holds in his right 
 hand. The chain is lowered, the hook put in, the rods are raised 
 by the winch, and then again allowed to fall, the master borer 
 taking care to turn them a little each time. 
 
BORING. 
 
 127 
 
 Fig. 114 shows the principal tools supplied by Arrault for a 
 small boring. 
 
 For greater depths a lever has to be employed, the rods being 
 suspended at one end, while the other can be pressed down by 
 men using their hands or feet. The spring pole is another 
 arrangement ; the pole is pulled down to make the stroke, and 
 its elasticity lifts the rod again. The length of the stroke can be 
 
 FIG. 114. 
 
 I, guide tube; 2, bit or chisel with wings; 3, straight bit or 
 chisel : 4, ordinary open scoop or wimble ; 5, scoop or wimble 
 with auger; 6, closed scoop ; 7, sludger with ball valve ; 8, bell- 
 screw or screw grab ; 9, auger ; 10, combination bit and sludger 
 with ball valve; n, combination auger and sludger with ball 
 valve; 12, boring rod; 13, matching piece; 14, wrench for un- 
 screwing rods ; 15, matching or lengthening piece ; 16, clamp; 
 17, clamp with eye ; 18, wrench ; 19, retaining or supporting key ; 
 20, cap ; 21, tiller ; 22, double wrench ; 23, scraper; 24, picker. 
 
 rendered uniform during the boring by means of a screw in a 
 swivel-head at the top of the rod. 
 
 With deep holes, and especially those of large diameter, steam 
 machinery has to be employed for working the rod. Arrault 
 frequently uses a winch driven by steam. The chain to which 
 the rods are attached passes over a pulley hung from a derrick 
 and is coiled on a drum, which is loose upon the main axle of the 
 winch ; it can be thrown in and out of gear by a clutch moved by 
 a lever. It is easy therefore to raise the rods by working the 
 winch, and then let them drop by simply releasing the clutch. 
 
123 ORE AND STONE-MINING. 
 
 Occasionally a direct-acting engine is placed immediately 
 above the bore-hole, but a commoner arrangement is to employ a 
 single-acting cylinder with its piston acting at one end of a 
 beam, while the rods are attached to the other end. A favourite 
 plan also is to actuate the beam by a connecting rod worked by a 
 crank. 
 
 Process of Boring. The actual machinery has now been 
 described, and the mere boring appears to be a very simple 
 matter, consisting only in lifting the rod a little and allowing it 
 to drop, after turning it slightly before each stroke. Never- 
 theless the process of putting down a bore-hole is far more com- 
 plicated than it might seem, for there are numerous operations 
 which take up much time. In the first place the debris must be 
 removed by a clearing tool, and before this can be lowered the 
 cutting tool must be taken off. The swivel-head is disconnected, 
 and a cap screwed on ; a length of rod is now drawn up by a hand 
 or a steam windlass, the retaining key is put under a shoulder, 
 and the joint unscrewed by another key. It is well to have as 
 many caps as there are lengths to be drawn up, and then each 
 length can be suspended in the boring house or derrick. 
 
 As soon as the hole is free the clearing tool is lowered, 
 either by the rods in precisely the same way as the boring chisel, 
 or by means of a rope and windlass. The clearing tool 
 FIG. 115. is usually a hollow cylinder with an ordinary clack or 
 a ball valve (shell pump or sludger) (Fig. 115). It is 
 worked up and down a little till it is filled, and it is 
 then drawn up to the surface and emptied. The opera- 
 tion is repeated if necessary, and the boring is resumed 
 with the rod. Sometimes a cutting blade is added to 
 the sludger so that it bores a little and picks up the 
 debris at the same time. In certain rocks such as 
 marls, it is convenient to have a shell-pump with a 
 lip. It is fixed to the rods, and when it is turned a 
 little as well as moved up and down, it soon fills itself. 
 
 Oeynhauseris Joint and free-falling tools. When a hole of large 
 diameter is being bored, the weight of the rods is so great 
 that much vibration ensues when they are suddenly arrested 
 by the chisel striking against the bottom. Various devices have 
 been contrived for overcoming this difficulty, among which may 
 be mentioned Oeynhausen's sliding joint and three methods of 
 making the tool fall independently of the rod. Oeynhausen's 
 contrivance (Figs. 116 and 117) consists of an upper piece a pro- 
 vided with a slot in which the lower piece b can slide ; b is pre- 
 vented from dropping out by a crosshead and carries the boring 
 chisel, whilst a is attached to the line of rods. 
 
 When a down-stroke is made and the chisel strikes the 
 bottom, the piece a slides over b and is therefore but little 
 affected by any jar produced by the blow of the tool. The length 
 
BORING. 
 
 129 
 
 FIGS. 116, 117 & 118. 
 
 1 
 
 t 
 
 of the stroke is arranged so that the top of the slot will not 
 descend far enough to touch the crosshead ; a is then raised once 
 more and again catches the crosshead. 
 One of the simplest arrangements 
 for making the tool fall independently 
 is the sliding joint shown in Fig. 118. 
 The piece supporting the boring tool h^ s 
 two wings (Fig. 119) which rest upon 
 shoulders, at the top of a long slot in 
 a cylinder attached to the lowest rod ; 
 by giving the rods a sharp turn to 
 the left, the wings lose their support 
 and the tool drops. 
 
 The actual process of boring is 
 carried on in the following manner : 
 The line of rods suspended to a chain 
 is raised by a steam winch. 
 FIG. 119. Steam is then shut off, and 
 the master borer by a sudden 
 twist of the tiller causes the 
 bayonet joint to act; the 
 tool drops and makes its cut. 
 The rods are then lowered, 
 and the slot comes down 
 over the wings which are 
 pressed by the inclined sur- 
 faces at the end on to the 
 shoulders ; the steam is 
 turned on again, and the operations of 
 winding up, stopping, twisting, letting 
 the tool fall and lowering are repeated. 
 The contrivance acts so easily that it is 
 sometimes used even for comparatively 
 shallow bore-holes. 
 
 The free fall is obtained by Arrault in 
 a different manner when the boring is 
 done by a beam (Fig. 120). The tool is suspended 
 from the catch h (Fig. 121). The part ab has a 
 pin i, which lies in an oval hole. While the rods 
 are being lifted the beam strikes a bumping- 
 piece, and their upward movement is suddenly 
 checked ; inertia carries the catch a b up a little, 
 the end a strikes an inclined surface and causes the end b to 
 move outwards and detach the tool. When the rods are lowered 
 the part h hooks itself on without difficulty, and the chisel is 
 raised and dropped. 
 
 This tool requires the boring rod to be guided, for otherwise the 
 hole might not be bored straight. 
 
130 ORE AND STONE-MINING. 
 
 Fig. 122 explains a well-known free-falling tool invented many 
 years ago by Kind.* The head of the actual boring rod is held 
 
 FIG. 1 2i. 
 
 FIG. 122. 
 
 FIG. 120. 
 
 by a click or grapple. When the main rod descends, the resist- 
 ance of the water in the hole checks the sliding disk D ; the jaws 
 J J are opened by the little rod which connects them to D, and 
 the boring part falls and strikes the bottom without any injurious 
 vibrations being communicated to the main rod. When the disc 
 descends further, the head is caught again by the click. 
 
 Accidents. Tools for putting things right in case of accident 
 are numerous, and many of the contrivances which have been 
 invented by engineers are extremely ingenious. 
 
 Among the accidents is a breakage of the rod. If the rods are 
 not caught in any way, a claw called the crow's-foot (Fig. 123) is 
 lowered and turned round till it catches a rod below one of the 
 shoulders ; it is then drawn up. Sometimes it is found that a hole 
 has suddenly deviated from the vertical, owing to a difference in 
 hardness in the rock, which causes the chisel to work more easily 
 on one side than the other. One method of remedying this evil 
 is to fill the bad part with cement, and rebore it very carefully. 
 
 Broken ropes can be caught hold of by tools resembling a cork- 
 screw. The tool shown in Fig. 124 serves to cut a thread upon 
 the end of a broken rod. The position of the broken end is first 
 
 * J. Callon, Lectures on Mining, vol. i., Atla, Plate IX., Fig. 52. 
 
BORING. 131 
 
 ascertained by taking an impression upon tallow or wax, and the 
 cone is then lowered on to it ; by turning it round a thread 
 is cut on the broken end, which can now be raised with the rods 
 and tools attached to it. 
 
 If the cutting chisel is broken, some kind of grasping nippers 
 must be used, and there are contrivances for making them act 
 when they have reached the bottom of the hole. 
 
 Linings. "Where the strata are soft and would fall in, or where 
 it is necessary to shut off the inflow of certain water-bearing 
 beds in order to confine the well to one particular source of 
 
 FIGS. 123 & 124. 
 
 
 FIG. 125. 
 
 FIG. 126. 
 
 supply, the hole has to be lined with a tube. Tubes are made of 
 iron, copper, or wood. This last material is seldom employed 
 nowadays, because it occupies so much space, and because it is not 
 easy to make good wooden tubes. 
 
 Fig. 125 is a tube of riveted sheet iron with sockets fixed on, 
 which enable the joints to be made by screwing. Fig. 126 is a 
 tube with a screwed joint perfectly smooth outside and inside. 
 Copper tubes are advisable when the water, such as that coming 
 from pyritiferous beds, would attack iron and in time eat it away; 
 but this difficulty is also overcome by putting earthenware pipes 
 inside, and filling up the interspace with cement. 
 
 Cores. Though the fragments brought up in the sand-pump 
 will indicate the nature of the rocks which are being traversed, it 
 is often desirable to obtain a core of the actual stratum itself, 
 which will show the direction and amount of the dip of the 
 rocks, and possibly contain fossils and so afford valuable knowledge 
 concerning their precise age. A core is cut out either by rota- 
 tion or percussion. In the former case the tool consists of a 
 sheet-iron cylinder (Figs. 127 and 128) armed at the bottom with 
 
I 3 2 
 
 ORE AND STONE-MINING. 
 
 steel sawing teeth ; in the latter the cylinder is surrounded by 
 four cutting chisels, which chip out a ring and leave a solid 
 cylinder standing. 
 
 The core now has to be detached, and for this purpose various 
 contrivances may be adopted. One of Arrault's tools is shown in 
 Fig. 129. It is a hollow cylinder a attached to the fork b c, with a 
 longitudinal slot containing a sliding bar d, armed with a toothed 
 wedge e, which is prevented from dropping out by the shoulder /. 
 The bar d is further kept in position by the spring g h, fixed at 
 
 FIG?. 127 & 128. 
 
 FIG. 129. 
 
 i 
 
 J 
 
 Section at A B. 
 
 the top of the tube, which presses it against the two outer plates 
 ij and the ring k ; I is a little slot in the spring, and m a small 
 stud upon the bar d. When this tool is lowered over the core 
 and the wedge e touches the bottom of the annular groove around 
 it, the tube slides down and forces the wedge inwards; the 
 weight of the rods causes sufficient pressure to drive the teeth of 
 the wedge into the core and break it off. In the meantime the 
 slot I has passed over the stud m ; the wedge is thus prevented 
 from slipping down, and the core is held till it is drawn up to the 
 surface. 
 
 In order that the direction of the dip may be ascertained from 
 the core, it is necessary to know exactly how it stood when it was 
 
BORING. 
 
 133 
 
 in situ. In Victoria* the rods and the core-breaker are put 
 together at the surface, and all the joints are marked in a straight 
 line with a chisel. The rods are then taken apart, and are care- 
 fully screwed together in precisely the same manner when they 
 are lowered into the bore-hole. If the position of the marks at 
 the surface is noted while the core is being detached, the direction 
 of the dip can at once be determined. To prevent the possibility 
 of error from a movement of the core after it has been detached, 
 it is marked while at the bottom of the hole with a vertical 
 scratch or groove. This is made by a sharp steel point on the 
 gripper as it slides down over the core. 
 
 A method lately invented by Arrault consists in lowering a 
 compass, enclosed in a case made of phosphor bronze, on to the 
 
 FIG. 130. 
 
 FIG. I30A. 
 
 top of the core (Figs. 130 and I3OA). The case has an india- 
 rubber base, with two grooves filled with felt impregnated with 
 a thick ink. The compass case also contains clockwork, arranged 
 like an alarum, which can be made to liberate a catch and so 
 clamp the compass. The compass is lowered by a rope, and suffi- 
 cient time is given to enable it to assume its proper position before 
 
 * Reports and Statistics of the Mining Department, Victoria, for the Quarter 
 ended March j/, 1891, p. 28, with Plaie. 
 
ORE AND STONE-MINING. 
 
 it is fixed by the clockwork. It is drawn up, the 
 core is then extracted, and by means of the ink marks 
 the compass can be put upon the core in precisely the 
 same position as it originally occupied in the hole. 
 
 Instead of using ink marks, some plastic material* 
 such as clay may be lowered on to the top of the core 
 and allowed to remain long enough to take an impres- 
 sion. A clockwork arrangement in a watertight box 
 above the plastic lump sets a magnet fast after the 
 lapse of a given time as before, and when the core is 
 brought up it is placed so as to fit the impressions, 
 the orientation of which is known by the magnet.f 
 
 Wooden Bods. In some districts wooden rods are 
 found more suitable than iron ones. They have been 
 used in Canada, and they are preferred in Galicia. 
 Fig. 131 represents the manner in which the rods are 
 made for boring oil wells in that country. The rods 
 employed in Galicia are of ash, 32 feet 10 inches (10 m.) 
 long, and 2 inches in diameter ; at each end a forked 
 iron coupling is riveted on, terminating by a conical 
 male or female screw, and in the middle are two 
 strapping plates of iron to give more strength and 
 stiffness. To the end of the lowest rod is attached an 
 Oeynhausen sliding joint which carries a sinker bar 
 with the cutting chisel attached to it. The sinker 
 bar is from 20 to 30 feet (6 to 9 m.) long, and weighs 
 from 12 to 15 cwt. (600 to 750 kil.). 
 
 The top of the line of rods is fastened to a chain 
 (Fig. 132) ; this makes three turns round one end of 
 the boring beam, capped for this purpose by a casting 
 with a spiral groove, and is then wound on to a little 
 windlass placed on the beam. The beam receives its 
 up-and-down movement from a connecting rod attached 
 to a crank upon the axle of a wheel driven by a belt 
 from a small steam-engine. I 
 
 After boring, the chain is unfastened, and the rods 
 are drawn up by means of a hemp or manilla rope 
 if inch (45 mm.) in diameter, which is also used for 
 working the sand-pump. The master borer can per- 
 form all the necessary operations while sitting in front 
 of the hole. By means of the rope a he can work 
 the windlass upon which the chain is coiled, and by 
 pulling the lever b he can throw in or out of gear the 
 
 * B. u. h. Z., 1890, p. 205. 
 
 f Reports and Statistics of the Mining Department, Victoria, 
 Quarter ended March j/, 1891, Dip contrivance, p. 28. 
 
 J Syroczynski, " Note sur le forage canadien," Bull. Soc. 
 Jnct.Min., tome iii., 3 Serie. Saint-Etienne, 1889, p. 1417. 
 
BORING. 135 
 
 pulley which drives the drum with the winding rope, and so raise 
 or lower the rods or the sand-pump. The lever c actuates a 
 brake which enables him to stop the machinery, if necessary, and 
 with his left foot he can press upon a pedal e, and so regulate 
 the steam valve, and alter at pleasure the speed of the engine. 
 
 FIG. 132. 
 
 The cord d works a second steam valve. Two other workmen, 
 one at the bore-hole, and the other on a platform 33 feet (10 m.) 
 above him, are shown in the act of unscrewing and putting away 
 the rods. 
 
 During the actual boring, the two assistants stand at the hole 
 and turn the rods, whilst the mnster borer regulates the blow by 
 
136 ORE AND STONE-MINING. 
 
 the cord a which commands the windlass, and the cord d which 
 controls the admission of steam. 
 
 The tower or derrick is about 50 feet (15 to 1 6 m.) high, and 
 1 6 feet (5 m.) square at the base. It is closed in with planks. 
 The adjacent space required for the steam-engine, belts, wheels, 
 &c., is 35 square yards (30 square m.). The end of the beam 
 travels about 20 inches (50 cm.); but owing to the inter- 
 position of the sliding joint the stroke of the chisel is some- 
 what less. There are about 50 to 60 blows a minute. After 
 work has gone on for a time, and the debris begin to accu- 
 mulate, the rods are withdrawn and the shell-pump is lowered 
 by the rope. It is a cylinder 32 feet (10 m.) long, with 
 a valve in the bottom ; it fills itself, it is drawn up, and the valve 
 is opened to discharge the sludge. In consequence of the light- 
 ness of the rods, the conicity of the screw joints, and the skill of 
 the workmen, the various boring operations are carried on with 
 surprising rapidity. Scarcely half a minute is required for un- 
 screwing a joint, and a set of rods 650 feet long (200 m.) is drawn 
 up or lowered in 10 or 12 minutes. 
 
 For a hole 1000 feet (300 m.) deep, the four operations of 
 raising the chisel, lowering and raising the shell-pump, and 
 again lowering the rods and chisel, do not require more than 
 an hour. 
 
 Three men are required, of whom one is the master borer and 
 one the engineman. Their wages do not exceed 10 florins a day, 
 and if the wages of the smiths, who are constantly required, are 
 added, the total cost of wages per day will be from 15 to 16 
 florins. 
 
 The initial diameter of the hole varies from 9! inches (0*25 m.) 
 to 15! inches (0^40 m.) in loose ground, and the final diameter is 
 4 inches (o'io m.). The hole is lined with tubes throughout, 
 they are made of welded sheet-iron screwed together and perfectly 
 watertight. 
 
 The successive columns of tubes of the lower part of the hole 
 are placed one within the other. They are not withdrawn till the 
 hole is completed. The cost of the plant varies from 8000 to 
 10,000 florins, including a 12 to 15 h.-p. steam-engine, which, 
 with its boiler, comes to 3500 florins. To this must be added the 
 cost of the tubing, which, according to the diameter, varies from 
 3 to 10 or ii florins per metre. 
 
 The boring contractors ask from 15 to 25 florins per metre for 
 a boring estimated to be 1000 feet deep (300 metres), plus 50 per 
 cent, of the petroleum obtained in the first case, or 30 per cent. 
 in the latter. They leave the tubes necessary for preserving the 
 well, provided they are paid one-half of their value. Contracts are 
 also made for sinking wells at 50 florins per metre, without any 
 interest in the output. 
 
 As an example of the work, a well was bored 738 feet deep 
 
BORING. 137 
 
 (225 m.) at Wietrzno, by M. Suszycki, beginning with a diameter 
 of 15! inches (0-40 m.) and ending with 5f inches ('145 m.) in 90 
 days, of which 70 were occupied in actual boring. The average 
 progress was 10 feet 6 inches per day (3*20 m.),the maximum 32 
 feet (9-81 m.) per day. Several wells have been bored to a depth 
 of 1500 feet (over 450 metres) at Stoboda Runzwoska. Under 
 some exceptionally favourable circumstances a hole 475 feet 
 (145 m.) deep was bored in eight days with 140 hours of effective 
 work. 
 
 This system, therefore, seems suited to the conditions prevailing 
 in Galicia. The American method of boring with the rope, which 
 answers in Pennsylvania, where the beds are nearly horizontal, 
 did not succeed in Galicia, with the soft Tertiary rocks, which 
 often dip considerably. As regards the material for the rods, 
 wood is to be preferred to iron in Galicia. Wooden rods are 
 lighter and more easily manipulated than iron rods, besides which 
 they are more easily repaired, a matter of much importance in 
 districts far from foundries and engineering shops. 
 
 Driven Wells. Under the head of boring by percussion may 
 be classed the process of making driven wells, or Abyssinian tube- 
 wells, as they are often called in this country. A tube shod with 
 steel is rammed down by a heavy weight, raised by men with 
 ropes passing over a pulley, and then allowed to fall and strike 
 a stop clamped to the tube. The tube is perforated just above 
 the shoe, and when a water-bearing stratum of sand or gravel is 
 reached, water flows into it, and can be pumped up. This, how- 
 ever, is a special process, and can scarcely be considered as true 
 mining. 
 
 III. BORING BY PERCUSSION WITH ROPE. 
 
 American System. The use of the rope for boring is of very 
 ancient date in China, and the process has been brought to great 
 perfection in America for the purprse of obtaining petroleum and 
 natural gas. Within the last few years the American system 
 has been employed at Port Clarence, on the Tees, for obtaining 
 brine.* 
 
 The first operation consists in erecting the drilling rig, consist- 
 ing of the derrick, steam-engine, band-wheel, walking beam, bull- 
 wheel and sand-pump reel. 
 
 The derrick (Fig. 133) is a framework in the form of an acute 
 truncated pyramid, 72 feet high, 20 feet by 20 feet at the base, 
 and about 3 feet square at the top. It is ingeniously constructed 
 of 2 -inch plank, without any large or heavy pieces of timber, and 
 
 * C. Le Neve Foster, "Some Mining Notes in 1887," Trans. Min. Assoc. 
 and lmt. } Cvrmcall, vol. ii. Truro, 1888, p. 128. 
 
133 
 
 ORE AND STONE-MINING. 
 
 it serves to carry two pulleys. The reason of its height is to 
 enable the driller to raise the whole string of boring tools from 
 the hole without any disjointing. 
 
 The engine has a horizontal cylinder, 8 inches in diameter, 
 with a i2-inch stroke, and is reckoned to be of 15 horse-power. 
 
 FIG. 133. 
 
 By means of a belt, power is transmitted to a wooden pulley 
 (a) called the band-wheel ; this is provided with a crank (6), and 
 through a pitman (c) actuates one end of the walking beam (d), 
 26 feet long.* A smaller pulley bolted to the band- wheel enables 
 the bull-wheel (e) to be driven by an endless rope, and, by means 
 
 * The figure shows the pitman taken off from the crank pin. 
 
BORING. 
 
 139 
 
 of a lever, a friction pulley (/) can be brought against the band- 
 wheel so as to drive the sand reel. 
 
 These are the principal parts of the rig. In addition there are 
 wanted : 
 
 1. A set of drilling tools (h, i,j, k, I). 
 
 2. A sand-pump (m), or a bailer. 
 
 3. A rope (g) i J inch in diameter for lifting the tools. 
 
 4. A rope (g 1 ) J inch in diameter for working the bailer or 
 the sand-pump. 
 
 FIG. 134. FIG. 135. FIG. 136. FIG. 137. FIG. 138. FIG. 139. 
 
 The set of drilling tools consist of the following parts : 
 
 Rope socket 
 Sinker bar 
 Jars 
 
 Auger stem 
 Bit . 
 
 Diameter. 
 
 inches. 
 
 Fig. 134 (and 7>, Fig. 133) . 
 135 (and t ) . 3i 
 136 (andj ) . 
 137 (and k ) . 3^ 
 ij8& 139 (andZ, Fig. 133) 
 
 Length, 
 ieet. 
 
 3 
 
 12 
 
 6 
 
 3 2 
 
 Weight. 
 
 Ib.s 
 
 90 
 400 
 
 300 
 
 1050 
 
 140 
 
140 
 
 ORE AND STONE-MINING. 
 
 The jars are like two links of a chain, and their object is to 
 enable an upward blow to be struck if the bit sticks ; the force of 
 this upward blow is increased by the momentum of the sinker 
 bar. 
 
 The rope socket receives the end of the boring cable, any part 
 of which can be connected to the walking beam by a clamp at- 
 tache 1 to an adjustable link called the temper screw (Fig. 140). 
 
 FIG. 140. 
 
 FIG. 141, 
 
 FIG. 142. 
 
 6 
 
 The bailer is a wrought-iron cylinder, 18 or 20 feet long, with a 
 valve in the bottom, which opens as soon as its projecting stem 
 touches the ground. 
 
 The sand-pump (Fig. 141) is an iron cylinder, 5 feet or more long, 
 with a valve in the bottom and a piston. When it is lowered to 
 the bottom of the hole the piston descends, and when the piston 
 is raised, it sucks the mud and debris into the cylinder, and they 
 are retained by the valve. 
 
 When the hole has to pass through loose alluvial soil, a drive- 
 pipe (a a, Fig. 350) is rammed down before any true boring begins. 
 The drive-pipe is made of steel, J inch thick, and is 8| inches in 
 
BORING. 141 
 
 diameter internally. It is supplied in lo-feet lengths, arid these 
 are connected, like gas-pipes, by screwed sleeve couplings, 14 
 inches long. The first pipe is shod with a sharp steel shoe. 
 
 The drive-pipe, protected at the top by an iron cap, is rammed 
 down by a heavy wooden block (maul), like the ram or monkey of 
 a pile-driver, working between two vertical guides, and length 
 after length is added as it descends. The manner in which the 
 blow is given will be plain from the accompanying diagram (Fig. 
 142), in which the guides are omitted. The maul (a) hangs from a 
 rope or cable which passes over the crown pulley (b) at the top of 
 the derrick and round the shaft of the bull-wheel (c). Another 
 rope is attached to the crank of the band-wheel (d), and tied to 
 the first rope. As the crank revolves it pulls the cable and raises 
 the maul, and then letting the cable go back, causes the maul to 
 drop. 
 
 When the pipe has been rammed down until the shoe is driven 
 into hard ground, the earth inside has to be removed. A 
 swivel-head is attached to the rope in place of the block, and to it 
 are screwed the sinker bar, or the auger-stem, and a bit. This is 
 worked up and down like the maul, save that it is rotated ; water 
 is poured in, and soon the earth is knocked up into mud. The 
 sand-pump is then lowered and the mud brought up. These 
 operations are repeated, and when 60 feet have been cleared in 
 this way the regular boring can be commenced. 
 
 The proper cable is placed upon the bull-wheel shaft, one end 
 brought over the crown pulley and attached to the socket, and to 
 this, in succession, the sinker bar, jars, auger-stem, and bit. I will 
 now suppose the string of drilling tools to be hanging in the hole. 
 The temper screw (Fig. 140, and n Fig. 1 33) is clamped to the cable, 
 and its eye hung on to the hook at the end of the walking beam, 
 the cable is now lowered, and the string of tools hangs from the 
 walking beam. The engine is set in motion, and as the band- 
 wheel revolves, the crank turns and causes the walking beam to 
 move up and down, and the bit strikes a succession of blows at 
 the bottom of the hole. The driller rotates the tool by turning 
 the clamp round and round, this causes the slack of the cable to 
 coil around the part below the temper screw. After a time he 
 turns the other way, and the coils unwind ; this process is re- 
 peated over and over again. As the hole deepens, the screw 
 above the clamp is fed out, and when it can go no farther the 
 clamp is loosened, and shifted higher up after the screw has been 
 run back. 
 
 The gravel, sand, and mud made by the chipping motion of the 
 bit, are removed by the sand-pump lowered and raised by the 
 special rope on the sand-pump reel, driven by the friction pulley. 
 An examination of the small fragments drawn up in the sand- 
 pump, tells the driller what rocks he is passing through. The 
 two operations, drilling and clearing out, are repeated until the 
 
142 ORE AND STONE-MINING. 
 
 hole has reached the required depth. At Port Clarence the hole 
 has to be lined with a steel tube (Fig. 350, in which the size 
 of the tubes is greatly exaggerated), 6J inches in diameter in- 
 ternally ; for the first 150 feet from the bottom the steel is half 
 an inch thick, then five-sixteenths of an inch for 300 feet, and 
 the remainder quarter-inch thick. With the sleeve couplings 
 over them, they just pass down the drive-pipe. In the rock-salt 
 and in the 600 feet of water-bearing sandstone, the lining pipe 
 is perforated with holes one inch in diameter, and 1 2 inches apart 
 vertically.* 
 
 By the American system the cost of a brine well at Port 
 Clarence, 1000 feet deep, including the rig and a share of the 
 boiler, is ^1000, and it is drilled in three weeks. 
 
 Some wells bored by the diamond drill, on the other hand, cost 
 ^3000 each, and took three months to make. 
 
 The American system presents, therefore, very great advan- 
 tages, especially in the case where holes have to be numerous, and 
 where it is not certain how long a well will retain its productive- 
 ness. On the other hand, in making preliminary explorations of 
 the rocks of a new district, the diamond drill may fairly claim 
 the superiority, because it furnishes actual cores, showing the dip, 
 which give a better idea of the strata than pounded fragments. 
 
 Though to English eyes the American " rig " appears rather 
 rough, we cannot but admire its effectiveness, and also its suit- 
 ability in the case of petroleum and brine wells. The " rig " erected 
 for boring is utilised for pumping when the hole is completed, so 
 that there is no unnecessary expense in the plant. The various 
 parts of the " rig " are very simple in construction, and as timber 
 is largely used in place of metal, repairs can be done by the 
 master driller, without the aid of fitter or foundry.f 
 
 Mather and Platt's System. Another method of boring 
 with the rope is that which is employed by Messrs. Mather and 
 Platt.J Its peculiarities are a flat rope, and a special contrivance 
 for rotating the chisel. 
 
 Fig. 143 represents a side elevation of one of the boring 
 machines. 
 
 A A, flat hempen rope 4^ inches broad, by ^ inch thick ; B B, 
 boring head ; C, drum or reel for the rope, driven by the steam- 
 engine D ; E E, wooden or cast-iron frame ; F, guide pulley ; G, 
 flanged pulley carried in a fork on the top of the piston-rod of a 
 vertical single-acting steam-engine shown by the dotted lines. 
 
 * For the process of obtaining the salt see Chapter VI. 
 
 t Many of my figures and occasional explanations are borrowed from 
 the useful Illustrated Catalogue of the Oil Well Supply Co., Limited, of 
 Bradford and Oil City, Pennsylvania, who have furnished both the plant 
 and the drillers for the wells bored on the American system at Port 
 Clarence. 
 
 W. Mather, " On Weil-Boring and Pumping Machinery," Proc. Inst. 
 Mech. Eng., 1869, p. 278. 
 
BORING. 
 FIQ. 143. 
 
144 
 
 ORE AND STONE-MINING. 
 
 FIG. 144. 
 
 eolfuhct. 
 
BORING. 145 
 
 J is a clamp by which the rope A is fixed while boring is 
 going on. 
 
 Steam is admitted below the piston (Fig. 144) raising the 
 pulley G; at the end of the stroke, the exhaust valve is opened, 
 the steam escapes, and the piston, pulley, rope, and boring head all 
 drop. The exhaust port is so arranged as to leave a cushion of 
 steam which prevents the piston from striking the bottom of the 
 cylinder. The steam and exhaust valves are worked automatically 
 by tappets, M M, actuated by the piston-rod. The length of the 
 stroke can be varied from i to 8 feet by shifting these tappets. 
 The usual speed is 24 blows a minute. 
 
 The boring head (Fig. 145) forms a special feature of Mr. 
 Mather's invention. The chisels or cutters D are fixed by nuts 
 in the cast-iron block C ; E is a cylindrical block serving as a 
 guide, and F is a second or upper guide which assists in 
 effecting the rotation. On its circumference there are ribs 
 which catch in one direction ; the} are placed at an inclination, 
 like segments of a screw thread of very long pitch. Each 
 alternate plate has the projecting ribs inclined in the opposite 
 direction, so that one-half of the bars turn the rod round in 
 rising, and the other half turn it in the same direction during 
 the descent ; but they simply assist in producing the rotation 
 which is mainly secured by the contrivance represented above F. 
 Two cast-iron collars, G and H, are cottered to the top of 
 the bar B, and their deep ratchet-teeth are set exactly in line 
 with one another. J is a movable bush sliding upon the bar B, 
 and attached to the boring rope by the bow K and a short piece 
 of chain. 
 
 The bush J has ratchet-teeth on its upper and lower faces, but 
 the upper teeth are set half a tooth in advance of the lower 
 ones. During the ascent of the rope, the bush has the position 
 shown in the figure ; but when the tool strikes the blow, the 
 bush descends, and the centre of the inclined surface of each lower 
 tooth of J strikes the point of a tooth of G, and then slides down 
 on it, twisting J, and with it the flat rope, to the extent of half a 
 tooth. At the commencement of the lift the bush J receives 
 a further twist of half a tooth by coming against H. The flat 
 rope is thus twisted altogether to the extent of one tooth, and in 
 untwisting it turns the tool a like amount ; automatic rotation of 
 the cutters is thus secured. 
 
 P (Fig. 143) is the shell-pump, or sludger, and Q is an overhead 
 suspension bar by means of which it is brought over the litre 
 table R in the tank T. The screw S serves to raise the table R 
 until the pump rests upon it, and on knocking out a cotter in the 
 rod which supports the seating of the bottom valve, the sludge is 
 speedily discharged. 
 
 One man can attend to all the operations of raising and lower- 
 ing, changing the boring tool for the shell-pump or vice versd. 
 
i 4 6 
 
 FIG. 145. 
 
 ORE AND STONE-MINING. 
 W 
 
 Elevation/* 
 
 Q 
 
BOEING. 147 
 
 and regulating the boring. Two labourers are employed to 
 change the cutters and clear out the shell-pump. 
 
 Cores may be cut out as in other systems of boring, and 
 extracted, so as to show the nature and dip of the strata. As the 
 rope is flat, cores can he brought up without any twist. 
 
 The flat rope method is used by Messrs. Mather and Platt for 
 holes from 20 inches to 45 inches in diameter. In the case of 
 small holes from which no cores are required, they now adopt the 
 American system on account of its expeditiousness. 
 
 From what has been said it is very evident that a great diversity 
 of practice exists in making bore-holes, and the miner may have 
 some difficulty in making up his mind which system to adopt for 
 any given purpose. In the case of large undertakings, he usually 
 applies to some firm of engineers, who by long and constant expe- 
 rience in their art are able to guarantee success. 
 
 Surveying Bore-holes. It is often assumed by boring engi- 
 neers that the holes which they drill are perfectly vertical ; but 
 experience has shown that this is not always the case. It is, 
 therefore, important to have some means of measuring the devia- 
 tion of a bore-hole from the vertical, and surveying its exact course. 
 A useful instrument for this purpose is Macgeorge's clinograph.* 
 It consists in the main of two glass bulbs, the upper one carrying 
 a plummet, the lower one a magnetic needle ; both bulbs are 
 filled with gelatine. When hot the gelatine is liquid, and the 
 plummet and the needle are free to move ; when the gelatine is 
 cold both are set fast. The gelatine simply serves as a clamp 
 which will act of itself after a certain time. 
 
 The exact construction is explained by Eig. 146.^ The instru- 
 ment consists of a cylinder terminating in a short neck 
 and a bulb at the bottom. In this is a magnetic needle FIG. 146. 
 attached to a hollow pear-shaped glass float, which will 
 always stand upright upon its pivot and so enable the 
 needle to swing round without touching the sides. A 
 smaller glass cylinder, with a bulb at the top, is inserted 
 through an air-tight cork and a brass capsule at the upper 
 end of the large one. Its lower end passes into a cork, 
 which prevents the escape of the float of the needle. 
 The upper bulb contains a delicate plummet of glass, (^) 
 with diminutive hollow float at the top and a solid ball 
 at the bottom, which is prevented from dropping out by a delicate 
 grating. It is carefully adjusted to the specific gravity of the 
 solidifying fluid which fills the cylinders and bulbs, and is so 
 arranged that it will assume a vertical position whenever it is free 
 to move. 
 
 * "The Clinograph," Engineering, vol. xxxix. (1885), p. 260 "The 
 Diamond Drill Clinometer," Min. Jour., vol. liii. (1883), p. 1509. 
 t Brough, Mine Purveying, p. 276. 
 
i 4 8 OKE AND STONE-MINING. 
 
 In order to make use of these dip-recorders, or clinostats, as 
 Mr. Macgeorge calls them, six are placed in a bath of warm water, 
 which is heated nearly to boiling. In the meantime a brass 
 cylinder is also heated by filling it several times with boiling 
 water, and when the clinostats have been inserted one after the 
 other into it, it is lowered into the bore- hole and allowed to 
 remain there for two or three hours. By this time the gelatine 
 will have set ; the brass case is drawn up and the clinostats are 
 examined one by one in a special instrument designed by Mr. 
 Macgeorge. This has an arrangement for placing the clinostat 
 in exactly the same position which it occupied in the bore-hole, 
 and for enabling its angle of inclination and its magnetic bearing 
 to be measured very accurately. The mean of the six sets of 
 observations is then taken as representing the correct deviation. 
 
 If a bore-hole is approximately vertical, and the strata com- 
 paratively cool, the brass tube containing the clinostats may be 
 lowered with a wire rope ; but if the strata are hot or the bore- 
 hole somewhat flat, J-inch iron pipe is employed for inserting 
 the brass case. Care is taken to interpose a distance tube of 
 brass between the case and the pipes, to prevent their action on 
 the magnets. If the bore-hole is warm, cold water is forced down 
 the pipe so as to flow outside the case with the clinostats, and 
 congeal the gelatine. 
 
 If observations are made at regular intervals, say at every 100 
 feet, the path of the bore-hole can be traced with great accuracy. 
 
 The apparatus may also be used over a core extractor when it 
 is necessary to ascertain the direction and amount of the dip 
 of the strata. Macgeorge employs a brass tube set excentric- 
 ally, and provided with a bell-mouth below. This receives the 
 end of the core, and the excentricity of the tube causes pressure 
 on one side which makes the core break off. The core-extractor 
 contains an inner tube, slotted from end to end, which expands 
 as the core enters it and nips it tightly. 
 
 Mr. Macgeorge gives numerous instances of ascertained deflec- 
 tions of bore-holes. At Scotchman's United mine, Stawell, Vic- 
 toria (Figs. 147 and 148), a bore-hole 370 feet deep, put down with a 
 diamond drill, was found to have a deviation of 37 feet 3 inches 
 It is calculated that ^2311 would have been saved if the 
 path of the drill had been surveyed before the driving was com- 
 menced. At the Oriental Company's mine a bore-hole turned 
 out to be 60 feet 9 inches out of its proper course in a depth of 
 425 feet. Similar cases of deflection have been noted in bore-holes 
 made in Germany both by the diamond drill, and by the percussive 
 method. 
 
 The deviation from the vertical may likewise be recorded by 
 Nolten's* method, which depends upon the etching action of 
 
 * P. K., "The Deviation of Bore-holes," Colliery Guardian, vol. liii. 
 (1887), p. 775- 
 
BORING. 
 
 FIGS. 147 & 148. 
 
 149 
 
 Section 
 
 75 ft. 
 
 A, shaft ; B, supposed position of the bore-hole ; A B, level 
 driven out from A to strike the bore-hole ; C, actual position of 
 the bore-holes ; D, E, F, G, drivages made in search of the bore- 
 hole. The section shows that if the bore-hole had been continued 
 to a depth of 500 feet, the deviation would have amounted to 75 
 feet. 
 
150 ORE AND STONE-MINING. 
 
 hydrofluoric acid upon glass. A glass cylinder with a truly flat 
 bottom, and the sides at right angles to the base, is partly filled 
 with dilute hydrofluoric acid, put into a case, carefully lowered 
 into the hole, and allowed to remain there for half an hour. The 
 acid eats into the glass, which is then drawn up. The line of etching 
 records what was the horizontal plane when the cylinder was in 
 the bore-hole, and the angle between it and the flat bottom 
 measures the deviation from the vertical. 
 
 Trouve* has designed an electric lamp with a mirror set at an 
 angle of 45, which is lowered into the bore-hole and gives an 
 image of the strata. The observer at the surface examines this 
 image by mears of a telescope. 
 
 * Eng, Min. Jour., vol. 1. (1890), p. 483. 
 
CHAPTER IV. 
 BREAKING GKOUND 
 
 Hand tools: Shovel, crow-bar, pick, wedge, saw; tools for boring holes. 
 Excavating machinery. Transmission of powwby air, water, and 
 electricity. Diggers, dredges, rock-drills, groove-cutters,, tunnellers. 
 Explosives and blasting. Driving and sinking. Fijre-setting. 
 Excavating by water. 
 
 HAND TOOLS. The kinds of ground in which mlining 
 operations have to be carried on vary within the widest limits, 
 from loose quicksands to rocks which are so hard that the best 
 steel tools will scarcely touch them. 
 
 Shovel. Loose ground can.be removed witty the shovel. 
 Probably some of the first digging too^s were merely pointed sticks ; 
 indeed, the Burmese workman^ of to-ctay uses an iron-shod stake 
 for sinking oil-wells. Shovels ' vary v a good deal in shape and 
 make, according to the special purposes for which they are 
 employed, and also according to the fancies of the users. The 
 plate or blade is usually nlade of steel, and it is pointed in front, 
 so as to penetrate easily into the earth or Stone that has to be 
 moved. A wooden handle is attached to it; by a socket or two 
 long straps. The handle is often made of ash, and is usually 
 short, but in Cornwall and Devon a long one isj preferred. 
 
 In dealing with clay and sticky earth it is (advisable to have the 
 plate as smooth as possible ; the shovel vvith a hollow underneath 
 at the junction with the socket is objectionable for material of 
 this kind, because the cavity becomes choked, and the tool is then 
 less easily wielded. Even the projecting rivets sometimes used to 
 attach the socket to the plate cause a slight hindrance, which 
 means unnecessary waste of power. Shovels, like all other hand 
 tools, should be made as light as possible, consistent with strength, 
 in order to relieve the workmen from the unprofitable labour of 
 moving useless dead weight. 
 
 In the special case of peat, sharp spades are employed, which 
 cut through the woody fibres, and furnish lumps or sods of con- 
 venient form for drying and for subsequent \ise as fuel. 
 
 When it is desired to separate the larger stones from all finer 
 material, a fork with several prongs is a convenient tool. 
 
 Crowbar. This tool is an iron lever; it is used for pricing off 
 blocks of stone, and for shifting them after they , have been 
 detached. 
 
152 
 
 ORE AND STONE-MINING. 
 
 Pick. What is called fair, soft, or easy ground, such as clay, 
 shale, decomposed clay-slate, and chalk, requires the use of the 
 pick and the shovel ; the pick breaks up the ground, and the shovel 
 serves to shift it. The pick is a tool of variable form, according 
 
 FIG. 149. 
 
 FIG. 150. 
 
 If 
 
 to the material operated on. Thus there are the navvy's pick, the 
 poll-pick, with a point and a striking end (Fig. 149), and numerous 
 varieties of the double-pcinted pick (Fig. 150), the special tool of 
 the collier, but also largely used in ore and stone mining. The 
 
 FIG. 151. 
 
 FIG. 152. 
 
 blades of picks are made either of iron with steel tips, or else 
 entirely of steel. The latter is preferable, as it lasts so much 
 longer. The tip may be a point or a chisel edge. The blade is 
 usually eet at right angles to the hilt or handle j but at the under- 
 
BREAKING GROUND. 
 
 ground stone quarries at Bath and Weldon it is oblique, as shown 
 in Fig. 151. The object of this form is to enable the miner to cut 
 well into the corners of the deep horizontal groove required for 
 excavating the stone. This pick weighs 5 Ibs. 
 
 Blunted picks are sharpened by having the points heated in the 
 blacksmith's fire, hammered to the proper shape and tempered. 
 In order to save the trouble of carrying a large supply of tools, 
 the blade may be made separable from the hilt, and the miner 
 takes the blades only to the smithy when they are worn. Fig. 152 
 shows a pick of this description used at Mansfeld. 
 
 Two well-known forms of pick with separate blades are the 
 "Acme" and the "Universal" of the Hardy Patent Pick 
 Company. 
 
 The Acme (Fig. 153) is a pick used for " holing," or cutting a 
 groove in a soft rock, in which case it is advisable to have the tool 
 
 FIG. 153. 
 
 FIG. 154. 
 
 A 
 
 as narrow as possible, in order to avoid the unnecessary work which 
 a broad eye would occasion. The blade is made with a notch at 
 the top, and a wedge makes it fast to the head ; blades vary from 
 i J to 3 Ibs. in weight. 
 
 The Universal (Fig. 154) has the large end of the shaft or handle 
 fitted with a cast steel or malleable iron socket; the small end is put 
 through the eye of the blade, which becomes firmly fixed, because 
 the socket and eye are carefully made to gauge. By striking the 
 small end of the handle on the ground the blade is loosened and 
 removed. Blades of various shapes may be fixed upon the same 
 handle, which is sometimes an advantage in remote districts. 
 
 The handles (" hilts " or " shafts ") are commonly made of ash 
 or hickory. In Australia and New Zealand the wattle furnishes 
 a light, tough, elastic, and durable wood for the handles of picks 
 
154 ORE AND STONE-MINING. 
 
 and other tools. One of the best descriptions is the Golden Green 
 Wattle (Acacia decurrens, var. mollis). 
 
 Wedge. When the ground, though harder, is nevertheless 
 " jointy," or traversed by many natural fissures, the wedge comes 
 into play. The Cornish tool known as a gad is a pointed wedge 
 (Fig. 155). The so-called "pick and gad " work con- 
 sists in breaking away the easy ground with the point 
 of the pick, wedging off pieces with the gad, driven in 
 by a sledge or the poll of the pick, or prising them off 
 with the pick after they have been loosened by the gad. 
 The Saxon gad is held on a little handle, and is 
 struck with a hammer. It is used like the Cornish 
 gad for wedging off pieces of jointy ground, and in 
 former days even hard rocks were excavated by its 
 aid. The process consisted in chipping out a series of parallel 
 grooves, and then chipping away the ridges left between them. 
 As a method of driving levels or sinking shafts, this process is 
 naturally obsolete ; but it is useful on a small scale for cutting 
 recesses (hitches) for fixing timber, for dressing the sides of levels 
 or shafts before putting in dams, and for doing work in places 
 where blasting might injure pumps or other machinery. 
 
 Saws. Freestone is sometimes excavated by sawing. The 
 saws are 6 or 8 feet long, and i foot wide. The wooden handle 
 
 can be fixed so that no part 
 
 FIG. 156. projects above the saw when 
 
 the tool is used close to the 
 roof (Fig. 156). 
 
 Tools used for Boring 
 and Blasting. We now come 
 to hard ground; and in this 
 class we have a large propor- 
 tion of the rocks met with by the miner, such as slate of various 
 kinds, hard grit and sandstone, limestone, the metamorphic schists, 
 granite, and the contents of many mineral veins. 
 
 Rocks of this kind are attacked by boring and blasting. The 
 tools employed are the auger, jumper, or borer (drill), hammer or 
 sledge (mallet, Cornwall), scraper and charger, tamping bar or 
 stemmer, pricker or needle, claying bar and crowbar. 
 
 Augers. At English gypsum mines a tool resembling the car- 
 penter's shell-auger is regularly used for boring holes for blasting. 
 It is worked by a cross handle, and makes a hole ij inch in 
 diameter. Boring is done in the bituminous limestone of Seyssel 
 by screw-augers in a similar manner. 
 
 Elliott Drill. Screw-augers mounted upon stands are common. 
 Fig. 157 represents the Elliott drill, which consists of an auger 
 inserted into a socket upon a feed-screw c, which works upon a 
 worm-wheel a, held fast in a ring, when the screw clamp b is 
 tightened. On moving a ratchet brace backwards and forwards, 
 
 jf 
 
BREAKING GROUND. 
 
 155 
 
 c is turned round, carrying the auger with it, and when the worm- 
 wheel is tight, it advances slowly at the same time. If a very 
 hard piece of rock prevents the penetration of the auger, the 
 worm-wheel slips in the ring, and, by suitably arranging the 
 tightness of the clamp 6, the machine can be made to accommo- 
 date its advance to the nature of the rock. 
 
 The drill itself is made of a bar of twisted steel, which clears 
 itself of the debris to a certain extent ; when it has penetrated as 
 far as it will go, the clamp is loosened, enabling the feed- 
 Fcrew to be drawn back rapidly without rotating at all. A longer 
 drill is put in, and work continued. 
 
 The light frame or standard is made in two halves, and by 
 shifting a pin its length can be altered to suit the height of the 
 
 FIG. 157. 
 
 FIG. 158. 
 
 working place, whilst the final tightening is done by a screw at 
 the bottom. 
 
 Ratchet Drill. Where even more simplicity is required, a self- 
 feeding ratchet drill can be employed, with a piece of timber set 
 up in the working place as an abutment. An auger is inserted 
 into a socket upon a feed-screw a (Fig. 158), working in the nut b, 
 attached to a long sheath. When the ratchet handle c is worked, a 
 revolves and at the same time advances from the feed-nut, carrying 
 the auger with it. The sheath is prevented from turning by 
 putting the eye of a pin over one of the projecting pegs at the rear 
 end, and allowing the pin to be brought up by the first twists against 
 the piece of timber. For enabling the feed-screw, after it has 
 advanced to its full length, to be quickly returned into the sheath, 
 the Hardy Patent Pick Company sometimes use Stayner's Patent 
 
ORE AND STONE-MINING. 
 
 DlAME 
 
 J 
 
 H 
 
 / t=a v. . LJ - 
 
 FIG. 159, FIG. 161, FIG. 160. FIG. 162. FIG. 163. 
 
BREAKING GROUND. 157 
 
 Split Nut, instead of an ordinary nut ; when the split nut is 
 loosened, the feed-screw can be moved back without loss of time 
 in turning. 
 
 These augers worked by hand will do good work in moderately 
 hard ground, such as tough shale, slate, and even sandstone. 
 
 Jumper. The simplest tool for boring holes by percussive 
 action is the jumper, a bar of iron tipped with steel, forged into 
 a chisel-shaped edge. It is struck against the rock, and turned 
 a little at each blow, and in this way. chips out a cylindrical 
 hole. 
 
 Fig. 159 represents the jumper used in "the lead bearing sand- 
 stone at Mechernich, made of a bar of iron J inch in diameter, 
 and 7 to 10 feet in length. As the rock is soft, the cutting edge 
 can be made wide and sharp. The exact angle of the actual 
 cutting edge of a jumper which I measured was 42 ; the final 
 sharpening is done with a file. At the open workings for iron- 
 stone in Northamptonshire, the edge comes to a point in the 
 middle (Fig. 160). 
 
 The jumper used in the Festiniog slate mines (Fig. 161) has a 
 swelling in the middle, and both ends are sharpened ; the short 
 end serves for beginning a hole, the large one for completing it. 
 The ordinary sharpening is done by heating the end red-hot, and 
 filing it to the desired form while the jumper is held in a vice. It 
 is allowed to cool gradually, and then is heated again in the forge, 
 hardened in water and tempered. 
 
 The jumper for boring holes at any angle in the rock-salt of 
 Cheshire has a swelling in the middle, and tapers gradually to 
 each end. 
 
 The jumper of the Cleveland ironstone miner (Fig. 162) has the 
 swelling at one end, and will bore holes at any angle. Like the 
 Festiniog tool, it is sharpened by being hammered into shape, and 
 finally filed when hot. 
 
 Borers. When the rocks are harder, and also in situations 
 where a jumper cannot be wielded, the miner must have recourse 
 to the borer or drill, which is simply a steel chisel (Fig. 163). 
 
 The steel is brought to the mine in the form of round or 
 octagonal bars, and is cut up by the mine- smith into pieces of 
 the required length; one end is forged into a chisel-shaped 
 edge, the exact shape and degree of sharpness varying according 
 to the hardness of the rock. For hand-drilling the steel is usually 
 | inch to i inch in diameter, but f inch or even J inch steel is 
 sometimes used. The old plan of making the drill of iron, and 
 welding on a piece of steel for the cutting edge (bit), is almost 
 extinct in this country. 
 
 The shape of the bit of the hand drills used at Minera mine, 
 North Wales, is shown in Figs. 164 and 165, the angle of the 
 edge being 84 The drills used with the compressed air machines 
 at Minera are rather blunter than a right angle. At a limestone 
 
153 
 
 ORE AND STONE-MINING. 
 
 FIGS. 164 & 165. 
 
 quarry, near the mine, the drills have two cutting edges arranged 
 in step-fashion. 
 
 Drills for hard rocks are sharpened entirely at the forge; the 
 cutting edge is hammered into the desired shape on the anvil 
 
 while red-hot, and then hard- 
 ened to suit the particular 
 requirements of the user. In 
 many cases the desired temper 
 is obtained by plunging the 
 tool when at a blood-colour 
 into cold water, and allowing 
 it to remain there ; but for 
 soft rock the tool will work 
 efficiently after the hardness 
 has been reduced by anneal- 
 ing. In the case of slate the 
 smith heats the end of the 
 
 jumper to blood-colour, and just dips the edge into water for a 
 few seconds. He now watches its colour as it cools down, and 
 stops the annealing or tempering action by plunging the tool into 
 cold water when a certain shade of blue has been reached. Some 
 smiths rub the edge of the tool upon a piece of board with a little 
 sand, in order to be able to follow the changes of hue with pre- 
 cision. 
 
 Before the introduction of machines, as many as fifty drills 
 were sometimes blunted in boring a hole 2 feet deep by hand at 
 an iron pyrites mine in Carnarvonshire. This is an exceptional 
 case, but nevertheless the importance of having a good smith at a 
 mine where much sharpening has to be done cannot be over- 
 estimated. 
 
 A tool called a "bull "is employed in boring holes in tough 
 haematite and tough clay in some districts. It is a bar pointed at 
 one end and provided with an eye at the other. It is driven into 
 the ore with a sledge, and by putting another bar through the 
 eye it can be withdrawn without difficulty. There is practically 
 no difference between it and the claying bar (Fig. 172). 
 
 Hammers. The hole is bored by striking the drill with a 
 hammer or sledge, and turning it after each blow. Boring is 
 said to be single-handed if the miner holds the drill in one hand 
 and wields the hammer with the other ; whilst it is called double- 
 handed when one man strikes and another turns. Sometimes 
 there are two men to strike, one after the other, whilst a third 
 man turns the drill. 
 
 In starting a hole a short drill is chosen, and longer ones are 
 taken as the hole is deepened ; the smith is careful to make 
 the cutting edges (bits) diminish slightly in width as the borers 
 increase in length, because the hole gradually decreases in 
 diameter as the tool wears. The bore-hole is therefore not a true 
 
BREAKING GROUND. 
 
 159 
 
 FIG. 1 66. 
 
 cylinder, but a frustum of a very elongated cone. It may even 
 happen that, owing to the manner in which the miner has turned 
 his borer, the section of the hole forms a triangle and not a circle. 
 The deep holes bored for quarrying granite invariably become 
 triangular after a small depth has been reached ; but 
 the sides are straighter and the corners less sharp 
 than shown in Fig. 166, which represents a shape 
 sometimes seen in slate. 
 
 Boring hammers and sledges are almost universally 
 made of steel ; but until comparatively lately iron 
 hammers with a steel face or pane were common, 
 and even in some districts the head of the hammer was made 
 entirely of iron, which was worn into a deep hole by the end of 
 the hard steel drill. 
 
 The hammers for single handed boring vary in weight from 
 2 to 6 or 7 Ibs. The hammers used by the Festiniog miners and 
 quarrymen weigh from 5^ to 7 Ibs (Fig. 167). The handle is 10 to 
 1 2 inches long. In some districts the head is curved slightly, se 
 
 FIG. 167. 
 
 as to follow the circle in which it is swung. A good miner should 
 be able to wield the hammer with either hand, because he may 
 have to put in a hole close to either side of a level or stope ; he 
 should also be able to strike upwards, because occasions arise 
 where a hole bored in this manner will be far more advantageous 
 for removing rock than one bored downwards. 
 
 The double-handed boring hammer or sledge (mallet, Cornwall) 
 weighs from 6 to 10 Ibs. or more, and the handle is 2 feet or more 
 long (Fig. 1 68). If swung round by good hands, it strikes a very 
 powerful blow. 
 
 In a rock-boring competition in Cornwall* a few years ago, thre 
 men from Tincroft mine, two striking and one turning, bored a 
 hole 13 inches deep in hard granite in 6 minutes 43 seconds, 
 
 * Tlw West Briton, Aug. 9, 1888. 
 
i6o 
 
 ORE AND STONE-MINING. 
 
 FIG. 1 68. 
 
 making 91 blows per minute; three men from Dolcoath bored 
 12 J inches in 7 minutes 18 seconds, making 130 blows per minute, 
 whilst a like number from Carn Brea bored 1 2f inches in 8 minutes 
 with 117 blows per minute. The Tincroft men 
 slung the sledge round, the others did not. The 
 drills used were made of steel, i inch in diameter ; 
 but there was no restriction as to the size or shape 
 of the bit. Of course these results are simply use- 
 ful as showing what can be done under very favour- 
 able circumstances, and for a very short time. 
 
 If the hole is directed downwards, the miner 
 throws in a little water and bores the rock wet. A 
 ring of rope or leather put round the drill prevents 
 the water from splashing him. The water serves 
 three purposes: it renders the boring easier by 
 holding the fine particles in suspension instead of 
 their lying at the bottom of the hole ; it keeps the 
 tool cool, which makes it last longer, and it prevents 
 dust, which would otherwise be breathed by the 
 miner and tend to cause lung disease. In places 
 where miners are paid by the depth bored, a higher 
 price per inch is sometimes given for holes bored dry than for 
 those bored wet. The depth bored varies with the rock, and the 
 nature of the excavation ; but in driving levels in the ordinary 
 way by hand, the depth is commonly from 18 inches to 3 feet. 
 
 Scraper. From time to time the miner draws out the sludge 
 with a " swab-stick," or the dust with a scraper. The former is 
 a wooden stick with the fibres at one end frayed into a sort cf 
 mop ; the latter is a little disc at the end of a metal rod. For 
 removing small bits of stone a rude syringe, called a " gun," is 
 occasionally employed ; it is a piece of gas-pipe, or an old gun- 
 barrel, fitted with an iron piston made tight by hemp. It also 
 serves for flushing out " uppers." 
 
 The accessory tools required subsequently for charging the hole, 
 are the tamping-bar or stemmer, pricker or needle, charging-spoon, 
 cartridge stick, and claying-bar. 
 
 Tamping-bar. The tamping-bar or stemmer is a rod of wood, 
 iron, copper or bronze, or iron shod with copper, and it is used 
 
 FIG. 169. 
 
 for ramming in clay, pounded slate, sand, or the dust from the 
 bore-hole or other suitable material upon the explosive, and so 
 causing a resistance sufficient to make the gases generated by the 
 blast rend the rock in the manner required. 
 
 The tamping-bar (Fig. 169) is sometimes a plain metal rod, with 
 a little swelling at the striking end, but often a groove is left to 
 
BREAKING GROUND. 161 
 
 lessen the chance of injuring the fuse ; the use of this groove is 
 more apparent when the pricker is employed. 
 
 Pricker. The pricker or needle (Fig. 170) is a slender tapering 
 rod of copper or bronze with a ring at the large end. It is used 
 
 FIG. 170. 
 
 * 4.'. 6" \ 
 
 for maintaining a hole in the tamping through which the charge 
 can be fired by a squib, rush or straw. 
 
 Charging -spoon. The charging-spoon is a hollow half- 
 cylinder of copper or zinc, at the end of a copper or wooden rod, 
 which is used for introducing loose gunpowder into holes which 
 
 FIG. 171. 
 
 are more or less horizontal. The scraper and spoon are often 
 combined (Fig. 171). In the Festiniog slate mines, a copper tube 
 5 feet long, with an expanded mouth, is sometimes used for putting 
 a second charge of gunpowder to the bottom of a hole which has 
 simply produced a rent, without severing the block of slate from 
 the working face. 
 
 Cinder the Coal Mines Regulation Act of 1887, prickers, 
 scrapers, chargers and stemmers must not be made of iron or steel ; 
 the Metalliferous Mines Act, 1872, likewise prohibits iron or steel 
 prickers, but allows iron stemmers, provided they are not used in 
 the early part of the operation of tamping. 
 
 Cartridge Stick. The cartridge stick is a smooth cylinder of 
 wood, around which paper is bent in order to make cases for 
 holding gunpowder or the tamping material, when these have to 
 be inserted into holes which have a very decided upward inclina- 
 tion. The paper is fastened by a little pitch softened in the 
 miner's candle. One advantage of cartridges for all holes is the 
 absence of danger from grains sticking to the sides; when powder 
 is put in loose, a premature explosion may happen from such 
 grains being ignited during the process of tamping and conveying 
 fixe to the charge. 
 
 FIG. 172. 
 
 Claying-bar. The claying-bar (Fig. 172) is a smooth rod of 
 steel a, expanded at. one end into an eye c. It was used formerly 
 for lining wet holes with clay, and so rendering them temporarily 
 
162 
 
 ORE AND STONE-MINING. 
 
 watertight, and fit for holding a charge of gunpowder. Lumps 
 of clay were put into the wet hole, and the claying iron was driven 
 in by blows on the head 6, forcing the clay into every fissure. By 
 putting an iron bar through the eye, it could easily be twisted and 
 withdrawn. Nowadays wet holes are almost invariably charged 
 with some nitre-glycerine explosive, and the claying-bar is rarely 
 required. 
 
 Rending Holes. Where a stone can be made to rend along 
 certain lines, cost may be saved by shaping the holes so as to start 
 
 FIG. 173. 
 
 FIG. 174. 
 
 FIG. 175. 
 
 the rifts in the desired directions. This is the principle of the 
 Knox* system of blasting employed at the sandstone quarries of 
 Portland, Conn., and elsewhere in the United States. A round 
 hole (Fig. 173) is drilled by hand or by machine, and then two 
 V-shaped grooves (Fig. 174) are cut down with a reamer (Fig. 
 175) in the line of the proposed rift. The tool I 
 found in use at Berua, Ohio, is slightly different 
 in shape, but acts in the same way. The hole, 
 when fired, produces a crack or rift in the direction 
 AB. Several holes may be bored in a line if neces- 
 sary, and fired simultaneously by electricity. The 
 Githen system, lately adopted by the Ingersoll-Ser- 
 geant Rock Drill Company, goes a step further ; for 
 machine drills are now being made which will bore 
 holes with an elongated section in one operation. 
 
 USE OP MACHINERY FOR, BREAKING 
 GROUND. One of the greatest improvements in 
 the art of mining during the last quarter of a cen- 
 tury has been the introduction of machines instead 
 of human power, for performing some of the most 
 laborious work in mining ; the mine-owner is able 
 to have work done more quickly and more cheaply, 
 and the working miner is relieved from severe toil 
 under unfavourable conditions. 
 
 The power may be generated on the spot, or can 
 be transmitted underground from prime movers 
 on the surface. 
 
 As means of generating power on the spot we may turn to 
 steam, water, or petroleum. 
 
 * Saunders, " Dimension Stone Quarrying. The Blasting Process.'' 
 Trans. Amer. 8oc. C.E., vol. xxv. (Nov. 1891), p. 504. 
 
;' BREAKING GROUND. 163 
 
 . Though boring machines in open quarries are often worked by 
 steam supplied from small boilers which can be moved about on 
 trucks, appliances of this kind are out of the question in most 
 underground workings, on account of the nature and small size of 
 the excavations, the inconvenience and danger caused by the 
 fire and heat, and the trouble of getting rid of the products of 
 combustion and of the exhaust. 
 
 Power can be obtained by bringing down water in pipes from 
 the surface, or from overlying strata in which it is dammed back 
 by a watertight lining (tubbing). This method has the advantage 
 of requiring no plant except the pipes, but there is the disadvan- 
 tage that the water must be pumped up again, unless the workings 
 are drained by an adit level. However, it may be cheaper and 
 easier to work the ordinary pumps a little faster than to erect 
 special air-compressing machines. Hydraulic power has the dis- 
 advantage, compared with pneumatic power, of not ventilating the 
 workings ; and in certain cases, when the floor is soft and clayey, 
 or composed of rock-salt or saliferous marls, the flow of water 
 would be objectionable. 
 
 The petroleum engine, an invention of modern times, is already 
 in use in mines, not only for breaking ground, but also for 
 pumping and hauling. It resembles a gas engine, save that 
 the explosive mixture is produced by heating a spray of petroleum 
 and air. It is found that the consumption of ordinary mineral 
 oil is decidedly less than i pint per brake horse-power per hour ; 
 reckoning the oil at 5 Jd. per gallon, the cost of a brake horse-power 
 per hour is less than Jd. The danger which these machines would 
 introduce into some mines is self-evident, and they nre not fitted for 
 use in breaking ground unless the workings are of a nature to allow 
 them to be moved about on rails. In the particular case of the thick 
 bed of Cleveland ironstone, they are employed with advantage. 
 
 TRANSMISSION OP POWER. The generation power 
 in the working place itself is exceptional, and the problem 
 usually to be solved is how best to transmit the power of steam 
 or hydraulic engines at the surface to the machines employed 
 underground. 
 
 Power is transmitted in mines in six different ways : 
 
 (1} By rods. (4) By air. 
 
 (2) By ropes. (5) By water. 
 
 (3) By steam. (6) By electricity. 
 
 Rods of wood or iron are chiefly employed in the case of pump- 
 ing machinery, and ropes in the case of hauling machinery, both 
 of which will be referred to in later chapters. 
 
 Steam generated by boilers above ground, and conveyed by 
 pipes under ground, does not commend itself for driving machines 
 at the working faces in mines. The drawbacks to its employment 
 are the loss of pressure through condensation in the pipes, the 
 
1 64 ORE AND STONE-MINING. 
 
 inconvenience and danger of leaks, the discomfort of the heat, 
 and the trouble of the exhaust steam. The first defect may be 
 considerably lessened by carefully jacketing the pipes. 
 
 There remain, then : air, water, and electricity, all of which are 
 in actual practical use at the present time. 
 
 Air. The transmission of power by compressed air has the 
 immense advantage that the exhaust escaping from the machines 
 benefits the ventilation of the mine ; there is, on the other hand, 
 the drawback of considerable loss of power. 
 
 Mr. Sturgeon* estimates that where the air is used without 
 re- heating and without expansion, the engine worked by the air 
 will develop only 31-9 per cent, of the power of the engine 
 used in compressing it. In some actual cases where the efficiency 
 has been tested practically, the loss of power has been far 
 greater than even the 68* i per cent, calculated by Mr. Sturgeon. 
 Professor Kennedy f found by experiments upon the transmission 
 of power by compressed air in Paris (Popp's system), that the 
 efficiency with cold air was 39 per cent. ; in other words, it re- 
 quired 2*6 indicated horse-power at the central station to produce i 
 indicated horse- power at the motor. 
 
 Air compressors are simply force-pumps, but the ingenuity of 
 inventors has been largely exercised in order to overcome the 
 shortcomings of the pneumatic mode of transmitting power. 
 Attempts have been made especially to combat the loss of 
 efficiency caused by the clearance spaces and by the heating of 
 air when compressed. The effects of these two drawbacks are 
 readily understood. Suppose the piston of an air-compressing 
 cylinder to have reached one end of its course, the air in the 
 clearance space on the compressing side is at the pressure pro- 
 duced by the machine; when the piston reverses its stroke, 
 this air expands, and the admission valves will not open until its 
 pressure has been reduced to a point just below that of the 
 atmosphere. The first part of the stroke is therefore ineffective, 
 and the greater the clearance, the greater is the difference between 
 the theoretical volume of air, calculated from the diameter and 
 stroke of the piston, and that actually delivered into the reservoir. 
 However, from a mechanical point of view, the power required to 
 compress the air in the clearance space is nearly all returned by 
 its expansion when the piston changes its direction. 
 
 The loss of efficiency due to heating is felt in two ways : the 
 power expended in producing heat is wasted, and the hotter the 
 air the smaller is the actual quantity delivered by each stroke 
 of the compressor. This latter evil may be lessened by various 
 methods of cooling, and we are thus led to the following classifi- 
 cation of air-compressors : 
 
 * '* The Birmingham Compressed-air Power Scheme." Paper read before 
 the British Association. Birmingham, 1886, p. 15. 
 f Hep. Brit. Assoc., 1889, p. 456. 
 
BREAKING GROUND. 165 
 
 I. Water-column compressors. 
 II. Injection compressors. 
 III. Dry compressors. 
 
 I. Water-column Compressors. The machines of this class have 
 the advantage of using a cold surface for compressing, which 
 absorbs the heat of the air with which it is in contact. They also 
 get rid of the drawback of clearance or dead spaces, for the water 
 can be made to expel all the air at each stroke, and, lastly, there 
 can be no escape of o air past the piston. An early form was that 
 of Sommeiller,* and Angstrom's t compressor, used with success in 
 Sweden in the infancy of rock-drills, was one of the same type. 
 It consisted of two vertical barrels, connected at the bottom, and 
 each provided at the top with an inlet and an outlet valve. The 
 barrels were filled with water in such a manner that the up and 
 down motion of the piston forced the air out or drew it in, 
 according as the column was being made to rise or sink. The 
 piston made only four strokes a minute. 
 
 Hanarte's compressor (Fig. 176), now employed in France and 
 Belgium, has a piston B travelling horizontally like that of Som- 
 
 \ 
 
 meiller, but the upright portions A A, instead of being cylinders, 
 are paraboloids ; C C are the inlet valves, and D is one of the 
 outlet valves. This arrangement allows a greater number of 
 strokes per minute, because the speed of the water diminishes 
 as it rises, although the speed of the piston may be uniform, and 
 also because the area of the cooling surface increases in proportion 
 to the amount of heating generated by compression. A Hanarte 
 compressor erected at BlanzyJ in 1887 could not be driven at 
 more than 24 strokes a minute, and gave some trouble from 
 frequent repairs of the valves. Like other machines of this class, 
 it also had the defect of dashing a little water through the valves, 
 but on the whole it worked satisfactorily. 
 
 * Figured in Hughes' Text-Book of Coal Mining, p. 49. 
 
 t C. Le Neve Foster, " An Account of Bergstrom's Boring Machine, now 
 in use at the Persberg Mines, Sweden," Trans. Min. Assoc. Cornwall and 
 JJevon, 1867, p. 7. 
 
 I Mathet, L'air comprime aux mines de Llanzy. Saint Etienne, 1889, 
 pp. 15, 24. 
 
i66 
 
 ORE AND STONE-MINING. 
 
 II. Injection Compressors. In the injection compressors, water 
 is being constantly introduced in order to absorb heat from the 
 air, and at the same time it has the effect of partly or completely 
 filling up the clearance spaces, and of so still further contributing 
 to the effective working of the machine. It is either drawn in 
 through the admission valves, or, better, it is forced in as a spray. 
 In a finely divided state it will naturally act more efficaciously in 
 a short time, which is of the utmost importance with a quick- 
 working compressor. 
 
 Figure 177 represents one form of a Dubois and Frangois 
 injection compressor. A is the piston, P ^ - + u - *-~ -'- 1 - 4 - 
 
 FIG. 177. 
 
 are the two inlet 
 
 valves, and C C the two outlet valves. D D are pipes bringing in 
 water, which is injected as a spray into the cylinder, 
 
 It has been found in many cases that, though the spray 
 undoubtedly has a cooling effect, its use is coupled with the dis- 
 advantage that the piston and cylinder wear rapidly ; therefore 
 many engineers are of the opinion that it is better to put up with 
 a slight imperfection in the cooling, than to have a loss of 
 efficiency through a badly fitting piston. 
 
 III. Dry Compressors. Very many compressors are worked 
 dry, and the air is cooled by its contact with the surface of the 
 sides or ends of the cylinder, which are prevented from getting 
 hot by the circulation of cold water outside them. 
 
 Among the dry compressors may be mentioned that of Burck- 
 hardt and Weiss, of Bale, which was in favour at Blanzy* in 1889, 
 on account of certain advantages which it possesses over other 
 forms of machines, especially the great speed at which it can be 
 worked, the delivery of a dry air, and the suppression of the evil 
 caused by clearance. The benefit of a rapid stroke is that a small 
 machine, costing less money, occupying less space, more easily 
 
 * Mathet, op. cit. p. 24. Further details concerning this compressor 
 will be found in a pamphlet issued by the firm for the Paris Exhibition, 
 1889, and in the Revue Universelle des Mines et de la Metalluryie, 1889, 
 p. 279 ; 1890, p. 202. 
 
BREAKING GROUND. 
 
 167 
 
 transported, and more cheaply erected, does as much work as a 
 large machine driven slowly. Great speed of working is rendered 
 possible by effecting the distribution of the air by a slide-valve 
 worked mechanically, instead of having valves which open and shut 
 automatically, owing to the difference of pressure on their faces ; 
 and the injurious effect of clearance is greatly reduced by having 
 a small passage in the slide-valve, which puts both sides of the 
 piston into communication with each other at the end of every 
 stroke. Consequently, when the direction of the piston is reversed, 
 it at once begins to draw in air, instead of having the first part of 
 its course ineffective, as is the case with many compressors. It 
 must be pointed out, however, that the increase in the volumetric 
 delivery of air effected in this manner is carried out at the expense 
 of a certain amount of power. As already explained, the power 
 required for compressing the air in the clearance space is not 
 entirely thrown away in the ordinary machines ; a part, at all 
 events, is stored up for a moment, and helps the piston in its 
 course as soon as the stroke is reversed. In the Burckhardt and 
 Weiss compressor this power is wasted. The cooling arrangements 
 of this machine have been very carefully studied. A current of 
 cold water is made to circulate not only around the cylinder as 
 usual, but also at both ends, a matter of importance, because it is 
 precisely at the ends that the heating is greatest, and that there 
 is the greatest need of refrigeration. The piston and the slide- 
 valve are kept greased with oil deli vt red drop by drop from one of 
 Weiss's sight-feed lubricators. 
 
 FIG. 178. 
 
 The long experience of the Ingersoll-Sergeant Rock Drill 
 Company* has led them to adopt the compressor shown in Fig. 
 178. It has a double-acting air cylinder, with an inlet valve a on 
 each face of the piston. Fig. 179 is a perspective view of one of 
 
 * Caunders, Compressed Air Production. New York, 1891, p. 22. 
 
168 
 
 ORE AND STONE-MINING. 
 
 FIG. 179. 
 
 these ring-shaped valves. The compressed air leaves the cylinder 
 by the valves b b (Fig. 178); c c are grooves turned in the ends 
 of the cylinder which receive the projecting parts of the valves on 
 the piston, and so enable the clearance to be reduced to a minimum. 
 The cylinder is kept cool by the circulation 
 of water through the spaces d and e, and, 
 save where there is the outlet valve, the 
 whole of each end participates in the re- 
 frigeration by means of the water-jackets, 
 d d. The action of the compressor is simple. 
 The air enters the piston by the tail pipe 
 which is attached to it, and, according to the 
 direction of the stroke, opens one or other of 
 
 the ring- valves leading into the cylinder. When the direction of 
 the stroke is reversed, this air is compressed, opens one of the 
 valves, 6, and passes out at/. 
 
 For very high pressures it may be advisable to use compound 
 machines ; that is to say, machines in which the compression is 
 effected in two cylinders instead of one. The air is first partly 
 compressed in a large cylinder, and, passing into a smaller one, is 
 brought to the required high pressure. For the pressures ordinarily 
 used in mining, say 50 to 70 Ibs. per square inch, compound com- 
 pressors are not, as a rule, thought necessary. 
 
 The usual type of air compressor used at mines is illustrated by 
 the diagram, Fig. 180. A A are the two steam cylinders, B the 
 fly-wheel, and C C the two air cylinders. It is sometimes thought 
 
 FIG. 1 80. 
 
 fe 
 
 flilllihiili 
 
 1 .ililllHimillllllllll 
 
 more economical to make the engine compound, and in that case 
 one of the two cylinders takes the steam at high pressure and the 
 other at low pressure, after it has somewhat expanded. 
 
 A point often neglected is the state of the air supplied to the 
 compressor. The I nger soil -Sergeant Company are quite right in 
 insisting that the air should be taken where it is as dry, cold, and 
 free from dust as possible. 
 
 In order to secure uniformity of pressure and get rid of water 
 and impurities, the air is led from the compressor into a reservoir, 
 often an egg- ended boiler ; it should be provided with a safety- 
 valve, a pressure gauge, and also with a cock for letting off the 
 
BREAKING GROUND. 
 
 169 
 
 water which collects gradually, especially in the case of wet com- 
 pressors. Sometimes a gauge is added in order to indicate the 
 height to which the water rises. 
 
 Several underground reservoirs have been constructed at Mans- 
 feld.* One is a chamber 10 m. long, 1*5 m. wide, and 1*5 m. high 
 at the mouth, and then enlarged to 3 m. wide by 2*2 m. high. 
 All loose stone was carefully removed, and the walls were plastered 
 over, first with cement, and then with a mortar made of equal 
 parts of cement and sand. A brick dam was erected in the con- 
 tracted mouth of the bottle-like chamber, and in order to make it 
 thoroughly air-tight, a space 2 inches wide was left in the middle, 
 and filled up with cement. 
 
 The dam is provided with a drain-pipe, a (Fig. 181), just above 
 the floor, and a manhole pipe, 5, 20 inches (0-5 m.) in diameter 
 clear ; d and e are two of the four pipes taking the compressed 
 
 FIG. 181. 
 
 M i 0-5 
 
 FT.O 
 
 U 
 
 14. 
 
 is 
 
 FLIT 
 
 air into the workings. Each pipe hns a strong cock, and the 
 manhole cover carries a pressure-gauge. The drain- pipe a is 
 opened at least once a day, to blow off the dirty water which accu- 
 mulates. 
 
 The underground reservoirs have several advantages. In the 
 first place they cost only one-third of what they would have done 
 if constructed of sheet-iron ; secondly, they serve as accumulators, 
 and by storing up power make the machines far more independent 
 of the compressors. Even if the compressor stops for a time, the 
 underground machinery can go on working ; besides, when the 
 reservoir is at the surface, the machines nearest to it get a better 
 
 * Schrader, "Die neueren Fortschritte bei der Anwendung von Gesteins- 
 Bohrmaschinen und die Versuche mit kleinen Schrammaschinen bcirn 
 Mansfelder Kupferschijferbergbau," Zcitschr.f. B.- IL-u. & Wesen, voLxli., 
 1893, P- 119. 
 
1 7 o OHE AND STONE-MINING. 
 
 supply than those at a distance. A third advantage is the puri- 
 fication of the air, which deposits moisture, particles of dust, and 
 lubricants. Lastly, an underground reservoir cannot explode. 
 
 The compressed air of a surface reservoir is conveyed into the 
 mine by mains. They are often made of cast-iron with flange 
 
 FIG. 182. 
 
 FIGS. 183 & 184. 
 
 joints of some kind. Fig. 182 gives the joint used by Mathet at 
 Blanzy for the pipes going down the shaft, which are 4^ inches 
 (120 mm.) in diameter inside. The joint is made air-tight by an 
 india-rubber washer, placed in the groove shown in the upper 
 flange, which is squeezed tight when the two flanges are drawn 
 together by five bolts. The manner in which the pipe is sup- 
 ported in the shaft is rendered plain by Figs. 183 and 184 (the 
 dimensions are in millimetres). Cross-beams are put in at intervals 
 of about 100 yards, and the pipe is further kept in place by iron 
 clamps driven into the brick lining of the pit every 20' yards. 
 
BREAKING GROUND. 171 
 
 Messrs. Eadie & Sons have several joints for lap- welded wrought- 
 iron and steel pipes used in conveying air, steam and water, among 
 which maybe specially mentioned the one represented in Fig. 185. 
 In this case each end of the tube is turned up so as to form a 
 small flange, after a loose ring has been slipped on. The loose 
 rings are made with spigot and faucet, which can be drawn 
 together by four bolts, and thus made to squeeze an india-rubber 
 washer placed between the two pipes. Joints of this description 
 are very easily and quickly made, and are found to remain staunch ; 
 they, therefore, commend themselves to the miner. The 
 lap-welded wrought-iron and steel tubes have the advantage of 
 lightness and cheapness, and as they are tested to at least 700 
 Ibs. per square inch they are fully strong enough to stand far 
 greater pressures than are met with in the air-mains of mines. 
 In America the line of welding is sometimes spiral instead of 
 longitudinal ; and in this country Rylands' glass-lined iron pipe, 
 3 inches in diameter internally, has been chosen in one case for 
 the sake of lessening the friction. 
 
 The air-compressors furnishing supplies to the Chapin Mine, 
 Michigan, are situated at a distance of three miles from the work- 
 ings, in order to take advantage of the Quinnesec Falls as a source 
 of power. The main leading from the compressors is a riveted 
 pipe made of |-inch wrought-iron, 24 inches in diameter, in lengths 
 of 48 feet, and having expansion joints every ten lengths. 
 
 For branches conveying air from the mains to the actual work- 
 ing places, gas-pipe with screwed sockets is largely employed. 
 Finally, when the machine has to be shifted continually, there is 
 a piece of india-rubber hose, which should be covered in some 
 way, so as to prevent its being unnecessarily worn when being 
 dragged about over rough surfaces. Wire wound round the hose 
 adds greatly to its durability. Flexible metallic tubing has been 
 used with success in the place of india-rubber hose. 
 
 Water. Force-pumps at the surface are made to drive water 
 through pipes to places underground where hydraulic engines are 
 worked by its pressure. They may be aided by an accumulator ; 
 that is to say, a cylinder into which the water is forced so as to 
 lift a plunger supporting a heavy weight. The accumulator 
 serves to regulate the load upon the engine working the force- 
 pump, and to store up power while the mining machinery happens 
 to be idle. It acts, in fact, like the reservoir used with an air- 
 compressor. A second method of utilising power at the surface 
 consists in drawing off water in pipes from the rising main of the 
 pumps. In both these cases any natural fall of the water adds its 
 effect to that produced by the engine above ground. 
 
 Hydraulic power has the great convenience, therefore, that it is 
 sometimes obtainable without any extra plant being required. 
 The water, after having done its work, runs out naturally if the 
 workings are above an adit, but has to be pumped up if they are 
 
172 
 
 ORE AND STONE-MINING. 
 
 below it. However, it may be cheaper and easier to work the 
 pump a little faster than to erect special air-compressing plant. 
 Hydraulic power has the disadvantage, compared with pneumatic 
 power, of not ventilating the workings, and, as already pointed 
 out, of being objectionable with certain rocks. 
 
 Electricity. This method consists in driving a dynamo by any 
 available power at the surface, and then conducting the current 
 by wires to an electric motor underground. The possibility of 
 conveying power by wires is an immense convenience to the miner. 
 The advantages, compared with transmission by air or water, are 
 that it is much easier to fix wires than pipes ; wires occupy much 
 less room, and do not suffer like pipes from movements of the 
 rocks due to the workings. Like water, but unlike compressed 
 air, electricity does not assist in ventilating the working place, 
 and in fiery mines there may be danger from sparks. 
 
 Messrs. L. & C. Atkinson, in speaking of electric transmission, 
 in a very useful paper,* lately read before the Institute of Civil 
 Engineers, say : " It will be seen that an efficiency of 67 per cent, 
 can readily be obtained even when transmitting nearly 100 h.-p. 
 to a distance of more than two miles, and without any attempt 
 being made to get specially good results, the whole plant being 
 such as can be worked by unskilled men." 
 
 The following table has been prepared by Messrs. Atkinson to 
 show the relative cost of transmitting power by compressed air 
 and by electricity : 
 
 
 O ^ 
 
 2 
 
 om en- 
 motor 
 
 o 
 
 Hi 
 
 o 
 
 at 
 
 O 
 
 s 
 
 11 
 
 . 
 
 System. 
 
 SB ? 
 
 x3 
 
 I-S-5 
 
 
 -S'c 
 
 S. s, 
 
 v 
 
 S s 
 
 .1 
 
 
 s a 
 
 U g 
 
 i da 
 
 o ^ 
 
 ^ o 
 
 O p^ 
 
 
 c * 
 
 j 
 
 
 
 "co 
 
 
 
 c ^ 
 
 
 8 
 
 ' c: o 
 
 o 
 
 
 a 
 
 * 
 
 I-5.S 
 
 go 
 
 i, rt 
 
 PH 
 
 PH 
 
 o -w 
 
 H 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 ^ 
 
 
 Electric . 
 
 I5'4 
 
 10 
 
 20CO 
 
 TV in- 
 
 210 
 
 192 
 
 95 
 
 497 
 
 65% 
 
 Compressed air 
 
 33 '3 
 
 10 
 
 2000 
 
 4 ins. 
 
 130 
 
 700 
 
 63 
 
 893 
 
 30% 
 
 Compared with compressed air, the plant is less expensive, and 
 there is the immense advantage of a smaller loss of power in 
 transmission. f According to experiments made with the electric 
 p^int at St. John's Colliery, Normanton, and Llanerch Colliery, 
 Monmouthshire, the efliciency of the plant i.e., the ratio between 
 
 * Proc. Inst. Civ. Eng., vol. civ. Session 1890-91, p. 89. 
 
 t Siiell, "Electrical Transmission of Power in Mining Operations." 
 Paper read before the Lancashire Branch of the National Association of 
 Colliery Managers, Wigan, September 28, 1889. 
 
BREAKING GROUND, 173 
 
 the work done in pumping and hauling by the electric motor, 
 and the work given out by the steam engine at the surface is 
 as much as from 43 to 48 % . 
 
 Making every allowance for the fact that these figures are 
 given by avowed advocates of electricity, it undoubtedly seems that 
 compressed air is at a disadvantage as regards cost and efficiency 
 when compared with its youngest rival. 
 
 A combination of electricity and compressed air has been 
 found advisable in some cases. The power is transmitted under- 
 ground by electricity to motors which drive small air-compressors 
 placed in the vicinity of the working places where percussive 
 drills are required. 
 
 Hitherto the principal applications of electrical transmitting 
 plant have been for pumping, winding, and hauling, and little 
 has been done in the way of machines for breaking ground ; but 
 rotary and percussive drills driven by electricity are already 
 beginning to be employed. 
 
 EXCAVATING MACHINERY. The machines used for 
 excavating may be classified as follows : 
 
 (1) Diggers. 
 
 (2) Dredges. 
 
 (3) Drills for boring holes for blasting or wedging. 
 
 (4) Machines for cutting grooves. 
 
 (5) Machines for excavating complete tunnels. 
 
 I. Steam Digger. The steam navvy, though specially the 
 machine of the railway or canal engineer, must not be forgotten 
 by the miner, who has to excavate large quantities of com- 
 paratively soft deposits near the surface, or to remove overburden 
 such as sand, gravel, stiff clay, or chalk. After a preliminary 
 shattering by blasting, even hard rock may be shovelled up by 
 these machines. 
 
 Among them we may mention Dunbar & Rustorts Steam Navvy* 
 (Fig. 1 86), largely used in making the Manchester Ship Canal. It 
 is a steam crane which brings a bucket, armed with teeth and a 
 sharp edge, against the side of the excavation, draws it up and 
 drops its contents into a railway waggon. The figure needs but 
 little explanation. A is the vertical boiler giving steam to two 
 cylinders, one of which is shown at B. These are made to work 
 drums for raising and lowering the bucket C, by the chain D, 
 or for turning the jib G. 
 
 In order to work the navvy the bucket is lowered till the 
 handle E is vertical ; it is then brought against the bottom of 
 the working face, and drawn up by the chain D; the teeth 
 enter the earth and open the way for the cutting edge. The 
 bucket fills itself, is swung over the waggon by the jib, and 
 
 * Mining Journal, vol. Iviii (iTSS), p. 1242. 
 
174 
 
 CUE AND STONE-MINING. 
 
 Emptied by pulling the cord H. It closes automatically when 
 lowered. 
 
 The depth of the cut depends upon the length of the radius given 
 to the circular arc described by the cutting tool. The radius, 
 and therefore the cut, can be altered by a man, standing at the 
 foot of the jib-post, who works the chain F; this actuates a 
 pinion gearing into a rack upon the bucket handle E. 
 
 The navvy requires three men, one attending to the raising 
 and lowering of the bucket and swinging of the jib ; a second 
 regulating the depth of the cut and the discharge, and lastly a 
 
 FIG. 186. 
 
 fireman. Each bucket contains I to ij cubic yards, and 
 three buckets will fill a contractor's waggon. In ten hours this 
 machine will excavate and load from 700 to 1000 cubic yards of 
 earth. 
 
 When all the earth within reach has been excavated, the jack 
 screws are loosened and the machine made to propel itself forward 
 on the rails a few feet. 
 
 A somewhat similar machine is Wilson's Steam Crane Excavator. 
 It is a 10 ton steam crane to which a digging bucket can 
 speedily be attached. The machine can therefore be used as a 
 crane or as a digger, as occasion requires. 
 
 This is also possible with the Whittaker Excavator, which, like 
 the two previous steam navvies, has been used for making the 
 Manchester Ship Canal. 
 
 Steam diggers are much used by miners and quarriers in the 
 United States, and especially the machines made by the Marion 
 and the Bucyrus Steam Shovel Companies, which in principle 
 resemble the Dunbar and Huston Navvy. The Earnhardt Steam 
 Shovel of the former company is employed in the Mesabi Range, 
 
BREAKING GROUND. 175 
 
 Minn., and in other places, for stripping off overburden and for 
 excavating iron ore, and the Bucyrus Company applies its digger 
 with success to auriferous gravel, instead of washing it down by 
 the hydraulic process. 
 
 Besides serving as true excavating machines, these steam 
 shovels are found economical for loading ore from stock piles into 
 railway waggons. 
 
 Another kind of digger may be spoken of as a dry dredge ; a 
 machine of this class, made by a Liibeck Company,* is in use, 
 among other places, at a large openwork where brown coal is 
 being worked near Briihl, between Bonn and Cologne. The 
 excavating part of this steam digger consists of a long arm with 
 a chain of buckets, like those of a dredge, which are brought 
 successively against the face of the overburden and then carry the 
 gravel into a hopper; side-tipping waggons are run under this 
 hopper and quickly filled by opening a door. 
 
 The pulley which makes the endless belt of buckets revolve is 
 set in motion by friction gear, so that there is no fear of a break- 
 age, even when a bucket comes against some very hard place in 
 the overburden which it cannot penetrate. The arm carrying the 
 buckets can be raised and lowered as required. 
 
 Theoretically this machine will excavate 1000 cubic metres 
 (1300 cubic yards) in ten hours; the actual work is stated to be 
 about 700 cubic metres (915 cubic yards) in that time. 
 
 The Bucyrus Steam Shovel Company likewise makes a machine 
 of this type. 
 
 II. Dredges. The beds of rivers and lagoons, and even sea 
 beaches and bottoms, sometimes contain minerals which can be 
 excavated by dredges like those used for improving harbours. 
 There are three types : 
 
 (1) Bucket dredges. 
 
 (2) Grab dredges. 
 
 (3) Suction dredges. 
 
 i. Bucket Dredges. Kincaid & McQueen's machine (Fig. 187), 
 used with success upon the Molyneux river,f New Zealand, is a 
 big barge, 66 feet long, with an endless chain of buckets and a 
 pontoon on each side. The total width of the barge and two 
 pontoons is 26 feet. 
 
 The buckets are worked by a steam-engine upon the barge, 
 which also drives a cylindrical screen for separating any large 
 stones. The engine is a vertical inverted compound steam-engine, 
 with cylinders of 12 inches and 22 inches diameter respectively, 
 and 1 8 inches stroke, working at a pressure of 60 Ibs. per square 
 inch. 
 
 Liibecker Mascbinenban Gesellscbaft." 
 
 t Mines Statement. By the Minister of Mines, the Hon. W. J. M. 
 Larnach, C.M.G. Delivered July 6, 1886, p. 17. 
 
i 7 6 
 
 OEE AND STONE-MINING. 
 
 The buckets can be made to raise as much as 150 tons of stuff 
 per hour, and to excavate to a depth of 25 feet below the level of 
 the water. A steam winch serves for raising and lowering each 
 
 FIG. 
 
 of the dredging ladders, or frames, carrying the endless chains of 
 buckets, and also for working the mooring chains. 
 
 A dredge of a similar kind has been used on the river Oreo, in 
 Piedmont,* for the purpose of excavating an auriferous alluvium 
 in order to extract gold from it, and with the further object of 
 preventing floods by straightening the course of the river and 
 embanking it. 
 
 The dredge has an engine of 50 h.-p., and is said to be capable 
 of raising 3200 cubic yards of alluvium (2500 cubic metres) in 22 
 hours. It can excavate to a depth of 26 feet (8 m.). 
 
 2. A grab dredge consists of a single hemispherical or semi- 
 cylindrical vessel, which is made so that it opens when lowered, 
 fills itself on touching the earth and closes as soon as it is raised . 
 The raising and lowering are done by a crane. The semi-cylindrical 
 bucket may be armed with teeth ; it descends with the teeth open 
 and is drawn up with them closed. 
 
 Bruce & Batho make some of their grabs with three or four 
 sharp blades, like very pointed spades, which close upon being 
 lifted, and form a hemispherical bucket. A somewhat similar 
 grab dredge has been employed for stripping off the overburden 
 from a bed of auriferous gravel in California.'!' 
 
 The Priestman Grab dredger has been used for excavating the 
 
 * Gazzettadi Torino. May u, 1886. 
 
 t Eighth Annual Report of the State Miner alofj'st, for the year iSSS, 
 Sacramento, i8S8, p. 100. 
 
BREAKING GROUND. 
 
 177 
 
 auriferous gravel of the river Nechi and its tributaries in the 
 United States of Colombia (Fig. 188), and it likewise serves as 
 a digging machine on land, and even for sinking shafts. 
 
 FIG. 1 88. 
 
 3. The Suction dredge may be described very shortly as a cen- 
 trifugal pump arranged to draw up sand and gravel with the 
 water. It is placed upon a barge, and the suction pipe can 
 be lowered, raised, or moved from one side to the other, so as 
 to attack any part of the sea or river-bottom. A Welman 
 dredge of this type,* used for excavating the ocean beach at the 
 mouth of the Waipapa Creek, has suction and delivery pipes 1 2 
 inches in diameter. It appears to be doing excellent work where 
 the bulk of the material to be treated consists of sand and fine 
 shingle. The beach is reckoned to yield about 3 grains of gold 
 per ton, whilst the working expenses are only 2 grains per ton. 
 
 III. Rock Drills. Most of the machine drills have a per- 
 cussive action, but a few are rotary ; for Stapff pointed out some 
 years ago that if a rock may be chipped off by power communi- 
 cated by a blow, it may also be chipped off by a similar amount 
 of power communicated by pressure. 
 
 i. Rotary Drills. Following the order I have adopted in 
 
 * Parliamentary Eeports on the Mining Industry of New Zealand. Wel- 
 lington, 1890, p. 87 ; and 1891, p. 75. 
 
 SI 
 
i 7 8 
 
 OIIE AND STONE-MINING. 
 
 the case of the hand tools, I will first speak of the rotary 
 machines. 
 
 Brandt's rotary drill consists of a hollow borer which has a 
 steel crown, with cutting edges, screwed on. The tool is kept 
 tight against the rock by the pressure of a column of water, and 
 is at the same time made to rotate by two Jittle water-pressure 
 engines, whilst a stream of water passing down through the 
 borer washes away the chips and sand, and keeps the cutting 
 edges cool. In principle, therefore, this drill resembles the 
 original diamond boring machine of De la Roche Tolay and 
 Ferret, save that the crown is made of steel and not of diamonds. 
 It has been used with success in railway tunnels and mines. 
 
 Brandt's machine was worked at one of the mines at Freiberg* 
 in Saxony, with water at a pressure of 83*5 atmospheres, of which 
 56*6 atmospheres were obtained by pressure pumps provided with 
 an accumulator, and 26-9 atmospheres by natural fall, owing to 
 the level in which the machine was used being 277 metres below 
 the pump. The water was conveyed to the pump in iron pipes 
 ij inches in diameter inside. The diameter of the holes 
 was 2 1 inches, and they could be bored in gneiss at the rate of 
 1 1 inches per minute. The stretcher bar on which the machine 
 is carried is hollow, and has a piston which can be forced out by 
 hydraulic pressure so as to fix it firmly. A similar bar is some- 
 times used with percussive drills. f 
 
 Comparative experiments were made at Freiberg between this 
 drill, hand-labour, and a percussion drill, and the results given 
 below are of much interest and importance. In the case of the 
 two machine drills, the cost includes interest on and depreciation of 
 plant, repairs, and the estimated expense of providing steam 
 power, which would have been necessary if water power had not 
 been available : 
 
 
 Hand boring. 
 
 Schnm's 
 dr.ll. 
 
 Brandt's 
 drill. 
 
 Distance driven per week in 
 
 
 
 
 metres . . 
 
 0'95 
 
 4*5 
 
 5'o 
 
 Cost in marks per metre driven 
 
 120-134 
 
 77-4-85-25 
 
 74*34 
 
 Wages realised by the miners in 
 
 
 
 
 marks, per eight-hours shift , 
 
 1-85-2-05 
 
 3-48-3-66 
 
 376 
 
 The benefits of machine work are very marked indeed, both as 
 regards rate and cost of driving, and wages earned by the men. 
 
 Brandt's rotary drill did its work cheaper and faster than 
 Schram's machine ; but nothing is said in the original notice of 
 
 * JaJirbuch fur das Berg- und Huttenwesen im Konigreiclie Sachsen auf 
 das Jahr 1882, p. 18. 
 
 t Ann. Mines. Ser. 8, vol. ii. 1882, PL I., Fig. 6. 
 
BREAKING GROUND. 
 
 179 
 
 the advantage of a machine driven by compressed air for venti- 
 lating workings, such as advanced headings in which these drills 
 are employed. 
 
 In Jarolimetis* drill the borer is likewise a rotating tube 
 armed with steel teeth, but it is fed towards and pressed against 
 the rock by a differential screw arrangement. Water passing 
 through the hollow borer keeps the teeth cool and carries away 
 the debris. The machine can be worked by hand, but a little 
 water-pressure or compressed-air engine, or an electric motor will 
 be preferable. 
 
 Experiments have been made lately at Zauckerode,f in Saxony, 
 with a diamond drill for boring holes for blasting. 
 
 The machine is a steel tube with a steel crown screwed on, con- 
 taining four black diamonds ; it is driven by a small electric motor 
 upon a carriage on wheels in the level, by means of a shaft with 
 two universal joints. This arrangement allows holes to be bored 
 in any direction required for driving the tunnel. The holes are 
 from i-i inch to 1-3 inches (28 to 34 mm.) in diameter. 
 
 The result of the experiments is that in hard clay-slate with 
 numerous veins of quartz, or in gneiss, granite, or rocks of similar 
 
 FIG. 189. 
 
 hardness, a level can be driven nearly twice as fast as by hand, 
 and at about the same cost. 
 
 It is also possible to attach a motor of some kind to a twist 
 
 * Oest. Zeitschr. f. B.- u. ff.- Wesen, vol. xxix. (1881), p. 184; and vol. 
 xxx. (1882), p. 103. 
 
 t Georgi, "Die Diamant-Bohrmaschine mit elektrischem Antriebe am 
 komglichen Steinkohlenwerke zu Zauckerode," Jahrb.f. d. Berg- und Hut- 
 tenicesen im Konigreiche /Sachsen auf das-Jahr 1890, p. 95. 
 
i8o 
 
 ORE AND STONE-MINING. 
 
 drill similar to Elliott's hand tool already described. The Jeffrey 
 Manufacturing Company, Columbus, 0., have well- designed drills 
 
 of this class driven by air or elec- 
 tricity. 
 
 For working the Cleveland iron- 
 stone, Mr. Steavenson* is employing 
 twist drills driven by water-power, 
 petroleum engines or electricity. His 
 latest drill is shown by Fig. 189 : A, 
 electric motor ; B, hollow arm with a 
 shaft inside driven by A, and work- 
 ing the bevel wheel C by suitable 
 gearing ; D, twist drill ; E, socket for 
 drill; F, universal joint connecting 
 the feed-screw G, to the drill-socket ; 
 H, feed-nut. Fig. 190 is a similar 
 drill worked by a Priestman petro- 
 leum engine.f 
 
 The cost per ton of getting the 
 Cleveland ironstone has been greatly 
 reduced by the adoption of these 
 machines in the place of hand -labour ; 
 but, as is usually the case, the cost of 
 explosives per ton of stone broken has 
 increased, because holes are bored so 
 easily and quickly that less care is 
 taken in planning them. The extra 
 cost of powder is more than repaid 
 by the saving in labour. 
 
 The Sprague Electric Railway and 
 Motor Company of New York 1 have 
 a small electric rotary diamond drill 
 for boring holes for blasting. The 
 motor is light and carefully cased in to 
 preserve it from dust and dirt ; it is 
 mounted upon an adjustable stretcher 
 bar, and it drives the drill direct. 
 
 2. Percussive Drills. Machine 
 drills are usually designed with a 
 view of carrying out the three opera- 
 tions of hand-work viz., the blow, 
 
 * Steavenson, " On the System of Work- 
 ing Ironstone at Lumpsey Mines by Hy- 
 draulic Drills," Proc. N.E. Inst. M. and M. 
 Eng.. vol. xxxvi. (1886-87), p. 67. 
 
 t Unwin, "Petroleum Engines," Proc. Inst. C.E., vol. cix. (1891-92), 
 part iii. 
 
 J Eng. Min. Jour., vol. xlix. (1890), p. in. 
 
BREAKING GROUND. 
 
 181 
 
 the rotation, and the advance. As a rule a percussive drill consists 
 of a cylinder with a piston, which is moved backwards and forwards 
 by compressed air ; the cutting tool or chisel is firmly attached 
 to the piston rod, made specially strong to stand the great amount 
 of shock to which it is subjected. " The rotation is almost always 
 effected by a twisted or rifled bar and a ratchet wheel ; and, in 
 order to keep the machine constantly in the proper position for 
 work, it is fed forwards upon a cradle by the workman behind, 
 who has merely to turn a handle, and so cause a screw to revolve 
 inside a big nut attached to the machine. Drills which will 
 advance automatically have been invented and used in some 
 cases, but as a rule nowadays the automatic feed has been 
 given up ; indeed, it seems quite unnecessary to increase the 
 number of the working parts and make the machine more com- 
 plicated, simply to save the attendant the trouble of turning a 
 handle. 
 
 Though the plain chisel-shaped edge is the commonest form 
 given to the bits used with machine drills, it is by no means uni- 
 versal ; other forms shown in the figures are the cross-bit, the 
 
 FIG, 191. 
 
 FIG. 192. 
 
 FIG. 193. 
 
 FIG. 194. 
 
 X-bit, the Z-bit, and the horse-shoe bit (Figs. 191, 192, 193, and 
 194). The object in all cases is to secure a perfectly round hole 
 and so prevent jamming. If a band of hard rock crosses a hole 
 in a slanting direction, the single- edged bit is apt to be diverted 
 by it slightly, and become fast. At the outset also, when the 
 drill is striking an uneven surface, it is not always easy to bore 
 the hole properly ; for this reason the first drill is sometimes 
 made with the cross-bit, whilst the remainder of the hole is bored 
 with the single chisel-edge, which will work properly when the 
 hole is deep enough to act in some way as a guide for the tool. 
 
 Bits with two or three edges are not so easily sharpened as 
 those which have but one ; however, the work of the smith may be 
 lightened by using a swage (dolly, U.S.A.), which is, practically, 
 a steel mould, into which one end of the steel bar is placed when 
 soft, whilst blows are struck upon the other end. This gives the 
 proper shape, and the smith can finish up the bit upon the anvil. 
 
1 82 ORE AND STONE-MINING. 
 
 The adoption of the ingenious-shaped bars of the Crescent Steel 
 Company of Chicago (Fig. 195) will likewise relieve the smith, but 
 
 the saving of labour at the forge is 
 FIG. 195. not the only advantage claimed for 
 
 the invention. The shaped steel will 
 discharge the debris more freely than 
 round steel, a matter of no slight 
 importance, for the cleaner the hole 
 the more effective the blow ; the little 
 chips should be got rid of as soon 
 as possible, and any means of facili- 
 tating the discharge should be welcomed. A represents the 
 pattern made originally for the iron mines of Lake Superior, and 
 B the section preferred in the Rocky Mountains. 
 
 Less sharpening is required when boring by a machine than 
 when boring the same depth by hand, and for two reasons : first, 
 the bit suffers less, because the blow given by the machine is 
 straighter and fairer ; and secondly, owing to the greater force 
 of the blow work can be done by the tools when they have become 
 very much blunter than those which would be put aside in hand- 
 drilling. For machine-drilling in soft sandstone in Ohio, the 
 borer is made with a narrow but perfectly flat bit, instead of being 
 chisel-shaped. A flat-ended borer is likewise used by the Inger- 
 soll-Sergeant Rock Drill Company for boring elongated holes by 
 the Githeus system. The tool does not rotate, and acts by pound- 
 ing the bottom of the hole to dust. The object of the elongated 
 hole is to make the rock rend along a pre-arranged line, a matter 
 of importance in quarrying certain kinds of stone. 
 
 Percussive drills may be classified according to the power used 
 for driving them, and those worked by air may be further sub- 
 divided according to the kind of valve employed for reversing 
 the direction of the stroke. 
 
 The following table contains a list of several well-known drills, 
 arranged according to their mode of action and alphabetically : 
 
BREAKING GROUND. 
 
 PERCUSSIVE DRILLS. 
 
 183 
 
 Power. 
 
 Kind of distributing valve. 
 
 Name of the 
 drill. 
 
 
 
 
 Barrow 
 
 
 
 
 Climax 
 
 
 / 
 
 (1) Valve worked by mechanical 
 
 
 Dubois and 
 
 
 
 connections 
 
 
 Franois 
 
 
 
 
 
 Holman 
 
 
 
 
 
 Rand 
 
 
 
 
 
 Rio Tinto 
 
 
 
 
 
 Eickle 
 
 
 
 (2) Air-driven valve . . 
 
 
 Coles 
 Eclipse 
 
 
 
 
 
 Optimus 
 
 Compressed air ( 
 
 
 (3) Valve worked by mechanical 
 
 
 Franke 
 
 
 
 connections and air pressure . 
 
 
 Hirnant 
 
 
 
 (4) Two valves, a main one air- "j 
 
 
 
 
 driven, and an auxiliary one [ 
 worked by mechanical conncc- F 
 
 Sergeant 
 
 
 
 tions J 
 
 
 
 
 ( 
 
 Adelaide 
 
 \ 
 
 (5) No valve . . . .4 
 
 Darlington 
 Minera 
 
 Electricity . . 
 
 
 Marvin 
 
 For the purposes of this work it will be quite sufficient to de- 
 scribe only a few of these machines, especially as in many 
 instances there is a great similarity between them. 
 
 (i) The Barrow drill* (Fig. 196) consists essentially of a gun- 
 
 FiG. 196. 
 
 metal cylinder C, about 2 feet in length and 4 inches in diameter, 
 in which works a cast-steel piston-rod D, fitted with two 
 pistons G, about 12 inches apart, midway between which is the 
 
 * George Seymour, " On the Barrow Rock Drill," Proc. Min. Inst. Corn- 
 wall, vol. i. (1876-83), p. 12. 
 
184 
 
 ORE AND STONE-MINING. 
 
 tappet or boss G'. In a valve-box at the top of the cylinder is 
 placed the oscillating slide-valve H (shown separately), pivoted 
 at M ; it is worked by the reciprocation of the tappet G' 
 coming in contact with its lower edges, which, for this purpose, 
 are sloped at each end, as shown. 
 
 There are ports, corresponding with openings in the slide-valve 
 face, for admitting the fresh steam or compressed air from the 
 inlet pipe I (Fig. 197) to the ports ^ (Fig. 196) at each end of the 
 cylinder, and for letting the spent or exhaust air or steam escape 
 by the exhaust pipe J (Fig. 197). This simple arrangement con- 
 stitutes the whole valve gear of the machine. 
 
 " The borer is inserted into a hole formed in the fore-end of the 
 piston-rod, and is fixed therein by means of a screw. Its rotation is 
 effected by hand by means of the handle D" turning a spindle D', 
 
 which is so fitted by means of the cotter d, made fast in the piston 
 DG, and fitting in a slot in the spindle D', that the latter can 
 slide in the piston DG, but when turned by the handle causes 
 the piston to turn with it. The spindle D' has a pinion E, gear- 
 ing into a pinion on the adjusting and feeding screw C', so 
 that when the piston D is turned by means of the handle D", the 
 cylinder C is simultaneously pushed along the bed-plate A. These 
 pinions can be easily disconnected by loosening the nut f, and 
 thus the piston and the adjusting screw can be turned inde- 
 pendently of one another when required. 
 
 " The borers used are respectively i J, i J, and i inch in diameter, 
 the length of the stroke 4 inches, and the maximum number of 
 blows about 300 per minute. 
 
 " The gross weight of the machine, including the bed-plate and 
 gudgeon, is about 115 Ibs. 
 
 " The bed-plate, A, of the machine is formed with a gudgeon 
 A', which fits into and can be adjusted to any position in a socket 
 formed in or on a clamp B', which can be fixed on any part of 
 the wrought-iron box or column B, thus forming a universal 
 joint. This bar or column can be placed in position either 
 horizontally or vertically, as may be most convenient, but is 
 
BREAKING GROUND. 
 
 -85 
 
 generally placed across the level, against the sides of which it is 
 secured by means of the clamp L, adjusting screw M, and claws 
 N and NV Pieces of wood O', are placed against the wall, 
 and the claw is jammed against them by screwing out the bar. 
 
 The Climax Drill* (Fig. 198) recalls the Barrow; A is the 
 cylinder, B B are the two pistons, and C the boss or swelling which 
 strikes the valve D and rocks it up and down on the centre pin E. 
 The valve has two admission ports, F and F', which, when passing 
 corresponding ports in the valve-chest face, allow the compressed 
 air to pass into G or G'. On the inner lace of the valve, above F 
 and F', there are two recesses, precisely similar to H and H', 
 which control the two ports on each side of the valve-chest face. 
 In the position shown in the figure, the compressed air could pass 
 from the valve-chest through F' into G' and drive the piston 
 
 FIG. 198. 
 
 AJ.. 
 
 forward, whilst the air in the front part of the cylinder would 
 escape by G, which is now put into communication with the 
 exhaust port by the recess above F. The object of the two recesses, 
 H and H', is to enable the valve to be reversed when one face is worn. 
 The rotation is effected by a rifled bar I at the back end of the 
 cylinder, which projects into a long cavity K in the rear piston 
 and piston rod. It can be turned easily in one direction, but is 
 prevented from moving in the opposite direction by the teeth of a 
 crown ratchet clutch L, a device which is thought by the maker 
 to offer a better guarantee against injury than the ratchet wheel 
 with one or two pawls common in most other drills. When the 
 
 * Figures and descriptions of the Bickle, Climax, Coles, Daw, Eclipse, 
 Ingersoll, and Rio Tinto drills will be found in a paper by Carbutt and 
 D-vey, " On Recent Trials of Rock Drills," Min. Proc. Inst. Meek. Eny., 
 London, March 1891. 
 
1 86 
 
 ORE AND STONE-MINING. 
 
 piston moves forward, the nut in the rear piston passes over the 
 rifled bar, and causes it to turn round, but when the motion 
 of the piston is reversed the rifled bar is prevented from turning 
 by the ratchet clutch, the piston is forced to rotate, and with 
 it the borer. M is the feed -screw worked by a handle not shown 
 in the figure, and N the feed-nut. 
 
 The Dubois and Francois Boring Ram (Bosseyeuse)* is a machine 
 of a totally different type (Figs. 199 and 200) ; it bores large holes 
 for the insertion of a wedge, and it is fitted with a ram for driving 
 in the wedge, and so breaking the rock. 
 
 The machine has been specially designed for driving levels in 
 mines where there is so much fire-damp as to render blasting 
 
 FIGS. 199 & 200. 
 &&&SS&&S&&S&; 
 
 SCALE OF MCTftES 
 
 i^ a >v^x^^^^^ 
 
 
 53?^^^^ 
 
 ^ 
 
 SCALE OF FEET 
 
 dangerous, and it therefore more especially concerns collieries 
 than ore and stone mines ; but it should be mentioned in connec- 
 tion with the latter, because it will also bore holes for blasting, 
 and because it is sometimes used for cutting a series of holes, and 
 so creating a first opening, which enables blasting to be conducted 
 with greater advantage (Fig. 239). 
 
 The boring cylinder, A, has a long piston B, with spiral grooves 
 which produce the rotation by means of a ratchet wheel C, whilst 
 the slide-valve, which effects the distribution, lies in the valve- 
 cliest F, and is brought into action when a swelling, D, on the 
 piston-rod touches a bent lever E. 
 
 The borer, G, is fixed in the end of the piston-rod, and makes 
 a hole 3 or 4 inches in diameter. As the hole is deepened, the 
 
 Mathet, Dalr comprime aux mines de Blanzy, Saint-Eticnne, 1889, p. 66. 
 
BREAKING GROUND. 187 
 
 cylinder is made to travel along the frame, H, by means of 
 a screw, and at the same time the counterpoise, I, is also moved 
 by a screw so as to balance it. The machine can be made to turn 
 round the central column, and can also be moved in a vertical 
 plane, so that holes may be bored in any direction ; and the 
 special carriage in use at the Blanzy mines permits the machine 
 to be moved laterally, and take a position near the side of the 
 tunnel. 
 
 The whole machine is very heavy, weighing no less than 2 tons 
 13 cwt. (2700 kil.); but it is found that the greater power and 
 stability so obtained fully compensate for any inconvenience 
 caused by its weight. 
 
 At Blarizy one boring ram has taken the place of four small 
 drills mounted upon one stand ; and this diminution in the 
 number of machines requiring attention is no inconsiderable 
 advantage. 
 
 An ingenious contrivance used with the Blanzy boring ram 
 must on no account be passed over viz., the special pipe for con- 
 veying water to the bottom of the bore-hole. A small copper 
 tube (L, enlarged cross-section, Fig. 200) lies in a groove in the 
 borer, and carries in a jet of water which keeps the bit or boring 
 edge quite cool, and washes out all the chippings as soon as they 
 are produced. The tool is thus enabled to work fairly and freely 
 the whole time, and the result at Blanzy has been a great increase 
 both in the speed of boring and in the duration of the bits. 
 
 The water is supplied to the drill by the india-rubber pipe J", 
 which leads to the hollow collar K. The collar is fixed with a 
 water-tight joint upon the drill socket, so that the latter can 
 revolve freely. The water finds its way through a hole in the 
 drill-socket to the outside, when a short piece of india-rubber 
 tube takes it to the copper pipe. The collar is kept in one posi- 
 tion either by a weight hanging down from it, or by a rod which 
 moves forwards with the machine. Care is taken to pass the 
 supply of injection water through wire gauze, to remove any 
 matter which might choke the small copper tube. 
 
 When the necessary holes have been bored, the drill is taken 
 off and replaced by a strong ram or hammer-head, which is made 
 to strike powerful blows upon a wedge between two feathers 
 fitting into the hole. Large masses of rock are broken off in 
 this way, and the level is driven with any required dimensions. 
 
 (2) The American Ingersoll Sergeant Eclipse Drill (Fig. 201) may 
 be taken as an example of the machines having the valve worked 
 by differences of air-pressure, which are caused by the opening and 
 closing of certain passages by the piston in its course. It consists 
 of the following main parts : the cylinder A, the piston M, the 
 piston-rod B, and the valve chest C. The valve is like a D-slide- 
 valve, but its face is turned so as to fit the cylindrical interior of 
 the valve-chest, and it is provided at each end with a piston. It 
 
i88 ORE AND STONE-MINING. 
 
 therefore has the form of a spool or reel enclosing a D-slide-valve, 
 and it moves backwards and forwards on a guide-pin. The air 
 enters the valve-chest at O, and, when the piston has reached the 
 position shown in the figure, it finds its way round the valve to 
 N', enters the port P', and finally reaches the rear end of the 
 cylinder ; when the valve is reversed, it goes past N into P, and 
 to the front end of the cylinder. The port P is shown in the 
 figure communicating by the slide-valve with the exhaust E. 
 The letters S S' represent a shallow recess cut round the 
 piston, in reality making one piston into two ; F F' are two ports 
 leading to the exhaust, and lastly D D' are two small ports which 
 
 communicate crosswise with the ends of the valve-chest; that 
 is to say, D is connected with the end R', and D' with the 
 end R. 
 
 Bearing these details of construction in mind, the action of the 
 drill can be followed. The drawing shows the machine ready to 
 begin its forward stroke. The rear end of the valve- chest is con- 
 nected with D, which is closed by the piston, whilst the front R 
 is open through D' and the annular recess S to the port F' and 
 the atmosphere. The compressed air from O leaking past the 
 rear valve-piston presses upon it and keeps it in the position 
 shown, for any air leaking past the other valve piston at the end 
 R can escape vid D', S, F' and E into the atmosphere. 
 
 We will nor/ suppose that the main piston M is being driven 
 forward by the pressure behind it ; the annular space S gradually 
 approaches the port D, but the length of the groove is so arranged 
 that D' becomes closed just before D is opened to the exhaust. 
 When the new state of things has arisen that is to say, when D is 
 open to the exhaust and D' closed the pressure in the space R' 
 at once drops to that of the atmosphere, and the valve is driven 
 across by the pressure upon the piston at the end R. 
 
 At both ends of the cylinder there is a strong india-rubber 
 washer, protected by a steel washer, which is represented by a 
 black line. If the miner fails to feed his machine forward pro- 
 perly, the elasticity of the washer prevents the end of the cylinder 
 from being broken. The rotation is performed by the usual 
 riiied bar and ratchet wheel, and the machine is advanced by 
 
BREAKING GROUND. 
 
 189 
 
 turning the handle and so causing the carrying nut to move 
 along the feed screw. 
 
 The Optimus drill, invented by Ogle, has two pistons, a large 
 one in front and a small one behind. The compressed air, after 
 acting at the rear end and making 
 
 the tool strike its blow, is led to FIGS. 202 & 203. 
 
 the front end of the cylinder, and 
 pressing upon the large piston 
 drives it back. The inventor claims 
 considerable economy for his drill, 
 because the backward stroke is made 
 with air which usually goes direct 
 to the exhaust. 
 
 Figs. 202 and 203 show one 
 method of attaching the drills to 
 the piston-rod. A is the piston- 
 rod with an enlarged head, H; S is -JNCHES 
 the shank of the tool which is 
 
 gripped in the socket by a chucking- block B, tightened by a 
 U-shaped clamping-bolt C. 
 
 (3) Franke drill* This drill (Fig. 204) is especially interesting 
 from being the smallest and lightest boring machine in actual use. 
 Including the borer, it weighs only 16 Ibs. (7^ kil.), and it may, 
 therefore, be placed at one end of the scale whilst the ponderous 
 "bosseyeuse" of Dubois and Frangois occupies the other. Both 
 in his drill and in his mechanical chisel, Franke adopts the prin- 
 ciple of doing the work by a light blow repeated very rapidly 
 indeed, instead of a heavy blow at less frequent intervals. 
 
 The principal parts of the machine are : A, outer case or shell ; 
 A' t cylinder proper; J3, piston; (7, ring-shaped slide-valve, which 
 can slide backwards and forwards in a short recess in the piston ; 
 I), tool-holder ; E, pipe bringing air ; F, rear end of cylinder 
 proper with admission ports ; 6r, spiral spring ; ff, exhaust 
 port ; /, piston-rod ; J, striking head of piston-rod ; P, pin passing 
 through the piston-rod; a, passage bringing air from F ; 6, port 
 admitting air to slide-valve ; c, one of three longitudinal passages 
 connecting the front end of the piston with the annular recess 
 in which the slide-valve works ; e, one of three similar passages 
 connecting the same recess with the rear end of the piston; 
 y, hollow centre of piston and piston-rod communicating by g with 
 the exhaust port H ; h h, two of the three radial passages which 
 put the slide-valve C into connection with/; i, part of tool-holder ; 
 j, collar preventing the tool-holder from being driven back too 
 far ; I l v straight slots in the shell A o o v oblique slots in the 
 
 * Schrader " Die neueren Fortschritte bei derAnwendungvon Gesteins- 
 Bohrmaschinen und die Versuche mit kleinen Schrammaschinen beim 
 Mansfelder Kupferschieferbergbau," Zeitschr. f. B.- H.- u. S.- Wesen, vol. 
 xli., 1893, p. no. 
 
190 
 
 ORE AND STONE-MINING. 
 
 hollow cylinder q ; q v end of the cylinder q\ rr^ ends of the 
 pin P ; tt, pawls attached to q l u, hexagonal end of the tool- 
 
 u 
 
 5 I 
 
 K> 
 
 holder D ; v, ratchet wheel, which can slide upon u but cannot 
 rotate without it. 
 
 After this description of the parts, the mode of action of the 
 
BKEAKING GKOUND. 
 
 191 
 
 machine can be easily understood. The air is brought by a flexible 
 hose attached to E, and passing along the small passages a outside 
 the cylinder proper, enters it at b. In the position shown in the 
 figure the lower b allows the air to pass into e, press upon the 
 rear end of the piston, and drive it forwards. During this time 
 the air in front of the piston has an escape provided by the passages 
 c, h, f, and g to the exhaust port H. The complete stroke is 
 20 mm. (^ inch), and when the piston has travelled 17 mm., 
 the end of the piston rod J strikes the head u, and the tool 
 does its work at the bottom of the hole, provided of course that 
 the machine is properly held. As the piston goes forwards it 
 draws the slide-valve C with it ; as soon as C has passed the port 
 6, it is driven across the recess and the direction of the air is 
 reversed. The front end of the cylinder is now in communication 
 with the compressed air, whilst the space at the rear end dis- 
 charges its contents vid e, C, h,f, and g into H. The slide-valve 
 C is then again shot across, and air is admitted to the rear end of 
 the piston. The end of the piston-rod, J, is therefore constantly 
 hammering upon u, and after each blow the spring G brings the 
 tool-holder back to its original position. The rotation of the tool 
 is effected in a simple manner. The ends r r l of the pin P are 
 forced to travel in a direct line by the slots 11^ ; but the slots oo^ 
 
 FIG. 205. 
 
 are oblique, and the pin P, therefore, causes the hollow cylinder q 
 to oscillate. During the forward stroke each pawl, t, is drawn 
 over a tooth of the ratchet wheel v ; during the back stroke it 
 turns v slightly, and with it the tool-holder. 
 
192 
 
 ORE AND STONE-MINING. 
 
 The borer is made of round steel f inch (15 mm.) in diameter, 
 with a Z-shaped bit i inch (25 mm.) wide. The number of blows 
 
 has not yet been determined 
 exactly; but it probably 
 reaches 8000 to 10,000 per 
 minute. The moving parts 
 of the machine are constructed 
 of soft tough steel, except the 
 slide - valve, for which good 
 wrought iron appears at present 
 to be the most suitable material. 
 The machine is used without 
 any stand, and is simply held in 
 the hands (Fig. 205, man in a 
 kneeling posture).* 
 
 The Hirnant drill f of Messrs. 
 Larmuth & Co. is a machine with 
 a tappet valve assisted by air- 
 pressure. In Fig. 206, A is the 
 cylinder, B the piston, and G 
 the valve-chamber containing a 
 piston-valve Z), which works over 
 the admission ports E and E f , 
 and the exhaust ports F and F'. 
 G is a tappet, oscillating upon 
 the pin H, when the noses 7 and 
 K are struck by the curved 
 shoulders L and M of an 
 annular recess N around the 
 piston B. 
 
 In the position of the parts 
 as figured, the compressed air 
 brought into the valve-chamber 
 is passing through E' to the rear 
 end of the cylinder, whilst the air 
 in front is in communication by 
 E and F with the exhaust. At 
 the same time the air is also 
 pressing upon the rear end of the 
 piston-valve, for it escapes along 
 the passage O'P' made by planing 
 flat surfaces upon the valve and 
 the inside of the end of the cham- 
 ber. The other end of the valve 
 
 * From a photograph supplied by the makers, Messrs. Friemann and 
 Wolf, Zwickau, 
 t Patent Office Specification No. 10,050, A.D. 1891. 
 
BREAKING GROUND. 
 
 193 
 
 chest is put into communication with the exhaust by the small 
 port Q, and as the flat surfaces P and are not overlapping, 
 there is no passage of compressed air. The pressure upon the 
 rear end of the valve D therefore 
 tends to move it forwards, and assists 
 in moving it forwards, the moment 
 that the nose I can drop down owing 
 to the recess N passing under it. The 
 shoulders L and M would of them- 
 selves move the tappet, but the 
 auxiliary air pressure has the advan- 
 tage of reversing the valve without 
 the shocks which are so destructive 
 to the tappets of many drills. The 
 cushion of air in the space R 1 pre- 
 vents the nose K of the tappet G 
 from striking the recessed part N 
 of the piston. 
 
 The long valve-chest has the ad- 
 vantage of shortening the inlet ports, 
 and so making a saving in the con- 
 sumption of compressed air. 
 
 This drill is further provided with 
 a device for taking up any slackness 
 of the feed-screw and feed-nut due 
 to wear. S is the feed-screw and T 
 the main feed-nut, placed between 
 the two lugs U and Z7", forming part 
 of the same casting as the cylinder. 
 T' is a second nut, and between T' 
 and T there is a space V in which is 
 fitted a spiral spring. T 7 is prevented 
 from turning by having a flat face 
 resting against the cylinder cover. 
 When the feed-screw and the nuts 
 wear, T' is forced away from T by the 
 spring and the slackness is remedied. 
 
 Z is a collar upon a stirrup at- 
 tached to the cradle, and furnishes a 
 point d'appui for the advance of the 
 machine when the screw S is turned 
 by the handle. 
 
 (4) The Sergeant drill has the 
 peculiarity of having two valves, a main valve and an auxiliary 
 valve ; the latter is moved backwards and forwards by inclines or 
 shoulders upon the piston, and, by controlling certain air-passages, 
 it causes differences of pressure which drive the former. 
 
 In Fig, 207 a is the cylinder, b the piston with an annular recess 
 
194 ORE AND STONE- MINING. 
 
 turned in it presenting two inclined shoulders ; c is the valve-chest 
 into which the compressed air enters from one of the sides ; d is 
 the main valve, and as it moves to and fro it alternately places the 
 port e or / in communication with the exhaust g] e leads to the 
 port h and to the front end, and / to the port i and to the rear 
 end of the cylinder ; j, the auxiliary valve, is a slide-valve made in 
 the form of a segment of a circle, and having a recess in one of 
 its flat faces. It is slightly longer than its arc- shaped seat, so 
 that one end of it always projects into the cylinder. The pro- 
 jecting end of the valve is caught by the corresponding shoulder 
 of the piston as it passes, and it is thus being constantly knocked 
 backwards and forwards. By means of its recess this segmental 
 slide-valve puts the ports k and I alternately into communication 
 with the port M, which opens into the exhaust. The port k leads 
 to the front end of the valve-chest, the port I to the rear end; 
 consequently the two ends are being alternately placed in com- 
 munication with the exhaust. The compressed air leaking past 
 the piston-like ends of the main valve escapes into the exhaust at 
 one end of the valve-chest, but exerts a pressure at the other end 
 where it is confined, and so throws the main valve over, changing 
 the direction in which the air is being admitted into the cylinder. 
 The piston makes its stroke, knocks over the auxiliary valve, 
 which in its turn releases the pressure at one end of the main 
 valve and causes it to move across once more. 
 
 The rotation is effected by a rifled bar, n, as usual ; but instead 
 of there being a ratchet-wheel fixed to this bar with pawls attached 
 to the cylinder, the rifled bar carries the pawls which work inside 
 
 a ratchet-wheel, 0, with in- 
 
 FIG. 208. ternal teeth and a smooth 
 
 exterior (Fig. 208). The 
 pawls are pressed out by 
 springs, p (Fig. 207). So 
 far the action is very like 
 that of other drills, save that 
 the pawls move round inside 
 the wheel, instead of the 
 wheel moving round under 
 the pawls. The special 
 peculiarity of the Sergeant rotating device is the mobility of 
 the wheel if the drill jams in a hole. The ratchet-wheel o lies 
 loose in a recess behind the cylinder, and in ordinary working is 
 pressed sufficiently firmly against the end of the cylinder by steel 
 cushion springs to make the piston rotate without turning itself ; 
 but if for some reason the borer jams in the hole and causes a 
 strain upon the rifled bar, the wheel is capable of turning and so 
 preventing a breakage. 
 
 The feed as usual is by hand ; q is the handle working the feed- 
 screw r in the feed-nut s. 
 
BREAKING GROUND. 
 
 195 
 
 (5) In the drills of this class the piston performs a double 
 function ; it not only acts as a medium for receiving the pres- 
 sure of the air, but it also itself uncovers or closes the passages 
 by which the air enters or escapes, and so causes a reversal of 
 the stroke without the intervention of any separate valve. 
 
 The Adelaide drill (Fig. 209) comes first alphabetically, although 
 
 209. 
 
 it was preceded in time by the Darlington drill, of which it may 
 be regarded as a modification. A A represent the annular port, 
 admitting the air all round the piston, and JB / B t are ports in the 
 piston-rod. When the latter are opposite A A, air passes down 
 through the space G in the piston-rod to the rear end of the 
 piston, and drives it forward till it uncovers the port B, which 
 puts this part of the cylinder into communication with the 
 atmosphere. At the same time B t B t have passed beyond the 
 stuffing-box and part of the exhaust escapes in that direction ; 
 while this is happening the long shallow annular recess cut in 
 the piston-rod is brought to A, the air presses on the small 
 annular space at the front end of the piston and drives it back. 
 It will be noticed that this drill uses the air expansively, for 
 when once B t has gone past A no further supply of power is taken 
 in. D is the rifled bar, E the ratchet wheel, H the feed-screw, 
 and G the feed-nut, similar to the corresponding parts of many 
 other machines. 
 
 The construction of the Darlington drill will be understood by 
 referring to Figs. 210, 211, and 212; a is the cylinder; b the 
 piston-rod ; c the borer ; d d are two openings for bringing in 
 compressed air, either of which may be used according to the 
 position of the drill ; e is the inlet hose with a stop-cock ; f t drill- 
 holder ; g } stretcher-bar ; h, piston ; j, rifled bar for turning piston 
 and drill; k, ratchet wheel attached to rifled bar ; I, rifled nut 
 fixed in the piston head ; m, wood for lessening weight of piston 
 rod and blocking space ; n, portway for allowing the compressed 
 air to pass to the rear of the piston and give the blow ; o, exhaust 
 portway. The action of the drill is as follows : The compressed 
 air is always acting on the front end of the piston, and when 
 the rear end communicates with the outer atmosphere, the 
 piston moves rapidly backwards and uncovers the portway n. 
 The compressed air rushes through and presses against the rear 
 
196 ORE AND STONE-MINING. 
 
 FIG. 210. FIG. 211. 
 
BREAKING GROUND. 
 
 197 
 
 end of the piston, which has a greater area than the front 
 end, the difference being equal to the section of the piston-rod. 
 The piston is driven rapidly forwards, and the drill strikes its 
 blow. At the same time it uncovers the exhaust port o, and 
 then the constant pressure on the annular area on the front 
 end of the piston produces the return stroke. The number .of 
 blows per minute is from 600 to 800. The rotation of the drill 
 is effected by the rifled bar. On the forward stroke of the piston, 
 the bar with its ratchet-wheel is free to turn under a couple of 
 pawls, and consequently the piston moves straight whilst the bar 
 and ratchet-wheel turn. When the back stroke is being made, 
 
 F.c. 21 -. 
 
 the ratchet-wheel is held by the pawls and the piston is forced to 
 make part of a revolution. As the hole is deepened the cylinder 
 is advanced forwards by turning the handle p ; this works an 
 endless screw, ?, passing through a nut attached to the cylinder ; r 
 is the cradle carrying the feed-screw and supporting the cylinder. 
 It is centered on the clamp s. As this clamp can be fixed in 
 any position on the bar, and as the cradle can be turned on the 
 clamp, it is evident that holes can be bored in any direction. 
 
 In driving a level with a Darlington drill, it is usual to fix the 
 stretcher-bar horizontally so as to command the upper part of 
 the face ; holes can then be bored with the cradle above the bar 
 or below it. The bar is then shifted low enough to bore the 
 bottom holes. It is found that all the necessary holes can be 
 bored from these two positions of the bar. 
 
 The bar, therefore, has to be fixed only twice ; the shifting 
 of the machine for boring holes in various directions is managed 
 
i 9 8 ORE AND STONE-MINING. 
 
 by sliding or turning the clamp on the bar and by moving the 
 cradle on the clamp. 
 
 Fig. 212 shows the stretcher-bar fixed in a vertical position, 
 which is sometimes convenient. 
 
 In order to keep the holes clear, a jet of water, supplied from 
 a hose attached to a J-inch gas-pipe leading from a cistern at a 
 higher level, is made to play into them during the process of 
 boring. 
 
 For sinking shafts, Mr. Darlington has the drill fixed in a 
 cylindrical case with a large external thread, which works in a 
 nut on the clamp. The drill is fed forwards by turning a hand- 
 wheel attached to the case. 
 
 The Marvin Drill * of the Edison General Electric Company is 
 based upon the principle that a spiral coil of wire assumes magnetic 
 properties when a current is passed through it, and becomes 
 capable of exerting a very strong attraction upon a bar of iron 
 placed in a suitable position. The actual working parts of the 
 
 drill are shown in Fig. 213. 
 
 FIG. 213. A and B are two hollow coils 
 
 of copper wire (solenoids), 
 through which passes the rod 
 C D. The two ends are made 
 of bronze, but the central por- 
 tion, E F, is of iron. At the 
 end C there is a socket for 
 receiving the tool, whilst the 
 end D is rifled and works in a 
 ratchet-wheel, and so effects 
 
 the rotation in the usual way. A current is led to the drill by a 
 cable with three wires, shown separately by G, H, and I, and by 
 means of a very simple revolving armature on the dynamo it can 
 be made to pass, first through one solenoid, and then through the 
 other, in each case returning by the wire H. For instance, 
 we may suppose that the current is passing through the front 
 solenoid ; this becomes magnetic and draws the iron core for- 
 wards, and so causes the tool to strike a blow. The current is then 
 reversed by the revolution of the armature, and flows into the 
 solenoid B, which in its turn becomes magnetic and draws the 
 iron back, for A has lost its magnetic power. The rear end of 
 the rod C D is made to compress a spring, and so store up 
 force which is utilised in increasing the strength of the forward 
 blow. 
 
 The drill makes 600 strokes a minute, and is said to be capable 
 of boring in granite at the rate of 2 inches a minute. 
 
 At the present time there are few, if any, electric percussive 
 drills in regular use in mines, one objection to them being their 
 
 * "Electric Percussion Drills," Eng. Min.Jour., vol. li. (1891), p. 609. 
 
BREAKING GROUND. 199 
 
 great weight compared with air drills of equal strength ; but it is 
 stated that they are doing good work at some open limestone 
 quarries at Svracuso,* N. Y. 
 
 IV. Machines for Cutting Grooves. Tn working a seam 
 the task of the miner frequently consists in cutting a deep 
 groove parallel to the bedding with a pick, and so laying it bare 
 above, below, or in the middle. Wedging or blasting will then 
 break it away. 
 
 The first machines for cutting grooves very naturally imitated 
 the miners' tools, and were simply mechanical picks, but since 
 then many other groove cutters have been applied which are based 
 upon different principles. 
 
 They may be classified as follows : 
 
 1. Mechanical picks, chisels, and gouges. 
 
 2. Travelling jumpers and rock-drills. 
 
 3. Circular saws. 
 
 4. Endless chains with cutters attached. 
 
 5. Wire saw. 
 
 6. Revolving toothed bar. 
 
 (i) Mechanical Picks, &c. Some, like Firttis machine, 
 swing a pick like a miner. The Sergeant machine is a strong rock 
 drill with a chisel bit, which chips out a groove as a carpenter 
 might cut out a mortice. It is mounted on two wheels and can 
 be handled with ease. Carrett and Marshall's machine is a power- 
 ful gouge, worked by hydraulic pressure, which cuts out a groove 
 in coal or soft rocks. These have all been designed more especially 
 for the collier ; but in Frank*? s mechanical chisel (Fig. 214) we 
 have a tool which is being successfully employed in ore-mining. 
 It is based upon the principle of striking a very large number 
 of short and light blows instead of a comparatively small number 
 of long and heavy ones. It resembles in some respects Crossley's 
 mechanical caulking tool and McCoy's chisel. 
 
 The following description is derived from accounts given by 
 Pilaf and Schrader,f and from personal observations at Maiisfeld ; 
 a is the outer shell of the machine, b the inner or real cylinder, c the 
 piston with the annular slide-valve r, d the tool-holder carrying 
 the chisel in a deep socket ; the air is brought in to a by the pipe 
 t, and finds its way into b through four broad, low passages, m m, 
 and sixteen small ports, similar to n n, -j 1 ^ inch in diameter. The 
 front part of the outer shell, a', serves as cylinder cover and as 
 guide for the piston rod, and lastly to contain the tool-holder d, 
 surrounded by two spiral springs in the space between the shoulder 
 />, and the cover s. The opening, o, allows the air to escape in 
 front of the piston-rod, and so makes the stroke easier ; I is the 
 exhaust port, and q a hole for lubricating ; r is the ring valve, 
 
 * En<j. Min. Jour., vol. Iv. (1893), p. 491. 
 
 t Johann Pilaf, " Schiammeissel, System Franke, im Mansfeldischen," 
 Ocst. Zdtschr. >.- u, II.- \V., vol. xl. (1892), p. 78. Suliradur, oj). cit. p. 171. 
 
2OO 
 
 ORE AND STONE-MINING. 
 FIG. 214. 
 
BREAKING GROUND. 201 
 
 sliding upon the piston, and as soon as it is drawn past the port 
 n, it is driven either forwards or backwards by the air pressure. 
 In the position shown in the figure, representing the end of 
 the return stroke, the valve r has been driven back, and the air 
 is enabled to pass from m into g, and so to the back of the piston. 
 The air in the space in front of the piston finds an exit along the 
 three passages h, of which only one can be shown in the section, 
 and entering the annular slide-valve, is brought by one of the 
 three radial passages, i, into the hollow central part j k of the 
 piston and piston-rod, and eventually to the exhaust I. As soon 
 as the piston, in its forward stroke, draws the valve r past the 
 port n. it is thrown over by the air pressure ; <?, through r, 
 now communicates with i, and the air passes from the rear end of 
 the piston to the exhaust ; at the same time the three passages 
 h are connected with the admission inlets of compressed air, and 
 the piston makes its return stroke. The piston is thus driven 
 backwards and forwards, striking a rapid succession of blows, 
 estimated at several thousand per minute, upon the back end of 
 the tool-holder d, and as fast as the latter is knocked forwards it is 
 drawn back by the action of the springs. The tool-holder is in no 
 way connected with the piston, and is quite free to turn round. 
 
 The length of the stroke of the chisel is only 0*06 to 0*08 inch 
 (1-5 to 2 mm.) As the annular slide-valve closes the ports n n in 
 passing, the air acts by expansion during the latter part of the 
 stroke. The air-pressure employed at Mansfeld is 60 Ibs. pei 
 square inch (4 atm.) 
 
 The chisel is made of J-inch round steel with an edge inch 
 wide; it is inserted in the strong socket of the tool-holder, and 
 the miner simply holds the cylinder so that the chisel presses 
 against the shale which he wishes to cut away (Fig. 205). It is 
 said that a man can undercut or ' ; hole " an area of 5 square feet 
 (0*5 sq. m.) per hour. Each hewer has to make a "holing" 
 about 10 feet (3 m.) long, and he carries it in to a depth of 20 
 inches to 2 feet from the face. The groove or " holing " is about 
 5^ inches (14 cm.) high at the face, and becomes lower and lower 
 as it goes in. 
 
 The men do not appear to suffer in any way from the vibrations 
 of the machine, which weighs only 10 Ibs. (4-5 kil.) including the 
 chisel. 
 
 (2) Travelling Rock Drills and Jumpers. A groove may 
 be made by boring a succession of holes immediately touching 
 each other, or separated by small partitions which are broken 
 down afterwards by a flat bit (broach). Most of the rock drill 
 companies supply special quarry-bars or frames, upon which an 
 ordinary boring machine can be mounted and made to travel, 
 and thus cut a groove along any required line. 
 
 With the IiKjersoll bar-channeller * a cutter is sometimes used 
 
 * EIUJ. Min. Juur., vol. xlix. (1890), p. 62. 
 
202 ORE AND STONE-MINING. 
 
 made of three chisels placed side by side, with their edges arranged 
 like the three strokes of the letter N, in the place of an ordinary 
 borer. As the carrying frame can be inclined, the groove can 
 be cut at an angle. 
 
 The Wardwell * stone channelling and quarrying machine may 
 be regarded as a mechanical jumper, cutting a vertical groove. 
 It is a portable 6 h.-p. engine with boiler, moving upon rails, 
 which is made to lift a set of boring chisels or cutters consisting 
 of five bars of square steel, clamped together in a line. The edges 
 of the centre and outside chisels are transverse, whilst the other 
 two are diagonal, and they are arranged in step fashion. Three 
 cutters only act at a time, viz. the centre cutter, arid either the 
 two in front or behind it, according as the machine is being 
 moved forwards or backwards. " The machine consumes 400 Ib. 
 of coal a day, and requires the services of three men. It will cut 
 from 75 to 150 square feet of channel in marble, and 150 to 400 
 square feet of limestone and sandstone in a day, which is 
 equivalent to the work of 50 men." 
 
 The Cleveland Stone Company, Ohio, employs no less than 
 thirty-nine of these machines in quarrying sandstone, with the 
 modification of having only three cutters instead of five. 
 
 The channelling machines of the Ingersoll and Sullivan Com- 
 panies running upon rails, either with or without a boiler, will 
 cut vertical or inclined grooves. 
 
 (3) Circular Saws. In alphabetical order the following may 
 be named : Crump and Brereton, Gillott and Copley, \Valker, 
 Winstanley. 
 
 Crump and Brereton s f machine is used for quarrying stone in 
 the United States. It will cut long vertical grooves 30 inches 
 deep and about inch wide. 
 
 It consists of a frame on wheels, moving upon rails, which 
 carries a small vertical boiler, steam-engine, circular saw about 
 5 feet in diameter, and the gearing necessary for driving it and 
 causing the whole carriage to advance as the cut is made. Tho 
 saw is a thin circular steel blade, about f inch thick with slots all 
 round the edge into which the teeth are inserted. They are 
 arranged so that they divide the narrow cut of | inch into 3 parts, 
 each tooth taking J inch. The teeth are sharpened by grinding. 
 The saw is driven from the periphery by a toothed wheel on each 
 side, the teeth of which gear into two circular sets of holes cut 
 near the circumference of the saw. It is caid that while making 
 a cut 30 inches deep in slate, it will progress at the rate of 
 4 inches a minute. 
 
 The Gillott and Copley % machine (Fig. 215) has been specially 
 
 * Eng. Min. Jour., vol. xlvii. (1889), p. 500. 
 f Engineering, vol. xli. (r886), pp. [54, 272. 
 
 G. B. Walker, " Coal-getting by Machinery," Proc. Fed. List. Min. Enrj., 
 vol. i. (1890), p. 128. 
 
BREAKING GROUND. 203 
 
 designed for cutting a more or less horizontal groove, under or in 
 a seam of coal, but it can also be applied to seams of other com- 
 paratively soft minerals. It is a cast-steel or malleable iron wheel 
 4 feet in diameter, armed with removable teeth, which are alter- 
 nately double and single. The groove which is cut is rather more 
 than 3 inches wide, and is big enough to allow the bracket sup- 
 porting the saw to enter it. Consequently, a cut can be made 
 nearly as deep as the diameter of the saw. 
 
 Just inside the circumference there is a circular rack into 
 which gears a bevel pinion driven by two compressed air engines 
 with cylinders 9 inches in diameter and having a Q-inch stroke. 
 The saw makes about 30 revolutions a minute. The two engines 
 are upon the carriage which supports the saw. The carriage runs 
 upon rails set at a gauge of i foot 7^ inches, and it draws itself 
 
 FIG. 215. 
 
 along by a wire rope, which has one end fixed at some convenient 
 point of the working face, and the other coiled upon a drum 
 attached to the carriage. The drum is made to revolve by a 
 pawl and ratchet-wheel worked by the engines, and there are 
 means of regulating the number of teeth taken by the pawl, 
 and in this way the advance of the machine. 
 
 Two men are required for working the machine ; the man 
 in front lays down the rails and sleepers, which are taken 
 up and passed to him by the man in the rear as soon as the 
 machine has gone over them. The whole machine is only i foot 
 9 inches above the rails ; its width, exclusive of the saw, is 3 feet 
 3 inches, and total length 9 feet; it weighs altogether 24 
 cwt. The makers state that it will undercut to a depth of 
 39 inches in hard coal or shale at the average rate of 12 yards 
 per hour, with an air pressure of about 30 Ibs. per square inch. 
 The saw cuts from back to front, and therefore clears out the 
 chippings that it makes. 
 
 The Rigg and Meiklejohn machine, which is in operation in 
 Scotland, is a circular saw of somewhat similar construction. 
 
 The cutting of a preliminary groove in some of the Cheshire 
 salt mines has long been done by Walker's circular saw (Fig. 216). 
 
 An improved form of the Winstanley saiv is doing good work at 
 
204 
 
 ORE AND STONE-MINING. 
 
 the Blanzy collieries. It is a circular saw 5 feet (1.50 m.) in 
 diameter, with 28 removable cutters, all of one shape, upon its 
 circumference. The cutters are arranged in fours, so that four of 
 
 S:Jw* 
 
 them cover the whole width of the holing, which is 3 inches 
 (7-6 cm.) high. Two small compressed air engines, inside the 
 waggon which carries the saw, drive a horizontal pinion, which 
 gears into the spaces between the cutters ; in fact, the saw is a cog 
 wheel with a cutter inserted into each tooth. The depth of the 
 holing is 4 feet. The total weight of the machine is 35 cwt. 
 (iSookil.) 
 
 (4) Endless chain with cutters attached. Baird's machine* 
 which is used both for coal and ironstone, is of this type. A 
 carriage moving on rails supports two cylinders worked by com- 
 pressed air, and these set in motion an endless chain with cutters, 
 which revolves round two pulleys, one at each end of a jib or arm. 
 The jib can be made to extend under the seam for a distance 
 varying from 2 feet 9 inches to 5 feet, and the groove which is 
 cut is only z\ inches high. 
 
 It is stated that a machine will make an undercut 2 feet 9 
 inches deep by 100 yards long in 8 or 10 hours. 
 
 (5) Wire Saw. The most novel method of cutting stone is 
 one which has been used at marble quarries in Belgium and eL-e- 
 where, and is called by the inventor the Helicoidal Saw System. 
 
 It consists in sawing grooves by an endless cord, composed of 
 three steel wires twisted together, which travels on the rock, and 
 is supplied with sand and water. The sand is drawn along by 
 the spaces between the wires, and will cut even very hard stone. 
 At present only vertical grooves have been cut ; the first process 
 consists in sinking two pits for receiving the pulleys which guide 
 the cord in making its cut, and which have to be lowered as the 
 cut is deepened. The pits are bored 2 feet 4 inches (700 mm.) in 
 diameter by cylinders of sheet-iron, with the lower and cutting 
 edge made of sheet- steel. The cylinder is made to rotate at the 
 
 * Walker, ibid. 
 
BREAKING GROUND. 
 
 205 
 
 rate of 100 to 180 revolutions a minute by a vertical axis set in 
 motion by a horizontal pulley at the top, driven by a wire rope, 
 whilst sand and water are fed in to the cutting edge. As the 
 annular groove is cut deeper and deeper, the cylinder is gradually 
 lowered by a little winch and two wire ropes. The cylinders now 
 in use are constructed so as to cut to a depth of 10 feet 9 inches 
 (3.30 m.). When this cut has been made, a core remains, which 
 can easily be broken off at the bottom and lifted out. In the 
 case of marble the core can be utilised and sold as a column. If 
 there is a demand for smaller columns, boring cylinders of less 
 diameter are used, and two or four holes are bored side by side. 
 After the removal of the columns the thin intervening partitions 
 of rock are broken down, and space enough is afforded for the in- 
 troduction of a pulley and a frame. 
 
 Two of these pulley-pits are prepared at the two extremities of 
 the line along which it is desired to make a saw-cut, which may 
 be 50 feet or more in length, if required, and the carriers are then 
 inserted. The carrier, made of channel iron, supports two 
 pulleys, each 2 feet in diameter ; one is fixed at the top, whilst 
 the second is so arranged that it can be lowered by a large screw. 
 
 The cord for sawing in the quarry is about J inch (6 mm.) in 
 diameter, made up of three wires of mild steel, twisted together so 
 
 FIG. 217 
 
 as to form a strand. It is driven at the rate of 13 feet (4m.) per 
 minute, and will deepen the cut in marble at the rate of 3 to 4 
 inches or more per hour. The friction of the spiral wires on the 
 pulleys and rock causes the cord to revolve a little as it is carried 
 forwards, and all parts of it are thus equally worn. When it is 
 so much worn that it no longer presents spiral spaces which will 
 
206 ORE AND STONE-MINING. 
 
 hold sand, it has to be changed. If it breaks while in use, it can 
 very easily be spliced. 
 
 Fig. 217 represents the arrangement adopted at the Traigneaux* 
 Quarry, near Philippeville, Belgium. A B C D E F is the wire 
 cord travelling in the direction shown by the arrows ; H and G 
 are the two pits which have been bored to hold the pulley-frames. 
 When the cutting process began, the wire cord would have been 
 running along the line I J ; the groove is gradually deepened 
 until at last it reaches the line K L. 
 
 When suitable vertical cuts have been made, the block is 
 severed horizontally by means of wedges. 
 
 (6) Revolving Bar with Cutters. Under this head maybe 
 classed the Bower, Lechner, and Legg machines, all of which have 
 been designed for holing coal. 
 
 Bower's machine consists of a bar 3^ feet long, armed with 
 steel teeth, which is made to revolve at the rate of 600 to 800 
 revolutions a minute by an electric motor. The bar rapidly cuts 
 away a groove as the motor is made to travel along the rails ; the 
 groove is 5 inches high in front, and 3 at the back.f 
 
 In the Lechner and Legg % machines the cutting bar lies parallel 
 to the line of the face, and not at right angles to it, as in Bower's 
 coal-cutter. 
 
 V. Machines for Excavating Complete Tunnels Hither- 
 to machines of this kind have been little used. Three may be 
 mentioned viz., the Beaumont, Brunton, and Stanley tunnellers. 
 
 The Beaumont machine has received a good deal of notice, 
 owing to its having been employed in the Channel Tunnel. It 
 consists of a very heavy horizontal iron shaft, which is made to 
 revolve by compressed air engines. The shaft carries a cross-head 
 armed with teeth, which cut away the whole face by a series of 
 concentric grooves. The chips are made to fall on to an endless 
 chain with buckets, and are thus conveyed to a waggon behind 
 the machine, so that no interruption of the work takes place for 
 loading. The machine travels forward in a cradle which fits the 
 bottom of the circular tunnel, and when the limit of advance is 
 reached, the machine is lifted up by screw-jacks, and the cradle 
 is once more brought under it, so that a new cut can be begun. 
 
 Like the Beaumont machine, Brunton' s tunneller excavates a 
 circular drift by chipping away the whole face, but in this case 
 the work is done by steel-cutting discs about 10 to 20 inches in 
 diameter, and from J inch to i inch thick. As yet it has been 
 little used. 
 
 * Copied from a pamphlet published by the /Societe anonyme Internationale 
 dufd heUqoidul. Brussels, 1888. 
 
 f G. B. Walker, " Coal-gettiug by Machinery," Proc. Fed. Imt. Min. Eng., 
 vol. i. p. 129. 
 
 % E>ig. Min. Jour., vol. xlvi. (Jane 1888), p. 399. 
 
 Jour. Soc. Arts, vol. xxii. (1873-74), p. 404. 
 
BREAKING GROUND. 
 
 207 
 
 Stanley's tunneller (Fig. 218), on the other hand, is a compara- 
 tively new machine already doing good work in driving headings 
 in coal. It consists in the main of a strong central shaft, which 
 carries a cross-head with two projecting arms. At the end of each 
 arm are three steel teeth or cutters. The central shaft is made to 
 revolve by a pair of small vertical compressed air-engines, and the 
 teeth cut away an annular groove 3 to 4^ inches wide. The chiy s 
 
 FIG. 218. 
 
 are brought out by scrapers attached to the arms which carry the 
 teeth. The advance of the cutters is caused by the forward 
 movement of the main central shaft ; this is screwed outside, and 
 works in a nut attached to the frame. The rate of advance 
 is therefore determined by the pitch of this screw and the speed 
 with which it is made to turn round. 
 
 After boring the annular groove to the depth of a foot or so, 
 large lumps of the central core break off, and the machine is 
 stopped to get them out. Work is then resumed till the arms 
 have penetrated to their full length. The machine is stopped, 
 the remaining part of the core is wedged out and cleared away, 
 and now the frame is run forward and fixed for another cut. 
 The rate of progress when working in coal is about i yard per 
 hour, and during a trial of 24 hours the machine cut a tunnel 
 64 feet 6 inches in length. The diameter of the headings or 
 tunnels is 5 feet. A machine for working in harder rock with a 
 slower cut is being tried. 
 
 Stanley has also made a modification of his tunneller in which 
 the whole of the face is cut into little pieces ; the chips are carried 
 off by an Archimedean screw and delivered into a waggon at t he 
 back. 
 
 MODES OP USING HOLES FOR BREAKING 
 GROUND. After holes have been bored, either by hand or by 
 machinery, a force of some kind has to be applied inside them in 
 order to produce a rending action. The commonest method is to 
 employ an explosive, but the treatment of the subject would not 
 
208 ORE AND STONE -MINING. 
 
 be complete without a brief mention of some other processes. 
 Holes may receive : 
 
 1. Wedges. 
 
 2. Water. 
 
 3. Wooden plugs. 
 
 4. Compressed air cartridges. 
 
 5. Hydraulic cartridges. 
 
 6. Lime cartridges. 
 
 7. Explosives. 
 
 I. Wedges. When a hole has been bored, a compound wedge 
 can be inserted which can do the work of splitting with far 
 greater ease than a single wedge driven into a mere crack in the 
 rock. The combination of three wedges is known as the plug and 
 feathers, a flat wedge, the plug, being inserted between the 
 feathers, which have the outer face curved. The feathers are 
 placed in the hole and the plug is driven down between them with 
 a hammer or sledge. 
 
 Varieties of this simple apparatus, in which the wedge or the 
 feathers are moved by hydraulic pressure or by a screw worked 
 
 FIG. 219. 
 
 by hand, have been used for getting down coal. Fig. 219 is the 
 Elliott multiple wedge of the Hardy Patent Pick Company. 
 
 2. Water. In cold climates the expansion of water in freezing 
 can be utilised for rending rocks in open quarries. A row of holes 
 is bored in the line along which it is wished to split off a block of 
 stone, the holes are filled with water and well stopped with wooden 
 plugs ; when the water is converted into ice, the block splits off. 
 
 3. Wooden Plugs. Dry oaken plugs are driven into holes and 
 then watered. The wood expands and causes a fracture. 
 
 4. Compressed Air. Air compressed to about 400 Ib. per 
 square inch has been employed experimentally in the place of gun- 
 powder for breaking down coal. 
 
 5. Hydraulic Cartridges. Levet proposes to use a flat 
 metallic tube placed in a borehole, which is rammed up tightly. 
 The flat metallic cartridge is then connected with an hydraulic 
 press, and as soon as this is worked the cartridge expands, and 
 the coal is broken off. 
 
 6. Lime Cartridges. This plan is mentioned with the two 
 last, not because it is employed in mines at the present time, but 
 simply to complete the series of methods of applying a rending 
 force in boreholes. 
 
 A small iron pipe is first placed in the borehole, which is 
 2f inches in diameter, and then a cartridge of compressed lime 
 
BREAKING GROUND. 209 
 
 with a groove to fit the pipe is inserted. The hole is now tamped 
 up, and water pumped into the pipe, saturating the charge. 
 Great heat is evolved, some of the water is converted into 
 steam, the lime expands, and large blocks of coal are broken oft". 
 
 7. Explosives. Thirty years ago gunpowder was practically 
 the only substance used for blasting at mines ; but nowadays the 
 number of explosives is great, and an exact classification is 
 necessary before they can be conveniently studied. 
 
 With the permission of Colonel Cundill, R.A., I borrow the 
 classification, as well as certain details, from his Dictionary of 
 Explosives * 
 
 1. Gunpowder ordinarily so-called. 
 
 2. Nitrate mixtures other than gunpowder. 
 
 3. Chlorate mixtures. 
 
 4. Nitro-compounds containing nitro-glycerine ; this includes the great 
 
 dynamite class. 
 
 5. Nitro-compounds, not containing nitro-glycerine (gun-cotton, &c.) 
 
 6. Explosives in which picric acid, or a picrate, is a main constituent. 
 
 7. Explosives of the Sprengel type. 
 
 8. Miscellaneous explosives. 
 
 (i) Gunpowder. Though gunpowder has lost much of its 
 former importance, owing to the greater strength of many of its 
 younger rivals, it is still largely employed for several reasons, viz., 
 its relative cheapness ; its slower action, which renders it more 
 suitable for blasting in certain soft rocks and for producing rents 
 without any violent smashing; and lastly, its freedom from 
 certain dangers which cling to some of the nitro-compounds. 
 
 The formula commonly given for gunpowder is: 75 parts of 
 saltpetre, 15 of carbon, and 10 of sulphur; but the powder 
 used for blasting in mines usually contains less saltpetre than 
 that which is employed for sporting or military purposes. 
 
 The following is an analysis of mining powder by Captain 
 Noble and Sir F. Abel : 
 
 Per cent. 
 
 Saltpetre 61-66 
 
 Potassium sulphate 0-12 
 
 Potassium chloride 0*14 
 
 Sulphur . .-' 15*06 
 
 Carbon , I7'93 
 
 Hydrogen. . . . .. . . 0-66 
 
 Oxygen . . . . . . . 2-23 
 
 Ash . . . . . . . 0*59 
 
 Water 1-61 
 
 loo-oo 
 
 The products of the explosion of gunpowder, according to the 
 same authors,f are by weight : 
 
 * Dictionary of Explosives, London, 1889, p. vii. 
 t " On Fired Gunpowder," Phil Trans. 1880, pp. 225, 278. 
 
 o 
 
210 
 
 ORE AND STONE-MINING. 
 
 
 Curtis & Harvey's 
 No. 6 Gunpowder. 
 
 Minlnsr 
 Powder. 
 
 Total solid products .... 
 Total gaseous products .... 
 Water 
 
 5774 
 41-09 
 1-17 
 
 47-04 
 
 51-35 
 1-61 
 
 100-00 
 
 ico-oo 
 
 The solid residue of the mining powder consisted mainly of 
 potassium carbonate, potassium monosulphide, and sulphur. 
 
 The percentage composition, by volume, of the gas produced 
 was : 
 
 
 Curtis & Harvey's 
 No. 6 Gunpowuer. 
 
 Mining 
 Powder. 
 
 Carbonic anhydride .... 
 
 50-22 
 7" <^2 
 
 32-I5 
 j-i- 75 
 
 Nitrogen . . .. 
 Sulphuretted hydrogen . . 
 
 / }* 
 34-46 
 2-08 
 2*4.6 
 
 Jj I 3 
 I9-03 
 
 7-10 
 
 2" 7"? 
 
 
 ^26 
 
 * / J 
 5"*A. 
 
 
 
 -4 
 
 
 100-00 
 
 100-00 
 
 The volume (calculated for a temperature of o C. and barometer 
 760 mm. of mercury) of permanent gases generated by the ex- 
 plosion of i gramme of dry powder is : 
 
 Curtis & Harvey's No. 6 
 Mining 
 
 . 241-0 cubic centimetres. 
 360-3 
 
 Mining powder is usually coarse-grained and highly-glazed, but 
 the workmen who adhere to the old plan of firing with straws 
 require a little fine-grained powder for filling them. In quarry- 
 ing and mining slate, a fine-grained gunpowder of very good 
 quality has been found by experience to answer best for rending 
 the rock evenly without smashing it. 
 
 Gunpowder is used either loose, or in cartridges made by the 
 men on the spot, or in cartridges supplied to them. Gunpowder 
 compressed into cylinders of diameters suitable for bore-holes, and 
 provided with a central hole for the insertion! of the fuse, has 
 lately been brought forward with some success ; but it has the 
 great disadvantage, shared with all hard cartridges, of not fitting 
 the bore-hole so closely as a pulverulent or plastic explosive. 
 
 (2) Nitrate Mixtures other than Gunpowder. As nitrate 
 of soda is very much cheaper than nitrate of potash, inventors have 
 
BREAKING GROUND. 211 
 
 naturally tried it as a substitute for the most expensive in- 
 gredient of gunpowder. The drawback of such explosives is that 
 they get damp, owing to the deliquescence of the nitrate of soda ; 
 and some of the so-called waterproof cases have been insufficient 
 in the humid climate of Great Britain to keep out the moisture 
 sufficiently. 
 
 (3) Chlorate Mixtures. Chlorate of potash is an unstable 
 salt, very sensitive to friction and percussion, and the explosives 
 made from it are so dangerous that only one, asphaline, has been 
 licensed in Great Britain. It was so light and bulky that it 
 never came into practical use. 
 
 Rack-a-rock is chlorate of potash soaked with " dead oil," a 
 dark heavy oil consisting chiefly of hydro-carbons, and derived 
 from coal tar, or with a mixture of equal volumes of dead-oil and 
 bisulphide of carbon, or with dinitro-benzole. The cartridges of 
 compressed chlorate of potash are dipped in the liquid when re- 
 quired for use ; the two ingredients, when separate, are not 
 explosive. 
 
 More than 100 tons of this explosive were used in the great 
 blast for removing the Hell Gate rocks in New York Harbour, 
 besides which large quantities had been consumed in making the 
 underground galleries. The variety employed at Hell Gate con- 
 sisted of 79 parts of finely-ground chlorate of potash, and 21 parts 
 of dinitro-benzole. 
 
 (4) Nitro-compounds containing Nitro-glycerine. Miners 
 are deriving immense benefits from explosives of this class which 
 includes dynamite and its congeners. 
 
 Nitro-glycerine or glyceryl nitrate is a light yellow oily liquid 
 with a specific gravity of 1-6, which freezes at about 40 F. 
 (4 C.), and explodes when heated to 360 F. (180 C.), or sub- 
 jected to a shock. 
 
 Its chemical composition is expressed by the formula 
 C 3 H 5 (N0 3 ) 3 , and it is prepared by the action of nitric acid upon 
 glycerine. It is extremely sensitive to shocks, and under the 
 action of a fulminating cap it explodes with great violence. It is 
 less sensitive to blows and detonation when frozen than in the 
 liquid state. 
 
 The results of its decomposition when perfectly exploded may 
 be represented by the following equation : 
 
 2C 3 H 5 (N0 3 ) 3 = 6C0 2 + 5 H 2 + N tf + O. 
 
 MM. Sarrau & Yieille * have communicated to the Academy 
 of Sciences the results of their researches concerning the decom- 
 position of certain explosives, among which is nitro-glycerine. The 
 
 * " Kecherches experimentales snr la decomposition rle quelqnes explosifs 
 en vas clos ; composition des gaz formes: " (Jomples liendtm, 1880, pp. 105* 
 and 1 1 12. 
 
212 
 
 ORE AND STONE MINING. 
 
 following table shows, in litres, the volume (at o C. and 760 mm. 
 of mercury) of each of the gases per kilogramme of the substance 
 exploded in a closed vessel. 
 
 Kind of Explosive. 
 
 CO 
 
 C0 2 
 
 II 
 
 N 
 
 
 
 C 2 n 4 
 
 H 2 S ; Total 
 
 Pure gun-cotton . 
 
 234 
 
 234 
 
 1 66 
 
 107 
 
 _ 
 
 _ 
 
 
 
 741 
 
 Gun-cotton and nitrate 
 
 
 
 
 
 
 
 
 
 of potash (50 percent. 
 
 
 
 
 
 
 
 
 
 each) . . V 
 
 
 
 171 
 
 
 
 109 
 
 45 
 
 
 
 
 
 325 
 
 Gun-cotton (40 per cent.) 
 
 
 
 
 
 
 
 
 
 and nitrate of am- 
 
 
 
 
 
 
 
 
 
 monia (60 per cent.) . 
 
 
 
 184 
 
 
 
 211 
 
 6 
 
 
 
 
 
 401 
 
 Nitro-glycerine 
 
 
 
 295 
 
 
 
 147 
 
 25 
 
 
 
 
 
 467 
 
 Ordinary blasting pow- 
 
 
 
 
 
 
 
 
 
 der . 
 
 64 
 
 150 
 
 4 
 
 65 
 
 
 
 4 
 
 17 
 
 304 
 
 If, however, the explosive is decomposed, at a pressure approach- 
 ing that of the atmosphere, by burning or imperfect detonation, 
 the volumes (again at o C. and 760 mm. of mercury) are very 
 different, as shown below : 
 
 Kind of Explosive. 
 
 N0 2 
 
 CO 
 
 C0 2 
 
 H 
 
 N 
 
 C 2 H 4 
 
 Total 
 
 Pure gun-cotton . 
 
 139 
 
 237 
 
 104 
 
 45 
 
 33 
 
 7 
 
 565 
 
 Gun-cotton and nitrate of 
 
 
 
 
 
 
 
 
 potash (50 per cent, of each) 
 
 7i 
 
 5* 
 
 S7 
 
 3 
 
 7 
 
 
 
 IQ6 
 
 Gun-cotton (40 per cent.) and 
 
 
 
 
 
 
 
 
 nitrate of ammonia (60 per 
 
 
 
 
 
 
 
 
 cent ) 
 
 122 
 
 65 
 
 10} 
 
 12 
 
 112 
 
 
 
 414 
 
 Nitro-glycerine 
 
 218 
 
 162 
 
 58 
 
 7 
 
 6 
 
 i 
 
 452 
 
 When these explosives are decomposed in this way, they liberate 
 nitric oxide and carbonic oxide, and the analyses of MM. Sarran 
 & Vieille confirm the practical experience of miners, who complain 
 greatly of noxious fumes, when, owing perhaps to a bad detonator, 
 a charge of dynamite or tonite fails to explode properly. 
 
 Nitro-glycerine was at first used alone, and was fired by a 
 small cartridge of gunpowder inserted into a strong paper case 
 eontaining the liquid ; this method soon gave way to the fulminat- 
 ing cap. Numerous accidents happened from the extreme sensi- 
 tiveness of the blasting oil to percussion, and these led to its being 
 given up in most countries. Nobel, who had introduced nitro- 
 glycerine, then invented a method of using the explosive with 
 comparative safety, by causing it to be absorbed by some porous 
 inexplosive substance. This was the original dynamite, but now 
 
BREAKING GROUND. 213 
 
 various mixtures of nitro-glycerine and other substances are made, 
 and we may place them all in the great dynamite class. 
 
 The dynamites may conveniently be arranged in two groups : 
 
 1. Dynamites with an inert base acting merely as an absorbent for the 
 liquid nitro-glycerine. Example : Ordinary dynamite. 
 
 2. Dynamites with an active, that is to say, an explosive or combustible 
 base. This explosive or combustible base may be charcoal, gunpowder or 
 other nitrate or chlorate mixtures, gun-cotton or other active compounds. 
 Examples : Blasting gelatine, Gelatine dynamite, Gelignite, Hercules 
 powder, Lithofracteur. 
 
 Dynamite was made originally by mixing 75 parts by weight of 
 thoroughly purified nitro-glycerine with 25 parts by weight of 
 infusorial earth, known as Kitselguhr, sufficiently absorbent in 
 quality when mixed in the above proportions to prevent exudation 
 of the blasting oil. 
 
 The British license for making dynamite now allows the 
 addition of a little carbonate of ammonium and the substitution of 
 carbonate of sodium, sulphate of barium, mica, talc, nitre, for a 
 portion of the Kieselguhr. 
 
 At ordinary temperatures dynamite is a plastic mass, gene- 
 rally somewhat reddish in colour, owing to a little ferruginous 
 matter in the infusorial earth. It freezes at about 40 F. (4 C ), 
 and when once frozen remains hard at higher temperatures than 
 40 F. 
 
 In the frozen state it is less sensitive to blows and detonation 
 than when plastic, but it is more susceptible to explosion when 
 set on fire. At some seasons in certain climates it has to be 
 thawed before being used. The natural warmth of some mines is 
 sufficient to soften it in the short interval between the time it is 
 taken below ground and the time it is required for use ; but it is 
 often necessary to resort to artificial thawing. A special pan is 
 supplied by the makers for this purpose. It consists of an outer 
 can filled with hot water, which encloses a receptacle for the 
 explosive. The outer can is surrounded by a bag of painted 
 canvas filled with a bad conductor of heat, so that the water 
 retains its warmth for a long time. The warming-pan cannot be 
 put on to a fire without the outer covering being burnt ; if proper 
 cans are supplied, the men are less likely to try the dangerous 
 experiments of warming dynamite in an old meat-tin over a candle, 
 or upon a shovel at the smith's forge, methods of thawing that 
 are not unknown. 
 
 The trouble of thawing, and the possibility of the operation 
 being performed in a dangerous manner by the miners, are 
 decided disadvantages to dynamite ; and these are not the only 
 ones. Its behaviour with water is a source of danger. If left in 
 contact with water, as happens sometimes when a hole misses fire, it 
 disintegrates ; the heavy oily nitro-glycerine separates, and finding 
 its way into cracks is liable to explode with violence fiorn the mere 
 
2i 4 ORE AND STONE-MINING. 
 
 concussion, when the rock is struck with the pick, borer, or sledge. 
 A fourth drawback lies in the fact that the whole of the charge 
 does not always go off ; portions may remain intact and then explode 
 unexpectedly from a blow, when work is resumed after blasting. 
 On the other hand, the plasticity of dynamite and some other, 
 nitro-glycerine explosives is a decided benefit, because the charge 
 can be pressed down so as to fit a hole which is not perfectly 
 cylindrical, or a cartridge can be squeezed flat and inserted into a 
 crack without boring any hole at all. Of course, the main advan- 
 tage of dynamite and its congeners over gunpowder is their 
 enoimous strength. 
 
 Atlas Powder. This is a lignine dynamite, consisting of wood- 
 pulp or sawdust, nitrate of sodium and nitro-glycerine. It is 
 manufactured in the United States. 
 
 blasting Gelatine. This powerful and favourite explosive is 
 made by mixing nitro-cotton (nitro-celliilose carefully washed and 
 purified) with nitro-glycerine heated to about 100 F (38 C.) 
 until enough nitro-cotton has been dissolved to convert the nitro- 
 glycerine into a jelly-like mass. The blasting gelatine in ordinary 
 use contains 93 to 95 per cent, of nitro-glycerine, the remainder 
 being nitro-cotton. In the plastic state it is less sensitive to a 
 shock or blow than dynamite, but when frozen the reverse is the 
 case. One great advantage which it possesses over ordinary 
 dynamite is that it is practically unaffected by water. That it 
 must be stronger than ordinary dynamite is evident at first sight, 
 because an active explosive is substituted for a wholly inert sub- 
 stance. T3ut there is the additional reason that the two explosives 
 mutually assist each other. The explosion of nitro-glycerine, as 
 we have seen, liberates free oxygen ; that of nitro-cotton liberates 
 carbonic oxide. In other words, the former explosive has more 
 oxygen than is necessary for complete combustion, the latter less. 
 The excess of oxygen of the nitro-glycerine makes up for the 
 want of it in the nitro-cotton. 
 
 Gelatine dynamite is a mixture of 80 per cent, of blasting gela- 
 tine with nitrate of potassium and wood meal. 
 
 Gelignite is a similar mixture containing only 60 per cent, of 
 blasting gelatine. 
 
 Giant powder is a term used in America for dynamite. The 
 Giant powder used in California consists of nitro-glycerine, nitrate 
 of sodium and wood-pulp or sawdust. Like Atlas powder it is 
 therefore a lignine dynamite. Several varieties are made con- 
 taining from 20 to 80 per cent, of nitro-glycerine. 
 
 In Hercules powder, also an American explosive, the nitro 
 glycerine is mixed with wood-pulp, carbonate of magnesium, and 
 nitrate of sodium, or with carbonate of magnesium, chlorate of 
 potassium, nitrate of potassium and white sugar. 
 
 Lithofracteur is no longer seen in England, though regularly 
 used in the Australian Colonies. 
 
BREAKING GROUND. 215 
 
 It may be looked upon as ordinary dynamite mixed with a 
 crude sort of gunpowder. 
 One analysis gave 
 
 Nitroglycerine 52 
 
 Kieselguhr 30 
 
 Powdered coal 12 
 
 Nitrate of soda 4 
 
 Sulphur . . .... . . 2 
 
 Other varieties of the explosive contain such ingredients as 
 charcoal, bran, sawdust, nitrate of barium, bicarbonate of sodium. 
 
 (5) Nitro- compounds not containing Nitro-glycerine. 
 The explosives of this class now in practical use are made from 
 the nitre-compounds : Nitro-cellulose, Nitro-benzole, or Nitro- 
 naphthalene. 
 
 Nitro-cellulose or gun-cotton is prepared by the action of a 
 mixture of nitric and sulphuric acids upon cotton. A mixture of 
 certain definite proportions and strength is used in order to secure 
 the special product required as a blasting agent. It lacks the 
 plasticity of dynamite and blasting gelatine, but it can claim the 
 advantage of never requiring to be thawed. It is made up into 
 cylindrical cartridges to suit bore-holes of various diameters, with 
 a central hole for the insertion of the fulminating cap or 
 detonator. Per se, gun-cotton is not largely used in mining. 
 When gun-cotton explodes properly its decomposition may be 
 represented by the following equation : 
 
 2(C 6 H 7 2 , 3 NO S ) = 9 CO + 3 C0 3 + 7 H.O + N r 
 
 One of the products of the explosion is the poisonous carbonic 
 oxide. This disadvantage can be counteracted by the addition of 
 a nitrate, and tonite is an explosive produced in this manner. It 
 is a mixture of gun-cotton and nitrate of barium, sold in cylin- 
 drical cartridges coated with paraffin to keep out the moisture. 
 By some miners it is preferred to dynamite for reasons of safety. 
 It does not freeze, and there is no danger of exudation of an ex- 
 plosive oil, when a charge which has missed fire has to be left in 
 a wet hole. 
 
 Ammonite is a mixture of nitrate of ammonium with mono- 
 nitro-naphthalene. Bellite is a mixture of nitrate of ammonium 
 with di- or tri-nitro- benzole. Roburite is essentially a mixture 
 of nitrate of ammonium with chlorinated di-nitro-benzole. It is 
 a yellowish-brown powder, and is sold in cartridges. Sometimes 
 there is also some chloro-ritro-naphthalene as an ingredient. 
 It is largely used in coal mining. Securite is an explosive of 
 similar composition. 
 
 (6) Picric Acid and Picrates. No explosives of this class 
 are in use in mines or quarries. 
 
 (7) Explosives of the Sprengel Type. Dr. Sprengel pre- 
 
2l6 
 
 OEE AND STONE-MINING. 
 
 pares explosives on the spot immediately before use, from 
 substances which by themselves are not explosive. He mixes a 
 combustible body with a highly oxidised body in such proportions 
 that the supply of oxygen shall produce complete combustion, and 
 he fires the mixture with a detonating cap. 
 
 Thus, for instance, nitro-benzole compounds are mixed with 
 ritrates of ammonium, potassium, or sodium. These could be 
 placed in Class 5. K-ack-a-rock, mentioned in Class 3, is an 
 explosive of the Sprengel type. 
 
 Dr. Sprengel's method cannot be employed in this country, 
 because it is not legal to manufacture explosives, even by mere 
 admixture of the ingredients, except in duly licensed factories. 
 
 (8) Miscellaneous Explosives. Fulminate of mercury, used 
 in making detonators, is the only explosive of this class which 
 requires any mention. Detonators are small copper cylinders, 
 closed at one end, containing a small quantity of fulminate of 
 mercury. They are made of various sizes to suit different 
 explosives. 
 
 Strength. The strength of explosives may be compared 
 by firing them in holes bored in leaden cylinders, and then 
 
 FIG. 220. 
 
 FIG. 222. 
 
 FIG. 223. 
 
 FIG. 224. 
 
 FIG. 225. 
 
 measuring the size of the cavity produced in each case. Fig. 
 220 shows a hole 6 inches deep bored in a strong block of 
 lead. The firing of 20 grammes (nj drachms) of gunpowder in 
 such a hole enlarged it but slightly (Fig. 221), whilst the dila- 
 tation caused in similar holes by firing like charges of dynamite 
 
BREAKING GROUND. 217 
 
 (Fig. 222), gelignite (Fig. 223), gelatine dynamite (Fig. 224), and 
 blasting gelatine (Fig. 225) illustrates the enormously greater 
 power of these nitre-glycerine explosives. 
 
 Charging and Firing. The commonest method of firing a 
 charge is by means of the safety fuse, a cord T ^- to J inch in 
 diameter, containing a core of gunpowder introduced during the 
 process of manufacture. Upwards of forty or fifty varieties are 
 made to suit the requirements of the miuer and the quarryman. 
 The cord is somewhat guarded against damp by tar, and, if more 
 protection is needed, the covering is increased in thickness, and 
 a layer of varnish is interposed. For wet ground the outer 
 part of the fuse is formed by one or two spiral coils of tape 
 or by gutta-percha. For blasting under water, the coat of gutta- 
 percha is often strengthened against injury by tape, or is doubled 
 or trebled. If still more care is necessary in order to secure an 
 absolutely impervious envelope, the fuse is made of lead tube, either 
 bare or protected in various ways. Special fuses are supplied for 
 export to warm countries. Fuse is usually sold in coils 24 feet in 
 length, but it can be obtained in longer coils for special purposes. 
 One or several white or coloured threads run down the centre 
 of the core of powder, and serve as trade-marks by which the 
 goods of different manufacturers can be recognised. They are 
 sometimes impregnated with nitrate of potassium, with the view 
 of carrying the fire along in case there should accidentally be a 
 slight interruption in the continuity of the core. Safety-fuse 
 burns at the rate of about two or three feet per minute, so it is 
 easy for the miner to secure ample time for retreat by taking a 
 sufficient length. Sometimes a fuse hangs fire, and many are the 
 accidents that have been caused by returning too speedily to a 
 hole on the supposition that the fuse had failed altogether. 
 " Hang- fires" may be due to damp, imperfection in manufacture, 
 or injuries before or after the fuse was put in the hole. Colonel 
 Majendie has shown that oil exercises a very retarding effect upon 
 the rate of burning of safety-fuse. 
 
 In blasting with gunpowder in the ordinary way, the charge is 
 put in either loose or enclosed in a paper bag, and it is pressed 
 down to the bottom of the hole with a wooden stick, whilst a 
 piece of fuse also is inserted, extending from the charge well 
 beyond the hole. If the powder is loose, the miner carefully 
 wipes down the sides of the hole with a wet swab-stick, or with a 
 wisp of hay twisted round the scraper, in order to remove any 
 loose grains adhering to the fuse or the sides of the hole, and then 
 presses in a wad of dry hay, moss, or paper. A little fine tamping, 
 often the dust from boring a dry hole, is now thrown in and 
 rammed down with the wooden charging-stick, and the same 
 process is repeated until an inch or two of tamping has been 
 introduced. The metal tamping-bar is now brought into opera- 
 tion, and the hole completely filled. If the hole is pointing 
 
2l8 
 
 ORE AND STONE-MINING. 
 
 upwards, the stuff for tamping has to be done up in little paper 
 cartridges, which are pushed up and then tightly rammed. 
 
 The hole is now ready for firing. As a rule the safety-fuse is 
 not ignited directly. In open quarries a piece of touch-paper is 
 attached to the end of the fuse, so that in burning it will 
 eventually light the gunpowder. In mines a candle-end (snuff) is 
 fixed under the fuse by a piece of clay ; it is lighted to see that 
 everything is all right and that it will burn properly, and then 
 blown out. The miner puts his tools out of the way of danger, 
 and after shouting " Fire " several times, sets light to the candle 
 and beats a retreat to some place where there is no fear of being 
 struck by the blast, and whence he can warn persons who might 
 otherwise walk into danger unawares. The candle burns through 
 the covering of the fuse, the fire reaches the core, and is soon 
 conveyed to the charge, which explodes -and does the necessary 
 work. 
 
 The old plan of firing, which is still in use in many places, 
 consists in inserting the needle into the charge and then tamping 
 up the hole. Care is taken to draw out the needle a little as the 
 tamping proceeds, so as to prevent too much force being required 
 for its final withdrawal. The small hole left in this way serves 
 for the insertion of a straw, rush, or series of small quills filled 
 
 FIG. 226. 
 
 FIG. 227. 
 
 FIG. 228. 
 
 with fine powder, which, like the fuse, reaches from the outside 
 to the charge. A short squib, which shoots a stream of sparks 
 down the needle-hole, is also used occasionally. The straw or 
 squib is lighted by some kind of slow match, made either by 
 dipping a cotton strand in melted sulphur, or soaking a piece <;f 
 paper or a wooden lucifer in the tallow of a candle ; touch-paper 
 is also used for the purpose. 
 
 Nitro-glycerine and nitro-cotton explosives are fired by the 
 detonation of a strong cap, which is a small copper cylinder closed 
 at one end, partly filled with a mixture of fulminate of mercury 
 and chlorate of potassium. The amount of the fulminate required 
 depends upon the explosive, and the makers supply detonators of 
 different degrees of strength. 
 
BREAKING GROUND. 
 
 219 
 
 The treble-strength detonators of the Nobel Company, supplied 
 for firing dynamite (Fig. 226), contain 0*54 gramme of the 
 mixture ; whilst the quintuple detonators, for blasting gelatine 
 (Fig. 227), have o'8 gramme, and the sextuple detonators i 
 gramme. 
 
 As full instructions for use are issued with every packet of the 
 nitro-glycerine explosives, it is not necessary to repeat them here. 
 
 Fig. 228 shows a hole charged with two cartridges of blasting 
 gelatine, a primer (i.e., a small cartridge) and cap, and afterwards 
 filled up with water as tamping. The fuse is turned back and 
 fixed by a lump of clay, and the little candle-end is placed in 
 position for lighting. 
 
 Pfeiffer and Wiehenkel * propose to make blasting with high 
 explosives safer and more efficient by interposing a column of 
 water between the charge and the primer. The concussion pro- 
 duced by firing a primer at the mouth of the hole is communicated 
 by the water to the charge, and is said to be sufficient to cause it 
 to explode. Of course the explosive used should be one not liable 
 to set free nitro-glycerine when in contact with water, as happens 
 with dynamite. 
 
 In a few mines where the straw still lingers in place of the 
 fuse, the detonator is squeezed on, and then gently inserted into 
 the hole left by the withdrawal of the needle. 
 
 The workman employed in getting slate frequently desires to 
 produce a rent without smashing the rock. He fills the hole, 
 
 FIG. 229. 
 
 FIG. 230. 
 
 possibly TO or 12 feet deep, almost up to the top, with a small- 
 grained gunpowder, and after ramming in a wad of dry moss and 
 an inch of tamping, sets light to the fuse in the usual way. 
 Provided his calculations are correct, the block is severed off 
 cleanly, and not broken up. 
 
 * German Patent Specification, No. 67,793, 1893. 
 
220 ORE AND STONE-MINING. 
 
 In quarrying sandstone, Knox* has found it advantageous to 
 leave an air-chamber above the charge of gunpowder in the 
 rifting holes (Fig. 229). A is the powder, B the air-space, and C the 
 tamping resting upon a wad of hay, grass, oakum, or paper. 
 
 For the purpose of firing several holes simultaneously, Messrs. 
 Bickford, Smith & Co., the original inventors of the safety-fuse, 
 have brought out a special arrangement, the action of which is 
 rendered plain by the Fig. 230. An ordinary fuse is fixed into a 
 metal case called the igniter, from which a number of instantaneous 
 fuses convey fire to as many separate holes. It is found in prac- 
 tice that this fuse answers very well. 
 
 In mines where the atmosphere may be inflammable from the 
 presence of fire-damp, the burning fuse may become a source 
 of danger, and a special igniter has been devised by Messrs. 
 Bickford, Smith & Co., to prevent accidents arising from this 
 cause. With the same object in view, frictional exploders have 
 been introduced, which ignite the charge when a string is pulled ; 
 but these belong more especially to the domain of coal-mining. 
 
 Charges may be readily fired singly or simultaneously with the 
 aid of electricity, either of high or low tension. Low-tension 
 fuses have the advantage that they can be tested with a weak 
 current and a galvanometer before use. If the galvanometer is 
 not deflected, it is evidpnt that the fuse is defective. 
 
 Fig. 231 shows a ^ecbion of one of Brain's high-tension fuses. A 
 is a cylindrical woodtn case containing a paper cartridge, B, with 
 
 FIG. 231. 
 
 an electric igniting composition, C, at the bottom. Two copper- 
 wires, D D, enclosed in gutta-percha, E E, reach down to the 
 composition, where they are about -fa inch apart. A copper cap 
 or detonator, G, is fixed on the small end of the wooden case. 
 The insulated wires, D D, are long enough to reach beyond the 
 bore-hole. The ends of the wires are scraped bare, and one wire 
 of the first hole is twisted together with one wire of the next 
 hole, and so on, and finally the two odd wires of the first and last 
 hole are connected to the two wires of a single cable, or to two 
 separate cables extend ing to some place of safety to which the men 
 can retreat. Here the two cable ends are connected by binding 
 screws to a frictional electrical machine or a dynamo exploder. 
 The electricity passes through the wires, making a spark at 
 
 * See p. 162. 
 
BREAKING GROUND. 
 
 221 
 
 FIGS. 232 & 233. 
 
 each break, and so firing the electiic igniting composition. The 
 flame flashes through the hole, H, and ignites the fulminating 
 mercury, the detonation of which causes the explosion of the 
 dynamite, blasting gelatine, or tonite surrounding the cap. 
 
 The fuses supplied by Nobel's Explosives Company are some- 
 what different. Their high-tension fuse (Fig 232) consists of a 
 copper cap, A, into which has been pressed a mixture of fulminate 
 of mercury and chlorate of potash, B ; 
 D D are two insulated wires, the ter- 
 minals of which are embedded in Abel's 
 flashing composition, F ; C is waterproof 
 cement, which serves to hold the wires in 
 position and to close the detonator. The 
 detonator and a few inches of the wire 
 are dipped in shellac varnish, so as to 
 make certain that no water can penetrate 
 during use. The current of electricity 
 produces a spark between the terminals, 
 ignites the flashing composition, and fires 
 the fulminate. 
 
 The low- tension fuse (Fig 233) differs 
 in having a thin bridge of platinum wire, 
 E, soldered across the terminals. This 
 bridge is embedded in a composition, F, 
 consisting of gunpowder and gun-cotton. 
 
 When the curreno of electricity passes through the bridge, it 
 heats the wires to redness, igniting the composition and firing the 
 fulminate as before. 
 
 Electric firing has the great advantage of enabling the miner 
 to retire to a perfectly safe place before attempting to explode the 
 charge. This is important in sinking shafts, where the means of 
 escape are less easy than in levels. A second advantage is the 
 absence of danger from a " hang-fire," an occasional source of 
 accident with the ordinary safety-fuse. On the other hand, in the 
 case of simultaneous blasting, it is impossible to be sure whether 
 all the holes have gone off properly, and electrical firing was given 
 up in driving a level in Saxony,* because unexploded dynamite 
 cartridges were so frequently found among the rubbish after 
 blasting. 
 
 DRIVING AND SINKING. We now come to the appli- 
 cation of the hand and machine tools in driving levels and 
 sinking shafts. 
 
 A level or drift is a more or less horizontal passage or tunnel, 
 whilst a shaft is a vertical or inclined pit. 
 
 In driving a level by hand labour in hard ground, the first 
 
 Dannenberg, Jakrb. f. d. Bercj- uni Iluttenwesen im K. Saclisen auf 
 Jahr 1890, p. 37. 
 
222 
 
 OHE AND STONE-MINING. 
 
 thing the miner has to do is to " take out a cut," i.e., blast out a 
 preliminary opening in the " end " or " forebreast." The position 
 of this first hole is determined by the joints, or natural planes 
 of division, which the miner studies carefully so as to obtain the 
 greatest advantage from them. 
 
 Thus Fig 234 shows a case in which, owing to joints, it was 
 advisable to begin with hole No. i, and then bore and 
 blast 2, 3, and 4, one after the other. The miner, as a rule, 
 does not plan the position of any hole until the previous one has 
 done its work ; in fact, he regulates the position and depth of 
 each hole according to the particular circumstances of the case. 
 
 In many of the drivages at the Festiniog slate mines there is 
 a well-marked inclined plane of separation, known as the " clay 
 slant," along which the level is carried. The first holes are 
 directed towards this " slant," and most of them are bored up- 
 wards; in this manner wedge-shaped pieces of slate are easily 
 blasted out, and subsequent holes are bored so as to increase the 
 
 FIG. 234. 
 
 size of this opening until the whole face of the "end" has 
 been taken away. 
 
 Though a vein and its walls may be hard, there is occasionally 
 a soft layer of clay (D D, D D, Fig. 235) along one wall (dig, 
 Cornwall; gouge, U.S.). The miner works this away with the 
 pick, and, after having excavated the groove as deep as possible, 
 blasts down the lode by side-holes, and so pushes the level for- 
 ward. 
 
 At St. Just, in Cornwall, a narrow groove is worked out by 
 a flat chisel called a peeker. 
 
 In sinking a shaft a similar method of proceeding is adopted. 
 A little pit (sink) is blasted out in the most convenient part, 
 and the excavation is widened to the full size by a succession 
 of blasts, each hole being planned according to circumstances 
 This series of operations is repeated, and the shaft is gradually 
 deepened. 
 
 Where boring machinery is employed, less attention and some- 
 times no attention is paid to natural joints, because, when once 
 
BREAKING GROUND. 
 
 223 
 
 the drill is in its place, it is very little trouble to bore a few 
 more holes, and the work can be carried on according to a 
 system which is certain of effecting the desired result. 
 
 A common mode of driving in hard ground is shown in 
 Figs. 236 and 237. Four centre holes are bored about a foot 
 
 FIG. 236. 
 
 FIG. 237. 
 
 
 FIG. 238. 
 
 
 <.*"* 
 
 apart at first, but converging till at a depth of 3 feet they are 
 within 6 inches or less of each other. 
 
 Other holes are then bored around them until the end is 
 pierced by twenty or thirty holes in all. The four centre holes 
 are charged and fired simultaneously, either by electricity or 
 by Bickford's instantaneous fuse, and the result is the removal 
 of a large core of rock. The holes round this preliminary 
 opening are then charged and fired, generally in volleys of several 
 holes at a time, and the level is thus carried forward a dis- 
 tance of 3 feet. If large holes are bored, 
 and if the ground is more favourable, 
 fewer will be required. 
 
 The Halkyn Drainage Tunnel (Flint- 
 shire) is being driven (7 feet high by 
 7 feet wide) in limestone by fourteen 
 holes for each advance ; they are started 
 with a 3^-inch bit, and finished with a 
 2j-inch bit. The holes are placed as 
 shown (Fig. 238), and are bored to a depth 
 of about 3 feet 9 inches each. They are 
 charged with dynamite, 25 Ibs. being 
 used for the fourteen holes, and then blasted in four volleys : 
 ist volley: Nos. i, 2, 3, and 4 together, which take out the 
 
 central core. 
 
 2nd volley: The side holes, 5, 6, 7, 8, are fired. 
 3rd volley: The top holes, 9, 10, u, are tired, the fuses being 
 
 arranged so that No. 10 goes off before Nos. 9 
 
 and u. 
 4th volley : The bottom holes, 12, 13, 14, the fuses being 
 
 arranged so that No. 1 3 goes off before Nos. 1 2 
 
 and 14. 
 
224 
 
 ORE AND STONE-MINING. 
 
 Roughly speaking, it takes five hours to bore the fourteen 
 holes, and five hours more to charge and blast them, and clear 
 away the rubbish. 
 
 Some engineers direct the four centre holes so that they 
 meet at the apex of an acute pyramid, and, after all have been 
 charged with dynamite, only one receives a primer and cap, 
 because the shock of the explosion of this charge is sufficient to 
 fire the other three adjacent charges simultaneously. 
 
 The preliminary opening is not necessarily made in the centre 
 of a level. Sometimes it is blasted out in the bottom or on one 
 side where there are natural joints to favour one of these methods ; 
 but when the rock is uniform it is best made in the centre, for 
 there the blasts can have the freest play. 
 
 At Bex, in Switzerland, where water power is abundant, a con- 
 siderable saving in cost has been effected by cutting a preliminary 
 groove in the centre line of the level by a bosseyeuse. 
 
 Seven holes, each 3^- inches (8 cm.) in diameter, are bored 2 
 inches (5 cm.) apart in a straight line, 
 FIG. 239. and the borer is then replaced by a 
 
 tool which breaks down the partitions. 
 A groove 2 feet 10 inches (86 cm.) 
 long and 3^ inch (8 cm.) wide is thus 
 formed, and after the bosseyeuse has 
 been removed, holes r2 inches (3 cm.) 
 in diameter are bored around by a 
 Ferroux drill as shown in the diagram, 
 Fig. 239. 
 
 The holes A, B, C, D, E, F, G, are 
 blasted at one time, but the fuses of 
 A and B are cut shorter than the 
 others, so that they go off 7 first. The 
 result of this volley is the produc- 
 tion of a large opening, and then the 
 firing of hole H, and subsequently of 
 
 the outside holes, completes the level for a length of 4 feet 
 (1-20 m.).* 
 
 In driving with the Ferroux drill in the ordinary 
 way, blasting out a central core, with dynamite, 
 the cost per metre of level driven was . . Fr. 73 40 
 By using the bosseyeuse to make a central groove, 
 and then the Ferroux drill for the remaining 
 holes, the cost per metre was only . . . Fr. 39 40 
 
 Saving effected by the use of the bosseyeuse . Fr. 34 oo 
 
 The saving therefore is as much as 46 per cent. ; but in this case 
 the extra water power required is costing nothing. 
 
 * Rosset. Notice sur les salines de Lex, Bex, 1888, p. 21- 
 
BREAKING GROUND. 
 
 225 
 
 In sinking shafts by boring machines, operations are con- 
 ducted much in the same way as in levels, save of course that the 
 holes are directed downwards. 
 
 Figs. 240 and 241 are a plan and a section of a shaft which was 
 sunk at the Foxdale mines in the Isle of Man. About forty-five 
 holes were bored in the bottom of the shaft before the drills were 
 removed. Two of the holes (A and B), and occasionally four, were 
 
 FIG. 240. 
 
 FIG. 241. 
 
 s^^^^^^^^^^ 
 
 bored only 4 feet deep, and were blasted with ordinary fuse. They 
 served simply to smash up and weaken the core ; then the six 
 holes nearest the centre, which were 8 feet deep, were blasted 
 all together with Bickford's instantaneous fuse, and the result 
 was the removal of a large core, leaving a deep sink. The re- 
 maining holes were fired in volleys of four at a time in the 
 ordinary way. In this manner the shaft, which was in hard 
 granite, was deepened at the rate of 3^ or 4 fathoms a month. 
 Tonite was the explosive used. 
 
 FIRE-SETTING. Though hard ground is almost invariably 
 nowadays attacked by boring and blasting, the very ancient pro- 
 cess of fire-setting is not quite obsolete. The effect of a fire is to 
 make a rock split and crack, and render it easily removable by 
 the pick or by wedges. 
 
 In 1876 I saw a level in course of being driven in the Kongsberg 
 silver mine, Norway, through crystalline schists, by this method. 
 A fire of logs of fir was made in the end, and the smoke was 
 conducted away to one of the shafts by an oval sheet- iron pipe, 
 2 feet by i foot. 
 
 It took eight cords of wood to drive i fathom of level, and the 
 rate of advance was 9 fathoms in 7 months. The fire was usually 
 made up twice in every 24 hours. In another part of the mine 
 an adit level was being driven at the rate of 2 fathoms a month, 
 with a consumption of 15 to 1 8 cords of wood. In this case an 
 arch was built in the roof of the level to form a passage for the 
 smoke, and the iron pipe was used near the end. 
 
 In driving in hard rock in the gold mines of Korea,* a pile of 
 
 * W. J. Pierce, "Gold Mining and Milling in Korea," Trans. A>n. Ins 1 ;. 
 M. E., vol. xviii., 1890, p. 363. 
 
226 ORE AND STONE-MINING. 
 
 wood is set on fire near the face of the tunnel, and allowed to 
 burn for 24 hours. The place is then allowed to cool for three or 
 four days, when the miners return and break down the loosened 
 rock with hammer and gad. Fire-setting is also employed in 
 mining jade in Burmah,* and in quarrying stone in India.f Lastly, 
 the Siberian prospector avails himself of the softening action of 
 fire for sinking small trial shafts through ice arid frozen ground 
 in search of auriferous gravel. 
 
 EXCAVATING BY WATER. We turn naturally from 
 fire, one of the four elements of the ancients, to another, water, 
 as a means of breaking ground. 
 
 Water can be applied either for dissolving the rock or mineral, 
 or for loosening it and then carrying it away. 
 
 There are two cases in which water may act as a solvent viz., 
 common salt and copper. It is used, as we shall see in speaking 
 of the methods of working, to dissolve out salt from saliferous 
 rocks, and it can also be employed for excavating upwards or 
 downwards in rock-salt. For excavating upwards (" putting up 
 a rise"), a jet of water is made to play upon the roof of a level, 
 and means are taken to carry off the brine in troughs (launders) 
 without dissolving away the floor. For sinking from one level to 
 another, a bore-hole is first put down, and this is gradually 
 widened by the solvent action of water. 
 
 When old workings containing the sulphides of copper are left 
 exposed to the action of air and the percolation of rain water, 
 part of the copper becomes converted into a soluble sulphate, and 
 water pumped up from the mine may become a profitable source 
 of the metal. This is the case at Parys mine in Anglesey. 
 
 There are also two cases in which water is made to act as a 
 loosener and conveyer viz., for working clay and gold. 
 
 A stream of water is turned on to the deposits of china clay, 
 and, aided by work with a pick, it carries everything to settling 
 pits. The most important application of water is the process of 
 washing away thick beds of auriferous gravel, known as hydraulic 
 mining. A huge jet of water under pressure is made to play 
 against the bank of gravel, undermine it, cause it to fall, and so 
 thoroughly disintegrate it that everything save the largest 
 boulders is carried away in the stream. Full details of these pro- 
 cesses will be given in Chapter VI. (Exploitation). 
 
 * Eng. Min. Journ., vol. xlviii., 1889, p. 359. 
 t Ibid., p. 547. 
 
CHAPTER V. 
 SUPPORTING EXCAVATIONS. 
 
 Various kinds of timber used for supports. Preservation of timber from 
 dry rot. Tools. Timbering levels, shafts, and working places. 
 Masonry, brickwork and concrete for levels and shafts. Iron and 
 steel supports for levels, shafts, and working places. Special pro- 
 cesses for sinking through watery strata : boring, compressed air and 
 freezing methods. 
 
 EXCAVATIONS made in hard ground will frequently stand with- 
 out any props whatever for an unlimited time, but the miner 
 has generally to deal with rocks which sooner or later give way 
 unless supported. Consequently it becomes necessary to adopt 
 means of securing the underground passages and working places, 
 either during the process of excavation, or at all events very 
 soon afterwards. 
 
 The methods of securing mining excavations may be classified 
 according to the materials used for the protective lining, viz., 
 timber, masonry, iron, or steel. 
 
 TIMBER. In Europe, varieties of the following kinds of 
 trees are those most frequently employed underground : Oak, 
 larch, pine, fir, and acacia. 
 
 The oak is especially adapted for mining purposes on account 
 of its strength and its durability. It will resist alternate 
 exposure to wet and dryness, and under water it is almost im- 
 perishable. In England we have two principal varieties, Quercus 
 robur pedunculata and Quercus robur sessiliflora. 
 
 The conifers, larch, pine, and fir, have the advantage of 
 furnishing straight timber, of even grain, comparatively light, 
 easily worked, having few branches, and less expensive than oak. 
 
 The larch (Abies larix or Larix Europcea, D. C.) is an excellent 
 mining timber. The large amount of resin it contains seems to 
 act as a preventive against decay. It is tough and strong, and 
 lasts a long time, even when alternately wet and dry. 
 
 The American pitch pine (Pinus rigida) is a timber largely 
 imported into this country for mining purposes, and it is used 
 not only for securing shafts and levels, but also for pump-rods, 
 bridges, sides of ladders, &c. It is remarkable for its perfectly 
 straight growth ; it is hard, highly resinous, and very durable. 
 
228 ORE AND STONE MINING. 
 
 The Scotch fir ( Pinus sylvestris) is a tree that furnishes a great 
 deal of mining timber. The British -grown timber is largely 
 used for props, whilst balks imported from Norway and Sweden 
 serve for heavy work in many mining districts. 
 
 The spruce fir (Abies excelsa) is not a timber to be recom- 
 mended for mine supports where durability is required. 
 
 The acacia has the property of resisting the effects of bad air 
 and high temperatures very much better even than oak. 
 
 Mr. Fernow* gives the following list of the various kinds of 
 mining timber which are available in the United States, eacli 
 series being arranged in order of durability, beginning with the 
 trees most adapted to resist decay. 
 
 EASTERN RANGE. 
 
 Conifers. Red cedar (Juniperus Virginiana, L.) ; White cedar ( Chamcecy- 
 paris sphazroidea, Spach.) ; Arbor vitse (Thuya occidentalis, L.) ; Bald 
 cypress (Taxodium distichum, Rich); Long-leaved pine ( Pinus palustris, 
 Miller) ; Red pine (Pinus resinosa, Ait.) ; Cuban pine (Pinus Cubensis, 
 Griseb.) ; Short-leaved pine (Pinus mitis, Michx.). 
 
 Broad-leaved trees. White oak (Quercus alba, L.) ; Post oak (Quercus 
 oltusiloba, Michx.) ; Chestnut oak (Quercus prinus, L ); Live oak (Quercus 
 virens, Ait.); Basket oak (Quercus Michauxii, Nutt.) ; Burr oak (Quercus 
 macrocarpa, Michx.); Osage orange (Madura aurantica, Nutt.); Hardy 
 catalpa (Catalpa speciosa, Warder); Black locust (Bobinia pseudacacia, 
 L.) ; Honey locust (Gleditsclda triacanthos, L.); Red mulberry (Morusrubra, 
 L.); Chestnut (Castanea vulgaris, var. Americana, A.D.C.) 
 
 ROCKY MOUNTAIN REGION. 
 
 Red cedar (Juniperus Virginiana, L.) ; Pinyon pine (Pinus edulis, 
 
 Fngelm.) : Foxtail pine (Pinus Balfouriana, Murray); Douglas spruce 
 
 (Pseudotsvga Douglasii, Carr. ); Western larch (Larix occidentalis, Nutt.): 
 Burr oak (Quercus macrocarpa, Michx.) 
 
 PACIFIC SLOPE. 
 
 Yew (Taxus brevifolia, Nutt.); Redwood (Sequoia sempervirens, End- 
 licher); Lawson's cypress ( C hamrecyparis Lawsoniana, Parl.) ; Canoe 
 cedar (Thuya gigantea, Nutt.); Douglas spruce (Pseuc/otsnga Douglasii, 
 Carr.); Western larch (Larix occidental, Nutt.); Live oak (Quercus 
 clirysokpis, Liebm.) ; Post oak (Quercus Garryana, foougl.). 
 
 The Douglas spruce, or Oregon fir or pine, is not only 
 used in America, but also exported to Australia. It is a very 
 straight wood, of even grain ; it has the disadvantage of easily 
 taking fire. 
 
 In Australia, the native woods are commonly used for mining 
 purposes, and among them different species of Eucalyptus are 
 specially prominent. 
 
 The Jarrah (Eucalyptus marginata) is a native of Western 
 
 * " The Mining Industry in its Relations to Forestry," Trans. Am. List. 
 M.E., vol. xvii., 1888, p. 264. 
 
SUPPORTING EXCAVATIONS. 229 
 
 Australia. It gives a red, heavy, intensely hard wood, which is 
 difficult to work with ordinary tools. It resists decay in a re- 
 markable manner, in fact it is practically indestructible ; the white 
 ant and the " teredo navalis " will not attack it. Up to the present 
 time there has been little need of mining timber in the colony of 
 which it is a native ; but it is exported to South Australia and 
 New South Wales, and used for shaft-frames and other special 
 purposes. 
 
 The grey or white iron-bark (Eucalyptus crelra, F. v. M.), 
 and the red or black iron-bark (Eucalyptus leucoxylon, F. v. M.), 
 both give hard, heavy, strong, and durable timber, and are among 
 the most useful of the forest trees in Australia. 
 
 Grey box (Eucalyptus largiflorens) is a hard, tough, durable 
 wood which lasts well underground. The young trees supply 
 much prop timber in certain localities. 
 
 Stringy bark (Eucalyptus obliqua), possesses similar good 
 qualities ; and it is imported into Australia from Tasmania if 
 the supply of the native-grown timber is insufficient or less easily 
 obtainable. It is employed as sawn timber, or split, and the 
 small trees make excellent props. 
 
 Among other species of Eucalyptus may be mentioned the 
 slaty gum (E. bicolor, A. Cunn.), and bloodwood, (E. corymbosa, 
 Sm.), both strong and durable and used for railway sleepers. 
 
 The prickly leaved tea-tree (Melaleuca armillaris) gives a 
 hard, strong, heavy timber, lasting well underground. 
 
 New Zealand can boast of the magnificent Kauri pine 
 (Dammara Australia), a slow-growing tree, some living examples 
 being estimated to be 2000 years old.* It contains a fluid resiii 
 which oozes out from every part, and hardens into large masses 
 of opaque gum. It is light, elastic, even-grained and strong. 
 Besides being used for timbering mines in New Zealand, it is 
 exported to Australia for the same purpose. 
 
 Matai (Podocarpus ferruyinea), a reddish-brown, moderately 
 hard wood, Miro (Podocarpus spicata), and Rewarevva (Knightia 
 excdsa) may also Le mentioned among the New Zealand mining 
 timbers. 
 
 In Japan the levels are sometimes timbered with bamboo. 
 
 Preservation of Timber. Most authorities consider that the 
 best time for felling timber is winter, when the wood has the least 
 amount of sap in it, because fermentation of the sap is one great 
 cause of decay. For this reason also, timber should be seasoned 
 before it is used; that is to say, it should be allowed to dry gradually 
 and so lose the sap by evaporation. Fernowf says that proper 
 seasoning is more important than the time of felling. As regards 
 
 * Laslett, Timber and Timber Trees, London, 1875, P- 2 9^- 
 t Op. cit. and " Relation of Railroads to Forest Supplies and Forestry." 
 Bulletin No. i, Forestry Division, Department of Agriculture } U.S.A. Wash- 
 ington, 1887, pp. 37 and 67. 
 
230 ORE AND STONE-MINING. 
 
 the removal of the bark or not, there is a difference of opinion, 
 but it certainly facilitates the seasoning ; and in the case of oak 
 the bark may be taken off for sale by the owner of the plantations, 
 before he disposes of the timber to the miner. On the whole it 
 seems advisable to remove the bark, and for two reasons ( i ) less 
 liability to rot, and (2) earlier indications of incipient crushing, 
 
 When stored at the mine, timber is best preserved under cover, 
 protected from wind and weather, but with ample access of air ; 
 and it is important to remove all decaying wood, whether logs, 
 chips, or sawdust, and destroy it by fire, so as to prevent the 
 spread of the contagion. The timber should lie upon supports 
 and not directly on the ground, and the pieces should not be 
 placed too close together. 
 
 According to Laslett,* "the approximate time required for 
 seasoning timber under cover, and protected from wind and 
 weather, is as follows : 
 
 Oak. Fir. 
 
 Pieces 16 to 12 inches square 14 months. 7 months. 
 
 ., 12 to 8 10 5 
 
 8 to 4 6 3 
 
 Planks, from one-half to two-thirds the above time according 
 to thickness." 
 
 Timber is often found to decay very rapidly in some mines, or 
 in certain parts of a mine, owing to the spread of what is called 
 dry rot. This is a white fungus which grows over the timber, 
 and causes the woody fibre to decompose and become so soft and 
 rotten that a knife or pick can be run in with the greatest ease. 
 
 Various methods of preventing dry rot have been tried with 
 more or less success. Good ventilation is all-important, for 
 timber is found to become affected most rapidly in places where 
 the air is foul or stagnant. Water has a decided preservative 
 effect, so much so that arrangements are sometimes made for 
 causing it to tiickle down continuously over the timber in a 
 shaft, or to form a spray in timbered levels. Probably the water 
 acts by washing off the spores of the fungus as fast as they are 
 deposited upon the timber, and also by cleansing the atmosphere 
 and keeping it cool. 
 
 Mine timber is also occasionally treated with antiseptics, such as 
 brine (with or without chloride of magnesium), borax, creosote, 
 carbolineum, coal-tar, corrosive sublimate, chloride of zinc, sul- 
 phate of zinc, sulphate of copper and sulphate of iron ; but far less 
 attention has been given to this subject by mining than by civil 
 engineers, to whom the duration of railway sleepers (ties, U.S.A.) 
 is a matter of much importance. 
 
 Treatment with a metallic salt is preferred to creoscting, if 
 the timber is at all exposed to the risk of catching fire. 
 
 * Op cit. p. 316. 
 
SUPPORTING EXCAVATIONS. 231 
 
 The timber is treated in one of the following ways : 
 
 (1) Steeping. The timber is simply placed in the preservation solution, 
 and allowed, tu absorb what it can. 
 
 (2) Hydrostatic Process. The preservative solution is forced in by 
 hydrostatic pressure. 
 
 (3) Vacuum Process. The timber is placed in boilers, and steam is 
 admitted ; the air and vapours are then exhausted, and a preservative 
 turned in under pressure. 
 
 (4) Painting, i.e., application with a brush. 
 
 It was found by experiments carried on at Commentry during 
 a long series of years, that one of the best methods was soaking the 
 timber for twenty-four hours in a strong solution of sulphate of 
 iron (green vitriol). The total cost was only Jd. per yard of prop, 
 whilst the timber lasted eleven times as long as when this simple 
 treatment was omitted. " Carbolineum " is a patent preparation 
 laid on with a brush like paint, which is well spoken of by the 
 mining officials at Saarbriicken.* The cost of two coats of the 
 preservative material on a prop 8 feet long by 10 inches in 
 diameter (2-5 m. by 25 cm.) is about 7|d. 
 
 The duration of a prop, or other piece of timber, is not the 
 only point to be considered in deciding whether it is worth while 
 paying the cost of some preservative treatment. The expense of 
 the labour in the renewal of unsound timber, such as the cutting 
 of fresh hitches, must not be overlooked. 
 
 Tools. Timber is used in various forms either whole and 
 merely sawn into lengths, or hewn or sawn into square balks, or 
 sawn in half, or sawn or split into planks of different thicknesses. 
 
 The tools used by the miner for shaping the timber are the 
 saw and axe ; in addition he requires a measuring staff, a sledge 
 or a wooden mallet for driving the timber into its place, a hammer 
 and "moil" for chipping out recesses or niches (hitches), plumb 
 line and level. 
 
 The saws vary in different countries. In Great Britain the 
 tirnberman's saw is the ordinary hand-saw of the carpenter, 
 though a cross-cut saw worked by two men is used for cutting 
 large props or balks. In the Hartz the timberman uses a saw 
 somewhat resembling our cross-cut saw in shape, but smaller in 
 size, and having the toothed edge curved, whilst in Saxony a 
 frame saw is preferred. All large mines have a circular saw, and 
 some are provided with special machines for cutting the joints of 
 supporting frames. 
 
 The axe varies in shape more according to the fancy of the user 
 than any special difference in the purpose for which it is used. 
 
 The moil is merely a pointed steel bar. In order to ascertain 
 the length required for a piece of timber to n't a given place, the 
 timberman uses a measuring staff, consisting of two bars of wood 
 
 * Zedsclif.f. B.- H. u. S.-Wesen, vol. xxxviii., 1890, p. 265. 
 
232 
 
 ORE AND STONE-MINING. 
 
 which are made to slide upon each other, and then fixed in any 
 position by a thumb-screw. One end is often rounded so that it 
 may reach to the bottom of the niche (hitch) which has been cut 
 in the rock. The plumb line and level need no description. 
 
 The principal kinds of excavations in mines are levels, shafts, 
 and ordinary working places. These will be taken in order, and 
 the methods of securing them dealt with briefly. 
 
 Levels. Though a level is an excavation of a very simple 
 nature, the methods of timbering it vary considerably, because 
 the parts requiring support may either be the roof alone, or the 
 roof and one or two sides, or the roof, sides, and bottom. 
 
 If the roof only is weak, as is the case with a soft lode between 
 two hard walls, a cap with a few boards resting on it (Fig. 242) 
 
 FIG. 242. 
 
 is sufficient to prevent falls. If one side is weak the cap must 
 be supported by a side prop or leg (Fig. 243), and very often by 
 two legs. The form of joint between cap and leg are numerous 
 (Fig. 244), depending to a great extent on the nature of the 
 
 FIQ. 
 
 FIG. 246. 
 
 pressure, whether coming upon the top or sides, and also on the 
 shape of the timber, whether round or square. With round 
 timber the top of the leg may be hollowed out as shown in 
 Fig. 245 A; but occasionally the joint is flat, and a thick nail 
 or nog is put (Fig. 245 u) to prevent the effects of side pressure, 
 
SUPPORTING EXCAVATIONS. 
 
 233 
 
 or, better, a piece of thick plank is nailed under the cap 
 (Fig. 246). 
 
 Where the floor of a level is soft and weak, a sole-piece or sill 
 becomes necessary, and if the sides or roof are likely to fall in, a 
 
 FIG. 247. 
 
 CAP 
 
 FIG. 248. 
 
 SOLE PIECE 
 
 lining of planks or poles is used (Fig. 246). "Horned sets" 
 (Fig. 247)* are useful in loose ground. 
 
 Fig. 248 shows the special system adopted on the Comstock lodef 
 for some very heavy ground. The outer planks (lagging) are put 
 close together, and the method 
 of jointing has been carefully de- FIG. 249. 
 
 signed so as to prevent any yield- 
 ing under the enormous pressure 
 to which it is subjected. These 
 levels are 6 feet high inside the 
 timber. 
 
 As an instance of timbering on 
 a much larger scale, I give a re- 
 presentation of the supports at 
 Ilio Tinto, Spain (Fig. 249 ); the 
 height of the level from the 
 groundsill (a) to the cap (c) is 12 
 feet 7 inches (3 -85 m.), so as to 
 allow the passage of locomotives. 
 
 In driving levels for the deep 
 gold-bearing gravels in the Cari- 
 boo district, B.C.,| spruce fir i to 2 
 barked, is used for making the sets. 
 
 feet in diameter, simply 
 The lagging is in pieces 
 
 * Rep. Insp. Mines, Victoria, for 
 t Hague, ' Mining Industry," Unite 
 
 p. 7. Melbourne, 1876. 
 States Geological Exploration of the 
 
 Fortieth Parallel, vol. iii., plate iv., p. 113. Washington, 1870. 
 Dawson, " General Note on the Mines and Minerals of Economic Value 
 
234 
 
 ORE AND STONE-MINING. 
 
 4 feet long, 5 inches wide, and 2 inches thick, and is split out of logs. 
 The ground is so heavy that the frames (sets) are only a few inches 
 apart in some places. Where the ground is very wet, spruce brush- 
 wood is placed behind the lagging. 
 
 In the Day Dawn mines in Queensland,* the gold vein some- 
 times attains a width of 60 feet ; the hanging wall is not strong, 
 and large portions of the lode itself are apt to slip away. 
 
 FIG. 250. 
 
 6 7 METP.E? 
 
 Though the levels could be driven without diGculty, it was found 
 impossible, with the ordinary methods of timbering, to keep them 
 open permanently after the vein had been worked away, and the 
 whole pressure of the heavy ground on the hanging wall had to 
 be supported. At last the so-called "pigsty" method was tried, 
 and it has been found very successful. It consists in piling up 
 logs 4 to 8 feet long, two by two, crosswise, and so building a 
 support which covers a comparatively large area. 
 
 Pigs. 250 and 251 represent the pigsty timbering; the former is 
 
 of Briti-h Columbia," GPO!. Survey, Canada. Keprinted from Canadian 
 Pacific Jiailtray Report, 1877, p. 8. 
 
 * This description and the figures have been kindly supplied by Mr. 
 Joseph Shakeupcar, one of the Government Inspectors of Mines in Queens- 
 land. 
 
SUPPORTING EXCAVATIONS. 235 
 
 a section along the line of dip, the latter along the line of strike. 
 As the drivage progresses, strong sills, loto 12 inches in diameter, 
 are laid along the floor of the level. These sills may be as much 
 as 25 feet in length, and two of them are laid under each row of 
 sties, which are placed about 6 or 8 ft. apart in the direction 
 of the level. The number across the level depends upon the 
 width of the lode, and the spaces between the rows of pigsties 
 form the roads for the waggons. The cap-pieces are made of 
 
 FIG. 251. 
 
 
 
 -^^^^^iri^- ^52^"^S^ 
 SCALE 
 
 10 5 10 IS 20 25 FEET 
 
 IMETRE I 2 3 A 5 S 7 METRES 
 
 timber 15 inches in diameter, and they rest upon the pigsties. 
 Upon the cap-pieces comes a row of poles, which support the 
 deads when the lode is worked away above. 
 
 Where the width of the lode is not too great, the sills are dis 
 pensed with ; the ground at the bottom of the level behind the 
 end is excavated, and the pigsties are built up from the foot- 
 wall. Consequently, when the lode is removed by the workings 
 below, the level is not affected because the timbering is supported 
 from the undisturbed footwall. 
 
 When sills are used in a very wide lode, pigsties resting upon 
 the footwall are built up whilst the ore is being excavated, and 
 they are arranged so as to come exactly under the sills and carry 
 their weight. 
 
 This method of support requires a great deal of timber, but 
 it has the advantage that the small logs used for the pigsties are 
 inexpensive and easily handled, compared with huge balks 
 required with the other systems. 
 
236 ORE AND STONE-MINING. 
 
 If the ground is loose so that the roof or sides, or both, will run 
 in unless supported, the method of working called spilling, spiling, 
 or poling is pursued. It consists in supporting the weak parts by 
 boards or poles in advance of the last frame set up. The process 
 may be described as pushing out a protecting shield in very 
 narrow sections, one at a time. The poles or boards (laths) are 
 driven forward by blows from a sledge, and the ground is then 
 worked away with the pick ; this removal of ground enables the 
 laths to be driven in further ; the pick is now once more called 
 into requisition, and by successive small advances the shield of 
 poles or boards is extended a distance of 3 or 4 feet. Fig. 252 
 shows one of the advance poles partly driven, with the front end 
 
 FIG. 253. 
 
 resting upon a set of timber ; the pole behind it is in its final 
 position. The section, Fig. 253, explains that the lower set of 
 poles, those which are in the course of being driven, have room 
 enough to slide on top of the cap, owing to the blocks placed 
 upon it being slightly thicker than their diameter. 
 
 In running ground it is necessary to have the laths fitting 
 closely together, and the working face must also be supported by 
 breast-boards, kept in place by little struts resting against the 
 nearest frame. These are removed and advanced one by one, 
 after the laths in the roof, sides and bottom have been driven 
 beyond them. 
 
 In a few instances the end of a level in running ground has 
 been kept up by covering the entire working face with wooden 
 wedges; an advance was gradually effected by driving them in 
 with a heavy sledge. The sides and top of the level were pro- 
 tected by laths in the ordinary way. 
 
 Shafts. The timbering required for shafts varies according to. 
 the nature of the ground and the size of the excavation. A mere 
 lining of planks set on their edges (Fig. 254) suffices for small 
 shafts, corner-pieces being nailed on so as to keep the successive 
 frames together. 
 
 The usual method of securing shafts is by sets or frames. Each 
 set consists of four pieces two longer ones called wall plates, and 
 
SUPPORTING EXCAVATIONS. 
 
 237 
 
 two shorter ones called end pieces. They are joined by simply 
 halving the timber at each end, as shown in Fig. 255, the wall- 
 plate being made to rest upon the end-piece, though this arrange- 
 ment is sometimes reversed. A more complicated joint (Fig. 256) 
 is often preferred. The separate frames are kept apart by distance 
 
 FIG. 254. 
 
 FIG. 255. 
 
 FIG. 256. 
 
 pieces (studdlfis, Cornwall; jogs, Flintshire; posts, U.S.), and 
 loose ground is prevented from falling in by boards or poles 
 outside. The length of the distance pieces must depend upon 
 the solidity of the ground. If the ground is very weak they are 
 not used at all, and the successive frames are put in touching each 
 other; in loose ground near the surface the distance between 
 the frames may be 18 inches, for instance, and then increased 
 gradually to 4 or 5 feet when the shaft has penetrated into harder 
 strata. 
 
 The end-pieces are sometimes made long enough to project a 
 foot or eighteen inches beyond the wall-plates, and rest in niches 
 in the rock. Another plan is to insert bearers at regular intervals 
 say every 30 feet under the end-pieces. The bearers are generally 
 of oak, and in a shaft of medium size pieces 12 inches by 12 
 inches are taken, and cut four or five feet longer than the end- 
 pieces. They therefore project 2 to 2 feet 6 inches at each end 
 into solid ground, and decidedly add to the security of the timber 
 lining. 
 
 The sides of the shaft are further prevented from falling in by 
 planks which rest against the wall-plates and the end-pieces. 
 During the process of sinking, the last frames are kept in position 
 by strong iron clamps, and when a length of 10 or 12 feet has been 
 completed, planks (lashings or listings) are nailed on inside, stretch- 
 ing over several frames and so binding them all together. 
 
 This lining of a shaft may be regarded as a very long box, 
 with strengthening ribs at short intervals. As shafts are 
 frequently used for the several purposes of pumping, hoisting, and 
 affording means of ingress and egress by ladders, it becomes 
 necessary to divide them into compartments. Pieces of timber 
 parallel to the end-pieces (bunions or dividings) are fixed across 
 the shaft, and serve to stay the wall-plates, to hold the guides or 
 
233 
 
 ORE AND STONE-MINING. 
 
 conductors, to support planks (casing boards), which are nailed to 
 them so as to form a continuous partition or brattice, and to 
 assist in carrying the ladder platforms. 
 
 The magnificent timbering of some of the shafts on the 
 Comstock lode is described by Mr. James D. Hague* as follows : 
 
 " The timbering consists of framed sets or^cribs of square 
 timber, placed horizontally 4 feet apart, and sejM-ated by uprights 
 or posts introduced between them. Gross-timbers for the par- 
 titions between the compartments form a part of every set. The 
 whole is covered on the outside by a lagging of 3 -inch plank 
 placed vertically." 
 
 Figs. 257, 258, and 259, copied from Mr. Hague's plates, illustrate 
 this method of timbering. Fig. 257 is a plan of the shaft. " S S 
 
 FIG. 257. 
 
 - --- h/^i ~~ 
 
 are the longitudinal or sill-timbers; T T, the transverse end 
 timbers ; r, guide-rods between which the cage moves ; g, gains 
 cut in the sill-timbers to receive the ends of the posts. The 
 sheathing or lagging is seen enclosing the whole frame." 
 
 Fio-. 258 is a transverse section through the partition-timber 
 (dividing) P, of Fig. 257, " between the pumping compartment 
 
 FIG. 258. 
 
 and the adjoining hoisting compartment, looking towards the 
 latter. In this figure, G G are the posts; S, the sill-timbers; 
 P, the partition-timbers, the ends of which are framed with short 
 
 * " Mining Industry," Un ted States Geological Exploration of the Fortieth 
 I'arallel, vol. iii. p. 103. 
 
 
SUPPORTING EXCAVATIONS. 
 
 239 
 
 tenons that are received in gains cut in the sill-timbers and the 
 ends of the posts ; r, guide rod ; I, lagging or sheathing.'' 
 Fig. 259 is an end view of the frame shown in Fig. 257. 
 
 " The single piece T forms the end, while the double pieces P, 
 forming the partitions, are seen beyond. The outer timbers of 
 each set that is, Uie two sides and ends of the main frame are 
 14 inches square jf^he posts, ten in number, four at the corners 
 and two at each end of the partitions, are of the same size. The 
 dividing-timbers forming the partitions are 1 2 inches square." 
 
 The pigsty system of supporting ground has been applied to 
 an inclined shaft at Day Dawn* Mine in Queensland, in which 
 the ordinary system of frames was proving inadequate. In this 
 case the shaft had been sunk on the inclined lode ; the ore had 
 been removed on each side and replaced by " deads," and the 
 sides and roof were supported by ordinary frames and laths. The 
 manager took out a strip of deads on each side of the shaft, and 
 as soon as sufficient room had been made, he built up a couple of 
 pigsties, and then another two, and so on. The space between 
 them served as a passage (winze) for winding-up the deads as the 
 work progressed downwards. The ends of the long horizontal 
 balks of iron-bark timber (caps) stretching across the shaft were 
 made to rest upon the pigsties, and upon them were placed poles 
 which supported the roof (hanging-ivall). Since this method has 
 been adopted there has been no trouble with the shaft. The 
 subsidence of the hanging- wall has been going on, but the pigsties 
 
 yield to the movement without becoming crippled or useless. 
 Occasionally a cap piece breaks in the middle, in spite of its great 
 size, but it can easily be renewed. 
 
 As an example of another large shaft may be mentioned the new 
 
 * MS. information kindly supplied by Mr. Joseph Shakespear, Govern- 
 ment Inspector of Mines, Queensland. 
 
240 
 
 ORE AND STONE-MINING. 
 
 sinking at the Calumet and Hecla mines* (Fig. 260), which is ex- 
 pected to strike the copper bed at a depth of 3325 feet from, the 
 surface. The shaft is rectangular, 23 feet by 13 feet 6 inches 
 within the timber, and divided into bix equal compartments, 7 feet 
 by 6 feet 3 inches within the timber. A and B (Fig. 260) are for 
 receptacles for winding rock, C and D for cages for raising and 
 lowering men, timber, &c. ; E forms the upcast air-way, and F is 
 for air-pipes, &c. The frames and the dividing- pieces are made 
 of southern pine, 1 2 inches by 1 2 inches, and the whole is sur- 
 rounded by a close lagging of 3-inch plank. 
 
 At Clausthal in the Hartz, round timber is generally used, and 
 special means are adopted for resisting the heavy pressure of the 
 ground upon the wall-plates. 
 
 In Fig. 261 a a are the wall-plates, made of timber i foot in 
 
 FIG. 261. 
 
 
 *$ 
 
 a 
 
 o 
 
 
 (*)- 
 
 i5L 
 
 
 y ^ 
 
 c //'<?: ____> 
 
 3 
 
 i t /*? '#-" , 
 
 'J 
 
 
 4 
 
 d 
 
 
 d 
 
 o> 
 
 eg 
 
 6 
 
 
 
 
 
 Id 
 
 
 
 
 ^J 
 
 
 w 
 
 [ 
 
 ( 1 
 
 \ / 
 
 jj 
 
 3 
 
 diameter; & 6, the end-pieces; e e, the studdles, which are 18 
 inches long. 
 
 The end-pieces are not halved as in Fig. 255, but are slightly 
 wedge-shaped, so as to preserve their whole strength for prevent- 
 ing the wall-plates from being squeezed together. However, reli- 
 ance is mainly placed upon frameworks of round timber, 15 inches 
 in diameter, placed at the ends and near the middle of the shaft, 
 and shown in elevation in Fig. 262. Each framework consists of 
 two pieces, 1 8 to 20 feet long (wall-posts, c c), kept apart by dia- 
 gonal struts (stempels or spur-timbers, d, d', d"). The foot of the 
 lowest stempel fits into a hitch cut in the long wall -post, whilst the 
 head is merely hollowed out to suit the curvature of the opposite 
 wall-post. All the other stempels are cut out in this way at both 
 ends, and when the bottom stempel has been put in, the others 
 are very speedily fixed one above the other. If necessary, a strong 
 bearer, h, is put in from time to time under the wall-posts, and 
 projects a foot or 18 inches into the ground on each side of the 
 shaft ; thin poles placed vertically and horizontally,/ and g, pre- 
 vent loose stones from falling in. 
 
 * Engineering, vol. 1., 1890, p. 553. 
 
SUPPORTING EXCAVATIONS. 
 
 241 
 
 Special excavations have to be timbered according to circum- 
 stances; thus a chamber for a water-wheel at Clausthal in the 
 
 FIG. 262. 
 
 FIG. 263. 
 
 Hartz was made decagonal (Fig. 263). The main horizontal pieces 
 at the side were of lo-inch round timber cut at the ends to the 
 
242 
 
 ORE AND STONE-MINING. 
 
 proper angle; behind them came half-round timber, trees 12 or 
 14 inches in diameter sawn in half, arranged vertically, and 
 finally a backing of common planks ; the successive horizontal 
 frames were kept apart by studdles, one at each end of each side 
 of the polygon. 
 
 Spilling. When ground is loose, recourse is had to a spilling 
 process like that described for levels. Strong balks of timber are 
 
 FIG. 264. 
 
 A 
 
 
 
 & I ^ 
 
 
 
 
 
 
 
 
 
 c 
 
 PLAN 
 
 C 
 
 
 
 
 & b * 
 
 
 
 7 
 
 
 1 
 
 SCALE 
 
 1234 
 
 5 
 
 'LET- 
 
 
 
 
 
 I 
 
 MET 
 
 fixed at the surface or in solid ground in the shaft, and the first 
 frame is supported upon these bearers ; the next frame is hung 
 from the first, the third from the second, and so on until the loose 
 ground is passed. 
 
 In Fig. 265 a a are the " bearers," which are made to project a 
 couple of feet into solid ground ; upon them rest the end-pieces 
 b b (Figs. 264 and 265), halved at the ends so as to support the 
 two wall-plates c c ; e e are two rods of 2-inch round iron, which 
 hold up the end-piece d of the second frame or " set of timber." 
 They are fixed tightly by means of cotters. The wall-plates ff of 
 the second frame rest upon the end-pieces in the usual way, and 
 when it becomes necessary to put in a third set or frame, the end- 
 pieces g are hung by cottered bolts from the frame above, d h h 
 are the wall-plates. The fourth frame with its end- piece i and 
 wall-plates j follows in the same manner ; therefore, until the 
 pressure of the ground comes into play, the bearers a a are carry- 
 ing the whole weight of the timber. The pieces k k, known as 
 
SUPPORTING EXCAVATIONS. 
 
 243 
 
 "laths," are made of 2 -inch plank, 9 or 10 inches wide, sharpened 
 at the ends ; they serve to keep the loose ground from falling 
 into the shaft; II are the so-called " tailings " which keep the 
 laths in position. The lath k' is one which is being put in ; it 
 has to be struck with a heavy sledge until it makes its way into 
 
 FJG. 265. Sectional elevation along line A A of Fig. 264. 
 
 the loose ground. If very heavy blows are required, the head of 
 the lath is protected by an iron shoe. 
 
 The piece m is a stay put in for the purpose of keeping the set 
 or frame in its place until the laths have been driven. The 
 frames are kept at the proper distance apart, and the timber 
 structure is stiffened by the usual corner posts n n (studdles). 
 
244 
 
 ORE AND STONE-MINING. 
 
 The loose ground is exc avate J. gradually, while each protecting 
 sheath of planks is in piocess of being driven down, and in due 
 
 course another frame is 
 hung on, and the opera- 
 tions of driving laths and 
 excavating are repeated. 
 
 At mines on the Corn- 
 stock lode, the bolts for 
 keeping the frames to- 
 gether are made in two 
 parts, with a tightening 
 screw in the middle ; great 
 firmness is secured in this 
 manner. 
 
 Working Places. 
 The timbering of working 
 places varies very greatly. 
 The simplest case is that 
 of a horizontal bed. Here, 
 props put in vertically of ten 
 
 suffice to support the weight of the roof. The addition of a lid, a 
 flat or slightly wedge-shaped piece of board at the top, extends the 
 bearing surface, and, by presenting a smooth face to the top of the 
 prop, enables this to be forced in more firmly into position than ifc 
 could be against a rough roof. It also yields a little to the pres- 
 sure of the roof, and lengthens the life of the prop in this way. 
 
 When the bed is inclined, the props are not set quite at right 
 angles to the plane of bedding ; one reason for this is that if so 
 set they might be easily knocked out by an accidental blow from a 
 falling stone. 
 
 Mr. Sawyer* has made out a table showing the deviation from 
 the normal which should be given : 
 
 
 Set or Underset of Po&ts. 
 
 Dip ol Scam. 
 
 
 
 Minimum. 
 
 Maximum. 
 
 6 
 
 o 
 
 1 
 
 12 
 
 
 
 2 
 
 18 
 
 1 
 
 3 
 
 24 
 
 1 
 
 4 
 
 3 
 
 2 
 
 5 
 
 36 
 
 2 
 
 6 
 
 42 
 
 2 
 
 7 
 
 48 
 
 3 
 
 8 
 
 54 
 
 3 
 
 9 
 
 and upwards 
 
 
 
 __^ I __ 
 
 Accidents in Mines from Falls .f Hoof and /Sides, London, 1886, p. 50. 
 
SUPPORTING EXCAVATIONS. 
 
 245 
 
 Fig. 266, copied by permission from Mr. Sawyer, is an instance 
 of a prop and lid f jr working in a bed of clay ironstone. 
 
 Logs laid two by two crosswise (chocks or cribs], the pigsties 
 of the Australian miner, form efficient supports. Fig. 267 repre- 
 sents the manner of using them in abed of potter's clay; Fig. 268, 
 
 FIG. 268. 
 
 FIG. 267. 
 
 20 /> 
 
 one of the huge structures which may be seen in the Wieliczka 
 salt mines ; and lastly, Fig. 269,* the method adopted at Day Dawn 
 
 113. 269. 
 
 gold mine, Queensland, in the case of a vein. The pigsties for 
 supporting the hanging wall are built up at intervals in the work- 
 
 * Kindly furnished by Mr. Joseph Shakespear, Government Inspector of 
 Mines, Queensland. 
 
246 
 
 OBE AND STONE-MINING. 
 
 ing places (slopes), and then filled up with rubbish (deads, mullock). 
 The pigsties on the foot -wall serve to keep up a portion of the vein 
 until it is time to break it down. Square timber is used for 
 chocks as well as round. * 
 
 According to Heathcote, the " square set " system of timbering, 
 so largely used in the TJnited States, is not an invention of 
 American origin, as is usually supposed. It appears to have been 
 
 FIG. 270. 
 
 FIG. 271. 
 
 known in Australia as lono ago as 1854. The manner in which 
 it is employed in Nevada for working away the soft " bonanzas," 
 or ore-bodies of the great Comstock lode (Figs. 270, 271, and 272) 
 is well described by Hague.f It consists in framing timbers 
 together in rectangular sets, each pet being composed of a square 
 
 base placed horizontally, formed 
 
 Fio. 272. O f f our timbers, sills, and cross- 
 
 pieces, 4 to 6 feet long, framed 
 together, surmounted by four 
 posts 6 to 7 feet high, at each 
 corner, and capped by a frame- 
 work similar to that of the base. 
 These cap-pieces, forming the top 
 of any set, are at the same time 
 the sills, or base, of the next 
 
 set above, the posts, as the sets rise one above the other in the 
 stope, being generally placed in position directly over those 
 below. 
 
 " The timbers are usually of 1 2-inch stuff, square hewn or 
 sawn." Each post has a tenon 9 inches long at the upper end, 
 and a tenon of 2 inches at the other end, which fit into mortices 
 in the cap and sill respectively ; and " the sills and caps have 
 short tenons on each end, and shoulders cut to receive the ends 
 of the post and the horizontal cross-pieces." The walls of the 
 excavation are sustained by a lagging of 3-inch or 4-inch plank. 
 
 * Discussion upon Messrs. Jamieson and Howell's paper, " Mining and 
 Ore -treatment at Broken Hill, N.S.W." JUin. Proc. Inst. C.JS.,vol. cxiv., 
 Session 1892-93. Part IV, 
 
 t Op. cit., p. 112. 
 
SUPPORTING EXCAVATIONS. 247 
 
 The whole width of the ore-body is stoped away at once, and its place 
 supplied by timbering, and finally the vacant space is filled with 
 waste rock derived from dead work in the mine or from special 
 excavations underground quarries in fact in barren ground. 
 The stoping is carried on overhand, starting from an intermediate 
 shaft or winze, and Fig. 272 will explain how the different frames 
 are built up one above the other. 
 
 In the Eureka district, Nevada,* the system employed for 
 securing the chambers left by the excavations of the ore-bodies is 
 
 FIG. 
 
 by similar square sets, but the mode of joining the pieces of 
 timber presents some peculiarities. 
 
 Fig. 273 is a general view of a square set employed at the 
 Richmond mine, which explains the manner in which the 
 tenons and shoulders are cut. This complicated method of 
 framing is admitted to be expensive, but its adherents claim that 
 it possesses great strength. At Eureka mine the joint is simpler. 
 The Eureka timbering is designed for resisting pressure in all 
 directions, the Richmond method for offering the greatest resist- 
 ance in the direction of the caps, the ties being placed parallel 
 to the walls. 
 
 * Curtis, " Silver-lead Deposits of Eureka, Nevada," Hon. U.S. Geol. 
 Survey, vol. vii. p. I 4. Washington. 1884. 
 
248 
 
 ORE AND STONE-MINING. 
 
 The dimensions of the pieces between the shoulders are : posts 
 6 feet, caps 5 feet, ties 4 feet, and the timber employed is pine 
 
 FIG. 274. 
 
 SCALE OF METRES 
 
 from the Sierra Nevada, hewn into balks 12 by 12, 10 by 12, or 
 10 by 10 inches. 
 
SUPPORTING EXCAVATIONS. 
 
 249 
 
 Square sets are likewise adopted at the Broken Hill mines* 
 where a wide and soft lode has to be stoped away (Figs. 274 and 
 275), and they are being tried in Hodbarrow mine in Cumberland. 
 The joint used at Broken Hill t is represented in plan by Fig. 2 7 6, in 
 which A A are the caps, B B the struts, and C the tenon 4 inches 
 
 FIG. 277. 
 
 ITU fl Q 
 
 square on the end of the upright post or leg. Fig. 277 explains 
 the manner of packing the hanging wall with timber, so that the 
 load may be distributed evenly upon the supporting framework. 
 It also shows how a weak spot 
 at A is further secured by 
 horizontal stays. 
 
 When additional strength is 
 required, a lining A (Fig. 278), 
 or an angle-stay, B, is put in ; 
 and should these precautions 
 appear insufficient to prevent 
 a movement of the ground, the 
 framework may be reinforced 
 in various ways, as illustrated 
 by C, D, E and F (Fig. 278) ; 
 F is a solid ro-inch wall of 
 
 timber. 
 
 MASONRY. Masonry has long been used for supporting 
 the roof and sides of mining excavations. The materials necessary 
 are stone, ordinary bricks or slag-bricks, and they may be built 
 
 * Victoria, Annual Report of the Secretary of Mines for the Year i8Sg t 
 p. 36. 
 
 t lleathcote, op. cit. 
 
2 5 
 
 ORE AND STONE-MINING. 
 
 up alone (dry walling), or with the aid of mortar or hydraulic 
 cement. Concrete, a mixture of hydraulic cement and small 
 
 FIG. 279. 
 
 stones, is occasionally employed, and probably could be more so 
 with advantage. 
 
 Once more I will take the three cases of a level, a shaft, and a 
 working place. 
 
 Levels. In levels dry walling and timber are sometimes 
 
 FIG. 280. 
 
 combined. Thus, after the excavation of a wide lode, the 
 rubbish is piled up on the sides, walls are built up of the large 
 
SUPPORTING EXCAVATIONS. 251 
 
 stones, and caps of timber are laid across, which support the 
 " deads " when the higher portions of the lode are taken away. 
 
 Fig. 279 represents a level in an iron mine in the Forest of Dean, 
 where sandstone is available. The pieces are hewn and trimmed 
 roughly, and a semi-circular arch is made to rest upon walls at 
 each side. 
 
 Fig. 280 is a level in one of the mines at Clausthal in the Hartz ; 
 the sides are constructed of slag-bricks, and at the bottom of the 
 tunnel there is a channel, made of concrete, for carrying water and 
 preventing its percolation into lower workings, which would other- 
 wise necessitate unprofitable pumping. 
 
 If both sides (walls) of a vein (Fig. 281) are firm, an arch affords 
 ample protection when the ore has been removed, and provides a 
 resting place for the rubbish (deads, attle Corn.) 
 
 A vein is very often a fault, and soft beds may be found 
 
 FIG. 281. 
 
 FIG. 282. 
 
 opposite a hard wall of solid rock. In this case the arch is made 
 to reach from the roof to the floor (Fig. 282). 
 
 One of the main crosscuts at Mansfeld* was lined with concrete 
 for a length of 1000 m. (| mile) ; 12 metres (40 feet) a day were 
 put in, and for this purpose 50 metres (164 feet) of centering 
 were required. The laths were covered with thin sheet-iron, so 
 as to prevent the concrete from sticking. The concrete was made 
 of Portland cement, broken stone, and gravel, in the proportion of 
 i to 7, viz., i part of cement, 2 J- of broken stone, and 4^ of gravel. 
 Up to a height of 16 inches (40 cm.) from the ground, the layer of 
 concrete was made thick enough to join on to the sides of the 
 level, in order to assure a firm foundation. Above that height it 
 was made only 6 inches thick, the sides of the level having been 
 previously built up with dry walling. 
 
 The centering could be removed at the end of three clays, but it 
 was usually kept in four or five. It was found that five men could 
 
 * Pamphlet describing the exhibits of the Mansfeld Company at the 
 Berlin Exhibition for the Prevention of Accidents, 1889, p. 20. 
 
2 5 2 
 
 ORE AND STONE MINING. 
 
 FIG. 283. 
 
 put in 6 m. (20 feet) of concrete lining in a shift of twelve hours. 
 The cost per running metre was 31 marks 70 pf. (i 8s. 4^. per 
 yard). 
 
 Shafts. Like levels, shafts are lined with masonry, brick- 
 work, or concrete, and these have the advantage of being far 
 more permanent than timber, and of requiring fewer repairs. 
 
 When due weight is given to the fact that the shafts are usually 
 the main thoroughfares of a mine, the necessity of having a lasting 
 lining becomes very evident. 
 
 This kind of shaft-lining is especially desirable in loose ground 
 near the surface, because if the working is discontinued tem- 
 porarily, the shaft still remains secure and available for use at any 
 future time ; whereas if timber is put in, it soon decays, the top of 
 the shaft collapses, and much expense is incurred in the process 
 of reopening it. 
 
 Another immense advantage of a shaft without timber is its 
 immunity from fire. 
 
 The section of walled shafts is generally circular, as affording 
 the best resistance to pressure. Elliptical walling is also met with, 
 and sometimes the two long sides are made 
 with a flat curve, and the two ends with a 
 curve of much shorter radius. The wall- 
 ing may be dry or with mortar, according 
 to circumstances. The masonry lining is 
 put in either in one length, or in successive 
 rings or sections in descending order, and 
 this is the usual plan. 
 
 The shaft is sunk to a certain depth 
 with a temporary lining of timber, and 
 when firm ground has been reached, a bed 
 is cut out on which is placed a crib or 
 curb, A B, Fig. 283,* consisting of seg- 
 ments of timber forming a ring. This 
 serves as a foundation for the brickwork, 
 which is built up to the surface ; the tem- 
 porary timbering is sometimes left in and 
 sometimes removed as the work progresses, 
 and any vacant space is filled up with earth 
 or concrete. Sinking is then resumed, and of a smaller diameter for 
 a certain distance, so as to leave a bracket or ledge to support the 
 curb. On arriving, after a certain depth of sinking, at another firm 
 bed, a second curb, D, is put in, and a second ring of brickwork 
 built up. When the intervening ledge of rock is reached, it is 
 carefully removed in small sections, and the brickwork brought 
 up to the first curb. This process is repeated until the shaft is 
 completed, or reaches rock in which no masonry is requisite. If, 
 
 * J. Gallon, Lectures on Mining, vol. i. atlas, plate xxviii. 
 
SUPPORTING EXCAVATIONS. 
 
 253 
 
 owing to the nature of the ground, it is impossible at first to find 
 firm seats for the curbs, it becomes necessary to hang them by iron 
 bolts from a strong bearing frame at the surface, or to support 
 them on iron bars fixed in the sides. 
 
 Fig. 284 shows a concrete lining put in at the top of the main 
 shaft at Foxdale mine, in the Isle of Man. The shaft is rect- 
 angular, 13 feet 6 inches by TO feet 6 inches. The concrete serves 
 not only to support the sides in the loose, weak ground near the 
 
 FIG. 284. 
 
 C--4.'- -> 
 
 -JO' .6' 
 
 top, but also to keep out much of the surface water. The concrete 
 was made of 4 parts by volume of stones 2^ inches to 3 inches 
 across, 2 parts of sharp sand and i of Portland cement, and the 
 total cost for materials and labour was 135. 6d. per cubic yard. 
 
 Some shafts in Germany have lately been lined with concrete 
 blocks shaped so as to fit the curvature of the sides,* Each block 
 is fluted at the top and at the ends, whilst the bottom has a bead- 
 ing, which lies in the channel of the block below it. As the 
 blocks may weigh as much as one-third of a ton each, it is con- 
 venient to have some easy means of handling them. A vertical 
 hole is therefore left in each block which receives a ring bolt, 
 fixed by a cotter inserted through a horizontal hole. The block 
 can then be easily slung to a rope and lowered into position, and 
 on knocking out the cotter the bolt can be withdrawn. The 
 spaces between the blocks, and also the bolt-holes, are filled with 
 cement ; the shaft thus receives what is practically a solid lining 
 of concrete, which, besides supporting the ground, keeps back 
 water and acts the part of tubbing. As pointed out by Mr. 
 
 * Zeitschr.f. B.- II.- it. S.-Wesen, vol. xxxix. 1891, p. 98. 
 
254 
 
 OUE AND STONE-MINING. 
 
 Brough,* a lining of this kind has the advantage over cast-iron 
 and timber of not corroding or decaying, besides which its strength 
 increases with age, and any expansion or contraction from changes 
 of temperature are inappreciable. Finally, it is far cheaper than 
 a lining of brickwork or iron. 
 
 The Monier system consists in strengthening the concrete by a 
 coarse net-work or skeleton of iron wire embedded in it. Re- 
 inforced in this way, the fabric has greater tensile strength. 
 
 Working Places. In temporary excavations, like working 
 places, rough pillars, built up of lumps of waste stone or of the 
 
 FIG. 285. 
 
 useful mineral itself, will take the place of timber in supporting 
 the roof, or may be used as an adjunct to it, as is the case in 
 Fig. 285, borrowed from Mr. Sawyer. f 
 
 The timber at the top serves to make the pressure come 
 gradually upon the stone. The post is eventually drawn out and 
 the stone recovered. 
 
 Walls are also built up with waste stone enclosing spaces which 
 are filled up with any available rubbish ; and in some instances 
 excavations are entirely packed with rubbish after the removal of 
 the useful mineral. 
 
 It is only in exceptional cases that it is possible to incur the 
 expense of building pillars with cement or mortar to support 
 the roof and sides of working places ; but masonry or concrete 
 
 * Notes on the Use of Cement in Shaft-Sinking,' 
 If. E., 1893. 
 t Op. cit., Fig. 4. 
 
 Proc. N. E. Inst. 
 
SUPPORTING EXCAVATIONS. 
 
 2 S5 
 
 arches may be constructed for carrying the rubbish used for filling 
 the vacant places left by workings upon mineral veins. 
 
 METALLIC SUPPORTS. There are various ways of using 
 iron and steel as supports for levels, shafts and working places, 
 
 Levels. In one part of the Halkyn Drainage tunnel, Flint- 
 shire, a combination of cast-iron and wrought-iron has been em- 
 ployed. Much of the level is in hard, solid limestone, and requires 
 no lining of any kind ; but where small beds of shale were inter- 
 mixed with the harder rock, timber supports were put in. As the 
 timber originally used was showing signs of decay, it was decided 
 in 1887 to replace it by a more lasting material iron. 
 
 The nature of the Halkyn supports will be easily understood 
 by Fig. 286. There are two vertical props ov legs, which are hollow 
 cylinders of cast-iron, 6 feet 6 inches long, 5 inches in diameter 
 
 FIG. 285. 
 
 FIG. 287. 
 
 -5 ins-- 
 <4 lns> 
 
 <- 9 ins 
 
 externally, and 4 inches internally, with a flange 8 inches in 
 diameter at the top, and 9 inches in diameter at the bottom. 
 
 A chair, shown in section by Fig. 287, drops into the top of the 
 iron column, and receives a reversed iron rail, 7 feet long, weigh- 
 ing 117 lb. (50 Ib. to the yard), the precise shape of which is 
 shown on a larger scale by Fig. 288. The iron frames are placed 
 about 3 feet apart, planks or rails are laid from one to the other, 
 and the space between them and the roof tightly packed with 
 stones. A dry stone wall is built up on each side, with an occa- 
 sional plank or rail to make it firmer. Fig. 286 also shows a timber 
 
2 5 6 
 
 ORE AND STONE MINING. 
 
 " spreader " above the water level, carrying longitudinal sleepers 
 with bridge rails forming a waggon-way with a 26-inch gauge. 
 
 This method of support is designed for a case where the roof is 
 weak, and where no great pressure is expected from the sides. Ib 
 
 FIG. 288. 
 
 FIG. 289. 
 
 would evidently be unsuitable for the Cornish County adit in 
 Gwennap, because the water would speedily eat away the iron. 
 In the Halkyn adit, however, no corrosion need be feared ; for 
 iron rails which were laid near the mouth of the tunnel very many 
 years ago have not been injured by the water. Its cheapness, as 
 compared with the cost of the walling, was the reason why iron 
 was adopted in Flintshire. It was estimated that to secure this 
 part of the adit with the best Buckley brick and hydraulic lime, 
 would cost over ^4 per yard, whereas the present method has cost 
 only 2 45. per lineal yard of tunnel. It cannot be denied that 
 a brick lining would be more permanent, as the planks in the roof 
 of the level will have to be replaced from time to time ; but the 
 cost of repairs is likely to be slight. In more recent work iron 
 rails and old fire-bars are used instead of wooden lagging. 
 
 Steel beams have been used with success for some years at the 
 Nunnery Colliery, Sheffield, in the place of timber. They are of 
 I-section, 4 inches wide, 5 inches deep, with the web f inch thick 
 (Fig. 289), and they are considered by Mr. Bainbridge, the manag- 
 ing director of the colliery, to be of the same strength as 1 2-inch 
 Norway balk. The beams are supplied in lengths of 6, 7, 8, 9, 
 and 10 feet, so as to suit drivages of various widths. There are 
 two ways of using them (i) as " bars," or caps, resting upon the 
 timber legs; (2) as legs and caps. 
 
 Fig. 290 shows the former method a, horizontal cap, 10 feet 
 long, rests upon two legs of round Norway timber, 8 to 10 inches in 
 diameter, and a lug or band of wrought iron, if inch by J inch, 
 shrunk on, prevents the leg from coming in sideways. The 
 frames or sets are generally placed 3 feet apart, and old timber 
 laid across from cap to cap forms the so-called lofting supporting 
 the roof. 
 
 The steel beams are tarred over with unboiled gas tar, and 
 some have been in use several years without showing any signs of 
 deterioration, whereas the average life of English larch or Norway 
 timber, at this colliery, is only two years. 
 
SUPPORTING EXCAVATIONS. 
 
 257 
 
 The beams cost about $ los. per ton, delivered at the colliery ; 
 in other words, a i o-f oot beam costs 85. A beam of Norway timber 
 10 feet by 12 inches by 12 inches would contain 10 cubic feet, 
 and at 8%d. per cubic foot, would cost >js. id. The difference in 
 original cost is therefore not very great. 
 
 FIG. 290, 
 
 Scale 
 Incties 12 6 / 2 3 4 S 6 7 8 9 
 
 The advantages of the steel over timber beams are numerous : 
 
 1. Greater durability, which means a great reduction in the 
 cost of repairs. 
 
 2. Possibility of using the beams elsewhere when taken out. 
 If bent slightly, they can be reversed ; if badly knocked about, 
 they can be sent to the steel works and worked up again. In any 
 case, they are of some value. 
 
 3. Lightness and handiness. A 10 -feet steel beam weighs 166 
 Ibs. ; a lo-feet beam, 12 inches square, of Norway timber, weighs 
 3 cwt. The steel beams are not only lighter, but also less bulky, 
 and consequently more easily handled. Therefore men can do 
 more work in a given time. 
 
 4. Increased space for ventilation. The free space in a level 
 will be from 5 to 7 inches higher with steel than with timber in 
 lining an excavation of a given size. Six inches added to a height 
 of 6 feet means an increase of i-i2th, or 8| per cent., in the area 
 of the airway. 
 
 5. Less deterioration of the air of the mine by decaying timber. 
 
 6. No danger from fire. 
 
 When girders are used as legs as well as caps (Fig. 291), a plate 
 
258 
 
 ORE AND STONE-MINING. 
 
 of rolled steel, of the shape shown in Figs. 292 and 293, is placed 
 at each extremity of the leg. The plate is J inch thick, 6| inches 
 
 FIG. 291. 
 
 FIG. 292. 
 ^ ^ *r 
 
 FIG. 293. 
 
 long, by 6 inches wide, with a slot J inch wide and 2^ inches long. 
 The web of the leg passes into this slot and is thus prevented from 
 slipping sideways, while the turned-up rim prevents slipping out- 
 wards or inwards. 
 
 Lugs of wrought iron arc shrunk on to the cap as in the 
 previous case. 
 
 In making the comparison of cost, it is necessary to recollect 
 that I have chosen a case extremely favourable to steel, because 
 the beams are made at Sheffield, and any waste material can be 
 
 worked up again on the spot with- 
 out having to pay a heavy cost of 
 carriage back to the steelworks. 
 
 One kind of joint used in Bel- 
 gium* for I-iron is a flanged 
 bonnet of cast-iron, which receives 
 the top of the leg and one end of 
 the cap. A wooden wedge is placed 
 in the bonnet under the cap, so as 
 to give a certain amount of elas- 
 ticity to the frame. 
 
 In doing work with a new ma- 
 terial, a servile imitation of the old 
 forms is often remarked. The fact 
 of timber being most readily obtainable in straight pieces naturally 
 led to the adoption of rectangular, trapezoidal or polygonal forms 
 for supporting linings ; but there is no necessity with iron or steel 
 for copying the shapes which are most suitable with wood. This 
 \\as recognised by the Germans in the early days of iron supports. 
 A method in use in the Hartz in 1872 consisted in bending an iron 
 
 : * Habets, "Le materiel et les precedes de 1'Exploitation des Mines," 
 Extraits des Rapports du Jury International des Recompenses de T Exposition 
 Universelle d'Anvers, 1885. Paris and Liege, 1887, p. 61. 
 
SUPPORTING EXCAVATIONS. 
 
 259 
 
 rail as shown by Fig. 294, and making it support other rails laid 
 longitudinally, against which flattish stones were placed ; the 
 vacant place between these and the rock was filled with rubbish. 
 The ends of the rails were footed in holes cut in large stones. 
 
 FIG. 295. 
 
 Some neat and effective forms of steel supports are made in 
 France, where more attention has been paid to the subject than 
 in this country. 
 
 Three kinds made of I-steel by the " Societe anonyme des 
 
 FIG. 296. 
 
 Hauts-Fourneaux, Forges et Acieries de Denain et d'Anzin," will 
 serve as good examples of steel supports for levels. 
 
 Fig. 295 is a slightly bent bar, the ends of which are made to 
 
260 
 
 ORE AND STONE-MINING. 
 
 FIG. 297. 
 
 rest upon dry walls at the sides of a level. It, therefore, takes 
 the place of an arch. Fig. 296 represents a favourite form of 
 lining for levels ; it is composed of two 
 side-pieces suitably bent at the top, and 
 united by a couple of fish-plates (Fig. 
 297) and four bolts; in some cases a 
 cast-iron sleeve is used instead of the 
 fish-plates. When the floor is soft and 
 
 5 hvrYr^Yjrwj liable to " creep," the frame may be 
 
 | t made of three pieces (Fig. 298). 
 
 Some mines utilise old rails, weigh- 
 ing 36 to 40 Ibs. per yard (18 to 20 kil. 
 per metre) for frames. The rails are 
 bent into semicircles, and two of these 
 are united by sleeves of riveted sheet- 
 iron, in which they are kept tight by 
 wooden wedges. Elliptical frames are 
 used in the Freiberg district, made of 
 two pieces of rail held together by a 
 
 couple of fish-plates at the top and bottom. 
 
 FIG. 298 
 
 SCALE OF FEET 
 
 123' 
 SCALE. OF METRES 
 
 o-s 
 
SUPPORTING EXCAVATIONS. 
 
 261 
 
 The frames made by the " Compagnie des Fonderies et Forges 
 de 1'Horme " (Loire) are almost invariably composed of two semi- 
 circles of mild steel. Two kinds of sections are employed 
 
 FIG. 299. 
 
 3. 
 
 namely, channel steel and bulb tee steel. Bars of channel steel, 70 
 
 mm. x 40 mm., weighing 16 Ibs. to the yard, are sawn into proper 
 
 lengths on leaving the rolls, and while still 
 
 hot are bent into semicircles. The ends 
 
 are carefully planed square, so that the top 
 
 semicircle may rest accurately upon the 
 
 lower one (Fig. 299). They are joined by 
 
 sleeves made of sheet-steel, fixed by a couple 
 
 of small iron wedges (Fig. 300). It is 
 
 claimed by the Horme Company that these 
 
 frames never give at the joint. 
 
 Steel of bulb tee section, weighing 26 Ibs. per yard, is employed 
 for heavier ground (Fig. 301). The sleeves are made of riveted 
 sheet-steel, and are fixed by two wooden wedges, one on each side 
 of the web (Fig. 302). Bars of U -steel of a hollow semicircular 
 section are used as the lagging ; the steel is | inch thick and about 
 i J inch in diameter, weighing scarcely 2 Ibs. per yard (i kilo, per 
 metre), and it is usually cut in lengths just sufficient to go from 
 one frame to the next. Small bars of steel of square section 
 are employed for the same purpose. 
 
262 
 
 ORE AND STONE-MINING. 
 
 Iron and steel may be used with advantage instead of timber 
 for the construction of supporting platforms (stulls) in vein- 
 mining. At Freiberg* full-sized rails are employed as cross- 
 beams (stull-pieces) ; they are covered with small mine rails, 
 
 FIG. 301. 
 
 FIG. 302. 
 
 and these with flat stones. Where the pressure is not very 
 great, wire rope is used for the covering. The rope is cut into 
 pieces about 2 metres long, and the ends are 
 welded up and bent into hooks. These pieces 
 are laid across the iron stull-pieces and 
 covered with stones and rubbish. 
 
 In places where the two walls of a lode are 
 likely to come together a little after a time, the 
 stull-pieces are cut about i or i inch shorter 
 than required, and a wooden wedge is put in at 
 each end. The pressure of the ground squeezes 
 up the wedges gradually, and finally the rock 
 comes against the iron. The rails used as stull- 
 pieces are often slightly arched so as better to 
 support the weight of the rubbish, and the flange of the rail is 
 placed underneath, as its long straight edge gives a better hold in 
 the rock than its head. The rails are not cut across at right angles 
 to their length, but are made somewhat longer above than below, 
 
 * Frciberys Bery- und HiUtenwescn, Freiberg i. S., 1893, P- J 7^ 
 
SUPPORTING EXCAVATIONS. 263 
 
 in order that they may not drop through if small pieces of rock 
 break off under them. In addition to all sorts of small rails, 
 old fire-bars and old boiler-plates are occasionally utilised for 
 " lagging." 
 
 A new departure in driving tunnels in soft ground is furnished 
 by the Greathead* shield, by the aid of which two long parallel 
 tunnels have been driven through clay and gravel, in London, 
 for passenger traffic by an electric railway. As cases may arise 
 in mines where- this method would be available, it is desirable to 
 explain briefly the mode of working adopted, and to indicate the 
 sources where full details will be found. The tunnels of the City 
 and South London Railway may most easily be described as long 
 tubes of cast iron, built up ring after ring as the excavation pro- 
 gressed. The rings are i foot 7 inches long, made in seven seg- 
 ments bolted together by f-inch bolts passing through the internal 
 flanges. They therefore closely resemble the watertight lining of 
 shafts known as " tubbing," to which reference will be made later. 
 
 The ground in the centre part of the end of the tunnel was dug 
 out, and a cylindrical shield was forced forward by hydraulic 
 jacks. The shield had a cutting edge and penetrated into the 
 clay under the pressure. The clay was removed as the shield 
 went forward, and at last, when the advance amounted to 20 
 inches, a new ring was formed by bolting together the segments, 
 which then exactly fitted the inside of the shield. The progress 
 of the shield left an annular empty 
 space ij inches deep between the 
 last ring and the surrounding clay, 
 equal to the thickness of the shield. 
 This was filled by injecting Lias 
 lime grout through a hole in each 
 segment, and so encasing the tunnel 
 in concrete. The average progress 
 per day was 13 feet 6 inches. 
 
 When the tunnel came to water- 
 bearing gravel and sand, it was 
 necessary to have an air-lock and 
 keep the water back by compressed 
 air. In order to prevent the escape 
 of air into the porous gravel, the 
 face was cut away in sections, and as each portion was exposed, a 
 jet of grout was played upon it to close the interstices. 
 
 Shaft Linings of Iron. Fig. 303 shows a method of temporary 
 support for sinking little shafts 30 or 40 feet deep. Iron rings, 
 4 feet 6 inches to 8 feet in diameter are employed to keep lining 
 planks in position. The rings are made in two or three segments, 
 bolted together inside. The iron used is from ii to 2\ inches 
 wide by \ inch thick. 
 
 * Engineering, vol. 1., 1890, p. 551. 
 
264 
 
 ORE AND STONE-MINING. 
 FIG. 304. 
 
 FIG. 305. 
 
SUPPORTING EXCAVATIONS. 
 
 265 
 
 FIG. 306. 
 
 The rings may be hung one from the other by iron hooks, and 
 channel iron may take the place of the flat iron in the circles 
 around the shaft. 
 
 Steel and iron rings are also used in the case of permanent 
 supports for shafts. The accompanying figure (304) shows the 
 lining of a shaft at Boryslaw, adopted by Herr Platz, the 
 director of the ozokerite mines be- 
 longing to the " Compagnie Com- 
 merciale Frangaise." The shaft 
 is kept open in very heavy ground 
 by rings of channel iron placed 
 
 1 metre apart from centre to cen- 
 tre. Each ring is made in two 
 halves and these are connected by 
 two special castings, with holes 
 for bolts ; they act the part of fish- 
 plates, two bolts being on one side 
 of the joint, and two on the other. 
 Around the rings come oak planks, 
 
 2 inches thick, and there are four 
 distance pieces (studdles or posts) 
 between every two rings. At 
 intervals of 2 or 3 metres, two 
 oak bearers are placed across the 
 shaft, which serve to take up the 
 weight of the rings if necessary, 
 though, as a rule, the pressure of 
 the ground holds the rings very 
 firmly. The bearers are also u 
 utilised for carrying the guides 
 or conductors for the cage. 
 
 Fig. 305 represents a ring simi- o ' i ' * ,o u ~ ' , a ao 
 lar to those used at Boryslaw, 
 
 made by the Witkowitz Ironworks for a shaft 8 feet 6 inches in 
 diameter, and Fig. 306 gives the details of the connecting piece 
 and bolts. 
 
 Working Places. We may start with simple cast-iron props 
 used instead of timber in places where they can be withdrawn. 
 They are rather heavy, but they will serve over and over again. 
 At some collieries a large number of these props, from 3 feet 
 6 inches to 5 feet 6 inches long, are employed, and they appear to 
 give satisfaction. Naturally they have to be made of the same 
 height as the particular seam which is worked, but any minor 
 irregularities in the roof are suited by the thickness of the lid, or 
 by making the lid of two pieces of board. They are set with the 
 small end downwards. Cast-iron props are not suited for resisting 
 cross pressures, and they are liable to break occasionally when 
 they happen to fall. 
 
 SCALE OF INCHES 
 
 SCALE OF MILLIMETRES 
 
266 
 
 ORE AND STONE-MINING. 
 
 How-ell's prop is a hollow lap-welded steel tube or pipe, 
 4 inches in diameter outside, with the ends expanded till they 
 are slightly conical, in order that the top may receive a 
 wooden plug which projects about f inch above the steel. These 
 props are used alone in working places, or in conjunction with 
 bars of I-steel, to support the roadways. The foot of the prop 
 in this case is set out about 6 inches in the bottom so as to pre- 
 vent it from coming in sideways. The object of the plug is to 
 obtain a certain amount of elasticity. 
 
 A third kind of prop is made of I-iron or steel, either cut off 
 square or with the web cut out for a few inches, and the two 
 flanges turned over so as to make ends with a larger bearing 
 
 FIG. 307. 
 
 FIG. 308. 
 
 surface (Fig. 307). The holes a a enable the props to be with- 
 drawn by a hook. 
 
 WATERTIGHT LINING-S FOR SHAFTS. We must 
 now turn to the spe3ial case of shafts which have to pass 
 through watery strata. Here it is often advisable to put in a 
 watertight lining, in order to prevent the inflow of water, and so 
 save the expense of pumping it out day after day, and year after 
 year. 
 
 The lining may be made of wood, brick, and hydraulic lime or 
 <sement, or, lastly, iron. 
 
 There are two kinds of wooden tubbing: (i) Plank tubbing, 
 whence this kind of lining originally received its name; and 
 (2) solid timber tubbing. Plank tubbing is made of boards from 
 2 to 3 inches thick, arranged vertically round the shaft and cut 
 with a bevel like the staves of a cylindrical barrel. The planks 
 are nailed on to rings of wood placed at suitable intervals. 
 
SUPPORTING EXCAVATIONS. 267 
 
 Solid wooden tubbing (Fig. 308) consists of carefully shaped 
 blocks of oak or elm, with thin sheets of deal placed between the 
 joints. The joints are wedged up as tightly as possible, and a 
 lining of this kind can be made so as to resist a very considerable 
 pressure of water, even 200 to 300 Ibs. per square inch.* 
 
 The method known as " coffering " consists in lining the shaft 
 with a wall made of brick and cement, or brick and hydraulic 
 lime, and backing this up with puddled clay. It is specially used 
 for keeping back the surface-water. 
 
 Full details concerning this method will be found in the paper t 
 quoted below, and my description may be very brief. In one 
 particular instance the shaft received first of all a temporary 
 lining of g-inch brickwork put in dry during the course of sinking, 
 the successive sections being held up by wooden cribs or curbs 
 that is to say, rings of oak placed 4 to 5 feet apart. Each ring 
 was hung from the one above it by vertical pieces of ij-inch plank 
 
 FIG. 309. 
 
 spiked on to both rings. When firm ground below the watery 
 strata had been reached, a level bed was cut for putting in the 
 wedging-crib a ring made of segments of cast-iron, either like 
 A or B in section (Fig. 309). By means of wedges driven in 
 behind, it was made perfectly tight and stanch. Three courses 
 of brickwork made with Roman cement were built up on the crib 
 and the wedges behind it ; they formed the foundation for the 
 "coffering " proper, which consisted of three rings of brickwork in 
 hydraulic mortar EE (Fig. 310), separated by the two rings of 
 hydraulic mortar F F, and the puddled clay D. B represents the 
 original lining of nine inches of dry brickwork put in against the 
 watery strata. As water running down the sides of the shaft 
 would render it impossible to carry out this kind of work satis- 
 factorily, means had to be adopted for getting rid of it. A 
 garland or circular launder was fixed around the shaft so as to 
 intercept it before it could interfere with the work of coffer- 
 ing, whilst water coming in behind the coffering was drawn off 
 during the progress of the work by placing a vertical launder 
 against the preliminary lining of bricks. This launder was pierced 
 with holes every three inches, and communicated at the bottom 
 
 * E. Bainbridge, " On the Kind-Chaudron System of Sinking Shafts 
 through Water-bearing Strata," Proc. Inst. C.E., vol. xxxiv., 1871-1872, 
 Plate 12. 
 
 t N. K. Griffith, ".On the Coffering of Shafts to keep back Water," 
 Trans. N. Eng. Inst. Min. Meek. Eng., vol. xxvi., 1876-77, p. 3. 
 
2 68 
 
 ORE AND STONE-MINING. 
 
 with a block of wood which had a 3-inch hole bored through it, 
 opening into the shaft just above the wedging-crib. As it became 
 
 FIG. 310. 
 
 Scale of Feel; 
 
 gradually buried by putting in the clay D, the holes were plugged 
 up, and finally the launder was filled with pieces of stone, and 
 cement was run in. 
 
 The walling was done with hydraulic mortar, made of one of blue 
 lias lime to two of sand, and the middle course was grouted in, 
 either with a similar mixture or with pure Roman cement. 
 
 The advantage of coffering over the ordinary metallic lining 
 known as tubbing is its cheapness. Mr. Griffith puts the cost of 
 coffering a shaft he sank at ;io 55. per yard, and he estimates 
 that a suitable cast-iron tubbing would have cost ^23 per yard. 
 The pit was 20 feet in diameter clear within the original lining of 
 dry bricks, and as the coffering was 2 feet thick, the final diameter 
 of the pit was reduced to 16 feet. 
 
 Where the ground is soft, a cast-iron lining may be made to 
 sink down by its own weight and by pressure applied to it. This 
 process was adopted at Restronguet Creek,* a branch of Falmouth 
 Harbour, in order to work a bed of stream-tin. The creek had 
 i o or 1 2 feet of water at high tide, and was nothing but a mud- 
 bank at low tide. A staging was constructed upon piles in the 
 creek, in order to have room for working, and a first cylinder, with 
 
 * Taylor, " Description of the Tin Stream Works in Restronguet Creek, 
 near Truro," Proc. lust. M.E., 1873, P- 1 SS- 
 
SUPPORTING EXCAVATIONS. 
 
 269 
 
 a cutting edge, was placed upon the mud, two more cylinders 
 were then bolted on, and their weight caused the whole to sink 
 down. The cylinders, made of cast-iron, were 6 feet high by 6 feet 
 in diameter and i| inch thick, and they were joined by internal 
 flanges faced in the lathe. Each ring weighed about 2 J tons, 
 and was lowered by a crane through an opening in the stage, 
 between guides in order to keep it vertical. When the first 
 three rings had ceased to sink, the mud inside was cleared out, 
 and further cylinders were added and forced down by pressure 
 from the chain of a crab-winch. Afterwards an ingenious method 
 of taking advantage of the rise and fall of the tide was resorted to. 
 A huge girder was laid across the top ring, and a barge laden 
 with stone was attached to each end. The fastening was made 
 complete at high water, and when the tide fell the full weight of 
 the barges came npon the girder, and so upon the shaft. The 
 cylinder was thus sunk to the full depth without difficulty. 
 During the sinking the core was always cleared out a little below 
 the bottom of the cylinder before the barges were attached, and, 
 if left for a day, the mud was found to swell up 3 or 4 feet into it. 
 A total weight of about 250 tons was required to sink the cylinder 
 
 *& 
 
 i%o 
 
 FIG. 311. 
 
 flf t Seotj, Q 
 
 as it neared the bed of tin ore. Altogether, thirteen of the 6 -feet 
 rings were sunk, making a total depth of 78 feet. 
 
 The ordinary method of tubbing is that in which the rings are 
 made up of segments, and as a rule the cylinder of cast-iron plates 
 is built up within some temporary lining ; this is carried down 
 until it reaches- some solid and impervious stratum below the 
 
270 
 
 ORE AND STONE-MINING. 
 
 water-bearing measures, fit to serve as a foundation. When such 
 a stratum has been found, the sinking is continued for a few feet, 
 and a bed is cut out very carefully, and trimmed perfectly even and 
 horizontal, so as to receive the first crib or curb similar to those 
 just described in the case of coffering. The curb is a hollow ring 
 of cast-iron made in segments about 4 feet long. Strips of deal 
 about J-inch thick are placed between every joint, and the seg- 
 ments are brought tightly together by wedging up the space be- 
 tween the outside of the curb and the rock. The joints are finally 
 rendered perfectly stanch by driving in wedges into the deal strips. 
 A second curb is laid upon the first, with intervening strips of deal, 
 and the wedging process repeated ; sometimes a third curb comes 
 upon the second. The top curb is the foundation for the tubbing 
 proper, which is built up segment after segment. The segments 
 are usually i to 3 feet high and 4 feet long (Fig. 311) ; their thick- 
 ness depends upon the pressure of water they have to withstand 
 and varies between ^ inch and 3 \ inches. They are smooth inside, 
 but are strengthened with flanges and ribs on the side turned 
 towards the ground. 
 
 The segments a-re kept in place by wedging them against the 
 sides of the pit, and filling up the interspace with earth or con- 
 crete ; thorough stanchness is secured by interposing a half -inch 
 
 strip of deal or pitch pine at 
 
 FIGS. 312 & 313. every joint, and finally driving 
 
 in wedges when all the tubbing 
 is fixed. Water coming in from 
 the surrounding strata is al- 
 lowed to escape through the 
 central hole of each segment. 
 A cast-iron lining cylinder 
 (Figs. 312 and 313) is thus 
 built up inside the shaft until 
 an impervious stratum above 
 the water-bearing ground is 
 reached; another wedging curb 
 then completes the tubbing. 
 The joints are wedged up as 
 tightly as possible, and finally 
 plugs are driven into the cen- 
 tral holes of the segments. If 
 the work has been properly performed, the lining will be water- 
 tight. The tubbing is sometimes put in by a succession of com- 
 paratively short sections, each resting upon its own wedging curb, 
 and shutting off a portion of the water-bearing beds. If this 
 method is pursued, each separate section is continued upwards to 
 the next wedging curb above, resting upon a bracket of rock ; 
 this is cut away very carefully in small sections, and the last 
 ring of segments made to join it ex-ictly. When the amount of' 
 
 LLl 
 
 I I ' I 
 
 i\ 
 
SUPPORTING EXCAVATIONS. 271 
 
 water is not excessive, it is usual to sink through the whole of 
 these strata before setting a wedging curb and fixing the seg- 
 ments.* 
 
 In a few cases no temporary lining is used, and the segments 
 are at once inserted in descending order, each ring hanging from 
 the one above it. After several rings have been so fixed, a 
 bearing-ring is put in and the wedging of the joints proceeded 
 with. This process is repeated until strata are reached which 
 require no such lining. 
 
 SPECIAL PROCESSES. The amount of water met with 
 has been sometimes so great as to render sinking by the ordinary 
 methods quite impossible, on account of there not being room 
 enough in the shafts for fixing pumps sufficiently large to cope 
 with the enormous feeders of water, and even where pumping is 
 possible the expense may render it out of the question. A few 
 figures quoted by Mr. Bainbridge t will give some idea of the 
 enormous cost due to water-bearing beds. In Germany the sink- 
 ing of a pit, only 239 feet deep, cost ,96,000, and occupied 40 
 months, although the quantity of water pumped was only 606 
 gallons per minute. For another pit the corresponding figures 
 were 570 feet, ^140,000, 91 months, 2200 gallons. Taking 
 eleven cases, it appears that the cost varied between 36 and 
 ^245 per foot of sinking, and that the average rate at which the 
 sinking progressed varied from 3-9 to 17-2 feet per month. 
 
 For dealing with cases of this kind, there are three principal 
 methods of sinking which deserve special mention : (i) Kind- 
 Chaudron or boring method; (2) Triger or compressed air 
 method; (3) Poetsch or freezing method. 
 
 Boring Method. Kind's process as improved by Chaudron 
 consists briefly in boring out the shaft by means similar to those 
 employed for searching for mineral, and then lowering into the 
 pit so formed a watertight lining of cast-iron, which can be made 
 stanch at the bottom even under water. The great advantage of 
 this process is that there is no pumping at all until the operations 
 of sinking and lining are complete ; and then, indeed, it is only the 
 contents of the shaft itself that have to be drawn up. 
 
 The various stages of the process are as follows : 
 
 (1) Alternately boring a small pit in advance, and enlarging it 
 by a bigger tool to the full size of the shaft. 
 
 (2) Preparing a seat for the moss-box. 
 
 (3) Lowering the water-tight lining (tubbing) with its moss-box 
 at the bottom. 
 
 (4) Putting in the outside lining of concrete. 
 
 (5) Pumping out. 
 
 This process has been frequently described at great length, and 
 persons who require more details than can be given in a general 
 
 * Fainbrir'pp, ilrirffm. f Tlndfm. 
 
272 
 
 ORE AND STONE-MINING. 
 
 FIG. 314. 
 
 text-book will do well to consult the original papers mentioned 
 
 below.* 
 
 The preliminary pit is bored 4 or 5 feet in diameter, and is 
 
 always kept well in advance of the full-sized shaft, generally from 
 
 30 to 100 feet. 
 
 The tool used is a composite borer with fourteen cutting chisels a 
 
 fixed in round sockets (Fig. 314). Above the chisels there is 
 the cross-piece b, with two cutters, which serve 
 to trim off any slight irregularities ; at the same 
 time it acts as a guide, and so tends to ensure the 
 verticality of the hole. There is also a second 
 guide c above it, without teeth. The total weight 
 of this tool is from 7 to 8 tons. It is suspended 
 from a series of pitch-pine rods, each 58 to 59 feet 
 in length. Some used in Belgium were 7| inches 
 square. Those used at Marsden were only 5 inches 
 square. At each end of the rod an iron fork is 
 clamped and bolted on, terminating in a taper male 
 or female screw. The top rod is connected to a 
 strong chain hanging from one end of a huge hori- 
 zontal wooden beam. The other end of the beam is 
 attached by a chain to the piston of a vertical steam 
 cylinder. When steam is admitted on the top of 
 the piston, the rods and tool are raised, but as soon 
 as the engine-man opens the valve which lets the 
 steam escape, the rods and tool fall by their own 
 weight, and the rock is chipped at the bottom of 
 the hole. Two methods have been employed for 
 avoiding the injurious vibrations of the rods which 
 would occur if there were a rigid connection be- 
 tween them and the tool. One is a sliding joint 
 
 similar in principle to that of Oeynhausen; the other is some 
 
 free-falling arrangement, such as the catch actuated by a disc, 
 
 which has already been described (Fig. 122). 
 
 The rods are turned in the usual way by a tiller, and they can 
 
 be lowered, as the hole is deepened, by a screw similar to that used 
 
 in small borings. 
 
 The mud and fragments produced in boring are cleared out 
 
 by a sludger ; that is to say, a hollow sheet-iron cylinder provided 
 
 with semicircular flap-valves at the bottom. The sludger is 
 
 sometimes worked by the rods and sometimes by a rope, which 
 
 * Chaudron, " Precede Kind. Travaux executes en Belgique," Annales 
 d<x Alines, 5 e Serie, tome xviii. pp. 435 et *eq. ; Smyth, " On the Sinking of 
 Pit Shafts by Boring under Water, as practised by Messrs. Kind & Chau- 
 dron," Trans. N. E. Inst. M. Eng., vol. xx., 1871, p. 187 ; Bainbridge, "On 
 the Kind-Chaudron System of Sinking Shafts through Water-bearing 
 Strata, without the Aid of Pumping Machinery," Proc. Inst. C.E., vol. 
 xxxiv., 1871-72, p. 43; Daglish, "On the Sinking of Two Shafts for the 
 Whitburn Coal Company," Proc. Inst. C E. t vol. Lxxi., 1882-83, p. 178. 
 
SUPPORTING EXCAVATIONS. 
 
 273 
 
 FIG. 315. 
 
 passes over a pulley at the top of the boring tower, and is coiled 
 on a drum set in motion by a special steam-engine. 
 
 When a small shaft has been cut out in this way, either for 
 part or the whole of its depth, the work of enlarging may com- 
 mence. The enlarging tool is a huge composite borer (Fig. 315), 
 with twenty-eight cutting chisels, weighing i6j tons; in the 
 centre it has a projecting loop of iron a, which 
 fits loosely into the small shaft, and serves as 
 a guide. The chisels are arranged so as to 
 make a sloping cut, in order that the sludge 
 and chips may pass down easily into the inner 
 pit. 
 
 In some cases the ordinary sludger is em- 
 ployed for clearing out this hole, but arrange- 
 ments may be made for catching the debris 
 in a special bucket, which is either placed 
 at the bottom of the hole, or is hung from a 
 little ledge cut for the purpose. When it is 
 supposed that it is full, the boring rods are 
 lowered and the bottom one screwed on to it. 
 This operation might appear somewhat diffi- 
 cult, but by providing the female screw at 
 the end of the bottom rod with a funnel- 
 shaped bonnet, it is guided into its proper 
 course over the male screw on the sludger 
 bucket, and the necessary connection is 
 easily made. 
 
 The shaft is thus sunk to the required 
 depth, which must previously have been 
 ascertained by a small borehole. When 
 therefore it is known that a bed suitable 
 for a foundation below the water-logged 
 strata has been reached, a seat is prepared by boring very 
 carefully with the chisels arranged horizontally. The seat is 
 scraped with a special tool, so as to clear off any stones, and the 
 tubbing can now be lowered. The scraping claws can also be 
 used just before the tubbing touches the bottom, as they will 
 pass through the central equilibrium pipe which will be de- 
 scribed immediately. The tubbing is made of rings of cast-iron 
 joined by bolts through their internal flanges. A thin strip of 
 sheet lead is put in the joint so as to make it stanch. The flanges 
 are all faced in a lathe in order to secure not only a watertight 
 joint, but also the perfect verticality of the whole column. At the 
 very bottom there are two rings with flanges turned outwards, 
 and the upper is capable of sliding down over the lower. The 
 space between the two outer flanges is filled with moss, which is 
 further kept in place by a net. Lastly, just above this moss-box, 
 as it is called, a dish-like bottom is bolted on, carrying a central 
 
 s 
 
274 
 
 ORE AND STONE-MINING/ 
 
 pipe which can be lengthened as the tubbing descends. The pipe 
 is called the equilibrium tube. 
 
 The whole arrangement is best understood from Fig. 316.* B is 
 the bottom ring carrying the moss outside it ; A is the ring which 
 can slide down over it telescopically ; G is the close bottom of the 
 column of tubbing, H the equilibrium tube, I the space between 
 
 FIGS, 316, 317 & 318. 
 
 CNLAROEO SECTION 
 
 SMLTIUS 
 
 the tubbing and the sides of the shaft. The column is lowered 
 into the shaft by means of six iron rods, to which lengthening 
 pieces are added as required. The top part of each suspend- 
 ing rod is a strong screw, 13 feet long, working in a big 
 nut on a frame above the shaft. The screwed rod, attached by 
 a swivel to the rod below, can be turned round by a little winch. 
 After a new ring has been put on, men at these six little winches 
 lower the column slowly ; but the whole weight of the column 
 
 * Daglish, op. eft. 
 
SUPPORTING EXCAVATIONS. 275 
 
 does not come upon the screws. The watertight bottom G causes 
 the tubbing to displace so much water in the shaft, that the whole 
 column could be made to float if necessary. Such buoyancy would 
 be inconvenient ; and it is desirable that the column should be 
 made heavy enough to sink down of itself when the screws are 
 worked. The necessary excess of weight is obtained by tapping 
 the equilibrium pipe, and allowing a certain amount of water to 
 flow into the annular space around it. The column weighted in 
 this way finally arrives at the bottom of the pit, and the broad 
 flange of the ring B rests on D as shown. When the lowering 
 is continued, the ring A slides down over B, which is stationary, 
 and the flange C compresses the moss lying in the moss-box, 
 .squeezes it outwards against the sides of the shaft and makes a 
 watertight joint (Fig. 317). 
 
 The next operation is filling up the annular space outside 
 the tubbing with cement or concrete. The cement used in cer- 
 tain cases was a mixture of hydraulic lime with sand and trass. 
 It is lowered in special boxes so constructed that their contents 
 can be discharged when they have reached any required position. 
 After ample time for hardening has been given, the water is drawn 
 out of the shaft by a bucket ; the dish-like bottom is now taken 
 off, and the joint made by the moss-box can be examined. Even 
 when this joint seems perfectly good, it is thought desirable by- 
 some to take the additional precaution of putting in a wedging 
 curb in the ordinary way a little below the moss-box (Figs. 317 
 and 3 1 8); a few rings of ordinary segmental tubbing are then 
 built up in the interval. A careful joint is made, and the shaft 
 is looked upon as permanently secure. 
 
 The advantages of the Kind-Chaudron process, which are 
 enumerated at length in Sir Warington Smyth's paper, may be 
 briefly summed up as follows : safety, economy and speed. 
 . During the last few years several modifications of the original 
 Kind-Chaudron process have been introduced with success. At 
 Gneisenau near Dortmund all tubbing above the level of the 
 water-bearing measures was discarded. A column of tubbing, 
 closed at the top as well as at the bottom, and somewhat longer 
 than the height of the watery strata, was lowered into the shaft ; 
 and in order to overcome its buoyancy a sufficient amount of water 
 was let into it by a valve, worked by a rod reaching to the surface. 
 When the moss-box had been compressed by the descent of the 
 column, cement was lowered into the annular space, along special 
 guide-ropes extending from the bottom ring but one of the 
 tubbing to the top of the pit. This plan enabled the boxes to be 
 sent down and drawn up more speedily than would have been the 
 case if they had been loose. After all owing sufficient time for the 
 complete hardening of the cement, the water was drawn out of 
 the pit, and a regular wedging curb was put in above the column 
 of tubbing and its protecting jacket of cement. 
 
2 7 6 
 
 ORE AND STONE-MINING. 
 
 This method of doing the work saved 190 yards (174 m.) of 
 tubbing at the top of the pit, and the gain in money was estimated 
 
 at ^75- 
 
 At the present time the moss-box seems to be losing much of 
 the prestige which it formerly possessed, and French engineers 
 are content to rely solely upon careful cementing for a water-tight 
 joint at the bottom of the tubbing. A shaft was successfully 
 sunk a few years ago by the " Compagnie de 1'Escarpelle " in the 
 North of France without using either moss-box, equilibrium 
 
 / 2 34 S 6 7 8 9 /O // 12 /3 /* 16 /6 
 
 Cm. iOO SO 
 
 SMtracs. 
 
 A, Green clayey marl, very plastic and impermeable (Dieves 
 vertes). B, Small boring. C, First ring of tubbing, with strong 
 shoe, weighing 12 tons. D, Second ring of tubbing. E, King 
 bolted to a flange of D. F, False bottom bolted to E. G, Man- 
 hole cover. H, Concrete. The rings of tubbing are joined to 
 each other by sixty bolts, and the upper and lower flanges are 
 strengthened by brackets midway between the holes. These 
 brackets have been omitted in the figure for the sake of clearness. 
 
 tube, or the subsequent wedging curb and false tubbing; and 
 the Lievin Company in the same colliery district, when sinking 
 two shafts in 1891-92, likewise decided to dispense with all the con- 
 trivances peculiar to the Kind-Chaudron method. The process of 
 sinking was very much simplified. They bored the shaft in two 
 operations : a first pit 2 metres (6ft. 6in.) in diameter was carried 
 down some ten or twelve metres beyond the actual depth required, 
 and it was then enlarged by a second tool, 4-90111. wide, to the full 
 
SUPPORTING EXCAVATIONS. 277 
 
 diameter of about 501. (i 6ft. 5in.). This plan obviated all difficulty 
 due to a tooth dropping from the large borer it had simply to be 
 scraped into the small shaft and was left at the bottom until the 
 completion of the tubbing. In the Kind-Chaudron process of 
 boring the small and the large shaft alternately, it would have 
 been necessary to fish up the tool before the smaller shaft could 
 have been sunk any farther. On reaching the required depth 
 the teeth of the large borer were fixed so as to cut a horizontal 
 seat, which was then scraped clean with an S like tool for 
 the reception of the tubbing. The bottom ring was made 
 with a shoe (Fig. 319), and was calculated to leave an annular 
 space 14 inches (35 cm.) wide for cement, and the huge column 
 with its watertight base was built up and lowered without any 
 equilibrium tube. It floated like an enormous boat and was 
 weighted with water so as to sink as required. After it had 
 been very carefully brought into the centre of the pit, the concrete 
 was lowered in specially contrived boxes which deposited it 
 automatically on reaching the bottom. The successful result of 
 these sinkings has justified the procedure of the Lievin engineers ; 
 they are of opinion that, in any future sinking, time might be 
 saved by doing the boring in three operations instead of two. 
 
 The following facts* relating to one of the pits lately sunk by 
 the Lievin Company (No. 4 bis) show the rapidity with which 
 the work can be carried out. Boring with the small tool began 
 on the ist of November 1891, and was stopped on the i4th of 
 January 1892, when a depth of 111*71 m. (122 yards) had been 
 reached. The large tool was set to work on the i6th of January, 
 and by the 7th of June following the pit had been bored to the 
 depth of 100 metres (109 yards). A week was then occupied in 
 cleaning the bed, taking down the boring plant, and making 
 preparations for putting in the tubbing. Beginning on the 
 1 4th of June, the lowering of the tubbing was finished on the 
 29th; it took three days to get the column into position and 
 make it rest properly upon its seat, and three weeks to put in the 
 concrete. After spending ten days in taking down the boring 
 shed and plant, the engineers were able to begin drawing out the 
 water on the 2nd of August, and they finished on the 7th. The 
 false bottom was brought up on the 8th of August, and prepara- 
 tions were at once made for continuing the sinking in the ordinary 
 way. The sinking was recommenced on the 3oth of August. 
 
 Compressed Air Method. Sinking by the aid of compressed 
 air came into notice after a successful application of this method 
 by M. Triger in France about half a century ago. In this 
 method a cylinder of cast-iron, made up by adding ring after ring 
 at the surface, like a column of Chaudron's tubbing, is caused to 
 sink gradually by the earth in the bottom being worked away ; 
 
 * Kindly furnished by M. Desailly, the engineer in charge. 
 
278 ORE AND STONE-MINING. 
 
 and in order to prevent the water in the surrounding beds from 
 coming in, air under pressure is led into a chamber at the 
 bottom of the cylinder, which is shut off by a horizontal partition 
 or diaphragm. Above this working chamber there is an " air 
 lock," that is to say a closed space in the cylinder, with trap 
 doors above and below. The two doors are never open at the 
 same time. A man going down to his work^ passes into the 
 middle chamber by the trap door, which is then closed ; the lower 
 trap door is now opened, and the man can descend into the 
 working chamber. When he goes up, or when the bucket has 
 to be drawn out, there is always this break of the journey, in 
 order to prevent the working chamber from communicating 
 directly with the atmosphere. Sinkings by this process have 
 been made since Trigger's time in various places, among others at 
 Bettisfield colliery in North Wales,* though in this case the 
 arrangements were not exactly the same as those originally 
 employed in France. 
 
 There are two great disadvantages coupled with this method: 
 
 (1) The impossibility of going to a depth much exceeding 100 
 feet, because, speaking generally, a pressure of 45 Ibs. per square 
 inch, or three atmospheres above the normal pressure of the 
 atmosphere is about as much as men can stand. 
 
 (2) The fact that the health of the men has been found to 
 suffer from such an atmosphere. In all cases it appears advisable 
 to avoid the sudden changes of pressure, and therefore invariably 
 to make a little stay in the air-lock before going up or down. 
 
 Freezing Method. The solidification of watery strata by cold 
 may be effected naturally or artificially. In Siberia,t when sink- 
 ing shallow exploratory pits through watery strata in search of 
 auriferous alluvia, advantage is taken by prospecting parties of the 
 severe cold to let Nature form protecting walls of frozen ground. 
 
 In Western Siberia the process is as follows : Towards the end 
 of the summer, square pits about 6 or 7 feet on the side are sunk 
 as deep as possible without penetrating into the watery beds. 
 The men then prepare log-huts, as dwellings for the winter, and 
 lay in good stocks of firewood. After the first frost the snow is 
 cleared out of the pits, and also from off the ground for a space 
 several yards in diameter round the tops, in order to let the cold 
 penetrate more freely. As soon as the ground is thoroughly 
 frozen, the sinking is begun by a kind of fire-setting. Billets of 
 wood are laid crosswise on the bottom of the ground and lighted. 
 The fire thaws the ground for a short distance, and the workmen 
 have to be careful that the heat does not penetrate too far, and 
 so let in the water from the unfrozen strata a short distance be- 
 
 * Lupton, discussion on Mr. Daglish's paper, "On the Sinking of Two 
 Shafts at Marsden," Proc. Jnst. C.E., vol. ixxi. 1892-93, p. 197, with figure. 
 
 t Helmhacker, " Ueber das in Sibirien iibliche Abteufen von Schurf- 
 schiichten im schwimmenden Gebirge," . u. h. Z,, 1891, p. 88. 
 
SUPPORTING EXCAVATIONS. 
 
 279 
 
 low line i, i, representing the junction of the frozen with the 
 unfrozen ground (Fig. 320). 
 
 The workmen with pick and shovel remove the softened portion 
 (a), and so deepen the shaft by some 4 to 6 inches. It is then left 
 for two or three days to freeze again, when the junction between 
 frozen and unfrozen ground is carried to 2, 2 ; a second fire 
 softens the part (b) which is removed, and then another exposure 
 to the frost for two or three days makes the ground solid to 3, 3, 
 when the part (c) can be softened and taken out. 
 
 FIG. 320. 
 
 *2WJ%^/&/^ 
 
 The alternate processes of freezing and thawing are repeated 
 every three or four days, and each time the shaft is deepened 
 from 4 to 8 inches. As the auriferous bed is approached, samples 
 are washed from time to time to see whether there is any gold, 
 and when the stratum containing the precious metal is reached 
 (Fig. 321), all the earth is carefully washed and the amount of 
 gold noted. Judging by results of similar undertakings in the 
 district, it is possible to say whether or not it will pay to work 
 the alluvium. In both figures, A represents the bed rock, B the 
 stratum of gold-bearing gravel, C overlying gravel containing little 
 or no gold, D timbering at the top. The hatching denotes ground 
 that is frozen. The shafts are sunk to a depth of 1 6 to 26 feet. 
 
 In Eastern Siberia the conditions are more favourable for 
 this kind of work, as the winter is longer, and therefore the shafts 
 
2 8o 
 
 ORE AND STONE-MINING. 
 
 can be sunk deeper. But the principal advantage lies in the fact 
 that much of the ground is eternally frozen ; here the thawing 
 can be carried on without any stoppages, and less care is neces- 
 sary, save when the underlying unfrozen strata are reached. 
 These have to be treated by alternate freezing and thawing as in 
 Western Siberia. As a rule, however, the ground is eternally 
 frozen for the whole thickness of the alluvium down to the bed 
 
 Fio. 321. 
 
 
 rock. Exploratory pits are sunk in Eastern Siberia to a depth 
 of 85 feet (26 m.) by this method. 
 
 Shafts are even put down in shallow rivers to see whether their 
 beds are gold-bearing. In autumn, when the water is shallow, a 
 set of frames, like shaft frames, 6 or 7 feet square, is lowered till 
 it touches the bottom, whilst the top is above the level of the 
 stream. It is filled up with stones, and loose stones are placed 
 around it. When winter sets in, the river freezes, and the cor- 
 tents of the box gradually become hard. A first layer of stones 
 is then worked out with the pick, and the frost allowed to pene- 
 trate downwards. Another layer of stones is taken out, and 
 again there is an interval for freezing. By repeating this pro- 
 cess the contents of the box are removed little by little, and at 
 last the river bed is reached and allowed to become hard and 
 solid from the cold, whilst at the same time the water in the 
 interstices between the outer stones has been congealed, and has 
 
SUPPORTING EXCAVATIONS. 281 
 
 formed strong protecting walls of icy conglomerate. Further 
 bin king is now carried on as in Western Siberia. 
 
 In some cases the wooden box is dispensed with, and when 
 the river is covered with a thick coat of ice, the prospector cuts 
 out a space a few inches deep of the size of the shaft. The 
 removal of a part of the ice at the top allows the cold to be 
 felt further down, and the ice becomes thicker underneath. 
 Another slice is taken off the top and again the cold penetrates 
 further, and in proportion as the top is removed the bottom re- 
 ceives coat after coat of new ice. By successive thickenings the 
 ice finally reaches the river bed, and the prospector can then pro- 
 ceed by the West Siberian method. 
 
 Poetsch's artificial freezing process consists in causing a very 
 cold liquid to circulate in pipes through the ground, and so con- 
 vert it into a solid mass, in which an excavation can be made 
 without timber or other supports. While the ground is kept 
 frozen some form of watertight lining is put in, sufficiently stanch 
 to keep out the water when the cold-producing appliances are 
 removed. 
 
 Poetsch employs a Carre machine for generating cold. Anhy- 
 drous ammonia gas is liquefied by compression in suitable pumps, 
 and the liquid which leaves at a temperature of 102 F. (38 C.) is 
 cooled by passing it through pipes surrounded by cold water. 
 The cold liquid ammonia is then made to flow into a long series 
 of pipes, placed in a large wooden tank containing a solution of 
 chloride of calcium. The liquid ammonia expands into gas in 
 these pipes, and extracts heat from the solution surrounding them 
 to such an extent that the temperature of the contents of the 
 tank is brought down to 8 or 9 F. ( - 13 C.) The ammonia gas 
 is returned to the compressor to be again liquefied and utilised 
 for the production of cold. 
 
 The refrigerating solution of chloride of calcium is pumped 
 from the tanks into a main, which leads it to a series of pipes, 
 placed in boreholes arranged in a circle around the top of the 
 proposed shaft. The pipes are double, that is to say, there is 
 an inner small pipe i^ or 2 inches in diameter for the down- 
 ward journey of the cold solution, and an outer one 4^ to 7 
 inches in diameter, carefully closed at the bottom, by which the 
 solution ascends and does its cooling work on the way. When it 
 reaches the surface it returns to the cooling tank, and is again 
 refrigerated. The process is, therefore, continuous, the ammonia 
 and the chloride being used over and over again. The nature of 
 the freezing-tube will be evident from Fig. 322 * ; a is the large 
 outer pipe connected to another, m, by the piece,/; n is a small 
 
 * Poetsch, " Ueber die verbesserte Ausfuhrung des Gefrierverfahrens 
 beim Scbachtabteufen und Streckenbetrieb," Der iv. allgemeine Bergmanns- 
 tug in Halle [/SuaZej. Fextlericht und Verhandlunyen. Halle, 1890, p. 119, 
 and Plate x. 
 
282 
 
 ORE AND STONE-MINING. 
 
 inner pipe, and the arrows show the course of the solution. The 
 supply of chloride is taken from a circular pipe at the top, fed 
 
 FIG. 322. 
 
 FIG. 323. 
 
 \V^ 
 
 r -SN 
 
 c 
 
 
 IEPOSIT TO 
 
 
 BE WORKEI 
 
 from the main, and in like manner the solution ascending the 
 various pipes is collected by another ring and led back to the 
 cooler. The particular pipe shown in the figure is destined for 
 the case of a sinking, in which the upper part, m } is in strata that 
 
SUPPORTING EXCAVATIONS. 283 
 
 do not need to be frozen. The letter JP represents a jacket made 
 of some bad conductor, to prevent the solution from becoming 
 warmed unnecessarily in its ascent. 
 
 In sinking through ground consisting of watery strata alternat- 
 ing with dry measures, Poetsch advises the following method 
 of procedure. A (Fig. 323) represents dry ground through which 
 the shaft has been sunk and timbered in the ordinary way; 
 B indicates watery beds where tubbing is necessary. Poetsch puts 
 in first of all a circle of holes, a a, round the outside of the shaft, 
 and a smaller circle b 6, around the inside. When these latter have 
 frozen the ground adjacent to them, the still smaller circle of holes 
 b 6, are bored and fitted with refrigerating tubes j as soon as 
 the ground about them has become converted into a solid pro- 
 tecting wall, the shaft is sunk with a reduced diameter, until the 
 dry strata, C, are pierced. On reaching ground suitable for the 
 wedging curb, the tubbing is built up in the ordinary way ; the 
 parts b b are cut away, and by this time the freezing has become 
 so complete at a that there is no danger of the walls falling in. 
 
 In this process there is a risk of failure, or at all events of 
 trouble, if there is any escape of the freezing solution from the 
 pipes, because the ground impregnated with it would be uncon- 
 gealable. Gobert proposes to overcome this difficulty, and at the 
 same time to make the method more economical, by sending 
 down anhydrous, or all but anhydrous, ammonia, and allowing 
 it to vaporise in the tubes, instead of circulating a refrigerating 
 solution, Intense cold is thus produced at the very point where 
 it is required, and the ground is frozen. The ammonia gas is 
 drawn out by a pump, and after having been reliquefied by pressure 
 is used over again. Gobert claims for this process that both the 
 original outlay for plant, and the subsequent running expenses, are 
 considerably reduced. He has also been led by his experience to 
 introduce improvements in the joints of the freezing pipes, with 
 the object of ensuring absolute freedom from leakage, and of 
 making the line of pipes quite flush outside, so as to facilitate their 
 withdrawal at the end of the sinking. 
 
 It has been proposed* to inject powdered cement, by means of 
 compressed air or steam, into watery strata, and so consolidate 
 them sufficiently to render the sinking of a shaft a matter of no 
 great difficulty. 
 
 The Haase Process,! for sinking through quicksands, consists 
 in forcing down a set of wrought-iron tubes around a circular 
 or rectangular area destined for the shaft. The narrow inter- 
 spaces between the tubes are closed by angle-iron and T-iron 
 riveted on longitudinally, which form a joint permitting vertical 
 motion and stanch enough for the work in question. Water forced 
 
 * Colliery Guardian, vol. bd. 1891, p. 1089. 
 t Zeitschr. f. B.~ II.- u, 8.- Wesen, vol. xxxvii. 
 
 1889, p. 204. 
 
2 3 4 ORE AND STONE MINING. 
 
 down a hollow boring rod in the middle of each tube loosens the 
 sand and carries it up to the surface. The tube can then be 
 driven down by a screw-jack or an hydraulic press. The tubes 
 are carefully guided in order to ensure a strictly vertical path ; 
 and as soon as they have been forced down into hard or compara- 
 tively hard rock, the quicksand can be excavated, for the iron 
 lining prevents any influx from the outside. 
 
 Instead of iron tubes, Haeuser* employs sheets of corrugated 
 iron, with tongues riveted on so that the bottom of each sheet 
 is held by the top of the one below. Like the Haase tubes, the 
 sheets are forced down with a strong screw-jack. Another plan 
 adopted by Haeuser consists in making the protecting shield of 
 pieces of flat iron 6 inches wide ; each " lath," if it may be so 
 called, is connected to its neighbour by a longitudinal groove 
 formed by riveting on two strips of iron. 
 
 * Herold, " Das Schacht-Abteufen im schwimmenden Gebirge mit Haase' 
 schem und Haeuser' schem Verfahren beim Braunkohlenwerk 'Zwenkau ' in 
 Zwenkau," Jahrb.f. d. B.- und H.- Wesen i. K. Sachsen, 1891, p. 27. 
 
CHAPTER VI. 
 
 EXPLOITATION. 
 
 Classification of methods of working (i) Open works of all kinds, 
 including hydraulic mining. (2) Excavation of minerals under water. 
 (3) Extraction of minerals by wells or bore-holes. (4) Underground 
 workings. 
 
 THE methods of working mineral deposits may be naturally 
 arranged into two great classes viz., open works, in which the ex- 
 cavation is open to the sky ; and underground works, in which the 
 miners perform their labour in chambers or passages under a cover 
 of rock or earth, and in which they usually need artificial light. 
 But there are in addition two other classes of workings, used in 
 comrjaratively exceptional cases, which require a place in any com- 
 plete classification. Gold-bearing gravel and phosphates are occa- 
 sionally dredged up from river-bottoms ; and liquid, gaseous, or 
 soluble minerals can be got by wells or bore- holes. Consequently 
 it is necessary to subdivide the subject into four heads : 
 
 1. Open works of all kinds, including hydraulic mining. 
 
 2. Excavation of minerals under water. 
 
 3. Extraction of minerals by wells or boreholes, 
 
 4. Underground workings. 
 
 OPEN WORKS. Some minerals are always obtained in this 
 way ; others are worked open before regular underground mining 
 begins; and, thirdly, it often happens that underground and 
 surface workings are both being carried on simultaneously in adja- 
 cent parts of the same mine. Among the minerals worked open- 
 cast are the ores of copper, gold, iron, lead and tin, to say nothing 
 of all sorts of stone. 
 
 The advantages of open works may be summed up as follows : 
 
 (a) Complete removal of the mineral without any loss in the form of 
 
 pillars, 
 (ft) No expense or trouble as regards ventilation, men always working 
 
 in good air ; no danger of explosions. 
 
 (c) No expense for lighting, unless work is carried on at night, 
 (a) No expense for timbering. 
 (e) Possibility of laying out the work in larger steps or stopes than 
 
 can usually be done in underground working places. 
 (/) Easier supervision. 
 
2 86 ORE AND STONE-MINING. 
 
 On the other hand, there is usually the immense disadvantage 
 of it being necessary to remove a great deal of waste rock covering 
 the deposit, technically known as overburden. Work too may 
 be stopped by bad weather, such as heavy rain or snow ; open 
 quarrying may spoil land or interfere with roads or canals, so that 
 the benefits do not all lie with the open works. The cryolite of 
 Greenland* is worked opencast from April to December, and dur- 
 ing the rest of the year the miners are employed below-ground. 
 
 One of the simplest cases of working away a mineral is that of 
 borax in California. The efflorescence has merely to be swept into 
 wind-rows and carted away to the refining works. 
 
 The beds of nitrate of soda in Chili are worked by large blasts 
 as shown in Fig. 5/j.f A small shaft is sunk a little below the 
 bottom of the " caliche " and enlarged in order to receive a charge 
 of slow burning powder made on the works. The explosion 
 loosens and breaks up the ground over an area about twenty yards 
 in diameter. The hard overlying stratum of "costra" is then 
 easily removed, and the "caliche" is broken up into lumps, whicli 
 are taken to the lixiviating and crystallising works. 
 
 Generally the first process in an open working is the removal 
 of the overburden, and the manner in which this is done depends 
 upon the nature of the ground. 
 
 A first example may be taken from Northamptonshire, where very 
 large quantities of iron ore are obtained from beds of J urassic age. 
 Similar beds are also worked in the counties of Lincoln and Oxford. 
 
 The actual bed of ore at Cranford in Northamptonshire is from 
 8 to 12 feet thick, and the amount of overburden taken off is 
 sometimes as much as 20 feet ; when this thickness is exceeded the 
 ore can no longer be worked with profit. 
 
 The soil or " meat earth," which is from 8 inches to 2 feet deep, 
 is put aside carefully, for it has to be restored to make the surface 
 good and available for tillage. The remainder of the overburden is 
 cut away in one or more steps or " stopes," for the convenience and 
 safety of the workmen, the base of any step being usually about 
 equal to its height. The accompanying figure (324) represents 
 a pit at Kettering in Northamptonshire, in 1889, where 15 feet of 
 overburden were being removed from a 12 -feet bed of ironstone. 
 The soil having been cleared off with the shovel, the men undercut 
 the first stratum with a double-pointed pick at a and then drive 
 down a crowbar at b and another at a little distance from it. By 
 working the bars backwards and forwards they cause a big block 
 to break off along the dotted line. This crumbles in its fall, is 
 shovelled into barrows, wheeled across the planks, and tipped on to 
 
 * " Die Kryolitverarbeitung in der Eresundschen Fabrik in Kopenhagen," 
 B. u. h. Z., 1893, p. 69. 
 
 f Eobert Harvey, "Machinery for the Manufacture of Nitrate of Soda at 
 the 'Ramirez ' factory, Northern Chili," Proc. Inst. Civ. Eng. t vol. Ixxxii, 
 1884-85, p. 341- 
 
EXPLOITATION. 
 
 287 
 
 the bank. After the top has been cleared away for a few feet, the 
 next bed is treated in the same way, and then the third, until the 
 
 ironstone is reached, and laid quite bare. The ore can usually be 
 easily broken with the pick and at once loaded into small waggons, 
 holding about a ton each. Occasionally a shot is fired, in order 
 
283 
 
 ORE AND STONE-MINING. 
 
 to loosen parts that are hard. The loading is done with an eight- 
 pronged fork, so as to separate the fine ore which the smelters 
 refuse to take. If there is much fine, the ore is sifted ; one man 
 stands over a wheel-barrow holding a round sieve, with a half- 
 inch mesh, and another shovels the ore to him. The fine drops 
 into the barrow and can be wheeled away, while the coarse is 
 thrown into the waggon. The men working on the overburden 
 are paid per cubic yard, and those excavating ore are paid per ton 
 of ore placed in the trucks. 
 
 The working faces are long, in order that a large number of 
 men may be employed at one time. As surface rent must be paid 
 whilst the ground is useless, the soil is put back with the least 
 possible delay, and tillage then goes on once more upon fields which 
 have been lowered several feet. In the figure a small waggon is 
 
 FIG. 325. 
 
 FIG. 326. 
 
 shown, but in some of the pits a full-sized railway waggon is 
 brought into the cutting and loaded directly with 8 or 10 tons of 
 ironstone. When a slice i o or 12 feet wide has been removed all 
 along the face, the rails are shifted and a fresh cut taken. 
 
 The workings start, for instance, from some convenient point, 
 (Fig. 325), connected to a main railway or wharf at X, and the tirst 
 line of workings is supposed to be shown by CD, reaching to the 
 boundary of the property AB. The successive positions of the 
 working faces take such lines as CE, CF, &c., radiating out from 
 as a centre, and all the ground CDK may have been given back to 
 the farmer, before the working face has assumed the position CP. 
 
 In hard rocks the steps may be made very much higher. Thus, 
 at the great Penrhyn slate quarry, near Bangor, in North Wales, 
 the valuable slate and the valueless overburden are both taken 
 away by a series of terraces on an average 60 feet high by 30 feet 
 wide, as shown in Fig. 326. 
 
 The great opencast at Rio Tinto (Fig. 327) is a huge open pit 
 
EXPLOITATION. 
 
 289 
 
 from which the ore is got by a succession of stopes, benches or 
 terraces, 33 feet to 50 feet high. The pit is oval in shape, and 
 650 yards (600 m.) in length on the top of the ore. 
 
 FIG. 327, 
 
 A, cupreous pyrites ; B, slate ; C, porphyry. 
 
 The opencast at the Mechernich lead mine is also worked in a 
 similar manner. The Government regulations make it necessary 
 that the base of each step shall be at least 10 feet wide, so that 
 
 FIG. 328. 
 
 stuff may not roll down from one floor on to the men working 
 below. The actual width is very much more, being usually 26 feet 
 (8 m.), whilst the height is 33 feet (10 m.) 
 
 When the rock is firm enough to stand for a great height, it is 
 sometimes found convenient to take it down in one vertical slice 
 
290 ORE AND STONE-MINING. 
 
 without making a series of steps. The general appearance of 
 Mulberry mine,* near Bodmin in Cornwall, which is worked in this 
 manner, will be understood by a reference to Fig. 328. Men 
 standing at A bore and blast holes, which throw the rock to B, 
 under which a level has been driven with an opening C, usually 
 closed by a covering of timber. A waggon is run in under this 
 opening and is easily filled. 
 
 Another method is that of firing a very large blast, which 
 brings down thousands of tons of rock at a time. It is prepared by 
 
 FIG. 329. 
 
 SCALEL.i 
 
 FEE.T 10 o ">o 20 ^ EtT 
 
 ,.,,,,..,,, _ , _ | _ | _ | _ I __ I _ I - 1 
 
 METRES 10 o 10 20 30 AO so eo 70 80 MEITRE.S 
 ABC, Outline of the face of the quarry before the blast ; 
 AB'C', Outline after the blast. 
 
 driving in a tunnel at right angles to the face of the quarry and 
 making one or more chambers, which are charged with gunpowder 
 or some other explosive ; the tunnel is tamped up like a gigantic 
 shothole, and the charge is fired by a fuse or by electricity. 
 
 As an example of a blast of this kind, I take some workings 
 for building stone near Messina (Fig. 329)^ A tunnel was driven 
 into the face of the limestone quarry for a distance of 56 feet 
 and then turned off at a right angle. The chamber 
 
 * C. Le Neve Foster, "On Some Tin Stockworks in Cornwall," Quart. 
 Jour. Geol. tioc., vol. xxxiv. 1878, p. 655. 
 
 t Falangola, " Sulle grandi mine nella roccia calcarea della catem. 
 Peloritana (Sicilia) e nella roccia granitica di Baveno (Lago Maggiore)," 
 fiivista di Artiglieria e Genio, vol. iv. 1887, p. 343. 
 
EXPLOITATION. 
 
 291 
 
 so formed was lined with a quick-setting cement in order to keep 
 out any moisture, and a cubical wooden box was built up inside and 
 charged with 64 bags of gunpowder, or in all 31 cwt. (1600 kil.) 
 
 Four ordinary fuses, placed in a long box with sawdust, 
 furnished the means of firing the charge. The tunnel was then 
 filled up in the manner shown in Figs. 330 and 331. The object 
 of the slightly sinuous form of the tunnel was to increase the 
 resistance of the tamping. 
 
 The effect of the large blast was to break up and move more 
 than ico,ooo cubic yards (80,000 c m.) of rock, with the advantage 
 
 FIGS. 330 & 331. 
 
 DETAILS OF THE TUNNEL. 
 PLAN. 
 
 
 i -3.0O 
 
 2.00- 
 
 SECTION ALONG THE LINES AB.BC. 
 
 30O 
 
 1,50 \ 
 
 a, damp earth beaten in ; b, brick wall built with common mortar ; 
 c, dry stone wall ; d, wall built with a quick-setting cement ; 
 e t wall built with hydraulic lime ; dimensions in metres. 
 
 of producing less small stone than would have been the case if the 
 ordinary method of quarrying had been employed. The dotted 
 line A B' C' shows the outline of the face after the explosion. 
 
 We now come to an important class of workings, namely, recent 
 alluvial beds, such as river gravel containing diamonds, gold or tin 
 ore. The banks may be left high and dry when the river is low, or 
 the stream may be diverted and any pools drained by some simple 
 pump. The whole process of working often consists merely in dig- 
 ging up the earth with pick and shovel, and washing it on the spot 
 with a pan or batea. If there is not enough fall for discharging the 
 refuse, in places where the operations are on a large scale, it 
 becomes necessary to raise the earth by some appliance, such as 
 the hydraulic elevator (Fig. 345).* 
 
 * Rickard, "Alluvial Mining in Otago," Trans. Amer. Inst. M. E. t 
 vol. xxi. 1892, p. 445. 
 
2 9 2 
 
 ORE AND STONE-MINING. 
 
 Dams for diverting rivers are sometimes of considerable size. 
 For instance, on the Feather river, in California, there is a dam 
 80 feet wide and 50 feet high. The water is carried off in a 
 " flume" or launder, 50 feet wide and 6 feet high. 
 
 The sand of beaches is occasionally scraped up at low tide and 
 washed for gold or tin ore. 
 
 Hydraulic Mining. Under this head it is convenient to 
 include all methods of working in which water is used for breaking 
 away the ground, and not to restrict the term, as is most 
 commonly done, to the process of working auriferous gravel by a 
 jet of water under considerable pressure. 
 
 I will take some examples : 
 
 i. China Clay Workings in Cornwall.* The first operation is 
 the removal of the overburden, and a small shaft is then sunk in 
 
 FIG. 332. 
 
 A, undecompo>ed granite ; B, decomposed granite ; C, overburden ; 
 D, engine-house ; EE, EE. successive outlines of the open pit ; 
 aa, shaft ; 66, level ; d, top of upright launder placed in the 
 small shaft sunk in the middle of the decomposed granite ; 
 ee, column of pumps through which the milky stream of china 
 clay and mica is lifted to the launder, /. 
 
 the middle of the area to be worked ; the bottom is put into com- 
 munication with the surface either by an adit level, if the contour 
 of the ground is favourable, or by a tunnel and shaft (Fig. 
 332), if the contour of the surface does not permit the driving 
 of an adit save at a prohibitory cost, or if it is more convenient 
 to have the settling pits close by. The shaft has to be fitted 
 with pumps. A stream of water is led on to the decomposed 
 granite, which the workman loosens with a heavy pick; the 
 disintegrated particles are carried away in suspension to a fu>t 
 settling pit, where the coarse grains of quartz are deposited, and 
 
 * Collins, The Hensbarrow Granite District, Truro, 1878, p. 17. 
 
EXPLOITATION. 293 
 
 the milky stream then falls down the launder d, into the level 
 and either runs out naturally or is pumped up to the surface. It 
 passes on to other settling pits, and deposits first the mica and 
 then the very finely divided kaolin. 
 
 2. Auriferous Gravel The process known as " booming," * 
 practised in California, Colorado, Idaho and Montana, consists in 
 discharging the contents of a reservoir all at once on to beds of 
 auriferous gravel. The powerful stream carries away the stones 
 and dirt into wooden troughs or launders, called "sluices," and 
 leaves behind the gold on the bed-rock, or in the upper part 
 of the run of sluices. In Peru f a similar process is adopted. 
 
 By a natural transition from "booming," we come to 
 " hydraulicking," J a process in which a jet of water under 
 pressure is made to play against a bank of auriferous gravel, break 
 it down, disintegrate it, and wash it into wooden troughs, arranged 
 so as to catch the gold by means of mercury on special floors, and 
 at the same time to discharge the stones, sand and mud. 
 
 For the purpose of storing a proper supply of water, large 
 reservoirs have to be constructed, sufficiently high above the gravel 
 bank to secure the necessary amount of pressure. They are 
 formed by erecting dams across the valleys, and they are made 
 either of earth, cribs of timber, or dry rubble masonry. One of 
 the largest in California is the Bowman reservoir, with a high 
 water area of 500 acres and a dam 100 feet high, which cost 
 $151,521, or speaking roughly ^30,000. 
 
 The water is taken to the place where it is required by (T) 
 ditches (" leats," Eng.}', (2) flumes; or (3) pipes, (i) The ditches 
 are cut out on the sides of the hills, and the earth thrown out 
 serves to strengthen the lower bank. The shape most commonly 
 adopted for the ditches is a half-hexagon, or the upbank may be 
 made with an angle of 60 and the lower with 65. The gradient 
 or ' grade " varies according to circumstances from 7 to 20 feet 
 per mile. 
 
 (2) Flumes are merely wooden troughs, or " launders," as we 
 should call them in England. Figs. 333! and 334 show the 
 manner in which they are usually made and supported. In valleys 
 or canons with very precipitous sides, the flume is sometimes car- 
 ried by iron brackets let into holes bored in the rock and hung by 
 
 * California State Mining Bureau, Ninth Annual Report of the Stale 
 Mineralogist for the year ending December /, 1889, p. 122, Sacramento 1890. 
 Bowie, A Practical Treatise on Hydraulic Mining in California. New York, 
 1885, p. 81. 
 
 t Kohlmorgen, "Die Goldgruben von Carabaya in Peru," B. u. h. 
 Zeitung, 1890, p. 303. 
 
 + This account of " hydraulicking" is in the main based, by permission, 
 on Bowie's Practical Treatise on Hydraulic Mining in California, New York, 
 1885. 
 
 Taliesin Evans, "Hydraulic Mining in California," T/te Century 
 Mtujaxine, vol. xxv. 1883, p. 332. 
 
294 
 
 ORE AND STONE-MINING. 
 
 FIG. 333- 
 
 F" 
 
 iron rods (Fig. 335).* Where it is 
 possible, ditches should be put in 
 instead of flumes, because the latter 
 cost more for maintenance. They 
 also suffer more from wind, snow and 
 storms, and lastly they are liable to 
 destruction from fire. On the other 
 hand, it may be impossible in some 
 cases to put in ditches, or the ground 
 may be too hard and too porous to 
 make a ditch advisable. When 
 water is scarce, the loss by soakage 
 and evaporation is a matter of im- 
 portance. 
 
 (3) The third method of conveying 
 water is by iron or steel pipes. They 
 are useful in crossing a deep valley, 
 for they save the expense of con- 
 
 FIG. 334. 
 
 structing a very long ditch round its head, or a very high trestle 
 bridge across it. Pipes crossing deep valleys are called " inverted 
 
 * Bowie, op. cit. 
 
EXPLOITATION". 
 
 295 
 
 siphons," although the principle of the siphon in no way comes into 
 play. 
 
 The pipes are made of riveted iron or steel, and one form of 
 
 FIG. 335. 
 
 joint is shown in Fig. 336,* made tight by running in lead and 
 caulking it. The riveting may be straight or spiral. To prevent 
 rusting, the pipes are coated externally and internally with a 
 mixture of coal-tar and bitumen. Some of the pipes used for 
 conveying water in this way are 20 or even 30 inches in diameter, 
 and in such cases the thick- 
 ness of the iron is from No. FIG. 336. 
 16 to No. 14 B.W.G. 
 
 Whether brought by 
 ditch, flume or pipe, the 
 water is led to the so-called 
 " pressure-box " or " bulk- 
 head" (Figs. 337, 338, and 
 339!), a cistern situated at 
 a sufficient elevation to give 
 the jet the force it requires. 
 The cistern is strongly made, 
 and has a grating A to 
 catch floating sticks which 
 might otherwise choke the pipe. At the bottom there is a recep- 
 tacle B to receive gravel and sand, which are discharged from 
 time to time by -opening a hatch at C. 
 
 The pipe leading away from the pressure-box is similar to that 
 used for crossing valleys, and it is brought down into the 
 workings ; if it is advisable to attack the bank in two places at 
 once, the pipe is forked, each branch having its valve. The pipe 
 terminates in a nozzle from 5 to 9 inches in diameter known as a 
 
 a is a wrought-iron collar ; b, the lead ; 
 c, a nipple of sheet-iron riveted to one 
 end of the pipe d, each length havin'g 
 a similar nipple. 
 
 Bowie, op. cit. 
 
 t Bowie, op. cit. 
 
296 
 
 ORE AND STONE-MINING. 
 
 " monitor/' The monitor shown in Fig. 340 * is provided with an 
 arrangement by means of which one man can deflect it with 
 great ease. If the nozzle B is in a straight line with A, the 
 stream passes through it unimpeded ; when it becomes necessary 
 
 FIG. 337. 
 
 
 FIG. 340. 
 
 to turn the water on to another part of the gravel bank, the lever 
 C is held to the side to which the jet has to be deflected. The 
 pressure of the water in B then moves the monitor as 
 desired. 
 
 The manner of using the powerful jet of water to wash down 
 banks of gravel is well depicted in Fig. 341, borrowed from Mr. 
 Evans' interesting article. 
 
 If the gravel is cemented into a hard conglomerate, drifts 
 * Bowie, op. clt. 
 
EXPLOITATION. 
 
 297 
 
 are run into the bank ; they are charged with a number of 25!!). 
 kegs of powder, tamped up, and fired by electricity. The jets of 
 water will then do the rest. 
 
 The gravel washed down by the jets of water is led first into 
 ditches cut in the " bed-rock," and then into " sluices." Sluices 
 are large troughs or launders lying upon the ground, and paved 
 with loose blocks of wood or with stones, in order to form a 
 
 FIG. 341. 
 
 surface fit for catching the gold and the amalgam. Figs. 342, 343, 
 and 344,* show a section, elevation and plan of a sluice-box with 
 two kinds of lining ordinarily adopted. It will be seen that 
 the sluice in this case is a trough 5 feet 3 inches wide, made of 
 i J inch plank at the sides and 2-inch plank at the bottom, upon 
 which are placed blocks of wood 20 J inches square, and 13 inches 
 deep, set with the grain on end. They are separated at the 
 bottom by cross strips of wood i \ inches thick, and the sides are 
 protected by blocks 3 inches thick. At one end the paving is of 
 large stones. 
 
 The sluice is generally made in twelve-foot lengths, and the 
 inclination is commonly defined by the fall given to such a length. 
 * Bowie, op. cit., p. 222. 
 
298 
 
 ORE AND STONE-MINING. 
 
 FIG. 342 
 
 1 
 
 T~ "T" ~r 
 
 I-.^-J. L x" i 
 
 FIG. 343. '? 
 
 FIG. 344 
 
EXPLOITATION. 299 
 
 Thus it is said that the grade is 6 inches, meaning 6 inches to 
 1 2 feet or J inch to the foot. The run of sluices may be several 
 hundred or several thousand feet long. 
 
 The false-bottoms for sluices are called "riffles." The wood 
 preferred for the block-riffles is that of the " digger " pine (Pinus 
 sabiniana). Longitudinal riffles are made of poles, wooden rails 
 covered with strips of iron, or iron rails, In New Zpaland* the 
 riffles are sometimes made of transverse bars of angle-iron, riveted 
 to angle-iron or placed in a wooden frame, which enables them to 
 be reversed when worn. The sluice-boxes are lined with thin 
 sheet iron, and sacking or cocoa-nut matting is placed under the 
 riffles to assist in retaining the gold. 
 
 In order to catch its gold more effectually, the finer material 
 is taken out and treated separately in broad sluices called " under- 
 currents," at the side of the main one. A grating of bars of 
 iron, i inch apart, called a "grizzly," is fixed across the main 
 sluice, and the fine gravel and sand which drop through are led 
 to a broad, shallow, sloping box, eight or ten times as wide as the 
 sluice itself, and paved like it with stones, wooden blocks, or 
 longitudinal riffles. The finer portions of the gravel, after passing 
 over the "undercurrent" and depositing much of their gold, are 
 once more turned into the main sluice lower down. 
 
 The big boulders rushing down the sluice are of service at first 
 by breaking up gravel which is much cemented together, but at 
 the same time they naturally wear out the sides and the pavement. 
 It is therefore advisable to get rid of them, as soon as they have 
 done all the useful work they are capable of performing. This is 
 effected by arranging a "grizzly" or grating which will deliver 
 the boulders into a ravine or gully, and so dispose of them without 
 any further cost. 
 
 Mercury is added several times a day at the head of the 
 sluice; and the upper part, say, the first 1000 feet, is cleaned up 
 every two or three weeks. At the time of the clean-up the 
 washing down of the gravel bank is stopped, or the current is 
 diverted into a parallel line of sluices. A small quantity of water 
 is turned into the sluice which, is to be cleaned up, the blocks are 
 then taken out, washed, and pub on one side. All the amalgam 
 is picked up with iron scoops, washed, and squeezed through 
 canvas or leather, and the amalgam is retorted. The spongy 
 gold remaining behind in the retorts is then finally melted 
 into bars. The mercury recovered by condensation is used over 
 again. 
 
 When the bed-rock is below the drainage level, the hydraulic 
 elevator * may be employed. A jet of water under heavy pressure 
 
 * Rickard, " The Gold-fields of Otago and Alluvial Mining in Otago," 
 Trans. Amer. Imt. M. E., vol. xxi. 1892, p. 443 and 455 ; Parliamentary 
 Reports on the Mining Industry of Aetv Zealand, Well.ugton, 1891, p. 67, 
 with plates. 
 
300 
 
 ORE AND STONE MINING. 
 
 is brought by a pipe A (Figs. 345 to 348) to the nozzle B, and 
 rushes up the pipe D, producing a powerful suction in the 
 " hopper " C. The water and gravel are carried up against the 
 cast-iron striking plate S, and then run down the sluice-boxes. 
 
 FIG. 345. 
 
 Fig- 349 explains the method of using the elevator for treating 
 an immense accumulation of tailings at the Blue Spur, Otago, 
 N.Z. On the left hand side is a huge nozzle playing upon the 
 face of the tailings, 59 feet high, and washing down the gravel 
 and sand of which they are composed. To the right is the first 
 elevator, which raises the stuff 15! feet into a set of sluice-boxes, 
 und further to the right is a second elevator lifting it 56 feet 
 vertically into another run of sluice-boxes. 
 
EXPLOITATION. 
 
 301 
 
 The quantity of water used is measured by a unit called the 
 " miner's inch,"* which unfortunately is not invaiiably the same. 
 The term means the quantity of water discharged per square 
 inch of sectional area of an orifice cut through a vertical board, 
 forming one side of a box. The discharge will necessarily vary 
 with the height of the surface of the water above the orifice, the 
 thickness of the board, and the shape and nature of the orifice ; 
 as these factors of the problem are not the same in all localities, 
 it is impossible to give one definite value for the miner's inch of 
 water. The orifice is usually rectangular, but it may differ in height 
 and width. However, the quantity represented by the miner's 
 inch may be taken as varying from 2000 to 2600 cubic feet per 
 
 FIG. 349. 
 
 THE GLUE Spun 
 Otagu. .v Z. 
 
 24 hours ; in some cases the outflow is reckoned for 10 hours only, 
 and is spoken of as the " ten hours miner's inch." 
 
 Under these circumstances it is evident that great care must 
 be taken to ascertain precisely what inch is meant, before making 
 any estimates based upon this uncertain unit, the miner's inch. 
 
 The " duty " of the miner's inch is " the quantity of material 
 washed by an inch of water in 24 hours." As might be 
 expected, the duty varies very considerably, indeed from i to 4 J 
 cubic yards. The duty necessarily depends upon the pressure oJ 
 the jet of water, and upon other causes, such as " character of 
 the material washed, height of banks, use of explosives, size and 
 grade of sluices, and class of riffles. The sluice affects the duty 
 of the inch in so far as its capacity regulates the quantity 
 washed." f 
 
 Under favourable conditions at Cherokee Flat,J viz., fine 
 
 * " The Auriferous Gravels of California," Ninth Annual Report of the 
 State Mineralogist for the year ending December I, 1889 ; Sacramento, 1890, 
 p. 122 ; and Bowie, op. cit. p. 124. 
 
 f Bowie, op. cit. p. 268. J Bowie, op. cit. pp. 268, 269. 
 
3 02 ORE AND STONE-MINING. 
 
 material, high banks, head of 300 to 350 feet, and grade %, 
 5*5 cubic yards are said to be the duty of the miner's inch. 
 
 At Osceola,* in Nevada, the average washing in 1890 was r62 
 cubic yards to the inch of water and it was expected that the 
 duty would be raised eventually to 2 cubic yards. 
 
 It is hardly necessary to say that the yield of the gravel varies 
 between very wide limits, and it is consequently impossible to lay 
 down any average for the hydraulic mines of California or any 
 other country. But the accompanying table gives the results of 
 actual work, and will at all events show that poor gravel, con- 
 taining gold worth only 10 or 15 cents, say, $d. to 7^. per cubic 
 yard, can sometimes be made to pay good profits. 
 
 With the exception of Osceola, the works were all in California ; 
 the figures are borrowed from Mr. Bowie, and many other ex- 
 amples of the yield of auriferous gravel will be found in his work 
 and in Mr. Hammond's report. 
 
 A cubic yard of gravel is estimated by Mr. Hammond to weigh 
 from i J to if tons. 
 
 One of the great difficulties with which the hydraulic miner has 
 to contend is getting rid of the enormous quantities of refuse 
 produced by his washings. Some idea of these quantities will be 
 gathered from the statement that one working alone, the Gold 
 Run Ditch and Mining Company, was for a period of eight years 
 discharging 4000 to 5000 cubic yards of sand, gravel and boulders 
 daily into a tributary of the Sacramento. As a natural con- 
 sequence banks were formed in the river, obstructing the 
 navigable channels, rendering overflows more frequent and 
 destructive, and causing valuable land to be destroyed by de- 
 posits of sand. Litigation ensued, and some years ago the 
 Superior Court of Sacramento decided that the hydraulic mining 
 companies must build dams to impound the coarse and heavy 
 debris, or take other means to prevent their being washed down 
 the rivers. 
 
 The consequence of this decision was a great diminution of the 
 amount of hydraulic mining carried on in the State ; but quite 
 lately an Act of Congress has been passed which will allow work 
 to be resumed at many of the mines. 
 
 (2) EXCAVATION OP MINERALS UNDER WATER. 
 In Chapter IV. mention was made of dredges of various types, 
 which are employed for the purpose of extracting gold-bearing 
 sand and gravel from the beds of rivers. Gold is not the only 
 mineral worked in this fashion ; in South Carolina phosphate of 
 lime is dredged up from river-bottoms, and in Prince Edward 
 Island a shell-marl obtained in a similar manner is sold as a 
 fertiliser. Lastly, on the coast of Germany, between Dantzig and 
 Memel, two forms of subaqueous work are applied to the getting 
 
 * Eng. Min. Jour., vol li., 1891, p. 630. 
 
EXPLOITATION. 
 
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304 ORE AND STONE-MINING. 
 
 of amber.* Some is dredged up by bucket-dredges, and some is 
 obtained by divers. The divers go out in boats about three- 
 quarters of a mile off the Briister Ort lighthouse, and after 
 anchoring they descend to work the amber bed, being equipped 
 with regular diving dresses, and supplied with air by pumps 
 worked by their comrades. Carrying a crowbar and a pronged 
 iron, the diver searches for masses or lumps of amber and detaches 
 them from the parent bed, or finds them already loosened and 
 dislodged by storms. 
 
 (3) EXTRACTION OP MINERALS BY WELLS AND 
 BOREHOLES. Liquid, gaseous and soluble minerals are 
 sometimes obtained by one of these two methods. The principal 
 are : carbonic acid, natural inflammable gas, petroleum, and salt. 
 
 Carbonic Acid. Underground supplies are tapped by bore- 
 holes, and the getting consists simply in piping off the gas from 
 the top. 
 
 Natural Gas. Precisely the same remark applies in the case of 
 the natural gas used for fuel in Pennsylvania, the occurrence of 
 which has already been described. 
 
 Petroleum. This mineral may be got either by wells or bore- 
 holes. In the United States, in Galicia, and in the great oil- 
 district on the Caspian Sea, boreholes are sunk by one of the 
 processes described in Chapter III., and it is found that the oil 
 will either rise to the surface or part way to the surface. In this 
 latter case it has to be drawn up by pumps. In order to increase 
 the flow of oil from the surrounding rocks into the bore-hole, it 
 is usual to break up and crack the oil-bearing stratum by a 
 torpedo. This is a powerful charge of some explosive con- 
 tained in a tin cylinder, which is lowered into the hole to the 
 required depth and then exploded. Nitroglycerine, dynamite or 
 gunpowder are employed, but of course the last is only used when 
 its more powerful rivals cannot be obtained. As much as a 
 hundred quarts of nitroglycerine may be used for one blast, in 
 which case the explosive is let down in separate cylinders, each 
 containing twenty quarts. The explosion of the top cylinder fires 
 the charges in the others. 
 
 In Burmah the petroleum is got by wells, and this was the 
 manner by which the great Russian deposits were worked until 
 comparatively lately. The oil gradually oozes out of the sur- 
 rounding strata and accumulates in the bottom of the well, whence 
 it is drawn up by earthenware pots. 
 
 Salt. The great bed of salt at and near Middlesbrough is 
 worked by making a borehole and putting in two tubes and a 
 pump, so arranged that water from a superincumbent bed of 
 sandstone travels down, dissolves the salt, and is then drawn up. 
 The process pursued will be apparent from an inspection of the 
 
 * " The Amber Fisheries of the Baltic," Evening Standard, Sept 12, 1888. 
 
EXPLOITATION. 
 
 305 
 
 figure. A drive-pipe an (Fig. 350) is first rammed down through 
 the alluvial soil, in the manner described by Fig. 142, and a borehole, 
 8 inches in diameter, is put down through the sandstone, gypseous 
 marl, and the whole thickness of the rock-salt, until it has reached 
 
 FIG. 350. 
 
 Roctfsalt 
 
 Anhydrite 
 
 JSaliferous 
 Marl 
 
 the underlying anhydrite. It now has to be lined with a steel 
 tube bb (Fig. 350, in which the size of the tubes is greatly 
 exaggerated), 6| inches in diameter internally; for the first 150 
 feet from the bottom the steel is J inch thick, then T 5 F inch for 
 300 feet, and the remainder is 5 inch thick. With the sleeve 
 
 u 
 
3 o6 ORE AND STONE-MINING. 
 
 couplings over them, the tubes just pass down the drive-pipe. In 
 the rock-salt and in the 600 feet of water-bearing sandstone, 
 the lining pipe is perforated with holes i inch in diameter, and 
 1 2 inches apart vertically. 
 
 Lastly, a steel suction pipe (Fig 350, c), 3 inches in diameter 
 internally, and \ inch thick, made in 2o-feet lengths, united by 
 sleeve couplings, is lowered into the borehole; about 240 feet 
 from the surface is fixed a brass working barrel (Fig. 350, d\ 6 feet 
 long, 4 1 inches in diameter and ^ inch thick, and above it steel 
 tubes, 4 1 inches in diameter, which reach to the surface. The 
 working barrel has a ball valve at the bottom. When the pump 
 bucket, also fitted with a ball valve, has been let down by a series 
 of rods, and the last one has been connected to the end of the 
 walking beam, the extraction of brine can commence. It is 
 evident from the figure that when a pump is set in motion at d, 
 water will ascend the suction pipe, and its place will be taken by 
 water from the sandstone. This descends the outer tube to the 
 rock-salt, brings it into solution, and is pumped up as brine. 
 As the pumping proceeds, the rock-salt is gradually eaten away 
 all round the borehole ; in time the marl roof must fall in, and 
 eventually the pipes will get more or less choked, and the brine 
 will be too weak to be worth pumping. 
 
 The rate of pumping is regulated so that the brine is delivered 
 
 with 25 per cent, of salt. As it comes 
 
 FIG. 351. up it is full of gas, which is mainly 
 
 nitrogen with a small proportion of 
 
 hydrocarbons. 
 
 The boreholes are arranged in fours 
 at the corners of a square, with a 
 diagonal of 200 feet (Fig. 351). 
 
 00jt3 ~ The brine is delivered into a large 
 
 storage and settling-pond, whence it 
 flows into sheet-iron evaporating 
 pans. 
 
 a If there is no natural supply avail- 
 
 able, as is the case in the Middles- 
 brough district, fresh water from the surface is run down the 
 outer pipe, and the dissolving proceeds as before. 
 
 Natural sheets of saline water or brine can be tapped by wells 
 or boreholes in some districts ; indeed salt was worked in this 
 way in Cheshire long before the discovery of the rock-salt. Some 
 of the Cheshire salt is derived from brine pumped up from 
 inundated mines worked originally for rock-salt, which are now 
 full of water and cannot be entered. 
 
 This therefore is practically a combination of underground work 
 with extraction by solution, and the process which in these cases 
 has been finally adopted, through force of circumstanceSj is some- 
 times found advisable from the commencement. 
 
EXPLOITATION. 307 
 
 Gallon* describes and figures the method of working the salt 
 marls of the Salzkammergut by huge elliptical chambers. A 
 network of drivages is first of all made at the floor of the proposed 
 chamber, and then fresh water is brought in, until it fills the 
 excavations and gradually eats away the pillars and roof. The 
 brine is pumped up and the clayey matter falls on the floor of the 
 chamber and is left there. 
 
 At Bex in Switzerland the process is similar, only it has 
 to be adapted to the nature of the deposit worked. The salt 
 occurs in the form of large lenticular masses of saliferous 
 anhydrite surrounded by anhydrite free from salt. The lenses 
 are from 10 to 50 metres wide, and are known to extend to a 
 depth of 300 or 400 metres, dipping almost vertically. 
 
 A main shaft is sunk and the saliferous rock is reached by cross- 
 cuts and dissolved away in slices 100 metres thick at a time. 
 
 An intermediate shaft, or winze, is sunk from the crosscut, 
 and when it has reached a depth of 100 metres a second crosscut 
 is put out, from which two long drivages, 2 metres high and 
 i'5om. wide, are made in the direction of the major axis of the 
 deposit. By a series of drivages at right angles to each other, 
 the lowest part of the slice is cut up into a set of square pillars 
 about 5 or 6 metres on the side. Water is let into the winze, and 
 is allowed to rise to the level of the upper crosscut. It dissolves 
 the salt from the rock, is pumped up, piped out to the surface 
 through a long adit, and evaporated. As the strongest brine 
 sinks to the bottom, the pumps are made to take their supply from 
 the lowest part of the workings. The saliferous anhydrite contains 
 from 25 to 30 per cent, of salt, and when this has been dis- 
 solved out, the rock does not fall to pieces as might have been 
 expected. Gypsum is soluble in water containing 10 to 14 per 
 cent, of salt, so the first action of the water is to dissolve some 
 of the anhydrite ; but when the brine becomes more concentrated, 
 gypsum is deposited in the form of small crystals, which bind 
 the anhydrite into a firm mass. Consequently the leached rock 
 stands perfectly well by itself, and there is no fear of the sides 
 falling in. 
 
 One of these large workings, when once properly laid out, will 
 go on furnishing brine for thirty or forty years. The rate of 
 pumping is regulated so as to supply brine with 25 to 26 per cent, 
 of salt. 
 
 A last instance of a combination of underground workings and 
 extraction by watery solution may be taken from Parys Mountain 
 in the island of Anglesey. During the active working of the 
 Parys mine many years ago, poor copper ore which had been 
 broken, but which would not pay for the expense of winding and 
 dressing, was left underground. Under the action of air and 
 
 * Lectures on Mining, vol. ii. p. 23 ; Atlas, plate xliii. Figs. 251, 2^2, 
 
3 o8 OHE AND STONE-MINING. 
 
 moisture, the chalcopyrite in the refuse and in the pillars is 
 gradually decomposed, producing a certain quantity of soluble 
 sulphate of copper. Rain finding its way down the mine dissolves 
 the sulphate, and the pumps draw up a strongly coloured water, 
 which in contact with scrap iron yields merchantable copper 
 precipitate. The mine is now worked solely in this way. 
 
 In a like manner a little copper has been got from the water 
 flowing out of the County adit in Cornwall. 
 
 (4) UNDERGROUND WORKINGS. The methods em- 
 ployed for excavating minerals underground are almost as various 
 as the different forms in which the minerals themselves occur. 
 
 The deposit must first be reached by a shaft, or, where 
 the contour of the country permits it, by an adit. The choice 
 between these two methods of attack must be entirely governed 
 by the circumstances of the case. In a comparatively level country, 
 it would be impossible to bring in an adit capable of rendering 
 any real service without going to a distance which would make the 
 cost of driving prohibitory; but among the mountains an adit 
 may be the quickest and cheapest means of entering productive 
 ground. It has the advantage of enabling all pumping to be 
 dispensed with for a time, of reducing subsequent water-charges, 
 of affording an opportunity of easily utilising water supplies in 
 the neighbourhood, and often of bringing out the mineral to a 
 more suitable locality for treatment than could be obtained by 
 raising it perpendicularly to the surface. Instances often occur 
 in which the adit can be driven along the course of the deposit 
 itself, and so furnish valuable data concerning it. A shaft 
 sunk upon the dip of a deposit has this same advantage; but 
 here it is necessary to remark that the term " shaft " does not 
 always convey the same meaning. The ore-miner uses the word 
 to denote not only a vertical pit, but also one sunk upon a vein, 
 even if the inclination is but slight. There are portions of shafts 
 in Cornwall which do not dip more than 15 degrees from the 
 horizontal. Shafts with an inclination of 60 or 70 from the 
 horizontal are common in vein-mining, and no ore-miner would 
 think of calling them by any other name. On the other hand, 
 the coal-miner seems to confine the word shaft to vertical pits. 
 If a pit is sunk vertically till it meets a seam of coal, and is then 
 continued along the dip of the bed, the latter sloping part of the 
 excavation, even if it has a dip of 50 or 60, is called an "inr 
 cline," and not a shaft. The term " slope " is used in places to 
 denote an inclined pit along the dip of the strata. 
 
 We will suppose that the deposit has been struck by a shaft, 
 incline, or level. The problem is how to remove it to the best 
 advantage. As the conditions are so various, it is advisable to 
 classify the methods according to the nature of the deposit, and 
 treat separately the modes of working (i) beds ; (2) veins; and 
 (3) masses. 
 
EXPLOITATION. 
 
 309 
 
 FIGS. 352 & 353- 
 
 BEDS. Two great divisions stand out prominently : 
 
 (A) Methods in which the bed is cut out into pillars; and 
 
 (B) methods in which the bed is removed at once without this 
 preliminary treatment. In the former the pillars may either be 
 Jeft as permanent supports, or they may be removed in a second 
 stage of the process of exploitation. We have thus three prin- 
 cipal processes of working to consider 7 as shown in the following 
 table : 
 
 (A i.. Pillars left as permanent supports. 
 
 (. 
 A2. Pillars worked away. 
 B. Longwall working-. 
 
 Ai. Pillars Left as Permanent Supports. This system 
 is adopted with minerals of no great intrinsic value, as it is often 
 better to lose much of the mineral in the form of pillars, than to 
 go to the expense of putting in artificial supports during the 
 period of exploitation. 
 
 The method can be best understood by giving a few charac- 
 teristic examples taken from minerals 
 of various kinds viz., gypsum, iron 
 pyrites, limestone, salt, and .slate. 
 
 Gypsum. Figs. 352 and 353 repre- 
 sent in section and in plan the cham- 
 bers and pillars of the underground 
 gypsum quarries at Paris, which supply 
 the stone from which the well-known 
 plaster is made.* The principal bed 
 is from 50 to 60 feet in thickness. 
 Pillars are left 10 feet square at the m m ra Ik 
 
 1 1,1 77 1 1 j 1 EU SI Hj P$SS 
 
 base, and the stalls between them are 
 
 1 6 feet wide. The workings are slightly Hi 11 PI il 
 
 arched, and are not carried up to the 
 
 true roof, for the purpose of better maintaining the security of the 
 
 chambers, because heavy damages would have to be paid if they 
 
 " caved in " and rendered the surface useless. A similar layer of 
 
 gypsum left for the floor prevents "creep" that is to say, arising 
 
 of the floor owing to the thrust of the pillars, and enables the 
 
 underground roads to be kept in order with little expense. 
 
 In Nottinghamshire the poor parts of the bed of gypsum are 
 left as pillars, and they are sufficiently frequent to prevent any 
 waste of good rock for supports. 
 
 Iron Pyrit.es. At Cae Coch Mine, near Llanrwst in North 
 Wales, there is a bed of iron pyrites, about 8 feet thick, which 
 is worked by leaving pillars from 2 to 3 yards in diameter, at 
 intervals of 8 or 10 yards. The pillars are somewhat irregular, 
 because where the roof is firm and strong more space can be 
 
 * Gallon, Lectures on Mining, vol. ii. plate xli. 
 
3io 
 
 ORE AND STONE-MINING. 
 
 left without support. If the roof appears at all weak, the 
 pillars are made closer together. The excavations are slightly 
 arched at the top, so as to obtain a little more strength. 
 
 Limestone. A considerable quantity of limestone is wrought 
 in this country by underground mining, especially in Wiltshire, 
 Worcestershire, South Staffordshire, and Scotland. 
 
 The beds of freestone which are worked near Bath occur in the 
 Great Oolite, and vary from 8 or 9 to 1 8 or 24 feet in thickness; 
 the dip is slight, being only i in 33. 
 
 FIG. 355. 
 
 Section 
 
 FIG. 354. 
 
 --2 
 sidehole 
 
 Isidehole 
 
 I 
 
 t 
 
 /oi_ 1 
 
 \ '\- 
 
 Main heading 
 
 n side hole 
 
 The bed of stone, which it is proposed to work, is reached by 
 an inclined plane, and a main heading is driven out 15 to 16 
 feet wide, with " side holes " at right angles, as wide as the 
 roof or ceiling will admit with safety, say 20 feet to 24 feet, 
 leaving pillars 10 feet square and upwards (Fig. 354). If any 
 rock is unsound, it is left as a pillar, and this may cause some 
 irregularity in the plan of the mine. 
 
 The first process in removing the stone consists in excavating 
 the " jad," a hoiizontal groove at the top of the bed, which is 
 
 cut in for a depth of 5 feet 
 FIG. 356. and a width of 20 to 25 
 
 />/a " feet ( Fi S s - 355 and 35 6 )- 
 
 After the jad has been 
 
 excavated with the pick 
 (Fig. 355), a vertical cut is 
 made with a saw along the 
 line BA (Fig. 356), and 
 another along the line DC, 
 and a piece ABDC, called the " wrist," is wedged up from the 
 bottom or off from the side ; it breaks along the line AC. When 
 the " wrist " has been removed, the blocks are simply cut out 
 with saws. These saws are 6 or 8 feet long by 10 inches to 12 
 inches wide. The first saw used in the jad has to be narrower, 
 and is called the "razor saw." 
 
 The heaviest saw weighs 56 Ibs., and the handle can be fixed 
 
 
 \ 
 
 B 
 
EXPLOITATION. 311 
 
 as shown by the dotted lines (Fig. 156), or entirely below the eye 
 for working immediately below the roof. 
 
 When set free by sawing on all four sides, the block is easily 
 detached by wedges driven in along a plane of bedding. The 
 blocks are lifted off by cranes, and either loaded at once on to 
 trucks or stacked inside the quarry, after having been roughly 
 dressed with an axe or with a saw. 
 
 A workman can saw 15 square feet of the softest beds in an 
 hour. 
 
 In the neighbourhood of Dudley there are two beds of Upper 
 Silurian limestone worked by true mining. The top bed is from 
 1 6 to 1 8 feet thick, and it is got by a system of pillars and 
 chambers. The pillars are 8 yards square, and the stalls between 
 them 13 to 17 yards. Near the outcrop both the pillars and the 
 stalls are rather smaller than this. The top 2 feet of stone are 
 left to support the roof. 
 
 Salt. The salt mines of Cheshire * are an excellent example of 
 pillar and chamber workings. The bed is 84 feet thick, but only 
 
 FIG. 357. FIG. 358. 
 
 the bottom part, 15 to 1 8 feet thick, is mined. Pillars 10 yards 
 square are left promiscuously, about 25 yards apart, or closer if 
 thought desirable in any special places. Fig. 357 represents part of 
 Marston Hall Mine near Northwich. The bed is almost horizontal, 
 and is reached by two perpendicular shafts ; wide stalls are then 
 driven out on all sides. The workings are advanced by making 
 an excavation in the upper part called the " roofing " (a, Fig. 358) ; 
 and the lower two-thirds of the thickness worked are got by 
 blasting slanting holes. This part is called the " benching." The 
 roofing is made by holing or under-cutting by hand, or better by 
 a Walker circular saw driven by compressed air (Fig. 216), and 
 bringing away the salt by horizontal holes bored with a jumper 
 and charged with gunpowder. 
 
 The old method of working silt in Koumaniaf was by bell - 
 shaped pits, which were widened out gradually till their diameter 
 
 * Dickinson, "Keports on the Salt Districts," Reports of the Inspectors of 
 Mines for the Year 1881, p. 66. 
 
 t Notice sur la Roumanie. Exposition Universalle de Paris en 1889, pp. 1 16 
 to 119. 
 
312 ORE AND STONE-MINING. 
 
 reached 160 to 200 feet (50 to 60 m.), after which the sides were 
 carried down vertically. 
 
 Nowadays long chambers are excavated with intervening pillars. 
 A chamber is begun by driving a level 10 to 50 feet wide 
 (3 to 16 m.), and this is deepened and widened at the same time, 
 so that the sides make an angle of 30 to 45, until the full width 
 of 1 64 feet (50 m.), is attained; the excavation is then continued 
 with vertical sides. The section therefore resembles that of an 
 ordinary house. A gangway is carried round the roof for the 
 purpose of inspecting it regularly. 
 
 At Turgu Ocna Mine there are four of these chambers which 
 will eventually vary from 100 to 160 feet in width (30 to 49 m.) 
 and 450 to 560 feet (138 to 170 rn.) in length, and afford a total 
 working area of 22,000 square yards (18,550 square metres). 
 
 As regular blocks of almost uniform weight are preferred for 
 exportation, great pains are taken to get out the rock-salt in 
 the form which meets with the readiest sale, and to reduce the 
 quantity of " smalls " to a minimum. The blocks are cut by hand 
 or by machine. Three cutting machines are used : one makes 
 horizontal cuts in the direction of the long axis of the chamber, 
 the second vertical cuts, and the third transverse cuts, so as to 
 divide the rock-salt into regular cubes, about one foot on the side, 
 weighing 132 Ibs. each (60 kil.). 
 
 Slate. In the Festiniog district in North Wales the principal 
 bed is 120 feet (36 J metres) thick in places, and there are others 
 from 30 to 70 feet thick; these beds are spoken of as "veins," 
 though they are true sedimentary deposits. The dip of the beds 
 is from 20 to 30 or 35, whilst the dip of the planes of cleavage 
 is about 45; the strike of the planes of cleavage is very nearly 
 the same as the strike of the planes of bedding. 
 
 The method of working consists in making a series of parallel 
 chambers (openings) separated by pillars (walls). These do not 
 follow the dip, but run somewhat askew, because it is found 
 that the slate rends well at right angles to the cleavage planes 
 in a direction which does not coincide with the dip exactly. The 
 width of the chambers along the line of strike varies accord- 
 ing to the firmness of the bed selected as roof of the chamber, 
 and is commonly from 35 to 50 feet. The width of the inter- 
 vening piliars is usually somewhat less. 
 
 The workings are divided into a succession of floors about 50 feet 
 one below the other vertically. The first operation consists in reach- 
 ing the bed by means of an adit or an incline sunk along the dip of 
 the bed and then levels are driven out along the strike, A BC D (Fig. 
 359, plan ; Fig. 360, cross section), under some bed which offers the 
 necessary guarantee of solidity, very often an altered volcanic ash. 
 When a new level, such as D (Fig. 360), has been driven a certain 
 distance it is connected with the level above by an inclined drift 
 called a " roof." The " roof," or " rise " as it would be called by 
 
EXPLOITATION. 
 
 3'3 
 
 an ore-miner, is a passage about 4 feet high, and 4 feet wide, 
 generally excavated from below upwards, on account of its being 
 more economical to let the broken rock fall into the level underneath 
 than to draw it up by hand, which becomes necessary if the passage 
 is made by "sinking" i.e., excavating from above downwards. 
 The "roof" is usually carried up on one side of the proposed new 
 chamber. The third step in the process is the "widening," or 
 excavation of the rock on one side of the " roof," until the slate is 
 uncovered for a width of 40 or 50 feet. The result of this work is 
 the formation of an inclined open space 40 feet long, for instance, 
 along the strike, and stretching up from one level to the next one 
 50 feet above it vertically. While this work is going on, the 
 level is being prolonged ; a distance of 30, 40 or 50 feet is 
 left for the pillar, and eventually a new "roof " is put up for a 
 second chamber. 
 
 In most cases the excavation of the "roof" and the process 
 
 FIG. 359. FIG. 360. FIG. 361. 
 
 of widening go on at the same time, because it is found that the 
 atmosphere of a small passage like a "roof" naturally becomes 
 bad during work, unless it is provided with some special venti- 
 1 iting appliance, whereas if the amount of space is increased, the 
 impurities introduced into the atmosphere are spread over a 
 greater volume of air, and the evil is lessened. 
 
 This preliminary work of driving levels, " roofing up," and 
 " widening," is all done by a special set of men, known as 
 " miners," to distinguish them from the slate-getters, who are 
 called " rockmen," for slate is par excellence " the rock " in the 
 district. 
 
 The productive period of the life of a chamber now begins. 
 The first duty of the rockmen is to examine very carefully the 
 roof of the chamber, which ought to have been left perfectly 
 secure by the miners ; but as the rockmen have to work under 
 it possibly for ten years or more, they naturally are anxious to 
 feel that every chance of a fall has been prevented as far as 
 possible. In the early part of the working of a chamber, when 
 the roof is within reach, the examination can be made with ease; 
 
3 i4 ORE AND STONE-MINING. 
 
 later on when the slate has been excavated, or partly excavated, 
 long ladders are required, and the task becomes much more 
 difficult. 
 
 Having satisfied themselves and the agents that all is safe, the 
 rockmen proceed to remove, bit by bit, the huge mass of slate 
 lying between their floor and the one above it. Such a mass will 
 sometimes be sufficient to produce merchantable slate worth 
 ^10,000 or even ,15,000, and to give work to a small gang of 
 men for fifteen years. 
 
 In the plan (Fig. 359), the lines PP' are the sides of the chambers 
 and also indicate the direction of the " pillaring." When the slate 
 is taken away a large chamber is left, and the series of chambers 
 one above the other forms a huge continuous inclined opening 
 stretching down from the surface, it may be, for a distance 
 of several hundred yards. Between each two of such openings, 
 there is the supporting pillar, nearly if not quite equal in size to 
 that of the excavation. The consequence is that very nearly one- 
 half of the available slate is lost in the form of pillars ; much 
 again is entirely wasted in making the preliminary drivage, the 
 " roof," the " widening," and the " free side." There is a further 
 loss in getting the blocks and, as we shall see later on, in making 
 the<e into marketable roofing slates or slabs. Jndeed it is 
 reckoned that even a good " vein " will yield only about 40 per 
 cent, in the form of blocks, and that two-thirds of this are wasted 
 in the subsequent dressing. Therefore, the slate miner does not 
 sell more than one-tenth to one-sixth of the slate rock which he 
 lays bare in a chamber, to say nothing whatever of the loss in 
 the form of pillars, which have to be left in the mine as perma- 
 nent supports. 
 
 There are varieties of this method of working. For instance, 
 at Aberllefenny in Merionethshire,* a bed 60 feet thick, dipping at 
 an angle of 70, is worked by alternate pillars and chambers with 
 a much smaller loss in supporting rock. The pillars are from 
 24 to 30 feet long, ard the chambers 100 to 187 feet along the 
 line of strike. Indeed even at Festiniog, there are chambers at 
 Wrysgan Mine, where the roof is very strong, more than 130 feet 
 in length, whilst the pillars are only 50 feet. 
 
 At Angers, in France, the beds dip at a high angle, and the 
 underground workings are carried on like an open quarry 
 under a strong roof of slate; the floor is being continually 
 worked away in steps, and an immense open chamber is left with 
 perpendicular sides. 
 
 In the French Ardennes the beds of slate are inclined at lower 
 angles, and in this respect more resemble those at Festiniog; 
 but the pillars run indefinitely along the strike, instead of 
 approaching the line of dip. The cross-section (Fig. 361) shows 
 
 * C. Le Neve Footer, "Notes on Aberllefenny Slate Mine," Trans.fi. 
 Gco'. Sj& Curmca'l, vol. x. p. 169. 
 
EXPLOITATION. 315 
 
 these pillars AA, and the chambers between them. The 
 attack of the bed is made from below, and not from above as in 
 Wales, and the slate is removed slice after slice parallel to the 
 bedding. The men stand upon the rubbish, which finally fills up 
 the chambers completely. In the figure the upper chamber is 
 exhausted, the next one is half worked out, and in the lowest 
 only one slice has been taken off. 
 
 This method of mining is favoured by the presence of natural 
 joints, which can be utilised for forming the roofs of the chambers 
 without any cutting. 
 
 In this case the walls of the excavation are supported 
 eventually, not only by the pillars, but also by the rubbish, and 
 other instances may be found where a filling up with waste rock 
 constitutes a feature of the method of working. For instance, the 
 thick seam of carcallite or kainite at Stassfurt is worked by huge 
 chambers, between which pillars are left. The Prussian Govern- 
 ment, fearing that, in spite of wide pillars, a " caving-in " may 
 possibly occur, has ordered all the excavations to be filled up. 
 The cheapest method of doing this is by working out chambers in 
 the bed of rock-salt, lying geologically below the potash salts, 
 and using the salt as stowing. The chambers in the rock-salt 
 stand well without fear of the roof giving way. 
 
 At the Wieliczka salt mines it havS been found that the natural 
 pillars, originally supposed to afford ample support, are not always 
 capable of preventing the roof from falling, and in some places 
 they are supplemented by huge timber frames (Fig. 268), which 
 are nothing more than " cogs " or " pigsties," on a gigantic scale. 
 
 A 2. Pillar Workings with. Temporary Pillars. It is 
 naturally far more satisfactory from an economic point of view 
 to leave as little of a deposit as possible : a larger output can 
 be got from a given working area if everything is removed, and 
 it seems a pity after a bed of mineral has been discovered, and 
 after all the dead work of sinking shafts and driving levels 
 has been accomplished, to allow any of the valuable material, 
 the very object of the mining, to be left behind. We therefore 
 now come to the cases in which driving galleries and cutting 
 up the bed into pillars form only a first stage in the actual 
 exploitation. 
 
 The most important example in this country, after coal, is the 
 mining of ironstone in the Cleveland district. The bed has an 
 average thickness of about 12 feet (Fig. 43) where worked. 
 If the contour of the country is not suitable for bringing in 
 adit levels, two vertical shafts are sunk, one of which is shown 
 in Fig. 362. An almost level road, the main way, is driven out 
 with a width of 5 yards ; drivages are put out, at right angles 
 to it, at intervals of 20 yards, called bords, also 5 yards wide, 
 and at distances of 30 yards apart cross-drivages are made, called 
 walls. These are only 4 yards wide. By this system of galleries, 
 
3 i6 
 
 ORE AND STONE-MINING. 
 
 juJLJLJ 
 
 the bed is cut up into a series of pillars, 30 yards long by 20 yards 
 wide, and owing to the size of the tunnels the quantity of ore 
 got out in this preliminary stage is by no means small. When 
 the bed has been divided up in this way, the work of removing the 
 pillars begins. As a rule, the attack begins on pillars situated 
 near the boundary, so that whilst the first carving out proceeded 
 towards the boundary, the removal goes on in the opposite direction 
 viz., towards the shaft. A place or drift a b is worked across the 
 
 pillar for a width of 2 to 4 
 
 FJG. 362. yards, and then, starting 
 
 from the drift a b, the rect- 
 angle beyond it is removed 
 by drivages, called lifts, 
 
 Fometimes two in number, 
 
 1 |||>f I sometimes three, as shown 
 
 in the figure and marked 
 i, 2 and 3. It may be 
 
 _'T necessary in some cases to 
 
 leave a little of the pillar, 
 in order to keep out the 
 fallen rubbish beyond and 
 to prevent a too sudden fall 
 of roof. According to circum- 
 stances, it may be a corner 
 of the pillar that is left, or a narrow strip on one side. The 
 working place is timbered during the removal of the ironstone, 
 and when all has been taken out the timber is withdrawn and 
 the roof allowed to fall. While the lifts i, 2, 3. are being worked 
 away, another place c c? is being diiven across the pillar, which 
 is a preparation for anotl er set of lifts 4, 5, 6 ; lastly, lifts 7, 
 8, 9 are worked away, and with the exception of occasional small 
 corners or strips, the removal of the pillar is complete, and its 
 place is taken by fallen rubbish. The ironstone is got by boring 
 and blasting ; the holes are bored by hand or by machine, and 
 gunpowder is the explosive mostly used. The jumper employed and 
 the three forms of mechanical augers have already been described. 
 Varieties of this method of pillar working naturally occur, bub 
 they all come back to this main principle, when the bed is of a 
 thickness which enables it to be dealt with in one operation. 
 
 As another example I will take a bed of alluvial tin ore, to which 
 I have already alluded in speaking of the sinking of a shaft 
 through mud near Falmouth (p. 268). 
 
 The bed of stanniferous gravel varied in thickness from 3 
 inches to 7 feet, but as a rule it was not thick enough for men to 
 stand upright when at work ; the maximum width was 100 yards. 
 It was reached by a shaft D sunk through the mud of the tidal 
 creek, and also by a shaft C and level AA in the hard slate 
 (Figs. 363 and 364). Main levels EE were driven in the gravel 
 
EXPLOITATION 
 
3 i3 ORE AND STONE-MINING. 
 
 bed 20 fathoms apart, and air levels GG, all strongly timbered. 
 Cross or stripping levels HH, 14 feet apart, were pushed out 
 from one air level to the other, and the gravel was removed 
 for a distance of 7 feet on each side, as shown by the shading J. 
 The mud forming the roof was allowed to fall, and fill up the 
 empty spaces. The gravel was wheeled in barrows to the main 
 levels EE, and conveyed by a railway to one of the passes FF, 
 which led to large bins, whence it could be drawn off into waggons 
 in the main rock-level A A, and sent to the shaft. 
 
 Drift mining, or the working of auriferous alluvial gravel, is 
 carried on in a similar manner. Old river beds which carry gold 
 are common in California, and especially in Sierra and Placer 
 Counties. These beds once occupied the lowest ground of the 
 district, and became covered over by true lava flows, volcanic 
 ash and mud, sometimes also by the deposition of pipeclay and 
 infusorial earth. The streams were diverted and cut themselves 
 new channels, which in process of time were so much deepened 
 as to lie many hundred feet below the level of the old buried 
 auriferous beds. The width and thickness of the old gold-bearing 
 alluvia vary greatly, as might be expected from observing the 
 bed of a river at the present day, and the gold is not uniformly 
 distributed in the gravel. The total thickness of the gold- 
 bearing gravel may amount to as much as 600 feet. In drift- 
 mining the workings are confined to the "pay-lead," usually the 
 very bottom of the channel, varying from 100 to 150 feet in width 
 on an average.* Where there is a rich gravel with $5 to $8 per 
 cubic yard, the leads may be only 50 to 75 feet wide; where 
 gravel with $2 to $4 is being mined, they are often 300 feet to 
 400 feet wide. 
 
 By tracing the junction of the underlying slate and the 
 volcanic capping (Fig. 365!), an idea is obtained of the run of the 
 ancient valley, and arrangements are made for reaching the old 
 river-bed, either by an adit driven into the hillside, or by a shaft 
 sunk from the top. Working by shafts entails the expense of 
 winding and pumping, and adits are therefore preferred. In 
 fixing a position for the adit, care is taken to start it so that it 
 will come in a little below the level of the gold-bearing gravel, 
 and so that it will afford sufficient tip-room for the waste material. 
 The adit of the Forest Hill Divide Company, Placer County, is 600 
 yards long, some others are nearly a mile in length before getting 
 underneath the old channel. When the goal has thus been attained, 
 a level is driven in the general direction of the " lead," or, roughly 
 speaking, at right angles to the first part of the adit ; the whole 
 of this work is carried on in the slate or " bed-rock," in order 
 
 * Hammond, "The Auriferous Gravels of California," California /State 
 Mining Bureau, Ninth Annual Report of the State Mineralogist, Sacramento, 
 1890. p. in. 
 
 t Ibid., plate 6. 
 
EXPLOITATION. 
 
 to save the cost of timbering and repairs, which would be 
 considerable in the gravel itself. Rises (upraises, U.S.A.) are 
 put up into the gravel bed, and, after a preliminary division into 
 
 
 I >-- U O 
 
 E/g. O 
 
 2 .& 
 
 - 
 
 n 
 
 it 
 
 3.. 
 
 - 
 
 g 
 
 fgr 
 
 
 
 RD POINT CHANNEL 
 
 ELDORADO CAMOM 
 
 blocks by a series of cross drivages, the bed is worked away. The 
 gravel is wheeled to the rises (passes, chutes, U.S.A.) leading to 
 the main tunnel, and thence drops into waggons which are drawn 
 out by horses to the surface. 
 
320 ORE AND STONE MINING. 
 
 It is reckoned in Placer County, California,* that, in the case 
 of a mine producing 250 tons (or carloads) of gravel a day, the 
 total cost of getting, tramming, washing and agency is about 
 $1.10, or 4$. 6d., per ton. The yield in this region varies from 
 $i to $10 per ton (carload,) and may be taken at $2.50 or los. 
 per ton on an average. 
 
 The method of working by temporary pillars is not confined to 
 beds of small or medium thickness. 
 
 The lead-bearing sandstone at Mechernich furnishes a good 
 example of what can be done in a rock which, though far 
 from being hard, will nevertheless allow large excavations to 
 be made without any timber. As has been already mentioned, 
 the bed of sandstone is sometimes as much as 100 feet thick. 
 Drivages are made in the bottom part of the bed, about 2 m. 
 high by 2 m. wide, and these are followed by a series of cross 
 drivages, dividing the bed up into a number of square pillars, 
 6 m. by 6 m., or 8m. by 8 m., resembling the squares of a 
 chess-board. Then, beginning at the outer part of the boun- 
 dary of the sett, the miners proceed to remove the whole of the 
 sandstone from the floor to the roof, and at last let the roof of 
 conglomerate fall in. As a rule they convert the space covered 
 by four adjacent pillars into one chamber. This is done by 
 cutting round each of the four pillars and gradually reducing it 
 in size, until at last there is an open space where the four pillars 
 stood, say a square 22 to 24 yards (20 to 22 m.) on the side, the 
 height still being the same as that of the original drivages i.e., 
 2 metres. Standing upon the broken rock, the men now attack the 
 roof, which they can often get away in layers of about 5 feet in 
 thickness, by cutting a big groove round the periphery of the 
 chamber and often putting in a suitable blast. The central part 
 will then fall in one mass breaking up as it strikes the ground. 
 A second layer is taken off and the chamber again heightened 
 5 feet. While this work is going on the roof is sounded by being 
 struck with a long pole. The miners learn by the sound given out 
 whether the rock is firm or not, and regulate their work 
 accordingly. They work upwards till they reach the conglomer- 
 ate, and having cleared out all the ore allow the roof to fall in. 
 It is important that the roof should fall in, because, as long as 
 it remains, it throws its weight upon the other adjacent pillars ; 
 but when it has come down, the pillars have only to support the 
 weight of the strata immediately above them. In the direction 
 of the dip, the chambers are sometimes made larger, and six pillars 
 are taken instead of four. With a very strong roof the chambers 
 may even cover an area of 109 yards by 43 yards (100 m. by 40 m.). 
 
 At Mechernich the workings are arranged so that the chamber 
 remains open until the last moment, the roof not falling in till 
 
 * " Bergmannische Mittheilungen von derPariserWeltaustellung,'' 1889, 
 D. u. h. Zeitung, 1890, p. 314. 
 
EXPLOITATION. 321 
 
 the completion of the process of excavation. The sulphur seams of 
 Sicily are wrought differently.* The thick beds are pierced by 
 networks of tunnels superposed one above the other, and the 
 workings are allowed to fall in. After a time, when the collapse 
 is complete, the miners make drivages in the mass of crushed and 
 broken pillars, and so reap a second harvest. 
 
 The details of the mode of procedure are as follows : When the 
 dip of the beds is less than 30, one set of tunnels is driven along 
 the strike and another set along the line of dip. The tunnels are 
 made 8 to 13 feet (2.5 to 4m.) wide. Those along the strike are 
 8 to 13 feet apart, and those along the dip 10 to 16 feet apart, 
 leaving rectangular pillars between them. If the dip exceeds 
 45, tunnels as before are driven along the strike, and these are 
 intersected by horizontal cross tunnels running from the roof to 
 the floor of the deposit. The height and width of these tunnels 
 do not as a rule exceed 10 feet (3m.). If the bed is thick the 
 tunnels are traced out in superposed planes, leaving a solid slice 
 of ground 8 to 10 feet (2.5 to 3 m.) thick between any two 
 successive networks of drivages. 
 
 The first part of the process is now complete, and it is followed 
 by the thinning of the pillars. Beginning near the boundary of 
 the mine, a tunnel is driven through a pillar, or two tunnels are 
 driven if it is a big one. The sides of the tunnels are cut away 
 gradually, until at last the weight of the superincumbent rock 
 breaks down what remains of the pillar; sometimes shots are 
 put in to effect or hasten the fall. As much sulphur rock as 
 possible is taken out, and the next pillar is treated in the same 
 way, and so on, always proceeding from the boundary towards 
 the shaft. 
 
 This method of working has been the cause of the worst accidents 
 and of the majority of the fires, especially when the stratum is 
 thick, and several sets of tunnels have been driven one above the 
 other. In some parts of the Colle Croce mines, Lercara, there 
 have been as many as ten working horizons one above the other, 
 each horizon, or slice, being 16 feet (5 m.) thick, and the bed itself 
 164 feet (50 m.). Sometimes mines of this kind have *' caved in" 
 of themselves ; in other cases the general breaking up and crushing 
 together has been produced intentionally by bringing down some 
 of the lowest pillars by a few shots. During this crush the heat 
 produced by the friction of great masses of rock falling against 
 one another is sufficient to make the sulphur take fire. The mine 
 is then closed, and the fire eventually dies out for want of oxygen, 
 though there are instances of fires going on burning for more 
 than sixty years. When the fire is supposed to be completely 
 
 * " Sui sistemi di lavorazione impiegati nelle sol fare del gruppo di 
 Colle Croce in Lercara, e sui provvedimenti da adottarsi per migliorarne le 
 condizioni di sicurezza," Eivista del servizio minerario nel sSSS, Florence, 
 1890, pp. 67 to 99. 
 
 X 
 
322 OKE AND STONE-MINING. 
 
 extinguished, work is begun in the broken mass, by driving a 
 series of tunnels, along much the same lines as those made 
 originally in the virgin bed. The tunnels are supported by walling 
 and timber. A similar network is then made at a level 18 feet 
 (5.50111.) above, and in some instances there are three such sets of 
 levels in " the broken " one above the other. The tunnels of 
 the lowest horizon are widened out, and by means of suitable shots 
 the whole mass of broken rock is made to fall again, and of course 
 the tunnels disappear. This process of making a network of levels 
 at two or three hoiizons is repeated, and the "ca,ving-in" is 
 brought about again until the sulphur-bearing rock is exhausted, 
 or so much barren stuff from the roof is mixed with it as to 
 make the work unprofitable. 
 
 The crushes themselves have not generally been accompanied by 
 accidents, but work in the broken ground has been very fatal. 
 
 For working these deposits, and especially the thick ones, a 
 filling-up method is preferable, and the " ginesi," or residues from 
 the treatment of the sulphur-rock in kilns, are ready at hand as 
 the most convenient material for the purpose. 
 
 The filling-lip method enables the sulphur bed to be worked 
 away completely, whereas with the method of networks of drivages 
 followed by falls, fully one-fifth or even one-fourth of the mineral 
 is lost. Besides, there are fires and subsidences of the ground 
 causing fissures which let water in, and therefore producing more 
 danger to the men and also to the adjoining mines. 
 
 The Italian Inspectors of Mines are of opinion that poor 
 beds, which could not be wrought profitably by the filling-up pro- 
 cess, may in certain exceptional cases be worked by the old method , 
 because the firmness of the rock increases as the percentage of 
 sulphur diminishes. However, they limit the number of super- 
 posed working floors to three, and stipulate that an upper floor 
 shall be entirely worked out before a lower one is taken, away. 
 
 It is estimated that in the year 1889* only 43 per cent, of the 
 sulphur produced in Sicily came from virgin ground, and that all 
 the rest was obtained from drivings among broken pillars and 
 workings that had " caved in." 
 
 B. Longwall. Having discussed the various ways of work- 
 ing a bed by permanent or temporary pillars, we now come to 
 the so-called longwall method. In this case there is ro pre- 
 liminary carving out into pillars, but the mineral is worked away 
 in long faces, whence the name applied to the system. 
 
 A typical case is found in the workings for copper shale in 
 the Mansfeld district, Germany.f 
 
 * fiivista del servizio miner ar io nel i8Sg, p. 76. 
 
 f This account of the workings of the copper shale is based upon the 
 description in the pamphlet, " Der Kupferschieferbergbau und der Hiitten- 
 betrieb znr Verarbeitung der gewonnenen Minern in den beiden Mansf elder 
 Kreisen der Preuss. Provinz Sachsen,i889," and upon personal observations. 
 
EXPLOITATION. 323 
 
 The bed, as already mentioned, is usually from 3 to 5 inches 
 thick, but it makes up for its thinness and poverty by its 
 uniformity of yield, at all events compared with a mineral vein. 
 
 It is worked for a distance of n miles (18 kil.) along the strike, 
 and the present plan of operations consists in having a set of 
 shafts for every 2^ miles (4 kil.), that is to say a set of shafts 
 serves for the workings ij mile (2 kil.) on each side of it. The 
 great difficulties encountered in sinking shafts through the watery 
 measures above the copper shale have led to the adoption of the 
 system of driving out long crosscuts to intersect the bed on the 
 floor side. These crosscuts can be driven with speed by 
 machine-drills, and various mechanical means are available for 
 haulage. On the other hand, in spite of the considerable im- 
 provements which have been introduced into shaft sinking by the 
 Ivind-Chaudron process, much time is required and a very heavy 
 expenditure of capital. There is also the consideration that if 
 the shafts were on the roof side, crosscuts would have to be 
 driven at the level of the adit in order to get rid of the water. 
 These crosscuts would sometimes traverse the troublesome 
 gypseous measures, full of unknown pools, and they would be 
 above the worked-out bed of copper shale and therefore be subject 
 to slight sinkings of the ground. Crosscuts in the measures 
 below the copper shale do not present these difficulties. Of 
 course it would be possible to lift the water to the surface and not 
 discharge it into the adit. This would entail extra expense for 
 pumping, and in this particular instance there is the further 
 objection that the water is so salt that it cannot be discharged 
 without damage into any small brook. It therefore becomes 
 necessary to conduct it into a river like the Saale, too big to be 
 seriously affected by the briny stream from the mines. 
 
 The workings are arranged in a succession of floors taken 
 exactly 62.7 m. apart. This distance is the equivalent of 30 
 German fathoms, and is 68J yards. To save expense, crosscuts 
 are put out from the shaft at every second floor, that is to say, 
 they are vertically 125.4 metres one below the other. Drivages 
 along the strike are pushed out on each side of the crosscut, 
 and by putting up " rises " each level is brought into com- 
 munication with the one above. Intermediate tunnels are then 
 driven along the shale from a point midway between the two 
 crosscuts, and the bed is now traversed by levels along the 
 strike, at intervals of 62.7 metres vertically, which constitute the 
 main working roadways. As the dip is about 5 or 6, the distance 
 from one main roadway to the next is as much as 600 to 800 
 yards, and constitutes a long working face or "longwall." In 
 Fig. 366, AB represents a main level, and CD the next one 
 below it. E F is the working face, which is cut away gradually 
 till it becomes E' F', and then E" F', and so on. 
 
 This working face is occupied by a string of miners, in fact as 
 
324 
 
 ORE AND STONE MINING. 
 
 many are employed as the space will accommodate. The workman 
 lies upon his left side, reposing upon a shoulder-board and a leg- 
 board. The latter is strapped to the thigh, but the former is free, 
 and is shifted as required. The work comprises the following suc- 
 cessive operations (i) Holing with the pick ; (2) wedging down 
 the copper shale ; (3) blasting down the roof ; (4) stowing the 
 deads. The holing is done in the lowest part of the bed of 
 copper ore, along the hard and smooth floor. Enough of the roof 
 is taken down to give the miner just room enough to do his work. 
 It is best to have as much as 23 inches (58 cm.), but if there is a 
 convenient smooth plane of bedding for forming the roof at a 
 height of i8|- inches (47 cm.) no more is taken down ; indeed, in 
 some exceptional cases the height is only 15! inches (40 cm.). 
 
 FIG. 366. 
 PLAN 
 
 ~ ~ ' ~ ~~ 1 -| -'"' ~ I r^ -"-----. --xv<^^z . ,.-":' .,~^* f/z 
 
 
 ^^^M! !l^^:^ v .gj:Tff:^^^I 
 
 \F* 
 
 The barren rock serves as material for stowing or filling up, and 
 as the quantity is more than sufficient for this purpose, some of it 
 has to be drawn up to the surface. 
 
 It is necessary to have roads for taking away the ore from 
 the face, and they are formed by reserving passages in the 
 stowing and by blasting down the roof, so as to give suffi- 
 cient height. These divisional roads are shown by the letters 
 a b, c d. e /, &c. The interval between them varies from 50 
 to 1 20 yards; and in all cases there are diagonal branch roads 
 leading from the railroad towards the face, which is finally 
 reached by the so-called " Fahrten." They are low passages in 
 the stowing, along which the ore is dragged by boys in little carts. 
 The diagonal roads, however, are made 5 feet high by blasting 
 down the roof. Owing to the small scale of the diagram it is 
 impossible to show all the branch roads connecting the working 
 face with the levels running along the strike. The direction 
 given to the working face is a matter of importance, for it 
 
EXPLOITATION. 325 
 
 enables the amount of pressure coming upon the rock to be varied. 
 The pressure is felt most when the face is parallel to the strike 
 and the working carried up to the rise ; it is felt least when the 
 face is parallel to the strike and the work is proceeding down- 
 wards. If the face runs in a direction parallel to the line of dip, 
 the pressure is intermediate in amount. Therefore by regulating 
 the line of the face, the mining authorities have it in their power 
 to cause what amount of pressure they think most desirable for 
 the work. As a rule the line chosen for the working face lies 
 somewhere between the line of strike and the line of greatest 
 clip. 
 
 in new ground in the deeper workings, holing with the pick 
 is a very laborious operation, and has on that account been given 
 up ; in such places the shale is got by blasting. After the lapse 
 of three-quarters of a year or a year and a half, when a large area 
 has been worked away and the roof begins to subside upon the 
 stowing, pressure is felt on the working face and the holing be- 
 comes much easier. In order to bring about this state of affairs 
 as soon as possible, Jager drills worked by compressed air have 
 been employed in getting the ore. 
 
 The Mansfeld longwall has the peculiarity that more deads 
 are produced than can be stowed away in the excavations ; the. c e 
 are therefore packed very full and the amount of subsidence is 
 not great. 
 
 In some other varieties of the longwall method there is no 
 stowing at all and the roof is allowed to fall in, or the amount 
 of rubbish produced by the seam is insufficient to fill up the empty 
 spaces. There is also a diversity of practice with regard to the 
 direction in which the longwall face is carried, sometimes the 
 seam is worked by longwall outwards that is to say, the face 
 is carried from the neighbourhood of the shaft towards the 
 boundary of the property, in others it is carried " homewards " 
 from the boundary towards the shaft. 
 
 2. VEINS. In the case of a vein, an exploratory pit is 
 often sunk upon it for 20 or 30 fathoms, and, if the indica- 
 tions found in driving out levels warrant further prosecu- 
 tion of the mine, a first working shaft is put down to 
 intersect the lode at a depth of 100 fathoms or more from the 
 surface. Crosscuts are then driven out at intervals of 10, 15, 
 or 20 fathoms to reach the lode as shown in Fig. 367, which 
 represents a section at right angles to the line of strike. 
 Sometimes the main shafts are carried down all the way along 
 the dip of the vein, though perpendicular shafts have the 
 advantage of being better suited for quick winding and 
 cheap pumping, to say nothing of the rapid ascent and descent 
 of the miners in cages. If an inclined shaft appears to be 
 advisable, great care should be taken to sink it in a straight 
 line. The worst shafts are the crooked ones so common in 
 
326 
 
 ORE AND STONE-MINING. 
 
 Cornwall, vertical perhaps for the first hundred fathoms until the 
 lode is struck, and then carried downwards along its varying 
 dip. 
 
 Whatever kind of shaft is adopted, levels are driven out along 
 the strike of the lode, as shown in the longitudinal section (Fig. 368), 
 in the hope of meeting with valuable ore-bodies such as are 
 represented by the stippled portions of the figure. For the 
 purpose of affording ventilation, and still further exploring the 
 ground and working it, intermediate shafts, called winzes 
 (Cornwall), or sumps (North Wales), are sunk in the lode from 
 one level to the other. In some cases the communicating passage 
 is excavated upwards, or, in other words, the miner " puts up a 
 
 SOUTH. 
 
 FIG. 357. 
 
 flirt 
 
 FIG. 368. 
 
 \\ EAST 
 
 rise." When the communication is complete, there is no difler- 
 ence whatever between a rise and a winze. 
 
 On looking at the longitudinal section (Fig. 368), which may be 
 regarded as representing a common state of things, it will at once 
 be remarked that only certain parts of the vein are valuable. 
 When dealing with a bed or seam, we constantly find that the 
 Avhole area covered by it can be worked away profitably. With 
 a lode this is the exception, and therefore the problem of exploit- 
 ation is not the same in the two cases. The vein-miner has to 
 remove portions of a sheet-like deposit usually dipping at a high 
 angle, and the bed-miner to excavate the whole of a sheet-like 
 deposit lying frequently nearly horizontal. The unworked por- 
 tions of the lode serve to support the hanging wall, and form in 
 this way the equivalent of irregular pillars. 
 
 The actual mode of removing the valuable part of the lode 
 itself depends a great deal upon circumstances viz., its width, 
 the nature of its contents, and that of the walls or enclosing 
 rock ; but the methods of working may generally be brought 
 
EXPLOITATION. 
 
 3 2 7 
 
 under one of two heads viz., underhand stoping or overhand 
 sloping. The word " stope" is equivalent to step, and the term 
 " stoping " means working away any deposit in a series of steps. 
 Underhand or bottom stopes are workings arranged like the 
 steps of a staircase seen from above, whilst overhand or back 
 stopes are like similar steps seen from underneath. Both 
 methods have their advantages and disadvantages, and both are 
 largely used. 
 
 We will first take undeiMnd stoping, as this is the older 
 
 FIG. 370. 
 FIG ' 369> 
 
 FIG. 371. 
 
 method. In the old days the miner began in the fioor of the level 
 (Fig. 369), and sank down a few feet, removing the part i ; he 
 followed with 2, 3, 4, &c., until the excavation finally presented 
 the appearance shown in Fig. 370. Any valueless rock or mineral 
 was deposited upon platforms of timber (stulls), and the ore was 
 drawn up into the level by a windlass. One great disadvantage 
 of this method was the cost of winding up the ore and water by 
 hand labour. At the present day the disadvantage would not be 
 so great, because power is so 
 easily conveyed to underground 
 winches by compressed air or elec- 
 tricity. There always remains, 
 however, the necessity of pro- 
 viding much timber for the stulls, 
 if there is a large quantity of 
 worthless stuff in the vein, or if 
 the sides are weak. The advan- 
 tages are that ore can be worked 
 away as soon as a level is driven, 
 that the men are always boring downwards, and, lastly, that tfye 
 ore can be carefully picked after it is broken, without fear of any 
 valuable particles being lost. 
 
 A more economical method of working by underhand stopes, 
 and one largely employed in Cornwall at the present day, consists 
 in reserving any attack upon the ore-ground until a lower level 
 has been driven. A connection is then made between the two 
 levels by sinking a winze from the upper one, or by putting up 
 a rise from the lower one. 
 
 The work of stoping is commenced from the two upper ends of 
 
323 
 
 ORE AND STONE-MINING. 
 
 FIG. 372. 
 
 &R&AT CROS 
 
EXPLOITATION. 
 
 329 
 
 this intermediate shaft, and the lode is removed in a succession 
 of steps, the workings assuming the appearance exhibited in Fig. 
 
 FIG. 373. 
 
 \ 
 
 37i. The steps are gener- 
 ally made steep, so that 
 the ore may readily roll 
 down into the winze, and 
 so that the boreholes may 
 do better execution: but 
 these steep stopes are 
 dangerous if a man hnp- 
 pens to slip and fall. The 
 huge open chasms left by 
 the removal of a wide lode 
 in this way are also a 
 source of danger, for 
 there is always a risk of 
 falls of rock, and from 
 places which cannot easily 
 be examined. 
 
 Figs. 372 and 373 ex- 
 plain the general arrange- 
 ments for working Dol- 
 coath, the largest tin mine 
 in Cornwall. The lode, 
 after producing copper 
 ores for a considerable 
 depth, changed its char- 
 acter and became rich in 
 tin. The workings for tin 
 are confined almost en- 
 tirely to the granite. The 
 section (Fig. 373) shows 
 that the main shaft of the 
 mine is at first vertical and then carried down on the dip of the 
 
 lode. The mine is now consider- 
 ably deeper than indicated in the 
 figures, but the method of work- 
 ing remains the same. 
 
 The process of -overhand 
 stoping is precisely the reverse 
 of that which has been des- 
 cribed : the work is commenced 
 from a rise (Fig. 374, A), or 
 better, from the two ends of a 
 winze (Fig. 374, B). As soon 
 as the men have excavated a 
 sufficient height of the level, they put in strong .pieces of timber 
 from wall to wall (stempds> stull-pieces), and cover these cross- 
 
 FIG. 374. 
 ' 
 
330 
 
 ORE AND STONE-MINING. 
 
 pieces with boards or poles, and throw down the rubbish upon 
 the platform (stull, bunning) thus formed. In the midst of the 
 rubbish, chimney-like openings (mills, passes) are reserved, lined 
 with boards or dry walling, and closed at the bottom with shoots 
 provided with doors. The ore is thrown into these passes, which 
 
 FIG. 375. 
 
 FIG. 376. 
 
 \\X\\\\ \\V\\\\\\\\\ \ 
 
 FIG. 377- 
 
 are tapped when necessary. The ore falls into the tram-waggon 
 placed ready to receive it. 
 
 Fi - 375 is a transverse section, showing the rubbish resting 
 on the stulls. This may be called the typical mode of stoping, 
 when the lode affords enough rubbish for the men to stand on, 
 and to keep them close to the rock they are attacking. Very 
 often such is not the case, and the whole of the lode has to be sent 
 
 up to the surface for treatment. If 
 the walls are firm, a stull is put in, 
 and a sufficient heap of broken ore is 
 left upon it to give the men good 
 standing ground ; the excess is thrown 
 over the ends of the stull, or the great 
 heap is tapped by cutting a hole in 
 the supporting platform and letting 
 a quantity of ore run down into the 
 level. 
 
 Another method consists in putting 
 in temporary stages or platforms 
 upon which the men stand to do their 
 work, whilst the excavation is left as 
 an open space (Fig. 376). This mode 
 of working is incompatible with weak 
 
 walls. If a lode does not afford rubbish enough for completely 
 filling up the excavated space, or if it is too narrow for the men 
 to do their work comfortably, one of the walls may be cut into and 
 blasted down (Fig. 377), in order to give the men a firm bed of 
 rubbish to stand on while at work, and to prevent any chance of a 
 collapse of the mine. In certain special cases rubbish is sent down 
 from the surface to fill up the excavations. 
 
EXPLOITATION. 
 
 FIG. 378. 
 
 The advantages of overhand stoping are that the miner is 
 assisted by gravity in his work, that no ore or rock has to be 
 drawn up by hand labour, and that less timber is required. On 
 the other hand, the miner is always menaced by falls of the roof 
 of his working place ; but as he is close by, he can constantly test 
 the solidity of the roof and sides by sounding them with his 
 sledge. If the rock rings clearly he feels safe, but if it emits 
 a dull hollow sound he knows that it must be taken down at 
 once, or be supported in some way. A last disadvantage of 
 overhand compared with underhand stopes, is the chance of 
 valuable particles of ore being lost in the rubbish ; but this loss 
 can be prevented by laying down planks or sheets of iron while 
 the lode is being broken down. 
 
 When very wide lodes have to be worked, recourse is often 
 had to a filling-up method, and, indeed, such a method becomes 
 imperative if the sides are weak. The great lode at the famous 
 Van Mine, in Montgomeryshire, once the premier lead mine 
 of the United Kingdom, had 
 to be worked in this fashion, 
 and as the work was carried 
 out very carefully and sys- 
 tematically, no better example 
 of the method can be chosen. 
 The lode is evidently a fis- 
 sure vein as it cuts across the 
 planes of bedding and of 
 cleavage of the adjacent slate 
 rock. It is composed of three 
 parts : the flucan or soft lode 
 B (Fig. 378), the bastard lode 
 C, and the regular lode E. 
 The flucan consists of clay 
 and soft broken slate. The 
 bastard lode is a mass of slate rock, 4 or 5 fathoms wide, between 
 the flucan and the regular lode ; it is much softer than the true 
 country, and, though intersected by numerous small strings of 
 galena, is rarely rich enough to be worked. The regular lode consists 
 of masses of slate traversed by veins of galena, or it is a breccia of 
 fragments of slate cemented together by quartz, galena and blende. 
 The regular lode was at times as much as 48 feet (14.60 m.) wide, 
 and if the excavation formed by the removal of such a quantity of 
 rock had been left open, the hanging wall would speedily have 
 fallen in, and indeed even during the progress of the work the 
 men would have been exposed to very great danger. A filling-up 
 method was therefore adopted, and as soon as the ore had been 
 removed the open spaces were packed with rubbish. 
 
 Crosscuts were driven out at vertical intervals of about 15 fathoms 
 to reach tliojlucan B, which was chosen for driving a preliminary 
 
332 ORE AND STONE-MINING. 
 
 east and west level on account of its softness. This preliminary 
 level enabled the regular lode to be reached very quickly in several 
 places by short crosscuts, from which the first level in the lode 
 was pushed out east and west. 
 
 The next process consisted in stripping away, both sides of the 
 level, as far as the footwall on the north and the bastard lode 
 on the south, unless the latter happened to be productive, in 
 which case it likewise was excavated. This left a space about 
 7 feet high, which was at once filled with deads, save a 
 working level reserved in the middle, which was properly secured 
 with timber. Endeavours were always made to keep this level as 
 straight as possible, so as to facilitate the tramming. The letter 
 H in Fig. 378 represents this working level. Upon its com- 
 pletion the preliminary level became superfluous ; the timber 
 was drawn out and allowed to crush together, as shown in the 
 lower part of the figure. 
 
 In the meantime, starting from the level above, winzes were 
 sunk, 20 or 30 fathoms apart, in the flucan or in the lode 
 itself, if the flucan happened to be too far away from the produc- 
 tive part. The winzes served not only for ventilation, but also 
 as shoots for the rubbish used in filling up ; they were called 
 passes, I (Fig. 378). They were carefully timbered and divided 
 into two compartments : one was used as a passage for the rub- 
 bish, the other was provided with ladders, and formed a foot- 
 way, besides affording access to the other compartment, in case 
 it became choked with the waste rock shot down it. 
 
 As soon as arrangements for supplying the deads were complete, 
 stoping was begun. The height taken off in each stope varied, 
 according to the firmness of the lode, from 2 to 6 feet, and when 
 the ore was removed the excavation was packed with rubbish 
 (D) drawn down from the nearest pass, such as I (Fig. 378), 
 and wheeled in a barrow to the place where it was wanted. As 
 the passes were made at close intervals, the amount of wheeling 
 was very little. The broken ore was thrown down into a pass or 
 mill, K, whence it could be drawn off at pleasure into a waggon. 
 The ore-passes were of the same size as the winzes sunk for 
 letting down the rubbish, and were timbered and divided into 
 two compartments in the same way. 
 
 The lode itself furnished enough rubbish to fill up about one- 
 third of the excavation ; waste rock was likewise obtainable from 
 workings in dead ground, such as crosscuts, and the preliminary 
 or permanent levels ; and finally slate was quarried at the surface, 
 shot down special shafts, and trammed through a level such as P, 
 and a crosscut N and level H, to any special pass where it was 
 required. To prevent any loss of ore among the loose stones used 
 for filling up (stowing), it was usual to spread over the top of the 
 rubbish a layer of soft flucan for a depth of a few inches, and when 
 the lode had been stoped away to the required height, this floor 
 
EXPLOITATION. 333 
 
 was shovelled into the ore-passes and went to the dressing floor 
 with the rest of the stuff. It was found cheaper and better to 
 dress a few extra tons of stuff than to pay for laying down boards 
 or sheets of iron to catch the fine ore. 
 
 Slice after slice was taken off in this way, and the long working 
 face formed by the roof of the stopes corresponded in some measure 
 to a longwall face in bed mining. On arriving within 1 2 feet of 
 the old workings above, packed with rubbish, it was unadvisable 
 to make openings of the full width of the lode, and the ore was got 
 by crosscuts. A level was driven along the strike in the middle of 
 the lode, or on one side if more convenient ; crosscuts, from 5 to 8 
 feet wide, were started from each side of it, and driven north and 
 south to the footwall and hanging wall respectively, the ground 
 being supported by strong props of timber. The lode standing on 
 the sides of the crosscut was then removed by a series of cross 
 drivages similar to the original crosscut, only, as one side was free, 
 the work was much less expensive, costing abont ^4 per fathom 
 instead of 10. The empty spaces were packed with waste to 
 the top, and as much of the timber was drawn away as could be 
 removed with safety. 
 
 When the lower half of the i2-feet slice had been taken away 
 in this fashion by a series of short contiguous cross drivages, 
 another level was driven along the strike above the old one which 
 had been filled with rubbish. Crosscuts similar to the ones below 
 were driven, save that spilling had to be resorted to, as the roof 
 was formed of the deads of the earlier workings. Whilst this 
 work was going on, the miners could recover any pieces of timber 
 which had been left in the midst of the rubbish used for stowing 
 the lower half of the slice. The legs or forks were always put in 
 with the large end uppermost, and could be drawn up by putting a 
 chain round the top and applying a lever. As soon as the upper 
 half of the i2-feet slice had been taken off by these cross drivages, 
 the working level H above it was filled up and abandoned. 
 
 The block of lode 1 5 fathoms high was thus removed entirely, 
 and its place filled by rubbish ; consequently there was no danger 
 of the walls falling in and of the mine collapsing. No high openings 
 were made during the progress of the work, so the roof and sides 
 could be sounded and examined without scaffolding ; any loose 
 pieces could be taken down at once, and there was little fear of 
 their falling unawares upon the miners. 
 
 Before a block was completely stoped away, the so-called perma- 
 nent level at the bottom had to be prepared, in order to furnish a 
 road for conveying deads to the block beneath. Crosscuts, N, 
 were pushed out from the level H, at intervals of 20 or 30 
 fathoms, to a distance of 10 fathoms beyond the fiucan, and " ends " 
 were driven east and west till they met and formed a continuous 
 gallery, P. Piails were laid and the road was reafy for use. 
 
 Several men were kept constantly employed at a quarry 
 
334 
 
 ORE AND STONE-MINING. 
 
 adjoining the mine for obtaining slate, which was trnmmed to 
 and shot down one of the two special rubbish shafts. These could 
 be tapped at the adit, and the supplies were conveyed by tram- 
 roads and other special shafts, used as shoots, to the places where 
 they were required. Excepting the first two rubbish shafts from 
 the surface, no shoots were made more than 15 fathoms deep, 
 because it was found by experience that the timber was broken up 
 very quickly by the fall of the stuff when they were deeper. The 
 bottom of one shoot was always near the mouth of the next, so 
 that the rubbish never had to be trammed far; and in some 
 instances the shoots were so near that, by fixing a few planks 
 in a sloping direction, the waste rock ran directly from one to 
 the other. 
 
 I have entered somewhat into detail in this case, because wide 
 lodes with weak walls have often given much trouble, when the 
 attempt has been made to work them with the use of timber 
 
 FIG. 379. 
 
 FIG. 380. 
 
 supports. The amount of timber required at the Van Mine was 
 small, and many of the pieces were used over and over again. 
 Another advantage in this particular case was the certainty that 
 no ore was lost or left behind ; for although money was sometimes 
 spent in breaking down poor parts of the lode to make sure of not 
 missing any lead ore, the barren rock could be utilised for filling, 
 instead of drawing supplies from quarries at the surface. 
 
 At the Van Mine the lode was firm enough to allow the whole 
 width to stand without supports during the time a stope was carried 
 along, except in the case of the two last slices at the top of a block. 
 These, as we have seen, were taken off by a succession of conti- 
 guous crosscuts. When a lode is wide and too weak to stand open 
 with safety for its whole width, the crosscut method may be 
 applied from the beginning, instead of confining it to the last 
 slices. 
 
 The method is illustrated by Figs. 379 and 380. The lode is 
 removed in successive horizontal slices, A B C D E, beginning 
 at the bottom, and for each slice a level, L, is driven, either wholly 
 in the lode, or partly or entirely in the country ; from this level, 
 
EXPLOITATION. 
 
 335 
 
 FIG. 
 
 crosscuts are put out 6 or 8 feet wide, as shown in the plan 
 (Fig. 380). These are regularly timbered, according to the necessi- 
 ties of the case, and when No. i is completed, No. 2 is begun, and 
 the rubbish from No. 2 thrown into the empty space of No. i cross- 
 cut. If the quantity is insufficient, deads are brought in from the 
 surface or from exploratory workings in worthless rock in the 
 neighbourhood. Sometimes the crosscuts are not driven side by 
 side, but i and 5 may be driven first, leaving 2, 3, and 4 as a solid 
 pillar ; then 3 is worked away, and finally 2 and 4 between the 
 timber and rubbish on each side. The greater part of the timber 
 can be recovered when the next slice above is taken off, as the 
 props are put in with their small ends downwards, and can be 
 drawn up with a lever. M (Fig. 379) is a level reserved in the 
 deads for traffic and ventilation. This method of working is 
 applicable not only to lodes, but also to irregular masses. 
 
 The mode of working the soft ore-bodies such as are met with 
 in the Com stock lode, in the Eureka- Richmond mines, Nevada, 
 and at Broken Hill in New South Wales, 
 has been already described in the chapter 
 upon timbering. The excavations are 
 supported by huge frames of timber, made 
 by adding one " square set " to another as 
 required, and are finally filled up entirely 
 with rubbish. 
 
 Another method of working a wide lode 
 is to attack it in slices parallel to the dip, 
 removing each slice separately, as if it were 
 a lode of ordinary dimensions, and filling 
 up with rubbish (Fig. 381). 
 
 We have here been supposing that the 
 
 whole of the lode is taken away from wall to wall. Other cases 
 may arise. Thus at Foxdale mine, in the Isle of Man, we have to 
 deal with a vein of lead-bearing rock which is not ore-bearing for 
 its entire width. The vein runs east and west, and in places is 
 140 feet wide. Levels are driven along the northern and southern 
 boundaries, and show whether or no there is any payable ground 
 on these walls ; crosscuts put through from time to time further 
 prove the lode, and sometimes there may be three parallel workable 
 portions with barren rock between them. Each of these portions, 
 which will rarely exceed 1 2 feet in width, is then treated as a 
 separate lode. 
 
 The rule at Foxdale (Fig. 382) is to drive the levels 15 fathoms 
 apart, and to effect a communication between two adjacent levels 
 at intervals of 30 fathoms, either by a rise or a winze. The lode 
 thus becomes cut up into blocks 15 fathoms deep by 30 fathoms 
 long, in the direction of the strike. These blocks are worked 
 away from below upwards in separate "pitches," each 10 fathoms 
 long, arranged like three steps. The block therefore affords 
 
336 
 
 OKE AND STONE-MINING. 
 
 three pitches, or subordinate blocks. Thus if ABDO represents 
 a block contained between an upper level AB and a level CD, 
 15 fathoms below it, and bounded on the two ends by the 
 winzes AC and BD, we must first divide it in imagination into 
 the three parts AEGC, EFHG, and FBDH. The removal of 
 each pitch, or third of a block, is confided to a separate set of 
 men. The first set begin at the bottom of AEGC, and take off 
 a slice 6 feet thick, filling up the vacant space with rubbish ; 
 then they begin a second slice, and go on taking off slice after 
 slice until they reach the level above. 
 
 Work upon the second division viz., EFGH, is not begun 
 until the first slice of the adjacent " pitch " has been filled up, 
 
 FIG. 382. 
 
 . SCALE 
 
 2 4- 6 8 10 12 14. 16 18 20 22 FATHOMS 
 
 05 IO 15 20 25 30 35 4-0 45 METRES 
 
 and in the same way block FBDH is not attacked until at 
 least one slice of EFHG has been worked away. At some given 
 time the workings will have assumed the form, shown in the 
 figure. 
 
 If, as is often the case, there is a hard and a soft part in the 
 lode, the work in the overhand stopes goes on as follows : Start- 
 ing from a winze, the miners push on a drivage in the soft part, 
 and timber it up with a cap resting upon the hard side and 
 upon one leg (Fig. 383). This renders the working of the hard 
 part very much less expensive, for it can be got by shots which 
 take full effect in such large openings. Before blasting out the 
 side, the caps are supported by a longitudinal carrier resting 
 upon a few upright props in the manner shown in figure 384. 
 
 All the rock is picked in the mine, and any waste is used for 
 filling up. At last the whole excavation that has been made 
 is packed, with the exception of a passage, 18 inches high, below 
 the caps, along which the men can creep if necessary. A floor 
 of planks is laid down, and serves to make a bed to prevent the 
 
FIG. 383. 
 
 Scale c* Melrre>s 
 
 f. * 
 
 Fl . 3 4. 
 
 4 Y 
 
 / >-- ; 
 
 (& 
 
 
 A. Granite, or barren part of the lode ; B. Soft part of the lode ; 
 C. Hard part of the lode ; D. Leg ; E. Cap ; F. Floor of planks ; 
 G. Longitudinal cap or carrier ; H. Prop ; I. Prop ; K. Filling 
 of waste rock. 
 
 Y 
 
33 8 ORE AND STONE-MINING. 
 
 loss of small ore when the next stope or slice is taken off. Shoots 
 or " passes" lined with timber are reserved in the rubbish ; there 
 is generally one at the end of each pitch and one in the middle. 
 In this way the miner always has one close at hand, and never 
 need wheel the ore very far. The shoots are furnished with doors 
 at the bottom, and the ore is drawn off directly into waggons 
 underneath without any shovelling. 
 
 Care is taken to drive a crosscut from time to time, to prevent 
 any chance of possible bunches of ore in the sides being missed. 
 Waste rock obtained in this way is always useful for filling up. 
 The Foxdale lode furnishes about enough barren rock to fill up 
 the excavation, without its being necessary to draw supplies from 
 the surface. 
 
 The timber buried in the rubbish is not lost, for it can be 
 withdrawn when the next slice is taken off. A piece of J-inch 
 iron chain is made fast round the top of the leg, which always 
 has the small end at the bottom, and the hook of a special lever 
 is put into a suitable link. The fulcrum of the lever is carried 
 by an upright bar attached to a square base, and by applying 
 pressure to the lever the leg is gradually pulled up. 
 
 Wide Lodes worked with Pillars and Chambers. The present 
 method of working the wide veins at the Rio Tinto mines may be 
 briefly described as pillar and chamber work, with a solid roof and 
 floor between the working horizons. For the present the pillars 
 must be looked upon as permanent. 
 
 The details of the system are as follows : A vertical shaft is 
 sunk in the adjacent rock, and crosscuts are driven out to the 
 lode at intervals of 25 metres (82 feet) ; these form the main 
 working floors or horizons. A main level is carried along the 
 strike of the lode at each horizon, and, by sinking from one level 
 and rising from the one below, a vertical intermediate shaft is 
 formed, effecting a communication between them. All this 
 preliminary work is done by the aid of rook drills. An inter- 
 mediate level is next pushed out along the strike by hand labour 
 midway between the two main levels ; the vein may then be 
 regarded in imagination as divided into a series of horizontal 
 slices, each 12 J metres in thickness, as shown by the dotted lines, 
 AB, CD, EF, &c. in the section (Fig. 385). The formation of 
 pillars now begins : the lower part of each slice is cut up by a 
 network of drivages 3 to 3^ metres wide, and 3 to 3^ metres high, 
 at right angles to one another, leaving pillars 6J to 7 metres 
 square (Fig. 386). A very large amount of ore is produced 
 in this way. The next stage in the process of mining is 
 heightening and widening the chambers ; in ordinary hard 
 pyrites the pillars can be thinned 'down until they measure only 
 3 metres by 3 metres, and the chambers can be carried to a 
 height of 9 to 10 metres. Where the ground is weak more has 
 to be left for support. The two plans (Figs. 386 and 387) show the 
 
EXPLOITATION. 
 
 339 
 
 initial size and the final size of the pillars, whilst the section 
 (Fig. 385) further explains the progress of the work. At the 225- 
 metres horizon there are preliminary levels 3 metres wide and 
 pillars of 7 metres ; at the 212^-metres horizon the enlargement 
 of the chambers has begun ; at the 2oo-metres level the process 
 has been carried further, and at the two upper horizons it has 
 been completed, the pillars being reduced to 3 metres. The solid 
 slice of ore, 2 J to 3^ metres thick between two storeys, remains for 
 the present untouched, and forms with the small pillars a reserve 
 stock which can be removed at some future time. Great care is 
 taken to arrange the pillars vertically one under the other with 
 
 FJG - 38S ' FIG. 386. 
 
 ' 
 
 FIG. 387. 
 
 D ^ 13 
 D E3 ED 
 
 SCALE. 
 
 UtTfltSIO S 
 
 20 METRES 
 
 their centre lines coinciding exactly. When operations have 
 been finished, the workings have the appearance of very high 
 columns supporting huge arches. It must not be supposed that 
 the honeycombed part of the vein formed by the deserted chambers 
 is entirely unproductive; a very large surface of ore is left 
 exposed to the action of air and moisture, oxidation goes on, 
 copper and iron sulphates are produced, and during the rainy 
 season water trickling down the sides of the caverns carries them 
 in solution to the bottom of the mine. The coppery water 
 pumped up from underground is led into precipitation pits, 
 similar to those employed for treating the cupreous solutions 
 obtained more rapidly from the ore burnt at the surface. 
 
 At the present time the quantity of ore in sight is so great 
 that it is not necessary to devise schemes for removing the 
 reserves; but the work might be accomplished by a filling-up 
 process, beginning at the bottom. The pillars and the intervening 
 
340 
 
 ORE AND STONE-MINING. 
 
 solid floors of ore could be removed as horizontal slices, fol- 
 lowed by a filling up with rubbish let down from the surface. 
 In this manner the workmen would always be standing on firm 
 ground within easy reach of the ore. 
 
 3. MASSES. The methods of working masses may be classified 
 thus: 
 
 (a) Method by chambers without filling up. 
 
 (b) Method by hoiizontal slices, taken in descending order, allowing 
 
 the surface to sink down. 
 
 (e) Method by horizontal slices, taken in ascending order, with 
 complete filling up. 
 
 (a) The first of the three methods is applicable when the enclosing 
 rock is strong enough to allow chambers to be worked out without 
 
 FIG. 388. 
 
 SCALE 
 
 J 2 4- 68 10 YARDS 
 
 A. " Grey limestone"; B. Limestone,the so-called " Crease measures )r ; 
 
 C. Chambers or caverns left by the excavation of the ore ; 
 
 D. Brown haematite; E. Top or Whitehead limestone ; F. Sand- 
 stone (Millstone Grit) ; G Main level ; H. Supporting pillar 
 built up of stones and timber. 
 
 danger from the roof and sides falling in. As an instance I may 
 take the so-called " churns " of the Forest of Dean, which are 
 worked for iron ore. Brown haematite occurs in irregular pockets 
 in a certain bed of the Mountain Limestone (Fig. 388), which is from 
 14 to 1 6 yards thick, and usually dips at a considerable angle. At 
 the particular mine chosen as an example the dip is 52. Perpen- 
 dicular shafts are sunk, and the ore-bearing limestone is reached 
 by crosscuts at vertical intervals of 100 to 150 feet. A good main 
 level is driven along the strike of this bed, and small crosscuts are 
 put out in order to search for the churns, which have often been 
 
EXPLOITATION. 341 
 
 followed down from the surface to a depth of 200 yards. The 
 exploitation consists in removing the soft ore with the pick, and 
 supporting the roof with occasional props or rough walls built with 
 pieces of barren rock ; timber and stone may be used together, as 
 shown in the figure. If the pocket is very steep it is worked like 
 a mineral vein ; the men stope the ore away overhand, standing 
 upon platforms of timber erected across the chasm left by workings 
 below. 
 
 (6) An excellent example of the second method of working is 
 furnished by De Beers diamond mine, where a mass of diamond- 
 
 FIG. 389. 
 
 bearing rock occurs as a huge vertical column, with an irregular 
 oval section (Figs. 30 and 31). It was worked for many years as 
 an open quarry, but falls of the surrounding rocks (reef} caused 
 so much trouble, as the huge pit increased in depth, that under- 
 ground mining had to be adopted. 
 
 The system consists in excavating chambers, and then letting 
 rubbish from the open pit above run in and fill them up. The 
 details of the method will be plain from consulting Figs. 389, 390, 
 and 391, which are copied from the second and third annual 
 reports of the De Beers Company. The deposit is reached by an 
 inclined shaft sunk in the surrounding rocks, and main levels 
 are driven at successive horizons which are from 90 to 120 feet 
 apart vertically. Fig 389 shows these main drivages at the 800- 
 
342 
 
 ORE AND STONE-MINING. 
 
 FIG. 390. 
 
 SCALES 
 
 10 U 30 40 JO 60 70 80 M lOOFttT 
 
 FIG. 391. 
 
 feet level; there are two 
 principal drivages parallel 
 to each other and follow- 
 ing the direction of the 
 axis of the rough oval, and 
 from them cross tunnels 
 are put out at intervals 
 of 36 feet, and extended 
 to the limits of the " blue," 
 or, when directed to- 
 wards each other, till 
 they meet. Another set 
 of levels is driven at a 
 depth of 30 feet below 
 the main tunnels, and a 
 third set at a further 
 depth of 30 feet. The 
 block of ground between 
 two main horizons thus 
 becomes divided up into a 
 series of horizontal slices, 
 30 feet thick, each of 
 which is cut up by a net- 
 work of tunnels 36 feet 
 apart extending to the 
 surrounding rock. 
 
 When this rock is 
 reached, the tunnels are 
 widened out till two adja- 
 cent working-places meet 
 
 as shown in the plan (Fig. 390). The next process is to rise, or work 
 upwards, until the "blue" is traversed and the waste fallen rock 
 
 FIG. 392. 
 
 Orioincd surface 
 
 A. Enclosing limestone ; B. Red hematite ; C. Sand and clay ; 
 D. Glacial drift. 
 
EXPLOITATION. 
 
 343 
 
 above it is met with. This is allowed to run in and form a heap 
 upon which the workmen stand, in order to blast down the re- 
 maining part of the slice of " blue." As this is taken away the 
 waste rock (reef] follows. Fig. 391 also shows that the workings 
 in an upper slice are always further advanced than those in a 
 lower one. Only the main levels are provided with regular 
 tramways. The blue got in the intermediate levels is thrown 
 
 Fie. 
 
 Shaft 
 
 Sand &c: 
 
 Jron Ore. 
 
 JLimestonc, 
 
 down shoots, and so finds its way to the main level, whence it 
 can be hoisted to the surface. 
 
 A somewhat similar mode of working is customary in the iron 
 mines of North Lancashire, which have to deal with irregular 
 masses of haematite in the Mountain Limestone (Fig. 392).* 
 
 Shafts are sunk at a distance from the deposit, which is reached 
 by crosscuts at intervals of 10 fathoms vertically. Levels and 
 cross levels are then driven which bring all parts within easy 
 reach (Fig. 393). Rises, R, R, are put up from the main floor 
 
 * I am indebted to Mr. J. G. Lawn, A.R.S.M. and De la Beche 
 Medallist, for his notes on the method of working ; from these, and from 
 my own recollections, this description has been written. 
 
344 
 
 ORE AND STONE-MINING. 
 
 or horizon to the next one above, and the deposit is now taken 
 away in slices or " heights," 9 or TO feet thick. A and B of 
 Eig. 394 represent two adjacent rises. The men starting from 
 A, push out the drift J, and those from B the drift /, until they 
 meet, for the sake of ventilation. This air-road il has to be 
 kept open while work is proceeding in the slice or height in this 
 district. Branch drifts, 2 and 77, are carried forward to the 
 boundary of the deposit or of the area the men have to work, and 
 lastly comes the robbing of the ore by a series of drifts, such as 
 3, 4* 5 6> or IH* IV, V* in tn e order of the numbers. The 
 
 work is thus carried on towards a rise and not from it. 
 After the ore is robbed, the roof crushes in, smashing the 
 timber and forming a safe ceiling for the workings in the 
 
 FIG. 394. 
 
 Rise 
 
 next slice underneath. The surface sinks down in proportion as 
 the ore is removed, so that in some parts of the district immense 
 holes exist, giving evidence of the working out of vast bodies of 
 haematite underneath (Fig. 392). As the overlying drift often 
 contains clay, rain water collects in these holes, and it has to be 
 pumped out lest it should break through and drown the miners. 
 
 The rises are usually made 6 feet by 4 feet 6 inches within the 
 timbering, which consists of sets of Norway or Swedish timber 
 6 or 7 inches square, simply halved at the joints and placed 
 directly one above the other. Most of the rises are divided into 
 two compartments by pieces of 3-inch plank cut to the right 
 length and wedged in; these are made firm by nailing on to 
 the rise-timber "listing pieces," strips of wood 3 inches by f 
 inch, on each side. One of the compartments serves for a ladder- 
 way, for pulling up timber and for an airway ; the other as a 
 receptacle for the ore. The latter is called a "hurry," and is 
 provided at the bottom with an inclined shoot through which the 
 ore can be let into waggons or " bogies " at pleasure. Sometimes 
 
EXPLOITATION. 
 
 345 
 
 the rise is made 9 feet by 4 feet 6 inches, and divided into three 
 compartments viz., two hurries, and a ladderway between them. 
 One hurry then serves for ore, and the other for rubbish. 
 
 When the men have all but removed one slice or "height," they 
 take out the timber of the rise on one side, in order to start a new 
 drift ; it is about 7 feet wide, and is supported by frames, each 
 made of a cap or head -tree resting upon two legs or " forks." To 
 protect the men while working in the forebreast, small planks 
 (spiles) are driven under one head-tree and over the next, and, 
 if necessary, along the sides behind the props. The men are not 
 allowed to advance more than 4 feet beyond their timber. As 
 soon as the slice above is quite exhausted, they open out at the 
 other side of their rise, and after putting in a strong covering of 
 
 
 timber, they clear all the rise of its lining down to the level at 
 which they are working. In driving below the old timber and 
 rubbish, it is necessary to be careful that the supporting frames 
 are properly put in and kept well forward ; they are often held in 
 place by nailing spiles to them, but this is only necessary before 
 they get the weight from above. It is possible in many cases to 
 save much of the timber used in lining the drifts which are made 
 for robbing the ore, but in all cases the roof comes down very 
 quickly, whether the timber is left in or not. 
 
 (c) The last method namely, working away the mass by hori- 
 zontal slices, in ascending order, with complete filling up 
 exactly resembles that which is adopted for certain wide veins, 
 such as the lode at the Van mine, Montgomeryshire. However, 
 it may be well to mention, as an example, the great zinc ore 
 stockwork at Diepenlinchen, near Stolberg. The Mountain 
 Limestone is full of cracks and cavities containing blende, which 
 cannot be worked to advantage without breaking down the whole 
 
316 
 
 ORE AND STONE-MINING. 
 
 of the rock. The limestone is ore-bearing over an oval area, 
 120 metres long from east to west and 50 from north to south 
 (130 yards by 54 yards). 
 
 This great mass of zinc-bearing rock is subdivided for the pur- 
 pose of working into a series of storeys or floors, each 16 metres 
 (52 J feet) thick vertically, and a main level is driven along the 
 major axis of the oval at the bottom of each storey, as shown in 
 Fig. 396. Cross-cuts, 14 metres apart, are driven out north and 
 south from each main level, and are connected with similar cross- 
 cuts below by winzes. The block of ground between two main 
 levels is then taken away in slices, 2 metres thick, in ascending 
 order. However, with the view of saving the expense of putting 
 
 FIG. 396. 
 
 200 METRES LEVEL 
 
 r ____^_^_^^__ n __ n _____^_^ / METRCS LEVEL 
 
 T 2%#2^^ 
 
 in timber to support the deads, which would be necessary if the 
 main roads had to be kept up in a part of the mine stowed with 
 rubbish, the first two slices that is to say, the one in which the 
 levels are driven and the one immediately above it are left intact 
 at the outset. Work is started from a winze at a point 2 metres 
 above the top of the level, and the whole area of the deposit cleared 
 out for a height of 2 metres ; the excavation is then filled up with 
 deads. The deads are obtained by picking the rock broken down 
 in the stopes, or from any drivings or sinkings in barren ground, 
 and also by sending down supplies from the surface. Shoots are 
 reserved in the stowing for throwing down the ore, which is 
 drawn off at the bottom when required. 
 
 Fig. 396 shows the stoping going on between the 200 and the 
 2i6-metres levels. When the stopes come up to the sole of the 
 2oo-metres level, the ore surrounding the network of levels and 
 that of the overlying slice can be attacked. By this time this 
 double slice, 4 metres thick, is somewhat crushed and broken. 
 
EXPLOITATION. 347 
 
 It would be dangerous to have the wide working-places, which 
 can be excavated without fear in virgin ground; therefore, 
 just as happened in the Van Mine, the two last slices are 
 got by a series of small drivings, in which the miners resort to 
 a process of spilling. By applying this process the remainder 
 of the ore is obtained in safety, and the final result is that the 
 great mass of zinc-bearing rock is replaced by barren material 
 with the expenditure of very little money for timber. 
 
( 348 ) 
 
 CHAPTER VII. 
 HAULAGE OR TRANSPORT. 
 
 Underground transport Shoots Pipes Carriage by persons Sledges 
 Wheeled vehicles Mechanical haulage Boats Transport above 
 ground by similar means and by aerial ropeways. 
 
 AFTER having been excavated, the mineral must be conveyed 
 to the surface. In very many cases the journey is performed in 
 two stages first, along a more or less horizontal road to the shaft- 
 bottom ; and thence by a vertical or inclined road which leads up 
 to the daylight. The first process is often spoken of as haulage 
 and the second as winding : but there is no distinct line of de- 
 marcation between the two, for certain sloping passages, called 
 shafts by the ore-miner, would be denied that name by the collier. 
 It will be convenient to say a few words here about transport 
 above ground, although, strictly speaking, this subject should not 
 be dealt with until after the chapter on winding. 
 
 The transit of the mineral from the working-place to the 
 shaft may be carried on in part or wholly by one of the following 
 processes : 
 
 I. Fall down a shoot (mill or pass]. 
 II. Flow along pipes or troughs (launders). 
 
 III. Carriage by persons. 
 
 IV. Conveyance by sledges. 
 
 V. vehicles with wheels. 
 
 VI. boats. 
 
 I. FALL DOWN A SHOOT. This first method is one to 
 which reference has already been made more than once in 
 describing the modes of working. When a deposit is inclined at 
 a steep angle, or when a mass has to be dealt with, the mineral 
 will readily drop from the working-place to the level below. The 
 passages provided for this purpose are called " shoots," " passes," 
 or " mills/' 
 
 If the excavation is filled up with rubbish, a space like a small 
 shaft is reserved in the stowing by building a wall with some 
 of the large stones. This kind of " pass " may be described as 
 a large chimney, about 3 feet in diameter, lined with coarse 
 rubble masonry. To prevent choking, it is advisable to make 
 the pass slightly conical, the large end at the bottom. It may 
 
HAULAGE OR TRANSPORT. 349 
 
 be constructed in the middle of the rubbish, or if there is a 
 convenient smooth face on the footwall of a lode, a semicircular 
 wall built against it encloses a space very suitable for the purpose 
 required. The pass may serve also as a climbing way for the 
 men, especially if it is provided with a chain ; but it should be 
 used in this manner only for short distances. It is far better to 
 keep the ore-pass distinct from the climbing way, in case any 
 stones should lodge on the sides and fall during the ascent or 
 descent of the men. 
 
 A pass is often lined with timber instead of stone, and some- 
 times it is merely an intermediate shaft or winze set apart as a 
 shoot. At the Van Mine the passes, whether they are small 
 shafts sunk on purpose, or passages reserved in the rubbish 
 used as filling, are 6 feet by 3 feet, within the timber ; 
 each pass is divided into two unequal compartments by a 
 partition made of ij-inch plank nailed to cross-timbers 
 called dividings, and the larger one is closely lined with similar 
 planks. This forms the " shoot " proper. The small compart- 
 ment is provided with ladders and serves as a climbing way, and 
 is also useful in case the larger one should become choked ; 
 a board can be taken out from the side at any time, and large 
 stones obstructing the passage can be dislodged with safety. 
 Vertical passes lined with timber sometimes have pieces of steel 
 rail put across at intervals, to break the fall of the " stuff." 
 
 The pass is provided at the bottom with a mouth closed by a 
 door of some kind, and when this is opened, the mineral falls out 
 into the waggon which has been brought underneath. 
 
 II. FLOW ALONG PIPES. This method of transport 
 becomes available when one has to deal with liquid or gaseous 
 minerals, or with solutions, but these cases occur more frequently 
 above than below ground. However, brine is led along wooden 
 launders and pipes in some salt mines. Natural inflammable gas 
 in a few exceptional cases is piped off from a blower and buint 
 for illuminating purposes j this is done at a salt mine at Bex in 
 Switzerland. 
 
 III. CARRIAGE BY PERSONS. The simplest and no 
 doubt the oldest method of transport along underground roads is 
 carriage by persons. It still survives in some places for short 
 distances. 
 
 In the Forest of Dean, boys carry iron ore on the back in oval 
 trays, called " billies," from the actual working-place to the 
 nearest barrow-road or waggon-road. The tray is made of wood, 
 with a rim of sheet iron, and is about 6 inches deep, 22 inches 
 in length in the direction of the long axis, and 12 to 15 in the 
 direction of the short one. The load carried in a " billy " varies, 
 according to the nature of the ore and the strength of the lad, 
 from 90 to 1 12 Ibs. or even more. The lad goes on all-fours, 
 using his hands to support himself as he makes his way through 
 
350 OHE AND STONE-MINING. 
 
 low and tortuous passages. This method of transport is rendered 
 necessary by the nature of the excavations, which are very irreg- 
 ular; but the distances along which the ore is carried are small, 
 generally from 30 or 40 to 50 yards, and rarely as much as 
 100 yards. 
 
 The German miner commonly makes use of a tray into which 
 he scrapes his mineral or rubbish with a tool like a hoe, and he 
 then carries his load to the nearest " pass " or to a waggon-road 
 in the immediate neighbourhood. 
 
 In the little slate mines near Cochem on the Moselle, men and 
 lads carry up the blocks of slate upon their backs, walking upon 
 steps cut in the rock. They come up with their hands ,upon 
 the ground, bent almost double under the weight of the block, 
 which rests upon a thick pad. Again, blocks of slate are still 
 carried on the back from the working-place to the waggon-roads 
 in the slate mines of the Ardennes. In the Sicilian sulphur 
 mines the same method is common, and it is also found in 
 some parts of Spain and China, where baskets are used, whilst 
 bags are employed in Mexico and Japan. Indeed, in these cases, 
 as at Cochem, the mineral is not only carried along comparatively 
 level roads but is also brought to the surface. 
 
 IV. CONVEYANCE BY SLEDGES. Sledges, or sleds, 
 enable greater loads to be transported ; but they are not available 
 unless the conveyance takes place along roads sloping downwards. 
 They are little employed underground. 
 
 V. CONVEYANCE BY VEHICLES WITH WHEELS. 
 We now come to the methods by which minerals and rubbish are 
 usually transported both above and below ground viz,, by some 
 kind of wheeled vehicle. Here we may at once make two classes. 
 A. Vehicles running upon the ground or on boards ; B. vehicles 
 running upon rails. 
 
 A. Vehicles Running on the Ground or on Boards. 
 Wheelbarrow : The simplest wheeled carriage is the barrow. 
 It consists of a body with two handles and one wheel. The 
 barrow used in Cornwall at the present day is not unlike that 
 figured more than three centuries ago by Agricola. It has 
 no legs, but in many ore-mines a barrow with legs is em- 
 ployed, somewhat resembling a navvy's barrow. Mine-barrows 
 are usually made of wood, and have either a wooden or a steel 
 wheel. The Cornish barrow is tipped sideways, whilst the barrow 
 with legs is tipped either sideways or over the end. This latter 
 form of barrow requires a higher and better level ; it is a more 
 advantageous appliance, as it throws a greater part of the load on 
 to the wheel and relieves the miner's arms to a certain extent. 
 The barrow often runs along the natural floor of the working- 
 place or level, but less labour is required if it is provided with a 
 road made of planks or strips of iron. 
 
 Carts and Waggons In the low passages, only 18 inches to 
 
HAULAGE OR TRANSPORT. 351 
 
 20 inches high (Fahrteri), leading from the working face of the 
 copper-shale mines at Mansfeld to the main roads, tiny waggons 
 on four wheels are employed. 
 
 Carts drawn by horses are used in some large underground 
 quarries. 
 
 A mine waggon largely employed in Germany at one time, ami 
 still seen occasionally, is the so-called Hungarian " Hund." It 
 has a rectangular body resting upon four wheels, two small -in 
 front and two large near the middle ; the workman presses down a 
 little handle at the back to make the load rest upon the two big 
 wheels only, and pushes the waggon along a board at the bottom 
 of the level. The Germans have also used four-wheeled waggons 
 running upon two boards ; and they were sometimes provided with 
 a projecting pin underneath which kept them upon the track. 
 
 B. Vehicles Running upon Rails. The points to be con- 
 siderd are (a) the road ; (b) the waggons ; (c) the power employed 
 for traction. 
 
 (a) Railways. Cast-iron tram-plates were introduced in the 
 last century, and were succeeded by wrought-iron rails ; these in 
 their turn are being superseded by rails made of steel. Various 
 forms of rails are in use. The simplest is a bar of iron set on 
 its edge, or a strip of flat iron nailed to longitudinal sleepers. 
 Rails of the former kind are made, for instance, of bars f by 2 J 
 inches, or J by 2| inches, fixed by wooden wedges in slits cut in 
 the sleepers. This rail has the disadvantage of wearing a groove 
 in the flange of the wheel, but it is easily and quickly laid and 
 readily bent into curves. Rails made of bars of round iron are 
 used in some Welsh slate quarries. 
 
 The bridge-rail was in great favour at one time, either laid 
 upon longitudinal or cross sleepers ; but nowadays flanged 
 T-headed rails made of steel are preferred. Care should be 
 taken to have strong and well-laid lines, especially where there is 
 likely to be much traffic. In this, as in many other depart- 
 ments of mining, it is very bad 
 
 economy to cut down the ori- FlG - 397- FIG. 398. 
 
 ginal expenses too much. What 
 is saved on the first cost will be 
 spent over and over again in 
 repairs, to say nothing of the 
 loss of time and money caused 
 by delays in the traffic. 
 
 The gauge varies from 14 
 inches to 3 feet or more ; 20 
 inches to 22 inches is a common '-.' '. ' ~ ~~ J -" 
 
 gauge in vein mining. The 
 
 weight of the rails for such roads is from 10 to 30 Ibs. per yard. 
 Figs. 397 and 398 show the sections adopted respectively by 
 Legrand of Mons and Howard of Bedford, for rails weighing 
 
352 
 
 ORE AND STONE-MINING. 
 
 1 8 Ibs. per yard. The rails may be simply spiked to wooden 
 sleepers, or they may be laid in chairs. In important roads fish- 
 plates should be used. 
 
 There is a tendency at the present day to adopt steel sleepers, 
 which are supplied by the makers to suit roads of various gauges. 
 They have proved to be very convenient and efficient, and in 
 this country they are cheaper in the end than wood. Among 
 their advantages are exact uniformity of gauge, easy and rapid 
 
 FIG. 399. 
 
 laying, fewer repairs. They are usually made of rolled steel, and 
 the rails are fixed either by clips, or by clips and keys. 
 
 One form of road supplied by Legrand of Mons (Fig. 399), has 
 the clips of one sleeper on the outside of the rail and those of the 
 next on the inside of the rail. The clips are firmly riveted to 
 the sleepers. In constructing the road, the sleepers B are laid 
 at suitable distances apart, exactly parallel to one another ; the 
 alternate sleepers A are then put in obliquely, as shown by the 
 dotted lines, and knocked into position with a hammer ; the 
 rails are joined by fish-plates. 
 
 Howard's sleeper (Fig. 400) is made from a plate of steel rolled 
 with a corrugation ; the lips which constitute the chairs for the 
 
 rails are formed by pressing 
 
 FIG. 400. down this corrugation with- 
 
 out cutting away any of the 
 metal. The jointing sleepers 
 have a double corrugation, 
 and the rails are fastened 
 with a simple key which 
 is serrated on one side. Some of Howard's sleepers for under- 
 ground work can be used without any keys. 
 
 Bagnall's sleeper is also distinguished by longitudinal corru- 
 gations which stiffen it and prevent its buckling. The Widnes 
 Chair and Sleeper Company prefer a section like that of a V-shaped 
 trough ; they claim that the penetration of this sleeper into the 
 ground ensures great stability. 
 
 Where a mine has a stock of old rails or old iron, it is often 
 more economical to convert it into sleepers than to sell it as scrap. 
 
HAULAGE OR TRANSPORT. 
 
 353 
 
 There are several methods in use. White * of Widnes utilises old 
 bridge rails (Figs. 401 and 401 a] by inserting two clips (Figs. 402 
 and 4020) into a piece of rail cut to the required length ; the 
 clip is held in place by a pin which passes into a hole punched 
 
 FIG. 401. 
 
 FIG. 401/7. 
 
 FIG. 40215. 
 
 in the sleeper. At the Llechwedd slate mine in North Wales, 
 two other methods have been devised by Mr. C. Warren Roberts 
 (Figs. 403 and 404) for utilising old channel iron and flat iron. 
 Stamped iron clips are riveted on so as to take the outer side of 
 
 FIG. 403. 
 
 ^^s^al.gr^&L, 
 
 r^t-^A.c^ea-. 
 
 FIG. 404. 
 
 JU, 
 
 o] 
 
 1 FEET 
 ft METRE 
 
 the flange of the rail, and similar clips are bolted on against the 
 inner flange. In order to allow for any small irregularity in the 
 width of the flange, the hole for the bolt is made oval, and this 
 enables the clip to be adjusted to the flange exactly. 
 
 * Engineering, vol. lv., 1893, p. 146. 
 
354 
 
 ORE AND STONE-MINING. 
 
 Points and crossings must be provided. The points may be 
 like those of an ordinary railway, with tongues moved by levers. 
 Another plan is to leave gaps between the rails where the lines 
 diverge or cross, and interpose plates of cast-iron upon which the 
 flanges of the wheels run without any difficulty. This arrange- 
 ment is suitable for cases where a man is pushing the waggon, for 
 he can turn it on to whichever road he chooses, but it will not 
 answer in the case of haulage by engine power. Each plate has a 
 rim or edge on the outer side, which prevents the wheels from 
 running off. 
 
 Flat plates are commonly used where there is a very sharp 
 bend in the road, such as when a cross-cut joins a level almost, if 
 not quite, at right angles. The plate is made of cast-iron with 
 ridges forming prolongations of the rails as shown in Fig. 405. 
 
 FIG. 405. 
 
 FIG. 406. 
 
 The waggon leaves the metals and the flanges of the wheels run 
 upon the plate ; as its surface is perfectly smooth, the waggon 
 is easily turned into the required direction, and the curved 
 ridges guide the wheels into the track which they have to 
 follow. 
 
 In places where there is a difficulty in procuring a casting, 
 the plate may be made of sheet iron, and the necessary 
 guiding ridges are formed by the overlapping ends of the rails. 
 The flange of the rail is cut away for a length of 8 or 9 
 inches and also part of the web ; the projecting piece of the head 
 is then hammered out so that the top of the rail slopes down 
 sufficiently to touch the plate. 
 
 Another device for guiding a waggon from a plate on to a 
 line of rails is a curved piece of round iron, i inch in diameter 
 (Fig. 406). The two ends are bent a,t right angles and sharpened 
 so that they can be driven into a sleeper at the edge of the flat 
 plate. The ridge formed by this piece of iron, guides the inner 
 bide of the flange of the wheel. 
 
HAULAGE OR TRANSPORT. 355 
 
 The inclination of the road is not without importance, because 
 there are usually waggons travelling in both directions, full ones 
 going towards the shaft or other outlet from the mine, and empty 
 ones returning to the working-places. The inclination down- 
 wards towards the shaft assists the work, but if it is too great the 
 return journey causes a useless expenditure of labour. 
 
 The rule in many ore-mines is to drive the levels as flat as 
 possible, with only just slope enough to make the water flow 
 away; the tendency of the workmen is always to rise too much, 
 and one sometimes meets with old levels where, through careless- 
 ness or inattention of the agent, the loss of level is very consider- 
 able. An inclination of J to J inch per yard, or i in 216 to i in 
 288 is common. 
 
 The condition of the road between the metals deserves more 
 attention than is usually bestowed upon it. There is unneces- 
 sary labour on the part of the man or the horse employed in 
 traction, if the road upon which he walks presents obstacles 
 through great unevenness. I have seen roads which were simply 
 a succession of deep puddles between the sleepers, a striking con- 
 trast to the well-kept main levels at the Mansfeld copper mines. 
 These levels are carefully paved with artificial stones, made from 
 slag ab the Company's smelting works. The paving-stones are 
 about 5 inches square at the top and 6 inches deep ; they are 
 also sold to the public, at prices varying from fcZ. to id. each. 
 
 (b) Waggons. Mine-waggons are made of wood, iron or steel. 
 They consist of a body or box resting on a frame carried by four 
 wheels. They vary greatly in shape and size according to the 
 nature of the excavation and the kind 
 of material transported. FIG. 407. 
 
 Figure 407 represents the plain but 
 strong waggon of the Van Mine, 
 Montgomeryshire, with a rectangular 
 body of sheet iron, an oak frame and 
 cast steel wheels. The top is strength- 
 ened by a band of flat iron. The 
 wheels are uj inches in diameter and 
 are just low enough to go under the body ; they are therefore 
 protected from blows, to which they would otherwise be liable 
 from stones dropping during the process of filling. The waggon 
 is emptied by being run in to a " tippler," that is to say, a cage 
 turning on pivots, which enables it to be completely overturned. 
 
 At the Mansfeld copper mines the general shape is similar. 
 Formerly waggons of various shapes and sizes were in use, but 
 now one uniform model has been adopted. The body is made of 
 sheet-iron J inch thick, and the upper edge is strengthened by an 
 iron band ii inch thick and 2j inches wide, whilst the corners 
 are stiffened with angle iron. The body is 3 feet 5^ inches long, 
 2 feet 2 inches broad, and i foot io| inches deep inside. The 
 
356 ORE AND STONE-MINING. 
 
 capacity of the waggon is 13 cubic feet, and it carries io cwt. 
 The body rests upon two pieces of iron placed lengthwise, 
 across which are fixed the two axles. The wheels are of chilled 
 cast-iron with special grease-boxes. The gauge of the road is 
 19 J inches, and the wheels are u| inches in diameter, so that 
 they can be placed under the waggon. The total height of the 
 waggon is 3 feet i inch, and it weighs 716 Ibs. 
 
 \Vhen made of sheet-iron or steel the sides can be bent, as 
 shown in Figs. 408 and 409, and larger wheels can be employed 
 without unduly raising the body. 
 
 In order to suit the small levels of some vein mines, the waggons 
 are made long and narrow. In the Isle of Man, one meets with 
 waggons 6 feet long and only 19 to 21 inches wide at the top ; 
 the depth being 2 feet. The sides slope inwards so that the bottom 
 is only 13 inches wide by 4 feet 9 inches, or 5 feet long. The 
 waggons are made of sheet steel about T \ inch thick, or of i| inch 
 
 FICJ. 408. FIG. 409. 
 
 plank. The discharge is by a door at one end, kept in its place 
 by a bolt. When the waggon has to be emptied, the miner 
 knocks up this bolt and lifts the waggon up behind till it slopes 
 enough for the "stuff" to run out. The top of the steel waggons 
 is stiffened by a band of J-inch iron 2 inches wide firmly riveted 
 on, and pieces of angle-iron, where the plates come together, give 
 a further amount of strength. Wooden waggons have the 
 bottom lined with sheet-iron | inch thick. 
 
 The diameter and nature of the wheels vary. At one mine 
 in the Isle of Man the wheels are io| inches in diameter, and run 
 loose upon the axles, which are bolted" to the frame under the body ; 
 they are 1 5 inches apart, from centre to centre. The wheels are 
 brought close together with a view of making the waggons pass 
 round curves without trouble. In order to render the tipping 
 easy, the centre of the front axle is placed 6 inches in front of the 
 middle of the waggon ; the miner, therefore, has the greater part 
 of his load balanced when he pivots his waggon on the axle of the 
 front wheels in the act of discharging it. 
 
 At a neighbouring mine under very similar conditions cast- 
 iron brackets are bolted under the body to receive the two axles 
 to which the wheels are firmly keyed, but the hinder axle is not 
 
HAULAGE OR TRANSPORT. 357 
 
 in any way attached to the bracket ; when it is desired to empty 
 the waggon, the hind end is lifted up and both sets of wheels 
 remain on the ground. The hind axle is made fast to the front 
 one by a couple of straps, for otherwise the hind wheels might run 
 away when the waggon was emptied. A disadvantage of this kind 
 of waggon is that it may require two men to replace it on the 
 road if it comes off; one may be wanted to see that the wheels 
 will drop properly on to the rails, while the other is managing 
 the body. 
 
 In both these waggons the wheels project outside the body, 
 instead of being underneath it out of harm's way, but they are 
 protected to a certain extent by the overhanging sides, and they 
 can be further screened by riveting on little shields of sheet-iron. 
 The lateral position of the wheels reduces the height of the waggon 
 required for any given capacity, a decided advantage when it has 
 to be filled with the shovel ; but in ordinary vein mining the ore 
 ought to be drawn down from shoots, and therefore the benefit of 
 easier shovelling comes into play only when loading rubbish or ore 
 in such places as the " ends." 
 
 In some mines the mineral is loaded in the level into an iron 
 bucket (kibble) standing upon a trolley, which is merely a small 
 platform upon four wheels. This trolley is pushed (trammed) to 
 the shaft ; the full kibble is hooked on to the winding rope and 
 drawn up, whilst an empty kibble is placed upon the trolley and 
 trammed along the level to the spot where it is again loaded from 
 a shoot or by the shovel. 
 
 Wheels for mine-waggons generally have a single flange, and 
 are made of ordinary cast-iron, chilled cast-iron, cast-steel, or 
 forged steel. Steel and chilled cast iron are the materials most 
 in favour; both have advantages. The wheels made of chilled 
 cast-iron are rather heavier than those of steel, and are brittle ; 
 the flange, for instance, will break under a blow which will not 
 damage a steel wheel; but a pair of chilled wheels will often 
 outwear several pairs of steel wheels if they happen to escape 
 the hard raps to which mine-waggons are liable. 
 
 Under Eyre's patent, wheels are made by forging a steel 
 bloom under a steam-hammer into dies; they are reported to 
 give great satisfaction and to be capable of standing much knock- 
 ing about. 
 
 Wheels with two flanges are used in the Festiniog slate mines, 
 and are considered best fitted for the work on account of the sharp 
 turns in the roads. 
 
 Much difference of opinion and practice exists concerning the 
 attachment of the wheels. Four systems are in vogue : axles 
 fixed and wheels running loose on them; wheels fixed to the 
 axles, which run loose in pedestals attached to the frame or to 
 the body of the waggon ; thirdly, a combination of these two 
 systems viz., wheels running loose on the axles and axles run- 
 
358 ORE AND STONE-MINING. 
 
 ning loose in the pedestals ; fourthly, one wheel fast on the axle, 
 and the other loose. 
 
 At a first glance it might be thought that it would undoubtedly be 
 best to follow the lead of the great railways, and have the wheels 
 fixed to the axles, because experience has shown that this system 
 answers so well above ground. Nevertheless, it must be remem- 
 bered that the conditions of underground roads are often very 
 different, the curves are frequently of very small radius, and 
 there is usually more difficulty in keeping the roads in perfect 
 order. By allowing the wheels and axles both to be loose, the 
 Festiniog miner, for instance, who may be tramming out a 
 block of slate 18 feet long, can slew his load on the truck 
 and so pass round sharp curves which would oppose an insur- 
 mountable obstacle if the wheels or axles were fixed. Loose 
 wheels with loose axles look clumsy and unnatural, and in spite 
 of all that may be said in their defence, it is probable that it 
 would in many cases pay the mine owner to improve the condition 
 of his roads and so render a more stable form of waggon 
 available. 
 
 Lubrication of the bearing parts is too often performed in a 
 perfunctory and wasteful manner, especially in mines where the 
 waggon never comes to the surface except for repairs. A little 
 grease or oil applied at the beginning and in the middle of the 
 shift is all that is considered necessary. Such a procedure must 
 be defective ; either there is too much of the lubricant at first, or 
 there is too little after the waggon has been in use for a time. 
 
 An automatic lubricating apparatus is sometimes fixed in the 
 road and every waggon is greased in going over it. The appa- 
 ratus consists of a wheel placed in a trough containing the 
 grease, and as each axle touches this wheel it receives a little 
 lubricant. A defect of these lubricators is that when a waggon 
 is going at great speed, as is the case with some systems of 
 underground haulage, the grease is flung about and wasted ; 
 besides, where a bearing can be greased in this manner it 
 is necessarily exposed to the dust or mud of the mine, which 
 must cause wear and friction. It is better to provide constant 
 lubrication and to protect the bearing parts as much as possible 
 from dirt. 
 
 One method by which this object is attained is shown in Figs. 410 
 and 411, which represent a waggon used at some collieries at Saint 
 Etienne, in France, and embodying the results of long experience. 
 The wheel, which is made of steel, is placed under the waggon, 
 and the journal is encased in a chamber kept full of oil. The 
 chamber has two holes which serve for passing in the linch-pin 
 and putting in the oil. They are afterwards closed with plugs. 
 Other points which may be noticed about this waggon are its 
 shape and mode of construction. The body is oval and made up 
 of wooden staves like a barrel. 
 
HAULAGE OR TRANSPORT. 
 
 359 
 
 As an example of a waggon constructed entirely of steel, 
 I take a "tram" designed for the Llanbradach colliery by 
 Mr. Galloway (Figs. 412 and 413). The body has the form 
 
 FIG. 410. 
 
 FIG. 411, 
 
 SCALE OF FEET 
 
 SCALE OF DECIMETRES 
 
 of a very blunt oval; it is made of sheet steel -$% inch thick, 
 stiffened round the top by channel steel. The wheels are fixed 
 to the axles, which are kept constantly lubricated by Stauffer's 
 lubricators placed immediately above them in the hollow axle- 
 
ORE AND STONE-MINING. 
 
 boxes The empty waggon weighs 12 cwt. and will carry 2 tons 
 of coal, when the load is built up higher than the sides. 
 
 When dealing with a tender mineral like coal, which decreases 
 in value if knocked about, it is important to reduce the effects of 
 bumping to a minimum; and with this object in view the waggon 
 
 E-g-sgqa 
 
 r 
 
 ^e- 
 
 rests upon springs and the buffers are elastic. The conse- 
 quence is that the waggon runs very smoothly, and is likely to 
 require less expenditure for repairs than one constructed in the 
 ordinary fashion without these appliances. There will likewise 
 be a diminution in the quantity of dust dropped on the road, a 
 matter of moment in collieries. 
 
HAULAGE OR TRANSPORT. 361 
 
 The Hardy Patent Pick Company makes self-oiling pedestals 
 for waggons with the wheels fast upon the axles (Fig. 414) ; 
 a is the upper part of the pedestal, and b the lower part, 
 containing felt or wool saturated with oil. This presses lightly 
 against the axle and keeps it oiled 
 for several weeks, without re- 
 quiring any attention. 
 
 It will be seen from these 
 remarks that a number of points 
 have to be considered in design- 
 ing a mine-waggon. They may 
 be summed up as follows : 
 
 Smallest weight compatible 
 with strength. 
 
 Small height, if the waggon is to be filled with the shovel. 
 
 Protection of the wheels from injury. 
 
 Constant lubrication. 
 
 Adoption of a uniform type of waggon for the mine. 
 
 Material which causes the least expenditure for repairs. 
 
 Easy handling and easy replacement upon the rails. 
 
 In a few exceptional cases the mineral raised in the mine does 
 not require a box or chest. This happens with slate, for the 
 blocks are brought up on trucks to which they are made fast by 
 chains, 
 
 (c) Power used for Underground Transport. 
 
 The sources of power are as follows : 
 
 1. Men, boys, women, and girls. 
 
 2. Horses, ponies, donkeys, and mules. 
 
 3. Gravity acting upon the material moved. 
 
 4. Machines driven by steam, water, compressed air, and elec- 
 
 tricity. 
 
 1 . Human Labour. Female labour underground is prohibited 
 by law in the United Kingdom, and no doubt it is destined to 
 disappear in other countries. We need only deal with men and 
 boys. Where the passages are high enough to take waggons 
 standing 3 feet above the ground, men are usually employed for 
 di-awing or pushing them. It is convenient to have waggons small 
 enough to be handled by one man, and also to be put back on 
 to the road by one man, if by chance they leave the rails. 
 
 The large waggons and loads at Festiniog require two men, 
 for the load of rubbish commonly amounts to if or 2 tons. The 
 waggon and load together may weigh as much as 2^ tons. The 
 men who push out these waggons usually do the loading also, 
 shovelling in the small pieces and lifting on the large ones. 
 
 2. Animal Labour. Traction by horses or ponies is cheaper 
 than using human power, but it is not always practicable to 
 
362 ORE AND STONE-MINING. 
 
 employ it. There are many ore mines in which it would be 
 impossible to lower a horse down the shaft ; and even where the 
 descent could take place, there would often be the further draw- 
 back, that as the work proceeds with comparative slowness, owing 
 to the hardness of the rock, there would not be " stuff" enough 
 broken in a given time to keep a horse constantly employed at 
 any particular level, whilst shifting it from one level to another 
 would entail much difficulty. 
 
 The load drawn by a horse at the Festiniog slate mines is as 
 much as eight waggons, a gross weight of 20 tons, or net weight of 
 1 6 tons, along a road with an inclination of fa inch per yard. 
 
 Where a mine is entered by a shaft, the horses are stabled 
 below ground, and much care is taken in many instances to 
 provide proper accommodation for them. The stables are paved 
 with bricks or concrete, sloping towards a gutter ; each horse has 
 its stall, or a loose board is hung between every horse and its 
 neighbour. Clean water is at hand for drinking. At a French 
 colliery I found the daily allowance of food to be as follows : 
 
 Oats lokil. (22lbs.) 
 
 Chopped hay from lentil and rye grass . 5 kil. (n Ibs.) 
 Bran. . . , . . . . 2 kil. (4-4 Ibs.) 
 
 In addition each horse had 5 kil. (n Ibs.) of straw per day as 
 litter. 
 
 The horses do not always belong to the mining company ; at 
 Festiniog, where the workings can be entered by adits, horses are 
 hired from persons in the district, who supply a horse and man 
 for eight shillings per day, and pay all the cost of food and 
 stabling. 
 
 3. Gravity. In working stratified deposits, it is often necessary 
 or convenient to lower a waggon down an inclined plane made 
 along the dip. At Mansfeld, for instance, instead of maintaining 
 a number of levels at short intervals apart, it is more economical 
 to reserve only a few for traffic, and abandon certain portions, 
 as already pointed out in Chapter VI. The waggons then 
 have to be lowered from the working level to one which is 
 kept up as a main roadway. Inclines for this purpose have 
 two lines of rails, one for the descending and the other for 
 the ascending waggon. A wire rope or a chain passes round 
 a pulley or drum at the top, the axis of which may be 
 horizontal or at right angles to the plane of the deposit. 
 Each end of- the rope can be hooked on to a waggon, and 
 the weight of the full waggon going down suffices to raise the 
 empty one. The speed is regulated by a brake on the pulley 
 or drum. 
 
 Another method of working inclines is to make the full 
 waggon draw up a weight, running on a special line of rails, 
 which is heavy enough to bring up the empty when it de- 
 
HAULAGE OR TRANSPORT. 363 
 
 scends. In order to economise space, the line of rails for the 
 weight may be made narrower than the one used for the waggon, 
 and may be laid between the two main rails. 
 
 If the incline is steep, a carriage with a horizontal platform is 
 provided. The mine- waggon is pushed on to this travelling 
 platform and ascends or descends in its ordinary position. 
 
 4. Machinery. Underground haulage may be carried on 
 either by travelling engines or stationary engines. 
 
 Locomotives fired with coal have the great disadvantage 
 of polluting the air by the products of combustion, consequently 
 they are not available unless the ventilation is very good, nor 
 unless there is absence of inflammable gases and freedom from 
 the risk of setting fire to the timbering or to the mineral itself. 
 A small locomotive of two horse-power nominal is used on an 
 iSJ inch track in the long adit of the Great Laxey lead and 
 zinc mine in the Isle of Man ; and at Rio Tinto in Spain a much 
 larger engine plies in the adit on a line with a gauge of 3 feet 6 
 inches. 
 
 Locomotives driven by compressed air, carried in a reservoir 
 upon a tender, improve the ventilation instead of injuring it, and 
 are not a possible source of danger from fire ; but, except in 
 special cases, they cannot be worked so cheaply as engines fired 
 with coal. However, the advantages they afford have led to their 
 adoption in some mines ; Lishman and Young's air locomotive 
 is employed in several collieries in the North of England. 
 
 To overcome the inconveniences and dangers of engines of the 
 ordinary type, fireless locomotives have been proposed and con- 
 structed. That of Lamm and Franck has a cylindrical reservoir, 
 instead of the boiler, filled three-quarters full of water. The 
 reservoir is heated by steam from the surface, until it is capable 
 of giving off vapour with a pressure of 235 to 294 Ibs. per square 
 inch (16 to 20 atmospheres). As the temperature and conse- 
 quently the pressure of the steam supplied by the reservoir are 
 constantly falling, a regulator is interposed between the 
 reservoir and the steam cylinder, which enables both the pres- 
 sure of the steam and the amount of expansion to be changed at 
 will. This arrangement renders extra power available if a steep 
 gradient has to be mounted. 
 
 Rolland's fireless locomotive is similar.* His reservoir has a 
 capacity of 19 \ cubic feet (0.550 cb.m.), and contains water at a 
 temperature of 205 C., or with a pressure of 235 Ibs. per square 
 inch (16 atmospheres). M. Rolland states that his locomotive, 
 charged in this fashion, will run for 2 to 2 J miles (3 to 4 kms.). 
 When going at a speed of 2 m. (6 feet 6f inches) per second, the 
 locomotive exerts 6 h.p. ; the speed of a horse may be taken as 
 0.9 to i m. (3 to 3 J feet). The locomotive ready for work weighs 
 three tons. 
 
 * B. and h. Zeituny, 1890, p. 375. 
 
364 ORE AND STONE-MINING. 
 
 As pointed out by Holland, the fireless locomotives have the 
 following advantages in addition to being more economical : 
 
 No danger of fire and ho inconvenience from smoke. 
 
 Improvement in the atmosphere of the mine, owing to absence 
 of the horses and their droppings. 
 
 The Honiginann * locomotive depends upon the fact that a 
 solution of caustic soda, of a certain strength, will absorb steam 
 and give out heat. This heat is utilised to convert hot water 
 into steam, which works an engine and then passes into the soda 
 solution, causing a further development of heat. The process of 
 steam-making goes on thus of itself, until the soda solution 
 reaches a certain stage of dilution. The locomotive is re- 
 stored to a state of activity by bringing back the solution to 
 the proper degree of saturation. This is done by passing steam 
 from a stationary boiler through coils of tubes in the reservoir 
 containing the soda, a process occupying little time. 
 
 Experiments have been made, and will be continued, with the 
 Honigmann soda locomotive, and also with Krauss' tunnel 
 locomotive, at the Mansfeld copper mines. 
 
 Stationary Engines. An enormous amount of underground 
 traffic is carried on by some system in which the power for 
 haulage is derived from an engine placed above or below ground ; 
 but the practice is far more developed in collieries than in vein 
 mines, where the quantities of mineral to be handled are as a rule 
 very much smaller. 
 
 With reference to the application of the power itself, the 
 various systems of underground haulage might be classified thus : 
 
 Steam or water power at the surface, \ i. Ropes. 
 
 transmitted to machinery under- > 2. Compressed air. 
 
 ground by . . . . . J 3. Electricity. 
 Water power below ground driving the machinery. 
 
 S,ea m power below ground driving ttof '' * 
 
 (2. Boilers below ground. 
 
 Petroleum engine below ground driving the machinery. 
 
 The subject of the transmission of power has already been 
 sufficiently discussed in Chapter IV., and need not be dealt with 
 here, save that it is necessary to point out that the conditions 
 of the problem are not the same when power has tc be applied 
 to haulage, as when it is required in a constantly changing 
 working face. As the mineral has to be brought to the shaft, the 
 engine and its boiler, if necessary, can be placed in the immediate 
 vicinity of the pit-bottom and the exhaust steam can be got rid of 
 without interfering with the comfort of the men or injuring the 
 condition of the workings. Proper rooms can be made for the 
 
 * Official Catalogue of Royal Mining, Engineering, and Industrial Exhi- 
 bition, Neiccastle-on-T/jne, 1887, p. xxxvi. 
 
HAULAGE OR TRANSPORT. 365 
 
 engine and the boiler, coal can be brought down and the ashes 
 removed without difficulty. Everything can be arranged in a 
 permanent and substantial fashion, so that steam power .may be 
 generated for haulage purposes below ground when it would not 
 be practicable to employ it for breaking down the mineral. 
 Again, when power has merely to be transmitted down a vertical 
 shaft in order to work a drum near the bottom, endless ropes may 
 be used, although they would be quite out of place if they had to 
 be carried along narrow, low, and crooked levels. For subsidiary 
 haulage purposes that is to say, for bringing trams from the 
 immediate vicinity of the workings to a main line Galloway 
 employs a small engine with two drums placed upon a waggon, 
 which is small enough to go into the cage and which will run 
 upon its own wheels along the underground railways. It can 
 therefore be moved about as required, and when coupled up to 
 the compressed air main can be set to work immediately to haul 
 out trams, instead of employing horses for this work. 
 
 We will suppose that the question of the most suitable driving 
 machinery has been settled according to the circumstances of the 
 case, and that the miner has to consider how he will apply it 
 to the transport of mineral. 
 
 Five systems are in use : 
 
 i. Single rope, 
 ii. Main and tail ropes, 
 iii. Endless rope, 
 iv. Endless ch*in. 
 v. Electric railways. 
 
 i. Single Rope. This system is available with a road 
 sufficiently inclined for the empty waggon to run down of itself, 
 after the load has been brought up, and draw back the rope with 
 it. One road will suffice, and the machinery required will be 
 some kind of drum, around which the rope is coiled, and an 
 engine for driving it. 
 
 The drum is usually placed horizontally ; it is provided with a 
 brake, and there is a disengaging clutch by which it can be thrown 
 in or out of gear with the engine. A pair of horizontal engines, 
 which have their cranks upon the drum-shaft, or which drive it 
 by means of a pinion and spur wheel, form the common method of 
 applying the power. 
 
 The wire rope has one end fixed to the drum and the other 
 is provided with a hook of some kind ; this is attached to a link of 
 the coupling chain of the truck and the load is drawn up. On 
 reaching the top of the incline or engine-plane, the waggon is 
 unhooked, and either pushed or allowed to travel of itself, under 
 the action of gravity, to the pit-bottom, where the onsetter runs it 
 on to the cage in which it is raised to the surface. 
 
 An empty waggon is then hooked on and run on to the incline, 
 and the engine-rnan, with his brake under proper control, dis- 
 
366 ORE AND STONE MINING. 
 
 engages the drum by means of the clutch and lowers the load 
 without using any steam. When worked in this way, the incline 
 requires only one line of rails. A series of rollers have to be put 
 in for the purpose of keeping the rope from trailing on the ground 
 and of thus preventing much unnecessary wear and friction. These 
 rollers are small wooden, cast-iron, or steel cylinders, often with a 
 low flange at each end to keep the rope in its place ;. they are laid 
 horizontally and are capable of revolving around a horizontal 
 spindle. Care is, or ought to be, taken to see that they are very 
 correctly set and that they are well lubricated, so that they may 
 revolve freely when the rope is drawn over them ; otherwise the 
 strands are sure to be worn down rapidly from rubbing against 
 them. 
 
 The incline may also be worked with two lines of rails, after 
 the fashion of the self-acting inclines ; and this system has the 
 advantage of being more economical, for the deadweight of the 
 loaded waggon coming up is balanced by the weight of the empty 
 one going down. It is not even necessary to have two lines all 
 the way ; provided there is a sufficient length of double line where 
 
 FIG. 415. 
 
 the waggons meet, the incline can be worked with a length of 
 single line at the top and a similar length of single line at the 
 bottom. To prevent a waggon from running down in case a 
 coupling link or the rope should break, a safety appliance, called 
 a backstay, may be attached to it. It is a sort of fork which hangs 
 behind the waggon, and just touches the ground ; if the rope 
 breaks, it digs itself into the road and prevents the waggon from 
 going down. Of course it can only be used while the waggons are 
 being raised, but it is during the journey of the loaded waggon 
 that the rope is most likely to break. 
 
 ii. Main and Tail Ropes. On the engine planes just 
 described, the empty waggon goes back under the action of 
 gravity ; but with very slightly inclined, flat, or undulating roads 
 this is impossible. One method of getting over this difficulty is 
 to add a rope, called the " tail rope," which will draw the empties 
 back ; the rope which draws the full waggons is known as the 
 " main rope." 
 
 The system is perhaps best explained by a diagram (Fig. 415) : a 
 is a drum upon which is coiled the strong main rope ; b is another 
 drum upon which is coiled the tail rope, passing round the pulley c. 
 The waggons are coupled together and form the train or " set," 
 which may in reality consist of as many as TOO waggons. Suitable 
 clutches enable either drum to be worked at pleasure by the 
 
HAULAGE OR TRANSPORT. 367 
 
 engine, while the other is allowed to run loose upon the shaft. 
 Each drum has a brake, by means of which the rope can be 
 prevented from becoming too slack while uncoiling itself. When 
 the drum a is made to revolve by the engine, the main rope 
 is wound up, the drum b running loose, and the train or ''set" 
 is drawn from c to a. Here the waggons are uncoupled and 
 pushed to the shaft, or, better, the station at a is arranged so 
 that it is sufficiently high for the waggons to run down of them- 
 selves under the action of gravity. A new train of empties is 
 then made up, the tail and main ropes are attached to it and the 
 drum b is set in motion so as to wind up the tail rope and draw 
 the waggons into the terminus at c. It will be evident from a 
 glance at the figure that the tail rope must be twice as long as the 
 main rope. As the tail rope has simply a train of empties to haul 
 out, it may be made smaller than the main rope, except in cases 
 where the road has a downward inclination towards the shaft 
 sufficient to cause the loaded train to run down of itself and draw 
 the tail rope after it. 
 
 A single line suffices for this system of haulage; the main 
 rope lies in the middle of the road, resting upon a series of 
 horizontal rollers similar to those used upon ordinary inclined 
 planes. Where there are curves, however, the rope must be 
 guided by small vertical rollers. The tail rope is brought along 
 the side of the road, or if more convenient, along a separate road, 
 also resting upon rollers or pulleys and suitably guided at the 
 curves. The system is applicable to roads of varying gradients, 
 and arrangements can easily be made for working branches, by 
 having a special piece of tail rope in each branch going round a 
 pulley at the end of it. When mineral has to be drawn away 
 from the branch, the piece of tail rope on the main road beyond 
 the junction is cVsconnected, and the piece belonging to the 
 branch is attached. Traffic then goes on as before, save that the 
 train is made up in the branch. Another plan is to disconnect 
 the tail rope at the end of the train, and couple one end of the 
 branch rope to the train and the other to the free end of the 
 ordinary tail rope. During the running of a train the tail iope 
 then goes round the pulley at the end of the main road, passes 
 round another at the junction of the two roads, proceeds along 
 the branch round its terminal pulley, and back to a pulley which 
 again puts it into the direction of the main road. 
 
 The trains are in a large number of cases made to run at a 
 great speed, even as much as 10 or 15 miles or more an hour, and 
 if by some mischance an accident does happen from one of the 
 waggons getting off the road, a good deal of damage may be done 
 to the train and roadway. 
 
 iii. Endless Rope. A favourite method of underground 
 haulage is by an endless rope passing round a pulley at each 
 terminus, and generally travelling continuously in the same 
 
368 ORE AND STONE-MINING 
 
 direction. The rope is kept in a state of tension by 
 passing it round a tightening sheave, which in some instances 
 is one of the terminal pulleys. The tightening sheave or 
 pulley is carried by a frame running upon wheels, and is 
 constantly drawn back by a heavy weight. The necessary grip of 
 the rope is obtained by coiling it several times round the driving 
 drum, or around a driving pulley with grooves and a second 
 grooved pulley close by ; the rope wraps itself, for instance, upon 
 three half circumferences of one pulley and two of the other. 
 The speed of an endless rope is usually from two to three miles an 
 hour, though instances might be cited of as low a speed as one 
 mile an hour. The endless rope system admits of so many modi- 
 fications that it is necessary at once to classify them before 
 entering into any details. We may begin by making two broad 
 divisions : * 
 
 Waggons attached singly at intervals along the rope. 
 Waggons attached in groups or trains (sets}. 
 
 Waggons Attached /Singly. Two distinct lines of rails are 
 required, because there is a constant stream of full waggons 
 coming out to the shaft and a constant stream of empties going 
 into the workings. 
 
 This class has two subdivisions : 
 
 Eope above the waggons. 
 Hope below the waggons. 
 
 When the rope is above the waggons, no rollers are necessary 
 except at the curves. Several modes of attaching the waggon to 
 the rope are in use. 
 
 If the gradient is all up hill a very simple clip is sufficient. 
 The rope is made to rest in a fork on the waggon, and as it 
 is bent slightly out of the line of pull when in motion, it is 
 held tightly enough by friction to draw along the load. If the 
 gradient varies, a fork is put on each end of the waggon, or a 
 screw clip is employed ; this resembles a pair of tongs, the jaws 
 of which are brought tightly together by a screw worked by a 
 handle, and hold the rope with a firm grip. 
 
 Another common attachment is by a piece of chain 6 or 8 feet 
 long with a hook at each end. A boy puts one hook into an eye 
 on the drawbar of the waggon, and giving the other end of the 
 chain four turns round the rope makes it fast in the hook. 
 To detach a waggon the boy presses down the chain near the 
 waggon, takes out the hook from the drawbar, and then unwinds 
 the other end from the rope. After a little practice the boys 
 become very dexterous in this hooking on and off, and perform 
 
 * The classification and some of the information is taken from the 
 Catalogue of the fiot/al Mining, Engineering, and Industrial Exhibition, 
 Ntwcastle-on-Tijne, 1887, p. xxxiv. 
 
HAULAGE OR TRANSPORT. 
 
 3 6 9 
 
 FIG. 416. FIG. 417. 
 
 these operations with great rapidity. If there is a downward 
 gradient the waggon would outrun the rope, and it is necessary 
 to put a chain at the rear end as well as in front. 
 
 When the rope is below the waggons, rollers are required on 
 the road, similar to those already described for engine-planes 
 and main and tail ropes. The attachment to the rope is made 
 by some form of clip. At the Hodbarrow iron mine in Cumber- 
 land, Rice's clutch (Figs. 416 and 417) has been used for many 
 years with good results. The rope can be put in or taken out 
 sideways after raising the sliding piece 
 A as far as the projecting pin. The clip 
 is hung by its hook on to the waggon 
 and the rope is lifted in ; the motion of 
 the rope draws the clip a little away 
 from the vertical, and this slight devia- 
 tion of the groove from the line of pull 
 gives sufficient grip for haulage. 
 
 The number of clips or clutches is 
 very great, and it would be useless to 
 attempt to describe them all within the 
 limits of this work. 
 
 An advantage of this system is the 
 smooth and regular manner in which it 
 works. The waggons are attached at 
 intervals of about 20 yards or even less, 
 and they arrive without the bustle of 
 a long train. The men and boys are 
 
 kept constantly employed, but have ample time for doing all that 
 is required of them. If a waggon goes off the line, it is true 
 that a large number of the succeeding ones may be thrown off 
 too, before the damage becomes known ; but the absence of a high 
 speed tends to render the consequences less perilous than with 
 the fast-running trains of the main and tail rope system. 
 
 Waggons Attached in Groups or Trains (Sets). As in the 
 previous case there are two subdivisions : 
 
 Rope above the waggons. 
 Eope below the waggons. 
 
 The former of these two methods is very easily understood. 
 For instance, several waggons may be coupled together and the 
 train thus formed is connected to the moving rope by a short 
 piece of chain with two hooks, in the manner described for a 
 single waggon. Other attachments are of course available. 
 The second subdivision admits of a great many varieties : 
 (a) Single road, with a siding or sidings for the full train to 
 pass the empty one. (ai) Single central siding. The rope is 
 arranged in the form of a double loop, represented diagramma- 
 tical^ by the dotted line (Fig. 418) ; S denotes the shaft end of the 
 
 2 A 
 
370 OLE AND STONE MINING. 
 
 haulage svstem, W the end near the workings, and C the centra] 
 siding. The full lines indicate the railroads. When moving in 
 the manner shown by the arrows, the rope brings out a train of 
 full waggons from the workings, and takes in a train of empties 
 from the shaft. On arriving at the central siding the rope is 
 stopped, the empties are shunted on to the siding, and the 
 
 FIG. 418. 
 
 train of full waggons is attached to the part of the rope which 
 has just brought in these empties. The empties are shunted 
 back on to the main line and attached to the part of the rope 
 just used for bringing out the full waggons. On reversing the 
 motion of the engine, the empties proceed to the workings and 
 the full train travels to the shaft. 
 
 (a2) One or more sidings. The two ropes (Fig. 419) lie 
 within the road, except at the sidings, each of which has one of 
 them. There are points at the ends of the sidings, for diverting the 
 trains on to the proper roads. Each train has a special truck, or 
 
 FIG. 419. 
 
 bogie, in front, upon which rides a conductor. It is his business 
 to pick up with a hook the rope he requires, and grip it with his 
 clutch ; his train then moves along on to the main line till he 
 comes to a pass-by. A boy attending to the points makes the 
 train take the proper line, and if one train arrives a little too 
 early for the passing, the conductor loosens his clutch and brings 
 his train to a standstill until the other train has gone by. He 
 can then proceed along the main road till it becomes necessary to 
 cross a second train. 
 
 (/3) Two roads formed by three rails with one or more sidings 
 for the passing of trains. One-half of the endless rope (Fig. 420) 
 
 FIG. 420. 
 
 lies in the middle of one track, and the other in the middle of the 
 other track. The trains pass as they did in the previous system ; 
 but there is the advantage that no points are required. 
 
 (y) Two entirely separate lines of rails. In this case (Fig. 421) 
 no intermediate sidings or points are necessary, for each train has 
 its own line> and the services of the conductor can be dispensed 
 with. 
 
HAULAGE OR TRANSPORT. 371 
 
 In making a choice between these various methods, much 
 depends on the nature of the roads. At some mines it may 
 be difficult to keep a road open of the width necessary for 
 two separate lines of rails, or indeed for one; so that a system 
 which can be worked by a single line with occasional sidings will 
 be preferred. Besides, it may be necessary to introduce mechanical 
 haulage into a mine laid out originally for horse traffic, and the 
 expense of making a second road might be fatal to a double-line 
 system, in spite of its manifest advantages. 
 
 FIG. 421. 
 
 iv. Endless Chain. This may be looked upon as a variety 
 of the previous system, a chain being substituted for the rope. 
 The chain is usually made to ride upon the waggons, and as 
 each link lies in a plane at right angles to that of its neigh- 
 bour, it is easy to devise a simple catch or clip. A common 
 one is a bar with a fork at the top, which is attached to one 
 end of the waggon. The waggon is pushed under the chain, which 
 is sagging down a little, so that a link lying vertically drops into 
 the fork ; the next link will catch against the clip and set the 
 waggon in motion. On arriving at the terminus the chain is 
 raised by a pulley, and so lifted out of the fork. The waggons 
 are attached singly. 
 
 v. Electric Railways. In the previous four cases we 
 have been dealing with the transmission of power by a moving 
 rope or chain, we now come to a totally different solution of the 
 problem viz., the transmission of power by a wire or wires to a 
 motor which runs on a track and draws a train of cars after it. 
 
 As an example * of an electric railway, I may take one which 
 has been running for some years at the Neu-Stassfurt mine, 
 where potassium salts and rock salt are the object of the workings. 
 The underground railway runs for a distance of nearly 1000 yards 
 (900 m.), along the strike of the deposit ; a cable is brought down 
 the shaft, and there are two insulated conductors hung from the 
 roof of the level ; one conveys the current to the electric locomotive 
 by means of a slide, dragged along by a small rope, and the 
 other has a similar slide for the return. The road in this case is 
 perfectly horizontal, and the locomotive draws a train made up 
 of 20 waggons. An empty waggon weighs 400 kil., and takes a 
 load of 750 kil.; 20 full waggons make up therefore a total 
 weight of 23 tons. The locomotive weighs 2*1 tons, consequently 
 the total weight of the train is about 25 tons. The steam 
 engine for driving the dynamo at the surface is of about 20 
 
 * MS. notes and B. und h. Zeitung, 1888, p. 300. 
 
372 ORE AND STONE-MINING. 
 
 horse-power. The locomotive is 3 feet J inch wide by 4 feet 1 1 
 inches high, and 8 feet 9 inches long between the buffers (930 ram. 
 by 1500 mm. by 2670 mm.) and the centres of the axles are 
 i8f inches (480 mm.) apart. The gauge of the road is 24! inches 
 (628 mm.), and the diameter of the driving wheels 13^ inches 
 (350 mm.). The locomotive is made alike at both ends, with a 
 seat for the driver, so that he can travel in either direction, with- 
 out having to turn it round. It takes a train five minutes to run 
 the 900 metres. 
 
 The cost compares favourably with that required for tramming 
 by men or horses, and in 1888 the figures given were as follows : 
 
 
 
 Electric Railway. 
 
 Horses. 
 
 Men. 
 
 Cost of haulage per ton > 
 per kilometre . J 
 
 Pfennige. 
 12-9 
 
 Pfennige. 
 I6'00 
 
 Pfeimige. 
 34-20 
 
 Speaking roughly these figures are i^d. per ton per kilometre 
 for the electric railway, i jd. for horses, and qd. for men. 
 
 Comparing the electric railway with horse traffic, there are 
 other advantages besides that of cost. The mine is kept much 
 sweeter and cleaner, from the absence of the droppings of the 
 horses, and in this particular case, the animals would suffer in 
 their hoofs, from constantly walking in the damp salt. 
 
 The Neu-Stassfurt line is not working under the most favour- 
 able conditions for economy, because it cannot be kept fully 
 employed ; and considering the rapid strides which have been made 
 during the last few years in electric transmission, it is certain 
 that a line put up nowadays would furnish more favourable 
 results. The line shown by Messrs. Siemens and Halske, at the 
 late Frankfort Exhibition, had a single wire hung from the roof 
 of the level, and the current was brought down to the motor on 
 the locomotive by a running pulley held by a balanced arm, which 
 ensured contact, although the distance between the wire and the 
 locomotive was not always exactly the same. The return current 
 travelled along the rails. 
 
 At Greenside mine in Westmoreland, there are two wires along 
 the roof of the level, one for bringing the current to the electric 
 locomotive and the other for the return. 
 
 VI. CONVEYANCE BY BOATS. This is a very excep- 
 tional method of conveying mineral underground at mines; but 
 it needs mention to make the subject complete. 
 
 In this country there is an adit level at the Tankerville 
 and Bog mines in Shropshire, known as the " Boat level," 
 because the ore was carried in boats to its mouth, a distance in 
 some places of i f miles. As the adit had been driven with too 
 great a fall originally, it was necessary to have small locks under- 
 
HAULAGE OH TRANSPORT. 373 
 
 ground, and so subdivide the whole length into several parts, one 
 {slightly above the other. This level now serves simply as a 
 drainage tunnel. 
 
 At the Dorothea Mine, near Clausthal in the Harfcz, there is a 
 level more than 400 yards below the surface, along which there 
 was at one time a large amount of traffic by boats. The level is 
 10 feet high, by 7 feet wide, with 5 feet of water in the bottom. 
 The boats used on this underground canal were about 31 feet 
 long, 4j feet wide outside, and 3 feet deep. The part used for 
 holding the ore had a capacity of about 220 cubic feet ; the load 
 was 5 or 6 tons of ore, and a full load would bring the edge 
 of the boat within 6 inches of the water. The boat was 
 propelled by the men, who pushed with their feet against the roof 
 of the level. 
 
 TRANSPORT ABOVE GROUND. 
 
 In commencing this chapter I said that it would be convenient 
 in this place to take the subject of conveyance of mineral above 
 ground, though, strictly speaking, it would not come until after the 
 consideration of methods of raising ore and rubbish to the surface. 
 This part of the subject must be treated in a somewhat summary 
 manner for want of space, and also for the reason that much that 
 has been said about underground traffic will apply in the case of 
 conveyance above ground, indeed the same heads may be taken, 
 with the addition of a seventh transport by aerial ropeways. 
 
 1. Shoots made of timber ? with the wearing parts protected by 
 iron, can be applied in places where there is a sufficient amount of 
 fall. In a hilly country it may sometimes be worth while sinking 
 a shaft solely for the purpose of using it as a means of dropping 
 ore to a lower level. 
 
 2. Flow along Pipes is made use of on a very extensive scale 
 for the transport of natural gas, petroleum and brine. 
 
 The Annual Report of the Philadelphia Company, one of the six 
 companies supplying Pittsburg, shows that in the year 1885 it had 
 331 miles of mains and distributing pipes, which brought in the 
 natural gas from distances of 22 to 24 miles; at that time it was 
 estimated that there were at least 500 miles of pipes coming into 
 the city. The mains vary in diameter from 3 inches to 30 
 inches, the largest sizes being made of cast-iron and the others of 
 wrought-iron. There are more pipes of 8 inches in diameter 
 than of any other size, and the mains are made to increase in 
 diameter as they approach the city, in order to reduce the 
 pressure of the gas. Many of the wells when shut would have a 
 pressure of 500* Ibs. per square inch, and even when the pressure 
 is far lower than this, it is necessary to reduce it in order to 
 prevent leakage, which means not only diminished profits to the 
 
 * C. A. Ashburner, " The Geologic Distribution of Natural Gas in the 
 United States." Trait*. Amer. Just. AI.E., vol. xiv. 1886, p. 428. 
 
374 OKE AND STONE-MINING. 
 
 company, but also danger to the consumer. In the town the 
 pressure nowhere exceeds 13 Ibs., and in many of the mains it is 
 not more than 6 or 8 Ibs., whilst in the low pressure mains it is 
 only 4 or 5 ozs. per square inch. 
 
 Another case of conveyance of gas by pipes is seen at the bore- 
 holes furnishing carbonic acid gas in Germany ; under its natural 
 pressure the gas flows through wrought-iron pipes, either to the 
 works where it is compressed into the liquid state, or to those 
 where it is utilised for the manufacture of white lead. 
 
 Crude petroleum, which either rises naturally to the surface or 
 is pumped up, has to be refined before it can be utilised com- 
 mercially, and it has been found convenient in many districts to 
 send the oil to the refineries by pipe-lines.* Pumps are employed 
 for forcing the oil through the long lines of pipes, as .there is no 
 natural pressure in this case. The United Pipe-lines Company in 
 America had, in 1886, "over 4000 miles of piping and 500 
 reservoirs, each holding from 20,000 to 30,000 barrels," f and 
 probably now there are more than 5000 miles of pipe-lines in the 
 United States. 
 
 The pipe-line from the LimaJ oil district of Ohio to Chicago is 
 210 miles long; the pipes are 8 inches in diameter, and each 
 piece 22 feet long. The cost of the pipes alone was estimated to 
 be $7000 per mile, and the total cost of the undertaking, in- 
 cluding the pumps and reservoirs, $2,250,000. 
 
 Another of the great American pipe lines connects Olean in 
 the Bradford oil-field with New York City. It consists of two 
 lines of 6-inch pipes, more than 300 miles in length, and it is 
 divided into 1 1 separate sections. At each station there are two 
 tanks and a pump ; when one tank is receiving oil, the other is 
 supplying it to the pump for transmission to the next station 
 further east, a week being required to complete the journey. As 
 the lines of pipes follow the irregularities of the surface, ample 
 pumping power has to be provided. One of the Worthington 
 pumps (j on this line exerts a pressure of 900 Ibs. per square 
 inch, and is capable of delivering 1,500,000 gallons in 24 hours. 
 
 Mr. Marvin also mentions a pipe-line at the Burmese oil-fields 
 made of lacquered bamboos, for taking the oil from the wells to 
 the river. Modest as this line appears compared with the great 
 undertakings just described, it is nevertheless an advance upon 
 the old plan of putting the petroleum into earthen jars, and 
 carting it. 
 
 In this country, brine is sent by pipe-lines from the wells 
 
 * Redwood, " Petroleum and its Products." Journ. Soc. Arts, xxxiv. 
 j886, p. 832; and " Cantor Lectures," published separately, p. 30. 
 f The Times, 29th September, 1886. 
 j Engineering, vol. xlv. 1888, p. 439. 
 
 C. Marvin, " England as a Petroleum Power," London, 1887, p. 19. 
 || Evg. Uin. Jour., vol. li. 1891, p. 745. 
 
HAULAGE OR TRANSPORT. 375 
 
 to convenient places for evaporation or to alkali works, where 
 it is used in making carbonate of soda by the Solvay process. 
 Lastly, it has been suggested that the solution of the " caliche," or 
 raw nitrate of soda, should be sent down in pipes to the coast 
 for evaporation, instead of performing this process in the arid 
 desert in the neighbourhood of the diggings. 
 
 The flow of mineral in suspension in water along troughs 
 (launders), or channels made in the ground, or pipes, is a process 
 which may be seen on the dressing- floors at metalliferous and other 
 mines, as well as at china clay works. At the Mechernich lead 
 mines the waste from the preliminary dressing-floors is forced by 
 plunger-pumps through a large pipe to pyramidal boxes, in 
 which the water is separated from the sand, so that it may be 
 used over again. 
 
 Though not a true flow, I may here mention the conveyance of 
 a mineral for short distances by revolving screws in troughs 
 (" screw conveyors "), which serve to transport a mineral from 
 one part of a factory or dressing-floors to another. 
 
 3. Human Labour. In mountainous districts where the 
 inhabitants are accustomed to carry their provisions, their hay 
 or other agricultural produce upon their backs, it is not unnatural 
 to find ore transported in the same way from the mine to the 
 dressing-works. Not many years ago, gold ore was regularly 
 carried to the little amalgamating mills in the Italian Alps on 
 women's backs. The ordinary load for a woman down hill was 
 100 Ibs. (45 kil.). If the woman took tools or materials up 
 hill, the load was naturally less, and amounted to about 75 Ibs. 
 (34 kil.). The ore was carried in a basket or creel (scivera), an 
 appliance to which every peasant-girl had been accustomed from 
 early youth. 
 
 Ore may be moved from one part of the dressing-floors to another 
 by hand-barrows. These are merely rectangular trays or boxes, 
 with a pair of handles in front and a pair behind. The hand- 
 barrow requires two persons to carry it (Fig. 6n). 
 
 Carriage on the head is met with in some countries. 
 
 4. Conveyance by Sledges. Sledges drawn by men or horses 
 still survive in some hilly districts. Even in Wales at the present 
 day, manganese ore is sometimes brought down from the mine to 
 the nearest cart-road in this primitive fashion. But it is a toil- 
 some and unsatisfactory method of transport, and justifiable only 
 in the case of trials, which have not yet proved a sufficient amount 
 of ore to warrant the construction of a tramway or a ropeway. 
 
 5. It is by wheeled conveyances that minerals are most 
 commonly transferred from one part of a mine to another, or 
 from the mine to a railway or port of shipment. Wheelbarrows 
 are applicable for distances measured by yards, such as one may 
 have on dressing-floors, and carts are sometimes the only available 
 means of transport for one or two hundred miles ; but the traffic 
 
376 ORE AND STONE-MINING. 
 
 should be conducted in some cheaper fashion, by railways for 
 instance, as soon as possible. 
 
 It is not necessary to go over all the old ground with regard to 
 rails, sleepers, points and crossings ; suffice it to say that though 
 the surface railway resembles the underground one, it is generally 
 better kept ; first, because its defects are more palpable to every 
 one by daylight than when seen by the glimmer of a candle, and 
 secondly, because there are fewer difficulties in laying it properly 
 and keeping it in order. 
 
 At the surface as well as underground we have self-acting 
 inclines, and traction by locomotives and ropes. 
 
 Self-acting inclines stand the miner in good stead in hilly 
 countries. There are either two entirely separate roads, one for 
 the full waggon going down and the other for the empty which is 
 being brought up, or there are three rails with a pass-by in the 
 middle, or even a single road, except at the pass-by. The incline 
 is worked by a drum at the top, placed most commonly on a 
 horizontal axis, and of course provided with a brake. 
 
 As examples of large inclines, I may refer to those erected 
 by the " Societe Franco-beige des Mines de Somorrostro," * for 
 bringing down iron ore to their railway, which then conveys it to 
 the port of Bilbao. The lower of the two planes is 737 yards 
 (674 m.) long, with an average inclination of 30, the maximum 
 inclination being 36 near the top. It is worked by steel wire 
 ropes i^ inch (38 mm.) in diameter, which are coiled around two 
 conical drums, united by their bases and having a mean diameter 
 of i6J feet (5 111.). In order to regulate the descent of the trains, 
 the drums are connected by gearing with an air-brake, identical 
 in principle with the fly of a clock (Fig. 422). It is composed of four 
 straight vanes made of wood and iron, about 6^ feet (2 m.) wide, 
 and i6J feet (5 m.) in diameter outside. Twelve waggons coming 
 from the mine are coupled together so as to form a train, and 
 when it starts down the incline, the air-brake begins to revolve 
 and soon develops a considerable amount of resistance as the speed 
 increases ; the consequence is that the train descends with an 
 almost uniform velocity. The strap-brake on the drum simply 
 serves to moderate the speed if necessary and to stop the train ; 
 but in no case is much power required to work it. The train 
 makes a journey in three minutes, and it takes three minutes to 
 make up and couple on a train ; therefore there is one train 
 every six minutes, and as each waggon contains two tons, the 
 quantity delivered by each train is 24 tons, or with ten trains an 
 hour the quantity per day of ten hours will be 2400 tons. By 
 increasing the number of waggons in each train, the day's work 
 
 * Exposition Universelle de 1889. Note sur ^Exposition de la ISociett 
 
 Franco-beige des Mines de /Somorrostro en 1889, Palis, 1889, p. II. Les 
 
 Grandes uswes de Tnrgan. August, 1889, p. 50. Forges et Ateliers de Con- 
 struction de Mme. Vve. Taza- Villain. 
 
HAULAGE OK TRANSPORT. 
 
 FIG. 422. 
 
 377 
 
3/8 ORE AND STONE-MINING. 
 
 may be run up to 2600 tons. The fan -regulator has the advan- 
 tage of saving the wear of the ordinary strap-brakes and of 
 rendering the speed uniform. If nothing but a strap-brake was 
 used, there would be a very great amount of friction, which might 
 cause the wooden shoes to take fire ; in any case it would 
 throw a great strain upon the machinery, and involve the risk 
 of a serious accident if it happened to break. The fan- 
 regulators avoid all these difficulties ; but they must be made 
 very strong, as they have to counteract a considerable amount of 
 vis viva at the particular incline mentioned no less than 428 
 horse-power. I have dwelt somewhat upon this fan-regulator, 
 as it has been found extremely serviceable at Somorrostro, though 
 little known elsewhere. 
 
 Locomotives burning coal can be used without inconvenience, 
 and effect a great saving in most places, when compared with 
 horse traffic. At the Fbstiniog slate mines, small locomotives 
 running on a track with a 23|-inch gauge are employed for 
 drawing trains of rubbish to the tips ; the total weight of a train 
 may be as much as 80 tons. As the men who are removing 
 rubbish from the underground or surface workings are paid by 
 the ton, the loads have to be weighed. When the trains are 
 drawn by a horse, it is necessary to stop each time a waggon is 
 brought on to the weigh -bridge ; but when the locomotive is used, 
 the train runs so smoothly that the waggons can be weighed 
 during their passage, without any halts being made. This is 
 a small advantage it is true, but it saves time and consequently 
 money, and should therefore be noticed. 
 
 The endless rope and the endless chain conveying single 
 waggons at stated intervals are both in favour, either for trans- 
 porting the valuable mineral to any required spot, or for taking 
 the waste to the tip or " dump." 
 
 An example of the former system may be seen at the De 
 Beers * diamond mine, South Africa, where the gem-bearing rock 
 has to be exposed to the action of the atmosphere for some months 
 in order to make it crumble away and become ready for the pro- 
 cess of washing. Large areas have to be covered with the " blue," 
 and cheap haulage is a matter of importance. The depositing 
 floors commence at a point a mile from the mine and extend 
 for three miles to the east and one mile to the west. The main 
 line is three miles in length and it has two branches, one a mile 
 long, and the other three-quarters of a mile long. The rope is 
 driven by a horizontal engine, with two cylinders, each 14 inches 
 in diameter, and having a stroke of 3 feet. It is | inch in 
 diameter and, as is very commonly the case elsewhere, it has an 
 iron instead of a hempen core, in order to prevent a reduction of 
 
 * De Beers Consolidated Mines, Limited. Second Annual Report for the 
 Year ending ^ist March, 1890, p. 17. 
 
HAULAGE OR TRANSPORT. 3 7 9 
 
 section when it is subjected to continued tension. It is carried 
 on the steel trucks, which can be tipped on either side, as the body 
 is supported on two trunnions (H, Fig. 442). The device for 
 attaching the rope to the waggon is very simple ; the rope lies 
 in a fork or " jockey," which is slightly out of the direct line of 
 traction. The jockey is free to turn in a socket on the truck, 
 and the slight bend given to the rope is sufficient to afford the 
 necessary grip, even in going up an incline of i in 20. If the 
 " blue " has to be deposited at a point nearer the mine than the 
 terminus, the part of the rope beyond the place where the waggons 
 are taken off is supported by pulleys. 
 
 Horses are employed to draw the trucks from the main rope 
 haulage lines to the places on the floors where they have to be 
 tipped. 
 
 The endless chain has been chosen for bringing down the ore 
 from some of the mines of the Somorrostro Company,* in a part 
 where self-acting inclines cannot be used because there is not a 
 descent all the way. A second reason for adopting this system 
 was the fact that it admits of considerable changes in the amount 
 of traffic, by altering the speed of the chain and the distance 
 between two successive trucks. It further allows branch lines 
 to be taken off from the main one. At Somorrostro there are 
 in all very nearly two miles (3000 m.) of endless chain haulage. 
 
 The greatest difference of level between the highest point at 
 the Sol mine and the terminus at the station of Cadegal is 802 
 feet (244-60 m.), and on one part of the line the gradient is as 
 high as 29'5 per 100 or i in 3*4. The fall is so great that the 
 chain requires no power but gravity to work it ; in fact, it is 
 necessary to use brakes to oppose the vis viva. Strap-brakes are 
 employed in the same manner as they are on the inclines just 
 described, solely for the purpose of stopping the chain. The danger 
 of depending entirely upon such brakes for working inclines has 
 already been pointed out, and a uniform speed is maintained by 
 affixing fan-regulators working in water. They are chosen in this 
 case in preference to the fans working in air, because the latter 
 must revolve at a great velocity in order to be efficient, and there- 
 fore could not be applied to the slow chain haulage without gearing, 
 which would introduce complications. These hydraulic governors 
 are like the air-regulators in principle, except that the blades are 
 immersed in water ; the speed of the chain can be adjusted with 
 the greatest nicety by altering the quantity of water in the tank 
 in which the blades work, and so introducing the amount of 
 resistance required. 
 
 The usual speed at which the chain is run is 5 feet (1-5 m.) per 
 second, but it can be raised to 6 feet 6 inches. The chain is made 
 of |-inch (22 mm.) iron, which corresponds to about 19^ Ibs. per 
 
 * Jfapotftion Vnicerselle de iSSg. Op.cit., p. 15. 
 
380 ORE AND STONE-MINING. 
 
 yard (9-826 kil. per metre). The last section, however, has harder 
 work, and the chain is of i-inch iron (26 mm.) and weighs 28 
 Ibs. per yard (14 kil. per metre). Each waggon holds iyf cwt. 
 (900 kil.) of ore, and when the waggons are arranged 27 yards 
 (25*2 m.) apart, the chain haulage is capable of transporting 2500 
 to 2600 tons of ore a day, in addition to a certain amount of 
 rubbish which is tipped before arriving at the port. 
 
 6. Conveyance of Mineral by Boats from one part of a 
 mine to another is exceptional ; but transport by canal or sea 
 to the consumer is common, and is chosen whenever available 
 on account of its comparative cheapness. It is of the utmost 
 importance when dealing with large quantities of mineral to have 
 cheap and rapid methods of shipping it. At Huelva, the shipping 
 port of the Rio Tinto mines, the trains of ore are drawn on 
 to a part of the pier which has just enough inclination to make 
 a truck run down of itself. A workman then uncouples a 
 truck and allows it to run opposite a shoot, which leads to the 
 hold of the vessel lying alongside the pier. The truck is emptied 
 by opening the bottom and letting the contents drop into the 
 mouth of the shoot. The bottom is then closed and the truck is 
 allowed to run on a little further, when it is shunted back on to 
 a side line, and made to join the train of empties ready to be 
 drawn back to the mine. After the locomotive has once hauled a 
 train on to the proper part of the pier, the discharge of its 
 contents into the ship proceeds very rapidly and requires the 
 attendance of only one man. 
 
 The arrangements are so perfect that 500 tons can easily be 
 loaded in an hour, but naturally a good deal of time is lost in 
 shifting the steamers and berthing them. The greatest amount of 
 work in loading at Huelva pier has been a little over 3000 tons 
 in a single day. A steamer has been known to come into Huelva 
 harbour by one tide, and leave by the next with a cargo of 1500 
 tons of ore. 
 
 The Somorrostro Company loads its iron ore at Bilbao in a 
 similar manner. The Company has three wharves, at each of 
 which 2000 tons can be shipped in a day ; indeed a ship of 1490 
 tons has been loaded in six hours. 
 
 7. Aerial Ropeways. These ropeways may be divided into 
 five classes : 
 
 a. Single supporting rope, with or without a hauling rope. 
 
 b. Endless rope, which is the supporting rope and hauling rope 
 
 at the same time. 
 
 c. Two supporting ropes and an endless rope for hauling the load. 
 
 d. Double endless travelling rope or cnain. 
 
 e. Telpherage line. 
 
 a. Lines erected on the first of these principles may be seen in 
 hilly countries. An iron or steel wire rope is stretched across a 
 valley, and forms the rail supporting the load, which is put into 
 
HAULAGE OR TRANSPORT. 381 
 
 a sack and hung on by a grooved pulley. If the heights of the 
 departure and receiving stations are properly arranged, the load 
 on going down the slope acquires enough momentum to bring it 
 up to the station on the other side, without rushing in too 
 violently. The objection to this system is that the sacks and the 
 pulleys have to be carried back by men or women, but it has the 
 merit of simplicity and cheapness. By the addition of a small 
 hauling rope on a drum, the method is available for steep moun- 
 tain sides ; the load is lowered with use of the brake, and the drum 
 is worked to draw up the empties along the supporting rope. 
 
 b. In this system there is an endless rope, supported by pulleys 
 on strong wooden or iron posts placed at suitable intervals, which 
 is set in motion by any available source of power. Suspended from 
 the rope are the buckets or other vessels in which the mineral is 
 carried. The buckets may be detachable at pleasure or they may be 
 fixed. The former plan is the one brought out by Hodgson in 1 869. 
 The bucket or other receptacle is suspended by an iron hanger 
 from a grooved block of wood which rests upon the rope. The 
 carrying block has a spindle with a small grooved pulley, which 
 can be made to run upon a rail at each terminus and so let the 
 rope move on without the load. The bucket is filled from a shoot 
 or hopper while hanging on the rail at the loading terminus. A 
 workman then pushes it along the rail until the carrying block 
 is taken up by the rope, which is always in motion ; the load now 
 travels along suspended from the rope, the carriers being con- 
 structed so as to pass over the pulleys. On reaching the unload- 
 ing terminus, the carrying block is again shunted on to a rail, and 
 the bucket is tipped by lifting up the catch which had kept it from 
 turning about pivots ; after having been put into position, it is 
 brought round to the point where the rope, after passing round a 
 terminal pulley, is about to begin its journey back to the loading 
 station. Here it is shunted on to the rope and travels along 
 with it. 
 
 One great disadvantage of this system, in the case of steep in- 
 clines, is that the carriers may slip upon the rope, and that the 
 loads either fall off or do damage in some other way. To over- 
 come this difficulty, some of the constructors of aerial ropeways 
 attach the loads to a clip which is tightly fixed to the rope. The 
 clip must be of such a nature that it will pass the supporting 
 sheaves or pulleys. When the inclination is sufficient, an aerial 
 line of this description will work automatically, the weight of the 
 full loads being enough to draw up the empties. 
 
 c. The third system has two fixed ropes, which serve as aerial 
 rails and act solely as supports, and an endless travelling rope, 
 to which the loads are made fast at pleasure. It resembles, 
 therefore, the endless rope haulage, of which mention has been 
 made for underground work, save that the rails are above the 
 load instead of being below it. 
 
332 
 
 ORE AND STONE-MINING. 
 
 FIG. 423. 
 
 Ropeways working upon this plan have been perfected of late- 
 years by Otto and by Bleichert in Germany, where they are 
 commoner than in this country. They are constructed for distances 
 of from 2 to 8 or even 10 miles, with a carrying capacity of 600 to 
 800 tons per day of 10 hours. The separate loads may vary from 
 \ cwt. to i ton each. 
 
 The points to be considered are : 
 
 Carrying rope and vessel. 
 
 Posts or standards. 
 
 Hauling rope and attachments. 
 
 Terminals and their shunting arrangements. 
 
 The kind of cable used on the most recent lines erected on the 
 Otto system* is that known as "locked coil wire rope," the con- 
 struction of which is explained in the next chapter (Fig. 45 1). It 
 has the advantage of presenting a perfectly smooth surface, ad- 
 mirably adapted for the running of the grooved pulleys by which 
 the load is suspended. The vessel in which the mineral is conveyed 
 may be any convenient form of bucket 
 or box, supported by pivots around 
 which it can be easily tipped, or the 
 actual mine-waggons may be slung up 
 and the ore carried in them. 
 
 Each box, bucket, or waggon, is at- 
 tached to a hanger suspended from a 
 spindle placed midway between two 
 grooved pulleys or wheels, which rest 
 on the rope (Mg. 423). 
 
 The posts or standards are constructed 
 of wood or iron, sometimes with two, 
 and sometimes with four legs, suitably 
 stiffened by braces and held in position 
 by guy ropes or rods (Figs. 424 and 425). 
 The four-legged standards are used for 
 heavy loads or long spans. The distance 
 between the standards varies according 
 to the nature of the country, and is often 
 about 30 to 60 yards ; but where the 
 country is much broken by ravines, these short spans are unat- 
 tainable without standards of an impracticable height, and the 
 cable is the a made to stretch across very long intervals without 
 intermediate supports. Spans of 550 yards (500 m.) are not 
 unknown. 
 
 The hauling rope must be very flexible, and is made of fine steel 
 wire with a hempen core. The mode of attachment of the load 
 varies with the gradient of the line. If the gradient is less than 
 
 * J. Pohlig, " Aerial Ropeways, Otto System." Tram. Amer.Inst. M.E., 
 vol. xiy. 1891, p. 760. 
 
HAULAGE OR TRANSPORT. 
 
 333 
 
 i in 6, the amount of friction necessary for gripping the rope 
 tightly can be obtained by bringing it between two flat iron 
 discs and clamping them together with a screw. One of these 
 discs is rigidly attached to the hanger, and the tightening screw 
 of the other can be loosened automatically by providing it with 
 a projecting lever, which conies in contact with a stop at the 
 terminus. 
 
 If the gradient is between i in 6 and i in 3, the discs are made 
 
 FIG. 424. 
 
 FIG. 425. 
 
 with corrugated instead of smooth surfaces. When the gradient 
 exceeds i in 3, another device has to be employed ; projecting 
 knobs are inserted into the rope at regular intervals, and on 
 meeting with properly arranged stops upon the loads they cause 
 them to travel along. Figs. 426, 427 and 428 show the details 
 of the arrangement. 
 
 Each terminus is provided with an iron rail which is fixed 
 so as to meet the rope where the buckets have to be 
 loaded or unloaded ; by suitably arranging the end of the 
 rail, the load passes quite smoothly from it to the rope and vice 
 versd. 
 
384 ORE AND STONE-MJMNG. 
 
 An example of one of the Otto ropeways is given in Fig. 429, 
 which is a section of the line put up for the Sheba Gold Mining 
 FIG. 426. 
 
 Company, Limited, Barberton ; it is 2\ (4-4 kil.) miles long, and 
 will carry 150 tons per day of 10 hours. The maximum incline 
 is i in i '6, and the greatest span 1480 feet (451 m.). 
 
 FIG. 429. 
 
 VERTICAL SCALE 
 
 100 M O 100 200 300 400 5OO METRES 
 
 HORIZONTAL SCALE. 
 
 A line erected in Southern Spain for carrying iron ore is 9-69 
 miles (15*6 kil.), long, divided into four independent sections. 
 The greatest span is 918 feet (280 m.), but on an average the sup- 
 
HAULAGE OR TRANSPORT. 
 
 385 
 
 porting posts are only 44 yards (40 m.) apart. The hauling rope 
 is made to travel at the rate of 100 yards (90 m.) a minute, 
 and deliver two buckets, each containing 7 cwt. (350 kil.) in that 
 time. This means a carrying capacity of 1200 buckets or 420 
 tons per day of 10 hours. The line has also been worked with 
 
 two shifts of 8 hours each, and has transported 900 tons in that 
 time. The total cost of this line, which was surveyed, erected 
 in a very difficult country, and ready to start in ten months, 
 was ,26,000 ; and it has been worked at a cost of is. $d. per ton, 
 which includes all that is spent for labour, maintenance and 
 repairs. 
 
 At the Menzel colliery in Upper Silesia, 500 to 700 tons of 
 coal are carried in ten hours a distance of 1*6 miles, for i\d. per 
 
 2 B 
 
3 SS ORE AND STONE-MINING. 
 
 ton per mile, including wages, repairs, interest on capital and 
 depreciation of plant. Fig. 430 shows part of the line at Gottes- 
 segen colliery, Upper Silesia.* 
 
 A line carrying iron ore in Luxembourg is 3 miles long, and 
 transports 300 tons of iron ore in 10 hours at a cost, again in- 
 cluding all expenses viz., wages, repairs, interest on capital, and 
 depreciation of plant, of 4^d. per ton, or i^d. per ton per mile. 
 
 d and e. Ropeways worked by these systems are rare. 
 
 * "Otto Patent Ropeway." The Engineer, vol. Ixvii. 1889, p. 115. 
 
CHAPTER VIII. 
 HOISTING OK WINDING. 
 
 Motors, drums, and pulley-frames. Hopes, chains, and attachments. 
 Kibbles, skips, and cages. Keps, guides, signals. Safety appliances, 
 detaching-hooks, safety-catches, automatic stopping gear Pneumatic 
 hoisting. 
 
 BY hoisting is meant raising the minerals from the underground 
 workings to the surface. In speaking of the subject generally, 
 it is more correct to say hoisting than winding, because this 
 latter term implies the use of the rope, which is not quite 
 universal. As already explained in the last chapter, there is no 
 clear line of demarcation between haulage and winding. In 
 the typical case of a vertical shaft and a nearly horizontal level, 
 it is easy to make the distinction ; but when the mineral is 
 drawn up through inclines, the name given to the process 
 depends upon local custom. Thus, part of the shaft at a Cornish 
 tin mine is inclined at an angle of only 15^ from the horizontal, 
 and nevertheless the work of drawing up the ore is always called 
 winding. 
 
 In a few districts carriage on the back still survives; in 
 Sicily, for instance, much of the sulphur rock is brought to 
 the surface by boys on their backs up rough paths, or steps 
 cut in the ground. As lately as ten years ago, I found slate 
 being brought up on the back in the Moselle district. In 
 Mexico and in China, too, the same method is pursued in 
 some silver and other mines. However, this barbarous mode 
 of raising mineral is simply mentioned for the purpose of con- 
 demning it. 
 
 The regular method of bringing a mineral to the surface is to 
 draw it up a shaft or an incline by means of a rope. The subject 
 is such a wide one that it must be treated under different headings 
 as follows: (i) Motors, drums and pulley-frames; (2) Rope, 
 or chain ; attachments of the rope ; (3) Receptacle for the mineral 
 or waste rock ; (4) Other indispensable appliances, guides, signals, 
 keps ; (5) Safety appliances. 
 
 i. MOTORS, DRUMS, AND PULLEY-FRAMES. 
 Motors As in other departments of mining, the motor employed 
 may be worked by animal power, or by an engine driven by 
 water, steam, compressed air, petroleum or electricity. 
 
3 88 ORE AND STONE-MINING. 
 
 (a) Animal Power. The simplest contrivance for winding is a 
 pulley supported by some suitable frame above the shaft ; a bucket 
 is attached to the end of a rope hanging down the shaft, whilst the 
 other end, passing over the pulley, is drawn by men or women : 
 they simply walk away from the shaft and haul up the bucket. 
 Oil wells are sunk in Burmah by this primitive method of 
 hoisting. 
 
 The usual method of applying human power is by a windlass. 
 This well-known appliance consists of a wooden cylinder, about 
 eight inches in diameter, provided with two iron handles and 
 supported by two upright posts which are suitably stayed. A 
 sliding bar, which can be drawn out either above or below the 
 cylinder, serves to hold one of the handles, when required. 
 
 In this country, the ordinary windlass is used for shallow 
 sinkings of twenty, thirty, or forty yards in depth, such as are 
 made in commencing work at a mine, or in effecting a communi- 
 cation between two levels ; but in countries where mining is 
 less advanced, and where labour is cheaper, the windlass may 
 form the sole means for hoisting from depths of a hundred and 
 even two hundred yards. Thus, for instance, at Boryslaw, in 
 Galicia, it is reckoned that six or seven thousand shafts have 
 been sunk during the last thirty years, for the purpose of working 
 ozokerite, to an average depth of one hundred yards, by human 
 labour ; four, five, and even six men and women may be seen 
 working the Boryslaw windlass. In the neighbouring country of 
 Roumania, oil wells are sunk in like manner. The windlass is used 
 either with one or two buckets ; in the latter case the labour 
 is lightened, for the weight of the empty bucket going down 
 balances the dead weight of the bucket coming up with a load of 
 rock. 
 
 As a rule too little attention is paid to the state of the axles 
 and bearings. Windlasses, like other machines, cannot be worked 
 with economy unless means are taken to prevent unnecessary 
 friction, which is sure to arise unless the axles and bearings 
 are kept perfectly true ; this fact should be specially borne in 
 mind when the mine-owner is employing expensive human 
 power. 
 
 The capstan is an unusual form of winding machine at mines ; 
 it differs from the windlass by having its cylinder vertical. As an 
 instance of its use, I may mention the little underground quarries 
 at Swanage in Dorsetshire, where blocks of stone are drawn 
 up inclines by means of capstans turned with bars, after the 
 manner of those used on board ship. 
 
 When a horse is employed in the place of men, the bucket, 
 attached to a rope passing over a pulley, is sometimes drawn up 
 by making the animal walk away from the shaft. The framework 
 and pulley constitute what is called a whipsiderry. 
 
 Animal power is usually applied by means of a machine called 
 
HOISTING OR WINDING. 389 
 
 a horse-whim. It may be looked upon as a gigantic capstan, 
 worked by horses, mules, or donkeys, It consists of an upright 
 axle, usually of timber, supported at the bottom by an iron pin 
 cr pivot, which works in a hole in a large stone, forming a primi- 
 tive foot-block. A horizontal beam, known as the driving beam, 
 is attached to the axle, and above it comes a hollow wooden 
 cylinder or drum, around which the rope is coiled, proper project- 
 ing horns or flanges being provided to prevent it from slipping 
 off. 
 
 The other end of the axle works in an iron socket, carried 
 by a great horizontal beam, known as the span-beam, which is 
 supported by two legs. In this country the horse-whim is not 
 roofed over, and it forms a prominent feature in many mining 
 districts; where the weather is more severe, a house becomes 
 necessary. The winding rope is coiled several times around the 
 drum, and both ends, after passing over pulleys, hang down the 
 shaft ; when the horse walks round, one bucket is raised and 
 the other lowered. 
 
 Before the introduction of steam, the horse-whim was a very 
 important means of winding ; and in countries where water- 
 power is lacking, coal dear, and fodder cheap, it still performs very 
 useful services. As many as six to eight horses may be harnessed 
 to a horse- whim for the purpose of working it. 
 
 (b) Water. I will now pass on to the engines worked by water, 
 steam, compressed air, petroleum, or electricity. 
 
 When the water-wheel is used for hoisting, it is necessary to 
 have means of reversing the motion, in order to raise or lower 
 the rope at pleasure. Two methods may be employed : A 
 double wheel with the buckets fixed in opposite directions ; a 
 single wheel provided with suitable gearing or belts. The double 
 wheel is frequently seen underground in Germany ; it has sluices 
 (hatches} which will turn the water on to either side, and there is 
 a brake for controlling the motion. The winding-drum is placed 
 on the shaft of the water-wheel, and according as the water is 
 turned on to the right-hand or to the left-hand side, the wheel 
 revolves one way or the other. 
 
 When gearing is employed, a bevel-wheel upon the shaft of the 
 water-wheel drives a pair of bevel-wheels, facing each other, which 
 run loose upon the shaft of the drum. By means of a suitable 
 clutch either of them can be brought into firm connection with 
 the drum-shaft, and so made to drive it in the required direc- 
 tion. 
 
 Fig. 431 shows the method adopted at Great West Van Mine 
 in Cardiganshire by Messrs. Urquhardt and Small. A, Girard 
 turbine ; B, belt driving the shaft of two pulleys C D ; E and F, 
 pulleys loose upon the shaft ; G, clutch ; H, handle working clutch ; 
 I, pinion driving spur-wheel on drum J J ; K, brake strap ; L, pin 
 connected, when required, to "bob " of pumps. The belt from C 
 
39 
 
 OllE AND STONE-MINING. 
 
 FIG. 431. 
 
 to E is straight, and that from D to F is crossed ; therefore the 
 two pulleys E and F are always revolving in opposite directions. 
 According as E or F is made fast to the shaft by the clutch G, 
 the pinion I turns the drum one way or the other. 
 
 (c) Steam. Steam-engines em- 
 ployed for winding have usually 
 two cylinders, either vertical or 
 horizontal; the latter are preferred. 
 In some mining districts, notably 
 in Cornwall, one finds a single 
 vertical cylinder working a beam 
 by which motion is communicated 
 to a fly-wheel; but for rapid work 
 it is necessary to have more com- 
 mand of the engine than can be 
 furnished by a machine of this 
 kind. 
 
 It was the fashion at one time 
 to put a pinion upon the crank- 
 shaft and a spur-wheel upon the 
 drum shaft ; nowadays for quick 
 winding the drum is placed upon 
 the same shaft as the cranks. This 
 is called working on the first motion, 
 whereas if gearing is used the 
 method is said to be on the second 
 motion. In any case the engine 
 must be provided with an adequate 
 brake, and where the drum is 
 worked by gearing, it is necessary 
 to have a brake upon the drum 
 shaft, because otherwise there 
 would be no means of arresting 
 the descent of the load in case of 
 fracture of some of the cogs. 
 Although many winding engines 
 work without expansion, automatic 
 expansion gear is common, and 
 some of the engines are arranged 
 so that the commencement and end 
 of the run shall be worked with 
 the full power of the steam, and the middle of the run expan- 
 sively. Compound engines, and indeed triple expansion engines, 
 have been erected for winding purposes, though the advisability 
 of employing them is questioned by some mining engineers; 
 while fully admitting the value of this principle in the case of 
 engines which are working constantly, such as those used for 
 pumping, they contend that it is not advisable to complicate 
 
HOISTING OR WINDING. 
 
 FIG. 433. 
 
 machinery which is performing very irregular work, and is being 
 continually stopped and started. 
 
 Compound engines have, however, besn adopted recently for 
 winding at Llanbradach Colliery, near Cardiff, by Mr. Galloway. 
 The two cylinders on each side are arranged tandem fashion 
 (Figs. 432 and 433). A, high pressure cylinder; B, low pressure 
 cylinder; C, drum. 
 
 (d) Compressed Air. Compressed air is largely employed when 
 the hoisting engine has to be placed underground, and it is 
 especially suitable for 
 
 sinking intermediate FlG - 43 2 - 
 
 shafts (winzes). Com- 
 pact and handy forms 
 of engines are supplied 
 by various makers ; 
 many of them are 
 similar to the steam 
 winches used on board 
 ship, and consist of 
 two cylinders driving 
 a pinion which works 
 a spur - wheel placed 
 upon the same shaft as 
 the drum. 
 
 Occasionally, as for 
 instance at the Long 
 Tunnel, Walhalla, in 
 Victoria, all the hoist- 
 ing of a mine is done 
 
 by a compressed air 
 
 engine. The reason for this choice at the Long Tunnel was the 
 fact that lode was reached by a long adit, in which compressed 
 air appeared to be the most convenient method of transmitting 
 power from a motor at the surface. 
 
 (e) Electricity. Winding by electricity is as yet in its in- 
 fancy; but, no doubt, in the course of a few years, we shall 
 hear more of this convenient method of conveying power to the 
 place where it is to be used. It is easy to understand that an 
 electrical motor can be applied to the drum used for winding, 
 its rapid motion being reduced to a suitable speed by means of 
 gearing. 
 
 Drums. A winding drum is usually a mere revolving cylinder, 
 around which the rope coils itself. It is formed of two centre- 
 pieces keyed to the shaft, each carrying arms, to which are 
 attached rings. Supported by these rings are pieces of plank 
 or plates of iron or steel, which build up a hollow cylinder, the 
 length and diameter of which depend upon the importance of the 
 plant. In large mines one may see drums 20 and even 30 feet in 
 
392 
 
 ORE AND STONE MINING. 
 
 diameter ; with a drum of 20 feet, 10 revolutions mean coiling or 
 uncoiling 209 yards of rope. 
 
 A drum constructed for Llanbradach Colliery is a hollow- 
 cylinder 17 feet in diameter, and 8 feet wide. In Figs. 434 and 
 435, A is a cast-iron centre-piece ; B B are arms made of H -steel, 
 to which are riveted the crossbars of channel-iron C. The skeleton 
 formed in this way is covered with plates of steel D, J inch thick, 
 which are fixed with countersunk rivets to T~i ron E, where they 
 meet. F is the flange to prevent the rope from slipping off the 
 drum, and G the wrought-iron ring upon which the brake 
 acts. A novelty introduced by Mr. Galloway is the arrange- 
 ment for keeping a reserve length of rope to supply the loss 
 
 FIG. 434. 
 
 FIG. 435. 
 
 caused by successive re-cappings. Inside the main drum is the 
 hollow cast-iron cylinder H, capable of turning independently. 
 When a new rope is put on, 50 yards of it are coiled upon 
 H, the bolts of the clip I are fastened, and the remainder 
 is wound round the main drum. After re-capping the rope 
 at the end of two months, it is easy to unloose the clip and 
 draw out what is required. The drum is constructed as light as 
 possible, in order to prevent power from being wasted in starting 
 and stopping an unnecessarily heavy mass. The shaft is 20 feet 
 in diameter and 550 yards deep to the first seam of coal intended 
 to be worked ; but it will be probably made 600 to 630 yards deep 
 in time. The engine (Fig. 432) is expected to raise 200 tons of 
 coal per hour with two mine waggons in each cage, each waggon 
 carrying 2 tons. 
 
 An objection urged against the plain cylindrical drum is that 
 it in no way compensates for the change of work required of the 
 
HOISTING OR WINDING. 393 
 
 engine during the different phases of the act of winding. To make 
 this plain, suppose one end of the rope to be at the bottom of the 
 shaft with the full load attached to it, whilst the other end is at 
 the top with nothing but an empty cage. On starting, the engine 
 has to raise not only the weight of the load of mineral, but also 
 the entire weight of the rope hanging down the shaft, and in deep 
 mines with large cages, this weight is by no means inconsiderable. 
 In proportion as the full cage is raised, the amount of dead 
 weight of rope to be lifted becomes less and less. Eventually the 
 full and empty cages meet; the two portions of the rope then 
 balance each other, and the engine has simply to overcome the 
 action of gravity upon the mineral; later on the rope of the 
 empty cage is longer than that of the full one, and assists the 
 engine in doing its work. At last when the load is Hearing the top, 
 the drum is feeling the full weight of the rope of the empty cage. 
 
 Constancy of load is easily obtainable with the cylindrical drum 
 by the simple expedient of adding a balance rope that is to say, 
 a rope hanging down the shaft with one end attached to the 
 bottom of each cage. Provided that this rope agrees in weight 
 with the winding rope, the counterpoising is perfect, for on each 
 side, in every phase of the ascent or descant, there is always the 
 same dead weight acting upon the drum. This method is adopted 
 at Llanbradach and also at De Beers Mine. The balance rope 
 often, but not invariably, passes round a pulley at the bottom of 
 the shaft. 
 
 With the same object in view the drum is made spiral or 
 conical, or rather of a combination of two such drums united by 
 their larger bases. The rope is so arranged that the diameter of 
 the coil increases as the act of winding up proceeds. The load at 
 the bottom of the pit acts upon the drum shaft with a small 
 amount of leverage, and its leverage increases as the weight due 
 to the rope diminishes. The reverse condition of affairs exists 
 with the descending load : it has a large leverage while there is 
 only a short length of rope hanging down the shaft, but as the 
 weight thrown upon the drum increases, so the leverage 
 diminishes. 
 
 Intermediate between the conical and the cylindrical drum is 
 one which combines the two systems ; the conical end is used 
 for starting the load from the bottom and the main part of the 
 operation is performed with the cylindrical surface. 
 
 When a flat rope is used instead of a round one, it is convenient, 
 for the sake of distinction, to speak of the winding cylinder 
 as a reel or bobbin (Figs. 436 and 437).* It is provided on 
 both sides with long radial arms, which serve the same purpose 
 as the horns or flanges in the case of the drum ; that is to say, 
 they prevent the rope from slipping off sideways. 
 
 * Gallon, Lectures on Mining, vol. ii. plate Ixi 
 
394 
 
 ORE AND STONE-MINING. 
 
 The flat rope coils upon itself, and as the winding proceeds the 
 diameter of the coil increases, if the cage is being raised, or 
 decreases if the cage is being let down. In this way there is a 
 certain compensating action similar to that which is obtained 
 with a spiral drum in other words, at the moment of starting, 
 when the load is at the bottom, the smallest amount of leverage 
 is exerted upon the driving shaft of the reel ; whereas at the end 
 of the wind, when the load is least, it is exerting the greatest 
 leverage. 
 
 FIG. 436. 
 
 FIG. 437. 
 
 nt 
 
 SCALE 
 
 -ir 
 
 10 It 12. 13 K FT. 
 
 Pulley- Frames. The framework at the top of the shaft for 
 supporting the pulley or pulleys is known by different names. It 
 is sometimes called the head-gear, the pit-head frame, or poppet 
 heads (Cornwall). It may be constructed of timber, iron or steel, 
 and metal pulley -frames are usually seen nowadays at large mines, 
 where winding is conducted upon an extensive scale ; at small 
 mines and also during sinking operations a timber head-gear is 
 common. 
 
 A kind of frame often used is shown by Figs. 438, 439, 440, 
 from which it will be seen that four large upright posts support 
 cross-beams A, B, C, D, upon which the pulleys rest. The frame is 
 suitably stiffened by struts. Its principal duty is to resist two forces, 
 
HOISTING OR WINDING. 
 
 395 
 
 one exerted by the load and rope hanging down the shaft, and the 
 other by the rope which is being hauled in by the drum. At a 
 
 FIG. 439. 
 
 FIG. 438. 
 
 moment just before the load begins to move the two forces will be 
 equal, and the direction of their resultant will be a line bisecting 
 the angle between the two parts of the rope, and passing through 
 
 FIG. 440. 
 
 the centre of the pulley. Provision therefore should be made for 
 resisting this pull, and this is effected by stays, such as are shown 
 in Figs. 438 and 440, which represent a pulley-frame used for 
 
396 OHE AND STONE-MINING. 
 
 sinking a shaft some 200 yards deep at Halkyn Mine in Flint- 
 shire. The backstay may be placed in any position between 
 
 FIG. 441. 
 
 the bisectrix and a line parallel to the rope going to the 
 drum. 
 During the sinking at Halkyn only one bucket was used, and 
 
HOISTING OR WINDING. 
 
 397 
 
 as this had to hang in the middle of the shaft the pulley was 
 placed between the two beams B and C. Now, the shaft is used 
 for winding with two small cages and there are two pulleys, one 
 between A and B, the other between C and D. 
 
 Fig. 441 shows the head-gear erected at the perpendicular " Bock 
 shaft" of De Beers Mine,* whilst Fig. 442 represents the arrange- 
 ments at the Incline shaft of the same mine. 
 
 The head-gear at both shafts is made of wrought-iron trellis 
 work. At the Rock shaft the legs and stays are of 3 J-inch angle- 
 iron, | inch thick. The lattice bars are 3! by f inch ; the total 
 height from the ground to the centre of the pulleys is 61 feet. 
 
 FIG. 442. 
 
 Pulleys. Winding pulleys have to be placed on the pit-head 
 frame in order to change the direction of the rope. 
 
 Nowadays, in all important windings, the pulleys are made from 
 10 to 15, and even 20 feet in diameter, in order to subject the rope 
 as little as possible to sharp bendings, which would reduce its life. 
 
 The cast-iron boss, or centre, is joined by wrought-iron arms to 
 a grooved rim also made of cast iron (Fig. 443). In course of 
 time steel ropes wear away the rim, and to lessen this source of 
 trouble, the part in which the rope lies may be chilled. The 
 groove should fit the rope; for if it is too wide, the rope will 
 rest upon a small part of its circumference and be liable to be 
 squeezed. 
 
 At some mines pulleys are made with a light rim, which will 
 not last for more than a year. The object in view is the preven- 
 tion of wear from rubbing. When the speed of the engine is 
 
 * Second Annual Report of De Beers Consolidated Mines, Limited, for the 
 Tear ending March j>/, 1890, p. 16 and plates 10 and 7. 
 
398 ORE AND STONE-MINING. 
 
 slackening, the pulley, in virtue of its momentum, tends to travel 
 faster than the rope, and thereby to grind its surface. A dimi- 
 nution in the weight of the rim lessens the momentum, and 
 therefore reduces the rubbing action. The advantage gained in 
 this way, is considered sufficient to compensate for the more 
 frequent changing of the pulleys. 
 
 2. ROPES, CHAINS, AND ATTACHMENTS. Ropes. 
 Ropes are made of vegetable fibre of some kind, or of iron or 
 
 FIG. 443- 
 
 steel wire. The vegetable fibres used are hemp and manilla, 
 which are twisted into yarn ; the yarns are laid together so as 
 to form strands, and finally the strands are laid together to form 
 the rope. 
 
 For winding by hand, in sinking small intermediate shafts 
 (winzes), a hemp-rope, about | inch in diameter and made up of 
 three strands, is commonly employed. For heavier work, either 
 a round rope of larger section is necessary, or a flat rope formed 
 by sewing together several round ropes, 
 
 Iron is very little employed nowadays for making wire ropes, 
 its place has been taken by steel. 
 
HOISTING OR WINDING. 
 
 399 
 
 The advantage of using steel as compared with iron, is evident 
 from the following figures : * 
 
 
 5.g ^ 
 
 
 
 f 
 
 ll. s 
 
 
 Kind of Wire. 
 
 Saa 
 
 i*| 
 
 Kind of 
 Hope. 
 
 Total useful effect 
 in kilogram metres. 
 
 o"5 
 II 
 
 lilt 
 
 Remarks. 
 
 
 3*5 
 
 
 
 
 
 
 
 IP 
 
 
 
 3 
 
 Q 
 
 I? s 
 
 
 
 
 
 
 
 Kreuzfr. 
 
 
 Iron . 
 
 60 
 
 Cylindrical 
 
 5,387,124,051 
 
 5'5 
 
 0-817 
 
 
 Crucible | 
 Cast Steel j 
 
 120 
 
 ,, 
 
 26,519,326,190 
 
 
 0-354 
 
 
 
 120 
 
 Tapering 
 
 56,797,296,369 
 
 26-1 
 
 0-198 
 
 
 M 
 
 I SO 
 
 
 
 69,898,974,017 
 
 20-8 
 
 0-238 
 
 Eope still 
 
 
 
 
 
 
 
 in use. 
 
 FIG. 44305. 
 
 It must be remarked that the data concerning the last rope 
 are incomplete, as it was still in use when the paper was written. 
 
 At Pribram,f where winding is carried on in perpendicular 
 shafts, one of which has attained the enormous depth of 3642 
 feet, the ordinary crucible cast-steel, with a tensile strength of 
 120 kilos per sq. mm., was used up to the year 1885 ; since then 
 they have employed wire of " patent crucible cast steel " or 
 " extra " or " special crucible cast steel," with a tensile strength 
 of 1 80 to 190 kilos per sq. mm. ; the results are most satisfactory, 
 and the ropes, after having been in use for two and a half years, 
 showed very little sign of wear, and not a single broken wire. The 
 former ropes, made of ordinary cast steel, lasted on an average 
 only 26 months. 
 
 Winding-ropes are usually made with six strands and a central 
 core of hemp, each strand being made up of 
 seven wires (Fig. 443^). The core is sometimes 
 made of wire ; for instance, if the rope has to 
 work in a very hot shaft, or if it is used for 
 haulage purposes with clips which require that 
 the diameter should remain constant. In or- 
 dinary ropes the "lay" of the strand is like 
 that of hemp ropes ; that is to say, the reverse 
 of the lay of the rope (Fig& 444 and 445). 
 Lang has improved the method of manufacture by making the 
 lay of the strand the same as the lay of the rope ; the wires 
 are less sharply bent, and present a longer wearing surface. 
 
 * Habermann, " Ueber die Drahtseilfabrikation in Pribram mitbesonderer 
 Kucksicht auf die Drahtseile fiir die Verticalf orderung. " Beilaye z. Oest- 
 Zeitschr. f. B.- u. H.- Wesen, 1891, p. 8. 
 
 t Habermann "Anwendung verjiingter Forderseile aus gewohnlichem 
 und aus Patent- oder Extra-Tiegelgussstahldraht bei den grossen Schacht- 
 tiefen des Pribramer Bergbaues." Oest. Zeitschr. f. B.- u. H.- Wesen, 
 vol. xxxviii. 1890, pp. 403, 415, 432. 
 
400 
 
 ORE AND STONE-MINING. 
 
 FlGS. 444 and 445. 
 
 FIGS. 446 and 447. 
 
 The result is, that whilst the wires of an ordinary rope wear 
 quickly on the crown of the bend and break (Fig. 445), Lang's 
 rope, with its greater wearing surface, has a much longer life. 
 Figs. 446 and 447 are taken from actual examples of Lang's 
 rope before and after use. 
 
 Haggie's patent Protector rope has a special covering destined 
 
 to take the wear. Each 
 strand has a wire 
 wound round it spir- 
 ally, which protects it 
 from rubbing, and 
 therefore a more flex- 
 ible wire can be used 
 than would be advis- 
 able with an unpro- 
 tected rope. Whilst an 
 ordinary rope is weak- 
 ened by the wear of 
 its wires, the strength 
 of the protected rope 
 does not suffer from 
 the gradual thinning 
 of the covering. 
 
 Messrs. Latch and 
 Batchelor have lately 
 introduced a " flattened 
 strand "rope (Figs. 448, 
 449, and 450^, The 
 object of the new 
 method of construction 
 is to obtain an outer 
 surface more nearly 
 cylindrical than that 
 of the ordinarv rope 
 (Fig. 443)- T1 )e 
 strands are oval in 
 section, and this form 
 is produced by "lay- 
 ing " ordinary wires 
 round a flat wire or a 
 combination of wires. It is evident from the figures that the 
 bearing surface of the rope is thus increased, or, in other words, 
 that the liability of any individual wire to wear is lessened. It 
 is asserted by the inventors that their rope has 150 per cent, 
 greater wearing surface than Lang's or ordinary ropes. 
 
 In designing the " locked coil wire rope," now made by Messrs. 
 George Elliot & Co., the inventors departed entirely from the 
 old traditions of manufacture. They considered, and very properly, 
 
 FIG. 448. 
 
 FIG. 449. 
 
 FIG. 450. 
 
HOISTING OR WINDING. 401 
 
 that when one is dealing with a material like steel-wire, which 
 can be obtained of very great length, it is quite unnecessary to 
 copy the methods suitable for the short fibres of hemp. 
 
 These ropes are made of wires of different sections ; some of the 
 wires are V-shaped, others more like the letter S.and the adjacent 
 wires fit into one another like a set of spoons, the concave part 
 of one wire receiving the convex part of the next. The rope is 
 not composed of a series of strands, but of a series of concentric 
 rings of shaped wires, and the separate wires form long spirals. 
 
 By consulting Fig. 451, which represents one variety, it is 
 evident that nearly the whole of the section of the rope is made 
 up of useful material. There are scarcely any spaces such as 
 exist between the wires and the 
 strands of an ordinary rope, and Fio. 451. 
 
 consequently for any given section 
 the locked coil variety of rope is 
 stronger than a strand rope. 
 
 It is very flexible arid has a smooth 
 uniform surface, which makes it 
 look at a little distance like a solid 
 
 bar of iron. No one wire of the outer ring is more exposed to 
 wear than the other; consequently there is not the danger of 
 having broken wires, arising from the top of the crown being 
 rubbed off by continued use (Fig. 445). Another advantage is 
 the absence of any tendency to turn, whereas the ordinary rope 
 with the spiral strands twists somewhat when passing over a 
 pulley. In sinking a shaft with such a rope, the kibble spins 
 round during its descent and ascent, involving a risk of accident, 
 which is best avoided. However, strand ropes that will not twist 
 are supplied by some makers. 
 
 The disadvantage of the locked coil rope is that it cannot be 
 spliced, but sockets can be used for connecting one length to 
 another. 
 
 Intermediate in character between the ordinary rope and the 
 locked coil rope is the variety known as Laidler's patent " Sector 
 wire ropa." Each strand is cylindrical, and is composed of several 
 wires in the form of sectors of a circle, and the strands are laid 
 together to make the rope. Fathom for fathom, it is a little 
 heavier than Lang's rope, but it is said to give a great deal of 
 wear. 
 
 Chains. Chains were largely used in ore-mining at one 
 time. They have the advantage that they will coil round a 
 small drum, and the further advantage that they will stand much 
 rough usage, such as fell to their lot formerly in some of the 
 crooked shafts in Cornwall. But there is the overwhelming dis- 
 advantage that a chain is no stronger than its weakest link ; 
 and now that wire ropes have come into use in mines, winding 
 with the chain is practically a thing of the past. 
 
 2 c 
 
402 
 
 OHE AND STONE-MINING. 
 
 FIG. 452. 
 
 Attachments. It is important to study the modes of connect- 
 ing the rope to the receptacle by which the mineral 
 is drawn up. In sinking by hand in Cornwall, 
 the hemp rope is attached to the bucket by a knot 
 known as the " gooseneck," which is said never to 
 slip, and which is easily and quickly made; but 
 where the bucket is emptied without being de- 
 tached, this latter point is of little importance. 
 In Wales and the Isle of Man a spring hook 
 (clevis) is preferred, such as shown in Fig, 452, 
 the rope being put through an eye and made secure 
 by a large knot. This method i convenient when 
 it is necessary to detach the bucket, and move it 
 away from the shaft before it is emptied. A third 
 device is a spiral hook which will not allow the bucket to fall 
 
 off in the operations 
 
 FIG. 453. FIG. 455. FIG. 456. O f raising and lower- 
 
 ing, whereas it can 
 be readily taken off 
 by the workman. 
 
 With a wire rope- 
 it is necessary to form 
 a loop of some kind, 
 which can be attached 
 to the load by a D- 
 shaped link with a 
 screw pin. There are 
 several means of ef- 
 fecting this purpose. 
 The ropes sent from 
 the makers are often 
 supplied with an eye 
 spliced in (Pig. 453*)r 
 that is to say, the end 
 of the rope is turned 
 round an eye and 
 then spliced back so 
 as to hold it firm. As 
 there is not always 
 a competent splicer 
 at mines, methods of 
 attachment have to- 
 be employed which 
 
 _ ,__ are within the capa- 
 
 FIG. 454, c j y O f an or dinary 
 
 smith. Thus the end of the rope may be bent back over an eye 
 
 * Copied, by permission, from Messrs. George Cradock & Co.'s figures. 
 
HOISTING OR WINDING, 
 
 403 
 
 and held in position by three clamps (Figs. 454 and 455),* or a 
 socket may be riveted on (Fig. 456).* 
 
 Figs. 457, 458 and 459 represent a socket made by Messrs. 
 George Elliot & Co. for the locked coil rope and for ordinary round 
 wire ropes. A, locked coil wire rope ; B, socket ; C, hollow conical 
 plug ; D, wire bound or " served " round the rope ; E, ends of 
 the wires of the rope turned back over the cone ; F, wire bound 
 round them. After the end of the rope has been prepared in 
 
 FIG. 460. FIG. 461. 
 
 FIG. 457. FIG. 458. FIG. 459. 
 
 2 FEET 
 
 [METRE: 
 
 this way and drawn into the socket, the rings G G G are driven 
 down, and the fastening is complete. 
 
 Figs. 460 and 461 explain the "capping," which has been 
 adopted at some collieries near Bristol, since the failure of a 
 riveted socket. A A, clamps for holding the rope, each with 
 four bolts ; B, cast-iron plate with a groove all round it in 
 which the rope lies ; C, a large shackle attached to the iron plate 
 by a pin E. 
 
 A description of the method of splicing ropes will be found 
 
 * Copied, by permission, from Messrs. George Craddock & Co.'s figures. 
 
404 
 
 ORE AND STONE-MINING. 
 
 in the catalogues of some of the well-known rope-makers, and 
 need not be repeated here. 
 
 Splicing is not always adopted for joining two parts of a wire 
 rope ; sometimes a socket is attached to each end, and the two 
 sockets are then connected by a D-link with a screw pin. It 
 should be remarked that it is often at or near the socket that 
 the rope wears, and consequently it is advisable to remove the 
 sockets at regular intervals, cut oft* a piece of the rope, and 
 replace the socket where the rope is good and sound. 
 
 I have hitherto been speaking of winding ropes of uniform 
 section, but tapering ropes have advantages. Let us take the case 
 of a wire rope which is hanging down a deep pit. The part of the 
 rope at the bottom of the shaft has simply to support the cage 
 or bucket and the load contained therein, whilst the part at the 
 top must be strong enough to support not only the weight of the 
 receptacle and its laid, but also the weight of the rope below it. 
 In other words, greater strength is required at one end of the 
 rope than at the other, and on this account tapering ropes are 
 sometimes employed. 
 
 The advantage of employing such ropes is especially felt in 
 the case of very deep shafts, such as those of the famous lead 
 and silver mines of Pfibram already alluded to. Three of the 
 principal shafts have the following depths : 
 
 Kaiser Franz Josef shaft 
 
 Adalbert shaft 
 
 Maria 
 
 1000 metres or 3281 feet. 
 1070 3510 
 1 1 10 3642 
 
 FlG. 462. 
 
 The taper is produced by using successively wires of smaller 
 section, and not by reducing their number. 
 
 3. RECEPTACLES. There are three kinds of receptacles 
 in which the load is raised in the shaft : (a) Buckets (kibbles), 
 baskets or bags which are swinging loose in the 
 shaft ; (b) buckets or boxes (skips, Cornwall) 
 working between guides ; (c) cages carrying one 
 or more waggons. 
 
 (a) The buckets are made of wood, sheet 
 iron, or sheet steel. 
 
 Wooden kibbles are made of staves in the 
 same way as a barrel, and are suitably strength- 
 ened with bands of iron in order to resist the 
 wear. A petroleum barrel cut down at one end 
 may be easily converted into a kibble. 
 
 Various forms are seen viz., round, elliptical, 
 or square, and the sides are straight, or bulging 
 in the middle. Fig. 462 represents a common 
 form of sheet-iron kibble, made of hammered 
 plates riveted together and closed at the bottom by a circular 
 plate provided with a ring. At the top is the so-called bow, 
 
HOISTING OR WINDING. 405 
 
 either a bar of round iron with a hook at each end and bent 
 so as to form a loop in the middle, or else made thicker and 
 provided with a hole, to which the rope or chain is attached. 
 
 In perpendicular shafts, a lining of planks is often put in 
 around the winding compartment, so that the kibble may glide 
 up and down smoothly, without risk of catching against the 
 sides. 
 
 In inclined shafts the " footwall " side is lined with boards 
 (bed-planks) resting upon cross sleepers. Hard wood, such as oak 
 or beech, will naturally last longer, and require fewer repairs 
 than deal. In the Hartz, poles fixed lengthwise take the place 
 of boards, which are customary in this country. 
 
 Other receptacles used in winding are baskets, whence comes 
 the name corf(Jorb, German), bags made of hides used in Mexico, 
 small wooden platforms suspended by chains from the four corners, 
 and, lastly, nets, which are employed in Roumania. 
 
 A word must be said about the actual loading and emptying of 
 the kibble ; sometimes, as already mentioned, the kibble is filled 
 at the working- place or from a shoot (pass, Cornwall), and is then 
 conveyed on a trolley to the shaft, where it is hooked on to the 
 rope and drawn up. More frequently the filler, standing in an 
 enlarged part of the level (plat) where it joins the shaft, loads the 
 kibble with a shovel j in order to save time, two kibbles are 
 often provided, one being filled while the other is making the 
 journey to and from the surface. In this case it is necessary to 
 have some kind of clevis, which will enable the kibble to be readily 
 detached from the winding rope and quickly and securely fastened 
 oil again. 
 
 On the arrival of the kibble at the surface, the lander seizes 
 an eye or ring at the bottom (Fig 462) by a pair of tongs sus- 
 pended to a chain, and then gives the signal for the rope to be 
 lowered slightly. The kibble turns over because it is suspended 
 from the bottom, and its contents are shot out into a tram- waggon 
 placed ready to receive them. During the operation of discharg- 
 ing the kibble, the mouth of the shaft should be covered by a 
 hinged door, so as to prevent stones from falling down and 
 injuring the filler in the plat. 
 
 The inconveniences of this method of winding are considerable, 
 especially in inclined and crooked shafts. Rapid hoisting is out 
 of the question. Power is wasted in overcoming friction, and 
 there is great wear and tear of the bed-planks and casing boards ; 
 and, unless constant attention is paid to repairs, holes are worn in 
 which the kibble catches, causing the rope to break. The fall of a 
 kibble and its contents not only does much damage to the shaft, 
 but is also a source of danger to the men. In some old shafts the 
 friction must have been enormous, for deep grooves have been 
 worn in hard rock by the constant rubbing of the chain. 
 
 The aerial incline, known in Scotland as the " Blonclin," is a 
 
406 ORE AND STONE-MINING. 
 
 convenient method of raising stone from open quarries, when it 
 is necessary from time to time to alter the point at which load- 
 ing takes place. 
 
 A B (Fig. 463 *) is a strong upright post, held firmly in posi- 
 tion by guy ropes, of which only one, C A, is shown. A D is a 
 stout wire rope, fixed to the top of the post, and anchored at D 
 on the opposite side of the quarry. It constitutes an aerial rail 
 for two grooved pulleys contained in the travelling cradle E. 
 The rope F, attached to the cradle, passes over the large pulley 
 G, and thence to a horizontal winding-drum, not shown in the 
 figure. The engine-house is at the very edge of the quarry, and 
 is so placed that the engine-man can look down to the bottom. 
 The cradle E will run down from A to D by its own weight, and 
 can be drawn up by winding the rope F upon its drum. A loop 
 attached to E supports the large pulley H, and the hoisting rope 
 I. This rope passes under the pulley K, over the pulley H, over 
 a pulley immediately by the side of G, and thence to a drum 
 precisely like that of F, and running upon the same shaft. L is 
 a rectangular box, like the body of a waggon, which is loaded 
 with stone at the bottom of the quarry, and hooked on to the 
 four chains hanging from K ; it is then drawn up and landed on 
 to the truck M. I will suppose that the load has been hooked at 
 the point N in the bottom of the quarry, vertically below L in its 
 present position. The drum of I is thrown into gear by a clutch 
 and the rope wound up. K is gradually raised, and when it ap- 
 proaches H, the drum belonging to F is thrown into gear; the ropes 
 F and I are now wound up at the same speed, until E is drawn 
 close up to A, with its load hanging directly over M. Winding 
 is stopped, brakes are put on, and the drum of I is disengaged by 
 its clutch. By slackening the brake of I, while that of F is kept 
 tight, the load can be lowered on to M, which is trammed away 
 as required. An empty box is hooked on, K is wound up a little, 
 till it approaches H, and then, throwing the drum of I out of 
 gear, the engine-man lets both ropes run out under the control of 
 their brakes. When E has reached its proper position, it is 
 stopped by tightening the brake of the F drum ; K then descends 
 vertically till L has reached the bottom of the quarry. 
 
 It is evident that by properly arresting the descent of E, the box 
 can be lowered so as to pick up a load at any point along the line 
 O P, which is vertically below A D. If after a time it becomes 
 more convenient to load elsewhere, the anchorage at D is shifted 
 accordingly. 
 
 At slate quarries in North Wales and Cornwall, the rope F is 
 not used, and E is stopped by a clamp fastened at any desired 
 point of the rope A D. The arrangement shown in Fig. 463 
 introduced many years ago by Mr. Fyfe at granite quarries near 
 
 * For the sake of making a clear diagram on a small page, Fig. 463 is 
 not drawn to scale. 
 
HOISTING OR WINDING. 
 
 FIG. 463. 
 
 407 
 
4o8 
 
 ORE AND STONE-MINING. 
 
 Aberbeen, is better, for it does away with the necessity of 
 sending a man down the rope to adjust the clamp. A slightly 
 different plan is in use at Easdale slate quarry in Argyllshire. 
 The travelling cradle carries the usual hauling rope I, but in place 
 of P there is attached to it an endless rope, which stretches 
 across the quarry, and passes over suitable pulleys. So long as 
 the endless rope is free to move, the cradle will run from A to 
 D, but when the banksman stops its travel by a screw clamp, 
 the load ascends or descends vertically. ]f the slope of the 
 carrying rope fixed across the quarry is too small to allow the 
 cradle E to run of itself, an endless rope, worked by a drum, is 
 used for hauling it backwards or forwards as required. 
 
 (b) Guided Buckets or Boxes. When winding in shafts it is 
 best to employ guides, in order to keep the receptacle in one proper 
 c mrse, and prevent it from touching the sides. The guides may be 
 chains, wire ropes, bars of wood or round iron, or, lastly, iron or 
 steel rails. 
 
 Chains are rarely met with ; the commonest method of guiding in 
 perpendicular shafts is to hang two stout wire ropes from the top 
 to the bottom of the pit, and to provide the winding receptacle with 
 eyes which pass over them. They are kept taut by weights or screws. 
 Wire-rope guides may be used even in the case of a kibble ; a 
 cross-bar with two eyes is attached near the end of the winding 
 rope ; though the kibble remains loose, it is so close to the cross- 
 bar that it can swing but little. By fitting wire-rope guides of this 
 kind to perpendicular shafts originally worked with the ordinary 
 loose kibble, winding can be carried on 
 with greater speed and safety, whilst the 
 cost of making the alteration is com- 
 paratively small. There is the further 
 advantage that the shaft when provided 
 with guides becomes available for raising 
 and lowering the men. 
 
 Some years ago Mr. William Galloway* 
 introduced an ingenious method of apply- 
 ing these wire-rope guides to a shaft in 
 the course of sinking. He provides two 
 wire-rope guides coiled upon two drums 
 which are worked by a steam crane, 
 either separately or together. The guide 
 ropes (a a, Fig. 464) pass over two pulleys 
 at the top of the shaft, parallel to the 
 winding pulley, and are attached to a 
 platform, which serves as a walling stage, and is raised and 
 lowered as required. A hole in the middle affords a passage 
 for the bucket (kibble, bowk, hoppet). 
 
 * " Sinking Appliances at Llanbradach," Trans. South Wales Inst. oj 
 Enrj., vol. xvi., 1888, p. 113. 
 
 Fio. 464. 
 
HOISTING OR WINDING. 
 
 409 
 
 As the shaft is deepened, the guide ropes are paid out from 
 time to time, and in this manner it is only at the very bottom 
 that the bucket is swinging loose. The guiding apparatus consists 
 of a cross-bar having a round hole in the centre c, through which 
 the winding rope passes. It has two legs with holes, b 5, at top 
 and bottom which receive the guides. This rider descends as 
 the bucket is lowered, but when the legs meet with the walling 
 stage their motion is arrested ; the kibble, however, can proceed 
 further because the winding rope passes down through the central 
 hole c. 
 
 After passing below the stage the kibble is unguided, but the 
 distance it has to travel is rarely more than 15 or 20 yards. Before 
 starting on its upward journey, the kibble 
 is brought properly into line with the rope 
 and steadied, and on arriving at the stage, 
 
 an india-rubber buffer, carried by an iron 
 
 plate at the bottom of the rope, lifts up the 
 
 rider ; the remainder of the ascent is per- 
 formed without fear of the kibble swinging 
 
 or catching. 
 
 Mr. Galloway's latest walling stage has 
 
 two floors, 10 feet 6 inches apart ; the lower 
 
 one is a circular platform of timber fixed 
 
 to a frame of angle-iron d l <& (Figs. 465 and 
 
 466), and made to fit the inside of the shaft 
 
 as closely as possible. 
 
 The part h is hinged, and can be raised by 
 
 means of the chain, when passing the cross- 
 beams (buntons) which support a ventilating 
 
 pipe. The upper floor of the stage is similar 
 
 to the lower one, except that it is somewhat 
 
 smaller in diameter, and is not made to 
 
 cover the hinged segment below. The two 
 
 floors are held apart by four corner pieces 
 
 FIG. 466. 
 
 of angle-iron, to which are attached four plates of sheet iron, 
 forming together a frustrum of a pyramid, 5 feet 6 inches square 
 at the top, and 6 feet 6 inches square at the bottom. The object 
 of these plates is to prevent men who are standing upon the 
 lower stage from falling into the central opening, and at the same 
 time the upper floor constitutes a protecting roof over their 
 heads. 
 
 Men can climb from the lower to the upper platform by means 
 of the ladder m which passes through a small man-hole in the 
 iron covering plates. 
 
 The two guide ropes which carry the stage are shown by 
 letters n ri. 
 
 This double stage is decidedly safer than the single platform 
 
 on 
 
 ginally employed by Mr. Galloway. 
 
4 io ORE AND STONE-MINING. 
 
 Although primarily designed for sinking coal-pits, and most 
 frequently applied for this purpose, this method of guiding was used 
 with marked success in sinking a shaft at New Minera lead and 
 zinc mine near Wrexham ; it was found that the great advantage 
 of being able to wind with safety at a higher speed, fully repaid 
 the expense of putting in the guides. 
 
 In the Northwich mines, rock-salt is brought up in wooden 
 buckets guided much in the same way, except that round iron 
 bars are employed instead of ropes. Each length of rod has a 
 socket at one end and a projecting pin at the other ; the pin of 
 one rod fits into the socket of the next and is fastened by a 
 key driven through a slot. These guides are chosen in the special 
 case of salt because they suffer less from rusting than those made 
 of wire ropes, owing to the absence of interstices in which saline 
 water would collect and corrode the iron. 
 
 We next come to the box of rectangular or circular section 
 (skip), made of sheet iron or sheet steel. It usually has a sloping 
 bottom, and is provided with a hinged door for discharging its 
 contents; in some instances it is emptied by being turned over 
 automatically on reaching the top of the shaft. The skip may be 
 used in perpendicular, inclined, or crooked shafts. The guides or 
 conductors are most commonly rectangular bars of wood, bolted to 
 the end- pieces of the shaft and to the " dividings " in the manner 
 shown by Fig. 257. 
 
 If the shaft is perpendicular the skip may be guided by two 
 U-shaped shoes of iron, which clasp the three sides of the con- 
 ductor. If it is inclined the skip runs upon four wheels, as shown 
 by Fig. 467. In an inclined shaft the conductors sometimes have 
 rails, upon which the wheels of the skip run, in others the timber 
 is not protected in any way. Some of the skips in Cornwall are 
 made to hold as much as a ton and a half of tin-bearing rock. 
 
 When winding is going on from any particular level, a stop, 
 such as a strong bar of iron, is put across the shaft to arrest the 
 skip ; the miner, standing in the plat, shovels the mineral into it, 
 and gives the signal to have it drawn up as soon as it is filled. 
 
 A better plan is to adopt the arrangement explained in Fig. 467, 
 which will easily be understood. B is a strong plate working on 
 a pivot which is put down to stop the skip ; C is a pivoted hood 
 turned over the mouth of the skip so as to prevent stones from 
 falling into the shaft, and when this is in its place the workman 
 raises the door of a large bin or hopper, and allows part of its 
 contents to run out. The hopper has been filled by tipping 
 waggons from the line of rails in the level above. 
 
 On reaching the surface a hinged sloping door is turned over 
 the shaft, and the skip is lowered a little until it rests upon it ; the 
 workman (lander) then knocks up the bolt retaining the door of 
 the skip, arid the contents fall out into the tram-waggon placed 
 to receive them. The lander replaces the bolt, the skip is raised 
 
HOISTING OR WINDING. 
 
 411 
 
 slightly, the door pulled back, and the skip lowered once more 
 into the shaft. 
 
 The skip is sometimes tilted completely over instead of being 
 emptied through a hinged door ; this arrangement is in use in 
 some German mines, where the skip is made of wood and is guided 
 on each side by two pins or rollers running between two con- 
 
 FIG. 467. 
 
 
 due-tors. On reaching the surface, the two lower pins are sup- 
 ported and act as pivots, while the upper ones pass through 
 openings in the front guides ; the skip turns upon the lower pins, 
 is tipped over, and so emptied. 
 
 Some very rapid work is done at De Beers mine* with a self- 
 discharging skip, which shows that this method of hoisting must 
 not be despised, even by those who are accustomed to the wind- 
 ing of large quantities of coal from well equipped pits. 
 
 * Second Annual Report of De Beers Consolidated Mines, Limited, for the 
 year ended jsst March 1890, p. 14, plate 8. 
 
412 
 
 ORE AND STONE-MINING. 
 
 The skip (Figs. 468 and 469) runs upon four flanged wheels, and 
 the two upper or front wheels are half the width or tread of the 
 two back or lower ones. The winding rope is attached to two 
 chains, which are fixed to the cross-bar of a loop or stirrup which 
 can turn upon pins fixed to the sides. The skip runs upon steel 
 
 FIG. 468. 
 
 SCALE 
 
 9 FEET 
 
 2 METRES 
 
 rails (46J Ibs. to the yard) laid upon what may be called con- 
 ductors or longitudinal sleepers. At the bottom of the shaft 
 there is an iron shoot, without any door, leading to the skip. 
 During the descent of the skip, four end-tipping waggons are 
 brought into position round the shoot, the catches of the flap-doors 
 are loosened, and the doors held closed by two labourers. As soon 
 as it is seen to pass, the trucks are tipped, and the signal is given 
 
 FIG. 469. 
 
 to wind up. The skips are filled so quickly at the bottom, that 
 the man at the top sometimes receives this signal before he has 
 completely stopped his engine. 
 
 When the skip B (Fig. 442), ascending the incline shaft A, 
 reaches the point C, its rear wheels are caught up by a special 
 broad road D, the gauge of which is wide enough to let the front 
 wheels pass through. Whilst the front wheels are travelling on 
 the rails E, the rear wheels continue to mount, and consequently 
 the skip turns over and discharges its contents into the bin F. 
 
HOISTING OH WINDING 
 
 413 
 
 H is a waggon waiting to be filled, and G a counterpoise to the 
 discharge door. 
 
 On lowering the rope, the skip falls back into its original position 
 and descends the shaft. The inclination of the shaft is 56 20' 
 from the horizontal. The skip-ways are 5 feet wide and 4^ feet 
 high, and the gauge of the railway is 3 feet 1 1 inches. There are 
 two tracks, which converge at the bottom into one, so that both 
 skips can be filled from the same shoot. A skip holds 64 cubic 
 feet, or 4 loads, weighing in all 2 tons 17 cwt., or 2903 kilos. 
 
 The best single day's work, in two shifts of 10 to io| hours 
 each, was 6222 loads, or 4444 statute tons. The depth of the 
 
 FIG. 470. 
 
 FIG. 471. 
 
 fFeet 
 
 shaft is 840 feet along the incline, or 700 vertical ; the speed in 
 the shaft is 840 feet in 30 seconds, and the time occupied in 
 tipping and reversing about 6 seconds. This rate of working 
 has been carried on for an hour at a time, 5 skips being discharged 
 every three minutes that is to say, 285 statute tons per hour. 
 
 Fig. 470 shows the details of double-lipped mouth of the shoot 
 at the bottom of the great bin (F, Fig. 442), which receives the 
 blue ground brought up from underground. The door A is con- 
 trolled by the cam worked by the lever B, and the door C is upon 
 the same axis as the lever D. The discharge is thus easily 
 regulated, and waggons can be filled with great rapidity. 
 
 The arrangement for inclines shown in Figs. 471 and 472 
 differs slightly from that adopted at De Beers. A waggon A, 
 
4 T 4 
 
 OEE AND STONE-MINING. 
 
 running upon four wheels B, is drawn up by the bow F, and the 
 rope J. The bow is attached to the axles of the hind wheels, 
 
 FIG. 473- 
 
 and in front it carries the door I of the waggon. K repre- 
 sents the railway at the top of the incline, and P an additional 
 
 
HOISTING OR WINDING. 
 
 FIG. 474. 
 
 outer line of rails at a steeper angle. When the waggon in 
 its upward course reaches the point L, the rails P pick up the 
 small outer wheels C on the rear axle. These travel up at the 
 steeper angle whilst the front wheels follow the rails K. Conse- 
 quently, the waggon is tilted, and, as the front end or door is 
 attached to the bow, the contents are shot out. The stud G keeps 
 the waggon in position if it is 
 drawn up too far. On lowering 
 the rope, the waggon rights 
 itself and descends properly. 
 
 Automatic tipping, or dump- 
 ing, is also possible in per- 
 pendicular shafts. The' 'Hock" 
 shaft at De Beers is 20 feet by 
 6 feet, divided into four com- 
 partments which are each 4 
 feet 4 inches by 6 feet within 
 the timber : one for the pumps 
 and ladder-way, another for a 
 cage, and two for the skips. 
 
 Figs. 44 1, 47 3 and 474* repre- 
 sent the arrangements adopted. 
 A is the skip, a box of rect- 
 angular section, 5 feet by 3 
 feet at the top and 6 feet 
 deep; B, frame which clasps 
 the wooden guide on three 
 sides ; C, hinge by which the 
 skip is. attached to the frame; 
 D, hooked bar which catches 
 upon the pin E ; F, guide which 
 presses the little roller D 1 and 
 so unhooks the catch ; G, roller 
 which travels along the guide- 
 rails H for causing the tipping ; 
 I, nose upon the skip, which is 
 temporarily caught upon the 
 roller J during the tipping ; K, 
 inclined guide for the roller 
 
 G; L, crosspiece attached firmly to the side-frames B, with a 
 hole M, through which slides the strong square bar N; O, 
 toothed segments forming the safety catches ; P, plate attached 
 by chains to the axles of the catches ; Q, Ormerod's detaching 
 link ; R, shackle which is released ; S, rope-socket ; T, wire-rope ; 
 U (Figs. 441 and 475), bell-mouthed cylinder for causing the 
 
 13-0 
 
 * From drawings kindly supplied by the makers, The Grange Iron Co., 
 Limited, of Durham. 
 
4 i 6 ORE AND STONE-MINING. 
 
 detaching link to come into action; Y, chain-pulley of safety 
 catch ; W, strong spring, like a huge watch-spring. 
 
 After this explanation of the parts, the manner in which the 
 tipping or dumping is performed will be easily understood. As 
 long as the hook D is horizontal, the skip is prevented from 
 falling forwards, but on arriving at the top of the shaft, its 
 roller D 1 is drawn up against the guide F and the catch is released. 
 By this time the roller G has reached the guide-rails H, and 
 whilst the frame B follows a vertical path upwards, the box 
 itself, held back by G, turns upon the hinge C until it assumes 
 the position shown by the dotted lines, with the nose I resting 
 upon the roller J. As the frame ascends still further, the roller 
 G is drawn up along the inclined guide K, the bottom of the 
 box is tilted up, and its contents are discharged into the bin 
 or hopper. On lowering the rope the frame descends, the skip 
 drops back into its original normal position and is clamped 
 automatically by the bar D. 
 
 Whilst the plate P is held up against the cross-bar L, the 
 
 chains of the safety catches are drawn tight, and the teeth are 
 
 held clear of the wooden guides in the position shown. The 
 
 moment the rope breaks, the chains become slack, the springs 
 
 are then free to uncoil slightly and they force 
 
 FIG. 475. the teeth into the wooden guides. 
 
 If, instead of a breakage of the rope, there 
 is an overwind, the detaching link Q is drawn 
 into the bell-mouthed cylinder U (Fig. 475), 
 the lower part of the link is squeezed, as it is 
 too wide to pass through, and is thereby 
 caused to throw out projecting shoulders 
 which rest upon the top of U and hold up 
 the skip. By the same action the shackle 
 K is set free and goes with the rope over 
 the pulley. 
 
 A self-discharging skip, suitable for vertical, 
 
 inclined, or crooked shafts, is that of Messrs Kitto, Paul and 
 Nancarrow, used at Frongoch mine in Cardiganshire.* (Figs. 476 
 to 480). 
 
 The skip is the usual box A, made of sheet iron or sheet steel, 
 with four wheels B B, running on the vertical wooden conductors, 
 H H, and prevented from leaving them by the back guide D 
 (Figs. 477 and 479) at or near the bottom. 
 
 The bow or loop E, instead of being attached to the top of the 
 skip, reaches down, and takes hold of the axles of the bottom 
 wheels ; in its usual position (Fig. 478) it rests against the axles of 
 the upper wheels, and holds the skip upright. 
 
 * C. Le Neve Foster, "Some Mining Notes in 1887," Trans. Min. 
 and Imt. of Cornwall, vol. ii. p. 140. 
 
HOISTING OR WINDING. 
 
 At the surface, each of the two ordinary conductors bends 
 round and terminates in a horizontal piece, as shown in Fig. 480, 
 whilst a front guide H' is added on each side. 
 
 When the skip comes up, these front guides press upon the 
 top wheels, and turn them on to the flat ends of the ordinary 
 conductors. Deep grooves cut in the conductors at I enable the 
 back guide D to pass through, and as the rope continues to be drawn 
 up the bottom end of the skip is raised and its contents are tipped or 
 " dumped " into a large bin or pass, from which the ore can be 
 drawn away at pleasure. If the engine-man does not stop quite 
 soon enough, the skip is simply drawn up a little way, resting 
 upon the front guide, and the stop or stud F prevents it from 
 assuming a wrong position. 
 
 FIG. 476. Fir. 478. 
 
 FIG. 480. 
 
 FIG. 477. Fir. 47Q. 
 
 
 
 As soon as the engine-man begins to lower, the top wheels 
 fall upon the flat ends of the conductors, and, turning upon them, 
 the tail end of the skip drops, the back guide passes through 
 the slot I, and the skip, resuming its upright position, descends 
 the shaft. 
 
 The great advantage of this and other self -tipping arrange- 
 ments is the saving of time and labour. The time occupied in 
 lowering an ordinary skip on to the shaft-door, in knocking up a 
 bolt so as to discharge its contents, in closing it again, and in 
 raising the skip so that the shaft-door may be thrown back, is 
 all saved, and the services of the lander are dispensed with. 
 
 (c) Cage. The system of winding adopted almost universally 
 at collieries is that of using cages ; this method is likewise very 
 general in mining seams of ore, and is not uncommon in the case 
 of veins and masses. 
 
 2 u 
 
OllE AND STONE-MINING. 
 
 The cage, as its name implies, is a more or less open receptacle, 
 which receives the waggon used for underground transport, and 
 conveys it to the surface. 
 
 Figs. 481 and 482 represent the light and simple cage used in 
 the mines on the Comstock lode : * it is a mere timber platform 
 5 feet by 4 feet, resting on iron bars p and supported by iron rods 
 on each side. It is provided with a sheet-iron bonnet to protect 
 the men inside from anything falling down the shaft, and also 
 with safety catches, which come into play if the rope breaks. 
 
 FIG. 481. 
 
 FJC. 482. 
 
 The hand levers k k at the ends of the cage, raise up blocks 
 which keep the tram- waggon in its place during the ascent or 
 descent ; g g are the guides for the ends of the cross-bar b ; c, the bar 
 working the teeth it by levers ; f shoe or ear embracing the guide- 
 rod, or conductor, in the shaft ; r, the lifting bar ; s, a strong 
 spring which comes into operation if the rope breaks. 
 
 This kind of cage looks somewhat bare to European eyes, and 
 it is usual, on this side of the Atlantic, to make the sides less open 
 than shown in Fig. 482. 
 
 The dimensions of the cage are limited by the size of the shaft ; 
 but where it is desired to raise a larger quantity of mineral than 
 
 * J. H. Hagut?, "Mining Indnstry," Sep. U. S. Geol Expl of joth 
 Parallel, vol. iii., plate vii., p. 119. 
 
HOISTING OR WINDING. 419 
 
 can be contained in one waggon, or in two placed side by side, the 
 carrying capacity may be increased by constructing the cage with 
 two or more platforms, technically called decks. 
 
 As a rule, the full waggon is drawn out of the cage at the top 
 of the shaft, and is trammed to some convenient place wh ?re it is 
 tipped ; of late years the ingenuity of American inventors has led 
 them to introduce methods of tipping the waggon automatically 
 on reaching the surface, without its leaving the cage, in order to 
 save time in winding. Russell and Parson's automatic dump- 
 ing cage, said to be doing good work in the United States, has 
 its platform movable upon an axle underneath, which allows it to 
 be tilted on one side or the other. The cage has the usual shoes at 
 the top and bottom, which cover 5^ inches of the wooden guides 
 or conductors ; the tilting platform has its own two separate 
 shoes, which clasp only 2^- inches of the guides. Whilst the cage 
 is in the shaft, the platform is held in a horizontal position by its 
 shoes running upon the guides. At the surface the wooden con- 
 ductors are cut away for a depth of 2| inches, so that, although 
 the cage itself is guided, the small shoes are free to move side- 
 ways and permit the tilting, when the platform touches a properly 
 arranged stop. The flap-door of the waggon is released automati- 
 cally at the same time, and the mineral is shot out into a large 
 bin at the pit-top. 
 
 4. OTHER APPLIANCES Keps. On arriving at the 
 surface the cage is usually lifted a little higher than the landing 
 platform, and supports of some kind (keps) are brought under- 
 neath it, so as to hold it up while the full waggon is drawn off 
 and an empty waggon pushed on. The cage is then slightly 
 raised, the supports (keps) are drawn back by a lever, and the 
 descent begins. 
 
 Several methods of simplifying the work have been devised, 
 and among them is that of Messrs. Haniel and Lueg,* which has 
 been found to act satisfactorily at the well-known Mansfeld 
 copper mines. 
 
 The kep a, which is made of steel (Figs. 483 to 485), has an in- 
 clined face 6, and is provided with two slots, one horizontal and the 
 other d inclined. The former acts as a guide to the block e, 
 which is loose upon the axle f ; f is supported by the bearing g. 
 The pin i, surrounded by a steel roller A, can slide in the slot 
 d' } it connects the two levers k, one on each side of the kep 
 , which are keyed to the axle/. These are kept in a horizontal 
 position by a lever m provided with a spring catch. The steel 
 shoes 1 1, attached to the bottom of the frame of the cage, will, 
 if desired, rest upon the inclined faces b b of the keps. As long 
 as the lever m is held in the position shown in. Fig. 483, the keps 
 cannot open under the pressure of the load, because the pin i 
 prevents any motion in a horizontal direction. 
 
 * The explanation and figures are borrowed from their description, 
 
420 ORE AND STONE-MINING. 
 
 When the lever m is being drawn back, as shown by Fig. 484, 
 the pin i with its roller h is forced up the slot and the keps slide 
 back on the bed-plate of the bearing g, until the cage has room 
 enough to pass ; when it has gone down, the keps are returned to 
 
 their original position 
 (Fig. 483) by moving 
 the lever m forwards. 
 The ascending cage 
 opens the keps by 
 itself, for the shoes 
 1 1 turn them upwards 
 (Fig. 485), the lower 
 part of the slot d 
 being concentric to 
 the spindle /. As 
 soon as the cage has 
 passed, they fall back 
 into their normal posi- 
 tion (Fig. 483), and 
 the cage is lowered so 
 as to rest upon them. 
 The advantage 
 claimed for keps of 
 this kind are: Eco- 
 nomy of steam and 
 saving of time, besides 
 the increased duration 
 of the rope, which no 
 longer has to under- 
 go the strain of start- 
 ing the cage upwards 
 before it begins its 
 downward journey. 
 
 Signals. It is ne- 
 cessary to have some 
 means of communi- 
 cation between the various on-setting places and the top of the 
 shaft, so that the man at the bottom (on-setter, hooker-on) 
 may be able to inform the man at the top (banksman, lander, or 
 engine-man}, when he is ready for the cage, skip, or kibble to 
 be drawn up. 
 
 In shallow workings shouting is sufficient ; when the pit becomes 
 deeper a speaking-tube is sometimes put in, but the commonest 
 method of signalling is by a cord made of seven galvanised wires, 
 and varying in diameter from J to f inch. The object of the 
 zinc coating on the wire is of course to prevent or delay 
 rusting, which would otherwise go on rapidly in the damp 
 atmosphere of many shafts. 
 
. HOISTING OR WINDING. 421 
 
 The cord is carried round curves and corners by means of 
 cranks similar to those used for house-bells, only larger and 
 stronger, and when it is pulled by a lever at the bottom, it 
 moves a hammer which strikes a bell at the surface. Instead of a 
 bell, a loose plate of iron is sometimes used, which makes a very 
 audible signal ; the number of strokes indicates what is required. 
 The usual code is as follows : 
 
 1 stroke means " Stop." 
 
 2 strokes mean "Wind, up." 
 
 3 "Lower." 
 
 Various signals can be arranged to indicate when men are to be 
 drawn up in place of the ordinary load of mineral ; and sometimes 
 a visible signal is combined with an audible one, a hand upon a dial 
 recording the number of times the bell has been sounded. When 
 persons are raised and lowered, there must also be means of 
 signalling from the surface to the on-setting places ; the object 
 is to assure the men at the bottom that their signal has been 
 correctly received and understood. 
 
 Electricity can also be called to the aid of the miner, and electric 
 bells are common. Telephones * of various descriptions are some- 
 times used, but for the ordinary purposes of winding, the simple 
 signal given by a bell is quite sufficient. 
 
 In addition to the signal for starting and stopping, there is 
 an indicator which shows the engine-man the exact position of 
 the load in the shaft. 
 
 The indicator may be a dial with a hand, worked by gearing 
 connected with the crank-shaft of the winding-engine; the 
 various stopping places are denoted in the same way as the hours 
 on the face of a clock, the gearing being arranged so that the 
 hand does not travel more than the entire circumference during 
 the longest journey of the load. 
 
 Another form of indicator is an upright standard, 6 or 8 feet in 
 height, with a slot, in which a pointer moves up and down. It is 
 worked by a cord, or a steel band connected to the crank-shaft. 
 The standard has horizontal lines, numbered according to the 
 depths of the different stopping-places ; the gearing is contrived 
 so that when the finger points to one of these lines, the cage is at 
 the corresponding stopping-place. 
 
 The arrival of the load near the surface may be brought to 
 the engine-man's notice in several ways : by a mark on the rope, 
 by the pointer on the indicator, and by some audible signal, 
 worked automatically by the winding-engine. A travelling 
 hammer may be carried along by a bcrew, connected by gearing 
 
 * The first time the telephone was used for transmitting speech from 
 underground workings of a mine was in September 1877, when Mr. Arthur 
 Le Neve Foster made some experiments at West Wheal Eliza, in Corn- 
 wall. 
 
422 
 
 ORE AND STONE-MIXING. 
 
 with the crank-shaft, and eventually brought up against a bell ; 
 it works in the same manner as the device upon typewriters 
 which warns the operator that he is coming to the end of a line. 
 Instead of striking a bell, the traveller may open a cock and start 
 a steam whistle. 
 
 5. SAFETY APPLIANCES Overwinding In rapid 
 winding with large drums, a slight inadvertence on the part 
 of the engine-man may cause the load to be drawn up against 
 the pulley, and this is what is commonly known as over-winding. 
 In the case of a drum 18 feet in diameter, a single revolution 
 raises the rope 56^ feet; therefore, if even half a revolution is 
 allowed beyond the proper number, an accident will ensue, unless 
 the pulley frame gives a margin of nearly 30 feet. 
 
 Thsre are various contrivances for preventing disasters of this 
 
 FIG. 485. 
 
 FIG. 487. 
 
 kind ; one method consists in interposing between the rope and 
 the cage a special appliance, called a detaching hook, which will 
 sever the connection between them, allow the former to be 
 wound up, and at the same time hold up the latter safely without 
 damage to the load or persons inside. 
 
 Some well-known detaching hooks are those of King and 
 Humble, Walker, and Ormerod (Fig. 475)- 
 
 King and Humble's consists of an outer framework of two 
 cheeks or sides, containing two inner plates which can move about a 
 central bolt b (Fig. 486). Each plate has a wing a, projecting 
 beyond the framework. When in use the two plates are pre- 
 vented from coming apart by a small pin or rivet, c. 
 
 If the cage attached to e is wound beyond a certain height, 
 the detaching hook is drawn into a round hole in a strong 
 iron plate (Fig. . 487), and when the projecting wings, a , 
 strike against this plate, they are forced to move inwards, the 
 
HOISTING OR WINDING. 
 
 423 
 
 rivet is cut, the shackle d at the end of the rope is set free, and 
 two catches //are thrown out; these drop upon the plate and 
 hold the cage firmly suspended. 
 
 Walker's detaching and suspending hook is like a pair of 
 tongs, which hold the shackle at the end of the rope ; the legs 
 of the tongs are bent out, and if they are brought together the 
 tongs open. 
 
 FIG. 489. 
 
 FIG. 488. 
 
 In Figs. 488, 489 and 490, L is the end of the winding rope, 
 and A the shackle attached to it by the pin P. D D are the 
 two jaws of the tongs, and F F are projecting hooks. E is the 
 centre pin about which the jaws can move, and H an annular 
 clamp which prevents the jaws from opening, as long as it is 
 kept up by the two supporting pins I 1. The cage or skip is 
 hung on to the link B, and the weight of the load acting upon 
 the two legs of the tongs tends to bring them together and open 
 the jaws JD D, 
 
 When winding is going on properly, the jaws are kept together 
 
424 
 
 ORE AND STONE^MINTNG. 
 
 FIG. 490. 
 
 by the clamp, and the load remains firmly attached to the rope ; 
 but if it is raised too high the detaching hook enters the strong 
 ring C, through which it can pass freely until the flanges K K of 
 the clamp H strike against it. The pins I I are sheared off and 
 
 the clamp drops ; but as soon 
 as the hooks F F have passed 
 through the ring, the jaws 
 D D are drawn open by the 
 weight of the load, the shackle 
 is thus released and the 
 hooks catch on the top of 
 the ring C. As an addi- 
 tional precaution there is a 
 projecting rim at 0, to catch 
 the hooks if by some chance 
 they should fail to act at the 
 top. 
 
 Stopping Gear. The dis- 
 engaging appliances just de- 
 scribed are designed with a 
 view of correcting the effects 
 of an overwind, by preventing 
 the ascending cage from being 
 dashed against the pulley, 
 and then possibly falling 
 down the shaft. But they in 
 no way protect the descend- 
 ing cage from bumping on 
 the bottom ; even if they 
 did, the old motto still holds 
 good that " prevention is 
 better than cure," especially 
 as detaching hooks have been 
 known to fail. 
 
 Engineers have therefore 
 been anxious to obtain some 
 means of automatically stop- 
 ping the cage before it is 
 raised too far, and many 
 appliances for this purpose 
 have been invented. 
 Three which were exhibited at the Paris Exhibition of 1889 
 deserve special mention, as they are in regular use at large and 
 important mines viz,, the automatic speed-checkers and stopping- 
 gears of Reumaux, Villiers, and Wery.* M, Reumaux lays down 
 
 * Pamphlets issued by the Mining Companies at the Exhibition, and 
 Revue Universelle des Mines et de la Metallurgie. 3* Serie, vol, xix., 1892, 
 pp. 949-956, and plates* 
 
HOISTING OR WINDING. 425 
 
 the principle that too much confidence must not be placed in an 
 appliance which is only occasionally called into action ; and his self- 
 acting speed-checker comes into play at every wind. When the 
 cage in its ascent passes a point 30 m. below the surface, a tappet 
 upon the revolving indicator lifts a valve, and so puts one end of a 
 piston valve into communication with the atmosphere ; as steam 
 or compressed air is pressing upon the other end, the valve 
 moves and shuts off steam from the engine almost completely. 
 The same release of pressure causes another valve to rise and let 
 steam into the cylinder working the brake. If the engine-man, 
 after turning on steam again, is again inattentive and allows the 
 cage to be drawn up 2 feet above the landing, a second tappet upon 
 the indicator once more causes the steam to be shut off; and a 
 third tappet, by opening an exhaust passage, makes another valve 
 drop and turn steam on to the cylinder controlling the brake. 
 M. Reumaux's appliance is attached to all the winding machines 
 used at the extensive Lens collieries, whether they are worked 
 by steam or compressed air. 
 
 Yilliers' apparatus is somewhat complicated, and cannot be 
 properly understood without a figure. Suffice it to say that a 
 nut travelling upon a screw sets gearing in motion and so 
 actuates a friction clutch ; this brings into play a regulator which 
 opens a valve and lets out the compressed air from under a piston 
 holding up a weight. The weight in dropping shuts off steam 
 and puts on the brake. A second part of the apparatus, working 
 in a different manner, produces like effects ; and, lastly, if the cage 
 is wound up a certain distance above the landing, it strikes a 
 catch which releases another counterpoise, the descent of which 
 also causes the brake to act. 
 
 With Wery's contrivance the connection between the winding 
 drum and the checking apparatus is again effected by gearing 
 and levers instead of fluid pressure. When the cage has reached 
 a certain point near the surface, a nut travelling upon a 
 screw lifts a rod carrying a pawl, which rests upon the teeth 
 of a wheel turning round by clockwork. If the pawl rises more 
 quickly than the wheel revolves, it lifts it, and by means of 
 levers brings the steam-brake into action ; the speed of winding 
 is thus diminished. The clockwork is so regulated that the brake 
 is not made to act unless the speed is excessive. To prevent 
 danger from a slow overwind, a second rod acts in any case and 
 turns steam on to the brake cylinder if the cage is drawn up too 
 high. 
 
 Bertram* and Cobboldf have invented automatic stopping 
 appliances which depend upon the action of a ball governor, 
 
 * " On Overwinding and its Prevention," Trans. Fed. Inst.M.E., vol. i., 
 1890, p. 55. 
 
 t "A Patent Apparatus, Indicator and Valves for the Prevention of 
 Overwinding at Mines." Ibid., p. 61. 
 
426 OEE AND STONE-MINING. 
 
 connected by gearing with the main driving shaft of the winding 
 drum. 
 
 Paschke and Kastner's apparatus, used at many mines in the 
 Freiberg district, is spoken of favourably. It automatically 
 shuts off steam and puts on the brake, not only when the cage is 
 being drawn up too high, but also when the speed is excessive. 
 
 Safety Catches. Much ingenuity has been displayed by 
 various inventors during the last fifty years, with the object 
 of providing some form of catch which will come into play if the 
 rope breaks, grip the guides or conductors, and prevent the cage 
 or skip from falling down the shaft. 
 
 Many of them are actuated by a spring, and one form has 
 already been figured in describing the cage used on the Comstock 
 lode (Figs. 481 and 482). 
 
 While the load is hanging from the rope, the spring s s is 
 drawn into the position shown by the dotted lines by the lifting 
 bar r, the eye of which is figured in its two positions. The bar 
 c is drawn up at the same time, and the teeth 1 1 are held apart 
 and kept clear of the guide. If the rope breaks, the spring 
 forces down the bar b and with it c ; the teeth jam into the 
 wooden conductor, and the cage is arrested and held firmly. 
 
 The safety catch used for the De Beers skip (Fig. 473) 
 likewise depends upon the action of springs. 
 
 An objection often urged against safety catches is that they 
 occasionally come into play when not wanted, and that owing to 
 rust and disuse they get out of order, and sometimes fail to 
 act at the proper moment ; for these reasons they are less popular 
 on this side of the Channel than on the Continent. Many 
 engineers, rather than trust to contrivances which may possibly 
 fail under the conditions met with in mines, are more inclined to 
 put their faith in the following precautions : 
 
 1. Insuring an excellent quality of rope, by going to a maker of 
 
 good repute and paying a fair price. 
 
 2. Frequent minute examination of the rope. 
 
 3. Testing pieces of the rope at regular intervals. 
 
 4. Protection of the rope from the action of the atmosphere or 
 
 acidulous water in the mine by a suitable grease. 
 
 5. Cutting off the end of the rope where it is attached to the cage 
 
 and re-making the attachment at regular intervals. 
 
 6. Discarding the rope after it has been in use a certain fixed 
 
 time, even if it is apparently sound as far as outward exam- 
 ination can show. 
 
 The same feeling seems to have existed among the members of the 
 Royal Commission upon Accidents in Mines,* for they say, " We 
 have, however, examined several varieties of the safety cages in 
 
 * Fined Report. of .Her Majesty's Commissioners appointed to inquire into 
 Accidents in 31ines, p. 109. London, 1886. 
 
HOISTING OR WINDING 427 
 
 use, as well as those exhibited at successive International Exhibi- 
 tions, and we have considered a large number recently described 
 arid figured in an elaborate paper by Herr Selbach,* and we are 
 unable to come to the conclusion that any one of them is a trust- 
 worthy safeguard against accidents." This opinion does not settle 
 the question ; for, on the other hand, I may refer to the con- 
 clusions which Menzelf draws from the study of carefully pre- 
 pared official statistics. Though far from asserting that existing 
 safety catches are perfect, he shows that on the whole they did 
 useful work during the seven years 1884-1890 in the coal and ore 
 mines of Saxony, and he considers that they should be applied to 
 all cages used for winding men. 
 
 Springs. The rope suffers the greatest strain at the com- 
 mencement of the ascent of the cage. There is always a little slack 
 rope, which is taken up as the winding begins, and this leads to the 
 danger of a sudden strain being put upon the rope every time that 
 it begins to lift the cage, especially in cases where winding is being 
 carried on rapidly. In order to spare the rope from a shock of 
 this kind and cause it to take the weight gradually, a steel or 
 india-rubber spring may be interposed between the cage and the 
 rope, arranged in such a fashion that the first action of the pull 
 is merely to compress it; finally, when the compression has 
 reached a certain stage the cage will be lifted. The bearings of 
 winding pulleys are sometimes supported by springs with a 
 similar object in view. 
 
 Testing Ropes. The Commentry Fourchambault Mining 
 Company keep a useful record of the state of their winding ropes 
 by testing them at regular intervals. Once in every six months 
 a piece of rope about 9 feet long is cut off and sent to a powerful 
 testing machine, called the antheximeter, capable of breaking a 
 new wire rope more than 2 inches in diameter. The machine 
 registers upon paper not only the force required to break the rope, 
 but also its elongation previous to rupture. By comparing the 
 results obtained in this way, the gradual deterioration of the rope 
 from wear can be followed with great precision. J 
 
 In the mines of the Dortmund district, no winding-rope can be 
 used for raising and lowering men until it has been carefully 
 tested in a manner prescribed by the Government authorities. A 
 piece of the rope one metre in length is cut off, and the tensile 
 strength and the flexibility of each wire are determined, with 
 the exception of wires forming cores. 
 
 Pneumatic Hoisting. The most novel hoisting apparatus 
 
 * Zeitschr. fur das B.- II.- und S.-Wesen, vol. xxviii. 1880. B. AbJtand- 
 lunfjen, p. I. 
 
 t "Die in den Jahren 1884-1890, beim sachsischen Bergbau vorge- 
 kommenen Brtiche von Forderseilen, Schurzketten und dergleichen." 
 Jalirb.f. d. J3.- u. II.- Wesen i. K. Sachsen, 1891, p. 39. 
 
 jRcndus Mensuels, Soc. Ind. Min. 1891, p. 257. 
 
428 ORE AND STONE-MINING. 
 
 is that of M. Blanchet, which was regularly at work in the 
 Hottinguer shaft at Epinac in France for some years. M. 
 Blanchet fixed in the shaft a large pipe with a piston, from which 
 was suspended a cage carrying waggons. By exhausting the air 
 above the piston the load was gradually forced up by the atmo- 
 spheric pressure below it. The Hottinguer shaft is 660 yards 
 deep, and the pipe was 5 feet 3 inches in diameter, made up of 
 a succession of cylinders of sheet-iron about T \ inch thick and 
 4 feet 4 inches high, joined by flanges and bolts. The 485 rings 
 composing the long pipe weighed altogether 418 statue tons. The 
 cage had nine decks, and arrangements were made for unloading 
 three at a time ; each waggon held half a ton, so that the total 
 useful load was 4^ tons. The speed of hoisting was 20 feet per 
 second. If two hoisting pipes are connected, the dead weights 
 may be made to balance each other, and the power required is 
 simply thab which is necessary to overcome the weight of the 
 useful load. All the men preferred the pneumatic hoist to the 
 ordinary cage for descending and ascending the mine, and were 
 regularly lowered and raised by it. The advantages claimed by 
 M. Blanchet for this system are (i) the possibility of hoisting 
 from depths at which rope-winding would no longer be practicable ; 
 (2) getting rid of the costly ropes and dangers connected with 
 rope-winding; (3) better utilisation of the engine power; (4) 
 improvement of the ventilation and diminution of the amount of 
 fire-damp. At the present time Blanchet's apparatus is no longer 
 employed, but the disuse of the pneumatic method is in no way 
 due to any difficulty in making it work satisfactorily.* 
 
 * Nougarede, "Etude historiqne sur le puits Hottinguer des Mines 
 d'Epinac," Butt. Soc. 2nd. Min. 3 e Serie, vol. vii., 1893, p. 563. 
 
( 4*9 ) 
 
 CHAPTER IX. 
 
 DRAINAGE. 
 
 Surface drainage Dams Drainage tunnels Siphons Raising water by 
 winding machinery Pumps worked by engines at the surface 
 Rittinger pump Counterbalances Bochkoltz's regenerator Rossig- 
 neux's contrivance Catches Pumps worked by engines placed 
 below ground " Duty " " Slip " Co-operative pumping. 
 
 THE mineral having been raised to the surface, the task of the 
 miner might appear to be at an end ; but this is not the case, for 
 it is further necessary that he should keep his mine free from 
 water and foul air. These two indispensable operations of drain- 
 ing and ventilating require special appliances, which often add 
 considerably to the general cost of mining. 
 
 Surface Water. As far as possible the miner should endeavour 
 to prevent the entry of water both at the surface and under- 
 ground, and so escape the unnecessary expense of pumping it up. 
 In some instances a good deal can be done in this direction ; for it 
 has been abundantly proved, in many cases, that the bulk of the 
 water with which the miner is burdened is merely the result of 
 the percolation of the rain falling in the district. The effect 
 even of a prolonged rainfall is not usually felt at once, for it 
 takes time for the water to find its way through minute cracks 
 and crevices in the ground and reach the workings. In lime- 
 stone districts, however, the rain may find large channels eaten 
 out by atmospheric agencies, and affect mines at a depth of a 
 couple of hundred yards within twenty-four hours after it has 
 fallen. 
 
 It often happens that the mineral was quarried near the surface 
 before underground mining was resorted to, and in that case there 
 is always the danger of the old open pits forming a sink, so to 
 say, which will collect water from the neighbourhood and let a 
 considerable quantity percolate into the workings. To avoid 
 such an objectionable state of things, the surface must be drained ; 
 special care is imperative where the ground is cracked by sub- 
 sidences, and the neighbouring streams should be examined and 
 the water carried along in launders or other safer channels, if 
 their beds cannot be made stanch by filling the fissures with 
 concrete. 
 
43 
 
 OIIE AND STONE-MINING. 
 
 When working under the sea or a river, a rich lode must not 
 tempt the miner to carry on his work too far. At Wheal Cock, 
 near St. Just in Cornwall, the miners working in some overhand 
 stopes actually bored more than one hole through to the sea- 
 bottom. They were well aware of the proximity of the ocean, 
 for they could hear the boulders crashing against each other in 
 stormy weather, and they had wooden plugs ready, which they 
 drove into the holes when they actually tapped sea water. But 
 it was a dangerous experiment, and though in this case the rocks 
 are so hard and compact that the amount of percolation is small, 
 a narrow wall only four feet thick between the sea and the 
 workings cannot be left without fear of trouble and danger from 
 water above. 
 
 Dams. In addition to preventing the access of water from 
 the surface, it is advisable to cut off underground inflows as far 
 as practicable. In the chapter upon supporting ground, imperme- 
 able linings of shafts and levels have been described, and where water 
 can be shut out by tubbing or by coffering, the mine-owner is 
 saved the constant expense of pumping ; indeed, he is sometimes 
 thus enabled to work deposits which he would not be able to 
 reach if he had to fight against the enormous streams issuing 
 from certain strata. Water from adjacent abandoned workings 
 is shut out by dams that is to say, artificial stoppings placed 
 in levels or shafts. They may be made of timber, brickwork, 
 masonry or concrete, and, when intended for temporary purposes, 
 of iron. 
 
 In erecting a dam the first consideration is the choice of a 
 suitable place, for it is useless to take the trouble to put in a 
 stanch stopping unless the ground is firm enough to support it, 
 
 and free enough from cracks to 
 prevent the water behind it from 
 finding its way round to the 
 front. 
 
 If the ground is thoroughly 
 strong, a dam may be put in by 
 cutting a recess in the sides of 
 the level, as represented by 
 Fig. 491,* and stopping the 
 water back by a wall made of 
 horizontal balks of timber. Oak 
 is usually chosen for the purpose. 
 Before the timber is put in, the 
 rock is very carefully dressed until the surface is perfectly 
 smooth, and ready to receive a similar surface of wood. Each 
 balk is wedged up against the side just in the same way as a 
 wedging curb, and the joints between the separate balks are 
 caulked. 
 
 * Gallon, Lectures on Mining, vol. ii., \ late Ixxvi. 
 
DRAINAGE. 
 
 For heavier pressures the spherical dam is available; it is 
 constructed of wooden logs placed longitudinally and wedged up 
 very tightly. A wooden dam of this kind has the advantage that 
 it will yield a little if there are movements of the ground, whereas 
 a dam constructed of bricks might become cracked and leak so 
 badly as to be almost useless; the wooden dam is also more 
 easily repaired. Oak, pine, and fir are all employed for 
 making dams ; the two latter are sometimes preferred to the 
 former, because they are more easily wedged. The following 
 account of a spherical dam is based upon a description written by 
 Gatzschmann * (Figs. 492 to 495). 
 
 FIG. 492. 
 
 FIG. 493. 
 
 A nail is fixed upon a cross-piece in the middle of the level, about 
 23 feet (7 m.) from the proposed outer face of the dam, and the sides 
 of the level are trimmed smooth with the greatest care along planes 
 which would intersect in this point as a centre. Pieces of timber 
 are cut in the form of truncated pyramids, the four faces of which 
 converge to a centre agreeing with that chosen underground ; 
 they are fitted together at the surface, with the horizontal 
 joints arranged along the lines of the same great circles of the 
 sphere and the vertical joints alternating. When the logs have 
 been duly fitted, the work of putting them in is begun. Tarred 
 canvas is placed upon the floor of the level and the first row of 
 
 * Jahrbuchfur den Berg- und Hiitten- Mann auf das Jalir 1841 , Freiberg. 
 Combes, Traite deV Exploitation des Mines. Paris, 1884, vol. ii., page 121, 
 and plates. 
 
432 
 
 ORE AND STONE-MINING. 
 
 pieces laid down ; the last piece acts as a keystone and is driven 
 in with a sledge. One of the pieces of the second layer has a 
 hole bored through it so as to let off any water during the progress 
 of the work. When the middle of the dam is reached, a flanged cast- 
 iron pipe is put in as a man-hole, and the other rows are built up to 
 the roof, which has been covered with tarred canvas : a hole is bored 
 through one of the pieces of the uppermost row but one and fur- 
 nished with a bent pipe, which serves to carry off the air at the top 
 when the dam is finally closed. The joints between the logs are 
 made watertight by driving in wedges around them obliquely ; the 
 first wedges are of pine, the next are of hard wood, and the final 
 set are of iron. A coating of cement, made of cart-grease, tar 
 FIG. 494. 
 
 495. Fia. 
 
 and slacked lime, completes the outer face of the dam. The 
 miners then close the water-hole with a plug made of beech, and 
 after retiring through the man-hole, draw into it a huge wooden 
 stopper. The water is allowed to rise, and in due course some 
 passes out by the air pipe ; the air-hole is then plugged, and the 
 inside face of the dam is wedged up in the same manner as 
 the outside. When exposed to considerable pressure a spherical 
 dam of this kind is found to slide inwards a little. One which 
 was put in at Churprinz Mine, Freiberg, shifted 19! inches 
 (0.50 m.) in the first fourteen hours after it had been closed, and 
 23! inches altogether in the first ten days ; after that the motion 
 was exceedingly slow, in fact, almost imperceptible ; but it did 
 not absolutely cease for several years. 
 
 Fig. 496* is a dam in an abandoned shaft, intended to shut 
 
 * Callon, Lectures on Mining, vol. ii., plate Ixxvi., fig. 409. 
 
DRAINAGE. 
 
 433 
 
 FIG. 496. 
 
 off any possible influx of water into the adjacent workings in 
 
 case the tubbing should fail. It consists of a strong arch of 
 
 masonry, covered by a thick layer of clay and a pavement of 
 
 stones. The clay will keep the dam stanch even if the masonry 
 
 becomes slightly cracked from 
 
 movements of the ground, 
 
 and the object of the stone 
 
 pavement is to prevent the 
 
 clay from being washed away 
 
 suddenly in the event of a 
 
 large crack being formed. The 
 
 vertical pipe serves to carry 
 
 down the water during the 
 
 erection of the dam. 
 
 A temporary dam is some- 
 times required close to a shaft, 
 in order to keep back the 
 water of the mine, and pre- 
 vent it from drowning the 
 pumps while they are being 
 repaired. A strong and 
 tightly-fitting hinged door 
 may suffice for the purpose; 
 in the Furness district the 
 door-frame is set in a very 
 massive structure of concrete, 
 brickwork and steel rails. A 
 large pipe is put in at the 
 bottom and fitted with a good 
 valve, which enables the water 
 to be let out gradually when 
 the pumps are once more 
 ready for work. 
 
 In spite of all precautions o~ 
 the miner generally has to 
 
 contend with water which percolates into the workings. Four 
 methods of getting rid of it are available viz., drainage tunnels, 
 siphons, winding machinery and pumps. 
 
 DRAINAGE TUNNELS. An adit, day-level, or sough, is a 
 nearly horizontal tunnel with one end opening at the surface, 
 allowing the water to drain away naturally. In hilly countries 
 mines are often worked entirely by adits, and even for the deeper 
 workings the adit presents several advantages: it lessens the 
 quantity of water percolating into them ; it diminishes the height 
 to which the water has to be pumped ; if the contour of the sur- 
 face permits it, its outflow may be utilised for producing water 
 power; and lastly, it affords a natural discharge for water used in 
 driving hydraulic engines underground. On account of these 
 
 2 E 
 
 SCALE 
 
 3 METRES 
 
 2 3 4, 5 6 7 8 9 10 II 12 13 FEET 
 
434 ORE AND STONE-MINING. 
 
 very important advantages, some long and costly adits have been 
 driven in certain metalliferous districts. 
 
 Thus in the Hartz, the Ernest Augustus adit or drainage tunnel, 
 (" Ernst August Stolln") has been driven a distance of nearly 6J 
 miles into the Clausthal district. The total length of the adit, 
 including its branches, is no less than 14 miles. It intersects 
 many of the lodes at a depth of 400 yards from the surface. The 
 total cost of this adit is estimated at ,85,500.* 
 
 Another long adit is the celebrated " Rothschonberger Stolln," 
 which unwaters some of the most important mines at Freiberg in 
 Saxony. The length of the main or trunk adit is more than 8J 
 miles; the gradient of the greater part of it is only n8 inch in 
 100 yards. Branches of this adit among the mines are more 
 than 1 6 miles in length, so that the total length of the main 
 tunnel with its ramifications amounts to about 25 miles. Most 
 of the mines are now drained by it to a depth of 250 to 300 yards. 
 The cost of the main tunnel was .359,334, or nearly ^24 per 
 yard, but this includes the cost of eight shafts, heavy expenses 
 for pumping from these shafts, the walling of the adit for | mile, 
 and all general exper ses. The length of time occupied in driving 
 this adit was thirty-three years. 
 
 The " Kaiser Josef Erbstolln," in Hungary, is another remark- 
 able mining tunnel, which was commenced in 1782 and com- 
 pleted in 1878, at a total cost of 4,599,000 florins. It is loj 
 miles in length, extending from the river Gran to the town 
 of Schemnitz, where it intersects the lodes at depths vary- 
 ing from 300 to 600 yards according to the contour of the 
 surface. 
 
 In Bohemia I may mention the " Kaiser Josef II." adit which 
 drains the Pribram mines. The length from the mouth to the 
 Stefan shaft is 4^ miles, and the side branches bring up the 
 total length to 13! miles. 
 
 The great adit of the Mansfeld copper mines was begun in 
 1809, and was seventy years in course of construction. It reaches 
 from Friedeburg on the Saale to Eisleben. The first part was 
 driven across the measures, and is, in fact, a crosscut, and it was 
 then continued along the strike of the cupriferous seam. The 
 total length is now 21 miles (33,900 m.). All the workings below 
 its level, extending for a distance of more than n miles (18 km.), 
 have their water pumped into it. The adit was driven with 
 a rise of i in 7200 (J inch in 100 yards). It is 9 feet 10 inches 
 high (3 m.), and 6 feet across (1*85 m.), in the middle where it is 
 widest. The bottom part, 5 feet 8 inches in height, was carefully 
 kept in the Rothliegendesso as to prevent percolation into the work- 
 ings. Cross-timbers (spreaders) were put in about 5 feet above the 
 
 * Bauerman, "Note on the new deep adit in the Upper Hartz Mines," 
 Trans. Min. Asi>oc. Cor me all and Devon, 1868, p. n. 
 
DRAINAGE. 435 
 
 floor and serve to support a single line of rails and a gangway of 
 planks.* 
 
 The adit at Monteponi,f in Sardinia, recently finished, is 3f 
 miles (6 kil.) in length, and relieves the mine of its water for au 
 additional depth of about 160 feet (50 m.). 
 
 The great County adit in Cornwall was driven for the purpose 
 of draining the Gwennap copper mines, and it was pushed on 
 to Redrutb. This adit differs from those just mentioned by 
 the fact that it commences in the mining district itself, and 
 though the length of all the drivages amounts to more than 30 
 miles, the water from the most distant mine does not run more 
 than 6 miles before reaching daylight. The average depth is 
 only 70 or 80 yards from the surface. In fact this great adit, 
 though a work of great utility when the Gwennap district was in 
 a flourishing condition, is merely a network of shallow tunnels, 
 often driven along the lodes themselves, and therefore for bold- 
 ness of execution cannot for one moment be compared to the 
 great adits in Germany and Hungary. 
 
 The Blackett level in Northumberland is an adit which has 
 been driven a distance of about 4f miles, and which will have 
 to be extended about 2 miles further before arriving at Allen- 
 heads. Its depth from the surface at that place will be about 200 
 yards. 
 
 The main part of the Halkyn tunnel in Flintshire has now 
 reached a total length of 4 miles. The branch which goes out to 
 Rhosesmor Mine is nearly half a mile long and a second branch 
 has been commenced. The greatest depth from the surface is 230 
 yards, and the average depth under Halkyn Mountain about 215 
 yards. The length and depth of the adit are not remarkable ; but 
 the quantity of water discharged is a matter of interest and impor- 
 tance. It is estimated that this adit is now discharging 15 
 million gallons or 66,000 tons of water in 24 hours, although the 
 outflow is purely natural, for no mines are pumping water into it, 
 It is easy to understand that the Rhosesmor Mine, though 
 provided with powerful pumping machinery, was unable to cope 
 with the springs it encountered. 
 
 In the United Kingdom, where the land and the minerals are 
 parcelled out among various owners, an undertaking of this 
 kind requires a special Act of Parliament, for otherwise one 
 obstinate proprietor might bar the way altogether, or mines 
 drained by the adit might refuse to pay for the advantages they 
 received. Before the Halkyn tunnel was driven, the area which 
 appeared likely to be benefited was duly determined, and the 
 
 * Der Kupferschieferbergbau und der HiiUenbefritb zur Verarbeitung der 
 gewonnenen Minern in den beiden Kreisen der Preuss. Prov. Such sen. Halle 
 an der Saale, 1889, page 48. 
 
 t Pellati, "I Progress! nelle Industrie Minerarie e Mineralurgiche 
 Italiane," Industria, vol. v., 1891, p. 637. 
 
436 ORE AND STONE MINING. 
 
 mines now worked within it have to pay a royalty to the 
 tunnel company for every ton of ore they raise. 
 
 Fired by the success of the Halkyn adit, which has proved a 
 lucky investment for the shareholders, a company has lately 
 commenced driving a similar tunnel in the Llanarmon district. 
 
 The United States may fairly boast of the Sutro Tunnel, which 
 enters the workings on the Comstock lode at a depth of 1700 feet 
 from the surface. Work was begun on a small scale in October 
 1869, and the tunnel was "holed" into the workings of the 
 Savage Mine in July 1878. The length of the main tunnel is 
 3 1 miles, and the cost of excavating it and timbering it up to the 
 date of its completion, September i, 1878, was $1,367,577. To 
 this must be added $296,724 for enlarging the heading, $384,824 
 for cutting a drainage channel at the bottom of the tunnel and 
 lining it with wooden launders or drain boxes, and the cost of 
 repairs $43,441, making the total cost of the main tunnel up to 
 October 1881, $2,096,566. This sum does not include the expenses 
 of management of the company.* 
 
 The size of the adit at first was 10 feet high clear and 15 J feet 
 wide ; but after 366 yards had been driven the dimensions were 
 reduced to 6 feet high clear by 5 feet wide. 
 
 In the original scheme it was proposed to sink four shafts and ex- 
 pedite the work by having nine points of attack ; however, this plan 
 could not be carried out. The first two shafts were sunk down to the 
 level of the tunnel, but the quantity of water met with proved such 
 an obstacle that the tunnel was practically driven entirely from 
 one end. 
 
 Work with machine drills was begun in April 1874, and the 
 height of the heading was raised to 9! feet, and the width to 13 
 feet, both outside the timber. In 1875 and 1876 the monthly 
 progress was on an average 308^ feet. Much of the tunnel, 
 indeed 45-5 per cent, of the total length, had to be timbered. 
 
 In addition to the main tunnel there are branches along the 
 course of the lode. In October 1880, the length of the north 
 branch was 4403 feet, and that of the south branch 4114 feet. 
 Both branches are 8 feet in width by 7 in height clear. 
 
 The quantity of water running out daily in 1879 was 12,000 
 tons, at a temperature of 123 F. (50*5 C.) when leaving the mouth 
 of the tunnel. All this water would otherwise have been pumped 
 to the surface, at a cost estimated at $3000 a-day. 
 
 The obstacles to the progress of the work were very great ; not 
 only was the heat extreme, but swelling ground was encountered 
 which snapped the strongest timber. Thanks, however, to the 
 untiring energy of Mr. Adolph Sutro, the difficulties were at 
 
 * Eliot Lord, "Comstock Mining and Miners." Monographs of the U. S. 
 Geol. /Survey, vol. iv., p. 342. Washington, 1883. There is an error of 
 $4000 either in one of the items or in the total ; but I give the figures as 
 they stand in the Report. C. L. N. F. 
 
DRAINAGE. 437 
 
 .last successfully overcome, and this great work will long remain 
 as a monument to his foresight, skill, and patient pertinacity. 
 
 The Atlantic-Pacific tunnel, which was commenced in 1880 and 
 then stopped for a time, is intended to pierce the heart of the 
 Rocky Mountains, under Grey's Peak, Colorado. It will be 
 driven from both sides of the watershed, and will have a total 
 length of 4j miles from end to end. 
 
 SIPHONS. Siphons are used for draining mines in a few 
 special cases in which the barrier over which the water has to be 
 raised is very decidedly less than 33 feet. 
 
 The workings of a shallow mine in North Wales are kept clear 
 of water by a siphon made of i J-inch gas-pipe. At the crown 
 there is an iron tank full of water, the contents of which 
 can be run into the siphon by a 3 -inch pipe in order to starfc 
 it. 
 
 At Mountfield gypsum mine, in Sussex, the water is brought to 
 the shaft from the neighbourhood of the working-face, a distance 
 of 300 yards, by a siphon also made of i^-inch gas-pipe. It has 
 two branches, but only one is working at a time. The water 
 is lifted a height of 22 feet. When the water in the workings sinks, 
 so that there is a danger of the siphon running dry, the foreman 
 moves a lever which brings a pad of india-rubber against the outlet 
 of the pipe, and so keeps it full and ready to act the next time it is 
 wanted. A force pump is set up at the far end of the workings 
 for filling the siphon if by any chance the water has run out. 
 
 WINDING MACHINERY. When a mine cannot be 
 drained by tunnels or siphons, it is necessary to raise the water 
 mechanically, either to the surface, or at all events to an adit 
 through which it can flow out naturally. If the quantity is not 
 excessive, it is often convenient to use the winding machinery, 
 and draw up the water in special buckets (water-barrels) or tanks. 
 The bucket may be tilted over on reaching the surface, or it may 
 be emptied by opening a valve at the bottom. 
 
 This means of raising water is commonly adopted in sinking 
 shafts, when it may be desirable to wait till the whole or a 
 portion of the pit is completed, before putting in the final pump- 
 ing machinery. The water is usually lifted by hand into the 
 bucket or tank, an operation involving a good deal of labour. 
 Some of the baling may be avoided by collecting as much as 
 possible of the inflow in a cistern above the bottom, and drawing 
 off its contents by a hose into the bucket. This device is of no 
 use for the water actually at the bottom, but baling may be dis- 
 pensed with even in this case by the adoption of an ingenious 
 arrangement invented by Mr. Galloway, and applied very success- 
 fully by him in sinking a shaft near Cardiff* (Figs. 497 and 
 498). 
 
 * "Sinking Appliances at Llanbradach," Trans. South Wales last. Eiiy. 
 vol. xvi., 1888, p. 117. 
 
43S 
 
 ORE AND STONE-MINING. 
 
 By means of a pump at the surface, the air is constantly being 
 exhausted from a pipe, which descends the shaft and terminates 
 in a long piece of flexible hose provided with a stopcock. When 
 the cylindrical water-barrel has been lowered to the bottom of the 
 
 FIGS. 497, 498. 
 
 o, door for entering barrel 
 if required ; 6, flat cast- 
 iron valve attached to the 
 spindle h; c d, bottom 
 plate of the barrel ; e, sec- 
 tion of the valve showing 
 universal joint attach- 
 ment ; I, water-pipe, pro- 
 vided at the end k with 
 a coupling to which the 
 suction hose is attached ; 
 m, water-gauge. 
 
 shaft and is standing with its base in 
 water, the flexible hose is quickly 
 attached to it at the point k by an 
 instantaneous coupling, and the cock is 
 turned. Water is at once sucked up 
 through the valve 6, and as soon as the 
 gauge-glass in shows that it has reached 
 the desired height, the stopcock is 
 closed and the hose uncoupled. On 
 arriving at the top of the pit, the water- 
 barrel is lowered on to a trolley carry- 
 ing a projecting conical block of wood, 
 which knocks up the valve and allows 
 the contents to run out. 
 
 It was possible with the aid of this 
 contrivance, while sinking a shaft in 
 hard sandstone at the rate of 5 to 5 J 
 yards per week, to cope with an influx 
 of 5000 gallons (227 cubic metres) of 
 water per hour at the bottom. 
 
 A water-barrel can be filled auto- 
 matically, when it can be made to 
 plunge into a deep cistern or collect- 
 ing pit (sump). Mr. Galloway's 
 arrangement is shown by Figs. 499 and 
 500. The former represents his auto- 
 matic water-tank with one side partly 
 removed : a is the winding-rope, b the 
 tank, which is guided in its descent and 
 ascent by the studs c (Fig. 500) run- 
 ning upon the guide ropes e. At the 
 surface the tank is further steadied by 
 side grooves, made of angle-iron d, 
 which clasp the studs. When the tank 
 
 is lowered into the cistern, the valve k opens of itself and lets the 
 water rush in. It is then wound up to the top, where the short lever 
 at o comes in contact with the piece of timber p ; the rod attached 
 to the valve is lifted, and the water rushes out by the sloping 
 mouth f into the wooden trough or launder m. The bar p is 
 movable about the point q, but it is kept down by the weight u 
 attached to the chain s ; t is one of the pieces of timber to which 
 the fixed guides are fastened, and lastly, w is the suspending bow 
 which passes quite round the tauk and forms a projecting loop at 
 the bottom. This bow protects the bottom of the tank while it 
 
DRAINAGE. 
 
 439 
 
 is standing in the cistern. The tank holds 212 gallons (963 
 litres), and can be drawn up 24 times an hour from a depth of 
 
 * IG. 499. 
 
 190 yards; it is therefore capable of raising 5000 gallons (22"] 
 cubic metres) in that time. 
 
 The arrangement just described was employed by Mr. Galloway 
 when sinking, but it is equally available as a permanent method 
 
440 
 
 ORE AND STONE-MINING. 
 
 FIG. 500. 
 
 of drainage when the quantity of water is not considerable. 
 The water is allowed to accumulate in a sump at the bottom 
 of the shaft during the day-time, for instance, and at night, when 
 no mineral is being wound, the ordinary cage is taken off and 
 the water-barrel substituted for it. 
 The water-barrel is also useful as an 
 auxiliary, when the ordinary pumping 
 machinery of a mine is unable to cope 
 with some unusual influx of water, or 
 has to be stopped for repairs. It is 
 not necessary to adopt the construction 
 shown in the figure, though that is a 
 particularly advantageous one. The 
 vessel for receiving the water and 
 bringing it up is sometimes made like 
 a large mine waggon ; it is drawn up 
 in the cage, like a " tub " of mineral, 
 and is discharged at some point in 
 close proximity to the pit-top. At the 
 Van mine a tub of this kind holds 
 about 220 gallons (i cubic metre). As 
 a makeshift, an ordinary mine-skip 
 may be turned into a water-barrel by 
 fixing a wooden box inside it with a 
 valve in the bottom. 
 
 Automatic emptying and filling is 
 also obtainable where the mine is 
 worked by inclines or "slopes," and 
 the arrangement used by Mr. Bowden* 
 (Figs. 501 to 503) has the merit of 
 allowing seveial tanks to be used in 
 the place of a single large one, which 
 might be too unwieldy for the mine. 
 Each tank has an iron door at the rear 
 end opening inwards, and a wooden 
 door at the front end opening out- 
 wards. The front door is attached 
 to the back door by an iron rod, so 
 that it is held down as long as the back 
 
 door is shut ; however, the back door can open independently of 
 the front door, because the rod has a sliding link at the rear end. 
 The tipping or dumping is effected by the small wheels above the 
 rear axles. They have a wider gauge than the regular wheels, 
 and as each tank comes up to the surface, they are taken by an 
 upper set of rails and tilt up the rear end. If the track upon 
 which they travel has sufficient gradient towards the " slope/' the 
 
 * Bowden, " Tandem Tanks for Hoisting Water from Flooded Slopes " 
 Trans, Amer. Imt> JiL E., vol. xx., 1891, p. 343. 
 
DRAINAGE. 
 
 441 
 
 tanks will run down of themselves, after they have emptied their 
 contents into the trough at the top. 
 
 PUMPS. We now come to the main division of the subject of 
 drainage, for the standard method of extracting water from 
 underground workings is by some form of pump. 
 
 The varieties of pumps used in mines are numerous. In small 
 sinkings, hand-pumps, either direct-acting or rotary, may be 
 applied; steam -jet pumps, on the principle of the Giffard 
 injector, and pulsometers are also used, but when we examine the 
 
 FIGS. 501, 502. 
 
 FIG. 503. 
 
 
 TAKKI CUHPIM t HUB or He**, 
 
 permanent machinery erected at large mines of considerable 
 depth, we find that the prevailing types of pumps are few. 
 
 They may be classified, according to the situation of the engine 
 working the pumps, into : 
 
 I. Lifting pumps and force pumps worked by power transmitted by 
 rods from an engine at the surface or in the upper workings. 
 II. Force pumps worked direct from an engine immediately attached 
 to them at or near the bottom of the workings. 
 
 Class I. Engine at or near the Surface, Power Trans- 
 mitted by Rods. 
 
 We may consider the subject under the following four heads : 
 
 (a) Motors. 
 
 (b) Rods. 
 
 (c) Pumps. 
 
 (d) Accessory arrangements ; counterbalances, regenerators, catches. 
 
442 ORE AND STONE-MINING. 
 
 (a) Motors. The engine may be driven by wind, compresped 
 air, water, electricity, steam, or petroleum, (i) Air. Windmills 
 have the disadvantage, which is often fatal, that the power is not 
 constant ; the same may be said of water power derived from 
 brooks and rivers, which sometimes dry up ; but the two cases 
 are different. Streams dry up slowly and gradually, whilst air 
 currents spring up or die away suddenly. By erecting an 
 auxiliary steam engine, which can be set to work if the wind 
 fails, the evil is overcome ; and this remedy is adopted at the 
 Mona mines in Anglesey, where a windmill has been in use for 
 many years for working pumps. It raises water from a depth 
 of 80 fathoms at the rate of about 90 gallons a minute. As the 
 site of the mine on Parys Mountain is breezy, there is wind 
 enough to work the mill for about one-half of the time pumping 
 is required. A very large saving has thus been effected in the 
 coal bills. 
 
 (2) Water. Water power was for a long period the principal 
 agent employed in draining mines, and it is still of the greatest 
 use in many districts, reservoirs being constructed to collect and 
 store the rainfall. Some idea of the scale upon which works of 
 this kind are conducted will be gathered from the following 
 figures relating to the Hartz mines.* In 1868 there were 
 "sixty-seven reservoirs, covering an area of 604 acres, and 
 having a total storage capacity of 336 millions of cubic feet." 
 
 The total length of the various leats, races, and other water- 
 courses, including the six principal adits, is about 170 statute 
 miles. The net power extracted is reckoned at 1870 horse-power, 
 but less than one-fourth of this is used for pumping. 
 
 Water power is applied to pumping machinery by water- 
 wheels, turbines, and rotary or non-rotary water-pressure engines. 
 Excepting in the case of the latter, the rotary motion has to be 
 converted into a reciprocating motion by a crank ; and further- 
 more with turbines, the speed must be reduced very considerably 
 by intermediate gearing. 
 
 Overshot wheels are the commonest forms of prime movers 
 for working pumps by water-power ; they are frequently from 
 40 to 50 feet in diameter, and at Great Laxey Mine, in the 
 Isle of Man, one of the wheels is no less than 72 feet 6 
 inches in diameter, and 6 feet in the breast. The power is con- 
 veyed from the water-wheel by a connecting rod to a quadrant 
 or " bob," like a bell-crank, placed above the shaft, and when, 
 owing to the contour of the ground, the wheel has to be erected 
 at a distance, it is often connected to the bob by the so-called 
 " flat rods," which are beams of wood, bars of iron, or pieces of 
 wire rope. They are supported by pulleys or upright oscillating 
 
 * Bauerman, " Notes on the New Deep Adit in the Upper Hartz Mines," 
 Rep. Miners' Assoc. Cornwall and Devon, 1868, p. 21. 
 
DRAINAGE. 443 
 
 beams, and travel backwards or forwards with the motion of the 
 crank. 
 
 Water-pressure engines share with turbines the advantage of 
 being able to utilise any amount of fall, and the direct-acting 
 water-pressure engine can be applied immediately to the mam 
 rod of the pumps. 
 
 (3) Steam is, however, the power used par excellence for working 
 pumping machinery, and the great inventions of Newcomen and 
 Watt owed their birth to the necessities of mines, which could rio 
 longer be drained by the water power available on the spot. 
 
 The principal type of engine is that known as the Cornish 
 engine ; it is a single-acting condensing beam engine, working 
 expansively, having the number of strokes regulated by an 
 arrangement called a cataract. The cylinder of the Cornish 
 engine is sometimes inverted and stands over the shaft, the main 
 rod of the pumps being attached directly to the piston-rod. This 
 type of engine, known as the Bull engine in Cornwall, dispenses 
 with the heavy beam, but it has the great disadvantage of 
 obstructing the mouth of the shaft. This objection is quite 
 enough to forbid its use under ordinary circumstances. On the 
 other hand, the mere reversal of the cylinder or cylinders, while 
 retaining the beam, is often resorted to on account of the 
 advantage it gives in greater stability and diminished cost of the 
 engine-house. 
 
 A disadvantage of the Cornish engine is the fact that when it 
 works with a high rate of expansion, there are great shocks and 
 jars to all the parts of the machinery. The heavy mass of rods 
 and its connections is started with a jerk, and naturally all the 
 joints must suffer. 
 
 The compound engine, invented by Woolf and tried many years 
 ago in Cornwall, starts more gradually and causes less strain upon 
 the pump-rods and machinery generally. The cylinders may be 
 placed one above the other, or side by side. At Ernst IV. shaft, 
 Mansfeld, there are three cylinders placed side by side across the 
 line of the beam, the high-pressure cylinder in the middle between 
 the two low-pressure cylinders. The three piston-rods are attached 
 to a crosshead which is connected to the beam. The cylinders 
 are inverted. 
 
 Kley, of Bonn, has constructed compound engines with steam 
 acting on both sides of the pistons. He makes the excess of the 
 weight of the rod over that of the counterbalances sufficient 
 to raise only half the weight of the water and to overcome the 
 friction ; and then in the descending stroke of the rod the steam 
 again acts upon the pistons and so makes up for the insufficiency 
 in weight. As the steam acts upon both sides of the piston, the 
 same amount is consumed, it is true ; but a smaller cylinder will 
 do the work, and the original cost of the engine is lessened. 
 
 Fly-wheels have the advantage of setting the pumps arid main 
 
444 
 
 ORE AND STONE-MINING. 
 
 rod in motion without the. injurious jerk which is inseparable 
 from the Cornish engine worked at a high rate of expansion, 
 besides reducing the risks of damage if a piston-rod breaks. 
 
 Kley has put up several pumping engines in Belgium, France, 
 and Germany, of 30 to 560 horse-power, with a fly- wheel which 
 serves solely to regulate the stroke of the piston, so that the 
 crank always stops before or after the dead point till the cataract 
 starts another stroke. The machines are double-acting compound 
 beam engines. 
 
 M. Guinotte, the well-known Belgian engineer, also adopts the 
 fly-wheel, and the machines he has erected at Mariemont and else- 
 where are single-acting rotary engines with one cylinder. The 
 peculiarity of his fly-wheel is that he can weight it in any way he 
 pleases ; and he so overcomes the diificulty which occurs in other 
 rotary machines of its being impossible to work them below a certain 
 His object is to make the speed slow at the beginning and 
 
 FIG. 504. 
 
 end of the stroke, so as to avoid the injurious shocks to the 
 valves and machinery generally from sudden starts and stoppages. 
 The cylinders of a pumping engine may be placed horizontally, 
 an arrangement which effects a decided saving in the cost of 
 foundations and in that of the engine- house. The engine lately 
 erected at the Otto IV. shaft at Mansfeld (Fig. 504) is a 
 horizontal double-acting compound engine with a fly-wheel, 
 working two pump-rods by means of quadrants. A is the high- 
 pressure cylinder, B the low-pressure cylinder, C the fly-wheel, 
 D and E are quadrants, connected by F, which raise and lower the 
 two rods G and H. The cylinder A is 5 feet 2^ inches (i'59o 
 m.) in diameter, and B 8 feet i \ inches (2*480 m.). The stroke 
 of the engine is 8 feet 8f inches (2-660 m.), and the fly-wheel 
 makes nj revolutions per minute. When working at this speed 
 it is reckoned that it raises 3521 gallons (16 cubic metres) of 
 water per minute, a total height of 906 feet (276*35 m.). The 
 water is salt, and has a specific gravity of 1*15. Each rod works 
 a pump at the bottom, with a fixed hollow plunger 27! inches (705 
 mm.) in diameter and a moving " pole case," which lifts the water to 
 a height of 463 feet (141*1 m.). Here the work is taken up by a 
 
DRAINAGE, 445 
 
 Rittinger pump with plungers of 27 J inches (700 mm.) and 21 J 
 inches (540 mm.), and the water is raised by it to the adit level, 
 an additional height of 443 feet (135*25 m.). The stroke of the 
 rods is 2 metres. When the full power of the engine is not 
 required, one rod can be disconnected and the other is balanced 
 by an accumulator. 
 
 At Diepenlinchen, near Stolberg, an engine of similar construc- 
 tion has been put up within the last few years, the dimensions of 
 the two cylinders being almost the same as those adopted at 
 Mansfeld. The problem at Diepenlinchen is to raise 2640 gallons 
 (12 cubic metres) of water per minute from a depth of 328 yards 
 (300 m.). 
 
 The compound engine, with its two cylinders placed tandem 
 fashion horizontally, is largely used by Davey, whose principal im- 
 provement consists in his patent differential valve gear, which 
 combines the action of a cataract with that of a slide valve. 
 
 (4) Petroleum. Where coal is very expensive owing to the cost 
 of carriage, a petroleum engine may be a convenient source of 
 power for pumping on a small scale. 
 
 (b) Bods. Having discussed the principal forms of engines 
 used for pumping at mines, it now remains to consider 
 how their power is applied to the pumps themselves. FIG. 505. 
 
 The usual mode of transmission is by rods made , 
 of wood, wrought iron, or steel. 
 
 Wooden rods are commonly constructed in this 
 country of pitch-pine beams of square section, united by 
 plates of iron or mild steel (strapping plates, a, b, c, 
 Fig. 505), which are held together by bolts, the butt end 
 of one beam being brought against the butt end of the 
 next. Other forms of joints, such as the scarf joint, 
 are met with. 
 
 The iron and steel rods are either solid bars of round 
 iron or steel, or beams built up from angle-iron or 
 angle-steel, so as to obtain the desired stiffness without 
 undue weight. It is proposed to use Mannesmann 
 seamless steel tubes, which can be rolled in lengths of 
 70 feet, as rods for pumps. 
 
 The long beam, made up of a succession of pieces, 
 constitutes what is called the main rod or spear-rod. 
 It hangs down the shaft, either from the end of the 
 beam of the engine, or from a quadrant such as is 
 shown in Fig. 504, when the cylinder of the pumping engine 
 is horizontal. In order to prevent it from vibrating sideways, 
 it has to be guided; wooden rods are guided by cross bars of 
 timber placed in the shaft, and they are protected from wear by 
 pieces of plank (lining boards), which are renewed from time to 
 time. The round iron or steel rods are kept, in position by 
 suitable collars fixed upon timber or metal supports. 
 
446 
 
 ORE AND STONE-MINING. 
 
 FIG. 506. 
 
 If the shaft is inclined, as so often happens in vein-mining, the 
 main rod has to be supported at suitable intervals by cylinders of 
 cast iron or steel, known as " shaft rolls." The roller turns upon 
 a spindle as the main rod moves up and down (Fig. 539). 
 
 The bane of some mining districts, such as Cornwall, is the 
 varying inclination of many of the pumping shafts, which have 
 
 been sunk along the dip of 
 the veins. In cases of this 
 kind it is necessary to make 
 bends in the main rod cor- 
 responding to the crooked- 
 ness of the shaft. Four 
 methods of making an 
 angle in the rod are : (i) 
 the V-bob;* (2) the fend- 
 off bob \ (3) the running- 
 loop ; (4) hydraulic pistons. 
 The V-bob, as its name 
 
 FIG. 507. 
 
 XE 
 
 
 implies (Figs. 506 and 507), 
 is a V-like frame, some- 
 thing like a bell-crank, in- 
 terosed between the ends 
 
 of the two rods. The two arms of the V are made of strong 
 beams of timber strengthened by iron plates b and c, and con- 
 nected by two straps a, which prevent their being pulled apart. 
 The arms are arranged so that each is at right angles to the 
 
 FIG. 508. 
 
 adjacent end of the rod at half stroke. At the point of the V 
 there is a strong pin d lying in brasses, about which the bob 
 moves as a centre. It is usual to make the arms at least 20 
 
 * This figure and several of the others relating to pumps are copied, by 
 permission, from a paper on " Cornish Mine Drainage," by Mitchell and 
 Letcher. Forty third Ann. Rep. It. Cornwall Pol. 8oc. t Falmouth, 1875. 
 
DRAINAGE. 
 
 447 
 
 inches long for each foot of the stroke. Therefore for a stroke 
 of 9 feet, the length of each arm would be 9 x if, or 15 feet. 
 
 A fend-off beam will be understood from Fig. 508, which 
 is an example taken from Crenver and Abraham Mine in 
 Cornwall. It is a long beam, strengthened by tie-rods, moving 
 about a strong pin working in a block. The Cornish rule is to 
 make the beam 2\ times as long as the stroke. 
 
 The running loop (Figs. 509 and 510) is sometimes used to 
 save the expense of cutting out the large recess (plat) which is 
 required in the case of a V-bob or a fend-off beam. The two parts 
 of the main rod, c and d, are connected by two loops of wrought 
 
 FIG. 509. 
 
 FIG. 510. 
 
 FIG. 511. 
 
 Side View. 
 
 Front View. 
 
 iron, e, of which one only can be shown in the side elevation. 
 Each loop passes round the two pins, which are the axles of 
 the two wheels. Ths wheels run upon flat bars of wrought-iron, 
 /, laid upon the sleepers, b, which are supported by the strong 
 cross : bearers, a a. 
 
 West and Darlington effect the change of direction in the rods 
 by two rams or plungers, working in cylinders connected at the 
 bottom (Fig. 511). The plunger a in going down raises the 
 plunger b, to which the main rod of the pumps is attached by a 
 crosshead and two side straps. There is a valve at c, through 
 which the plunger can draw in a little water to make up for any 
 loss through the stuffing boxes. 
 
 (c) Pumps. The main rod, which has just been described, is 
 used for transmitting the motion of the engine to a pump or 
 several pumps in the shaft. These pumps are of two descrip- 
 
443 ORE AND STONE-MINING. 
 
 tions: (i) lifting pumps; (2) force-pumps. The lifting pump, 
 or drawing lift (Fig. 512), consists of the wind-bore or suction 
 pipo, the clack-piece or valve-box, the clack-seat piece, the working 
 barrel, the bucket with its rod and the column. 
 
 The wind-bore, or snore-piece, as it is sometimes called, is a 
 cylinder of cast-iron, terminating in an egg-shaped or a flat bottom, 
 with a number of holes through which the water is sucked up 
 into the pump. . 
 
 The clack-piece is a short cylinder of cast iron with a flat side 
 door fastened on by bolts, the object of which is to enable the 
 valve to be taken out and renewed. It receives the seat on which 
 a clack or valve works. 
 
 The clack seat-piece is not always used ; but it is often put 
 in as a matter of precaution, in case the regular valve should 
 accidentally fail while the pumps are under water. If a mishap 
 of this kind occurs, a special clack can be lowered on to the 
 clack seat-piece, and the pump can be worked with it temporarily. 
 
 The working barrel is a cast-iron cylinder, carefully bored so 
 that the bucket may work in it smoothly and exactly ; occasionally 
 it is bushed with brass. 
 
 The bucket is merely a moving valve, consisting usually of a 
 hollow cylinder of cast iron, surrounded by a band of leather or 
 gutta-percha, and attached to a rod through which it receives its 
 reciprocating motion. The seat, called the " form," may be made 
 for a single valve or a double valve. The " form " shown in Figs. 
 513 and 514 is made for one valve, and it is held by a stout rod 
 with two forks or " prongs." The mode of attachment of the 
 prong a to the form 6, by the so-called half-moons c and cotters, 
 is evident from Figs. 514 and 515. When there are two valves 
 the form is made as shown by Fig. 516 or Fig. 517, and the rod, 
 now called a " sword," is attached by a central blade which passes 
 through a corresponding slot in the middle rib. 
 
 The valve itself is made of a flat piece of leather riveted 
 between two iron plates and fastened at one end (Fig. 513) by 
 spikes or bolts, or of two similar semi-circular pieces of leather 
 attached at the circumference (Fig. 516) or in the middle of the 
 form (Fig. 517). In either case there is a band of leather or 
 gutta-percha round the form which makes the bucket fit exactly 
 in the working barrel. This band is cut out in the shape of a seg- 
 ment, such as is shown in Fig. 518, and is then bent round the 
 form and kept in its place by an iron hoop or ring. Leather 
 is usually employed, and is sometimes made from buffalo hide, in 
 order to obtain great durability ; with gutta percha there is the 
 advantage of being able to utilise a worn-out band in making 
 a new one. After it has been softened in hot water and well 
 kneaded up with a little fresh gutta-percha, to supply the waste, 
 it can be rolled out in a proper mould into a band of the 
 desired shape. Richardson's composition consists largely of 
 
DRAINAGE. 
 
 449 
 
 gutta-percha, and makes a durable and economical pump-bucket. 
 The bucket is attached to the rod by a square sliding clasp and a 
 cotter. The bucket-prong, or sword, has a little projecting ridge 
 (Fig. 514) which fits into a corresponding recess in the end of the 
 rod ; when the clasp has been drawn over and the key inserted, 
 the joint is complete. The actual rod itself may be of wood or 
 
 FIG. 512. 
 
 FIG. 513. FIG. 514. 
 
 a 
 
 FIG. 515. 
 
 FIG. 516. FIG. 517. 
 
 FIG. 518. 
 
 iron, and it may either work inside the column or outside. 
 Fig. 512 shows the commoner method in this country, but both here 
 and on the other side of the Atlantic the second plan is employed. 
 Fig. 519 represents a lifting pump used in mines on the Corn- 
 stock lode.* S is the windbore or suction pipe; Y the fixed 
 clack or valve ; P the bucket, with its valve v, moving in the 
 working barrel. The rod to which it is fixed passes through the 
 
 * Hague, " Mining Industry," United States Geological Exploration of the 
 Fortieth Parallel, Washington, 1870, p. 124. 
 
 2 P 
 
4So OIIE AND STONE-MINING. 
 
 stuffing box g, and is connected to the wooden rod E. The 
 column of pipes, made of riveted sheet iron, through which the 
 water is lifted, is shown by C. Three sheet-iron cylinders 
 riveted together form one section. Each section is pro- 
 vided at both ends with a cast-iron flange, and two 
 adjacent sections are fastened together by bolts. The cast-iron 
 pieces H carry the stuffing-box, and join the column to the 
 working barrel. Figs. 520 and 521 represent the mode of attach- 
 ment of two sections, and also the manner in which the column is 
 held in the shaft. Lap-welded sheet-iron pipes may take the 
 place of the riveted pipes of the figure. 
 
 The columns of pumps in this country are generally made of 
 cast-iron pipes with flanges ; the standard length is 9 feet. The 
 joint is made by inserting a ring of sheet iron, which has been 
 wound round with coarse flannel soaked in tar, and tightening 
 the bolts. A more perfect and durable connection is obtained if 
 the flanges are properly faced and provided with a recess for an india- 
 rubber or a gutta percha washer. Pipes of sheet iron and steel have 
 the advantage of lightness, an important matter when transport 
 is expensive, and it may be hoped that pipes of rolled steel 
 made by the Mannesmann process will be available for the 
 rising mains of mine-pumps ; fewer joints will be required, and 
 the column will be lighter and less troublesome in every way. 
 
 Wooden pumps have not disappeared in countries where 
 timber is abundant and metal expensive ; the rising mains are 
 formed of trees bored along the centre. Wood is also used in 
 certain cases when the mine water is corrosive ; thus at the Parys 
 mine, Anglesey, where the water is highly cupriferous, pumps of 
 this kind have to be employed. The wooden pipes made by 
 Wyckoff & Son, of Elmira, N.Y., are bored white pine logs turned 
 outside, strengthened by a band of hoop-iron wound around spir- 
 ally, and coated with asphalt. Pipes of this description are made 
 with bores up to 1 6 inches in diameter, and are capable of resisting a 
 pressure of 160 Ibs. per square inch, or a head of water of 370 feet. 
 
 The disadvantage of the arrangement shown in Fig. 519 is 
 that if a bucket fails, whilst the stuffing-box happens to be sub- 
 merged, the " lift is lost," in other words the pump is utterly 
 useless; whilst with the ordinary system (Fig. 512), the bucket 
 can be drawn out and " geared " once more. To remedy this 
 defect, a working barrel and a clack-piece may be inserted in 
 the column ; a new rod and bucket can then be lowered into it, 
 and made to work until the water is sufficiently mastered for 
 the old bucket to be changed. 
 
 On the other hand, the stuffing-box arrangement can claim 
 the advantage of making the buckets last longer. No doubt the 
 reason of this is that the stuffing-box acts as a guide to the rod, 
 and prevents irregular friction of the bucket against the sides of 
 the working barrel. 
 
fl\ 
 
 DRAINAGE. 
 
 45 1 
 
 The force-pump used In mines, known as the 
 plunger pump (Fig. 522), consists of a solid piston 
 (plunger), working through a stuffing-box in a 
 long cylinder standing upon a special casting 
 known as the H -piece. This is so called because 
 it is made up of two parallel cylinders, like the 
 
 FIG. ij2 
 
 FIG. 519. 
 
 Fro. 
 
 two upright limbs of the letter H, which are 
 connected by a horizontal pipe, like the cro^s-bar. 
 The H -piece is often faulty from presenting a 
 path with very sudden turns; all angles should 
 be rounded off, so as to make the passage of the 
 water as easy as possible. The H-piece has a 
 valve immediately above the wind-bore or suction- 
 pipe. In the figure the wind-bore is flat-ended 
 because it is resting in a cistern. Above the 
 
452 ORE AND STONE-MINING. 
 
 H-piece comes the door-piece with another valve, and then a 
 peries of pipes, the " column," generally of cast iron, but some- 
 times, as already stated, of wrought iron. 
 
 The action is easily understood. When the plunger is moved 
 upwards, water is drawn in by the wind-bore, and when the 
 plunger descends, the bottom clack closes, the top clack opens, 
 and the water is forced up into the column. The plunger is 
 a hollow cylinder of cast iron, accurately turned outside. Usually 
 one end of a wooden rod is passed through it and wedged tightly 
 at the bottom, and the other end is attached to the main rod by 
 staples and glands, being kept at a proper distance from it by a 
 piece of timber. 
 
 The plunger pump can claim superiority over the lifting pump 
 for several reasons : it is less likely to get out of order, and, if it 
 does begin to fail, its shortcomings are more quickly perceived and 
 more easily remedied. The first advantage is almost self-evident ; 
 one need only picture the leathern rim of the bucket rubbing 
 against the sides of the working barrel, and the solid plunger 
 sliding up and down through the stuffing box, to feel convinced 
 that it is more difficult to keep the former tight than the latter. 
 Practical experience confirms this a priori reasoning. When the 
 water contains sand in suspension, the bucket wears out rapidly 
 and has to be changed at frequent intervals; consequently it 
 must be performing much of its work in an inefficient manner. 
 Incipient faults of the bucket causing but a slight diminution in 
 the quantity of water raised are likely to pass unnoticed, whereas 
 a leaky stuffing-box is at once detected. This latter defect can be 
 speedily cured by the man in charge of the pumps (pitman), who 
 has simply to take a spanner and tighten up a few nuts, whilst 
 changing a bucket of an ordinary lifting pump involves the with- 
 drawal of the whole length of rods to which it is attached, an 
 operation causing some trouble and requiring time. Lastly, the 
 efficient manner in which the plunger does its work renders it 
 suitable for higher lifts than the bucket. 
 
 In the majority of cases a drawing lift is fixed at the bottom, 
 because it can be lengthened as the shaft is deepened, a process 
 going on continually in vein-mining, and further because it can 
 be worked with less fear of a complete break-down than a plunger, 
 if the water rises in the mine and submerges the working 
 parts. This bottom pump lifts the water into a cistern in which 
 stands the wind-bore of the plunger pump (Fig. 522), and the 
 remainder of the pumping is done in stages. The first plunger 
 .forces the water up a column into another cistern, some 60 or 
 more yards higher, where a second plunger continues the work 
 and raises the water into a third cistern, and so on until it 
 reaches the surface or the adit. 
 
 Pumping is usually done in stages because it is not always 
 easy to keep the joints tight when the pressure of the water is 
 
DRAINAGE. 453 
 
 very great. The difficulty is nowadays far less than it was for- 
 merly, and columns are made even as much as 600 metres (656 
 yards) in height vertically. 
 
 The subject of pumps would not be complete without a few 
 words upon valves. The common leather clacks used in some 
 buckets have already been briefly mentioned. The valves of 
 pumps may be divided into two classes viz., clacks and metal 
 valves. 
 
 Figs. 523 and 524 represent a simple valve called the Hake's 
 mouth valve. It consists of the seat, slightly conical below so as 
 to fit into the proper recess in a casting, such as the H -piece or 
 clack-piece, and the moving flap made of a piece of strong leather 
 between two plates of iron, held firmly together by copper rivets. 
 The flap is attached to the " tail " of the seat by bolts, and the 
 pliable leather not only makes the hinge, but ensures a water-tight 
 contact. 
 
 FIG. 523. FIG. 525. 
 
 FIG. 52 j. FIG. 526. 
 
 In the butterfly valve (Figs. 525 and 526) there are two semi- 
 circular lids or flaps. In a clack known as " Jan Ham's clack,'* 
 the two lids are hinged on the outside and look towards each other 
 instead of from one another. 
 
 A valve which has given great satisfaction in Cornwall is 
 known as Trelease's valve (Figs. 5 2 7 and 528). Its peculiarity is the 
 great freedom of motion given to it by its hinge. The seat has 
 two upright " risers " with slots in which the pin of the clack can 
 move up and down. The valve is of metal with a sheet of leather 
 I riveted on for making it water-tight. It will be readily under- 
 stood that, as the leather is not playing the part of a hinge, a 
 valve of this description will last longer than those described 
 previously ; it can also be used with a bucket. 
 
 If the water is corrosive, as too frequently happens in mines, 
 the seat and the valve are made of brass, gun-metal, or bronze, 
 and a recess is made in the circumference of the seat for the 
 insertion of wood, which will last longer for the " beat " than 
 metal. 
 
 Teague's noiseless valve (Figs. 529 to 531) is made by inserting 
 
454 
 
 ORE AND STONE-MINING. 
 
 FIG. 529. 
 
 a small valve into the flap of a Hake's mouth valve. It is said to 
 remove entirely the concussion met with in large pumps. 
 
 Among the metallic valves the most important is the double- 
 beat valve, the object of which is to afford as 
 great a waterway as possible with a small rise 
 of the valve. A double- beat valve may be briefly 
 described as a bell with a large hole at the top, 
 and surfaces of contact at top and bottom ; when 
 the bell is raised by the pressure underneath, 
 there are two passages by which the water can 
 escape, one sideways, all round the bottom, and 
 one upwards, through the top. It was invented 
 originally for steam engines, and long after- 
 wards was applied to pumps. The valve 
 shown in Figs. 532 to 534 consists of a shell a 
 connected to a ring i by radial arms c. The 
 letters b indicate strengthening ribs on the out- 
 
 3cT\ side of the shell ; they are inclined a little so 
 
 o ojo is that the stream of water passing through the 
 ^ valve may cause it to turn slightly each time it 
 
 is opened, and beat in a different position. This 
 ensures even wear and keeps the valve water-tight. 
 The two " beats," that is to say the two surfaces of contact, marked 
 n and m, are rings of white metal, gutta-percha, or india-rubber fitted 
 in grooves in the two seats q and I] r is a guide for the central 
 ring i which is bushed with brass, indicated by the black line ; 
 o and p are radial arms on which slides the brass bushing of the 
 lower ring of the shell, and they are stayed by the cylindrical piece 
 
 FIG. 530. 
 
 FIG. 531. 
 
 FIG. 532. 
 
 FIG. 574. 
 
 s and the ring I. The rise of the valve is limited byj, which is kept 
 in its place by the screw e, held by a nut in the cross-bar d ; h U 
 is the chamber in which the valve works. Fig. 533 shows the valve 
 open, and Fig. 534 is an elevation of the valve and lower seat, 
 which will greatly assist in making its mode of action plain. 
 
 The number of beats is sometimes increased to three or four. 
 
 Bittinger Pump. The Rittinger pump is an important 
 variety which has been introduced on the Continent,. for reme- 
 dying one of the defects of the ordinary pumping plant viz., 
 
DRAINAGE. 455 
 
 its intermittent action. The Cornish engine makes a sudden 
 start, the "outdoor" end of the beam goes up, and with it 
 the main rod and the plungers; then comes a pause, and all 
 this time no useful work of raising water is being done. Lastly, 
 the beam and the main rod slowly descend and the plungers 
 force up water. The actual work of pumping proper is accom- 
 plished in a short part of the time occupied by a double stroke. 
 It is evident that a smaller engine doing work continuously 
 would be just as effective as the large one acting at intervals. 
 
 The Rittinger pump (Figs. 535 and 536) may be described briefly 
 as a differential pump, with two hollow plungers, one fixed and 
 the other moving, A B is the moving part of the pump, consisting 
 of the air-chamber and plunger case A, the hollow plunger B, 
 and the quadruple-beat valve C. It is drawn up and down by the 
 side rods D D. E is the top of a lower section of the rising 
 main, and F a large pipe constituting a cistern. G is a valve 
 at the bottom of the plunger case H. At the top there is the 
 second hollow plunger I, which is fixed, working through a 
 stuffing-box in A, and K is the rising main; L is the space 
 for air. 
 
 When the moving part A B ascends C closes, and water is drawn 
 up into I and K ; at the same time G opens, and water makes its 
 way through it into H. When A B descends the space above G is 
 diminished, C rises, and water flows into A. The descent of A B 
 increases the space above the valve C, but as the plunger B is 
 larger than the plunger I, more water flows into A than it can 
 accommodate ; consequently some of it must ascend through K. 
 The amount so passing will depend upon the relative diameters 
 of the two plungers. In considering the quantity pumped during 
 each stroke, it must be observed that the two hollow plungers 
 displace just as much as if they were solid, because they are 
 always filled with water ; therefore the effective area of each is : 
 
 /outside diamete 
 - 
 
 \ 2 
 
 Let P and p represent these areas of the large and the small 
 plunger respectively and L the length of the stroke. When A B 
 makes its up-stroke, a quantity of water equal to L p is drawn up 
 into K ; during the down-stroke the amount rising into K is equal 
 to the difference of the volumes displaced by the two plungers 
 viz., L P-Ljt? or L (P-p). If it is desired that the delivery 
 shall be the same at each stroke, whether up or down, we must 
 make 
 
 Lp = L(P-p). 
 From this we get, 
 
 2L2J - LP. 
 
45 6 ORE AND STONE-MINING. 
 
 In other words, the area of the section of the small plunger must be 
 FIG. 535. FIG. 536. 
 
 one-half that of the large one. This is carried out in practice ; in 
 one of the large pumps at Mansfeld the diameter of the large 
 
DRAINAGE. 457 
 
 plunger is 0*90 m. (2ft. ii^in.), and that of the small one 
 0^64 m. (zft. i in.). The areas are therefore 0*63 sq. m. and 
 o'32 sq. m. 
 
 It is possible to dispense with the main rod altogether by 
 interposing the rising main between the two plungers, one being 
 placed at the bottom of the shaft and the other at the top ; but 
 this plan does not meet with general approval, because, although 
 it saves the cost of a main rod, it subjects a long column of pipes 
 alternately to tension and compression, with the result of trouble 
 from leakages. 
 
 (d) Accessory Arrangements : Counterbalances, Catches, 
 &c. 
 
 Counterbalances. The weight of the main rod, with its 
 strapping plates or other connections, is generally greater than is 
 required for the purpose of forcing up the column of water in 
 the pumps, and overcoming the friction of the various parts of the 
 
 FIG. 537. 
 
 Scale of Feet 
 
 O 2 / 6 8 IO T2 14 16 
 
 machinery. It becomes necessary, therefore, both in order to 
 avoid useless waste of power in lifting the main rod, and to prevent 
 its descending with too great a speed, to counterbalance so much of 
 the weight as is not actually employed in doing useful work. The 
 commonest form of counterbalance is a " bob n such as shown in 
 -Fig. 537- It is a beam d d working upon pivots (gudgeons) k, which 
 lie in brasses ; the end e, called the nose of the bob, is attached to 
 the main rod by a long connecting rod, whilst g is a box which 
 is filled, or partly filled, with old iron or stones. The beam is 
 stiffened by the upright " king post " a, and the straps b c ; //// 
 are staples and glands fastening the casting m to the beam, and i 
 is the " bishop's head " at the top of the " king post." Cast-iron 
 beams, precisely like the beams of an engine, fulfil the same office 
 at some mines, and the counterbalance is a huge piece of cast-iron 
 (Fig. 544). There is usually a " balance bob " at the surface, and 
 others are fixed at intervals in large recesses (bob-plats) cut out 
 in the side of the shaft. 
 
 West and Darlington have, introduced the counterbalance shown 
 
ORE AND STONE-MINING. 
 
 in Fig. 538 ; a is a plunger attached to the main rod of the pump 
 by a set-otf, b is a horizontal pipe connecting the two plunger-cases, 
 e is the second plunger carrying the box /, which is weighted as 
 required ; g g are its guides. The slight losses of water are made 
 up from the pipe h, which communicates with a cistern, or, when 
 this method cannot be used, a little plunger j will draw up and 
 force in the necessary supply. Fig. 539 represents the same kind 
 of counterpoise applied to an inclined shaft. 
 
 FIG. 538. 
 
 FIG. 539. 
 
 Hydraulic counterpoises have been found to be the most 
 advantageous with the huge pumping engines of 1000 horse-power 
 at Mansfeld. Probably at no mines in the world has the question 
 of pumping on a large scale been more carefully studied than in 
 that district,* and the engineers have come to the conclusion that 
 it is advisable to make their wrought-iron rods act invariably by 
 tension and never by compression. They therefore have a weight 
 at the end of the rod, and the rod + the weight must be so 
 balanced that the machine has no work but that of raising the 
 water and overcoming the friction. 
 
 * Hammer, "Die neueren Wasserhaltungen beim Mansfelrler Kupfer- 
 schieferbergbau," Der iv. allffemeine Deutsche Bergmanmtag, in Halle, &aale, 
 1889. Feslbericht und Verhandlunyen t p. 39. 
 
DRAINAGE. 
 
 459 
 
 FIG. 540. 
 
 The special counterpoise known as the Bochkoltz regenerator 
 (Fig. 540 *) is added to some pumps for the purpose of aiding the 
 main rod on beginning its downward course, when it has not only 
 to overcome the weight of the water in the column, but also to 
 open the clacks. The regenerator has been applied on the 
 assumption that at this moment there is an excess of work, because 
 the pressure of the water on the under side of the valve is acting 
 upon a smaller area than the water on the upper side, the 
 difference being the area of the beat. Bochkoltz attaches a very 
 heavy weight to the counterpoise at the surface, at right angles 
 to the beam. If the balance beam in Fig. 537 is reversed, so 
 that the king-post hangs down- 
 wards, and if a weight is fixed to 
 the bishop's head, you have a 
 Bochkoltz regenerator. In Fig. 540 
 A is the cylinder of a Bull engine ; 
 B, the piston-rod ; C, the main 
 rod of the pumps; D, the beam; 
 E, a weighted box ; F, a weighted 
 box. 
 
 Suppose that the plunger has 
 finished its up-stroke. The Boch- 
 koltz weight now hangs like a pen- 
 dulum about to begin an oscillation, 
 and in descending under the action 
 of gravity it assists the main rod 
 in its work ; as it approaches a 
 vertical position its influence is 
 lessened, and finally it creates a 
 resistance when it has to be raised 
 again. It does good at the begin- 
 ning of the stroke by helping the 
 weight of the rods, and it does good 
 at the end of the stroke by dimin- 
 ishing the velocity gradually, and by 
 bringing the pumping machinery to a standstill without a shock. 
 The idea that there is an excess of pressure upon the clacks at 
 first is not borne out by experiments, but the regenerator has 
 the advantage of enabling the engine to be started at a higher 
 speed than would be safe without it ; the mean speed is thus 
 increased, and the engine is able to make a larger number of 
 strokes safely per minute. 
 
 The same effect as that of the Bochkoltz regenerator is 
 obtained in a very simple manner by M. Rossigneux,f who gives 
 the beam a curved bearing surface which rolls upon a plane 
 
 * Gallon, Lectures on Mining, Atlas, vol. ii., plate Ixxxii. 
 t Exposition Universclle de 1889. Notice sur la Kocieii Anonyme des 
 Iluu'dUres de Montrambcrt et de la JJcraudierc, Saint-Etienne, 1889, p. 52. ' 
 
460 
 
 ORE AND STONE-MINING. 
 
 (Figs. 541 and 542). By this device the ratio of the lengths of the 
 two arms of the beams is always varying : at the commencement 
 of the down-stroke, the weight of the main rod is acting with a 
 long leverage compared with that of the counterpoise, at the end 
 of the stroke the conditions are reversed. The excess of pressure 
 due to the length of leverage accelerates the motion at first, and 
 then, as this leverage diminishes, the weight of the counterpoise 
 becomes more and more felt and the rod is stopped gradually. 
 The same effects occur during the up-stroke of the main rod. 
 The counterpoise begins by accelerating the motion, then its 
 
 FIG. 541. 
 
 influence is less and less felt until the rod stops. Rossigneux's 
 system can be applied to any existing beam with comparatively little 
 expense ; indeed it was first adopted in the case of a Cornish 
 pumping engine, which was becoming incapable of coping with an 
 additional influx of water, owing to the deepening of the shaft. 
 The variable counterpoise rendered it possible to increase the 
 number of strokes per minute with safety, and so enabled the 
 engine to do more work. 
 
 Catches. Provision must be made for a possible breakage of 
 the main rod, which might have very disastrous results for the 
 mine. If such an accident happened without any of the ordinary 
 safeguards, the beam would come down with great force and 
 play havoc in the engine-house, whilst the main rod dropping in 
 the shaft would be sure to do damage to the pumps. 
 
DRAINAGE. 
 
 461 
 
 FIG. 543. 
 
 The indoor end of the engine-beam is therefore fitted with two 
 projecting arms of iron, which come down so as almost to touch 
 two strong beams at every stroke ; if a breakage happens, they 
 arrest the motion of the engine-beam before it has had time to do 
 any harm. 
 
 Catches are also fixed in the shaft ; they are strong beams of 
 timber c c (Fig. 543, and S, Figs. 546 to 550), 
 stretching across the shaft and resting in good 
 " hitches," with the main rod a working between 
 them. The wings b b are attached to the main rod 
 by straps with bolts (" staples and glands "), and are 
 so adjusted that the end of the wing almost touches 
 the catch at the end of each down-stroke of the rod. 
 A catch of this kind limits the possible fall of the 
 main rod to the length of the stroke. Catches 
 placed in the reverse direction are also useful in 
 supplementing the action of those placed upon the 
 beam in the engine-house. 
 
 Lastly, it must be recollected that large pumping 
 machinery requires tackle capable of dealing with 
 the heavy weights which have to be moved. High 
 shears erected at the top of the pit enable pieces 
 of main rod, often 60 feet in length, or heavy 
 H -pieces, to be raised and lowered by means of a 
 strong hempen or steel rope worked by a capstan 
 moved by men, or better by a drum driven by a 
 special steam engine. 
 
 Hammer, of Mansfeld, strongly recommends that every large 
 pumping engine should have its hydraulic press for lifting the 
 beam, when changing the brasses or making repairs, the slight 
 extra cost being amply repaid by the convenience of having such 
 an appliance always ready at hand ; a similar press for raising the 
 heavy fly-wheel, if used, is likewise desirable. 
 
 Pumping Plant. After these general considerations about 
 pumps, it will be well to take an example and show how the various 
 parts are combined in order to carry on the work of drainage. 
 The seven Figures, 544 to 550, illustrate the pumping plant at 
 Shakemantle Mine in the Forest of Dean, erected by Mr. Thomas 
 Smith, the manager, to whom I am indebted for drawings, and 
 for verbal explanations on the spot. 
 
 The shaft is oval, 22 feet 6 inches by n feet 6 inches; it is 
 " steened " or walled from top to bottom with sandstone, the stone 
 being set in ordinary mortar where the ground is dry, and in 
 hydraulic mortar where it is wet. The engine is a low-pressure 
 condensing beam engine, with a yo-inch (r8o m.) cylinder A, 
 working, with a i2-feet (3*65 m.) stroke, the heavy fly-wheel B, 
 which can be driven at as slow a speed as three revolutions a 
 minute. The main rod C is made of round wrought iron, 
 
462 
 
 ORE AND STONE-MINING. 
 
 FIG. 544. 
 
DRAINAGE. 
 
 8 inches in diameter at the top, 
 diminished gradually to 6 inches 
 at the bottom. D is a beam or 
 "bob" for counterbalancing so 
 much of their weight as is not 
 required for raising the water 
 and overcoming friction. There 
 are three plungers, each 27 
 inches (0*686 m.) in diameter, 
 arranged in a straight line with 
 the main rod; this is managed by 
 attaching the rod to a cross-head 
 E (Fig. 547) above each plunger, 
 and bringing down two rods F F, 
 one on each side of the H -piece 
 G, to a lower crosshead E' from 
 which the main rod is continued 
 in the same line as before. The 
 other parts are as follows: H, 
 plunger; I, cast-iron supporting 
 girder, resting upon cast-iron 
 shoes built into the sides of the 
 shaft ; J, cistern made of cast- 
 iron plates bolted together, with 
 the joints lined with cement, and 
 screwed down to the top of the 
 column K; L (Fig. 546), spring 
 to steady the cistern ; M, hang- 
 ing rods which have the same 
 object ; N, windbore in the cis- 
 tern ; O, windbore at the bottom 
 of the shaft ; P, the door for 
 changing the bottom valve ; Q, 
 door for changing the top valve ; 
 R, door to a butterfly valve, 
 which keeps up the water in the 
 column while the valve at Q is 
 being changed ; S, beams across 
 the shaft to catch the rod by the 
 cross-plates T in case of a break- 
 age ; U, air-chamber. 
 
 The general substitution of 
 iron for timber effects a great 
 economy of space in the shaft; 
 the fly-wheel, which prevents any 
 jerk at the beginning of a stroke, 
 the air-chambers, and the ar- 
 rangement of the plungers in the 
 
 FIG. 545. 
 
464 
 
 ORE AND STONE-MINING. 
 
 FIG. 546. 
 
 FIG. 547". 
 
DRAINAGE. 
 
 FIG. 548. 
 
 FIG. 550. 
 
 465 
 
 Fro. 549. 
 
 2 o 
 
466 OHE AND STONE-MINING. 
 
 same straight line as the rods, all aid in securing a freedom from 
 vibration and a smoothness of motion which are highly conducive 
 to good working. The result is that the dryness of the shaft and 
 the absence of noise are remarkable, considering the large quantity 
 of water lifted viz., nearly 1000 gallons (4^ cubic metres) of 
 water per minute when the engine is going at the speed of only 4 
 strokes. Some idea will be gained of the massiveness of the pit- 
 work by mentioning that the H -piece alone weighs i6J tons. 
 
 Class II. Force Pumps worked by an Engine at or 
 near the bottom of the Workings. The advantage of being 
 able to dispense with the ponderous main rod, its counterpoises, 
 catches and succession of plungers, is only too obvious, to say 
 nothing of economy in first cost and more speedy erection ; and 
 this second class of pumping machinery is being more and more 
 largely used where circumstances admit of its adoption. The 
 objection to the system is the danger of the machinery being 
 " drowned," and so rendered useless, by any unusual influx of 
 water, because a mishap of this kind would involve the erection of 
 new pumping plant for draining the mine. Where the engine is 
 at the surface, such a contingency as the drowning or partial 
 drowning of the workings is not irremediable. It was this con- 
 sideration which led the authorities at Mansfeld to have some of 
 their engines above ground ; for in that district huge cavities full 
 of water (Schlotten) may be encountered unexpectedly at any 
 moment and for a time overpower all the available pumping plant. 
 On the other hand, at Mechern^'ch, under different conditions, the 
 Cornish engines at the surface have been given up and replaced 
 with great advantage by underground machines. 
 
 Underground pumping engines are divided, according to the 
 source of power, into those worked by steam, water, compressed 
 air, electricity or by petroleum engines. 
 
 Steam. At the present day we have to deal mainly with 
 steam engines when speaking of pumping on a large scale. The 
 steam may be generated above or below ground; if the boilers are 
 placed above ground, great care has to be taken in jacketing the 
 steam pipe which comes down the shaft, in order to prevent loss 
 of heat by radiation and the consequent unprofitable expenditure 
 of fuel. 
 
 It is necessary to mention two types of engines which are most 
 commonly met with : (i) horizontal engines without fly-wheel ; (2) 
 horizontal engines with fly-wheel. The engine may be simple or 
 compound, but the latter class is naturally more in repute. 
 
 (i) In this first class comes the differential engine of Davey, 
 which has been already described in speaking of engines used at 
 the surface. Instead of working the pump by the intermediary 
 of the bob and the main rod, the plunger is attached in a line 
 with the piston-rod, and forces the water up the column. The 
 height to which such a column can be taken is governed by the 
 
DRAINAGE. 467 
 
 strength of the pipes, and the difficulties of making joints 
 sufficiently tight to resist pressures measured by hundreds of 
 pounds to the square inch. At La Louviere Mine in Belgium, 
 the column is 630 yards (576 m.) high, and probably there are 
 few much higher than this at the present day ; such a column 
 means a pressure at the bottom of 55 6 atmospheres, or 81 7 pounds 
 to the square inch. 
 
 Davey provides for the possible drowning of the lower part of a 
 mine, through an inrush or unusual influx of water, by placing 
 his main engine at a sufficient height above the bottom to render 
 it practically safe from flooding ; he lifts the water to it from 
 the bottom by means of an auxiliary pump. This latter pump is 
 worked by hydraulic power transmitted by pipes, and it will 
 perform its work efficiently even if it is drowned. 
 
 There are many of these direct-acting pumps without fly-wheels 
 in the market, such as those of Knowles, Tangye and Worthing- 
 ton, but want of space prevents my describing them. 
 
 (2) Fly-wheels are added in order to secure that smooth and 
 regular action which is so conducive to the efficiency of machinery. 
 Figs. 551 and 552 give a general idea of one of the under- 
 ground pumping engines at Mansfeld. It is a horizontal com- 
 pound engine working four plungers or rams. A is the high- 
 pressure cylinder, 2 feet nj inches (900 mm.) in diameter, B the 
 low-pressure cylinder, 3 feet 9^ inches (1*150 m.) in diameter, (J 
 is the fly-wheel, D and E are crossheads connected by the rods F 
 and G, and similarly H and I are crossheads connected by the 
 rods J and K ; L M 1ST O are the four rams, each 9! inches (0*25 m.) 
 in diameter, having the same stroke as the pistons of the en- 
 gine, 4 feet ij inches (1*250 m.). P P' and Q Q' are delivery 
 pipes leading to a main delivery pipe R, which goes to the rising 
 main in the shaft. When the engine is working at the rate of 
 30 revolutions per minute, it is calculated that it raises 1540 
 gallons (7 cubic metres) of water per minute to a total height of 
 612 feet (i86'5 m.). The specific gravity of the water is 1*2. 
 
 This type of pumping engine is likewise found satisfactory on 
 all points at Mechernich. When a Cornish engine was employed 
 the consumption of coal was 4 kil. per effective horse-power, 
 measured in water actually raised, now it is only 2 *i kil. A strong 
 door is erected outside the pump-room, which can be closed so as 
 to shut it off for some time even when the water rises considerably. 
 
 Riedler bases his system of constructing pumps upon some of 
 the same considerations as those which guided Burckhardt and 
 Weiss in improving air-compressors; he works his valves by 
 gearing, and so secures the advantage of driving his pumps at very 
 much higher speeds than are possible with valves which open and 
 close of themselves. As in the case of the air-compressor, this 
 rapidity of stroke enables a smaller machine to be employed for 
 doing a given amount of work. 
 
4 68 
 
 ORE AND STONE-MINING, 
 
 Fulsometer. The pulsometer (Fig. 553) is a form of pump 
 used at mines for heights not exceeding 70 or 80 feet, and usually 
 only for temporary purposes. The steam arriving by the pipe e 
 presses directly upon the surface of the water in a chamber te, 
 
 and drives it through an opening d and a valve into the rising 
 main. When the discharge is all but complete, the steam 
 passing with the water through d creates a disturbance and in 
 consequence is condensed ; this causes a ball-valve f at the 
 top of the adjoining chamber to pass over and shut off 
 the entry of the steam. The steam now enters the adjoining 
 
DRAINAGE. 
 
 469 
 
 chamber, and, acting as before, forces its contents up the 
 rising main. In the meantime the steam in the first 
 chamber is being condensed, and its place is taken by water 
 drawn up the suction pipe 
 c ; 6 is an air-chamber, 
 g g are the suction-valves, 
 and h h stops which arrest 
 them. The action is re- 
 peated first in one chamber 
 and then in the other, so 
 that a continuous stream 
 of water is forced up. 
 
 The pulsometer will 
 pump muddy or gritty 
 water, it occupies little 
 space, is very portable, and 
 is easily fixed; in fact, it 
 may be even hung in a 
 shaft from a chain ; it dis- 
 poses of its own exhaust 
 steam, it requires no special 
 attendant, and so long as it 
 is supplied with steam it 
 will go on working. Under 
 these circumstances it is 
 evident that the pulso- 
 meter is capable of ren- 
 dering very useful services 
 to the miner. 
 
 Water. Some success- 
 ful applications of the 
 method of working pumps underground by hydraulic power 
 transmitted from the surface have been carried out at mines in 
 Scotland and on the Comstock lode in Nevada.* A horizontal 
 engine erected at the surface (Fig. 554) works two rams d d', and 
 these force water down the two pipes E E' to the underground 
 rams D D D' D' ; g g are valves through which water is supplied 
 to the pressure-pipes from cisterns. The plungers of D I) and 
 D' D' are attached to a cross-head which carries the two pump- 
 ing plungers A and B. The ram d forces water into the two 
 power rams D, and the ram d' into the two opposite rams D'. 
 If water is being driven down by d, the cross-head C will be 
 moved towards B ; the mine-water will be forced up by its 
 
 * Joseph Moore, "On Hydraulic Machinery for Deep Mining," Tram. 
 Inst. Eiig. and Shipbuilders in Scotland, vol. xxv., 1882, p. 177. R. T. 
 Moore, "On an Improved Arrangement for Working Underground Pumps 
 by Means of Hydraulic Pressure," Trans. Min. Inxt. Scotland, vol. v., 1884, 
 p. 290. "Moore's Hydraulic Pump," Engineering, vol. xli., 1886, p. 126. 
 
470 
 
 ORE AND STONE-MINING. 
 
 plunger, and sucked up by A. At the same time the power 
 water in D' D' will be driven back a little way, ready to move 
 in the opposite direction as soon as d' makes its stroke. The 
 underground pump thus follows precisely the movement of the 
 engine at the surface ; the pressure in the transmitting pipes is 
 not less than 1000 Ibs. per square inch, and this enables small 
 pipes to be employed. The pumps may be placed as desired, and 
 the system has been used not only for permanent work, but also 
 in the case of sinking a shaft. 
 
 Compressed Air and Electricity. Pumps driven by com- 
 pressed air or electricity are very convenient in situations where 
 steam power is forbidden by the conditions of the workings, 
 such as were set forth at length in a previous chapter. The 
 
 FIG. 554. 
 
 pumps worked by electricity mostly take the form of three 
 rams, driven from a common crank shaft, fixed upon the same 
 bed-plate as the motor. The high speed of the motor is reduced 
 by gearing, so as to give the crank shaft a number of revolu- 
 tions per minute suitable for pumping. The choice between 
 compressed air or electricity will depend in many cases upon 
 what plant is in use at the mine for other purposes. If com- 
 pressed air is being generated for boring machines or haulage, 
 it is only natural to make use of it instead of putting up a 
 special engine to drive a dynamo. 
 
 Where compressed air is laid on in a mine, it is easy to employ it 
 for working a Knowles, Cameron, Tangye, or other direct-acting 
 pump ; but water may be raised in a still simpler fashion by the 
 Pohle pump, which is giving satisfaction at mines in Colorado,* 
 and in supplying factories near New York. It is merely a pipe 
 
 * E. Le Neve Foster, M.S. Notes, and Browne and Behr, "Dr. Polile's 
 Air-lift Pump," Trans. 'Technical Soc. Pac. Coast, vol. vii., Feb. 1890. 
 
DRAINAGE. 
 
 FIG, 555. 
 
 full of water with a jet of air at the bottom. A B (Fig. 555) is the 
 so-called well, a piece of ordinary wrought-iron pipe 3 inches in 
 diameter ; it is connected by a bend to the T-piece C, through the 
 bottom of which passes a piece of J-inch pipe, bringing in air at 
 a pressure varying from 30 to 70 Ibs. per square inch. The 
 water-column proper is made of 
 2-inch pipe, D E F. which turns 
 over at the top and discharges 
 into another well G. The height 
 from the bottom of C to the top 
 of the water in G is 100 f>-et, 
 but as the level of the top of the 
 water in the well A B is 50 feet 
 above C, the actual lift efffcted 
 by the air is only 50 feet. By a 
 succession of such lifts the water 
 can be raised to any desired 
 height. This pump commends 
 itself by its simplicity, by the 
 ease and cheapness with which 
 it can be constructed, and by the 
 absence of any expense for keep- 
 ing it in order. 
 
 - For some time past Messrs. 
 Evans and Veitch have been 
 raising water at Cae Coch Mine, 
 in Carnarvonshire, by the direct 
 action of compressed air. Their 
 latest purnp (Figs. 556 and 557) 
 consists of two forcing chambers 
 A and A' submerged in water, 
 each provided with an inlet valve, 
 B and B', and a discharge valve, 
 C and C', which lead into a com- 
 mon rising main D. Compressed 
 air, brought into the two cham- 
 bers alternately by the pipes E 
 and E', presses upon the surface 
 of the water and forces it up 
 the pipe F or F into D. The 
 
 compressed air is turned alternately into E or E' by the action 
 of a valve worked by the independent cylinder G, placed in any 
 convenient situation. H (Fig. 557) is a pipe bringing air from 
 the compressor to the valve-chest I, with its piston valve J. Jn 
 the position shown, E' is receiving air by the port e', whilst E 
 communicates with atmosphere through e. The valve J is moved 
 by the tappets K K 3 , which are struck by the crosshead L, 
 attached to the rod which is common to the two pistons M and N. 
 
472 
 
 ORE AND STONE -MINING. 
 
 O is the piston-valve admitting compressed air into the cylinder 
 G from the pipe P ; it is worked by the tappets K 1 K 2 . The 
 cylinder Q is full of oil, which can be drawn from one side to the 
 
 other by the piston 
 
 Fl <>. 556. N if the cock R is 
 
 open. The travel of 
 the piston in N can 
 be regulated by the 
 cock ; the more nearly 
 it is closed the slower 
 will the piston move. 
 In order to make 
 sure that the valve O 
 shall not stick partly 
 open, two sets of 
 holes, s l s 2 s s s*, are 
 provided, and when 
 the piston passes, for 
 instance, between s l 
 and s 2 , the oil can 
 make its way round 
 without going 
 through the cock ; 
 the decrease in the 
 resistance quickens 
 the stroke and makes 
 it sharp and decisive 
 at the end. 
 
 With the object of 
 economising the com- 
 pressed air, the in- 
 ventors propose in 
 some cases to take 
 the exhaust from the 
 pipes E and E' direct 
 to the compressing 
 cylinder, allow it to 
 expand behind the 
 piston and so return 
 a little of the power 
 expended in compres- 
 sing it. The two 
 
 FIG. 557. 
 
 chambers A A' 
 
 may 
 
 very well be joined together in one casting, as they are in the 
 pulsometer, and they may of course be far more deeply submerged 
 than is shown in the figure. 
 
 Duty. In accounts of pumping engines the student will often 
 meet with the expression " duty." This term means the number 
 
DRAINAGE. 473 
 
 of pounds of water raised i foot high by the consumption of 112 
 pounds of coal; as used by Watt the quantity of coal was i 
 bushel, reckoned at 94 pounds. In the early part of this century 
 much interest was evinced in Cornwall with reference to the 
 work done by the various pumping engines of the county, and 
 there was great rivalry among the engineers, who vied with each 
 other in getting the highest duty from the engines and the 
 machinery under their charge. The consequence of various im- 
 provements in engines and boilers resulted in reaching duties 
 which approached and even for short periods exceeded 100 millions. 
 
 The performance of each engine was ascertained by attaching 
 a counter to the beam, which registered the number of its 
 oscillations ; the counter was kept under lock and key and 
 examined monthly by an independent observer. The number of 
 strokes made by the engine was thus known. The work done 
 in pumping was calculated from the number and depth of the 
 various lifts, the size of the plungers and the stroke of the 
 engine, and a record was kept of the amount of coal consumed. 
 With these data the duty could be determined, and the figures 
 were published every month. Nowadays this spirit of emulation 
 among Cornish agents seems to have disappeared, few engines 
 are "reported," and the duties recorded do not as a rule exceed 
 50, 60, or 70 millions. 
 
 Though the knowledge of the duty is valuable in indicating the 
 general efficiency of the pumping plant, the mere determination 
 of this figure does not give all the information that ought to be 
 in the hands of the mining engineer, for it does not tell him 
 where he can and should make improvements. When he finds a 
 difference in the respective " duties " of two pumping engines at his 
 mine, there is nothing to tell him whether the fault of the less effec- 
 tive plant lies in the coal, the engine, the boilers, the transmitting 
 arrangements, or the pumps themselves. It is important, there- 
 fore, that the engines should be indicated, and that the indicated 
 horse-power of the engine should be compared with the actual 
 useful effect in water raised. Hammer * has found that the power 
 consumed in some cases by the mere friction of the guides in the 
 shaft is as much as 24 to 30 per cent, of the total power given out 
 by the engine. Too much importance cannot, therefore, be paid 
 to the accurate fixing of the main rod and its guides. 
 
 Slip. In calculating the delivery of a plunger it is usual to 
 make an allowance for the running back of some of the water 
 through the valve, from its not closing completely when the 
 clown-stroke commences. This is what is known as " slip," and 
 it is sometimes estimated at 20 per cent, of the actual delivery, 
 though in reality scarcely appreciable in the best pumps, f 
 
 Co-operative Pumping. Owing to the subdivision of pro- 
 
 * Op. cit., p. 45. 
 
 t Rankine, A Manual of Civil Engineering^ London, 1883, p. 735. 
 
474 ORE AND STONE-MINING. 
 
 perty in this country and want of appreciation of the importance 
 of the subject, too little attention has been paid to what may be 
 called co-operative drainage. One successful application of the 
 principle, the Halkyn Tunnel, has been mentioned, and another 
 instance deserves to be noticed, though in this case the mineral is 
 coal. The South Staffordshire Mines Drainage Com mission is a 
 corporate body constituted under sevoral Acts of Parliament,* 
 passed during the last twenty years, for the purpose of 
 facilitating the drainage of mines in parts of South Staffordshire 
 and East Worcestershire. The Commissioners have power under 
 their Acts to levy a rate of gd. for every ton of coal, slack and 
 ironstone raised within a certain district, and 3^. for every ton of 
 fireclay and limestone. In order to have some check upon the 
 statements of output made by the mine-owners, the Commissioners 
 have by their last Act obtained the right of placing inspectors 
 to report upon the quantities of minerals raised. 
 
 It is not merely by erecting pumping engines of the most 
 approved and economical types at suitable centres that the 
 Commissioners have done good work; but the results of their 
 labours in preventing surface water from finding its way do\vn 
 are well worth recording. To use their own words, " By carrying 
 out surface drainage works, such as rendering water-tight the 
 canals and streams throughout the district, draining large ponds 
 of accumulated water on the surface, diverting or enlarging such 
 watercourses as caused overflows in seasons of great rainfalls, and 
 such other works as were necessary to reduce the volume of 
 water flowing into the mines by percolation to a minimum 
 amount," they reduced "the average quantity of water which has 
 to be pumped in the Tipton di.-trict every 24 hours from 
 22,705,000 gallons in 1875 to 11,643,000 in 1882, a decrease of 
 nearly 50 per cent." When considering this remarkable and 
 very satisfactory result, the special circumstances of the district 
 must not be left out of sight. In no mining district in this 
 country are the effects of subsidence more apparent than they 
 are in places where the thick coal of South Staffordshire has been 
 worked underneath, and therefore the cracked and fissured 
 overlying strala were ready to exaggerate the evils of percolation ; 
 but at the same time this very fact rendered the application of a 
 remedy all the more difficult. 
 
 According to the Annual Export published in 1892^ 27 J 
 tons of water were raised for every ton of mineral extracted from 
 the mines, and at a cost, so far as the Commissioners' engines were 
 concerned, of 0*18 of a penny, or less than one farthing, per ton 
 of water raised. 
 
 * 36 & 37 Viet., c. 150; 41 &42 Viet, c. 81 ; 45 & 46 Viet, c 131 ; 54 & 
 55 Viet, c. 135. 
 f OuUiery Guardian, vol. Ixiv., 1892, p. 648. 
 
( 475 ) 
 
 CHAPTER X. 
 VENTILATION. 
 
 Atmosphere of mines Causes of pollution of the air in mines Natural 
 ventilation Artificial ventilation by furnaces and by machines Fans 
 Testing for fire-rlamp Determination of carbonic acid and oxygen 
 Anemometers Water-gauge Efficiency of fans Friction. 
 
 ATMOSPHERE OP MINES. The composition of the air 
 of the atmosphere is about one-fifth by volume of oxygen and 
 four-fifths of nitrogen, with a little carbonic acid gas; more 
 exactly, the standard amount of oxygen may be taken at 20-9 per 
 cent., and that of the carbonic acid gas at 0^03 to 0*04 per 
 cent. 
 
 The atmosphere of mines is subject to various influences which 
 are constantly rendering it less fit for supporting life ; not only 
 do noxious gases escape from the rocks into the underground 
 excavations, but the very agents themselves employed in the 
 execution of the work pollute the air considerably. 
 
 Gases sometimes given off in mines are : carbonic acid, marsh 
 gas, nitrogen, sulphuretted hydrogen, and the vapours of mercury 
 and volatile hydro-carbons. 
 
 Carbonic Acid is known to exude from coal, and is also met 
 with in beds and veins of other minerals. It is common, for 
 instance, in the Sicilian sulphur mines,* where it is called by the 
 miners rinchiusu. 
 
 At the lead mines of Pontgibaud, in Central France, it is so 
 abundant that special fans have to be provided for getting rid of 
 it ; very distinct issues of this gas may be observed at the Foxdale 
 lead mines in the Isle of Man.f Emanations of this gas from 
 "lochs" or "vugs" have been reported to me as occurring at 
 Great Laxey mine, in the Isle of Man, and at Pennerly and 
 Roman Gravel mines in Shropshire; however, in none of 
 these, as far as I am aware, has the issue been so strong or so 
 lasting as at Foxdale. In the Alston Moor district, according 
 to Mr. Wallace, the quantity of carbonic acid discharged both 
 
 * Baldacci, Descrizione c/eologica dell 'Jsola di Sicilia, Kome, 1886, p. 362. 
 t C. Le Neve Foster, " An Emanation of Carbonic Acid at Foxdale Mine, 
 in the Isle of Man, 1 ' Trans. R. Geol. Soc. Cornwall, vol. x., p. 175. 
 
476 ORE AND STONE-MINING. 
 
 by the veins and the enclosing rocks is occasionally very con- 
 siderable.* 
 
 Carbonic acid is thought by Blountf to exist sometimes in 
 the liquid state in minute pores or fissures of chalcopyrite, and 
 he ascribes the decrepitation of certain kinds of pyrites, when 
 heated, to its presence. No doubt such pyrites would be 
 capable of giving off the gas slowly at the ordinary temperatures 
 of mines. 
 
 The hot springs and their accompanying gases at Sulphur 
 Bank minej in California are very remarkable. An analysis 
 of the gas gave : 
 
 Carbon dioxide 89 '34 
 
 Hydrogen sulphide .... 0^23 
 
 Marsh-gas 7-94 
 
 Nitrogen 2*49 
 
 lOO'OO 
 
 Some of the emanations contained ammonia, and the tempera- 
 ture of the water escaping from cracks in one of the levels was 
 176 F. (80 C.), or more than the highest temperature observed 
 at mines on the Cornstock lode. 
 
 Marsh- gas is the main constituent of fire-damp, which is by no 
 means confined to coal mines, as some might suppose. In this 
 country it is found in small quantities in the stratified ironstone 
 of the Cleveland district, and also in the Cheshire salt mines. As 
 minute bubbles of the gas may be noticed in the brine which is 
 pumped up from bore-holes near Middlesbrough, it is probable 
 that it accompanies rock-salt in that region also. Mill Close 
 lead mine, in Derbyshire, was the scene of a disastrous explosion 
 of fire-damp, some years ago, by which five men were killed, and 
 in 1884 two men were burnt by the gas taking fire in a level at 
 Hoi way Consols Mine,|| near Holywell in Flintshire, where a fatal 
 accident had happened from an explosion fifteen years previously. 
 
 At the famous Van Mine^f in Montgomeryshire, fire-damp was 
 found at the adit, and at nearly every level below, while " tapping " 
 the lode ; in other words, while making the first drivages in it 
 The miners regard it as a sure harbinger of lead ore. 
 
 Even the tin mines of Cornwall are not entirely free from fire- 
 damp. Inflammable gas was given off by the bed of stream-tin 
 
 * The Laws which fiegulate the Deposition of Lead Ore in Veins, London, 
 1861, p. 130. 
 
 t " Decrepitations in Samples of so-called Explosive Pyrites," Jour. Chem. 
 8oc., vol. xlvii., 1885, p. 593 ; and Min. Jour. vol. lv., 1885, p. 1297. 
 
 % Becker, " Geology of the Quicksilver Deposits of the Pacific Slope," 
 Jlon. V. 8. Geol. Survey, vol. xiii., Washington, 1888, p. 258. 
 
 Report* ofH.M. Inspectors of Mines for the Year 1887, p. 316. 
 
 || Jbid., 1884, p. 204. 
 
 IF C. Le Neve Foster, " Notes on the Van Mine," Trans. 7?. GcoL /S T jc. 
 Cornwall, vol. x., p. 36. 
 
VENTILATION. 477 
 
 worked under the mud of Restronguet Creek,* near Falmoutb, in 
 1873, and three comparatively slight explosions took place at Ding 
 Dong Mine,f near Penzance, about the year 1860, on re-opening 
 a level which had long been under water ; but in this case, as in 
 some others which will be mentioned, the gas seems to have been 
 formed by the decomposition of the timber supports of the level. 
 
 Turning to the Continent, it is not surprising to meet with 
 large quantities of inflammable gas in oil-wells and in ozokerite 
 mines. The work of sinking oil-wells in Roumaniaj is much 
 impeded by emanations of marsh-gas \ artificial ventilation becomes 
 necessary when a depth of 50 feet (15 m.) is reached, and the first 
 thing the men have to do in the morning is to work the fan for 
 three hours. Even then the sinker cannot stay down more than 
 about two hours at a time, and when the bottom of the shaft is 
 approaching the oil-bearing stratum, he cannot stay more than a 
 quarter of an hour. He is always fastened to a rope, and two 
 men at the surface are constantly on the alert to draw him up at 
 once, if he makes the least sign by pulling it. The sinker is 
 sometimes quite giddy when he reaches the surface. 
 
 The conditions at the petroleum wells of Burma are still more 
 unfavourable. There is so much gas that breathing is difficult, 
 and the longest time a young and strong man can stay below 
 without becoming unconscious is 290 seconds. Often a man can 
 work only i or 2 minutes ; he can be lowered to a depth of 200 
 feet in f minute and raised in i to ij minutes; in the upper 
 parts of a well, where there is no gas or only a little, he can 
 remain below much longer. 
 
 There are probably few, if any, mines more fiery than the 
 ozokerite pits of Boryslaw. Explosions have often happened, and 
 the mines have to be worked with safety lamps. However, it is 
 likely that both here, and in the oil regions, the inflammability of 
 the atmosphere is due not only to marsh-gas, but also to 
 the vapour of volatile hydrocarbons given off by the crude 
 petroleum, which maybe seen on the floor of the workings. Mere 
 marsh-gas alone would not account for the spirituous taste of 
 the air and the slight smarting of the eyes which are noticed 
 underground. The effect of the gases is to produce all sorts of 
 hallucinations and make the men wander in their talk. 
 
 The sulphur rock of Sicily || emits fire-damp very frequently, 
 
 * Taylor, " Description of the Tin Stream Works in Restronguet Creek, 
 near Truro," Proc. Inst. Mech. Eng., 1873, p. 159. 
 
 t Higgs, "Notice of an Accumulation of Carburetted Hydrogen, or 
 ' Fire-damp,' in the Ding Dong Mine," Trans. R. Geol tioc. Cornwall, vol. ix., 
 
 P- 34- 
 
 Exposition UniverseUe de Paris en 1889 : Notice sur la Roumanie, Paris, 
 1889, p. 60. 
 
 Noetlicg, " Oil-field of Twingoung and Berne, Burma," JRec. Geol. 
 Survey India, vol. xxii., 1889, p. 98. 
 
 |j Baldacci, op. cit., p. 362. 
 
4 y8 ORE AND STONE-MINING. 
 
 and the official list of disastrous explosions shows that it is an 
 enemy not to be despised by the miner. The gas fills cavities 
 existing in the bed of mineral, and also comes out of the 
 bituminous shale of the partings ; it is called antimonio by the 
 men. 
 
 Marsh-gas accompanies salt on the Continent, as it does in 
 England ; a jet of the gas, which has been piped off from a blower 
 and now serves for illuminating purposes, may be seen constantly 
 burning in the salt mine at Bex in Switzerland. Small explo- 
 sions have taken place in the Stassfurt district. 
 
 Several men were killed by an explosion of fire-damp in a 
 tunnel in the Oxford Clay,* which was in course of being driven 
 under the Col de Cabres, on the boundary of the Departments 
 Drome and Isere in France, during the year 1887, and the gas is 
 given off in such quantities in the clay pits at Klingenberg on the 
 Main f that safety lamps have to be used by the miners. 
 
 Inflammable gas is not noticed in working the copper shale 
 itself at Mansfeld, though the large amount of bituminous matter 
 which the seam contains might make one fear it would be trouble- 
 some ; a little has been met with in driving levels in some of the 
 surrounding rocks and especially in the gypsum. 
 
 Large quantities have been observed in Silver Islet mine,! 
 Lake Superior, where several explosions occurred ; and at Duncan 
 mine, Port Arthur, upon the same lake, vugs were noticed to 
 contain hydrocarbon gas under great pressure. 
 
 Becker records emissions of inflammable gas at several of the 
 quicksilver mines in California. || Inflammable gas, probably 
 marsh-gas, caused a disastrous explosion at the Bell tunnel of the 
 New Idria Mine, and marsh-gas escapes at the ^Etna Mine. At 
 the Pho3nix Mine inflammable gas issues from cracks in the 150 
 and 3oo-foot levels, the chief component being marsh-gas, as 
 shown by the following analysis : 
 
 Carbonic anhydride . . . . 074 
 
 Marsh-gas 61*49 
 
 Nitrogen 31 -44 
 
 Oxygen 6-33 
 
 lOO'OO 
 
 Treloar ^f gives an account of an issue of inflammable gas at the 
 Morro Velhogold mine in Brazil; it took fire while the men were 
 boring a hole. 
 
 * Comptes Rendu*, Soc. Ind. Min., August 1887. 
 
 t Colliery Guardian, vol. Ivi., 1888, p. 192. 
 
 Macfarlane, "Silver Islet," Tran*. Amer. Inst. J/.Z7., vol. viii., iSSo, 
 p. 241 ; Eng. Min. Jour., vol. xxxiv., 1882, p. 322. 
 
 Trans. Amer. Inst. M.E., vol. xv., 1887, p. 673. 
 
 || " Geology of the Quicksilver Deposits of the Pacific Slope," Jtlon. U. S. 
 Geol Survey, Washington, 1888, pp. 308 and 373. 
 
 ^[ Trans. 11 Geol. 8oc. Cornwall, vol. vii. p. 345. 
 
VENTILATION. 479 
 
 Fire-damp is frequently encountered in the old workings of 
 alluvial mines in the goldfields of Victoria ; * in some instances it 
 is doubtless due to the decomposition of prop timber, as at Ding 
 Dong, and in others to the gradual alteration of driftwood or 
 organic matter in the alluvial beds themselves. A serious accident, 
 caused by a fire-damp explosion, is recorded as having injured two 
 men at the Try-again Company's mine, El Dorado, in the Beech- 
 worth Mining district.! 
 
 Nitrogen, if given off in small quantities, is likely to pass un- 
 noticed by the miner ; but it makes its presence felt occasionally. 
 Miners in Slrinesdale tunnel, near Stockport, have been troubled 
 by the escape of nitrogen from fissures in the rock. It has been 
 ascertained by analysis that the gas consists of 92 volumes of 
 nitrogen, 8 volumes of oxygen, and a trace of carbonic acid. It 
 came from openings in the roof, sides and floor, and was strong 
 enough, in one case, to put out a candle 18 inches away from the 
 fissure. The men became sick and dizzy, and their limbs were 
 semi-paralysed. On some occasions the fissures drew the candle- 
 flame in, instead of blowing gas out, suggesting a communication 
 with old workings in the neighbourhood. 
 
 The highly poisonous sulphuretted hydrogen is of frequent 
 occurrence in the Sicilian sulphur mines, where the water is 
 often saturated with it. At the 3ooo-foot level of the Corn- 
 stock J lode, the water is charged with carbonic acid and 
 sulphuretted hydrogen, and has a temperature of i7oF. 
 (7 6' 7 C.). A blower of the gas, met with in a copper mine at 
 Ducktown, Tennessee, was strong enough to drive the men awa}' 
 from their work for a time. Two bad accidents took place in sink- 
 ing a shaft at Stassf urt, through rock-salt, from sudden irruptions 
 of the gas : on one occasion eight persons, and on the other seven 
 persons, were stifled. Various fatalities are ascribed to sul- 
 phuretted hydrogen at the ozokerite mines of Boryslaw, but here 
 it is thought that the gas was generated by some process of de- 
 composition in old workings, which were " holed into ' by the 
 miners. Sulphuretted hydrogen produced in a somewhat similar 
 way is supposed to have been the cause of a death at a mine on 
 the Gympie goldfield, Queensland. || 
 
 As a natural emanation in mines, sulphurous acid is very 
 rare, but Becker has noticed a pungent gas near the 150 foot 
 level at the Redington quicksilver mine in California, which 
 he considers must contain both it and sulphuretted hydrogen.^! 
 
 * Report of the Chief Inspector of Mines, Victoria, for tlie Year 1874, Mel- 
 bourne, 1875, P- 9- 
 
 t Reports of the Mining Registrars for the Quarter ended 30^/4 September, 
 1885, Melbourne, p. 15. 
 
 J Becker, op. cit., p. 339. 
 
 Phillips, Ore Deposits, 1884, London, p. 574. 
 
 || Fryar, Gases in Mines, Brisbane, 1890, p. 8. 
 
 M Op. cit., p. 287. 
 
480 ORE AND STONE-MINING. 
 
 Sulphurous acid is generated in the underground fires of sulphur 
 mines in Sicily, and some will be formed in other cases of under- 
 ground fires, if the rock contains iron pyrites. 
 
 Small quantities of mercurial vapour are stated to be found in 
 quicksilver mines, and to be the reason of their unhealthiness ; but 
 one may also suggest that constant contact with cinnabar, inhaling 
 the dust of the mineral, and allowing some to enter the stomach 
 from eating with dirty hands, may possibly account for all the 
 symptoms observed, without having recourse to the theory that 
 the vapour is present in the atmosphere of the mine. 
 
 Artificial Pollution of the Air in Mines. The pollution 
 of the air is not due solely to gases introduced naturally from 
 the surrounding rocks ; various other causes combine to render 
 the atmosphere of the mine unfit for life, and among them may 
 be mentioned the following : 
 
 1. Kespiration of the persons and animals in the pit ; exhalations from 
 
 their skin, and emanations from excrement left underground. 
 
 2. Combustion of the lamps and candles used for lighting the working 
 
 places. 
 
 3. Absorption of oxygen by pyrites and other minerals. 
 
 4. Putrefaction of timber. 
 
 5. Explosion of gunpowder, dynamite, &c. 
 
 6. Stone dust from boring. 
 
 1,2. Dr. Angus Smith* reckons that two men working eight 
 hours, and using Ib. of candles and 1 2 ozs. of gunpowder, produce 
 25*392 cubic feet of carbonic acid at 70 F. viz., 10*32 by 
 breathing, 12*276 by candles, and 2*796 by gunpowder. 
 
 It is considered by some medical authorities that the injurious 
 effects of breathing an atmosphere polluted by the products 
 of respiration, are due more to organic matter than to the 
 small proportion of carbonic acid it contains. The quantity 
 of carbonic acid serves, however, as an index of the amount of 
 organic pollution, and when the air of a room is found to contain 
 0*06 per cent, by volume of the gas, the atmosphere is said to be 
 unhealthy. Care should be taken to prevent the men from 
 habitually using the workings as latrines, and to apply suitable 
 disinfectants if the rule has been disobeyed. 
 
 3. Where the ventilation is sluggish, the absorption of oxygen 
 by pyrites, or by ferruginous minerals passing to a higher state of 
 oxidation, is sometimes very marked. 
 
 4. More important is the foulness of the underground atmo- 
 sphere produced by the decay of the timber supports. The rapidity 
 with which timber rots underground in certain circumstances 
 has already been mentioned ; the practice of leaving the useless 
 decaying timber to infect the new pieces that are put in, turns a 
 
 * Report of the Commissioners appointed to inquire into the Condition of 
 all Mines in Great Britain to which the Provisions of the Act 23 & 24 Viet. 
 c. 151 do not apply, Appendix /?., London, 1864, p. 224. 
 
VENTILATION 481 
 
 level in some instances into a hotbed of putrescent matter, offensive 
 to the smell, and injurious to the health of the men. Steel 
 supports should be welcomed, if only for ridding mines of one 
 source of pollution of the atmosphere. One of the recommenda- 
 tions of the Ventilation Board in Victoria is that all the bark 
 should be removed from the timber before it is sent down under- 
 ground.* 
 
 5. The nature of the gases and solid residues produced in 
 blasting has been already explained in Chapter IV., and the 
 statement made by some manufacturers that their explosives 
 produce " no noxious fumes " is evidently misleading. In the 
 case of gunpowder, we have the smoke made up of fine particles of 
 carbonate and sulphide of potassium with some sulphur, whilst 
 the explosive force has been due to the formation of a number 
 of invisible gases, especially carbonic acid, carbonic oxide and 
 nitrogen, with sulphuretted hydrogen, marsh-gas and hydrogen. 
 
 Nitro-cotton should produce nothing by its explosion but 
 carbonic acid, carbonic oxide, hydrogen and nitrogen ; and nitro- 
 glycerine only carbonic acid, nitrogen, and oxygen. But when 
 imperfectly detonated the resultant gases are more noxious ; both 
 explosives generate a large proportion of nitric oxide, and carbonic 
 oxide is liberated in considerable quantity. Dynamite produces 
 the same gases as nitro-glycerine, but, in addition, it sends into 
 the atmosphere, in a very finely divided state, the 25 per cent, 
 of infusorial earth which it contains. Tonite, made from gun- 
 cotton and nitrate of barium, produces solid carbonate of 
 barium, and the quantity is estimated to be 55 per cent, of 
 its weight.*!" 
 
 More has been written of late years about the fumes of roburite 
 than about those of any other explosive, and many useful observa- 
 tions have been made concerning it. After a close examination and 
 an analysis of the fumes produced by tonite and roburite, Prof. 
 Bedson and two medical menj have come to the conclusion that 
 these two explosives are no worse for the health of the miner 
 than gunpowder. With all three explosives they found traces of 
 carbonic oxide in the air, and they recommend in consequence 
 that an interval of five minutes be allowed to elapse before the 
 men return to their working places after firing. The ore-miner, 
 in studying these conclusions, must not forget that the recommend- 
 ation is made in the case of working-places which were being swept 
 out by air-currents of noo to 5000 cubic feet per minute 
 in other words, the moral is, that if no such currents exist, a 
 longer interval should be given. No nitrobenzene was detected 
 
 * Report of the Ventilation of Mines Board, Melbourne, 1888, p. x. 
 
 t " An Investigation as to whether the Fumes produced from the Use of 
 Roburite and Tonite in Coal Mines are injurious to Health," Trans, Fed. 
 Inst. Min. Eng., vol. ii., 1891, p. 380. 
 
 I Ibidem, p. 388. 
 
 2 H 
 
482 OIIE AND STONE-MINING. 
 
 in analysing the air after firing roburite, though its odour was 
 noticed on some occasions. 
 
 6. We now, lastly, come to stone du>t, which is certainly not 
 the least noxious of the impurities of the atmosphere breathed 
 by the miner. It is formed in the process of boring holes for 
 blasting, by the ^hots themselves and by the attrition of pieces 
 of rock tumbling about during the ordinary processes of mining. 
 However, it is probable that the first cause is the one from which 
 the miner is most likely to suffer injury : when he is boring a hole 
 downwards he puts in water, which serves the double purpose of 
 facilitating his work and of preventing any dust from being 
 formed; but when he bores an "upper "by hand, water is not 
 used, and even where machine drills are employed, it is not always 
 that one sees a jet of water under pressure applied to the bore- 
 hole. The result is that the atmosphere of an "end " or other 
 working place may contain a quantity of fine particles of stone 
 in suspension, which are inhaled into the lungs, and irritate 
 the air-passages ; very probably they are the principal cause of 
 the cornp^int known as " miner's asthma " or " miner's con- 
 sumption." 
 
 Having pointed out the manner in which the atmosphere of 
 mines is constantly being deteriorated, it is necessary to explain 
 how it can be renewed, and so kept in a fit state for the workmen 
 employed underground. 
 
 NATURAL VENTILATION. Two systems of ventilation 
 are employed in mines natural and artificial, either separately 
 or combined. Under the former, currents set up by natural 
 differences of temperature change the air of the workings ; under 
 the latter, artificial means are employed to bring about the same 
 result. 
 
 The i riiciple upon which natural ventilation depends is very 
 easily ui de -stood. The temperature of the earth increases at the 
 rate of i" F. for about every 60 feet of depth, and this natural 
 heat is the mainspring in creating air-currents. Suppose a very 
 simple case, two shafts AB, CD (Fig. 558), connected by a 
 horizontal level B D. The air in the shafts and level, warmed by 
 its contact with the sides of these underground passages, gradually 
 assumes their temperature, which will be usually higher or lower 
 than that of the external atmosphere ; the problem is simply 
 that of two communicating vases. At the point D we have the 
 pressure due to the weight of the column of air CD 4- the weight 
 of the atmosphere at C. At B the pressure is due to the weight 
 of the smaller column AB + the weight of the atmosphere at A. 
 
 Draw the horizontal lines CF and AE and prolong the line of 
 the shaft AB upwards by the dotted lines. The pressure of 
 the atmosphere at F and C is the same, and therefore any 
 difference of pressure at B and D depends upon- the relative 
 weights of the columns FB arid CD ; but AB is equal to ED, so 
 
VENTILATION. 
 
 483 
 
 that the real difference depends upon the weights of the two columns 
 of air FA outside the mine and CE inside the mine. In this 
 country the external atmosphere in summer is often hotter than 
 that of the mine ; therefore the column CE will be heavier than 
 the column FA. The column CD will overcome the resistance 
 presented to it by the column AB, and create a natural current 
 going in the direction CDBA. In winter the conditions are 
 
 FIG. 558. 
 
 FIG. 559. 
 
 FIG. 560. 
 
 reversed. The cold external column FA is heavier than the 
 comparatively warm internal column CE, and the weight of the 
 entire column FB will be greater than that of the column CD. 
 The result is that the weight of the column FB will cause motion 
 in the direction ABDC. 
 
 A still simpler case is one of common occurrence in vein mining 
 (Fig. 559). Let AB be an adit driven into a hill-side. Draw 
 CD horizontal, and by the dotted lines AD indicate a column 
 of air. The pressure of the atmosphere at C and D is the same ; 
 the pressure at A is that of the column of air AD + the weight 
 of the atmosphere above the line CD, 
 whereas at B one has the same constnnt 
 weight above the line DC together with 
 the column CB. If AD is warmer than 
 BC, there will be a greater pressure at 
 B than at A, and the current will move 
 in the direction CBA ; if AD is colder 
 than BC, a condition of things happen- 
 ing in winter, the current moves in pre- 
 cisely the opposite way. 
 
 Another state of things is shown in 
 Fig. 560, in which there are two shafts 
 of unequal depth connected by an in- 
 clined passage or drift. If AE is 
 
 drawn horizontal, as before, at the level of the higher openin^ to 
 the mine, and CF parallel to it at the level of the lower opening, 
 the air in the bent tube, so to say, CDB, will exactly balance 
 that contained in the vertical shaft FB, and for motive power we 
 have to depend upon the difference in weight of the two columns 
 AF and EC, a difference depending upon their relative tempera- 
 
484 ORE AND STONE-MINING. 
 
 tures. Therefore in summer we get a current travelling in the 
 direction ABDC, whilst in winter it is reversed. 
 
 In any one of these cases, the greater the difference in tempera- 
 ture, the greater will be the velocity of the ventilating current. In 
 winter the ventilation will be more active than in summer, because 
 there will be more difference between the outside and inside tem- 
 peratures ; and, furthermore, though there are differences between 
 the day temperature and the night temperature, still the tendency 
 is always to produce a current in the same direction. In summer 
 the nights may be cold though the days are hot, and therefore 
 the difference in temperature between the air of the mine and 
 that of the surface may be acting in two opposite ways according 
 to the period of the day or night. A shaft which is drawing up, 
 or is an " upcast," during the heat of the day may have a 
 descending current, or be a " downcast," in the cool hours of the 
 night, and practically have no current at all while the outside and 
 inside temperatures are alike. 
 
 There is not only this objection to natural ventilation that it 
 may vary in direction during the course of the twenty-four hours, 
 but the still greater objection that at certain seasons of the year 
 it may be nil, because there is no difference in temperature 
 between the outside and inside air to make one column heavier 
 than the other. 
 
 The creation of a natural air-current is not due solely to the 
 difference of temperature caused by the natural warmth of the 
 rocks. The heat engendered by the respiration of the men and 
 animals, by the combustion of the candles or lamps, and, lastly, 
 by the explosives is also a factor in making the air of the mine 
 warmer than that of the surface and so setting up a current. 
 The character of the sides of the shaft itself may also play its part. 
 A shaft which has water dropping down it, either from natural 
 springs that find their way in, or from slight leaks in the pumping 
 plant, will naturally become the downcast, if the other orifice is dry. 
 
 The strength of the current may be improved, or a natural 
 draught created where none existed before, by building a chimney 
 above one of the shafts, and so producing artificially a difference of 
 level between the two outlets. The direction of the wind may also 
 turn the scale, and it is often found that a mine is better ventilated 
 with some prevailing winds than with others. As an illustration 
 of an effect of this kind, I need only refer to smoky chimneys, 
 commonly caused by the wind striking some natural or artificial 
 obstruction, which directs it downwards and makes it overcome 
 the upward draught of the fire. The result is sometimes so 
 marked that the householder can tell the direction of the wind, 
 before looking out of doors, by noticing which of his chimneys 
 is giving trouble. With some mines in which the natural current 
 has less force than that of a chimne} 7 , it is not to be wondered 
 that similar occurrences take place. 
 
VENTILATION. 485 
 
 When speaking of natural ventilation, the property of diffusion 
 requires a word of comment. This property is one by which two 
 bodies of gas placed in juxtaposition with one another gradually 
 become mixed, even if the lighter occupies the higher position. 
 The process is slow compared with the mixing that is brought 
 about by convection, but still it has some effect in causing the dis- 
 persion of noxious fumes. 
 
 In the examples of natural ventilation just given, it has been 
 assumed that the mine has two orifices ; but many workings, at 
 all events at the beginning, have only one. Let us take the three 
 typical cases of a level, a shaft, and a " rise." 
 
 Let Fig. 561 represent a level driven a short way into the 
 
 FIG. 561. 
 
 side of a hill. How is the atmosphere of the " end " renewed 
 without artificial appliances? On entering such a level after 
 blasting, the explanation becomes apparent : a current of powder 
 smoke is seen hugging the roof, whilst the lower half of the level 
 is clear. If a candle is set up on the floor, its flame is deflected 
 inwards or towards the " end." The heated gases from the ex- 
 plosive, accompanied by air warmed by breathing and the combus- 
 tion of the candles, rise as much as they can, and make their way 
 out by the upper part of the level, while their place is taken by cold 
 air from the outside. The course of the gentle current is shown 
 by the dotted lines. The same phenomenon may be observed in 
 
 FIG. 562. 
 
 a cross cut driven out from a shaft. This explains the import- 
 ance, or indeed the necessity, of keeping a level as horizontal as 
 possible if it is being ventilated naturally. Take an exaggerated 
 case, in which the men have allowed their " end " to rise consider- 
 ably, as shown in Fig. 562, so that the floor of the working place 
 is three feet above a horizontal line drawn through the top of the 
 mouth of the tunnel. Smoke and warm gases produced in the 
 " end " will rise, and, finding no means of exit, will remain in tho 
 highest part until they cool down and diffusion has had time to 
 play its part. 
 
 It might seem at first sight that a current could not be formed 
 in a shaft which does not communicate with other workings; but 
 
486 
 
 ORE AND STONE-MINING. 
 
 even when no partition of any kind has been put in, the sides 
 of the pit kept cool by trickling water may cause tlie air to form 
 descending currents, whilst in the centre there is an ascending 
 current, as shown in the diagram (Fig. 563). In an incline 
 (Fig. 564) the ascent of the warm smoke along the dry roof 
 and the influx of cold air along the floor are sometimes very 
 noticeable. 
 
 When the working place is a " rise," it is evident theoretically, 
 and still plainer practically, that the warmth of the foul gases at 
 the top tends to keep them in that position, and that the evil 
 must increase as the place gets hotter (Fig. 565). The nature of 
 the excavation prevents things from improving, and the necessity 
 for artificial ventilation is nowhere more apparent than in a 
 working place of this kind, especially if the space is confined. 
 The common statement that carbonic acid collects in the lowest 
 part of the workings is correct only in cases where the gas is 
 
 FIG. 563. 
 
 FIG 564. 
 
 FIG. 565. 
 
 LEVEL 
 
 issuing forth from the rocks and sinks down like water. Where 
 it is produced by respiration, candles, lamps, or explosives, it is 
 diffused through a warmed atmosphere, ascends with it and does 
 not separate from the other gases. The consequence is that a 
 " rise " may be found badly ventilated although the air in the 
 level below is fresh and pure. 
 
 We will suppose that by reason of the difference in level of the 
 two main orifices of the mine, a trunk ventilating current has 
 been established. The air will then take the easiest road from 
 one shaft to the other, and will not penetrate into any other parts 
 of the workings unless compelled to do so. The turning of the 
 current into any required direction is effected by putting in 
 partitions and doors. In a few cases, the partition serves to make 
 a clean and sharp line of division between two currents which 
 would to a certain extent exist naturally. Thus, we have seen 
 that when the length of a level is not great, an outward current 
 travels along its roof, and an inward current along its floor (Fig. 
 561) ; between the two there is a dead space more or less interfering 
 with both currents by making their boundaries ill-defined. If a 
 horizontal partition of planks (air-sollar) is put in (Figs. 566 and 
 
VENTILATION. 
 
 487 
 
 567), the two currents are kept perfectly distinct, and the 
 natural ventilation, aided in this way, proceeds in a much more 
 effective manner; the level can therefore be driven further 
 without having recourse to machinery for creating an artificial 
 current. 
 
 A common problem is the ventilation of the far end of a drivage, 
 AB (Fig. 568), provided with a little shaft, CD, which, in 
 winter, naturally creates a current proceeding from A to D, 
 and ascending at once to C. The desired effect may be attained 
 by putting in an air-sollar DE, which compels the air to travel 
 to the far end before it can begin its ascent ; another plan 
 consists in covering the bottom of the shaft by a platform 
 (sollar), and carrying a pipe from it all the way along the roof 
 of the level to the " end." This has, of course, the same effect 
 as the air-sollar, but, unless the pipe is large, it does not give 
 
 FIG. 566. FIG. 567. 
 
 /////////// 
 
 FIG. 568. 
 
 so much area for the current. Pipes have the advantage that 
 they are very easily put in and that they can be used again and 
 again. These methods of conducting an air current are so 
 self-evident, that I should not have mentioned them, were it 
 not fcr the fact that some mine agents appear to be ignorant of 
 these simple expedients for improving the ventilation of their 
 drivages. 
 
 Where the level is wide enough, the partition may be placed 
 vertically ; it is then called a brattice. If required for temporary 
 purposes it may be made of canvas, tarred to prevent its rotting 
 (brattice cloth). More lasting and effective partitions are con- 
 structed of plank or of brick. 
 
 Any close vertical partition in a shaft dividing it into two 
 separate compartments invariably improves matters, when the 
 ventilation ot a sinking is becoming sluggish ; some trifling differ- 
 ence in the condition of the two compartments decides which is to 
 be the upcast and which the downcast. Where it is not con- 
 venient to put in a partition, a separate air compartment may 
 be formed by fixing a large pipe against one side of the shaft 
 and taking it up 30 or 40 feet above the level of the ground 
 
488 
 
 ORE AND STONE-MINING. 
 
 (Fig. 569) ; in this manner two columns of unequal height are 
 produced with the desired effect. 
 
 If a rise is being put up, or if sfcoping is being carried on 
 without any winze, there is no difficulty in diverting a natural 
 current existing in the level below and making it serve the work- 
 ing place. All that is required is to block the passage of the 
 current along the level, and so force it to take the only road that 
 lies open to it. In Fig. 570, AB is a level, and C the top of a rise, 
 which has an open compartment at each end ; one is fitted with 
 ladders, and the other serves as a shoot, down which ore or 
 rubbish can be thrown into the level below. They are separated by 
 the thick partition of rubbish piled up^n a platform in the roof of 
 the level and confined by timber at both ends. By putting a 
 
 FIG. 569. 
 
 FIG. 570. 
 
 partition in the level, the air is made to pass up one end of the rise, 
 sweep out the foul air produced by the men, candles and explosives 
 at C, and then descend into the level once more. The partition 
 may be a wooden door closing tightly against its frame, or a 
 piece of brattice cloth hung from the roof, which is readily 
 lifted when a tram waggon has to pass underneath. In the case 
 of stopes the mode of procedure is identical, but the air current 
 has not to make such sharp turns. 
 
 The case represented in Fig. 568 is that of workings at one level. 
 In vein mining the ore is generally being excavated, or at all 
 events preliminary drivages are being made, at more than one 
 horizon. In Fig. 571 two shafts have been sunk, and two 
 drivages have been made, one below the other. It is easy to 
 understand that at an earlier stage of the working, before the 
 shafts had been sunk to E and F, and the level EF driven, 
 
VENTILATION. 
 
 489 
 
 B C 
 
 a current was set up from A to O via B and D, or from 
 O to A, according to the season of the year ; but when the level 
 EF has been driven, what is to bring the current down to E, for 
 instance, when it has the shorter and easier road direct from B to 
 D? It of ten happens 
 
 that special condi- FIG. 571. 
 
 tions in the shafts 
 themselves, to which 
 allusion has already 
 been made, would in 
 any case cause a 
 movement in the air 
 from B to E, F and 
 D, even if the two 
 columns of different 
 height did not exist 
 'above them, and in 
 that case some air 
 would find its way 
 
 down to E and F; but by putting a door at G, somewhere 
 between B and D, the main current can be forced to proceed by 
 the longer road and ventilate the lower workings. If air is 
 required for men working in the level BD, the partition, or 
 door G, is not made close ; then part of the main current takes 
 the shorter road from B to D, and part the longer road from 
 B to E, F and D. 
 
 Owing to the number of shafts which are usually sunk in 
 working veins, and differences in the level of their mouths, natural 
 currents are set up to a much greater extent than is the case in 
 
 working beds, where a 
 
 FIG. 572. couple of pits situated 
 
 close to one another and 
 at the same level have to 
 serve as the sole inlet 
 and outlet orifices. For 
 this reason natural ven- 
 tilation is often found 
 to provide a fairly suffi- 
 cient supply of air along 
 
 ^ ___ the main course of the 
 
 current, and the miner 
 
 has merely to provide for the ventilation of workings in the form 
 of a cul-de-sac, such as ends, rises, and winzes, which are at a 
 distance from this current. 
 
 A common method of procedure is to sink winzes at frequent 
 intervals ; if AB and CD (Fig. 5 7 2) represent two levels, 10 to 15 
 fathoms apart, which are being driven from A to B and C to D 
 respectively , we will suppose that a ventilating current exists as 
 
490 ORE AND STONE-MINING. 
 
 shown by the arrows. B and D are blind alleys, so to say, but 
 so long as their ends B and D are not far from the main draught, 
 they may be sufficiently ventilated by convection currents, set 
 up in the manner explained in Fig. 561. Soon, however, this 
 mode of supplying air becomes inadequate, and the miner estab- 
 lishes another communication between the two levels by a fresh 
 winze or rise JK; the current is made to take the road shown 
 by the dotted arrow, if a stopping of some kind is put into the 
 winze FE. The name " winze," sometimes written " winds," 
 suggests that the original purpose of the intermediate shaft was to 
 furnish air. In some mines winzes are sunk at fairly regular 
 intervals of 30 fathoms; of course, in selecting a place for a 
 winze, preference is given to ore-bearing parts of the vein, because 
 the cost of sinking will then be partly or wholly repaid by the 
 mineral excavated. Even when the indications at the top may not 
 warrant the assumption that ore is present in paying quantities, 
 the winze serves to prove the ground and sometimes to reveal 
 unsuspected sources of profit. Winzes may be said, then, to have 
 five useful purposes : ventilation, exploration, starting-points for 
 stoping, shoots for ore or rubbish, ladder-roads for the miners. 
 
 I have thought it advisable to devote more space to natural 
 ventilation than the coal -miner would think it deserves, because 
 it is the method by which the trunk ventilation of most vein- 
 mines is carried on at the present day, and has been carried on 
 for centuries. Nevertheless, I am fully alive to its two weak 
 points viz., want of constancy and want of strength. The miner 
 is therefore often driven to seek artificial aid in order to make 
 up for these defects. 
 
 ARTIFICIAL VENTILATION. Artificial ventilation is 
 produced either by (I.) furnaces, or (II.) machines. 
 
 I. FURNACE VENTILATION. By employing a furnace, 
 the miner can effect an artificial difference of temperature between 
 two columns of air in the mine, and so produce a current similar 
 to the natural draughts just described. 
 
 In small undertakings a fire lit at or near the bottom of the 
 upcast shaft, or contained in an iron vessel suspended in the pit, 
 suffices to create a current, when the natural ventilation is no 
 longer adequate, owing to the state of the external atmosphere. 
 From small beginnings of this kind has developed the large 
 underground furnace, which is, however, in the vast majority of 
 ca^es, cot .fined to the domain of the coal-miner, and even there is 
 being gradually replaced by fans. My description may, therefore, 
 be extremely brief. The ventilating furnace (Figs. 573, 574, 
 575) * k a huge fireplace at or near the bottom of the upcast shaft, 
 over which is led either all the air of the mine, or a part of it, 
 The air heated in this way is rendered specifically lighter, and tho 
 
 * Gallon, Lectures on Mining t vol. ii., plate Ixxxvi. 
 
VENTILATION. 
 
 49 i 
 
 weight of the column of cold air in the downcast shaft overcomes 
 that of the air in the upcast and causes it to ascend. It is pre- 
 cisely the same action as that which takes place with the usual 
 domestic fireplace in this country, the chimney playing the same 
 part as the upcast shaft. Cold air is drawn in from crevices 
 around the doors and windows, is heated by the fire, and ascends 
 the chimney. 
 
 If the air of the workings is charged with a dangerous proportion 
 of inflammable gas, it is led into the upcast shaft by a special 
 drift the dumb drift at a point where there is no danger of its 
 
 573. 
 
 FIG. 574. 
 
 taking fire. In this case the air in the shaft becomes warmed in 
 its upward passage, not only from mixing with the current coming 
 from the furnace, but also by absorbing caloric from the heated 
 sides of the pit. 
 
 II. MECHANICAL VENTILATION. The methods of 
 mechanical ventilation may be classified as follows : 
 
 (1) Water blast. 
 
 (2) Steam jet. 
 
 (3) Air pumps 
 
 (i) Reciprocating. 
 
 a. Acting by displacement. 
 
 b. ,, centrifugal force. 
 
 
 (i) The ordinary water blast is a very simple appliance : it is 
 the well-known tromp, used in some countries for blowing smiths' 
 
492 
 
 ORE AND STONE-MINING. 
 
 The fall of water is also 
 apparatus (-Fig. 576). The 
 
 FIG. 576. 
 
 forges. A stream of water falls down a pipe, entangling air 
 drawn in by lateral holes, and drops into a box or barrel with two 
 orifices ; these are so arranged that the air shall escape by one, 
 under a slight pressure, and the water from the other. The current 
 of air is carried by square pipes made of boards, or, better, by 
 cylindrical pipes made of sheet zinc, to the place where ventilation 
 is required. 
 
 applied by Williams's water-jet 
 water brought down in a pipe 
 from a reservoir, or from the 
 rising main of the column of 
 pumps, issues in the form of a 
 jet from a nozzle, and, driving 
 out the air in front of it, draws 
 in air behind. The water is let 
 off by a box with a discharge 
 designed, like that of the tromp, 
 to give a little pressure, whilst 
 the air-current proceeds through a series of pipes to the " end " 
 or other working- place. The water-blast has the merit of supply- 
 ing a stream of cool moist air which is very acceptable where 
 the working-place is dry and dusty. By reversing the apparatus 
 the current may be made to flow in the opposite direction, and 
 the "end" is then ventilated by having its foul air drawn out 
 and replaced by an inward draught along the level, instead of 
 being supplied directly with fresh air from the outside or from 
 the main ventilating current. 
 
 (2) A steam jet may be applied, like a jet of water, to create 
 an exhaust and to draw out the foul air. For instance, we will 
 suppose that during the sinking of a shaft the air-pipe in Fig. 569 
 fails to act in an adequate manner, owing to a change in the 
 atmospheric conditions. The agent desires to remedy this state 
 of affairs by some cheap and temporary expedient. If he brings 
 a pipe from the boiler of the winding engine to the upright 
 ventilating pipe, and provides it with a nozzle pointing upwards, 
 he can speedily and at small expense produce an upward 
 current by turning on steam. The steam jet drives air in front 
 of it up the pipe, and at the same time warms it slightly. The 
 exhausting effect produced in this way at the bottom of the pipe 
 is sufficient, in small sinkings, to draw out all the foul air. 
 
 A draught may be produced in an upcast shaft by a ring at 
 the bottom, from which issue a number of jets of steam. Such a 
 mode of ventilation may be useful in cases of emergency. 
 
 (3) Air Pumps. Mechanical ventilation on a large scale is 
 always effected bv some kind of air pump, and generally by one 
 which has a rotary action. 
 
 (i) Among the pumps which have a reciprocating action, the 
 ordinary air compressor must be named first, as its utility 
 
VENTILATION. 493 
 
 as a ventilating agent is great. The air escaping from boring 
 or other machines renders good service in driving out foul 
 gases generated in the workings, and there is the advantage that, 
 after blasting, a powerful stream of air can be turned on for a 
 short time so as to sweep out the noxious fumes completely. 
 Even where the ground is soft and no machine drill required, it 
 is easy to bring in air from the n ain by a line of smaller pipes, 
 and turn on a fresh current when needed. In one sense it is 
 very uneconomical to bring air to a pressure of 60 or 7olbs. 
 to the square inch for ventilating purposes only ; but where 
 compressing machinery is always at hand for working underground 
 engines, it is better to be a little wasteful of a cheap power 
 at the surface than to go to the greater expense of having a boy 
 or a man to work a fan. 
 
 In a long level driven by boring machinery, with its " end " 
 far removed from the main ventilating current, the smoke 
 produced by blasting, though driven away from the actual 
 working face, still hangs about for a time, and pollutes the 
 atmosphere which the miner has to breathe in going backwards 
 and forwards. In such cases it is best to diaw away the foul 
 gases as soon as they have been produced, and prevent their 
 mixing with the air of the level. With compressed air at 
 his command, the miner can 
 
 easily work an aspirator of FIG. 577. 
 
 some kind, such as Korting's, 
 or the somewhat similar con- 
 trivance of Mr. Teague (Fig. 
 577). The ordinary air-main 
 for bringing in the compressed 
 air working the boring ma- 
 chinery is shown at the bottom 
 
 of the level, with the piece of flexible ho?e at the end. The 
 boring machine has been removed and the air shut off from the 
 hose ; by turning another cock, it passes up the upright piece 
 of pipe and rushes out of the nozzle in a direction opposed 
 to that of the driva,ge. This has a powerful exhausting effect, 
 and the " end " can be cleared of smoke in a few minutes. 
 
 The Hartz blower (duck machine, Cornwall) (Figs. 578 and 579) 
 is an air pump of simple construction which can be made up by 
 any mine carpenter. It consists of two round or rectangular 
 boxes, one fitting inside the other, and moved up and down by 
 being connected to the main rod of the pumps ; the upper box 
 has a valve at the top, and the lower box is provided with a pipe 
 also having its valve. The lower box is partly filled with water 
 so as to make an airtight connection. With the valves arranged 
 as shown in Fig. 579, the machine will act as an exhausting 
 pump and draw out the foul air ; if the play of the valves is 
 reversed it acts as a blower. 
 
494 
 
 ORE AND STONE MINING. 
 
 Struve's ventilator is a gigantic double-acting machine of this 
 class, so constructed that it draws air from the mine during the 
 down stroke as well as during the up stroke. 
 
 (ii) a. A mong the rotary air pumps acting by displacement may 
 be mentioned Roots's ventilator, of which various sizes are made, 
 suitable to the requirements of the whole of a large mine or 
 merely to those of a single " end." 
 
 This air machine (Fig. 580) consists essentially of two similar 
 pistons upon parallel shafts, revolving in a casing, but without 
 actually touching each other or the casing. The clearance in a 
 large ventilator is under \ inch. The pistons are of such a shape 
 
 FIG. 578. FIG. 579. 
 
 
 that a definite volume of air is drawn in or forced out by each 
 half-revolution. As the pistons are always kept in pcsition by 
 gearing, there is no fear of one coming in contact with the 
 other. 
 
 (ii) b. Centrifugal Ventilators or Fans. This class includes 
 all the most important ventilators in use at the present day. 
 They are characterised by the fact that the current is produced 
 by blades or vanes fixed to a shaft, revolving at a high speed. 
 The air lying between them is whirled round and flies off tangen- 
 tially at the tips, like a stone from a sling. The space occupied by 
 this air is at once filled by supplies coming in at the centre, and 
 the process goes on continuously. The centrifugal ventilators or 
 fans are generally used as exhausters that is to say, they are 
 arranged so as to suck air out of the mine, instead of forcing it in. 
 They can claim the merit of great simplicity, and of being capable 
 of withdrawing very large volumes of air. 
 
VENTILATION. 
 
 495 
 
 Four types of fans very largely used in this country at the present 
 day are the following : Capell, Guibal, Schiele and Waddle. 
 
 The Capell fan (Figs. 581 and 582) consists of two concentric 
 cylindrical chambers, each provided with six curved vanes or 
 blades, the convex sides of which are turned in the direction of 
 the rotation. The cylindrical shell or drum, b, between the two 
 sets of vanes contains openings, or portholes, dd, allowing the air 
 to pass from the inner to the outer chambers. There is one 
 such opening between every two vanes. The air contained 
 between any two of the inner vanes, c, is thrown out by centri- 
 fugal force when the fan revolves, and passes at a high velocity 
 into the corresponding outer chamber. Here it is supposed to 
 strike against the concave vane, and give back to it the greater 
 part of the impulse received from the inner chamber. The 
 object of the inventor of this and of other fans is to discharge 
 
 FIG. 582. 
 
 the air with the least possible velocity, for velocity imparted to the 
 outgoing air means work done to no purpose, or, in other words, a 
 diminution of the useful effect of the power employed in driving. 
 The advantage claimed for the fan is that it succeeds in effect- 
 ing this object even when driven at a high speed, and that, 
 therefore, it can do a large amount of work in spite of its com- 
 paratively small diameter. The small ness of the fan of course 
 reduces its first cost. It is not only capable of withdrawing large 
 quantities of air, but also of effecting a considerable diminution 
 of pressure. 
 
 The fan mny be made with an inlet on one side only or with an 
 inlet on both sides. It runs in a spiral casing, not fitting closely, 
 which gradually gives a larger and larger outlet for the air and 
 then finally discharges it into an expanding chimney. Figs. 581 and 
 582 show a double inlet fan, a being the close vertical diaphragm 
 separating it into two parts. A special passage (fan drift) brings 
 the air from the upcast shift to the ventilator, which is set in 
 motion by a belt driven by the fly-wheel of a pair of horizontal 
 engines. 
 
 These fans are made of diameters varying from 8 to 1 5 feet ; 
 
496 
 
 ORE AND STONE-MINING. 
 
 FIG. 583. 
 
 the width of the small ones is 7 feet, that of the largest nj feet ; 
 they are driven at speeds varying from 180 revolutions per 
 minute in the case of the largest fans, to 300 in the case of the 
 smallest. Cinder these conditions the smallest fan is said to be 
 capable of passing a volume of 100,000 cubic feet of air per 
 minute, with a diminution of pressure (water-gauge} of 2\ inches, 
 whilst the large fan moves the enormous quantity of 300,000 cubic 
 feet per minute. The power required is estimated at 60 I.H.P. in 
 one case and 180 in the other. 
 
 The Guibal fan, brought to us from Belgium (Fig. 583), has 
 deservedly been a favourite for many years. It is a fan with eight 
 
 or ten straight 
 blades, which are 
 not set radially. An 
 important peculia- 
 rity, introduced by 
 Guibal and since 
 copied by others, is 
 the expanding stack 
 or chimney, which 
 gradually lessens 
 the velocity of the 
 air as it travels 
 towards the point 
 of discharge into 
 the outer atmo- 
 sphere, and the slid- 
 ing shutter, a. The 
 shutter enables the 
 opening of the fan- 
 casing into the ex- 
 panding chimney to 
 be regulated at pleasure : if this opening is too big, eddies are 
 formed and air re-enters the fan ; if, on the other hand, the opening 
 is too restricted, an unnecessary amount of force is required to 
 work the fan, and the air escapes with too great velocity. By 
 careful regulation the best possible effect is attained. 
 
 The regulating shutter has been greatly improved by Messrs. 
 Walker Brothers of Wigan, who make the opening in the form of 
 an inverted V, with the object of producing a gradual instead of a 
 sudden change as each blade passes into the enclosed part of 
 the casing. The consequence is that the amount of vibration is 
 greatly reduced and the fan rendered nearly noiseless. They 
 build their fans entirely of iron or steel. 
 
 Guibal fans are made of diameters varying from 20 to 46 feet, 
 and widths varying from 6 to 13 feet. Fans 30 feet in diameter 
 are usually driven at a speed of about sixty revolutions per 
 minute, and the large fans of 40 to 46 feet at fifty revolutions. 
 
VENTILATION. 
 
 497 
 
 The Schiele fan is somewhat like the Guibal. It has the same 
 expanding chimney, but the blades are curved and the casing is 
 not close (Fig. 584) ; besides, 
 
 the width of the blades is FIG. 584. 
 
 not the same throughout. 
 The blade is widest in the 
 middle, and then it de- 
 creases both towards the 
 centre of the fan and to- 
 wards the tips. It is a 
 small fan compared with 
 the Guibal, the diameter 
 varying from 5 to 20 feet, 
 width from i to 3 feet. 
 The speed of driving is 500 
 revolutions per minute for 
 the smallest fans and TIO per minute for the largest. The air 
 is always taken in on both sides. 
 
 We come lastly to the Waddle fan, which differs from those just 
 described by running open that is to say, it is not enclosed in any 
 external casing (Fig. 585). It is a very flat hollow truncated 
 cone, with the base closed and a central opening on the other 
 
 FIG. 585. 
 
 1 
 
 side. Originally the blades a b were curved, as shown in the figure, 
 but latterly they have been made radial ; c c are some of the 
 outer plates. The air passes in at the centre and is discharged 
 at the circumference. These fans are made with a diameter 
 of 30 to 45 feet. A recent improvement is the addition of a 
 
4 g8 ORE AND STONE-MINING. 
 
 divergent outlet in other words, the two rims projecting beyond 
 the blades are inclined outwards. The velocity of the air leaving 
 the fan is thus lowered, and less power is required for driving. 
 A Waddle fan, described by Mr. Walton Brown,* had the following 
 dimensions : 
 
 Ft. in. 
 
 Diameter to periphery of divergent outlet . 36 4 
 
 ,, of the extremities of the blades . 35 o 
 
 ,, ,, inlet ring .... 13 6 
 
 Width at outlet i i 
 
 ,, periphery of fan .... 2 2 
 
 The Waddle, like the Guibal, is a slow-running fnn, which can 
 be driven directly from the engine without the aid of belts or 
 gearing. 
 
 Professor Luptonf has designed a fan, which he calls the 
 Medium fan, in which he considers that he has brought 
 together the good points both of the large fans, such as the 
 Guibal and the Waddle, and of the small fans, such as the 
 Schiele and the Capell. It is from 15 to 25 feet in diameter. 
 
 TESTING THE QUALITY OP THE AIR. In a well- 
 regulated mine the manager should be able to determine the 
 quality and quantity of the air circulating in the workings, and 
 the efficiency, from a mechanical point of view, of the machinery 
 employed for ventilation. 
 
 A knowledge of the quality of the air is necessary for two 
 reasons : it may contain gases capable of causing accidents by 
 explosion or suffocation, or it may be polluted by gaseous and 
 other impurities likely to injure the health of the men who have 
 to breathe it. 
 
 Fire-damp. Though ore and stone miners are rarely exposed 
 to any danger from fire-damp, exceptional cases arise in which car- 
 buretted hydrogen is emitted naturally or formed artificially in 
 mines, as mentioned in the beginning of this chapter. It is therefore 
 essential that the miner should have some knowledge of the 
 means employed in testing for fire-damp, even if he is not going 
 to manage a colliery. However, the subject must be treated 
 briefly, and the student desirous of further information may 
 be referred to treatises on coal -mining. 
 
 Indications of fire-damp are afforded by the singing noise made 
 by the gas if it is issuing forth in large quantities from moist coal, 
 by its bubbling up in water, and by the cracking noise of bubbles 
 as they burst ; but its presence is commonly detected by its effect 
 upon the flame of a lamp burning oil, benzine, alcohol, or hydrogen. 
 The additional brilliancy which it imparts to a platinum wire made 
 incandescent by the passage of an electric current may also be 
 employed as a test, or the diminution in the volume of a measured 
 
 * " Waddle Patent (1890) Fan," Trans. Fed. Inst. M. E., vol. ii.. 1890- 
 91, p. 173. 
 
 f Notes on the Medium Fan, Proc. Fed. Inst. M. E., vol. i., 1890, p. 65. 
 
VENTILATION. 499 
 
 quantity of air, exposed to the action of a red-hot palladium or 
 platinum wire, causing combustion. 
 
 The lamp employed should be a safety lamp, for fear that an 
 accidental ignition of the gas should cause an explosion. A few- 
 safety lamps will be described in the next chapter. They are fed 
 with vegetable or mineral oil, or with a mixture of them. In test- 
 ing for "gas," the wick is drawn down until the yellow flame almost 
 disappears, and the lamp is held in the place where the fire-damp 
 is supposed to be present; on account of its specific lightness 
 it lodges against the roof, and it is there, if anywhere, that it 
 is most likely to be found. If fire-damp is present in suffi- 
 cient quantity, its combustion produces a pale blue "cap" (halo, 
 or aureola) around the little flame, and the greater the proportion 
 of fire-damp, the higher the cap. According to Professor 
 Galloway * 2 per cent, of fire-damp in the air will give an exceed- 
 ingly faint cap J inch high, whilst 4 per cent, gives a conical cap 
 | to | inch high. If a lamp fed with benzine is used, the phe- 
 nomena are plainer. The appearances of the flame burning 
 in mixtures of air and marsh-gas of different proportions are 
 well represented by coloured plates in a report made by Professors 
 Kreischer and Winkler,f and in the Proceedings of the Austrian 
 Fire-damp Commission. J With i per cent, of fire-damp there 
 is a faint aureola, and with 2 per cent, it is plain, conical at the 
 top and inch (10 mm.) high ; when the proportion is increased 
 to 3 per cent., there is a well-defined cap J inch (20 mm.) high. 
 By using a dead-black background, it is claimed that Ashworth's 
 modified benzoline safety -lamp will give a distinct cap J inch high 
 with J per cent, of fire-damp. 
 
 The blue non-luminous flame of alcohol enables still smaller 
 quantities of fire-damp to be made known, and the Pieler lamp || 
 
 * "On the Fire-damp Cap," Proc. South Wales List. Eng., vol. x., 1876-7, 
 p, 290. 
 
 f " Untersuchungen iiber Sicherheitslampen," Jahrb. f. d. Berg- und 
 Huttenwesen im K. /Sachsen, 1884, p. 54, and plates ii. to vi. 
 
 J Verhandlungen der Centralcomite's der osterreichischen Commission zun 
 Ermittlung der zweckmtissigsten Sicherheitsmaassregeln gegen die Explosion, 
 schlagender Wetter in Bergwerken. 3 Heft. Vienna, 1890, plates ii. and iii., 
 p. 225. 
 
 Clowes, ' On the Application of the Hydrogen Flame in an ordinary 
 Sufety-lamp to the Detection and Measurement of Fire-damp," Prcc. 
 Jloy. Soc., vol. Ii. 1892, p. 90. 
 
 || Pieler, Ueler einfache Methoden zur Unlersuchung der Grubenwetter, 
 Aix-la-Chapelle, 1883. Kreischer and Winkler, op. cit., p. 77. C. Le 
 Neve Foster, " On the Pieler Lamp for indicating small quantities of Fire- 
 damp," Trans. Geol. Soc. Manchester , vol. xvii., 1884, p. 252. Broockmann 
 ' Untersuchung der durch Sumpfgas hervorgebrachten Erscheinungen 
 der Pieler-Lampe,'' Anlagen zum Haupt-Berichte der Preussischen Schlag- 
 
 wetter Com mission, vol. i.,p. 129, vol. iii. r p. 167, and plates. Walton Brown, 
 " The Pieler Spirit-lamp as a Fire-damp Indicator," Trans. N. E. Inst. 
 M. E., vol. xxxviii., 1890, p. 177 and plates. Austrian Fire-damp 
 mission, op. cit., plate iv. 
 
500 ORE AND STONE-MINING. 
 
 is based upon this fact. It begins to indicate with $ per cent, 
 of fire-damp, and even with \ per cent, the cap or aureola is 
 2 to 2 J inches high, and clearly recognisable ; with i per cent, 
 it is nearly 4 inches high. 
 
 Chesneau * obtains a plainer and more brilliant cap by adding 
 a little nitrate of copper and an organic chloride to the alcohol, 
 and Stokes has introduced the improvement of combining a 
 detachable alcohol-reservoir with an ordinary safety-lamp, and 
 so enabling the official to test with the oil or the spirit flame at 
 pleasure. 
 
 Mallard and Le Chatelier pointed out the value of the hydrogen 
 flame as a fire-damp indicator in a report to the French Fire-damp 
 Commission, and Pieler made use of it for testing samples of mine 
 air which were brought to a laboratory at the surface. Quite 
 recently Prof. Clowes f has constructed a hydrogen lamp sufficiently 
 portable for use underground in the working places themselves. 
 The lamp is so constructed that it will burn either an illuminat- 
 ing oil or hydrogen as required. A little tube is brought up through 
 the oil reservoir, and, on turning a cock, a jet of hydrogen issues 
 forth close to the ordinary oil flame. It ignites at once, and 
 the wick of the oil flame is pulled down till it goes out ; the 
 non-luminous hydrogen flame now serves as a delicate indicator. 
 The oil flame is relighted from the hydrogen flame when the 
 testing is concluded, and the gas is then turned off. The cap 
 with j per cent, of fire-damp is f inch (17 mm.) high, and with 
 i per cent, it is | inch (22 mm.) high. The hydrogen is contained 
 in a small steel cylinder which can be attached to the lamp in the 
 form of a handle. 
 
 The combination of a very delicate testing apparatus with the 
 ordinary lamp has the advantage of enabling the oificial to do 
 his work with one lamp instead of two. 
 
 Liveing's J patent gas indicator depends upon the fact that 
 fine platinum wire, made red-hot by the passage of an electric 
 current, will glow with greater brilliancy when there is fire- 
 damp present in the atmosphere than when there is none. 
 This phenomenon is due to the heat given off by the com- 
 bustion of the fire-damp in immediate contact with the wire ; 
 and the greater the heat, the more the wire will glow. The 
 increase in brilliancy corresponding to a given percentage of fire- 
 
 * " Notes sur un nouvel indicateur de grisou ; " " Essais effectuesdans les 
 mines avec 1'indicateur de grisou de G. Chesneau ; " " Instruction pour 
 1'emploi de 1'indicateur de grisou de G. Chesneau," Ann. des Mines, Paris, 
 1892 and 1893. Comptes-rendus Soc. Ind. Min., 1894, p. 25. 
 
 t " On the Application of the Hydrogen Flame in an ordinary Safety- 
 lamp to the Detection and Measurement of Firedamp," Proc. Boy. Soc., 
 vol. li., 1892, p. 90. 
 
 Liveing, On an Instrument for the Detection and Measurement of Inftam- 
 mabfa Gas in the Atmosphere of Mines. L. Clark, Muirhead and Co., West- 
 minster, London, 1881. 
 
VENTILATION. 501 
 
 damp is measured by a small photometer, which cannot be 
 understood without a ligure. 
 
 Shaw's apparatus is based upon the principle of determining the 
 limits of inflammability of gaseous mixtures, or, in other words, 
 of ascertaining the precise degree of dilation which renders the 
 mixture just capable of being ignited. It consists of two main 
 parts, an ingenious mixing apparatus and an exploding chamber. 
 By the aid of the first, a mixture of pure air with inflammable 
 gas, or with mine air, can be prepared in any desired proportions, 
 and then driven into a cylinder, where it meets with a naked flamo. 
 If the mixture contains a sufficient proportion of inflammable gas 
 to explode, a loose stopper is blown out and strikes a bell, giving 
 an audible signal. By making a succession of experiments, the 
 exact volume of mine air required to bring a known mixture of 
 gas and air to the ignition point can be ascertained, and from this 
 the percentage of fire-damp is determined. Samples of mine air 
 can thus be tested at the surface with a considerable amount of 
 accuracy by any intelligent foreman. 
 
 Carbonic Acid. Two evils are feared from the presence of this 
 gas in the atmosphere of mines either suffocation when the pro- 
 portion is large, or injury to health when the proportion is smaller. 
 If the gas is issuing from the rocks, it settles down at the bottom 
 of the excavation in virtue of its specific gravity, and men have 
 been asphyxiated by descending into shafts or wells in which the 
 gas had accumulated without their knowledge. Where danger of 
 this kind may be apprehended for instance, in mines known to 
 be liable to emissions of carbonic acid, or in the case of old work- 
 ings that have not been recently entered, the usual test is 
 lowering a lighted candle. If the candle is found to burn 
 brightly, it is concluded that there will be no danger in making 
 the descent ; if it goes out, it is evident that the air is unfit to 
 support combustion and human life ; if it burns dimly, there is 
 need for the greatest caution. 
 
 The ore and stone miner also relies upon the candle for testing 
 the air of his working place, in cases where the proportion of 
 carbonic acid falls very far short of that required to produce suffo- 
 cation. He is apt to consider that if the candle burns freely when 
 held upright, and does not go out when moved quickly from side 
 to side, the ventilation must be good. Dr. Angus Smith states in 
 his report to Lord Kinnaird's Commission * that this is a fallacy, 
 and he considers that the candle test affords no distinct sign that 
 the air is bad, until the impurities have reached an amount beyond 
 the maximum which is consistent with good ventilation. Thus, 
 the candle affords no indication of the presence of |- per cent, of 
 carbonic acid ; if the percentage is greater than this he says that 
 men should not be allowed to work, and, to use his own words, 
 "it follows therefore that the candle, as used, is only valuable 
 * Op. cit. Appendix B. p. 254. 
 
5 02 ORE AND STONE-MINING. 
 
 when the air is so bad that no one should be allowed to remain 
 in it." 
 
 He is of opinion that the carbonic acid of dwelling rooms 
 should not be allowed to exceed 0-06 or o'oy per cent., and 
 agrees with Pettenkofer,* who lays down o'i per cent, of the gas 
 as the beginning of decidedly bad ventilation. The latter says : 
 " A series of examinations have resulted in the conviction that 
 one volume of carbonic acid in 1000 volumes of room air indicates 
 the limits which divide good from bad air. This is now generally 
 adopted and practically proved, always provided that man is the 
 only source of carbonic acid in the space in question." Other good 
 authorities f write to the same effect. 
 
 Such small percentages of carbonic acid, which are wholly 
 unrecognisable by the candle test, can be readily detected and 
 easily measured by methods which are quite within the powers of 
 an ordinary mine agent. 
 
 Angus /Smith's Process The first process is one proposed by 
 Dr. Angus Smith J in 1864 viz., shaking a known quantity of 
 lime-water with a known volume of air, and observing whether 
 there is sufficient carbonic acid in the air to neutralise the lime. 
 The only alteration I propose is the use of phenolphthalein as an 
 indicator, instead of turmeric paper or rosolic acid. 
 
 The necessary apparatus consists simply of : 
 
 1. One 8-oz. bottle and cork. 
 
 2. One 5-02. bottle and cork. 
 
 3. One bottle of lime-water with excess of lime. 
 
 4. One pipette or measure holding oz. 
 
 5. Four ^-oz. bottles corked. 
 
 6. One ^-oz. bottle containing an alcoholic solution of phenol- 
 
 phthalein. 
 
 7. One piece of india-rubber tube, about a foot long. 
 
 According to Dr. Angus Smith, lime-water is fairly constant 
 in strength, and sufficiently so for his process of air-testing. 
 After the bottle (No. 3) has been well shaken up several times 
 with the excess of lime, the solution is allowed to stand till 
 it is quite clear. J ounce of it is measured exactly, and poured 
 into the 5-ounce bottle, which is then filled up with distilled water 
 or boiled rain water. This gives a solution of one-tenth the 
 strength of the original lime-water. Add a drop or two of the 
 solution of phenolphthalein, and the lime-water at once assumes 
 
 * The Relations of the Air to the Clothes we Wear, the House we Live in, and 
 the Soil we Dwell on. Abridged and translated by Augustus Hess. London, 
 
 1873- 
 
 f Parkes and de Chaumont, " A Manual of Practical Hygiene" 6th 
 edition, London, 1883, p. 153. Meymott Tidy, " Handbook of Modern 
 Chemistry," London, 1878, p. 102. 
 
 + Op. cit. Appendix B, p. 239. C. Le Neve Foster, " On One of Dr. 
 Angus Smith's Methods of Testing Air," Trans, ftlin. Assoc. and lust. 
 Corn., vol. ii., part 2, p. 40. 
 
VENTILATION. 503 
 
 a beautiful pink colour, which remains so long as there is any 
 lime un- neutralised. This dilute lime-water is now of a 
 strength that J ounce of it will neutralise the carbonic acid in 
 an 8-ounce bottle,* if the air in it contains ^ per cent, of this gas 
 by volume. This percentage has been proposed as a standard 
 which should not be exceeded. 
 
 In order to make a test, fill the 8-ounce bottle with the air 
 of the place, by sucking out its contents with a piece of india- 
 rubber tube, of course taking special care not to breathe into 
 it afterwards ; then add J ounce of dilute lime-water, cork the 
 bottle and shake it. It the pink colour disappears, the air 
 contains more than per cent, of carbonic acid ; if the colour 
 is not discharged, the air contains less than that amount. If 
 the colour fades slowly, and does not finally vanish until after a 
 great deal of shaking, it may be assumed that the percentage of 
 carbonic acid does not greatly exceed |, whereas if the disappear- 
 ance is rapid after a few shakes, the contrary of course is the case. 
 
 It need hardly be said that the accuracy of the process depends 
 upon the precision with which the solution is measured, and for 
 this purpose a pipette, or a burette, will do better than a 
 graduated glass cup. I think it best to carry each separate -J 
 ounce of lime-water in its own bottle, and it is well to see by actual 
 measurements that ^ ounce can be poured from the little bottle, 
 for a few drops always remain behind. 
 
 However, even if all precautions are taken, the observations 
 cannot pretend to vie with Dr. Hesse's method (p. 505) in accuracy, 
 because changes of temperature and pressure alter the weight 
 of the air contained in the 8-ounce bottle. Luckily in the case 
 of mines, the two sources of error act in opposite directions, 
 and sometimes may neutralise each other, the tendency to expand, 
 owing to increased temperature, being counteracted by a greater 
 barometric pressure due to the depth of the mine. 
 
 A leather case containing an 8-ounce bottle and four half- 
 ounces of lime-water, by means of which four tests can be made, 
 measures only 7 J inches by 3^ inches by 2 inches, and is sufficiently 
 portable to be easily carried, even when climbing up " rises " or 
 " stopes." 
 
 Lunge's Apparatus. Instead of simply deciding whether or no 
 the carbonic acid exceeds the proposed standard of 0*25 per cent, by 
 volume, it may be sometimes desirable to ascertain the precise 
 amount of the impurity. This can be done by Dr. Lunge's t little 
 apparatus which I described some years ago. j The method was 
 
 * The exact size should be 8-V oz., the volume of air being ;| oz., 
 because the lime-water occupies \ oz. ; but an ordinary 8-oz. bottle is 
 near enough for the purpose. 
 
 t Zur Frntje der Ventilation, Zurich, 1877. 
 
 C. Le Neve Foster, " On Dr. Angus Smith's Method of Testing the Air 
 of Mines and Dwelling-houses,'' Ann. Rep. Min. Aasoc. Corn, and Devon 
 for 1882, p. 7. 
 
54 
 
 ORE AND STONE-MINING. 
 
 originally suggested by Dr. Angus Smith,* and his process consisted 
 in pumping the air of the working place through lime-water until 
 a known standard of milkiness or opacity of the solution was 
 attained. Bad air would cause the standard amount of opacity 
 with very few strokes of the pump, whilst good air required many. 
 I now find it convenient to use lime-water of known strength, and 
 to go on with the pumpings until the pink colour given by phenol- 
 phthalein is discharged. This method is, I consider, more 
 accurate than endeavouring to reach the proposed standard of 
 milkiness. 
 
 Dr. Lunge's apparatus consists (Fig. 586) of a No. i, or 
 i -ounce, flexible ball-syringe A, connected by a piece of india- 
 rubber tube B, with the bent glass tube D; at the point C a 
 slit about f inch long is cut in the tube with a very sharp knife. 
 
 FIG. 586. 
 
 FIG. 587. 
 
 This acts as a valve. The tube D passes very little beyond 
 the cork of the bottle E, which holds about two ounces. E is 
 a tube extending nearly to the bottom, connected by a small 
 piece of india-rubber pipe with the valve-tube G, shown on 
 a larger scale in Fig. 587. It is simply a piece of glass tube, with 
 a ring made of india-rubber tube, supporting a glass valve. The 
 top part of the valve is flat, not spherical, and it allows free 
 passage of the air when in the position shown in the figure. 
 
 If you squeeze the ball A, supposing the bottle partly full of 
 water, the valve in G rises and prevents any escape of liquid, and 
 the air rushes out at C. On allowing the ball A to expand again, 
 the slit C closes, air enters through G, and bubbles up from the 
 bottom of F into the bottle. 
 
 In order to make the bottle as portable as possible, I prefer to 
 use one piece of tube containing the valve instead of having a 
 separate valve-tube as shown ; however, this is a mere detail of 
 minor importance. 
 
 Op. cit., p. 238. 
 
VENTILATION. 505 
 
 Half an ounce of lime-water or baryta-water of known strength, 
 and coloured pink by phenol phthalein, is put into the bottle ; the 
 ball is squeezed and allowed to expand, and a definite volume of 
 air is drawn into the apparatus. A good shaking is given, and 
 continued long enough to cause the absorption of all the carbonic 
 acid by the solution. This process of squeezing the ball and 
 shaking the bottle is repeated until the pink colour is discharged, 
 and knowing the strength of the solution and the volume of air 
 passed through, it is easy to calculate the percentage of carbonic 
 acid contained in the air. 
 
 Lunge reckons that each squeeze of a No. i ball causes the entry 
 of 23 cubic centimetres of air. The " No. i " means a one-ounce 
 size; it really contains about 28 cubic centimetres, but the whole 
 of this cannot be expelled by squeezing. To save the trouble of 
 making calculations each time, a table should be drawn out once 
 for all with two columns, the first giving the number of squeezes, 
 and the second the corresponding percentages of carbonic acid. 
 
 Further details are given by Winkler,* but the form of bottle 
 shown by him, with a long projecting valve tube, is not so portable 
 as the one which I use with the valve contained in the piece of 
 tube inside the bottle. My case is not larger than a field-glass, 
 and holds all that is necessary for making six determinations 
 underground ; it is most convenient to wear it upon the belt, in 
 the same manner as the " Tscherpe-Tasche," or pouch of the 
 Saxon miner. 
 
 "Where greater accuracy is required, I recommend Hesse's 
 apparatus,t with which I have made a very large number of 
 carbonic acid determinations in the working places of mines. The 
 leather case, which contains the necessary bottles, burettes, 
 barometer and thermometer, measures 15 inches by 9^ by 5. 
 
 Oxygen. The unfitness of air for breathing is indicated not 
 only by an excess of carbonic acid, but also by a deficiency of 
 oxygen. When there is both a lack of oxygen and an undue 
 proportion of carbonic acid, it is evident that some process 
 of oxidation has been going on, such as the respiration of the 
 miners, the burning of candles or lamps, the slow combustion of 
 coal or pyrites, or, lastly, the putrefaction of timber or other 
 organic matter in the mine. All four causes may combine to 
 render the atmosphere unhealthy. 
 
 Dr. Angus Smith considers that when the proportion of oxygen 
 
 * Lehrbuch der technischen Gasanalyse, Freiberg, 1885. 
 
 f Hesse, " Anleitung zur Bestimmung der Kohlensaure in der Luft, 
 
 Bestimmung 
 
 Kohlensaure in der Luft," Ibid., vol. xxxiv., 188i, p. 361. Winkler, 
 Anleitung zur cliemischen Untersuchung der Industrie- Gase, Freiberg, 1877, 
 P- 375- Winkler, Lehrbuch der technischen Gasanalyse^ Freiberg, 
 P 67. 
 
5 o6 ORE AND STONE-MINING. 
 
 by volume has been reduced below 20*9 per cent., the atmosphere 
 is impure, and when the percentage descends below 20*6, he calls 
 it exceedingly bad. 
 
 Lindemanris Apparatus. For determining the percentage of 
 oxygen in the air of mines, the simplest apparatus is that of 
 Lindemann, which is figured and described by Winkler.* It is 
 based upon the property possessed by moist phosphorus of combining 
 with the oxygen of the air at ordinary temperatures ; if a large 
 surface of phosphorus is presented to the air, the absorption takes 
 place comparatively rapidly at temperatures between 60 and 70 F. 
 (15 to 20 C.). This apparatus, and instruments of a similar 
 class in which an alkaline solution of pyrogallic acid is used 
 as an absorbent of oxygen, are better suited for use in the 
 laboratory than for making determinations in the mine itself, 
 unless it is desired to confine the observations to one spot. 
 The box containing Lindemann's apparatus is iy| inches high by 
 i of inches wide, and 5^ inches deep, and the weight when ready 
 for use is 8 Ibs. The dimensions and weight are not prohibitive, 
 but it would not be safe to carry such a box with its glass vessel 
 of phosphorus when climbing up stopes by a chain ; and there 
 are two other important objections to its use underground : (i) it 
 is difficult to manipulate such instruments with the dirty hands 
 inevitable in mines; and (2) in each working place it would be 
 necessary to wait until the whole of the apparatus had assumed 
 the temperature of the surrounding atmosphere, because unless 
 this were done the results would be erroneous from changes of 
 volume. However, it is easy to bring up samples in suitable 
 glass bottles, and then submit them to analysis in a laboratory 
 above ground. The manipulations are not difficult, and any mine 
 agent capable of doing the delicate work required for an accurate 
 mine survey or the assay of an ore, would find no difficulty in 
 making determinations, sufficiently exact for his purpose, of 
 carbonic acid and oxygen in underground air. 
 
 When the task consists in determining the proportion of such 
 gases as sulphuretted hydrogen or the quantity of organic matter, 
 he must call in the services of the chemist. 
 
 MEASURING THE QUANTITY AND PRESSURE 
 OF THE AIR. More attention is paid by miners to measure- 
 ments of quantity than to determinations of quality. The 
 quantity of air passing through any given passage can be calcu- 
 lated by measuring its sectional area and ascertaining the speed 
 of the current. In the old days there were two rough methods 
 of estimating the velocity of an air-current: (i) by carrying 
 a candle in the hand and regulating the pace so that the flame 
 was not deflected either backwards or forwards, the rate of 
 walking was therefore precisely that of the current; (2) by 
 
 *Lchrl>uch der lecluiischen Casanalyse, Freiberg, 1885, p. 58. 
 
VENTILATION. 507 
 
 exploding a little gunpowder and observing how long the smoke 
 took to travel along a measured distance in a level. These 
 methods have been abandoned in favour of speed-measuring 
 instruments known as anemometers. 
 
 Anemometers. Two kinds may be mentioned : fan-plate type 
 and windmill type. 
 
 Dickinson's * is one of the former class ; it consists of a plate 
 of mica, hung from two fine bearings, and counterpoised so that a 
 very light breeze will deflect it from its normal vertical position. 
 The deflection is measured by a quadrant attached to the frame 
 of the fan-plate, and, instead of marking the angles, it is usual to 
 show by the graduations the velocity of the air in feet per minute. 
 The instrument is graduated by actual experiments upon a test- 
 ing machine. 
 
 In anemometers of the second type, the speed of the air- 
 current is determined by the number of revolutions of an 
 instrument provided with vanes like those of a windmill. Biram's 
 anemometer, one very commonly used, has eight or ten vanes 
 made of mica or vulcanite or aluminium, attached to arms radiating 
 from a small central wheel. The instrument is held up at arm's 
 length in the current, and by the aid of suitable gearing and dials 
 and pointers, like those of a gas-meter, it registers either the 
 number of its revolutions, or the rate in feet or metres at which 
 the air is travelling, during a short period of time, measured by 
 a watch. 
 
 As a slow current of air will not make the vanes move round, 
 from its being unable to overcome the friction of the parts, 
 the makers usually supply a certificate with each instrument 
 showing what correction must he made on this account. The 
 correction is determined by a te>ting machine, on which the 
 anemometer can be whirled round at various rates of speed ; it 
 can then be seen how far the readings of the anemometer agree 
 with the known velocity at which the whirling has been carried on. 
 Messrs. Davis and Son, of Derby, make a self- timing anemo- 
 meter which dispenses with the use cf a watch ; it is held up in 
 the current and when the vanes are considered to be revolving at 
 a constant speed, a catch is pressed ; this allows the vanes to act 
 on a pointer which indicates on a dial the velocity in feet or in 
 metres per second. 
 
 In making observations with the anemometer, it is essential 
 that an airway of uniform section be taken; levels which are 
 lined with brick arching are well adapted for the purpose. If 
 the airway is not regular, eddies will be set up interfering with 
 the accuracy of the results. A further necessary precaution is 
 taking observations in various parts of the area chosen for 
 the experiment, because the velocity is not uniform through- 
 
 * Dickinson, "On Measuring AL* in Mines," Trains. Manchester GeoL &oc., 
 vol. xiv., 1878, p. 31. 
 
508 
 
 ORE AND STONE-MINING. 
 
 out this area. The mean of the readings gives the mean velocity 
 of the current. In the instructions laid down by a committee 
 appointed by three of the British Mining Institutes,* the area at 
 which the observations are made has to be divided up by horizontal 
 and vertical strings into sixteen equal parts, and a reading of the 
 anemometer taken in each. 
 
 Water-G-auge. For calculating the efficiency of the venti- 
 lating machinery, a mere knowledge of the volume of air passed 
 through the workings does not suffice ; in addition, its pressure 
 has to be determined, or rather the difference between its 
 pressure and that of the external atmosphere. 
 
 The instrument employed for this purpose is the manometer, 
 or water-gauge. It is a glass tube bent in the form of a U , partly 
 filled with water; one leg is in communication with the outer 
 atmosphere and the other with that of the mine. Usually it is 
 placed in the engine-house of the fan, and a pipe is carried 
 from it into the fan drift. The suction of the fan causes the 
 pressure of the air in the mine to be less than that of the external 
 atmosphere, and the diminution of pressure is indicated by the 
 difference in the heights of the two columns of water in the U-tube, 
 The manner in which a water-gauge acts can 
 easily be explained to students by construct- 
 ing a model from a Woulff's bottle (Fig. 588), 
 or any other bottle or jar which will take 
 three pieces of glass tube. If the mouth is 
 applied to the piece of india rubber tube A, 
 air can be drawn through the bottle in the 
 direction indicated by the arrows. With a 
 certain degree of suction, the resistance 
 caused by the passage through the tube B 
 becomes plain, and a strong air current is 
 not produced until the external pressure is 
 decidedly greater than that inside the bottle, 
 which is indicated by the rise of the coloured 
 water in the gauge C, as shown in the figure. 
 
 In the instruments employed in mines, the difference in 
 pressure is measured by a scale which can be moved up and down 
 by a screw, so as to make the zero correspond with the level of 
 the water in the free limb. It usually varies from i to 4 
 inches. In order to prevent the water in the gauge from 
 oscillating rapidly up and down, which would happen if the 
 current were irregular, the tube connecting the two upright 
 limbs is contracted, or, what comes to the same thing, the gauge is 
 
 * Joint Committee of the North of England Institute of Mining and 
 Mechanical Engineers, Midland Institute of Mining, Civil, and Mechanical 
 Engineers, and the South Wales Institute of Engineers, " On Mechanical 
 Ventilators, 1888," "Observations to be Made, and Instructions to the 
 Engineers." Trans. N. E. Inst. M. M. Eny., vol. xxxvii , 1887-8, p. 190. 
 
VENTILATION. 509 
 
 made in the form of two chambers with a glass front and a connect- 
 ing aperture, the size of which can be regulated by a tap. This 
 is Dickinson's water-gauge,* which is a brass box 6 inches high. 
 4 inches wide, and 3 inches deep, with a partition in the middle, 
 making two chambers each 2 inches by 3 inches. A glass front 
 shows the two columns of water, and a scale, graduated into 
 inches and tenths, enables the difference in their heights to be 
 measured. 
 
 Efficiency of Ventilating Appliances. The efficiency of 
 a fan or other ventilator is calculated by comparing the work 
 which it does in drawing air through the mine, with the work done 
 by the steam in moving the piston of the engine that drives it. 
 
 The work done in moving air is reckoned from the volume 
 displaced and the pressure ; the former is ascertained by the 
 anemometer and the latter by the water-gauge. As a cubic foot 
 of water weighs 62*425 pounds, each inch indicated by the water- 
 gauge will represent pressure of one- twelfth of this amount, or 5*2 
 pounds per square foot. A depression of the water-gauge of 2 inches 
 will mean 2x5-2 or 10*4 pounds pressure per square foot. In 
 common parlance the word " depression " is understood, and 
 the miner speaks of a " water-gauge " of 2 inches, for instance, 
 meaning thereby a depression of the water-gauge. 
 
 The work done is looked upon as that of pushing a volume of 
 air through a pipe under the pressure indicated by the water- 
 gauge. Let A represent the area of the airway in square feet, V 
 the velocity of the air current in feet per minute, as measured by 
 the anemometer, W the water-gauge in inches, 5*2 pounds being 
 the weight of a column of water one inch high with an area of 
 i square foot, E the useful effect of the ventilator. 
 Then 
 
 E = (A V W x 5 2) foot-pounds per minute. 
 
 To ascertain the horse-power it is only necessary to divide by 
 33,000, and we may state : 
 
 33.000 
 Thus to take an example : 
 
 If the quantity of air in circulation, A V, is 100,000 cubic feet 
 per minute, the water-gauge 1*5 inches, the useful effect of the 
 ventilation will be : 
 
 ico,ooo x 1-5 x 5-2 = 6 R 
 33,000 
 
 The efficiency of the ventilating plant is the ratio of the horse- 
 power of the ventilation so calculated to the indicated horse- 
 power of the driving engine. 
 
 * Dickinson, op. cit., p. 12. 
 
510 ORE AND STONE-MINING. 
 
 Supposing that the indicated horse-power was found to be 45, 
 we should have the ratio of 23-63 to 45 as denoting the efficiency. 
 In other words : 
 
 Efficiency = -3 3 _ -5251 or 52-51 per cent, 
 45 
 
 Resistance caused by Friction. The amount of power 
 required to overcome the friction of the air current in passing 
 through the passages of the mine must be studied, because it is 
 an important factor in the problem of ventilation ; and unless its 
 effects are appreciated the best method of arranging the ventila- 
 tion will not be understood. 
 
 The amount of friction depends upon five conditions : 
 
 1. The length of the airway, which we may call L. 
 
 2. The perimeter of the airway, P. 
 
 3. The sectional area of the airway, A. 
 
 4. The velocity of the current, V. 
 
 5. The nature of the rubbing surface, the effect of which may be 
 
 expressed by a co-efficient C. 
 
 The friction is directly proportional to the length of the airway 
 and its perimeter; in other words, if there is twice as much 
 rubbing surface, there is twice as much friction. It is inversely 
 proportional to the sectional area of the airway that is to say, a 
 level 7 feet high and 10 feet wide will cause only one-half of the 
 friction produced in a level of the same height, but 5 feet wide. 
 Lastly, the friction increases as the square of the velocity. 
 These relations may be expressed by the general formula : 
 
 L P V 2 
 
 Resistance due to friction = C 
 
 A 
 
 It is* evident from this formula that it is desirable to shorten 
 the path of the air as far as possible; much is done in this 
 direction nowadays by " splitting " the air current that is to say, 
 dividing it into separate branches instead of causing the whole 
 of the current of the downcast shaft to travel through the entire 
 length of the workings. 
 
 With regard to the second factor, the perimeter, it may be 
 well to notice that a circular section is the one with which a given 
 length of perimeter affords the largest area. Take, for instance, 
 the case just cited of a rectangular airway, 7 feet high by 5 feet 
 wide, with a perimeter of 24 feet and an area of 35 square feet. 
 A circle having a circumference of 24 feet would have an area of 
 45-8 square feet, or 30 per cent, more than the rectangle. 
 
 Splitting has also the effect of reducing the velocity required 
 for the passage of a given quantity of air through the mine. 
 Suppose that 90,000 cubic feet are wanted per minute in order 
 to ventilate the mine ; if the mine is divided into three equal 
 and similar districts and each is ventilated separately by one- 
 
VENTILATION. 511 
 
 third of the main current, the velocity of the minor currents 
 need be only one-third of what would have been necessary if all 
 the air had had to travel by one road. Reducing the velocity 
 to one-third means, according to the formula, a diminution of the 
 resistance caused by friction to one-ninth. 
 
 The co- efficient, C, varies according to the nature of the 
 rubbing surface ; in smooth passages, such as those of levels lined 
 by an arching of brick, it will naturally be less than in the 
 irregular airways along the working face, or in an airway with 
 frames of timber, forming a succession of projecting obstacles at 
 short intervals. 
 
 FIG. 589. 
 
 SCALE 
 
 0'5 
 
 FT.I I 2 3 4. 5 6 7 8 9 FT. 
 
 If the resistance due to friction, or, in other words, the pressure 
 required to overcome it, is measured in pounds per square foot, 
 then taking L and P in feet, Y in thousands of feet per minute, 
 and A in square feet, the co-efficient C varies from 0*002 to 0*014* 
 according to the nature of the airway. 
 
 Mining engineers owe a debt of gratitude to M. Murgue t for 
 his graphic representation (Fig. 589), which illustrates the influ- 
 
 * Elwen, "An Account of Experiments on the Resistance to Air Currents 
 in Mines," and Walton Brown in the discussion. Trans. N. E. Inst. H. E. t 
 vol. xxxviii., 1888-9, P- 205-218. 
 
 | " Rechercbes Experimentales sur la Perte de Charges dans les Parcours 
 Soutenains," Bull. Soc. Ind. Min., vol. vii., 1893, p. 5 ; and translation in 
 Tram. Amer. Inst. M. H., vol. xxii., 1893-1894. 
 
5 i2 ORE AND STONE-MINING. 
 
 ence of the sides of an airway in a most striking fashion. He 
 compares three kinds of airways : one arched, A B C ; a second, 
 D E E G, in bare rock ; and a third, H I J K, lined with timber ; 
 and he shows that, with the dimensions given in the figure, all 
 three airways produce the same amount of friction, or cause the 
 same loss of " head." In other words, the arched passage ABC, 
 in spite of its small dimensions, offers no greater resistance to the 
 air current than the large timbered tunnel H I J K ; whilst you 
 may put the brick lining ABC inside a level D E F G without 
 in any way requiring additional ventilating power. He concludes 
 that it is more important to diminish the friction in the air- 
 passages than to seek for better ventilators, and that the miner 
 can lessen the resistance to air-currents not only by increasing 
 the size of his levels, but also by lining them with brick or stone 
 in place of timber, and by keeping them as straight as possible. 
 
CHAPTER XL 
 LIGHTING. 
 
 Reflected daylight Candles, candle-holders Lamps and lamp oil Wells 
 light Magnesium wire Safety lamps : Davy, Clanny, Mueseler, 
 Marsaut, Hepplewhite-Gray Locks: lead rivet, magnetic bolt, 
 Cuvelier's lock Coal gas Electricity. 
 
 MINES are usually lighted by candles, torches, lamps, gas, or 
 electricity. 
 
 In a few cases the miner does his work without artificial light. 
 In sinking oil-wells in Burma,* the quantity of explosive gas is 
 so great that no naked light can be used, and even if the work- 
 man had a safety lamp, he would be unable to stay below ground 
 long without being affected by the noxious atmosphere. He 
 therefore carries no light at all, and has his eyes bandaged up 
 before he goes down, because otherwise it would take longer for 
 his eyes to become accustomed to the semi-darkness of the bottom 
 of the pit, than the whole time he can stay below ground. 
 
 Reflected Daylight. For sinking oil-wells in Japan f 
 reflected daylight is used. A piece of yellowish translucent oil- 
 paper, about 5 feet by 3 J feet, is suspended over the well at an 
 angle of 45 and throws light down the pit. The wells are about 
 3^ feet square, and are dug to a depth of 600 to 900 feet. 
 
 In driving the Bell tunnel at the New Idria quicksilver mine, J 
 in California, there was a disastrous explosion from the igni- 
 tion of some inflammable gas, and after this occurrence the 
 tunnel was lighted by the reflection of the sun's rays. A mirror 
 was kept at the mouth of the drift at the proper angle to effect 
 this, and with a straight tunnel and in a sunny country like 
 California the device answered perfectly. 
 
 Candles. The candles used by miners are very frequently 
 the so-called " dips" that is to say, they are made by dipping a 
 wick into molten tallow and allowing it to take up grease ; the 
 process is repeated several times, until the thickness of tallow is 
 sufficient. The wick is made of c6tton, or of cotton and linen. 
 
 * Noetling, Eec. Geol. Surrey India, vol. xxii., 1889, P- 97- 
 
 f Redwood, "Petroleum and its Products," Jour. Sac. Arts, vol. xxxiv., 
 
 1886, p. 832. 
 J Becker, " Geology of the Quicksilver Deposits of the Pacific Slope," 
 
 Hon. U.S. Geol. Survey, vol. xiii., 1888, p. 308. 
 
 2 K 
 
514 ORE AND STONE-MINING. 
 
 At Snailbeacb Mine, in Shropshire, the manager stipulates that 
 the wick shall be made of three threads of cotton and three of 
 linen; this is folded, and the candle therefore has a wick of six 
 threads of cotton and six of linen. 
 
 The size of the candles is reckoned by the number that 
 go to a pound, which varies from 20 to 6. Candles of six- 
 teen to the pound are very commonly used by the miners, while 
 the agents, who want an extra amount of light for their exam- 
 inations, find it convenient to have "eights" and occasionally 
 " sixes." These candles require snuffing from time to time, 
 though I have seen snuffless dips employed in exceptional cases. 
 In hot mines special dips are necessary, for those made of 
 ordinary tallow become soft and bend down. 
 
 As a rule the British ore-miner holds his candle in a lump of 
 clay, which forms a very convenient support. It has the advan- 
 tage that the candle can be stuck up at any point where it is wanted, 
 without a moment's delay in seeking for a place to fix it ; it is also 
 readily stuck upon the hat when the miner wants to climb a ladder 
 or a chain. But the clay must be soft, well kneaded, and free from 
 stones or lumps ; from time to time it has to be moistened, and 
 care and practice are required in order to work it down properly 
 as the candle is consumed. 
 
 In the Forest of Dean many years ago, the candle was stuck 
 into a cleft stick, which was carried in the mouth. Nowadays metal 
 candle-holders are used instead, with a point which can be stuck 
 into the timber or a crevice in the rock. 
 
 The tallow candle has the disadvantage of guttering in a 
 draught and of causing a good deal of smoke, which is bad if the 
 working place is at all close. The Festiniog men guard their candles 
 against draughts, when walking to and from their work, by shades 
 made out of old meat-tins with a handle of wire. If there is 
 much water dropping down a shaft the miner can protect his 
 candle by a shield of tin-plate nailed to a piece of wood. 
 
 Grease is bad for amalgamation, and sperm candles are adopted 
 in some gold mines, as they are less objectionable than those made 
 
 of tallow. Paraffin, stearine 
 
 TIG 590. and "composite" candles may 
 
 be and are used in place of the 
 common dip; they do not 
 stand a strong draught or 
 drops of water so well as the 
 latter, but they give less smoke 
 and do not gutter so much. 
 
 Moulded candles are conve- 
 niently carried by a holder, 
 such as is seen in the United States, made of a small rod of iron 
 with one end bent into a handle and the other pointed (Fig. 590). 
 In the middle there is a cylinder of thin sheet iron which has 
 
LIGHTING. 515 
 
 spring enough to clip the candle firmly ; a sharp hook, sticking 
 
 up at right angles to the horizontal rod, enables the holder to be 
 
 hung on to the slightest little projection, if there is no convenient 
 
 crevice or piece of timber into which its point can be thrust. The 
 
 Australian has a somewhat similar holder made of wire, known as 
 
 the "spider."* The wire is about one-sixteenth of an inch thick, 
 
 twisted as shown (Fig. 591); 
 
 the spiral portion holds the FIG. 591. 
 
 candle, and the little hook will p, 
 
 hang on to the face of the 
 
 rock. 
 
 A candle-holder of some 
 kind is more convenient to an 
 official who has to make notes 
 underground, than the usual 
 lump of clay ; with the latter 
 it is difficult to keep the note- 
 book clean. 
 
 Torches. Torches are em- 
 ployed in a few exceptional 
 instances. The foremen at 
 Falun, in Sweden, carry 
 torches consisting of bundles 
 of pine sticks held together 
 by an iron ring, and some gold mines in Japan f were lighted a 
 few years ago by torches made of dried bamboo twigs ; fires of 
 pitch-wood have been used at night when washing down gravel 
 by the hydraulic process.:}: Large underground chambers may be 
 lit up for a short time, in order to examine the roof, by burning 
 a bundle of wood shavings soaked with naphtha and petroleum. 
 
 Lamps. Lamps vary much in shape and size. The Sicilian 
 miner has a lamp of the simplest construction imaginable ; it is a 
 mere open cup of unglazed pottery, about 2 inches in diameter 
 and i inch deep, with a little lip for holding a cotton wick, which 
 lies loosely in the olive oil used as an illuminant. It is ruder 
 than the old Roman lamps found at Pompeii, which somewhat 
 resemble those still employed in the Hartz. The latter are 
 provided with a hook, by which they can be held between 
 the thumb and forefinger when climbing ladders; the hook 
 has a sharp point which the miner can stick into a timber 
 prop or a crevice in the rock while at work. The body of the 
 lamp is closed ; it has a tube for the cotton wick and a hole with 
 a screw-plug through which the supply of oil can be replenished. 
 
 * Annual Report of the Secretary for Mines, Victoria, for the year 1888, 
 Melbourne, 1889, p. 36. 
 
 t Frecheville, " The Mining and Treatment of Gold Ores in the North 
 of Japan," Min. Proc. Inst. (7..Z?., vol. Ixxv., 1883-84, p. 169. 
 
 J Bowie, Hydraulic Mining in California, New York, 1885, p. 246. 
 
5 i6 ORE AND STONE-MINING. 
 
 A pricker for trimming the wick is attached by a light chain. A 
 smaller but similar lamp is met with in France, northern Italy, 
 and parts of Spain ; the body is lenticular, and is suspended by a 
 long hook. 
 
 The foremen in the Hartz mines prefer a somewhat similar lamp 
 in which they can burn tallow ; it is an open tray with a rim 
 around it and a lip for the cotton wick ; a large lump of tallow 
 lies in the lamp at the opposite side to the wick, and if the agent 
 wishes to make a flare-up, to illuminate a working place more 
 thoroughly, he need only push a good supply of tallow towards the 
 wick holder, and soon obtains the desired effect. 
 
 In the Mansfeld copper district the miner has a small tin lamp 
 which can be hung by a wire loop to a hook on the hat, if he is 
 climbing, or be placed upon the ground in the working place. It 
 has a double case, the outer one serving to catch any oil which 
 may run over from the spout-like wick-tube. 
 
 The Saxon miner still adheres to the " Blende," a wooden case 
 lined with tin-plate or brass, in which he carries a small globular 
 oil lamp. The case is useful in walking or climbing in very 
 draughty parts of the mine, and can be hung from the neck by a 
 leather strap. 
 
 In Scotland and in some parts of the United States, a small but 
 serviceable tin lamp,of the shape shown in Fig. 592,13 very common. 
 It can be hooked on to the hat when climbing 
 FIG. 592. ladders, or on to the rock. Olive oil or rape oil is 
 burnt in the lamps just described, and the miner 
 carries with him a supply in a little flask. 
 
 Lamps have the advantage of being cheaper 
 and cleaner than tallow candles, but the latter 
 do not seem likely to be displaced in English and 
 Welsh ore mines, though the Scotch lead miner 
 prefers the former. 
 
 Mineral oils are occasionally used instead of 
 vegetable oils for ordinary miners' lamps. At the underground 
 stone quarries near Bath the men employ small lamps fed by ben- 
 zoline, which is held by a sponge in the reservoir. Petroleum 
 " Hurricane" lamps for lighting up pit-bottoms and landings 
 (plats) are not uncommon, and even levels are lit up in this way 
 by hanging a lamp at each bend in the road. This saves the 
 miner the trouble of carrying a lamp, and the light is quite 
 sufficient for the purpose of tramming, even if the stretches are 
 somewhat long. 
 
 Flare lamps, similar to those used by " Cheap Jacks," which 
 generate gas from naphtha, or a mixture of naphtha and 
 petroleum, flowing into a hot burner, may occasionally be seen 
 in parts of underground slate quarries, where a good deal of light 
 is required for hooking- on and unhooking waggons. 
 
 Wells Light. Among recent inventions for illuminating, I 
 
LIGHTING. 
 
 JT IG 
 
 must specially mention the Wells light, which, after being largely 
 used for surface works, is now finding applications underground. 
 The Wells light is a contrivance for burning tar oils converted 
 into gas, when forced through a heated burner by pressure pro- 
 duced by a hand air-pump. 
 
 Fig. 593 shows the principal parts of the lamp, A is a closed 
 cylinder made of steel boiler plate, B is a pump worked by the 
 handle C, which can be used 
 for pumping in either air or 
 oil ; whilst the light is run- 
 ning, the oil is drawn from a 
 bucket by the piece of hose 
 D. E is the oil which has 
 been pumped in, thereby 
 compressing the air above it 
 to about 20 Ibs. per square 
 inch. On turning the tap G, 
 the oil is forced up the pipe 
 II to the generating tubes 
 I 1, which have been pre- 
 viously heated by lighting 
 some cotton waste and oil in 
 the tray K. The prelimi- 
 nary heating may also be 
 effected by burning a spray 
 of the oil, produced by a 
 special starting appliance 
 forming part of the lamp. 
 The oil in its passage through 
 the hot burner I is converted 
 into vapour, which issues 
 forth from the nozzle L and 
 produces a flame of 1 2 to 30 
 inches in length, with a con- 
 sumption of half a gallon to 
 ij gallons of oil per hour, 
 giving a light of 500 to 4000 
 candles. O is a plug con- 
 nected to a rod which serves 
 
 the double purpose of letting off the air quickly at any time, 
 and also of gauging the depth of the oil in the cylinder. 
 
 The lamp is easily carried about from place to place. The 
 smallest size and the larger one, No. 3, have both been employed 
 of late in the large chambers of the Festiniog slate mines for 
 examining the roof and sides, and also for plate-laying. The 
 pressure of the air in the reservoir is kept up by a few strokes of 
 the pump from time to time. 
 
 The brilliant light emitted by burning mngnesium is utilised at 
 
 -_-u-t^:.(L \\ 
 
 n s~y ~s o- o ~v~ rtf v 
 
5i8 ORE AND STONE-MINING. 
 
 Festiniog, in addition to the Wells light, for examining tho 
 underground chambers. The agents of some of the mines 
 carry a little stock of magnesium, ribbon in their pocket-books, 
 and set fire to a piece if they wish to throw a powerful light upon 
 any particular spot which may require special attention. At 
 two of the mines the metal is burnt in a special lamp. It 
 consists of a coil of magnesium ribbon about J inch wide wound 
 upon a reel, which is fed by clock-work, so that it issues 
 from a tube at the focus of a silvered mirror about 8 inches in 
 diameter. The lamp is held by a convenient handle, and the light 
 can be directed on to any given point without dazzling the eyes. 
 The ribbon is consumed at the rate of about 10 inches per minute ; 
 the lamp can be started and stopped by touching a catch which 
 controls the clock-work, and there are means of altering the speed 
 at which the ribbon is fed forwards. 
 
 Safety Lamps. The subject of safety lamps that is to say, 
 lamps which can be used in an atmosphere containing a certain 
 amount of inflammable gas without fear of causing an explosion 
 may seem out of place to some who suppose that their 
 use is confined to coal pits : but when we recollect that fire- 
 damp has been met with in mines worked for diamonds, gold, 
 iron, lead, quicksilver, salt, silver, sulphur, and tin, and 
 further that a lead mine in this country is lighted entirely 
 with such lamps, and that they are indispensable in the 
 case of ozokerite, it is evident that miners generally should 
 have some knowledge of the principles upon which they are 
 constructed, and the manner in which they are used. However, 
 in the mines with which we are dealing, safety lamps are the 
 exception, and, therefore, the subject can be dealt with in a 
 summary manner. 
 
 The construction of the safety lamp is based upon the fact 
 that gauze of a certain mesh, made with wire of a certain gauge, 
 is capable of cooling burning gases to a point below that at 
 which combustion will take place in other words, it will pre- 
 vent the passage of flame. Therefore, when a lamp enclosed in a 
 suitable cylinder of this gauze is placed in an atmosphere con- 
 taining tire-damp, the inflammable gas inside the envelope will 
 burn without igniting that which is outside. 
 
 I will now describe briefly the lamps most commonly in use in 
 mines containing inflammable gas ; they are named after their 
 inventors, viz., the Davy, Clanny, Mueseler, Marsaut, and Hepple- 
 white-Gray lamps. 
 
 The ordinary Davy lamp (Fig. 594)* consists of a brass oil 
 vessel b, on to which is screwed a cylinder of wire gauze a, 
 about 1 1 inches in diameter and 4! to 5^ inches high. The 
 
 * The materials used in constructirg the lamps are indicated thus : 
 
 Glass "' '* JSrasa m Thin SlicctMctcU/ 
 
LIGHTING, 
 
 5*9 
 
 FIG. 591. 
 
 FIG. 595. 
 
 A 
 
 cylinder is further closed at the top by a cap of wire gauze e, 
 
 which overlaps the main gauze for a distance of i inch to i^ 
 
 inches. In the centre of the oil-vessel is a round tube containing 
 
 a cotton wick, which can be trimmed from the outside by a piece 
 
 of wire f passing up through the bottom. The gauze used has 
 
 28 holes or meshes per linear inch, or, in other words, 784 per 
 
 square inch. The wire varies slightly in size ; some which I 
 
 very carefully measured was '016 inch in diameter, and was 
 
 probably intended for No. 27 S.W.G. A maker of repute 
 
 informs me that he usually 
 
 employs No. 30 of the old 
 
 B.W.G. Speaking roughly, 
 
 the holes are -^ inch (^ mm.) 
 
 square. Three rods c, attached 
 
 below to a ring screwed on 
 
 to the oil-vessel and above to 
 
 a plate, protect the gauze to 
 
 a certain extent. The lamp 
 
 is carried by a strong wire 
 
 ring fastened to the top 
 
 plate d. Rape, colza, or seal 
 
 oil, alone or with the addition 
 
 of petroleum, are used as il- 
 
 luminants. 
 
 The Davy lamp has several 
 grave defects : in the first 
 place it gives very little light ; 
 and secondly, as pointed out 
 by the Royal Commission on 
 Accidents in Mines,* it will 
 fire an explosive mixture if 
 the velocity of the current exceeds 6 feet a second. According to 
 the photometric tests made for the Royal Commission by Professor 
 Clifton,"!" the light of the Davy lamp varied from 7 to 22 percent, 
 of that of a standard candle ; these were laboratory experiments, 
 in which the light was not further diminished by the accumula- 
 tion of dirt, grease, soot, and coal dust upon the gauze, as may 
 often happen underground, and nothing is .-aid about the absence 
 of illumination immediately above the lamp. 
 
 With the powerful ventilating currents in use nowadays, the 
 second defect is a very real one ; it is sometimes overcome by placing 
 the Davy lamp in a cylindrical tin case with a glass window. 
 
 It was very natural to attempt to remedy the first defect of 
 the Davy lamp by using glass instead of gauze, for the lower part 
 of the enclosing cylinder. 
 
 In the Clanny lamp (Fig. 595), constructed upon this principle 
 
 * Preliminary Report, 1881, p. xiii. 
 
 t Final lle)o>-t< 1 886, Appendix xxiv., p. 87. 
 
5- 
 
 OKE AND STONE-MINING. 
 
 FIG. 596. 
 
 the air which feeds the flame comes in through the gauze just above 
 the glass a, descends along its inner face and goes to the wick; 
 the products of combustion then pass up the centre. Nothing 
 separates the descending current of air from the ascending current, 
 and consequently the oil, from want of a direct supply of fresh 
 air, does not always burn so brightly as it does in a lamp fed 
 from under the gauze ; but the light is far better than that of 
 a Davy lamp. . The letter b represents one of the metal rods for 
 protecting the glass. Professor Clifton's experiments usually 
 gave 26 to 50 per cent, of the light of a standard candle, or, on 
 an average, more than twice as much light as the Davy. In a 
 current having a velocity of more than 6 feet a second it behaves 
 like the Davy, and ignites an explosive mixture. 
 
 Mueselw's lamp (Fig. 596) may be conveniently described as a 
 Clanny lamp, with a chimney a fixed above the flame, and attached 
 at the level of the top of the glass to a dia- 
 phragm or horizontal partition of wire gauze 
 b. The path taken by the air is shown by 
 the arrows. The fact of the inward current of 
 fresh air being kept separate from the outward 
 current of foul air assists the illuminating 
 power of the lamp. The wick is sometimes 
 ilat. 
 
 The Mueseler lamp, which is the only one 
 allowed in fiery pits in Belgium, is a favour- 
 ite in many countries, and leaving aside its 
 use in collieries, I may mention that it is the 
 only lamp employed at the very dangerous 
 ozokerite mines of Boryslaw and at the Mill 
 Close lead mine in Derbyshire. It has the 
 merit of going out in an explosive atmosphere, 
 and of so removing a cause of danger. The 
 lamp is extinguished because the chimney is 
 unable to carry off the products of combustion 
 quickly enough; they spread out under the 
 bottom edge of the chimney, and pollute the 
 fresh current to such an extent that it becomes incapable of 
 supporting the combustion of the oil. 
 
 The lamp will not stand being jerked or inclined, for any- 
 thing which will turn the currents out of their proper course 
 causes the bottom part of the gauze to be filled with the products 
 of combustion and puts the flame out. It is evident that when 
 the lamp is held in an inclined position, all the foul gas will not 
 go up the chimney, and that some will become mixed with the 
 inward current; a jerk downwards checks the supply of air 
 passing in through the gauze, and again the lamp is extinguished. 
 On the other hand, it resists a horizontal current better than 
 the two lamps mentioned previously. If the lamp is struck 
 
LIGHTING. 521 
 
 obliquely by tho current an explosion may sometimes take place 
 inside it. 
 
 Before concluding this very short account of the Mueeeler 
 lamp, it is important to point out that a mere diaphragm with a 
 chimney does not necessarily constitute a lamp of the original 
 Belgian pattern. The dimensions of the parts are carefully 
 prescribed by law in Belgium, for it has been found that a 
 slight departure from them may affect the properties of the lamp 
 very materially. 
 
 A lamp which has come largely into use of late years, and 
 especially in this country after the favourable report of our Royal 
 Commission, is that of M. Marsaut, of Besseges, to whom miners 
 
 FIG. 597. 
 
 FIG. 598. 
 
 are indebted for many useful investigations (Fig. 597). It is of the 
 Clanny type that is to say, it has a glass cylinder with the air 
 entering above it, and no chimney ; but it has the extra safety 
 afforded by a second or even a third gauze, and a bonnet or shield 
 of sheet iron. These additions enable it to resist currents of 2000 
 feet per minute ; other advantages are an illuminating power of 
 about two-thirds of a standard candle, simplicity and strength, for 
 the gauze is protected by the shield from accidental blows of the 
 pick or other sources of injury. The outer shield adds somewhat 
 to the weight of the lamp, but the slight diminution of portability 
 is amply repaid by the increased security which it affords. 
 
 The Hepplewhite-Qray lamp, with some modifications intro- 
 duced by Ashworth (Fig. 598), is of a totally different type; the 
 wick is fed with air coming in below the glass, through a ring 
 
522 ORE AND STONE-MINING. 
 
 of wire gauze d, on the inside of an annular chamber. When 
 testing for " gas," the openings at the bottom of three brass 
 tubes, through which the air passes into the annular chamber, are 
 closed, and the lamp draws its supply of air from the top of tubes. 
 The path taken by the air is shown by the arrows ; b b are the 
 holes by which the products of combustion escape. The glass 
 is no longer cylindrical, but is made in the form of a truncated 
 cone, with the object of illuminating the roof ; the smallness of 
 the top of the shield a conduces to the same desirable object. If 
 the inside of the glass is blackened at the back, the efficiency 
 for testing is decidedly increased, as images of the flame, such as 
 are reflected from both sides of the ordinary glass, no longer 
 trouble the observer. This lamp has the further advantage 
 for testing that it takes in its supply of air from the top, and 
 will therefore test a layer of air close to the roof which could 
 not be examined by an ordinary lamp, except by tilting it so much 
 that there would be danger of its going out. 
 
 Locks. In order to prevent careless and imprudent men from 
 risking their lives and those of their comrades by opening their 
 lamps, it is nece?>sary to lock them securely before they ere taken 
 into the workings. Various devices have been proposed and 
 adopted. , 
 
 A little bolt screwed in by a key like a large watch-key, through 
 the ring holding the glass or the gauze, was thought at first to 
 offer sufficient guarantee of security ; but it was soon found that 
 ingenious miners could pick a lock of this kind without difficulty, 
 and other plans had to be devised to baffle their skill. The nu\st 
 common systems employed are the lead rivet, the magnetic bolt, 
 and the Cuvelier fastening. 
 
 The lead rivet is placed through two holes, one in the brass ring 
 holding the glass and the other in the oil-vessel ; it is then firmly 
 squeezed with a pair of nippers, and thus impressed with a mark, 
 which can be changed from day to day if necessary. When this 
 has been done, the lamp cannot be opened without cutting the 
 rivet, which would at once be noticed when the miner handed ifc 
 in at the end of the shift. The lamp-man easily cuts the 
 rivet before proceeding to clean the lamp; the pieces of led 
 are collected, melted up again, and once more cast into rivets. The 
 cost of this very effective method of locking is but slight. 
 
 Several inventors have resorted to magnetism in order to 
 obtain an unpickable form of lock, and Wolf's fa>tening is one 
 of this description. It consists of a bolt held in its place by a 
 spring, which can only be drawn back when the lamp is placed 
 against a very powerful magnet. This form of lock is largely 
 used. 
 
 Cuvelier's ingenious fastening, which gives great satisfaction at 
 some French collieries, may be described as a vertical bolt which 
 keeps the lamp locked until it is set free by hydraulic pressure. 
 
LIGHTING. 
 
 FIG. 599. 
 
 The two ends of a piece of metal tube, bent into the form of a 
 circle, come close together under the bolt, whilst on the opposite 
 side there is a projecting tube with a very small hole. If hydraulic 
 pressure is exerted on the inside of the tube by means of an 
 accumulator acting through the little hole, the two arms tend to 
 straighten out, and the ends move a little away from one another ; 
 in so doing they allow the bolt to fall from its own weight and the 
 pressure of a spiral spring. The operation of opening is very 
 quickly performed, and the hole in the projecting tube is so small 
 only 3- to ~ of a millimetre in diameter that the quantity of 
 water used is insignificant. The hole is on the under side of the 
 tube and has not been found to become choked up by dirt, as 
 might have been expected. 
 
 Gas. Gas is employed for lighting pit-bottoms, hanging-on 
 places, or sidings, where there is a large amount of traffic. 
 
 Electric Light. Up to the present time, owing to its want of 
 portability, the electric light has not displaced candles and ordinary 
 lamps in the work of " getting " minerals, save 
 in a few special cases. It is true that various 
 small portable incandescent lamps have been in- 
 vented and tried, but until lately they have failed 
 to satisfy all the conditions which are necessary 
 for commercial success. 
 
 More promising than its predecessors is the 
 Sussmann. lamp, which is now coming into the 
 market. A (Fig. 599) is a steel case enclosing a 
 dry storage battery ; B is an outer protecting cylin- 
 der of glass, held between four upright rods, C ; 
 D is the vacuum bulb with the filament which 
 becomes incandescent ; E and F are conical 
 whitened reflectors destined to make the best 
 possible use of the light. The back half of the 
 glass cylinder is whitened for a similar reason. 
 
 The lamp is 2\ inches square at the base and 
 8 inches high ; it weighs 3 Ibs. 10 oz. (1-64 kil.). 
 One pattern is said to give a light of one candle- 
 power for fourteen or fifteen hours, and another 
 three candle-power for nine and a half hours. 
 The advantage of this lamp over those previously 
 brought forward is the absence of any liquid. The interior of 
 the battery is solid, and consequently the lamp can be held or 
 laid in any position. The company owning the patents is ready 
 to make contracts with mine- owners to supply lamps, charge 
 them daily, and keep them in repair for 4^. per lamp per week, 
 or about what oil alone is costing at the present time. 
 
 As regards its safety, it is stated, as the result of numerous 
 experiments, that the smallness of the filament prevents any 
 chance of its igniting explosive mixtures, in the event of both the 
 
5 2 4 ORE AND STONE-MINING. 
 
 outer cylinder and the bulb being broken. Like all other electric 
 lamps, it has the defect of affording no indication of fire-damp or 
 carbonic acid. 
 
 Where a fixed light can be used in other words, where the 
 nature of the excavation to be lighted is not rapidly changing 
 the electric light is rendering incalculable services. Thus, in 
 sinking shafts, a few incandescent lamps hung from an electric 
 cable enable the miner to do his work under unaccustomed con- 
 ditions of brilliancy. He not only gets better illlumination, but 
 he is relieved from all trouble about candles or lamps, and can set 
 about his work as a navvy would at the surface. This means a 
 saving of time which is often well worth paying for. While 
 blasting is going on, the lamps are drawn up out of the way of 
 stones which might be hurled up and break the glasses. 
 
 Fixed glow lamps form a convenient and desirable means of 
 lighting up pit-bottoms, on-setting places, levels and sidings where 
 the traffic is large, and ladder-ways and man-engines which are 
 much frequented. 
 
 When the area to be illuminated is large, an arc-lamp may be 
 employed with advantage. Among the first successful applications 
 of electric lighting to underground excavations may be mentioned 
 that of M. Blavier at the Angers slate quarries.* In the year 
 1879 he fixed two Serrin lamps in one of the large underground 
 chambers with an area of 2400 square yards, and he found that 
 they gave light enough for all the men at work. The total cost, 
 reckoning everything viz., coal, carbons, repairs, labour, deprecia- 
 tion of plant, and interest on capital was 50 francs a day ; the 
 gas formerly in use cost 54 franc-s a day and gave much less light. 
 The large chambers in the salt-mine of Maros-Ujvar in Hungary t 
 have been lighted up by electricity since 1880. The cost is some- 
 what greater than that of the tallow, oil, or petroleum formerly 
 in use ; but, per contra, the illumination is better, the men can do 
 more work and are more easily supervised, whilst the air of the 
 mine is not deteriorated by the products of combustion of the 
 lamps. Slanic salt-mine in Roumania has been lit with the 
 electric light in a similar manner since 1883. 
 
 In a previous chapter I described the working of the thick bed 
 of lead-bearing sandstone at Mechernich by large underground 
 chambers, which eventually are allowed to collapse. Of late years 
 arc lights have been largely used for illumination, although the 
 number of men in one chamber is never more than six and often 
 not more than two. The great advantage derived from the use 
 of the powerful light has been the possibility of removing with 
 safety thousands of tons of ore, which otherwise would have been 
 left undergound for fear of accidents in taking it down. 
 
 * Blavier, " L'Eclairage electrique aux Ardoisieres d'Angers," Annales 
 
 s Mines, ser. 7, vol. xvii., 1880, p. 5. 
 
 t Ocst. Zdtschr, . u. II. W., 1882, p. 296. 
 
LIGHTING. 525 
 
 It is proposed to use arc lights with reflectors, similar to the 
 naval search lights, for examining the roofs and sides of the large 
 underground chambers in the Welsh slate mines. 
 
 Arc lights stand in good stead when work has to be done at 
 night above ground. Thus, at Rio Tinto, the great open-cast 
 is lit up by two arc lights, one at each end of the major axis of 
 the elliptical pit. In the same way two arc lights of 2000 candle 
 power are used for night-work in washing down auriferous gravel 
 at the works of the Osceola Company in Nevada.* As the use of 
 electricity spreads for the purpose of transmitting power, we may 
 naturally expect further development of the lighting of parts of 
 mines from the same source. 
 
 * Eng. Min. Jour., vol. li., 1891, p. 630. 
 
CHAPTER XII. 
 
 DESCENT AND ASCENT. 
 
 Steps and slides Ladders Bucket or cage Man-engine, single and 
 
 double. 
 
 AT first sight this subject might seem scarcely to deserve a separate 
 chapter ; but if one considers the time occupied by the miner in 
 going to and from his work, and recollects that his hours are 
 reckoned" from bank to bank" i.e., from the moment he leaves 
 the surface till he reaches it again and if one further dwells upon 
 the terrible waste of energy involved by climbing up and down deep 
 shafts by ladders, it will be admitted that the question of descent 
 and ascent requires to be discussed. 
 
 Where mines are worked by adit levels, the men naturally walk 
 in along the ordinary roadways. Such mines, however, are 
 exceptional, and the workmen generally have to climb down and 
 up by ladders, or are lowered and raised by the winding 
 machinery. The means of access to and from the workings may 
 be classified as follows : 
 
 1. Steps and slides. 
 
 2. Ladders. 
 
 3 Bucket or cage. 
 4. Man-engine. 
 
 Steps and Slides. If the dip of a seam or vein is small, 
 an inclined pathway, leading down through the old workings, 
 forms a safe and pleasant travelling road into the mine, and it 
 has the further advantage that the ponies or horses can be 
 brought out at the end of each shift. 
 
 When the inclination reaches 20 it is well to have regular 
 steps, instead of making the men scramble down an irregular 
 path ; it is true that the miner, accustomed to the road, does not 
 lose so much time as a stranger in picking his way along a rough 
 or slippery track, but still a bad path causes a little unnecessary 
 delay which is best avoided. Steps are much less fatiguing than 
 ladders placed so flat that part of the weight of the body has to 
 rest upon the arms. 
 
 Steps may be cut in the rock itself, if it is hard enough, and if 
 not, wooden or stone stairs can be put in, with a handrail. When 
 the dip is too high for making the stairs straight, they may be 
 
DESCENT AND ASCENT. 527 
 
 arranged in a zigzag line, provided that the excavation affords 
 sufficient space. The height of the steps should not exceed 
 8 inches, so as to avoid a fatiguing lift of the foot. 
 
 In parts of the Sicilian sulphur-mines,* where the dip does not 
 exceed 30 to 35, the steps are from 8 to 10 inches high and 12 
 to 14 inches broad, and occupy the whole width of the travelling 
 road ; if the dip is from 40 to 50, two sets of steps are made, so 
 that the level of the tread on one side corresponds with the middle 
 of the height on the other. This system is known as that of the 
 scaloni rotti, and greatly facilitates the ascent up such steep 
 roads. 
 
 In some of the Austrian salt-mines the men descend by wooden 
 slides inclined at angles varying from 30 to 50, flattening at the 
 bottom so as to reduce the velocity gradually ; the miner can 
 increase his speed by leaning forwards or lessen it by leaning 
 back. The ascent is by steps. 
 
 Ladders. Ladders are very largely used in ore-mines all over 
 the world, but they vary a good deal in different countries. In 
 Mexico and in Chili, the common ladder is merely a pole with 
 notches at the sides for receiving the feet. These ladders, 
 especially when worn, are better fitted for barefooted or sandaled 
 miners than for those wearing a heavy and unyielding boot. 
 
 The so-called " centipede ladder," met with in out-of-the-way 
 parts of Australia, and even sometimes seen in Europe, is very 
 properly condemned by the inspectors of mines in Queensland.f 
 It is made of a single pole, often a sapling with the branches cut 
 off, with auger holes through which wooden pegs are inserted at 
 regular intervals. The projecting pegs form the rungs of the 
 ladder. If such a ladder is new, with the pegs set evenly and 
 firmly, and placed at a proper angle, it will serve for shallow 
 depths ; but ladders of this description are usually put in by men 
 who are not good at carpentry, they are hung vertically, the pegs 
 are uneven originally or are allowed to get rotten, and the suc- 
 cessive ladders are not securely joined ; the task of climbing then 
 becomes a dangerous one. 
 
 The ordinary ladder consists of two sides and a series of rungs 
 (staves, Cornwall). The principal points that have to be considered 
 are the material, the size, and the mode of fixing. 
 
 In this country the mine ladder is most commonly made with 
 wooden sides and iron rungs. The sides are easily formed by 
 putting a sawcut through a plank as supplied by the timber- 
 merchant. 2 inches thick by 8 inches wide, giving two pieces 4 by 2 
 inches ; pitch-pine is largely used on account of its durability. 
 The two sides are fastened together temporarily, and auger holes 
 bored through them both, so that they match exactly. The rungs 
 
 * Parodi, SulV Estrazione dello Solfo in, Sicilia. Florence, 1873, p. 24. 
 t Ann. Rep. Dcp. Mines, Queensland, for the Tear 1889, p. 122; 1890, 
 p. 130. 
 
5'2& ORE AND STONE-MINING. 
 
 are made of pieces of round iron, f to | inches in diameter. It is 
 true that one may see | inch iron employed for the rungs ; but, 
 leaving aside the question of safety, this is false economy. The 
 thin rung wears quickly, if there is much traffic, and soon has to 
 be replaced, entailing an expense which would have repaid the 
 extra cost of the thicker iron in the first instance. 
 
 On the Continent wooden rungs are common, and oak is 
 preferred on account of its durability ; the wooden stave is often 
 made flat, instead of round, so that it may last longer, and iron 
 sides may be seen where dry rot is very bad. A ladder made 
 entirely of wood is lighter than one with iron staves, and 
 this is an advantage if it has to be moved about much. In places 
 where an ordinary ladder would be knocked to pieces by blast- 
 ing, such as the bottom of a shaft in course of sinking, a short 
 length of chain ladder is put in ; the sides are made of pieces 
 of chain, and iron rungs are attached at suitable intervals. 
 Wire rope is also used for the sides of ladders, and Rochebeau 
 uses steel tube for the rungs. He supplies the ladders of this 
 description, which can be rolled up into a coil and kept in readi- 
 ness in case of an emergency. 
 
 A very important point is the distance between the rungs : ib 
 should be chosen so as not to cause too great a lift of the foot at each 
 step, whilst at the same time the number of steps must not be 
 increased out of reason. Experience shows that a distance of 10 
 inches from centre to centre is very suitable ; ladders with a step 
 of 1 1 inches or 12 inches are far more fatiguing to climb. The 
 two end rungs often have collars, and, like them, the middle rung 
 is screwed at the ends for nuts ; these add to the general strength 
 of the ladder; the sides are thus kept permanently about n 
 inches apart. If not secured in some fashion the ends may come 
 together a little and the middle bulge out. It is advisable to have 
 a uniform pattern for all the ladders in a mine, such as 14 feet, 
 for instance, and when an old ladder has tobe replaced, a suit- 
 able new one is ready in stock, without any delay for taking 
 measurements or making it. Two such ladders joined together 
 form a very convenient length for a " footway " in a shaft ; they 
 make a ladder 28 feet long, and allowing 4 feet to project above 
 the platform, for safety and comfort in getting on and off, there 
 remains a length of 24 feet for actual climbing between the plat- 
 forms or sollars. The two ladders can be fastened together by an 
 iron strapping-plate on each side, held in position by the nuts of 
 the two terminal rungs. Where the ladders have plain rungs at 
 the ends a strong wooden cleat nailed on to both ladders makes 
 the connection. In making the joint between two ladders, care 
 should be taken to maintain the proper distance between the 
 staves and the regular inclination ; for when once a man has got 
 into the rhythm, so to say, of climbing, he is liable to miss his 
 step and fall if a rung fails to come just where he expects it. 
 
DESCENT AND ASCENT. 
 
 5-9 
 
 FIG. 600. 
 
 Fig. 600 represents a ladder * made entirely of iron, such as is 
 largely used in mines in the north of France. The sides are of flat 
 iron, 7 x 70 mm. (about J- x 2f ins.) and the rungs are of round 
 iron, 22 mm. (| inch) in diameter; they are 252 mm. (9^9 inches) 
 from centre to centre. Three of the rungs are bolts with nuts, 
 and the others are riveted ; the manner of joining two ladders 
 by a cotter bolt with a square end is evident 
 from Fig. 60 1. The iron may be galvanised 
 to prevent rust'ng. Ladders of this descrip- 
 tion weigh 10 kil. per metre (20 Ibs.) per 
 yard. 
 
 Platforms (sollara, Cornwall) should be fixed 
 at short intervals; though our British law 
 allows them to be placed 60 feet apart, the 
 distance can be reduced with great advantage 
 
 FIG. 60 1. 
 
 
 3 a 
 
 
 ] O 
 
 
 , . 
 
 
 
 
 e 
 
 i 
 
 
 1 e 
 "01 > OfirC 
 
 
 o 
 
 
 o 
 
 
 
 
 $ 
 
 
 
 
 
 
 to 1 8, 20, or 24 feet in perpendicular or 
 highly inclined shafts. A much shorter 
 interval would mean too many changes, and 
 a longer one would render falls more danger- 
 ous, besides curtailing the number of enforced 
 short rests, which are a relief in climbing up 
 from great depths. One side of the ladder 
 may be fastened to timber in the shaft 
 by strong staples ; and if not, it should be 
 kept rigid by stays, so as to prevent any 
 swaying. 
 
 Lastly comes the question of the angle at which the ladder 
 should be inclined. The mine -owner should spare no pains to 
 render the "travelling" as safe and as easy as possible, and 
 should recollect that the miner climbs with the least amount of 
 fatigue, when the greater part of the work of raising the body is 
 thrown upon the muscles of the legs and not upon those of the 
 
 * One of the patterns supplied by Remain Sartiaux, of Henin-Lielard, 
 Pas-de-Calais. 
 
 2 L 
 
53 
 
 ORE AND STONE-MINING. 
 
 arms ; the part played by the arms should be keeping the 
 body in a proper position and preventing falls. It may here be 
 noted that the miner does not climb a ladder like a bricklayer or 
 a house- painter. The latter place their hands upon the sides of the 
 ladder ; the miner grasps the rungs, and even if his foot slips, or 
 if a faulty rung gives way under him, he has a chance of saving 
 himself. In climbing down he frequently misses every alternate 
 stave with his hands, or, in other words, he makes two steps with 
 his feet for one grasp with the hand. 
 
 The most convenient angle for ladders is about 20 from 
 the vertical ; if they are much flatter than this, the arms 
 have to be used in order to prevent the body from falling 
 forwards ; if they are steeper, the arms have to lift part of the 
 weight of the body. In either case there is fatigue for the arms, 
 and in the latter the danger of falls is increased ; these dis- 
 advantages become very marked when the ladders are placed in a 
 vertical or overhanging position. Ladders so fixed are prohibited 
 by law in this country, for it is not only the life of the man who 
 falls which is endangered, but he may sweep off several men 
 beneath him. Unfortunately, our present law does not go quite far 
 enough ; it forbids a vertical ladder, but permits a ladder inclined 
 at an angle of i or 2 from the vertical, provided the shaft is not 
 large enough to admit of any better arrangement. In other words, 
 it does not compel the mine-owner to sink 
 a shaft large enough for a proper ladder- 
 road. The Belgian law,* enacted twenty- 
 one years before ours, is more wisely 
 worded ; it decrees that no ladder shall be 
 inclined at an angle of less than 10 from 
 the vertical. 
 
 Furthermore, of the two arrangements 
 shown in Fig. 602, A is better than B, 
 because it not only affords a greater in- 
 clination for the ladders, but also renders 
 it less likely that a man will drop through 
 the opening (manhole) in the platform 
 (sollar) if he loses his hold and falls. In 
 planning the regular permanent ladder-road 
 for the miners, it is well to avoid shafts 
 in which other operations, such as winding 
 
 or pumping, are going on. By law, in this country, the ladder 
 compartment has to be partitioned off from the winding compart- 
 ment ; a better plan, if possible, is to provide an entirely separate 
 shaft for a footway. In vein mines, a number of the winzes can 
 conveniently be set apart for " travelling " purposes. Occasionally 
 the ladderway is made double in the upper part of the mine, so 
 
 FIG. 602. 
 
 * Arrete royal du Janvier 1851, Article 2. 
 
DESCENT AND ASCENT. 531 
 
 as to prevent loss of time at the change of the shifts, when an 
 ascending stream of men meets a similar descending stream. 
 
 Some of the matters just mentioned may seem trifling, but, 
 leaving aside the question of safety, the economy derived from 
 fixing the ladders at the best possible inclination is by no means 
 small. To make this apparent, we must recollect the depths to 
 and from which men have to climb viz., 300, 400, and even 
 500 yards or more. It is, therefore, important to save every 
 unnecessary expenditure of energy, which, though trifling for one 
 ladder, becomes considerable if very frequently repeated. When 
 a mine has reached a depth of 100 yards, and a fortiori when it 
 has exceeded it, mechanical appliances should certainly be intro- 
 duced for raising and lowering the men, because time and strength 
 are wasted by climbing ; besides which, medical men are agreed 
 that excessive ladder-climbing is injurious to the health of the 
 miner. Therefore upon hygienic and upon financial grounds, one 
 of the first thoughts in working a mine should be the conveyance 
 of the men down and up the shaft with the least possible fatigue, 
 by means of machinery. 
 
 Buckets and Cages. This method of going down and com- 
 ing up from mines recommends itself by its simplicity, and when 
 carried out with modern appliances it is remarkably safe 
 
 If the machinery is being worked by hand, the miner usually 
 stands with one foot in the kibble and uses the other to guide 
 himself, while he holds the rope in his hands ; this guiding is 
 specially necessary when going down an inclined winze with 
 rough and rugged sides. Some men prefer to have one foot in 
 a loop at the end of the rope, whilst others like a special stirrup. 
 
 At the ozokerite mines of Boryslaw, and also in sinking oil- 
 wells in Burma, special precautions are taken in case the men 
 should become unconscious from breathing an atmosphere highly 
 charged with noxious gases. In every case the man is secured 
 by a second rope, so that he can be drawn up even if he falls 
 from the bucket. The Boryslaw safety-gear is a strong leathern 
 waist-belt to which is attached a broad strap divided into two at 
 each end. One thong passes over each shoulder and is buckled 
 to the belt, and one under each leg is attached in a similar 
 manner. An iron ring between the shoulders completes the gear. 
 It serves for attaching the second rope, or life-line, coiled upon a 
 separate windlass, and paid out as fast as the main rope with the 
 bucket in which the man stands with one leg. Many of the 
 shafts worked in this way are more than 150 yards deep, and one 
 has attained a depth of 262 yards (240 metres). 
 
 Guides are compulsory in this country after a depth of 50 yards 
 is exceeded, unless the owner of the mine has obtained an exemp- 
 tion from the inspector of the district. , I explained in the chapter 
 upon winding how they can be applied to the kibble or bucket 
 even in a sinking shaft; but the usual method of ascent and 
 
532 
 
 ORE AND STONE-MINING. 
 
 descent is by the cage, or some form of guided box. Little need be 
 said about the process of lowering and raising, for it is practically 
 the same as winding mineral. Rules are made denning the 
 number of men allowed to ride at one time, and generally there 
 is a bar near the top of the cage which the men can hold, in case 
 there should be a little jerk. In some countries it is necessary 
 that the cage should be so enclosed that there is no possibility of 
 a man falling out during his rapid ride. As sending the men 
 down and up in this fashion interferes with the winding of 
 minerals, access to the cage should be easy ; even stooping causes 
 a little loss of time, and the despatch of the men into the mine 
 will be expedited if the cage is high enough for them to walk 
 in upright without any thought for their heads. If the space is 
 too low for standing up conveniently, the men may be made to 
 crouch down in mine-wajrgons, which are pushed on to the cage as 
 if they contained mineral. 
 
 The extent of the interference with the regular winding opera- 
 tions will be best understood by examples. The Government 
 regulations at Mansfeld* do not allow a greater speed than 328 
 yards per minute (5 metres per second) when men are being 
 wound. At Ernst I. shaft, which is 411 yards (376 metres) deep, 
 it was reckoned, a few years ago, that seven hours out 'of the 
 twenty-four were occupied with the descent and ascent of 1069 
 persons, thus : 
 
 Persons. 
 
 Morning from 4. 30 A.M. to 6.30 A.M., 2 hours ... 450 
 
 Afternoon,, 12.30 P.M. 3.45 P.M., 3$ ... 415 
 
 Evening 9.15 P.M. n.o P.M., if ... 204 
 
 Total . . ' . ./ . . 7 ... 1069 
 
 At Ernst III. shaft, which is 273 yards (250 m.) deep, the 
 figures were as follows : 
 
 Persons. 
 
 Morning from 5.0 A.M. to 6.15 A.M., labours ... 260 
 
 Afternoon,, 1.15 P.M. ,, 2.30 P.M., i| ... 234 
 
 Evening 9.30 P.M. 10.30 P.M., i ... 149 
 
 Total 3i - 643 
 
 The cage at the former shaft took seven men at a time, and 
 that of the latter, sixteen men, as it was double-decked. 
 
 With the object of relieving the ordinary winding-plant from 
 this task in one part of the district, a new shaft was sunk solely 
 for raising and lowering the men. 
 
 The British law demands that, in addition to the guides already 
 mentioned, there should be a cover overhead, so as to protect the 
 men from things accidentally falling down the shaft. The use of 
 
 * Der Kupferschieferbergbau und der Hiittenbetrieb zur Verarbeitung der 
 gewonnenen Minern in den beiden Mans/elder Kreisen der Preuss. Provinz 
 tiachsen. Halle an der Saale, 1889, p. 72. 
 
DESCENT AND ASCENT. 533 
 
 a single-linked chain is forbidden, except for the short coupling 
 piece connecting the cage to the rope. There must be flanges to 
 prevent the rope from slipping off the drum ; the winding 
 machine has to be provided with an adequate brake and a proper 
 indicator ; and, lastly, there must be means of signalling up and 
 down from every landing-place in the shaft. In some countries 
 safety catches are compulsory. 
 
 An ingenious and useful method of signalling is that of Mr. 
 Armstrong, who inserts an electrically insulated wire into the centre 
 of the winding rope for the purpose of communicating from the cage 
 itself to the engineman, no matter whether the cage is in motion 
 or not. The electric wire is brought into contact with an insulated 
 metal ring placed upon the crank shaft of the engine, and a 
 copper lever pressing upon this ring places the wire in communi- 
 cation with a small battery. The wire rope itself serves as a 
 return. The circuit can be completed by pushing a button inside 
 the cage, or another placed upon the roof, and the ringing of a 
 bell at the surface gives the necessary signals to the engineman. 
 This rope, which is made by Messrs. Haggie & Co., of Sunder- 
 land, is being used with success at collieries in the north of 
 England, and at one of them a separate shaft is set apart for the 
 men, so as not to interfere at all with the winding of coal ; the 
 cage carries twenty men at once, and is always in charge of a con- 
 ductor, whose duties resemble those of the attendant at an hotel 
 lift or elevator. By merely pressing a button he signals direct to 
 the engineman to start or to stop as required. 
 
 At mines under the Coal Mines Act in this country, the rate 
 of winding men must not exceed three miles an hour after the 
 cage has reached a point in the shaft which is fixed by Special 
 Rules. However, this regulation applies only in cases where the 
 hoisting apparatus is not provided with some automatic contriv- 
 ance to prevent overwinding. In Germany a speed indicator 
 has to be applied when men are being raised or lowered ; among 
 instruments of this class may be mentioned the tachometer of 
 Messrs. Schaffer and Budenberg, which indicates the rate of 
 winding by a pointer on a dial in full view of the engineman. 
 
 Winding by the cage is not confined to perpendicular shafts. 
 At Carn Brea Mine in Cornwall a two-decked cage, holding six- 
 teen persons, runs in a shaft which is perpendicular for the 
 first 120 fathoms and then follows the changing dip of the lode 
 for 170 fathoms more. The inclination varies from about 10 to 
 30 from the vertical. In a shaft of .this kind it is impossible to 
 wind with safety at speeds which are common at collieries ; 
 nevertheless the cage does very useful work, and as the rope is 
 renewed every four months, there is little chance of a breakage. 
 The cage at Junge hohe Birke* Mine, near Freiberg, consists of 
 
 * Fr cilery s Berg- und Huttenwesen, 1893, p. 156. 
 
534 
 
 ORE AND STONE-MINING. 
 
 FIGS. 60* , 604. 
 
 A 
 
 A B 
 
 n 
 
 five small compartments one above the other, each forming, as it 
 were, a separate link of a chain ; the cage can thus accommodate 
 itself to bends in the shaft. Each compartment takes two men. 
 
 Man-engine. The first man-engine was put up in the Hartz 
 in 1833, and nine years later a similar machine was fixed in 
 Tresavean Mine in Cornwall. Since that time this useful means 
 of conveying men up and down shafts has been resorted to in 
 other mining districts, such as Belgium, Westphalia, and Saxony. 
 Two kinds of man- engine are in use the double-rod and the 
 single-rod machines. 
 
 The double-rod, or original man-engine, consists of two 
 reciprocating rods, like the main rods of pumps, carrying small 
 platforms upon which the men stand. The stroke 
 is from 4 to 16 feet, and the little platforms are 
 arranged so that they are always opposite each 
 other at the beginning and end of each stroke. 
 
 Figs. 603 and 604 represent the rods in the two 
 final positions. A man who wishes to go down, 
 steps upon platform b (Fig. 603), the rod B goes 
 down and A goes up, so that b is brought oppo- 
 site c (Fig. 604). The man steps across from b 
 to c, the rod A makes a down stroke, and B an 
 up-stroke. Platform c is now opposite d (Fig. 
 603), and the man again steps across ; 
 and thus, by constantly stepping 
 from the rod as it completes its 
 down-stroke, the man is gradually 
 conveyed to the bottom of the shaft. 
 By reversing the process, or, in other 
 words, by stepping off on to the 
 opposite platform as soon as the rod has completed its 
 up-stroke, the man is raised to the surface without any 
 fatigue beyond the very slight effort of stepping side- 
 ways. If each rod makes four up and down strokes 
 of 10 feet each per minute, the rate of ascent or 
 descent will be 80 feet per minute. 
 
 The single-rod man- engine has one rod carrying 
 steps, while fixed platforms are arranged in the 
 shaft so as to correspond exactly with them (Fig. 605). 
 If a man wants to go down, he steps on to A when 
 the up-stroke is completed ; the rod goes down and 
 the step A is brought opposite the fixed platform A, \ ,,-j j | 
 on to which he steps off. He then waits on b until ma U mm 
 the rod has finished its up-stroke. B is brought 
 opposite b, he steps on to B, the rod goes down and he is brought 
 opposite c, where he again steps off and waits. By reversing the 
 operation he is gradually lifted up to the top of the shaft. The 
 single-rod engine may be used by men going up while others are 
 
 FIG. 605. 
 
DESCENT AND ASCENT. 535 
 
 going down, provided that there is sufficient room upon the fixed 
 platforms (sollars, Cornwall). It is best to have platforms right 
 and left, as shown in the figure, and then the ascending men step 
 off always to the left, for instance, while the descending men take 
 the right hand sollars. The ascending man steps on to the man- 
 engine as soon as the descending man steps off, and so the rod 
 may be always carrying men up or down. The usual stroke in. 
 Cornwall is 12 feet, and there are from 3 to 6 double strokes 
 per minute. With 5 strokes the men descend 10 fathoms a 
 minute, or, in other words, a descent or ascent of 300 fathoms 
 occupies half-an-hour. However, after the first man has reached 
 the bottom, the re^t will be coming down at the rate of five a 
 minute. The reciprocating motion is best obtained from a crank 
 (Fig. 706), because in this case the speed is gradually diminished 
 at the dead points, and the danger of an accident in stepping off 
 and on is thereby lessened ; man-engines, however, are sometimes 
 driven by direct-acting engines, and, at Laxey Mine, in the Isle of 
 Man, a water-pressure engine furnishes the motive power for 
 one of these machines. 
 
 Man-engine rods are constructed of wood or iron ; and at St. 
 Andreasberg, in the Hartz, each rod was replaced by two wire 
 ropes. Like a pump rod the man-engine rod requires proper 
 balance-bobs and catches, and for the safety of the men a handle 
 is provided at a convenient height above each step. Sloping 
 boards should be fixed under each platform, so as to make a 
 funnel-shaped passage guiding the man's head into the proper 
 channel, in case he is not standing upright when "riding" up. 
 A useful addition is a small wire rope passing down from sollar 
 to sollar, and placed within easy reach of a man when standing 
 on a step ; he grasps this with one hand as he steps off on going 
 down, and steadies himself by it if necessary. When riding up, 
 he passes through the sollar and sees where he is going to step 
 before he gets off, so it is not required on both sides of the fixed 
 platform. There should be a signal line, with means of working 
 it, at every sollar, for enabling any miner to ring and stop the 
 man-engine in case of an accident. It is well, too, to have a 
 ladder-road at the side of the man -engine, in order to afford a 
 means of going up or down in the event of some unexpected 
 breakdown of the machinery ; but the plan of fixing this ladder- 
 way between the two rods of a double engine is not to be com- 
 mended, for the wider the space between the rods the greater the 
 chance of an accident. 
 
 The man-engine has the advantage that it can be safely applied 
 in inclined and crooked shafts, and it is convenient in vein-mining 
 where the men have to work at very many different levels. 
 
 The cost of raising and lowering men by the machine is not 
 great. At Dolcoath, a tin mine in Cornwall, more than 400 
 fathoms deep, it was reckoned a few years ago that i|c. per man 
 
536 ORE AND STONE-MINING. 
 
 per day covered all expenses, including interest upon the capital 
 expended and depreciation of plant. 
 
 Judging by what has taken place during the last ten years, it 
 seems likely that the man-engine will eventually die a natural 
 death. It has all but disappeared at Mansfeld, being replaced 
 by the safer and more convenient cage, and there seems little 
 probability of new machines being erected in Cornwall. 
 
( 537 ) 
 
 CHAPTER XIII. 
 DRESSING. 
 
 I. Mechanical processes: (i) Washing in order to separate clay, mud and 
 sand (2) Hand-picking (3) Breaking up, subdivision, or shaping 
 (4) Agglomeration or consolidation (5) Screening or sifting. II. Pro- 
 cesses depending upon physical properties: (i) Motion in water (2) 
 Motion in air (3) Desiccation (4) Liquefaction and distillation (5) 
 Magnetic attraction (6) Separation according to degree of friability. 
 III. Processes depending upon chemical properties : (i) Solution, eva- 
 poration, and crystallisation (2) Atmospheric weathering (3) Calci- 
 nation (4) Cementation or precipitation by iron (5) Amalgamation. 
 
 Examples Loss in dressing Sampling. 
 
 UNDER the convenient term of " dressing" are included the 
 processes by which the miner prepares his mineral for sale, or by 
 which he extracts a marketable product from it. These processes 
 are very various, and cannot all be properly comprised under the 
 French heading " Preparation mecanique," because, in addition to 
 using mechanical means, the miner often invokes the aid of heat, 
 magnetism, or chemical affinity, in order to separate the valuable 
 material, from the worthless rock with which it is associated in 
 the earth. It must also be recollected that there is a borderland 
 between mining and metallurgy, on which both miner and smelter 
 may fairly claim a footing, because the former does not always 
 send away his ore in the same state of elaboration. Some may be 
 inclined to cut the knot by saying that the business of the miner 
 is at an end when the mineral is landed at the surface ; but in 
 actual practice this is the exception, and the person in charge of 
 the mine has usually to superintend certain processes which are 
 carried on in order to obtain a readily saleable article. 
 
 I propose in this chapter first to describe the various dressing 
 processes, and then to explain how they are applied to the 
 most important minerals with which the miner has to deal. 
 
 In order to have a clear idea of the principles which guide 
 the miner, it is requisite that we should classify the processes 
 which he employs; and we may at once make three main 
 divisions, according as the process is effected solely by mechanical 
 means, or is based upon the physical or chemical properties of the 
 minerals treated. This classification is somewhat arbitrary: 
 differences of opinion may exist, for instance, concerning solution, 
 some persons considering it as a chemical process, others, as a mere 
 
538 ORE AND STONE-MINING. 
 
 change of state without any chemical action ; again the process by 
 which a physical property is brought into play is usually effected 
 with the aid of mechanical appliances ; and lastly, chemical and 
 physical actions may both be involved in the method of treatment. 
 It must, therefore, be understood that the classification is estab- 
 lished rather for the convenience of the student, than with the 
 idea that the subdivisions of the subject are strictly denned in 
 reality. It will be seen also as we proceed, that many of the 
 sub-classes refer to exceptional processes applicable only to special 
 minerals. 
 
 The following table gives an outline of the operations employed 
 in dressing : 
 
 I. MECHANICAL PROCESSES. 
 
 1. Washing in order to separate clay, mud and sand. 
 
 2. Hand-picking. 
 
 3. Breaking up, subdivision, or shaping. 
 
 4. Agglomeration or consolidation. 
 
 5. Screening or sifting i.e., classification according to size. 
 
 II. PROCESSES DEPENDING UPON PHYSICAL PROPERTIES. 
 
 1. Motion in water. 
 
 2. Motion in air. 
 
 3. Desiccation. 
 
 4. Liquefaction and distillation. 
 
 5. Magnetic attraction. 
 
 6. Separation according to degree of friability. 
 
 III. PROCESSES DEPENDING UPON CHEMICAL PROPERTIES. 
 
 1. Solution, evaporation and crystallisation. 
 
 2. Atmospheric weathering. 
 
 3. Calcination. 
 
 4. Cementation or precipitation by iron. 
 
 5. Amalgamation. 
 
 i. MECHANICAL PROCESSES. 
 
 (i) WASHING. The object of washing is twofold : remov.nl 
 of earthy impurities, and preliminary cleansing previous to hand- 
 picking, for the valuable mineral, as it comes from the mine, is 
 often completely masked by a coating of dirt. 
 
 The process is carried out by hand or by machinery. Tho 
 simplest appliances are the pan and the batea, which are specially 
 used in the case of gold and tin. The pan is a circular dkh made 
 of tin-plate or stamped iron or steel, about 15 or 16 inches in 
 diameter at the top and 10 or 1 1 at the bottom, with a depth of 3 
 or 4 inches. After having been partly filled with the mineral to 
 be washed, it is held in a pool of water, or a vat, in which it can 
 be moved so as to impart a circular motion to its contents. By 
 suitably inclining the edge, the muddy stream is made to flow off, 
 more clean water is taken on, and the process is repeated until there 
 
DRESSING. 539 
 
 remains nothing but well-washed sand and gravel in the bottom. The 
 big stones are taken out and examined, and thrown away if worth- 
 less ; large nuggets, if present, are now visible and can be picked 
 out, whilst the small stones and sand are again mixed with water 
 and washed, so that the lighter particles flow over the edge and the 
 heavy ones remain in the pan. By careful manipulation the 
 water is made to run repeatedly over the residue, and separate the 
 various ingredients according to their specific gravities, as will be 
 explained later. The pan, therefore, acts not only as a washer, but 
 also as a concentrator. 
 
 Though the main use of the pan is for prospecting, it must be 
 remembered that very large quantities of alluvial gold have been 
 extracted by its aid. 
 
 The batea fulfils the same purpose as the pan. It is usually 
 a shallow conical bowl made of wood, stamped sheet iron, 
 hammered copper, or spun aluminium or copper. Convenient 
 dimensions are: diameter 18 to 20 inches and depth z\ to 3 
 inches. In some parts of India the wooden gold-washing dish is 
 rectangular. The mineral is treated much in the same way as in the 
 pan, but the batea has the great advantage of bringing all the 
 heaviest particles to a point, instead of an edge. Much gold has 
 been obtained with this primitive appliance, especially in South 
 America and Central America, whilst in the Malay Peninsula 
 it is used for extracting tin ore from gravel, and in Brazil 
 for washing out diamonds. In prospecting the batea is in- 
 valuable. 
 
 If large quantities of mineral have to be handled, it is necessary 
 to separate the adherent dirt in some cheaper fashion. Occupying 
 an intermediate position between the hand-bowls and the rotary 
 machines are simple washing pits of different descriptions. 
 
 Some of the lead ore of North Wales occurs in the form of solid 
 lumps of galena enveloped in clay. The ore coming from the 
 mine is thrown into a stone-lined pit about 18 inches deep, partly 
 filled with water, in which it is pushed backwards and forwards 
 until the galena is separated from its clayey matrix. This kind of 
 washing pit is known as a "jobbing buddle." 
 
 Phosphatic nodules are cleansed from sand in a similar manner, 
 by being raked or shovelled backwards and forwards in long 
 wooden troughs full of water. 
 
 The Australian puddling machine is an example of an 
 appliance for doing similar work by the aid of a horse or other 
 available power. It is a circular pit in which gold-bearing gravel 
 is stirred up with water by knives attached to radial arms, which 
 are carried round by a vertical axis. 
 
 The rotary washing machine employed at the diamond mines 
 (Fig. 606) is identical in principle. The object is to free the 
 weathered " blue ground " from the finest sand and mud and leave a 
 clean gravel in which the diamonds shall be distinctly visible. The 
 
540 
 
 ORE AND STONE-MINING. 
 
 rotary washer is an annular iron pan A (Fig. 606) 8 to 15 feet in 
 diameter and 16 inches to 2 feet deep externally, whilst the inner 
 rim, B, 4 feet in diameter, is only 6 inches deep. In the centre 
 is a revolving vertical shaft, C, carrying 8 or 10 radial arms, 
 D, each provided with 6 or 7 vertical blades which dip into the 
 mud and gravel, and stir it up as they revolve. At De Beers 
 mine the washers are usually 14 feet in diameter. The stuff is 
 fed in at the outer circumference by a shoot coming from a 
 screen, arid the muddy water escapes over the low inner rim of 
 the pan. The teeth or stirring knives are arranged so as to bring 
 
 FIG. 606. 
 
 SCALE 
 
 JNS.I2 o 
 
 DECIMETRES iQ 
 
 j FE.E.T 
 2 MfLTRE.3 
 
 the heavy gravel towards the outer circumference. As a pre- 
 caution, the muddy water flowing out of the washer is run into 
 a similar machine, and is again stirred up so as to catch any 
 diamonds which may by chance have escaped in the first operation. 
 When the pan has been at work for twelve hours, a sliding door 
 is pulled out at the bottom, through which the gravel falls into a 
 truck underneath, as it is drawn round by scrapers attached to 
 the arms. 
 
 Another form of mechanical washer* (Fig. 607) is a revolving 
 sheet iron drum, made in the form of a truncated cone revolving 
 upon a horizontal axis, and provided with internal stirring blades. 
 The " stuff " to be washed is fed in at the centre of the small end 
 
 * Linkenbach, Die Aufbereitung der Erze, Berlin, 1887, plate II. 
 
DRESSING. 541 
 
 with a stream of water. In Fig. 607, a is the drum, b the conical 
 mouth, cc the arms which attach the drum to the central shaft d ; 
 ee are teeth, f the shoot from a hopper, g a pipe bringing water, the 
 amount of which can be regulated by a cock. The greater part of 
 this particular drum is perforated, and it acts as a sizing machine 
 after having done the washing ; m is the driving pulley, h an iron 
 trough catching the discharge of the sieve, and i a small trough 
 which takes the stones discarded by the sieve. 
 
 This machine is intended for washing small stuff (" smalls ") 
 previous to picking. The washing of the larger lumps is often 
 effected by turning a stream of water upon them over a coarse 
 iron grating. 
 
 FIG. 607. 
 
 t I 
 
 (2) HAND-PICKING. No process is simpler in principle, it is 
 merely the separation by hand into classes of varying quality and 
 richness ; the difficulty in practice is to know how far it should 
 be carried, before the mineral is treated by machinery. 
 
 In many cases hand- picking may begin underground, and 
 where worthless rock can be so separated without difficulty, 
 it should be removed with care, so as to avoid useless ex- 
 penditure for tramming, hoisting and dressing. If a mineral 
 is specially valuable, it is often worth while picking it out and 
 sending it up by itself, with a view to preventing loss or theft in 
 transit, or loss in dressing due to the admixture of a large pro- 
 portion of refuse. Picking of this kind is resorted to in working 
 rich pockets of gold or silver ore under the superintendence of a 
 foreman. Pieces of pure ozokerite are picked out by the 
 Boryslaw miners and sent to the surface in sacks, and the men 
 are stimulated to do the work as thoroughly as possible by a 
 premium paid for the clean lumps. 
 
 By the dim light of a candle the picking process cannot, as a 
 rule, be carried further than the separation of worthless rock, and, 
 
542 ORE AND STONE-MINING. 
 
 occasionally, the selection of some very rich pieces of mineral ; nor, 
 if the light were better, would it be advisable to do more, for the 
 underground traffic would be complicated if a number of classes of 
 mineral were made, and the work of picking can be better per- 
 formed by keen-eyed boys and girls at the surface than by the 
 miners underground, especially after they have passed middle age. 
 Picking is generally carried on after the mineral has been 
 subjected to a washing process of some kind. The washed 
 mineral is spread out on a table, and boys and girls, standing by 
 the side, separate the stones that lie before them according to their 
 richness and the subsequent processes they will have to undergo. 
 A scraper made of a piece of iron, bent as shown by 
 FIG. 608. Fig. 608, assists them in drawing the lumps towards 
 them or into a box, waggon, or barrow by the side of 
 the table. 
 
 In a lead-mine we may have (a) clean galena ; (b) 
 mixed ore, i.e., pieces consisting partly of galena and 
 partly of barren veinstone ; (c) barren veinstone and 
 pieces of the surrounding rocks (country). This is a 
 most simple case ; but very frequently one has to deal 
 with a deposit producing the ores of two or three 
 metals, especially in the case of lead and zinc, and 
 then the classification into various qualities becomes 
 O more complicated. 
 
 Where the amount of mineral to be picked is con- 
 siderable, labour may be economised by self-discharging tables, 
 of which there are two kinds revolving round tables and tra- 
 velling-belts. 
 
 With the former the mineral is fed on at some point of the 
 circumference and the picking is done by boys or girls standing 
 around. They select pieces of certain qualities and richness as 
 the table revolves in front of them, and finally, when a revolu- 
 tion is all but completed, nothing remains on the table but mineral 
 of one quality, which is swept into a box or waggon by a fixed 
 projecting scraper. 
 
 Endless belts are made of hemp, wire-gauze, or steel plates 
 attached to endless chains, and they are sometimes as much as 
 4 feet wide. The refuse is picked off as the mineral travels by, 
 and the clean product can at once be delivered into railway 
 waggons, ready for despatch to smelting works or to some further 
 process of dressing. 
 
 (3) BREAKING UP, SUBDIVISION, OR SHAPING- 
 Reduction in size is necessary for various reasons. Even when 
 an ore is clean enough for the smelter, the large lumps are 
 often crushed by the miner for the sake of obtaining a fair sample 
 of the whole, or of supplying a product which is at once fit for 
 the furnace. Fertilisers, cements and pigments have to be finely 
 ground before they can be used, and the grinding may or may 
 
DRESSING. 
 
 543 
 
 not take place at the mine. The chief object of breaking up, 
 however, is to set free the particles of ore, which are generally 
 found enclosed in or adhering to particles of barren veinstone. 
 
 Few processes in dressing are of more importance than the 
 proper breaking up of the ore or other mineral. A very large 
 number of machines are employed suitable for the different 
 substances which have to be treated, and it will be impossible 
 
 FIG. 609. 
 
 RAGGING 
 
 within the limits of this chapter to do more than pass the most 
 important in review in a somewhat summary manner. 
 
 The breaking may be done by hand or by machinery. 
 
 The processes of breaking by hand may be divided, according to 
 the precise object in view, into : 
 
 a. Breaking with the sledge hammer [ragging and spoiling}. 
 
 b. Cobbing. 
 
 c. Bucking. 
 
 d. Splitting. 
 
 c. Trimming into shape with the saw, axe, hammer, or knife. 
 
544 
 
 ORE AND STONE-MINING. 
 
 a. Breaking with, the Sledge Hammer. The term 
 "ragging" is applied, in Cornwall (Fig. 609)*, to the process of 
 breaking up the very big lumps (rocks) as they come from the 
 mine by a large sleJge hammer weighing about 10 or 12 Ibs. The 
 
 FIG. 6 10. 
 
 SPALL1NC. 
 
 work is done by men, who, in addition to breaking the lumps, 
 may separate the broken pieces into various categories according 
 to quality. 
 
 Spoiling is work of a similar nature, but performed with a 
 smaller sledge, weighing 4 or 5 Ibs., which in Cornwall can be 
 wielded by a woman (Fig. 610). Sometimes there is a little 
 
 FIG. 6n. 
 
 COBBING. 
 
 picking at the same time. The process of spalling is often a 
 preliminary to crushing by stamps or rolls. 
 
 6. Cobbing. Cobbing is a special kind of breaking with a 
 small hammer, in which the blow is directed with the object of 
 knocking off a piece of poor rock from a lump of mixed ore and 
 refuse. The work is usually performed by women (Fig. 611), 
 
 * Henderson, " On the Dressing of Tin and Copper Ores in Cornwall," 
 Proc. List. C.E., vol. xvii., 1857-58, plate 7. 
 
DRESSING. 
 
 545 
 
 girls, or boys, who commonly sit down and strike the lumps upon 
 an anvil of some kind, often an old stamp-head. As the lumps 
 are held in position by the left hand, a badly directed blow may 
 
 FIG. 612. 
 
 BUCKING MILLS. 
 
 cause a nasty wound ; to prevent injuries of this kind, the girls 
 formerly employed in cobbing copper ore, at the Mona and Parys 
 mines in Anglesey, wore pieces of iron around their fingers, and 
 short pieces of india-rubber tube are used for the same purpose. 
 
 c. Bucking. Bucking is breaking with 
 a very broad flat hammer in order to reduce 
 an ore to coarse powder. The hammer, called 
 a "bucking-iron," is about 4 inches square 
 with a steel face ; the handle is from 1 8 inches 
 to 2 feet long. The ore is struck upon a thick 
 flat plate of iron (Fig. 612). 
 
 d. Splitting. Splitting is required with 
 slate, and also with stone which will rend 
 along certain directions other than cleavage 
 planes, such as planes of bedding. It is done 
 with a wedge of some kind, increasing in 
 sharpness with the thinness of the slice re- 
 quired. Blocks of slate are split by the 
 Welsh quarrymen with a stout wedge into 
 slabs about 3 inches thick, and the process 
 is then repeated with a thin one (" cyn maen 
 
 hollti") (Fig. 613) until they obtain a roofing material often not 
 more than \ or J inch thick. 
 
 2 M 
 
 - - *.- 
 
546 OKE AND STONE-MINING. 
 
 e. Trimming. Trimming into shape is necessary with many 
 kinds of stone. Thus the Bath freestone is resawn by hand at 
 the surface (Fig. 156), if the blocks are not quite suitable for the 
 market as they come from the mine. The hearthstone raised at 
 Godstone in Surrey is hewn into neat blocks by a peculiar double- 
 headed axe, whilst paving- stones, chert, and gun-flints are 
 fashioned with the hammer ; roofing-slate is chopped into rect- 
 angular pieces with a large knife. 
 
 Many of these hand-processes are gradually disappearing, 
 owing to the introduction of machinery which will perform the 
 work with a saving of time and labour. 
 
 Machines for breaking up, subdividing, or shaping ores and stone 
 may be classed as follows : 
 
 a. Breakers with reciprocating jaws. 
 
 b. Stamps. 
 
 c. Rolls. 
 
 d. Mills. 
 
 e. Edge-runners. 
 /. Ball-grindtrs. 
 g. Disintegrators. 
 
 h. Conical grinders and breakers. 
 i. Centrifugal grinders. 
 j. Pneumatic pulverisers. 
 k. Miscellaneous pulverisers. 
 I. Sawing machines. 
 m. Planing machines. 
 n. Slatemaking machines. 
 
 a. Jaw-breakers. These machines, often called rock-breakers 
 and stone -breakers, crack stones by the near approach to one 
 another of two powerful iron or steel jaws. The best known 
 stone-breaker is the machine invented by Blake, which has 
 rendered inestimable services to the miner for the last thirty 
 years, and the introduction of which constituted a most important 
 step in advance in the art of ore-dressing. Its mode of action is 
 very simple. When the shaft A (Fig. 614) revolves, an eccentric 
 raises the pitman B, and by means of the toggle- plates C causes 
 the movable jaw D to approach the fixed jaw E, and so crack any 
 stones lying between them. During the descent of the pitman the 
 jaw D is drawn back by an india-rubber spring. The jaws are 
 usually toothed, the ridges of one jaw being opposite the grooves of 
 the other when the machine is employed for breaking stones at 
 mines ; if the object is to make road-metal, the two sets of ridges 
 are brought opposite each other. The wearing parts of the two 
 jaws E E and D D are replaceable, and if these castings cannot be 
 immediately obtained in a distant country, it is possible to do 
 good work with flat plates of steel. 
 
 The stone-breaker used at mines commonly has the renewable 
 part of each jaw made of one casting instead of two as represented 
 in the figure. The distance between the two jaws, and conse- 
 
DRESSING. 
 
 547 
 
 qnently the fineness of the product, can be regulated by raising 
 or lowering the wedge-piece on the right-hand side of the figure, 
 or by inserting other toggle-plates. 
 
 The Blake rock-breaker, with the improvements introduced by 
 Marsden, is made in various sizes, so as to take stones as large as 
 34 inches by 18 inches; the smallest machine is 10 inches by 8 
 inches in the mouth. 
 
 "Various similar machines are in the market. Baxter claims that 
 he produces fewer small chips and less dust matters of import- 
 ance in making road-metal by his so-called " knapping-motion." 
 Marsden has a breaker with what he calls a " lever motion," in 
 which the toggle-plate moving the jaw forwards is impelled by a 
 
 FIG. 614. 
 
 bent lever worked by crank. Hall has two movable jaws placed 
 side by side which act alternately ; as all the parts are balanced, 
 less power is said to be required to drive it. Lester's machine is 
 very simple, as the moving jaw is driven directly by the pitman 
 without the intervention of any toggle-plates. 
 
 For crushing to finer sizes, Marsden has an ingenious pulveriser, 
 It resembles his stone-breaker by having two jaws, one fixed and 
 the other movable, but the moving jaw has a rubbing as well as a 
 squeezing action. The machine is supplied with a sieve, so that 
 any part of the product not fine enough for use is returned 
 automatically so as to be recrushed^ 
 
 The Dodge crusher (Fig. 615*) differs from those just described 
 
 * Copied by permission from a paper by Mr. A. H. Curtis, which may be 
 consulted with advantage by those who desire information on the subject 
 of crushing : " Gold-quartz Keduction," Proc. Inst. C. E., vol. cviii., 1891-9?, 
 p. 108. Further details are given by Professor Egleston. in his useful 
 paper, "California Stamp Mills," Engineering vol. xli., i88b r pp. ig f 85, 
 163, 256. 
 
548 
 
 ORE AND STONE-MINING. 
 
 in having the moving jaw pivoted below, instead of above. 
 Consequently the effect of the stroke is felt most at the top. 
 One object of this arrangement is to obtain a more uniform 
 product than is possible with a constantly varying discharge orifice, 
 like that of the Blake breaker. 
 
 FIG. 615. 
 
 THE OODGE CRUSHER. 
 
 b. Stamps. Though used at mines for several centuries, 
 stamps still hold their own in spite of many competing forms of 
 crushing machinery. The simplest mode of describing stamps 
 is to say that they are pestles worked by machinery in large mortars. 
 In most instances the blow of the pestle is caused by its mere 
 weight, sometimes a spring is added, and occasionally the action of 
 gravity is aided by compressed air, or by steam pressure. We 
 thus have four kinds of stamps : 
 
 a. Gravitation stamps. 
 /S, Stamps with spring. 
 7. Compressed air stamps. 
 5. Steam-hammer stamps. 
 
 A little study of the accompanying figures (616-620*) will 
 explain the most important characteristics of a modern stamp- 
 battery. 
 
 a. A A (Fig 6 1 6) are blocks of timber forming the solid founda- 
 tion, which is required on account of the heavy pounding action of 
 the machinery ; B B, the transverse sills, with the battery-posts 
 C 0, the braces E and the tie-timbers D D form the framework 
 holding the mortar or battery-box (kofer, Cornwall) F, in which 
 the mineral is pounded by any one of the five stamps moving 
 up and down in it. G is a perforated plate or screen which pre- 
 vents the mineral from leaving the mortar until it has been 
 brought down to the required degree of fineness. H is the shaft 
 carrying cams, which lift the stems by tappets ; K K are the 
 ends of the stems or lifters of the stamps proper; L is the 
 pulley through which motion is transmitted to the cam shaft by 
 
 * Curtis, Op. tit. 
 
DRESSING. 
 
 549 
 
 the belt upon the driving pulley M. N is the gear by means of 
 which the driving belt can be tightened. 
 
 FIG. 6 1 6. 
 
 10 STAMP BATTERY. WOODEN FRAME. 
 
 Each stamp proper, K K, consists of a turned rod of iron with 
 tapering ends, either of which will fit into a corresponding hole 
 in a cast-iron cylinder known as the " head" (Figs. 617 and 620). 
 
 FIG. 620. 
 
 FIG. 617. 
 
 FIG. 6 1 8. 
 
 FIG. 619. 
 
 SINGLE DISCHARGE MORTAR 
 
 The conical hole or socket in the bottom of the head receives the 
 shank of the "shoe," which is made of cast-iron, cast-steel, or 
 forced steel. When worn the shoe can be removed from the head 
 
OEE AND STONE-MINING. 
 
 FIG. 621. 
 
 by driving a steel key into a slot above it (Fig. 620), and the stem 
 or lifter is extracted in a similar manner by means of a second 
 slot at right angles to the first. 
 
 The mortar is shown on a larger scale in Fig. 617. It is a 
 cast-iron box with an opening E at the back for feeding, and one 
 in front, into which is wedged the frame F of the screen. Some- 
 times there is a screen behind as well as one in front, or screens 
 at both ends as well as at the two sides. 
 
 Fig. 618 represents the tappet, a hollow cylinder of cast-iron, 
 which is fastened to the lifter by steel keys and a gib. The gib is 
 
 a piece of wrought-iron fitting the 
 curved surface of the lifter and capable 
 of being jammed against it tightly 
 when steel keys are driven into three 
 holes in the tappet. As the shaft H 
 revolves, the cams (Fig. 619) lift the 
 tappets, and at the same time cause a 
 slight rotation of the stamp, which 
 conduces to regular and even wear. 
 
 The head B, with its shoe C (Fig. 
 617), drops upon a cylinder of similar 
 metal known as the die, and it is be- 
 tween C and D that the mineral is 
 pulverised. Both shoe and die wear 
 away and have to be changed from 
 time to time. The worn shoe and die 
 represented in Fig. 621 were reckoned 
 to have stamped 150 tons of gold 
 quartz at the Morgan mine, North 
 Wales, before they were given up ; 
 they were made of Fraser and Chal- 
 mers' forged steel. The order in 
 which the heads drop is not invariable; 
 the object of any arrangement is to 
 make each head do its fair share of 
 
 work. Egleston mentions six different orders of dropping which 
 are in use, and this shows how much opinions are divided on the 
 subject. Among them may be mentioned 3, 4, 5, 2, i, and i, 
 
 5> 2 4, 3- 
 
 The screens through which the pulverised mineral has to pass 
 are made of punched iron, steel, or copper plates, and occasionally 
 of wire gauze. The holes are round, or in the form of long narrow 
 slots. The size of the holes is better expressed by their actual 
 dimension than by their number per linear inch or centimetre. 
 
 The total weight of each stamp when new, that is to say stem, 
 head and shoe, varies from 500 to 950 Ibs. ; weights of 700 to 
 800 Ibs. are common. The precise height and number of the drops 
 are further points requiring consideration ; the height varies 
 
DRESSING. 551 
 
 generally from 8 to n inches, and there are 70 to 100 drops 
 per minute. Ore may be stamped dry or web ; in the latter case, 
 water constantly flowing into the mortar- box carries oft' the 
 mineral through the screens in the form of a muddy stream 
 known as " pulp." Egleston reckons that the quantity of water 
 ut;ed in wet stamping is from 5 to J cubic foot per stamp per 
 minute, or 200 to 300 cubic feet per ton of rock stamped. 
 
 The quantity stamped per head per day must necessarily vary 
 within very wide limits, according to the weight of the stamps, 
 the nature of the stone treated, and the degree of fineness desired. 
 Speaking roughly, it may be said that each head will stamp 2 tons 
 per 24 hours and require 2 h.-p. 
 
 Regular feeding is of much importance, and several automatic 
 arrangements can be applied to the battery for securing the 
 desired result. Most frequently a tappet upon one of the stems 
 comes into play when the stamp has a longer drop than usual, 
 owing to want of ore under it, and strikes a lever which brings 
 the ore-feeding contrivance into action. 
 
 /3. Spring stamps are but little used. Patterson's " Elephant " 
 stamps belong to this class : the object of the inventor was to secure 
 a stronger and quicker blow than would be given by a mere fall, 
 and so enable a small machine to do more work than would be 
 possible if gravitation were acting alone. The stamp is worked 
 by a crank, and interposed between the striking head and the 
 connecting rod there is a strong spring, which assists by its recoil 
 and allows for the varying height of the ore in the battery-box. 
 
 y Husband's pneumatic stamps were designed with the same 
 intention viz., a quicker and a harder blow. The stem or lifter of 
 the stamp is attached to a piston working in a cylinder which is 
 lifted rapidly up and down by a crank. There are holes in the 
 cylinder which allow the air to escape during the middle of the 
 stroke, but after it has been raised beyond a certain point, 
 the air below the piston becomes compressed and the stamp is 
 lifted. The cylinder in its downward course travels quicker than 
 the stamp would fall, and compressing the air above the piston 
 helps to drive it down and with it the stamp ; it thus increases 
 the force of the blows, which can be given at the rate of 140 per 
 minute. Though good results have been obtained in some cases, 
 these stamps have not made their way into general use, for mining 
 engineers seem to consider that the simplicity of the ordinary 
 stamps, and the ease with which any slight defects can be repaired, 
 make up for the disadvantages which Husband tried to remedy. 
 
 d. We now, lastly, come to the steam-hammer stamp, which has 
 proved a most eflELcient machine at the Lake Superior mines for 
 the treatment of rock containing native copper. The first 
 stamps of this kind were constructed by Ball in 1856 \ since then 
 great improvements have been made, and the present Leavitt 
 stamp will crush 250 tons of copper-bearing rock in 24 hours. 
 
552 ORE AND STONE-MINING. 
 
 The Ball* stamp (Fig. 622) consists of a vertical steam-cylinder, 
 C, with the stamping head attached to the piston-iol. The 
 various parts are designated as follows : D, cast-iron die ; E, 
 cast-iron shoe ; F, frame of mortar ; G G, grates of punched 
 sheet steel ; H H, cast-iron head posts ; L, cast-iron sills or 
 girders; M, cast-iron mortar; P, pulley by which the valve is 
 
 FIG. 622. 
 
 f 7 I o 5 10 IS FEET 
 
 1 I I UJ 1 1 1 ' 1 1 1 
 
 M . I O'S I 2 3 4 M ET RES* 
 
 driven ; E, R, cross sills ; S, shoot supplying the ore ; T T, spring 
 timbers ; U, " urn " or cistern supplying water ; Y V, cast-iron 
 lining plates, resting upon a cast-iron ring surrounding the die ; 
 Y, pulley by which the stamp is rotated. 
 
 The slide-valve is worked from the pulley P by the elliptical 
 spur-wheels indicated by the dotted lines ; the valve is opened 
 fully for making the down-stroke, and the pressure of the steam 
 
 * Rathbone, "On Copper Mining in the Lake Superior District," Proc. 
 Jnst. Mecli. Eny., 1887, p. 96. 
 
DRESSING. 
 
 553 
 
 FIG. 62?. 
 
 greatly increases the blow due to gravity, but for making the 
 up-stroke the steam is admitted sharply, and in just sufficient 
 quantity to lift the head. 
 
 The peculiarity of the Leavitt * stamp lies in the differential 
 steam-cylinder (Fig. 623). There are two cylinders, one above 
 the other : a large one A with a piston B, above a small one C 
 with a piston D. Steam is admitted on to the top of piston 
 B through the valve at E, and is exhausted through a valve at 
 F into the condenser. The space under the piston D in the 
 cylinder C as well as the annular space G- 
 is filled with steam admitted through the 
 opening H, and kept by a regulator at a 
 uniform pressure sufficient to raise the 
 stamp. The stamp is thus lifted by the 
 lower piston, and is forced down by the large 
 upper one against the constant pressure 
 exerted by the lower. The valves regu- 
 lating the admission of the steam and the 
 exhaust valves are worked by cams upon a 
 shaft driven by a belt from some independ- 
 ent source of power. The cams which 
 open the steam and close the exhaust valves 
 are fixed, but the cams which close the 
 admission of steam and open the exhaust 
 can be adjusted at pleasure. 
 
 The moving parts of each Leavitt stamp 
 at the Calumet and Hecla mine weigh about 
 5000 Ibs., and the blow is struck with a 
 velocity of 20 to 22 feet per second. The 
 
 number of blows is 98 per minute ; the screens are made of the 
 best steel y 1 ^ inch thick, punched with round holes -^ inch in 
 diameter, and speaking roughly about 10 tons of rock an hour 
 are stamped fine enough to pass through them, and are carried 
 away by water to the concentrating machinery. 
 
 c. Rolls. Rolls were introduced into the West of England in 
 the early part of the present century to replace bucking by hand. 
 They are a pair of smooth, fluted, or toothed cylinders, made of 
 cast-iron or steel, which revolve in opposite directions, and crush 
 any stone which is allowed to fall between them. 
 
 The cylinders or rolls are generally from i foot to 3 feet in 
 diameter, and i foot to 3 feet wide ; they are kept pressed 
 together by levers or springs. For crushing metallic ores, the 
 diameter of the roll is generally from two to three times its 
 width. 
 
 The original form of crushing rolls, and one still largely used 
 
 * F. G. Cogging. "Notes on the Steam Stamp/' Enyinecring, vol. xli., 
 1886, pp. 119, 130, 200. 
 
554 
 
 OHE AND STONE-MINING. 
 
 in this country, is represented in Fig. 624, in which the letters 
 have the following meanings : G, hopper, into which the ore is 
 shovelled from the floor, H H ; A B, the two cylinders or rolls 
 shown on a larger scale in Fig. 625. The roll B ha,s plummer- 
 blocks which can slide along a bed-plate, and so allow the opening 
 between it and the roll A to be increased or diminished ; C is a 
 bent lever, to one end of which is attached a weighted box, whilst 
 the other constantly presses a pin against the plummer-block 
 of B ; the crushed rock after leaving the rolls falls into a 
 revolving cylindrical sieve. All that fails to pass through the 
 sieve drops into the " raff- wheel " E, which has buckets on the 
 
 FIG. 624. 
 
 face turned towards the crusher; these carry up the coarse 
 fragments as the wheel revolves and tip them on to a sloping 
 apron F, whence they fall again into the hopper G to undergo a 
 further crushing.* 
 
 One end of the shaft of the roll A is coupled to the main driving 
 shaft of the machine, which carries the raff- wheel ; the other end 
 has a cog-wheel which gears into a similar one on the shaft of B, 
 and so drives it. The inclined sieve is driven from the shaft 
 of A by means of bevel gearing. 
 
 An improved form of the Cornish rolls has been introduced by 
 Krom,f and is meeting with approval. His improvements are : 
 
 * Ferguson, " On the Mechanical Appliances used for Dressing Tin and 
 Copper Ores in Cornwall," Proc. Inst. Mech. Eny., 1873, plate liv., and 
 p. 133. 
 
 t "Krom, " Improvements in Ore-crushing Machinery," Trans. Amer. Inst. 
 M. E., vol. xiv., 1885, p. 497. 
 
555 
 
 FIG. 626. 
 
 DRESSING. 
 
 Steel tires, pulley gearing, housing 
 to enclose the rollers, swinging 
 pillow-blocks, tie-bolts to take the 
 crushing strain, hopper for auto- 
 matically ensuring a regular feed. 
 
 The tires (Fig. 626) are made of 
 mild forged steel,* and are held by 
 two cores in the form of truncated 
 cones. One of the cores is shrunk 
 firmly on to the main shaft, the 
 other is split on one side, but when 
 drawn in towards its fellow by 
 bolts, it grips the shaft very tightly, 
 and at the same time fastens the 
 
 tire securely. The main shaft (Fig. jrT ' * T O ,'**** 
 
 627)f is driven by a pulley, indi- 
 cated by the clotted line, revolving at the rate of 80 to 100 times 
 
 FIG. 627. 
 
 INS. 12 
 
 SCALES 
 
 7 FEET. 
 
 DECIMETRES ID 
 
 METRE 
 
 * Messrs Bowes Scott and Western use a special steel of their own 
 which is said to be exceedingly durable. t Curtis, op. cit. 
 
556 ORE AND STONE-MINING. 
 
 a minute ; the other shaft is driven at the same speed, but in the 
 opposite direction, by crossing the driving belt of the smaller 
 pulley. The bearing of the shaft of the movable roll is carried 
 by a swinging pillow-block pivoted underneath, and constantly 
 drawn towards the other roll by the strong spiral springs. The 
 upper part of the figure represents the bottom of the hopper 
 which supplies the rolls, and the oscillating feed-tray, set in motion 
 by an excentric. 
 
 Actual experience extended over a considerable time has proved 
 that a pair of Krom rolls at the Bertrand Mill, in Nevada, will 
 crush 150 tons of quartzose silver ore in 24 hours, so as to 
 pass through a screen with 16 holes to the linear inch. It 
 is claimed that less fine dust is produced with these rolls than 
 with stamps, a matter of importance, owing to the losses in dress- 
 ing or lixiviation when there is a large proportion of slime. 
 
 Fluted rolls are used in crushing rock-salt, and toothed rolls 
 are used for breaking comparatively soft minerals such as rock- 
 salt or gypsum, and even hard stone for road-metal. Some of the 
 rolls for rock-salt are made of toothed rings threaded upon a 
 shaft, and the two rolls are arranged so that the teeth of one lie 
 between those of the other. 
 
 d. Mills The term " mill " has a very vague signification 
 arcong miners ; all sorts of machines employed in crushing arid 
 grinding are commonly known as mills. I propose to restrict the 
 term to grinders, in which the working parts consist of flat or 
 approximately flat surfaces, one of which revolves. They are 
 called into requisition for reducing a mineral to a fine state of 
 division. 
 
 The typical mill of this class is the well-known flour mill, made 
 of two horizontal cylindrical stones, one fixed, the other revolving ; 
 sometimes it is the lower stone that is fixed, sometimes the upper. 
 Mills of this kind serve to grind barytes and fertilisers. The 
 stones are generally the French burr, and have to be dressed 
 from time to time as they wear. The mineral is fed in at the 
 centre, and is discharged at the circumference. Instead of one 
 top stone, there may be several separate pieces; this combina- 
 tion forms the " arrastra " employed for grinding and amalgama- 
 tion. 
 
 When the mill is made of iron, with iron or steel replaceable 
 wearing parts, it is generally called a " pan " ; like the arrastra, it 
 serves for fine grin ling and amalgamating. 
 
 Millstones need not necessarily be arranged horizontally ; the 
 first grinding of phosphate of lime is sometimes done by stones 
 set vertically, the moving stone being fixed upon a horizontal 
 axis. 
 
 e. Edge-runners. The edge-runner is a cylinder turning upon 
 a horizontal axis which is made to revolve around a vertical axis. 
 In its simplest form, it is a large stone wheel, the horizontal axis 
 
DRESSING. 
 
 557 
 
 of which is drawn round an upright post by a mule. The stone 
 crushes by its weight, and as it has to slide a little in order to 
 keep its circular path upon the bed, there is also a rubbing 
 action. This primitive form of edge-runner, known as the Chilian 
 mill, is employed in crushing and amalgamating gold and silver 
 ores. It is better to have two of the upright wheels at opposite 
 ends of the horizontal axis, as then the machine will work more 
 smoothly (Fig. 628). Each wheel is made of a strong tire of 
 chilled cast-iron wedged to a centre-piece of ordinary cast-iron, 
 and the bed is composed of sectors of chilled cast-iron, which can 
 
 FIG. 628. 
 
 be changed when they are worn. The driving gear may be above 
 or below. 
 
 f. Ball-grinders. In machines of this class the mineral is 
 pulverised by its contact with a number of cast-iron balls, which 
 are constantly rolling against each other when the case containing 
 them revolves. 
 
 Jordan's Centrifugal Grinder and Amalgamator is a circular 
 pan set upon an inclined axis with a few large iron balls like 
 cannon-balls which lie in the lowest part ; the machine is supplied 
 with crushed ore, which is soon ground fine and escapes through 
 a sieve placed around the outside of the pan. 
 
 The ingenious " Grusonwerk " ball-grinder (Figs. 629 and 630), 
 now made by Krupp, has a continuous feed and discharge. It con- 
 sists of a horizontal iron cylinder provided with several curved plates 
 
558 
 
 ORE AND STONE-MINING. 
 
 a a, which carry a number of steel balls. The stuff which is fed in by 
 the hopper h falls among the balls and is ground by their rubbing. 
 During each revolution of the drum, they drop five times as they 
 come to the edges of the plates. The ground mineral passes 
 
 through holes in the curved plates a a, and in the cylindrical sieve 
 c made of punched steel plate ; it now meets with the fine wire 
 gauze sieve d, which lets through all that is sufficiently pulverised 
 into the hopper s, whence it can be drawn off at pleasure. The 
 object of the punched steel sieve c is to prevent the unnecessary 
 wear of the fine wire gauze, which would naturally suffer if it 
 
DRESSING. 
 
 559 
 
 were exposed to the rubbing of coarse particles. The stuff which 
 is too coarse to pass through the fine outer sieve d is collected by 
 plates f and led back into the inside of the drum, where it is 
 a,gain exposed to the grinding action of the balls ; b b are lining 
 plates to prevent the wear of the ends of the cylinder ; 1 1 and i 
 denote bars closing a manhole which can be opened after the 
 removal of the sheet-iron casing surrounding the whole machine. 
 
 g. Disintegrators. Though any reduction of a mineral into 
 fragments or powder may be spoken of as " disintegration," the 
 word disintegrator has been appropriated by the grinders which 
 do their work with revolving bars or beaters. The best-known 
 machine of this class is Carr's disintegrator (Fig. 631). It 
 
 FIG. 631. 
 
 may be described as consisting of two cylindrical cages, revolving 
 one inside the other in opposite directions. Each cage is made up 
 of two concentric sets of bars, attached to a disc on one side and 
 to a ring on the other. The stuff which is fed into the centre is 
 thrown by the bars a a of the cage X, agairst the bars b b of the 
 cage Y ; thence it flies against the outer circle of bars c c of X, and 
 finally against the outer circle of bars d of the cage Y. It then 
 enters the circumferential space e, whence it can be allowed to 
 escape by a suitable opening in the outer casing f. 
 
 It is claimed for this machine that some of the pulverising is 
 done by the impact of the particles one against the other, and that 
 consequently the wear of the steel bars is less than might be 
 expected. However, the disintegrator is found most fitted for 
 comparatively soft materials, such as coal, gypsum, phosphates, 
 and rock-salt. 
 
 Instead of being arranged in the form of concentric circles in 
 
560 
 
 OftE AND STONE-MINING. 
 
 this cage-like manner, the beaters are sometimes radial, and, when 
 revolving at a very high speed, quickly reduce soft minerals to 
 powder. 
 
 h. Conical Grinders. In these grinders the crushing action 
 is usually produced by the revolution of a toothed cone, 
 inside a toothed cup; they thus resemble in principle the old- 
 fashioned coffee-mill. The Gates crusher (Fig. 632) acts differently. 
 It consists of an outer conical shell Q (Fig. 632), lined with 
 removable plates E, around which travels the conical breaking 
 
 head F carried by the upright spindle G ; both E and F are made 
 of chilled cast-iron. The lower end of the spindle G fits loosely 
 in the excentric box D, and is a little out of the centre ; it is 
 supported by the step P, which can be raised or lowered by the 
 screw S, in order to regulate the distance between the breaking 
 head and the shell, and consequently the fineness of the crushed 
 product. The upper end of the spindle G lies loosely in a socket 
 in the top framing C. The belt-pulley T U is loose upon the 
 shaft X, and it drives it by means of the clutch V, firmly keyed 
 to X, and the pin W. In case of any undue strain, the pin W 
 breaks and prevents damage, for the machine at once stops until 
 the obstruction is removed and a new pin has been inserted. 
 
DRESSING. 561 
 
 The bevel pinion upon X drives the bevel wheel L with its 
 excentric box ; when L revolves, the lower end of G is carried, 
 round excentrically, whilst the top moves in its socket. The 
 breaking head is thus made to approach and recede from each 
 part of the shell in succession, producing practically the same 
 effect as the reciprocating jaw of the Blake machine. The loose 
 collar I serves to keep out dust, and it has a hole J, through which 
 the machine is oiled ; N N are holes for conveying oil to the 
 space Y. The material to be crushed is fed in through three 
 large openings in the top frame ; it falls between E and F, is 
 
 FIG. 633. 
 
 IN? ifi 
 
 SCALE 
 
 3 
 
 OECIME.TRE.SIO 
 
 crushed by the movement of the breaking head and drops through 
 at Q Q on to an inclined apron, whence it slides into any con- 
 venient bin or receptacle. 
 
 i. Centrifugal Grinders. There are several grinding 
 machines in which a roller is whirled round upon the inside of a 
 cylinder against which it presses by centrifugal force. The 
 machine of this class most largely employed is the Huntington 
 mill (Figs. 633 and 634). A vertical shaft G, driven by bevel 
 gearing from below, carries a horizontal frame, which supports 
 four grinding rollers by the yokes Y Y lying in the pockets P. 
 The yoke allows a radial swing of the crushing roller against the 
 steel ring (Fig. 634) lining the pan in which the grinding takes 
 place. The construction of Paxman's improved roller is shown by 
 
 2 N 
 
562 
 
 ORE AND STONE-MINING. 
 
 Figures 635 to 637. R- is a steel ring which does the actual 
 grinding and is renewable when worn; it is fixed by woodtn 
 
 FIG. 634. 
 
 4-ROLLER HUNTINGTOM. MILL, 5 FT DIAMETER. SECTIONAL ELEVATION. 
 
 SCALE 
 TNSI8 01234567 FCLT 
 
 CECIMtTRLSiO 
 
 METRE. 
 
 wedges W to the core G-, and a sleeve bolted on to the core receives 
 the spindle S. From this explanation it will be seen that 
 
 FIG. 635. 
 
 FIG. 636. 
 
 FIG. 637. 
 
 PLAN. 
 
 PLAM AT A.3. 
 
 SCALE: 
 
 INS.I2 
 
 10 DECIMETRES 
 
 SECTIONAL ELEVATION. 
 
 the roller can revolve round the spindle S, but that the latter 
 does not turn upon its own axis when it is carried round by the 
 revolving frame supporting the yokes. A, B, C, D (Fig. 633) are 
 
DRESSING. 563 
 
 wooden scrapers which force the ore from the centre to the 
 circumference and so bring it under the action of the rollers. Ib 
 is easy to understand, therefore, that when the shaft G revolves 
 the rollers are thrown out by centrifugal force against the 
 annular lining, and crush and amalgamate the ore. The stuff 
 which is pulverised sufficiently fine escapes through a wire-gauze 
 sieve placed on the side of the pan, just above the lining ring. As 
 this sieve has not to resist the violent blows to which the 
 screens of stamps are liable, it may be made of much finer 
 material. 
 
 j. Pneumatic or Air- current Pulverisers. In one of 
 these pulverisers, it is proposed to crush the mineral by driving 
 the particles violently against each other by means of two power- 
 ful opposite jets of air or superheated steam. To use a familiar 
 illustration, it may be said that stone bullets are fired from 
 air-guns against each other with such force that they break 
 into powder upon meeting.* 
 
 The Cyclone Pulveriser, which excited a good deal of interest 
 at the Paris Exhibition of 1889, is based upon the same 
 idea. It consists of two beaters, something like screw-propellers, 
 driven at a speed of 1000 to 3000 revolutions per minute 
 in opposite directions in a small cast-iron chamber or case, in 
 the form of two truncated cones joined together at their larger 
 bases. The material to be crushed is delivered regularly into 
 this case by mechanical feeders, and the whirlwind created 
 by the beaters hurls the particles against each other with 
 such violence that they are almost instantly reduced to the 
 state of impalpable powder. The fine dust produced in this 
 way is constantly being sucked off by a fan, arid allowed 
 to settle in chambers whence it is conveyed mechanically 
 into hoppers. It can then be drawn off into sacks as required. 
 As the aspirating force of the fans can be regulated at 
 pleasure, the mineral can be brought to any desired degree 
 of fineness without any screening. Before treatment in this 
 machine, the material must be crushed small enough to be set in 
 motion by the hurricane -like blast of the beaters; in the case 
 of a mineral like quartz the fragments must not be larger than 
 walnuts. 
 
 k. Miscellaneous Pulverisers. These are so numerous 
 that it is out of the question even to think of giving their names. 
 The Sturtevant mill bears some resemblance in its mode of 
 action to the Cyclone pulverisers, inasmuch as the particles are 
 flung against each other with great force and break up in 
 mid-air, so to say. The stones are projected, however, by centri- 
 fugal force and not by air-currents. The Sturtevant mill is made 
 of two horizontal hollow cups which revolve at great speed in 
 
 * Industrial Review, vol. i., 1886, p. 56. 
 
564 ORE AND STONE-MINING. 
 
 opposite directions. The mineral is fed into the interval between 
 the two cups, and as fast as it makes its way into one of them, 
 it is hurled out again by centrifugal force and strikes other 
 fragments which are thrown across by the opposite cup. The 
 powdered mineral is drawn off through a screen by a fan. 
 Though the hurling cups are cylindrical, the crushed rock packs 
 itself into the ends and forms a conical stone lining which 
 prevents wear upon the iron surfaces. The Sturtevant mill is 
 said to be largely used in the United States for grinding 
 phosphate of lime. 
 
 The crushing machines in these descriptions have been 
 arranged according to their modes of construction ; it will be well 
 to point out in conclusion the uses to which they are applied, viz. : 
 
 1. Preliminary breaking : jaw-breakers, and Gates rock breaker. 
 
 2. Coarse crushing : rolls. 
 
 3. Fine crushing: stamps, rolls, mills of various descriptions, 
 
 and disintegrators. 
 
 1. Sawing Machines. These are necessary in the case of 
 stone and slate. The simplest machine is merely a plain blade 
 held in a frame, moved backwards and forwards by a crank or 
 excentric, whilst sand or chilled cast-iron shot and water are sup- 
 plied to aid the saw in its cutting work. The wire saw, already 
 described in a previous chapter, is employed for the same purpose. 
 
 FIG. 638. 
 
 In the case of slate, the work is usually done with circular saws. 
 The blocks, which have been split into slabs about 4 inches thick, 
 are fastened by wedges upon a sav/ing table, such as is represented 
 in Fig. 638. It is a cast-iron bed, A B, moving upon rollers, with 
 holes into which wedges can be placed for fixing the slabs of slate. 
 The pulloy drives the circular saw D, and at the same time 
 gives motion to a chain which draws the table along from one 
 end of its frame to the other. When the table has gone as far as 
 possible, the workman turns a hand-wheel which reverses the 
 motion, it is drawn back, and another set of slabs are arranged 
 so that they may be cut when it again moves forward. The 
 saw sometimes lies in a semicircular trough full of water, which 
 serves to keep it cool. 
 
 m. Planing Machines. Planing machines, somewhat similar 
 
DRESSING. 
 
 565 
 
 to those used in engineering shops, are employed for making the 
 smoo'th slate-slabs required for cisterns or billiard-tables. The 
 tool is held in one direction only and is not reversed after each 
 stroke. 
 
 n. Slate-making Machines. Greaves' circular slate-dressing 
 machine (Fig. 639) does precisely the same work as the quarry- 
 man's knife. It is a frame carrying two knives, C, which are 
 made to revolve by the pulley A upon the same shaft as the little 
 flywheel B. D is a fixed knife and E a cast-iron arm with a 
 number of notches on the inside, which are gauges for enabling the 
 quarryman to cut the slates to exact sizes. The belt pulley A is 
 thrown in and out of gear by a clutch. 
 
 Another machine for doing the same kind of work acts like a 
 
 FIG. 639. 
 
 guillotine, and has a knife which slides up anl down vertically 
 between guides. In both machines the action of the hand -knife 
 is imitated that is to say, the cut is made gradually along the 
 desired line. 
 
 (4) AGGLOMERATION OR CONSOLIDATION. Pro- 
 cesses of this kind are more particularly used in the case of coal 
 or brown coal, small particles of which can be pressed, either 
 with or without the addition of some cementing material, into 
 blocks of fuel of convenient shapes and sizes. At the same time 
 agglomeration is nob confined to coal : some of the poor clayey 
 phosphate of lime of the department of the Somme is made into 
 bricks, so that it may be readily burnt in kilns and deprived of 
 its moisture before being ground or sent away ; the so-called 
 " purple ore," the residue after the treatment of cupreous iron 
 pyrites by the wet process, and other kinds of fine iron ore, are 
 also sometimes made into bricks for the purpose of obtaining a 
 product suitable for smelting in the blast-furnace. 
 
566 ORE AND STONE MINING. 
 
 In order to get rid of water, washed graphite is pressed into 
 cakes, which are then ready for the drying stove. 
 
 (5) SCREENING- OR SIFTING. This is an important 
 branch of dressing. Sometimes it is a preliminary process which 
 is necessary or advisable previous to concentration by specific 
 gravity, or to picking by hand. Sometimes it is a final process 
 previous to sale, and for several reasons : the purchaser usually 
 requires cements, pigments, and fertilisers in a state of fine sub- 
 division and free from any coarse particles, or, contrariwise, he may 
 object to ores in the form of " smalls " or dust, which would choke 
 his smelting furnaces. Lastly, in a case of coal, which is beyond 
 the province of this treatise, the consumer prefers lumps, because 
 they burn more readily than dust and afford a rough guarantee 
 of purity ; whilst with anthracite the sifting process is carried out 
 on a very elaborate scale, in order to obtain suitable kinds of fuel. 
 
 Minerals are classified according to size by means of sieves 
 worked by hand or by machinery. 
 
 Hand-sieves are often employed underground for taking out 
 " smalls '' which are not acceptable to the purchaser. Thus at 
 the Merionethshire manganese mines, the workmen shovel the 
 fine stuff on to circular hand-sieves with holes | inch square, and 
 use all that goes through as material for filling up. In speaking 
 of the iron ore worked opencast in Northamptonshire a similar 
 separation of the fine was mentioned (Chap. VI., p. 288). 
 
 Sifting by hand is shown in Fig. 612 following bucking, so as 
 to ensure a proper degree of hand-crushing. It is more econo- 
 mical to employ a rectangular sieve fixed in a steeply sloping 
 position, and throw the mineral against it with the shovel. In- 
 clined gratings (grizzlies, U.S.) formed of bars of flat iron or steel, 
 on to which the waggons of mineral are tipped as they come from 
 the mine, are another form of sifting apparatus. 
 
 Machine-sieves. Most of the sizing at mines is performed by 
 sieves set in motion by machinery ; there are two principal kinds 
 of machine-sieves : flat oscillating sieves and revolving cylindrical, 
 conical, pyramidal, or spiral sieves. 
 
 The most common in ore mines arc revolving sieves, either cylin- 
 drical or in the form of truncated cones. A sieve of this kind is often 
 known as a " trommel." The word is expressive enough to the 
 German ; but it fails to tell the Englishman that the machine is 
 drum-shaped, and it can be tolerated in our language simply on 
 the score that it has so long been in use that it is practically 
 naturalised. 
 
 The sifting is done by wire web or by perforated sheets of metal, 
 either iron, steel, copper, brass, or bronze. Figs. 640, 641 and 642 
 represent sieves with round holes i, 2, and 5 millimetres respec- 
 tively. The holes are sometimes square or oblong. 
 
 The trommel consists of the perforated plate or the wire cloth 
 bent into the required conical or cylindrical form, and supported by 
 
DRESSING. 
 
 5^7 
 
 rings attached by arms to a central axis. The conical trommel has 
 the advantage that its axle can be placed horizontal, for the slight 
 inclination of the sieve causes the mineral to make its way from 
 the feed or smaller end to the discharge or larger end, provided 
 of course that the machine is in motion. If the trommel is 
 cylindrical, its axis must be inclined in order to secure the same 
 result. 
 
 FIG. 640. 
 
 FIG. 641. 
 
 i 
 
 FIG. 642. 
 
 When it is necessary to separate a crushed mineral into a 
 number of different sizes, the trommels are commonly arranged 
 so as to discharge one into the other. This plan has the dis- 
 advantage of requiring much gearing or many belts, for the 
 sieves have to be arranged step-fashion, each one a little below 
 its predecessor. If, on the other hand, only one long trommel 
 is used, with the holes increasing in size from the feed to the 
 discharge end, there is the evil of letting the very coarse stuff 
 
 FIG. 6420. 
 
 f, 
 
 -- 
 
 , 
 
 
 ltd) 
 
 
 
 
 apg^rert/.vfc- 
 
 junrf 
 
 > 
 
 n 
 
 rr 
 
 c 
 
 El 
 
 if 
 
 SCALE 
 
 2 METRE*. 
 
 IZIN. 423*5670 3 FEET 
 
 wear away the fine sieve, and cause more frequent repairs. 
 A good form, made by Jacomety and Lenicque of Paris, is 
 that shown in Fig. 64 2 a. The feed-end A is free from cross-arms, 
 having a large cast-iron ring B as support, and there are in all 
 three sieves C, E and F. Suppose, for instance, that the trommel 
 is supplied with stuff which has left a crusher sieve with no particles 
 bigger than 8 millimetres (^ inch) across ; this passes 011 to the inner 
 sieve C with holes of 6 mm. (J inch). The next ring, D, is of sheet 
 iron. In this way the coarsest stuff never touches the tine sieve. 
 
568 
 
 ORE AND STONE-MINING. 
 
 The two sieves, E and F, on the outside have holes of 2 mm. and 
 4mm. Consequently this trommel makes four classes : smaller than 
 2 mm., i.e., that which drops through the finest sieve, E ; size 2 to 4 
 mm., dropping through sieve F ; size 4 to 6 mm., discharged at G ; 
 and, lastly, size 6 to 8 mm., which passes out at H. An objection 
 to trommels with concentric sieves is the difficulty of effecting 
 repairs inside, if the plates become worn. This defect is 
 remedied in the trommel figured by fixing on the perforated 
 plates with screw bolts; they can then be taken off quickly 
 and easily. 
 
 II. PROCESSES DEPENDING UPON PHYSICAL 
 PROPERTIES. 
 
 (i) MOTION IN WATER. Many of the more important 
 dressing processes depend upon the rate at which particles of mine- 
 rals fall in water. The velocity of fall depends upon the specific gra- 
 vity and the volume. A piece of galena with a specific gravity of 7-5 
 sinks to the bottom more quickly than a piece of quartz of equal 
 bulk, which has a specific gravity of only 2*6. Nevertheless, 
 if the piece of quartz is large enough, it will fall to the bottom as 
 fast as the smaller piece of galena Particles which have equal 
 velocities of fall, though differing in size and specific gravity, are 
 said to be like-falling or equivalent. 
 
 P. von Rittinger * gives the following table to show the rates 
 of fall of spheres of three minerals differing considerably in 
 specific gravity : 
 
 
 i 
 
 
 
 
 g 
 
 Velocity in Metres after the Lapse of 
 
 SUBSTANCE. 
 
 11 
 
 a 
 
 
 
 
 
 
 020 
 
 13 
 
 isec. 
 
 i sec. 
 
 i*ec. 
 
 i sec. 
 
 2 see. 
 
 Galena . . 
 
 7'5 
 
 mm. 
 16 
 
 0-903 
 
 I -41 1 
 
 1-630 
 
 1-650 
 
 1-650 
 
 Iron pyrites . 
 
 5 <0 
 
 16 
 
 0-825 
 
 1-174 
 
 1-287 
 
 1-293 
 
 1-293 
 
 Quartz .... 
 
 2-6 
 
 16 
 
 0-570 
 
 0767 
 
 O'Soi 
 
 0-817 
 
 0-817 
 
 Galena .... 
 
 7'5 
 
 4 
 
 0-704 
 
 0-814 
 
 0-823 
 
 0*824 
 
 0-824 
 
 Iron pyrites . 
 
 5' 
 
 4 
 
 0-586 
 
 0-643 
 
 0-646 
 
 0-646 
 
 0-646 
 
 Quartz .... 
 
 2-6 
 
 4 
 
 0-383 
 
 0-409 
 
 0-409 
 
 0-409 
 
 0-409 
 
 Galena .... 
 
 7'5 
 
 I 
 
 0-409 
 
 0-413 
 
 0-414 
 
 0-414 
 
 0-414 
 
 Iron pyrites . 
 
 5 - o 
 
 I 
 
 0-321 
 
 0-323 j 0-323 
 
 0-323 
 
 0-323 
 
 Quartz .... 
 
 2-6 
 
 I 
 
 0-203 
 
 0-204 
 
 0*204 
 
 0*204 
 
 0-204 
 
 This table shows that the particles at the very outset have an 
 accelerated velocity, and that the velocity speedily becomes 
 uniform. It also shows that a small sphere of quartz 4 
 
 * Lehrbuch der Attfbereitunc/skundc, Berlin, 1867, p. 178. 
 
DRESSING. 
 
 569 
 
 FIG. 643. 
 
 millimetres in diameter sinks down at almost precisely the same 
 rate as a sphere of galena only i millimetre in diameter. These 
 two particles are therefore like-falling or equivalent. It is 
 evident that if the sphere of galena has a greater diameter than i 
 millimetre it will fall faster than the grain of quartz which is 4 
 millimetres across. Consequently, if a mixture of minerals 
 differing decidedly in density is separated by sifting into lots 
 consisting of particles nearly alike in size, there 
 is no difficulty in effecting a separation by their 
 mere descent through still water. 
 
 This fact may be rendered very plain by a 
 simple experiment. Prepare a mixture of like- 
 sized grains of coal, calc-spar, and galena by 
 sifting the pounded minerals and retaining, for 
 instance, the portion which has no particles 
 more than ^ inch in diameter or less than -j 1 ^-. 
 Put the mixture into a glass tube 4 or 5 feet 
 long and j inch or i inch in diameter, corked 
 at one end (Fig. 643). Fill completely with 
 water and cork the other end ; reverse the tube 
 briskly and hold it upright. The galena will 
 fall to the bottom first, then the calc-spar, and 
 lastly the coal, and the three minerals will form 
 separate layers distinctly marked by their 
 differences of colour. A shorter and narrower 
 tube may be used, but the greater the depth of 
 the water the more accurately can the descent 
 of the particles be watched. 
 
 The experiment may be repeated by reversing 
 the tube, for the galena will soon make up by 
 its high specific gravity for the slightly longer 
 path which it has to travel. 
 
 Though the final velocity attained by a par- 
 ticle of a mineral falling through water depends 
 both upon its volume and its specific gravity, 
 it is nevertheless true that in the early part of 
 the fall the influence of the specific gravity preponderates, and 
 the denser particles take the lead. This appears from the table. 
 Take, for instance, a particle of quartz 16 millimetres in diameter 
 and one of galena of 4 millimetres, which are practically like- 
 falling after the lapse of a second ; at the end of | second, on the 
 other hand, the galena is falling with a velocity 25 per cent, greater 
 than that of the quartz. This fact is utilised in practice, for 
 instead of simply letting the mixture of minerals fall through 
 a certain depth of still water, it is made to undergo a rapid 
 succession of very small falls. In this manner, particles vary- 
 ing in specific gravity can be separated into distinct layers, 
 although they have not been so closely sized as would have 
 
570 ORE AND STONE-MINING. 
 
 been requisite if the separation had depended upon equivalence 
 alone. 
 
 In a few exceptional cases the valuable mineral rises, as it is 
 lighter than water; when a mixture of ozokerite and clay is 
 thrown into water, the waste falls to the bottom whilst the 
 useful substance floats and may be skimmed off at the top. 
 Bitumen, too, comes to the surface when bituminous sandstone is 
 thrown into boiling water and stirred. 
 
 Croll's process for extracting sulphur from rock containing the 
 element in the native state, now abandoned on account of 
 practical difficulties, is another instance of a separation by buoy- 
 ancy. A solution of chloride of calcium was prepared strong 
 enough to have a specific gravity decidedly above 2 ; when the 
 rock was plunged into a hot solution of this kind, the sulphur 
 gradually liquefied, oozed out and rose to the top, leaving the 
 heavier matrix at the bottom. 
 
 A second method of utilising the fall in water consists in 
 subjecting the particles to a current flowing upwards ; by suitably 
 regulating its force, light particles can be carried away and only 
 the heavier allowed to sink. 
 
 Lastly, a third kind of motion is that of small particles car- 
 ried down inclined planes by a thin sheet of water. 
 
 We have now to consider the various machines by which the 
 fall in water is made to effect a separation on a commercial scale. 
 
 1. Simple Fall in Water. 
 
 Keeve or Dolly-tub. This appliance is merely a vat or tub 
 in which the finely divided ore is stirred and then allowed to 
 settle ; it is specially used for the final treatment of fine lead ore 
 and tin ore. The stirring may be done with a shovel whilst 
 the ore is thrown into the water, but more commonly blades, 
 attached to a vertical axle driven by gearing (Figures 644 and 
 645),* are made to keep the mixture of ore and water in a 
 thorough state of agitation. When enough ore has been added, 
 the stirring process (tossing) is stopped and the agitator 
 removed ; the contents of the vat are allowed to settle, while 
 the water is kept in a state of vibration by taps upon the outside 
 from the iron hammer 5, lifted by the cams c, upon the driving 
 shaft. This process of settling is locally called packing; as soon as 
 it is complete, the water is baled out or drawn off by removing 
 plugs in the side, and the deposit is scraped off layer after layer, 
 increasing in richness as the bottom is approached. 
 
 Jigger or Jig. The principal machine for concentrating 
 particles varying in size from i inch to -^ inch is the jigger. 
 The hand-jigger is merely a round sieve which is charged with 
 the crushed ore and then moved up and down in a tub full of 
 
 * Teague, " On Dressing Tin Ore," Proc. Min. Inst. Cornwall, vol. i. 
 
DRESSING. 
 
 water. Each time that the sieve is lowered sharply into the 
 water, the particles are free to drop a short distance, and they 
 gradually arrange themselves in layers, the heaviest at the bottom 
 
 FIG. 644. FIG. 645. 
 
 TOSSING AND PACKING MACHINE.. 
 
 FIG. 646. 
 
 and the lightest at the top. On lifting out the sieve the light 
 waste can be skimmed oft' with a scraper, leaving a well-defined 
 layer of the heavy rich mineral at the bottom, which is removed 
 separately. 
 
 This process of separation can be watched by the aid of a very 
 simple piece of apparatus which the stu- 
 dent can construct for himself (Fig. 646). 
 A model jig^ing-sieve can be made with 
 a cylindrical lamp-glass by fixing on a 
 piece of wire gauze by means of sealing- 
 wax, or by tying on a piece of any net-like 
 fabric. A mixture of crushed coal, calc- 
 spar, and galena, prepared as in the pre- 
 vious case, is placed upon the sieve, and 
 the glass cylinder is now moved down 
 and up in a large tumbler partly filled 
 with water. A distinct separation is soon 
 effected. 
 
 Instead of moving the sieve in still 
 water, it is more common nowadays to 
 make the sieve stationary and to force 
 water up through it with a pulsating action. The particles are thus 
 subjected to a series of repeated lifts and falls, and after the lapse 
 of a little time the charge of crushed ore placed upon the sieve 
 becomes separated into a layer of rich mineral at the bottom, and 
 a layer of light waste at the top ; in the middle there may be a 
 
572 
 
 ORE AND STONE-MINING. 
 
 layer consisting of rich particles with more or less waste material 
 
 attached to them. 
 
 An illustrative model is again easily constructed (Fig. 647) by 
 
 fixing a piece of wire gauze in a lamp-glass, between two rings 
 
 cut from india-rubber hose of suitable diameter, whilst a flexible 
 
 ball syringe supplies the means of pumping water up and down. 
 However, this is not the form in which the jigger 
 
 FIG. 647. is made in actual practice. It usually consists of a 
 box (hutch) divided by a partial partition into two 
 compartments ; in one is fixed a flat sieve s (Figs. 648 
 and 649), which carries the ore, and in the other a 
 piston, p, is made to work up and down by an ex- 
 centric. The mode in which the separation is effected 
 can be watched in a model made out of a U-tube, 
 with a round stick or a test-tube as the piston 
 (Fig. 650). 
 
 The great advantage of these jiggers is that they 
 readily allow a continuous feed of the ore and dis- 
 charge of the products without any stoppages. The 
 ore is fed on by a hopper placed at one end of the 
 machine, or is delivered already mixed with water. 
 Several methods of discharge can be adopted : viz., 
 (a) at the end ; (b) in the centre ; and (c) through 
 the meshes of the sieve. 
 
 (a) With the first kind of discharge, the enriched 
 product lying on the sieve passes out through open- 
 ings at the end of the jigger, and the amount escaping 
 is regulated by an adjustable shutter which enables 
 the size of the outlets to be increased or diminished at 
 pleasure ; the middle product can be drawn off by open- 
 ings placed at a slightly higher level, whilst the waste 
 
 is washed over a sill at the end of the sieve at each pulsation. 
 
 Very often a first sieve simply separates a concentrated product 
 
 and discharges a poorer product on to a second sieve where a 
 
 similar separation is effected. 
 
 (b) With the central discharge method, a pipe is brought up 
 through the middle of the sieve, and the size of the opening for 
 the escape of the concentrated ore is governed by a cylindrical 
 cap, which can be raised or lowered by a screw. 
 
 (c) The discharge through the sieve is specially adapted for the 
 finer products from the crusher, though it is also used for grains 
 up to and even above ^ in. in diameter. The mesh of the sieve is 
 chosen so that the particles under treatment will just pass 
 through, but above the sieve is a layer (bed} of clean ore, or of 
 some substance of about the same density, in fragments too large 
 to drop through. The pulsations of the water cause the usual 
 separation into layers, and the heavy rich particles find their way 
 down through the bed of mineral of like specific gravity and 
 
DRESSING. 
 
 573 
 
 drop into the hutch, whence they can be drawn off through a 
 hole as required. The poorer part passes over a sill at the end 
 
 FIG. 648. 
 
 FIG. 649. 
 
 of the sieve, as a worthless product, or on to a second sieve, so 
 
 that more valuable mineral may be taken out of it. Three or 
 
 four sieves are often arranged in a row in one 
 
 machine, and, by proper arrangement in 
 
 dressing mixed lead and zinc ores, the first 
 
 compartment may be made to yield clean 
 
 galena, the second a mixture of galena and 
 
 blende, tho third clean blende, the fourth 
 
 mixed blende and rock, whilst the greater part 
 
 of the waste material passes over the sill at the 
 
 end. These jiggers, with the discharge through 
 
 the sieve, are commonly known as Hartz jigs. 
 
 The number of strokes per minute, the 
 length of stroke and the thickness of bed 
 depend upon the fineness of the particles 
 under treatment ; the former gradually in- 
 creases, while the two latter decrease as the 
 particles diminish in size. 
 
 The piston of the jigger need not neces- 
 sarily be horizontal. Messrs. Kitto and Paul 
 place it vertically in the jiggers employed at 
 Frongoch mine, Cardiganshire, for treating blende and galena. 
 A and B (Fig. 651) are the two hutches, and C is a partition 
 in the middle. D is the piston working between two plates of 
 
574 
 
 ORE AND STONE-MTNINa. 
 
 iron V V. The piston occupies the whole length of the jig, 
 shown by T (Fig. 652); it is worked by the rod E, guided 
 at F, and passing through a stuffing-box, G. The reciprocating 
 motion is given by a crank M through the connecting-rod L and 
 
 FIG. 651. 
 
 0123 56 Feet 
 
 lever H, which traverses the head of the piston-rod I. The crank 
 has a long loop, which enables the stroke to be varied. The same 
 end can be attained by an excentric with a slot, which allows the 
 excentricity to be altered at pleasure. N shows where the ore is 
 fed on, and is the place of discharge of the wasbe or impoverished 
 
 FIG. 652. 
 
 ore. S is the sieve, and P P are holes with plugs manipulated by 
 handles not shown in the figures, by which the concentrates 
 which pass through the sieve are drawn off. R is the pipe bring- 
 ing in clean water. 
 
 2. Upward-current Separators. 
 
 We must now pass on to the second method of utilising the 
 motion of minerals in water, viz., by subjecting them to an 
 upward current; and here it may be remarked that the con- 
 
DRESSING. 
 
 575 
 
 tinnous jig to a certain extent produces an action of this 
 kind, for the light waste, brought to the top by the pulsating 
 movement, is finally carried away by the outflow of the fresh 
 water. 
 
 Upward-current separators are usually inverted pyramidal or 
 conical boxes with water under pressure brought in near the 
 bottom. A stream of ore and water is fed in at the top, 
 some of the heavier particles sink and make their escape with a 
 portion of the water, at or near the bottom, whilst the lighter 
 grains are carried over the edge of the box. A separator of this 
 
 FIGS. 653 and 654. 
 
 2 MtTKt* 
 ~9 FCET 
 
 kind simply extracts a number of like-falling particles, and 
 the product may require further treatment before a sufficient 
 degree of concentration is obtained. 
 
 Jacome"ty and Lenicque's Separators. Figures 653 and 
 654 represent Jacome'ty and Lenicque's pyramidal separator with 
 six compartments, A, B, C, D, E, F, which make seven cate- 
 gories from pulp with all its particles under i mm. in diameter. 
 Each compartment is merely a box in the form of an inverted 
 pyramid, and for convenience of transport, the machine is made 
 in three separate castings, which can be easily bolted together, 
 as shown at R and S. Pipes bring down water from the main 
 G H, and the amount supplied to each division can be regulated 
 by a cock ; the water strikes a little plate attached to the end 
 of the pipe and rises up. 
 
576 
 
 OEE AND STONE-MINING. 
 
 The pulp is fed on at J and escapes at K. Particles which can 
 overcome the upward current are discharged continuously through 
 a nozzle at the apex of each pyramid. These nozzles are shown 
 at L, M, N, O, P, Q ; they are easily detachable, and can be taken 
 
 FIG. 655. 
 
 crew \nut with handle 
 
 off during the progress of the work, if by any chance they 
 become choked. 
 
 Though separators of this kind are usually employed for the 
 treatment of fine sand and slime, they are occasionally applied to 
 comparatively coarse stuff. The separator shown in Figures 655 
 and 656 is used at Frongoch mine, Cardiganshire, for treating 
 an ore consisting of blende and galena, mixed with slate, just as it 
 leaves the rolls, after having been crushed fine enough to pass 
 
DRESSING. 577 
 
 through a sieve with 1 2 holes per square inch (3 holes by 4 holes). 
 The coarse goes to the jigs, the fine to the buddies. It is an 
 inverted wooden cone A, which can be more or less com- 
 pletely closed at the bottom by a plug B, controlled by a handle 
 C. The cone stands upon a wooden box D, which receives 
 water under pressure from a pipe E, and is provided with 
 a discharge valve F, a mere flat plate of iron, working on a 
 pin, which can be pushed sideways so as to close the orifice 
 partially or entirely. Inside the wooden cone there is a sheet- 
 iron funnel G-, which receives the stream of ore and water 
 from a launder H, and causes it to descend to the level I. 
 There it meets with the upward current of clean water, and a 
 separation is effected. The coarse and heavy particles which can 
 overcome the stream pass into the box below, and flow out con- 
 tinuously at F, while the fine and light particles are mastered by 
 the current and carried over the top edge of the wooden cone, 
 which is surrounded by a circular launder. By regulating the 
 upward current of clean water and the size of the discharge 
 orifice, the separator can be adjusted to the requirements of any 
 particular case. 
 
 Lockhart's Automatic Gem Separator. In this machine 
 the particles of minerals fall into a current of water ascending in 
 an annular space, purposely made narrow in order to prevent 
 eddies, which would interfere with the desired results. The 
 velocity of the current can be regulated by stop-cocks, and 
 arranged so that only the denser of any like-sized particles shall 
 be able to overcome it and sink. Its primary object is to treat 
 clean-washed concentrates from gem-bearing gravel after a careful 
 preliminary sizing by screens. 
 
 Siphon Separator. A most successful application of an 
 upward current of water is in the machine known as the siphon 
 separator, though its action is not based upon the principle of tho 
 appliance from which it takes its name. 
 
 It consists of a rectangular box (Figs. 657, 658, and 659),* 
 made of sheet iron or wood with a partition, dividing it into two 
 chambers B and E. The front one B resembles a pyramidal 
 separator, receiving an upward current of fresh water from the 
 adjacent compartment E and an orey stream from the launder 
 G, the continuation of which carries away the light waste. The 
 compartment E has a partition , dividing it into two parts : A, 
 which receives a supply of fresh water by means of the pipe a, 
 and (7, which has the regulating float s. To prevent shocks and 
 eddies, the water does not fall directly into E, but first passes 
 through holes in the partition u. The precise position of the 
 float s can be altered at pleasure by the rod /, which connects it 
 to the lever h, movable about the fulcrum i attached to the 
 
 * Heberwiische des Mechernicher Bergwerks-Actien-Vereins, B. u.h. Z., 
 iSS6, p. 476. 
 
 2 o 
 
573 
 
 ORE AND STONE-MIXING. 
 
 upright bar t. The travel of the lever is controlled by moans of 
 the rod g. A light rod e carrying the outlet valve is attached 
 to the lever at d ; this valve is set in the middle of a pyramidal 
 sieve bottom 6, and governs the discharge into the pipe q, which 
 
 FIG. 6;'; 
 
 FIG. 658. 
 
 leads to the outlet orifice r. The object of these arrangements is 
 to obtain a self-regulating discharge, the action of which is 
 very simple. As the ore-bearing stream passes along over the 
 box B, the heaviest particles overcome the upward pressure 
 of the ascending current and drop ; if the valve is shut, they 
 
DRESSING. 579 
 
 accumulate upon the sieve, and prevent the passage of some of 
 the water through it. The obstruction causes the water in the 
 chamber C to rise, the float ascends at the same time, and in so 
 doing lifts up the valve and allows the discharge of the grains 
 of ore into the pipe q. The float then sinks, the valve goes down, 
 another little deposit of ore causes an obstruction and the process 
 is repeated. 
 
 These separators are some of the principal machines employed at 
 Mechernich for the treatment of the friable lead-bearing sandstone ; 
 in fact, there are no less than 124 of them in use. They are 
 remarkable for their simplicity and for the large amount of stuff 
 that they will treat. The quantity of broken sandstone which 
 can be successfully passed through one machine per hour is from 
 270 to 300 cubic feet (8 to 9 cubic metres). Sometimes two or 
 three of these machines are placed one after the other, the second 
 receiving the overflow of the first, and the third the overflow of 
 the second. 
 
 The quantity of water required is somewhat large viz., 9900 
 gallons (45 cubic metres) per hour ; but at Mechernich it is used 
 over and over again, after the fine matter in suspension has been 
 allowed to settle. 
 
 3. Separation by Water flowing down Planes. 
 
 We lastly have to deal with the third manner of utilising the 
 motion of mineral particles in water, that is to say, allowing 
 them to be carried down inclined surfaces by a stream of water. 
 
 Two classes of appliances are used : those in which the deposit 
 is cleaned off as soon as a thin layer has settled down, and those 
 in which the deposit is allowed to go on forming until it has 
 attained a thickness of at least several inches or a foot. 
 
 (i) The first class includes various kinds of plane and conical 
 tables, certain percussion tables, and the travelling belts. 
 
 PJane Tables. Plane tables, often called "frames," and 
 sometimes, but incorrectly, called " buddies," are slightly inclined 
 rectangular surfaces of wood down which the pulp flows in a 
 regular stream. An even flow over the whole width of the table 
 is secured by first passing the stream over a head-board, which 
 divides it into a number of little rills. The strength of the 
 current depends upon the quantity of water, and upon tho 
 inclination given to the table. These are arranged so that some 
 of the mineral under treatment will settle down and resist the 
 action of the water, which is always tending to carry it on 
 further. After a deposit of this kind is formed, clean water is 
 often allowed to run down over the table to carry off any light 
 particles intermixed with the heavy ore, and its action is aided 
 by brushing lightly with a. broom. The deposit is then washed 
 off and collected in a tank for further treatment. 
 
580 ORE AND STONE-MINING. 
 
 Where the mineral to be treated is poor, the tables have to be 
 worked with as small an expenditure of labour as possible ; and 
 
 FIG. 660. 
 
 tNS.12 01 234-5678 
 
 FCET 
 
 DtCIMETRtS '0 
 
 FIG. 661. 
 
 J-anyiJudinaZ Section,. 
 
 the device adopted in Cornwall is explained by Figs. 660 to 662.* 
 A is a launder bringing the pulp, which flows down over the head- 
 Ferguson, " On the Mechanical Appliances used for Dressing Tin and 
 Copper Ores in Cornwall," Proc. Inst. M, JE., 1873, p. 130. 
 
DRESSING. 581 
 
 board B on to the inclined surface of the table, leaving upon 
 it, in virtue of their high specific gravity, some of the heavy 
 particles of tin ore, and carrying the lighter refuse into the 
 launder C. While this action is proceeding, the clean water 
 launder E is filling the two V-like troughs D and D'. When 
 these are full, they tilt over (Fig. 662) and discharge their contents 
 suddenly on to the table, washing off the deposit. The troughs 
 D and D', on turning over, carry the bar H H forwards, and 
 thus lift the flaps at F and F', so that the upper and richer 
 part of the deposit is washed into the launder F, the lower and 
 poorer part into F'. As soon as the troughs have discharged 
 their water, they are brought back into their original position by 
 the simple cataract G, and the process is repeated. 
 
 Round tables are bluntly conical, convex or concave surfaces; 
 with the former the pulp is fed on at the centre and runs down to 
 the circumference ; with the latter, the direction of flow is reversed. 
 The tables are made of wood, planed cast-iron, or cement ; the 
 wooden tables may be plain or covered with india-rubber. They 
 are stationary or revolving. 
 
 An excellent stationary table is that of Linkenbach* (Figs. 663 
 and 664). The table itself, a, is made of masonry with a smooth 
 surface of cement ; b is an upright shaft, which carries the pulp-dis- 
 tributor and the pipes supplying water for cleaning and for wash- 
 ing off the deposit ; it is set in motion by the worm d and wheel 
 c. Two of eight radial arms, borne by a centre-piece, are indicated 
 by e e ; they carry the apron g, the clean water pipes, h, h, h, the 
 position of which can be regulated at pleasure, and the washing- 
 off pipe i. The clean water is brought in by the circular box k, 
 rotating with the arms e, and supplied from the pipe I ; the pulp 
 is delivered through the pipe ra, which passes along the conduit n 
 under the table into the inner ring o' of tiie adjustable dis- 
 tributor o. The distributor is constructed so as to deliver pulp at 
 o" and clean water at o'" ; p p are pipes bringing down clean 
 water from the rotating launder k, and q', q", q'" aro three 
 concentric gutters, by which the various products are led away. 
 The innermost gutter takes the waste " tailings," the middle one 
 the mixed product, and the outer gutter the clean concentrate. 
 The two latter products are conducted each into its proper channel 
 by the apron g, which is made of sheet zinc. 
 
 The mode of action of this table is easily understood. The 
 distributor is constantly feeding on slime by the part of its circum- 
 ference r o s (Fig. 664) ; a deposit forms on the table, whilst the 
 lighter tailings run off into the gutter q', which is freely open to 
 them in the absence of the apron. As soon as the feeding part of the 
 distributor has passed, clean water begins to flow down over the de- 
 posit from the trough o'", carrying off the middlings into the gutter 
 
 * Linkenbach, Die Auflereitung der Erze, Berlin, 1887, p. 101, and plate 
 xvi. 
 
532 
 
 OEE AND STONfrMINING. 
 
 FIG. 664. 
 
 GROUND PLAN 
 
 SCALE* 
 
 7MC.TRLS 
 
DRESSING. 583 
 
 g", and having its action aided by the washing-off jets h. There now 
 remains on the table nothing but a clean concentrate, and this is 
 washed off into the gutter q" f by the jets i ; r f is a launder carry- 
 ing away the waste ; r" conducts the middlings to a settling pit 
 A, and the concentrate escapes by a similar launder r'" into B ; 
 z is a wire rope for driving a second table. 
 
 An easy way of realising the mode of action of this table is to 
 divide it mentally into three portions viz., the sector from t to v, 
 which is receiving the slime ; the sector from t to w, from which 
 the middlings are being washed off; and lastly, the sector from v 
 to w with the clean concentrate, which yields to the jets issuing 
 from i, and passes over the apron into the outer gutter q'". 
 
 Where the amount of space is limited, Linkenbach places three 
 tables on the same central shaft ; but the economy of space and of 
 original first cost is accompanied by less easy supervision. 
 
 The mode of action of round tables is very often just the 
 reverse of what has been described ; that is to say, the table 
 revolves and the distributor is stationary. Linkenbach points 
 out that a revolving table is necessarily subject to vibrations, 
 which must interfere with the evenness of the flow down the 
 inclined surface, whilst the fixed table with a travelling distributor 
 is free from influences of this kind and is likely to work more 
 regularly. 
 
 Nevertheless, in spite of this objection, revolving round tables 
 may be seen doing good work. The table represented in Figs. 665 
 and 666 is one designed by MM. Jacomety and Lenicque. A is 
 the head-board or distributor which feeds the table B with a 
 stream of the fine slime ; the table is made of arms of T-iron, 
 radiating out from a cast-iron centre-piece C, which support a 
 light covering of planks. Over this is stretched sheet india-rubber, 
 which forms a smooth surface, free from any liability to warp 
 and get out of shape. The table is set in motion by the vertical 
 shaft D, driven by the wheel G and worm II. L L are various 
 pipes bringing clean water, supported by rods N N, and capable 
 of being placed in any suitable position. M M are pipes which 
 wash off the deposit from the table; they are held up by 
 standards N' N', which can be shifted about at pleasure. K is a 
 circular launder round the table, with discharge holes t t, and 
 movable wooden partitions s, s', s", s", s"" ; lastly, the pipe O sends 
 out jets of water which clean off everything remaining upon the 
 table. If the table is supposed to be moving in the direction of the 
 arrow, it is evident that products of different kinds will be washed 
 off at different periods of the revolution, and that towards the 
 end nothing will remain on the table but the heaviest particles. 
 By suitably arranging the amount of feed and the position of the 
 different washing-pipes, the table can be made to give clean ore, 
 waste, and intermediate products ; the latter are passed over the 
 same or a similar machine once more. 
 
5*1 
 
 ORE AND STONE-MIX :> 
 
 working surface 4 feat n inches (130 m,) long; it ak one 
 
 iWQMKMMi in ^j iBwnutes% T^^umng less tnan * ^ u^pc %a wortc K 
 TW qwantky ol water us^d is about *6 gaUoos (uo fibres) per 
 minute aattfetoUawRtNat few eta* tea* of sHae in ten 
 
 and tfe table wffl few* fam 5 to* 
 As it is wfci of cu&t 
 
 it is 
 
 (Fifr 
 
 fCHlT( 
 
 667) 
 corners A B C P. receiving 
 
 led by ta 
 
 .A. 
 
 of orey w>t- S is f edo* to the corner 
 runs down from oUm l^ad bo>f di H H H. Brmeooisof CUBS upon 
 a involving shaft^ the taOOe is po^Mdoot in tiie direction of the 
 mrrow,andit ^ is then driv^bckbyaspru^>3o U^ AroBBfri*wi 
 B strike against OM Immpn^btock L. The fight ptrtkfes twral 
 down the Ubie mocd faster than the heavy ones, and 
 str&^iit coarse, leA\v the table aft K; 
 
UK! 
 
 585 
 
 the heavy and richer particles remain on the table, subject to the 
 inOuence of U< <ws, for a much longer time, and traveling 
 
 along a curved jaih r< .'!) the bottom at F. An intermediate 
 product i discharged at G. The exact degree of n 
 poorness ran ben-gulat'-d by poii.l-ih. ; trips of wood which ran 
 be turned BO as to divide the stream of ore and WM< 
 thought most desirable. The great advantage of this machine 
 
 the old percussion frame is its continuous action. 
 Travelling Belts. We now come to the travelling belts, of 
 which there are many varieties. An early form was that of 
 Brunton,* an endless belt of canvas acting in the same way as 
 007. 
 
 FIG. 668. 
 
 the now favourite Frue-vanner, Rave that there was no shake 
 sideways. In fact, the latter machine is regarded by some as an 
 improved form of the Brunton cloth. 
 
 The Frue-vanner (Fig. 668) is an endless band of india-rubber 
 <lot h, 4 feet wide and 27 feet long, with an upper working surface 
 of about i 2 feet in length. The belt is supported by a frame with 
 a number of small rollers on which it travels easily, and it is 
 driven nlowly in the direction of the arrows by the upper 
 end roller shown in the figure. The small roller by the side 
 of the large one, which dips into the tank, serves for 
 tightening up the belt when required. The whole frame 
 carrying the belt receives a motion sideways from three little 
 cranks upon a small shaft running parallel to its length. The 
 pulp is fed on by the head-board A, and clean water by 
 another B. The natural path of the particles Is down the 
 inclined belt, but those which can resist the action of the 
 
 * Sopwith, " The Dressing of Lead Ores," Proc. Inst. C. E. t vol. xxx., 1870, 
 p. 112. 
 
586 ORE AND STONE-MINING. 
 
 stream of clean water at B, go over the top end, and are washed 
 off as the belt passes through the tank. The poor stuff is 
 discharged into the waste launder at the other end. The degree 
 of concentration can be regulated by the slope and speed of the 
 belt and the strength of the streams of ore and water. The 
 Frue-vanner has the disadvantage that it makes only two classes, 
 rich and poor, without any intermediate product. 
 
 The success of the Frue-vanner has naturally brought a number 
 of somewhat similar contrivances into the market. The Embrey 
 concentrator may be likened to a Frue-vanner, with a longitudinal 
 instead of a lateral shake. 
 
 The Woodbury ore concentrator is made up of several narrow 
 belts each with its own flanges, instead of there being one broad 
 band. The object of this arrangement is to prevent uneven- 
 ness of flow, for if strong, irregular currents are formed in the 
 centre of the belt, they may carry away good ore into the waste 
 launder. 
 
 Stem's endless belt, which has been improved by Bilharz, has a 
 totally different mode of action. It resembles the Rittinger 
 percussion table in its manner of effecting a separation, but the 
 work is done on a travelling belt instead of an unchanging sur- 
 face. Stein's machine* (Figs. 669, 670, and 671) is a rectangular 
 frame a, suspended between two posts p, by rods i, at the four 
 corners, so that it can swing in the direction of its long side. The 
 inclination of the frame can be altered at pleasure, by the handle 
 attached to the cross-beam I, which works upon the screw e, but 
 the long side always remains horizontal. The frame is drawn slightly 
 out of position by cams r, acting upon the lever ra, and as soon as 
 it is released it is pulled back against a bumping-piece 2, by a 
 spring n. The frame has two large rollers c c, and three small ones 
 underneath, which carry an endless belt of india-rubber jf, the upper 
 part of which is further supported by the flat bed of boards b. 
 The belt slides over this bed, and is prevented from sticking to it 
 by a constant flow of water, supplied by the pipe g, along narrow 
 diagonal grooves. One of the end rollers is made to revolve and 
 carries the belt with it. The pulp is fed on by a head-board k, 
 and clean water is turned on through holes in the pipe o. The 
 direction of travel of the belt is indicated by the arrow. The 
 concentrating action is like that of a Rittinger table. The 
 lightest particles run down at once, and leaving the belt at the 
 right-hand end of the table, fall into the first compartment of the 
 launder g, whilst the heaviest remain on the table much longer, 
 and are finally discharged at the left-hand end. Intermediate 
 products run off in the middle. 
 
 (2) The second set of appliances includes the buddies and 
 ordinary percussion tables. 
 
 * Blomeke, " Ueber den Stein'schen Plannen-Stossherd," B. u. h. Z. 
 1891, p. 69. 
 
DRESSING. 
 
 5S7 
 
 Buddies. The hand-buddle is a rectangular wooden box with 
 a sloping bottom. A stream of pulp is fed in by a head-board at 
 
 FIGS. 669 and 670. 
 
 1 
 
 1 
 
 the upper end and gradually forms a deposit on the floor of the 
 buddle. A boy with a broom keeps the surface of the sediment 
 even, so as to ensure regularity of action. After a thick deposit 
 
588 
 
 ORE AND STONE-MINING. 
 
 has accumulated, it is dug out in sections, which decrease in rich- 
 ness from the upper end (head} to the lower end (tail). 
 
 Round buddies bear the same relation to hand buddies that 
 round tables do to hand frames. They may be concave or 
 convex, but the latter are the more common. 
 
 The convex round buddle (Figs. 672 and 673) is a circular pit* 
 with a truncated cone, or head, of varying size in the centre, and a 
 bottom sloping towards the circumference. The orey stream, A, 
 
 FIG. 672. 
 
 FIG. 673. 
 
 falling over this head runs down gently, depositing the heaviest 
 particles near the top, the lighter ones further down, while the 
 lightest of all flow away at C. The surface of the sediment is 
 kept even by the revolving brushes D. This machine may be 
 compared to a number of hand-buddies arranged radially round 
 a centre. The deposit which is formed is dug out in rings of 
 varying richness. 
 
 The concave buddle is a circular pit with the bottom sloping 
 
 * Henry T. Ferguson, " On the Mechanical Appliances used for Dressing 
 Tin and Copper Ores in Cornwall,'"' Proc. Inst. AJech. Eng. t 1873, plate xli., 
 and p. 124. 
 
DRESSING. 589 
 
 towards the centre. The stream of ore is fed all round the cir- 
 cumference, and runs inwards towards the middle, where the 
 lightest particles escape. The rich head is, of course, near the 
 circumference. 
 
 Ordinary Percussion Table. The ordinary percussion table, 
 though rarely if ever seen in this country, is still employed in 
 Germany and regarded with favour. Those familiar with the 
 hand-buddle will understand what it is like, if it is described as a 
 swinging hand-buddle which is continually being bumped at the 
 upper end. It is a shallow rectangular sloping wooden or iron 
 tray suspended from the four corners, so that it can move back- 
 wards and forwards in the direction of its length, and as soon as 
 it has been pushed out of position by a cam, it is at once forced back 
 by a spring against a fixed wooden bumping-block at the upper 
 end. The pulp is fed on at the upper end by a head-board, 
 and the lightest particles run off at the lower end, which has no 
 rim, whilst the heavier and richer ones form a gradually thickening 
 layer upon the bed. When sufficiently thick, the deposit is 
 shovelled off in sections varying in richness as they do in a 
 buddle. The bump assists in making the particles settle, just 
 as it does in the " keeve," and at the same time, in virtue of the 
 vis viva acquired during the backward stroke of the table, grains 
 of ore are constantly being thrown up a little, as they are with 
 the German hand- washing dish. 
 
 Machines of this class have two grave defects : careful watching 
 is necessary, in order to keep the surface of the deposit perfectly 
 even ; otherwise gutters are formed, down which the water runs 
 with too great a velocity, carrying away rich ore or depositing it 
 near the tail end when it ought to have subsided at the head. 
 Secondly, the deposit has to be shovelled off, and the parts 
 requiring further treatment have again to be mixed with water 
 and brought into a proper consistency, before they can flow on 
 to other machines. In spite of these drawbacks, buddies and 
 percussion tables are still largely employed. 
 
 (2) MOTION IN AIR. In countries where water is scarce, 
 or where the valuable mineral is specially liable to be affected 
 or carried off by water, engineers have long desired to employ 
 air as the medium in which the concentration should be effected. 
 
 Three kinds of machines are used : the pneumatic jig, the fan, 
 and the centrifugal concentrator. 
 
 Pneumatic Jig. The pneumatic jig resembles the hydraulic 
 jig in principle ; that is to say, particles of minerals varying in 
 specific gravity can be separated if they are lifted and then 
 allowed to fall again, provided that the sizes of the grains do not 
 differ too widely, and that the specific gravities do not approach 
 too closely. The principle will be most easily grasped if the 
 student constructs a very simple model (Fig. 674). A piece of 
 glass tube with the upper end covered by net or muslin is 
 
590 
 
 ORE AND STONE MINING. 
 
 inserted into a slightly larger tube. The lower end is then 
 connected to an india-rubber pump, such as is used with scent 
 diffusers. Pour a mixture of like-sized grains of galena and sand 
 on to the sieve, and give the pump a succession of gentle squeezes. 
 Puffs of air are sent up through the sieve, and the two 
 FIG. 674. minerals arrange themselves as shown, the galena below, 
 and the sand above. 
 
 By using a bed of fine shot, jigging through the 
 sieve may be carried out, the action resembling that of 
 the Hartz sand-jigs. 
 
 Krom's* pneumatic jig, which is in actual use for 
 treating silver ore, is a wooden chest in which a fiat 
 vane moving backwards and forwards sends a number 
 of rapid pufts of air through a bed of fine ore, resting 
 upon a sieve made of short upright tubes of wire cloth, 
 with small spaces between them. The fine ore is fed 
 in from a hopper on one side of the long narrow sieve. 
 The repeated falls bring about a separation, and the 
 light waste passes over the edge of the sieve opposite 
 to the feed-hopper, whilst the concentrate sinks down 
 through the interspaces between the sieve tubes into 
 a reservoir, from which it is drawn off gradually by 
 a fluted roller. As this reservoir is always kept full, 
 the rate of discharge and degree of concentration can 
 be varied by altering the speed of the roller. 
 
 Fans. A fan is used in connec- 
 tion with some grinding machines 
 in order to draw off the powdered 
 mineral, and, in dealing with a 
 homogeneous substance, the amount 
 of suction can be regulated so as not 
 to draw the mineral out of the 
 machine until it has been sufficiently 
 
 pulverised. If the dust-laden air is then discharged into a large 
 chamber, the coarsest particles will settle down first, whilst the 
 finest will be wafted to the far end. 
 
 As an instance of fan-action, the dressing of phosphate of lime 
 may be mentioned. Some of the phosphate of lime which is 
 ground between millstones in France is not passed through any 
 sieve at all ; a fan is adjusted so as to draw it away from the mill 
 sufficiently fine to be put into sacks at once. Tests are made 
 from time to time to see that the product is properly ground, 
 for it is sold with the guarantee that not more than a certain 
 percentage shall be too coarse to pass through a given sieve. 
 
 Another example may be taken from some of the fuller's- 
 earth dressing establishments. The earth is ground in an 
 
 * Gallon, "Lectures on Mining," Paris and London, 1886, vol. iii.,p. 104 
 and Atlas, plate civ. 
 
DRESSING. 591 
 
 Askham mill and forced by a fan into a chamber some 50 feet 
 long by 10 feet wide, where it drops upon the ground ; the deposit 
 is shovelled away afterwards in sections, which are finer and finer 
 as one goes away from the orifice through which the dust enters. 
 The requirements of different customers can thus be satisfied. 
 
 When a fan is employed for drawing off the fine product from 
 a mill or crusher, it likewise serves the useful purpose of pre- 
 venting the atmosphere of the works from being polluted by 
 noxious dust. 
 
 Centrifugal Concentrator. These concentrators are based 
 upon the fact that when bodies of equal volume are whirled round, 
 the centrifugal force developed is proportional to their densities. 
 Therefore, if the like-sized particles are projected by centrifugal 
 force from a machine, the denser ones, with their larger store of 
 energy, will be better able to overcome the resistance of the air 
 than those which are specifically lighter, and will consequently 
 travel further. The truth of this can be made manifest with a 
 child's top. Spin the top in a saucer or dish raised a little above 
 the table, previously covered with a sheet of paper or cardboard, 
 and feed on to its flat upper surface a thin stream of finely 
 powdered galena and sand, which has passed through a sieve with 
 100 holes to the linear inch and refused to pass the 120 mesh. 
 The particles will be whirled off, light sand will drop close to 
 the saucer or even into it, whilst the heavy galena picks up a 
 larger amount of energy from the spinning-top and flies further 
 away before settling. By brushing 
 up the dust concentrically, the FlG> 
 
 effect will be apparent. 
 
 The Clarkson-Stanfield concen- 
 trator (Fig. 675) works preciselv in 
 this way. B is a distributor, which is 
 made to revolve rapidly by its spindle 
 C. The hopper A supplies it with 
 finely powdered and carefully sized 
 ore, which escapes by a number of radial holes. The dotted lines 
 show the paths taken by the particles of mineral, which drop into 
 a series of concentric troughs from which they can be swept by 
 revolving brushes into discharge-spouts. 
 
 In order to work successfully, the ore must be very carefully 
 separated by screening into particles of approximately the same 
 volume. The machine is new, and has yet to bear the test of 
 actual practice on a large scale at mines, but it is worth notino- 
 that a similar appliance is used at mills * for freeing semolina 
 from bran and dust. The Pape-Henneberg f ore concei.tra'tor is 
 identical in principle with that of Clarkson and Stanfield. 
 
 A disadvantage of all pneumatic dressing is that the ore has to 
 
 * Spon's Dictionary of Engineering, London, 1873, vol. vii., p. 2499. 
 t B. u. h. Z., 1893, p. 191] 
 
592 ORE AND STONE-MINING. 
 
 be very thoroughly dried, for otherwise the particles stick together 
 slightly and counteract the action of the forces which should effect 
 the desired separation. 
 
 (3) DESICCATION. Various reasons call for the drying of 
 minerals. Sometimes the mineral cannot be ground until it is 
 freed from moisture ; in other cases drying is advisable in order to 
 save the payment of carriage upon a useless ingredient ; it is like- 
 wise necessary before a mineral is roasted in furnaces, or passed 
 through certain magnetic separators, and, as has just been 
 remarked, it is indispensable when the subsequent treatment is 
 effected by a pneumatic process. 
 
 Drying may be carried on in one of the following ways : 
 
 a. By exposure to the air. 
 
 b. By open fires. 
 
 c. On open floors or pans. 
 
 d. In enclosed stoves or kilns. 
 
 e. By filter presses. 
 
 a. Air Drying. Simple exposure to the action of the 
 atmosphere, under a light roof as a protection from occasional 
 showers, is quite sufficient for the purpose of drying many 
 minerals, provided that the weather is fine. China clay and 
 ochre are sometimes dried in this way. The roughly cubical clods 
 are piled up one above the other, allowing free access of air, and, 
 if the weather is favourable, a sufficient amount of moisture 
 evaporates naturally to render the mineral fit for the market ; 
 but a wet season sadly interferes with the work, frost will cause 
 the clods to crumble, and artificial drying often becomes necessary 
 in order to satisfy the demands of customers. 
 
 In Chili the crystals of nitrate of soda are soon dried perfectly 
 by exposure to the atmosphere. 
 
 b. Open - fire Drying. The phosphate of lime dug or 
 dredged in South Carolina is sometimes dried by heaping it upon 
 piles of wood which are set alight. 
 
 c. Drying on Heated Open Floors. Heated floors are em- 
 ployed in drying barytes, fuller's earth, and phosphates previous 
 to grinding, other minerals previous to roasting, and china clay 
 previous to sale. 
 
 Fig. 676 shows a Cornish " dry" for china clay.* The letters I I 
 represent the " settling tanks " or stone-lined pits into which the 
 clay is run, in the form of a thin mud, after the coarsest particles 
 of the decomposed granite have been separated. Here it forms 
 a sediment of the consistency of thick cream, which is trammed 
 to the " dry," after the water has been drawn off. The drying- 
 house is composed of the dry proper m m, and the storing sheds 
 or " linhays," o o. The floor of the dry is made of large fire-clay 
 tiles, which cover a number of flues, each about 14 inches wide, 
 
 * Collins, " The Hensbarrow Granite District," Truro, 1878, p. 20. 
 
DRESSING. 
 
 593 
 
 leading away from the fireplaces, s s. The tiles are 5 or 6 inches 
 thick over the fires, where the heat is greatest, and the thickness 
 is reduced to 2 J or 2 inches at the other end of the building. The 
 clay is trammed in along the road 1 1, and tipped on to the floor or 
 " pan " m m, until it forms a layer 9 inches thick at the fire-end 
 and 6 inches thick at the stack-end. The clay at the fire-end 
 is dried in 24 hours ; it is cleared off and stored in the linhay 
 o o f and another charge of wet clay trammed in ; the further 
 the clay is from the fire, the longer it takes to dry, and at the 
 stack-end, the " pan " can be cleared and re-loaded only twice 
 or three times a week. It appears that much more of the 
 
 FIG. 676. 
 
 moisture soaks down through the tiles and is carried away as 
 steam by the flues, than evaporates from the surface of the pan, 
 and for this reason the tiles are made as porous as possible. 
 
 The open floors used for drying phosphate of lime in the 
 North of France previous to grinding have the bed made of 
 sheets of iron. The plates are about one metre square and 
 are laid upon a series of parallel flues formed of little walls one 
 brick thick. The floors are often about 20 metres long and 4 
 metres wide. In order to accelerate the process of drying the 
 sandy phosphate is shovelled over from time to time by men, but 
 the cost of labour can be reduced by using Arnett's mechanical 
 hoe which performs the same office. It is a frame stretch- 
 ing across the whole width of the floor, carrying a single 
 row of broad blades or spades, which can be inclined at any 
 
 2 P 
 
594 ORE AND STONE-MINING. 
 
 desired angle to the bed; it is drawn backwards and for- 
 wards by machinery. The blades pass into the layer of phosphate 
 on the floor, heap up the stuff in front of them, and cause the 
 particles to mount up, and then fall over on to the bed again. 
 Each time the hoe passes along, the stuff is shifted forwards a 
 little, so that when the frame arrives at the end of its course, it 
 pushes off a portion of the charge, which is now dry enough for 
 milling, as it has travelled along the full length of the bed. As 
 the inclination of the blades can be altered, the rate at which the 
 stuff is carried forwards can be regulated so as to prolong or 
 shorten the drying process, as required. The machine is made 
 to reverse its direction of travel automatically, but it does no 
 stirring on the return stroke. 
 
 Thelen's drier is an open semi-cylindrical iron pan heated by a 
 fire below, in which the charge is stirred by knives moved me- 
 chanically. 
 
 d. Stoves and Kilos. The number of kinds of enclosed stoves 
 and kilns employed for drying minerals is very great ; and it is 
 especially in the case of brown coal* that the ingenuity of in- 
 ventors has been exercised to devise means of getting rid of 
 moisture. However, as the subject of brown coal does not belong 
 to this work, the special stoves made use of cannot be dealt with 
 at length ; still it is right that they should be mentioned, as some 
 of them could be used for other minerals. 
 
 With such a large number of drying stoves, it is absolutely 
 necessary that there should be a classification of some kind, for 
 otherwise the student runs the risk of being confused. 
 
 It is perhaps most convenient to classify them first of all accord- 
 ing to the mode of heating, and then make a further subdivision 
 according as kiln or furnace is stationary or revolving. 
 
 Enclosed Kilns and Stoves. 
 
 Mode of Heatir.g. Kind of Drying Surface. Name of Drying Stove. 
 
 /American Phosphate 
 kiln. Fullers' earth 
 
 (Stationary . -L kih V 4 
 
 Direct fire ... Krorn's stove. 
 
 iKiebeck's stove. 
 
 (Revolving 
 
 Direct fire and hot air 
 
 Brunton's furnace. 
 Euelle's stove. 
 
 Rowoldt's stove. 
 Stationary Steam stove. 
 
 Schulz's stove. 
 
 Hot air ... Stationary 
 
 { Stationary 
 
 Steam - I Revolving 
 
 Hot air and steam ... Stationary Jacobi's stove. 
 
 American Phosphate Kiln. The kilns employed for drying 
 phosphate of lime in South Carolinaf after washing are simply 
 
 * Vollert, Der Braunkoldenbergbau im Oberberfjamts-Bezirk Halle und in 
 den angrenzenden titaaten, Halle a. d. S. 1889, p. 249. 
 
 t Benedict, "Mining, Washing, and Calcining South Carolina Land 
 Fho-phate, Eng. Min. Jour., vol. liii., 1892, p. 349, 
 
DRESSING. 
 
 595 
 
 rectangular chambers, built of brick and roofed with wood. The 
 whole of the bottom is covered with a pile of wood, on to which 
 the wet phosphate is tipped from barrows. The wood is set alight 
 and flues supply it with air for combustion. Each kiln holds 
 from 1000 to 1200 tons of phosphate; the fire burns out in from 
 two to five days, and the phosphate is then ready for export. 
 
 Fullers Earth Kiln. The fullers 7 earth kiln may be taken as 
 another example of the first class. It is a brick or stone build- 
 ing about 36 feet long and 15 feet wide, with an arched roof of 
 brick (Fig. 677) or a sloping roof of slate. About 9 feet above the 
 bottom is a floor a, made of cast- 
 iron plates full of holes about ^ 
 inch in diameter, underneath 
 which are two sets of sloping 
 shelves, made of sheets of iron, b b, 
 c c, which can be taken out at 
 pleasure ; d is a deep flue bringing 
 in air from the outside, and having 
 two openings into the kiln, covered 
 with fire-bars, upon each of which 
 a coke fire, e, is maintained. A 
 sheet of corrugated iron, /, is hung 
 up over each fire, in order to pre- 
 vent the clay immediately above 
 it from being too strongly heated. 
 Both the upper and lower floors 
 of the kiln can be entered by large 
 doors. The charging is all done 
 from the floor a; a few of the 
 
 plates are taken up on each side, I~o : s~o 1 2. 3 4. a 
 
 the sheets b b removed, and clay 
 
 is wheeled in barrows along a and tipped on to c. The plates b 
 are replaced and similarly covered with a charge of clay, and 
 finally a receives a layer of damp clay 6 or 8 inches thick. The 
 doors are shut and the fires lighted ; though the heat is con- 
 siderable, it is not enough to prevent men going in from time to 
 time to put on more fuel, if required. The moisture-laden air 
 ascends and escapes through the roof at g. 
 
 Kroiris Stove. Krom's stove has a series of inclined shelves, 
 something like those of the Hasenclever furnace, down which the 
 mineral gradually makes its way under the action of gravity, 
 while exposed to the direct action of the hot gases coming from 
 a fire.* 
 
 RiebecKs Stove. Riebeck's "Tellerofen" consists, as its Ger- 
 man name denotes, of a number of superposed circular plate- 
 like shelves; a central revolving shaft carries arms with 
 
 * Sahlin, "Magnetic Separation of Iron Ore," Eng. Min. Jour., vol. liii. 
 1892, p. 638. 
 
 SCALE OF FEET 
 5 5 10 
 
 SCALE OF METRES 
 
59$ 
 
 ORE AND STONE-MINING. 
 
 (-JD 
 
 teeth or knives which alternately 
 cause the mineral to travel out- 
 wards and inwards. Thus the 
 mineral fed on to the top shelf, 
 for instance, will be made to 
 travel outwards to the circumfer- 
 ence, where it drops through 
 holes on to shelf No. 2 ; here the 
 revolving teeth, arranged in the 
 reverse fashion, draw it in gradu- 
 ally to the centre, where it falls 
 upon shelf No. 3, and it goes on 
 travelling backwards and for- 
 wards in this fashion until it 
 reaches the bottom of the kiln. 
 During all this time it is sub- 
 jected to the action of the hot 
 gases coming from a fire below. 
 
 Bruntoris Furnace. Though 
 Brunton's calciner (Fig. 692) was 
 invented for the purpose of roast- 
 ing ores, driers have been con- 
 structed upon the same principle; 
 the stove is a circular revolving 
 horizontal bed, with teeth fixed 
 above it which cause the mineral, 
 fed in at the centre, to travel 
 gradually to the circumference. 
 A fireplace on one side sends the 
 products of combustion directly 
 upon the mineral. This stove is 
 used for phosphate of lime, be- 
 sides being employed in the 
 manufacture of patent fuel. 
 
 Ruelle's Stove. Ruelle's re- 
 volving drier (Fig. 678), on the 
 other hand, recalls the Hockin 
 and Oxland calciner. It is made 
 of two long truncated cones of 
 boiler-plate, one inside the other ; 
 the inner one is destined for 
 the drying proper, and the outer 
 one allows the very hot mineral 
 to cool down a little before it 
 is discharged and sent to be 
 ground. 
 
 The outer shell runs upon fric- 
 tion rollers, and both it and the 
 
DRESSING. 597 
 
 inner case have internal projecting spiral blades, which lift the 
 mineral a little and cause it to travel along. At one end there 
 is a fireplace ; at the other a charging hopper and a dust-chamber. 
 The mineral fed by the hopper into the inner cone is gradually 
 brought along by the spiral blades towards the fire-end, whilst it 
 is being exposed to the hot gases of the fire, as well as to a current 
 of hot air blown in by a fan, and heated by its passage through 
 pipes at the side of the fireplace. On reaching the fire-end of 
 the inner cone, the mineral falls through one of four holes into 
 the outer shell, and is now conveyed back by spiral blades to the 
 other end, where it drops into the pit of an elevator, which lifts 
 it high enough for the hopper of the mills. Any dust carried off 
 by the draught is deposited in a chamber built for that purpose. 
 This drier does good work at phosphate mills. 
 
 Rowoldfs Stove. This stove, which is specially designed for 
 brown coal, is made up of a number of small lattice-like shelves 
 down which the mineral gradually drops, while surrounded by 
 air warmed to 75 C. (167^.) by its passage through small pipes 
 heated by steam. 
 
 Steam Stove. The steam stove, also designed for brown coal, is 
 somewhat like the ordinary " Tellerofen." A number of circular 
 drying plates are superposed one above the other in a cylindrical 
 casing, and are heated by steam passing under them. 
 
 Schulzs Stove. Schulz's steam stove is a large revolving iron 
 cylinder like a tubular boiler, 19 feet to 20 feet long, and 7 
 to 8 feet in diameter, traversed by 180 or 200 small pipes 4 inches 
 in diameter and a large central one. The cylinder is inclined to 
 the horizon at an angle of 5 to 6. The exhaust steam from an 
 engine is passed into the large central tube and finds its way 
 through holes into the space outside it, heating the small tubes 
 and their contents. The mineral is carefully fed from a hopper 
 into the small tubes at the upper end, so as to prevent any choking, 
 for otherwise the free passage of the air would be impeded, and 
 the drying would be very imperfect. 
 
 Jacobi's Stove. In the Jacobi stove the mineral falls down 
 over a series of pentagonal cast-iron pi pes heated by the passage 
 of steam, instead of the plain lattice-like shelves of the Rowoldt 
 apparatus, in addition to being exposed to an atmosphere of hot 
 air. 
 
 Many of the brown-coal driers are specially designed so that 
 the products of combustion of the fire do not come into contact 
 with the mineral, for fear the charge might be ignited accidentally. 
 This difficulty does not crop up with many of the other minerals 
 which have to be dried, though it is important with some that 
 the degree of heat to which they are exposed should not be too 
 great. 
 
 (4) LIQUEFACTION AND DISTILLATION. The 
 miner resorts to melting as a purifying or preparatory process in 
 
598 OHE AND STONE-MINING. 
 
 treating amber, antimony ore, asphalt, ozokerite, and sulphur ; 
 and in the very exceptional case of carbonic acid, a gas is coin 
 pr essed to the liquid state. 
 
 Small lumps of amber, after having had the dark outer rind 
 dissolved away, are melted together before being sold to the 
 varnish merchants.* 
 
 The liquation of antimony ore is usually regarded as a metal- 
 lurgical process ; but if a mere melting is carried on at the mine 
 in order to rid an ore of earthy matters, there is no more reason 
 for refusing this operation a place among " dressing " processes, 
 than there would be for excluding the similar purification of 
 asphalt, ozokerite, or sulphur. This is an instance of the difficulty 
 of defining the boundaries between the province of the miner and 
 that of the smelter. The domain of the former is already so 
 large that it does not require to be extended unnecessarily, and 
 as the liquation of antimony ore is fully described in many 
 metallurgical text-books the process may be dismissed here in a 
 very few words. It is based upon the easy fusibility of stibnite. 
 The impure ore coming from the mine is subjected to the action 
 of heat in pots or tubes ; the stibnite melts, trickles away from 
 the earthy matters with which it is mixed, runs into moulds and 
 is allowed to cool gradually, furnishing the crude antimony of 
 commerce. 
 
 Trinidad pitch is purified or refined in the island by being 
 melted in iron pans ; much of the intermingled earthy matter 
 sinks, and the supernatant comparatively pure product is ladled 
 out into moulds. 
 
 The asphalt rock of Seyssel t is prepared for the market by 
 melting it up with Trinidad pitch, or pitch obtained from bitu- 
 minous sandstone, in the proportion of i of pitch to 14 of the 
 finely crushed rock. When the mixture has become pasty, it is 
 cast into blocks weighing about J cwt. each. Tuese are now- 
 ready for sale for making pavements. 
 
 The sponge-like masses of gold obtained by the distillation 
 of amalgam are melted in crucibles and cast into ingots for 
 sale. 
 
 The comparatively clean pieces of ozokerite, which have been 
 picked out, below and above ground, and scraped clean, are 
 more fully purified by melting ; the heavy refuse sinks to the 
 bottom, whilst the pure wax is decanted off and poured into 
 cylindrical moulds. 
 
 By far the greater portion of the native sulphur of Sicily is 
 extracted from the limestone, or other rock by which it is accom- 
 panied, by a simple process of liquation in kilns ; the necessary 
 heat is produced by the combustion of part of the sulphur in 
 the rock, it being cheaper in Sicily to do this than to import 
 
 * n. u. h. Z., 1887, p. 24. 
 
 t Malo, UAsphalle, Paris, 1888, p. 52. 
 
DRESSING. 
 
 599 
 
 fuel. The "calcarone," * or large kiln (Figs. 679 and 680), as 
 distinguished from the " calcarella " or small one, is a circular 
 pit surrounded by a wall, having a sloping bed leading to a 
 rectangular aperture in front. The bed is covered with a layer 
 of burnt refuse (ginese) from a previous operation, which is 
 stamped down hard. The charging proper then begins, the 
 large lumps are placed on the bottom, and various small 
 vertical chimneys are left as passages for the air; when the 
 " calcarone " is full up to the level b e, the mineral is heaped up so 
 as to form a conical pile b c d e, which is covered over with a 
 
 FIG. 679. 
 
 PLAN 
 
 layer of fine " ginese." The thickness of the outer covering of 
 refuse varies according to the season. The total charge of a 
 large "calcarone" may be as much as 700 tons. The aperture f 
 in front is closed with a thin wall, built with plaster of Paris, and 
 the charge is lit at the little chimneys. The heat produced by 
 the combustion of part of the sulphur liquefies the remainder, 
 which gradually runs down the bed to the front wall, and is either 
 tapped from time to time or is allowed to escape continuously 
 into moulds. Some of the large " calcaroni " take three months 
 before they are burnt out completely. 
 
 It is reckoned that one-third or even two-fifths of the sulphur 
 
 * Parodi, SuWestrazione dello solfo in Sicilia, Florence, 1873, P- 49 ^^ e 
 word " calcherone " is also used. 
 
6oo OEE AND STONE-MINING. 
 
 in the rock are consumed in liquefying the part that is 
 obtained. This immense loss of such a valuable material has 
 very naturally caused inventors to turn their attention to cheaper 
 methods of extraction; but even as late as the year 1889, 
 nearly seven-eighths of the total quantity of sulphur obtained in 
 Sicily were extracted by the " calcarone " process. A little was got 
 by a steam extractor and about 10 per cent, of the total pro- 
 duction by Gill's regenerative furnace;* the former is an iron 
 vessel into which steam is conducted after it has been filled with 
 mineral ; the sulphur melts under the action of heat and runs 
 out at the bottom. 
 
 Rich sulphur rock is sometimes subjected to distillation in 
 iron retorts in order to extract the valuable element with less 
 loss than that of the kilns, and the process is also employed in 
 expelling mercury from amalgam. 
 
 In order to produce a commercial article suitable for despatch 
 to a distance, the natural carbonic acid of Germany is compressed 
 into the liquid state. The gas coming from the bore-hole is led to a 
 double pump. The first pump compresses the gas to a certain 
 extent, and forces it through a worm in a cooling tank ; a second 
 pump then takes up the process, and compressing the gas still 
 further sends it through a second cooling worm into strong 
 bottles, made of wrought-iron or steel, in which the actual lique- 
 faction takes place at a pressure of 31 atmospheres. 
 
 The bottles are of four sizes, for holding 4, 8, -10, or 20 kilos, 
 of liquid acid. An 8-kilo. bottle weighs 37 kilos, when empty, 
 or 45 when full ; the dead weight which has to be transported is 
 therefore very great. 
 
 (5) MAGNETIC ATTRACTION. Magnetism is applied 
 in dressing either for treating poor iron ores, in order to produce 
 a concentrate richer in metal and freer from noxious elements 
 than the crude material, or for extracting magnetic particles from 
 ores of bismuth, copper, gold, lead, or zinc, in which iron minerals 
 play the part of troublesome refuse. 
 
 The machines for treating ores magnetically may be classified 
 as follows : 
 
 Kiud of Machine. Name of Inventor or Machine. Mode of Working. 
 
 Endless belt 
 
 Rolls 
 
 Deflection 
 
 * JSioista del servizio minerario nd 1889, Florence, 1890, p. 83. 
 
 a. Chase 
 
 Wet or dry. 
 
 b. Conkling 
 
 Wet. 
 
 c. Edison 
 
 Dry. 
 
 d. Hoffman 
 
 }j 
 
 e. Kessler 
 
 
 /. Lovett-Finney 
 
 Weft. 
 
 g. Ball-Norton (" Monarch ") 
 
 Dry. 
 
 h. Buchanan 
 
 
 i. Friederichssegen 
 
 }> 
 
 j. King 
 
 tt 
 
 k. Wenstrom 
 
 
 /. Edison 
 
 Jt 
 
DRESSING. 60 1 
 
 Endless Belts. (a) The Chase sepaiator* (Fig. 681) has two 
 endless belts with magnets underneath. A, B are two revolving 
 iron rollers 4 inches in diameter and 3 feet long, converted 
 into magnets by electric currents, and the space between them is 
 occupied by a stationary electro-magnet ; C is a driving pulley, 
 and D a tightening pulley. A cotton belt is made to travel 
 round these four pulleys in the direction shown by the arrow. 
 F is another magnetic roller, and G a driving pulley for the 
 second belt, travelling as shown. 
 
 The ore is fed on to the belt at the point E, and on arriving at 
 A the non-magnetic waste is thrown off by centrifugal force, whilst 
 the magnetic particles are attracted and held against the belt. All 
 the time they are passing from A to B they are subject to the in- 
 fluence of the electro-magnet, and owing to its construction they 
 come under the influence of a succession of poles alternating in 
 polarity. Tiiis causes the particles to turn over constantly and 
 so free themselves from the non-magnetic or slightly magnetic 
 
 FIG. 68 1. 
 
 
 grains, which fall into the compartment immediately below the 
 belt, destined for the middlings. The thoroughly magnetic par- 
 ticles travel with the belt to B, and as it moves up and the 
 influence of B becomes less sensible, they are attracted by the 
 third magnetic roller F, and at last leaping across the small inter- 
 vening space, they are carried up the belt to G, where they drop 
 off into the box containing the ** heads." In making the little 
 jump from B to F they still further free themselves from incom- 
 pletely magnetic middlings. 
 
 (6) The Conkling machine (Fig. 682) is an inclined endless 
 belt travelling upon a roller at each end, with stationary electro- 
 magnets E E under the upper half. The ore is fed on from a 
 hopper, and is subjected to the action of a stream of water ; 
 this washes down the non-magnetic particles, whilst the magnetite 
 adhering to the belt is carried over the top end. The Conkling 
 machine may therefore be looked upon as a Brunton separator 
 
 * Sahlin, "Magnetic Separation of Iron Ore," Eng. Min. Jour., vol. liii., 
 1892, p. 663. This article gives recent information on ihe subject of 
 magnetic separation, and has furnished not only the account of the Chase 
 machine, but also many of the details concerning some of the others. See 
 also Tram. Amer. Inst. M.E., vol. xvii., 1890, p, 728. 
 
602 ORE AND STONE-MINING. 
 
 in which the rich grains are held against the belt by magnetic 
 attraction, and thus enabled to resist the force of the stream of 
 water. 
 
 (c) Edison's second separator, which is used for the final 
 treatment of re-crushed concentrates, furnished by the deflection 
 machine (p. 606), is an endless belt placed vertically, with electro- 
 magnets behind one side; they attract the fine particles of magnetite 
 and cause them to adhere sufficiently to be carried upwards, whilst 
 the non-magnetic grains drop. The electro-magnets are arranged 
 so that the particles travel over magnets alternating in opposite 
 polarity; this causes, as in the Chase machine, a succession of 
 tumbles or somersaults, which set free the non-magnetic particles 
 and allow them to fall. The magnetite is carried up over the top 
 roller by buckets attached to one side of the belt. 
 
 (d) The Hoffman separator * ( Fig. 683) is an endless belt arranged 
 
 horizontally upon the two 
 
 FIG. 683. drums A and B, provided with 
 
 two sets of magnets. The 
 magnets C and also those 
 inside the drum B have their 
 poles arranged alternately. 
 When the ore is fed on to the 
 belt from the hopper, it travels 
 along over the magnets C, and 
 is subject to magnetic attrac- 
 tion varying in amount, ac- 
 cording to the distance from 
 
 the pole, and also in polarity. This action tends to make the 
 magnetic particles group themselves into a layer resting imme- 
 diately upon the belt, whilst the non-magnetic particles lie upon 
 the top. On arriving at B these latter are easily thrown off Vy 
 centrifugal force, and fall into the compartment E, whilst the 
 magnetic grains still cling to the belt. Those which are in- 
 completely magnetic drop at F ; a better product is collected at 
 G, and a clean concentrate at II. The partitions, which separate 
 the waste and divide the orey shower into classes of varying rich- 
 ness, can be set so as to obtain any kind of classification which is 
 most suitable to the ore under treatment. 
 
 A blast of air is drawn along the face of the belt in the opposite 
 direction to that of its travel, and helps to set free any non- 
 magnetic grains caught up between the others. 
 
 (e) Kessler,f of Oberlahnstein, is the inventor of a machine 
 acting in a totally different manner (Fig. 684). It is a broad, 
 endless belt or chain, armed with a number of iron points, travel- 
 ling over the two rollers A and B ; the former is an electro- 
 
 * "The Hoffman Magnetic Separator," Eny. Min. Jour., vol. Hi., 1891, 
 p. 680, 
 
 f D. u. h. Z., 1891, p. 382. 
 
DRESSING, 
 
 603 
 
 magnet, the latter is made of wood. The stuff* falls from the 
 hopper F into the conveyor 0, which feeds it across the whole 
 width of the cylinder A, and then drops into the curved gutter G, 
 where the iron points are drawn through it as the belt revolves. 
 The points, while under the influence of the electro-magnet A, 
 pick up the magnetic particles, and let them drop into the 
 compartment E on losing their power, while the non-magnetic 
 particles fall at D. The partition between can be placed 
 
 FIG. 684. 
 
 FIG. 685. 
 
 FIG. 686. 
 
 in any suitable position. This machine has been used in Spain 
 for separating iron ore from calamine, after the former has been 
 made magnetic by a reducing calcination. 
 
 (/) Lovett-Finney machine (Fig. 685 ) in some respects resembles 
 the Conkling separator. It is a wet machine, consisting of an end- 
 less canvas belt travelling upon two drums, A and B, one of which, 
 A, has its outer surface made of bars of iron ; these become magnets 
 of alternate polarity, as they are connected alternately with the 
 iron di^cs forming the ends of the drum, which form the poles of 
 an electro-magnet. The ore is fed against the belt about half-way 
 up the magnetic drum A, and as the belt revolves with the drum, 
 the magnetic particles are carried up, whilst the non-adherent 
 waste is washed off by a stream 
 of water. The concentrate is 
 conveyed over the pulley B into 
 a tank, and drops off, as it is no 
 longer subject to the attractive 
 force. 
 
 (g) Rolls. In the Ball-Norton 
 machine (Fig. 686) the magnetic 
 particles are drawn against re- 
 volving drums made of paper pulp, 
 instead of being attracted to the surface of a canvas belt. There are 
 two drums, A and B, revolving in the same direction, in each of which 
 are arranged electro-magnets capable of holding magnetic particles 
 against a certain portion of the under surface. As usual, the magnets 
 are alternate in polarity. The ore is fed from a hopper C against 
 the roll A, tho tails drop at once into D, and the adherent 
 magnetite travels along with the roll till it begins to Iqave the 
 
604 
 
 ORE AND STONE-MINING. 
 
 FIG. 687. 
 
 magnetic field; the centrifugal force now overpowers t^e 
 magnetic attraction, throwing the grains against the roll B. 
 Those which are completely magnetic attach themselves to B, while 
 ore mixed with waste falls into the compartment E ; lastly, the 
 clean magnetite, on escaping from the influence of the magnets, 
 yields once more to the centrifugal force and is deposited at F. 
 A strong current of air is being constantly drawn through the 
 machine in the opposite direction to the travel of the ore and 
 assists in the cleaning. 
 
 (A) The Buchanan separator* (Fig. 687) is made of two cast- 
 iron rolls, revolving in opposite directions, supported on the ends 
 of an electro-magnet ; the two rolls thus 
 become the poles of a huge horse-shoe 
 magnet, and the magnetism is most 
 strongly developed where they most 
 closely approach each other. As the ore 
 drops down between the rolls, the mag- 
 netic particles fly to them, and are 
 carried along until they fall off at the 
 M sides, when the centrifugal force over- 
 powers the now diminishing magnetic 
 attraction, The poor non-magnetic par- 
 ticles fall vertically. 
 
 (i) Zinc blende found mixed with 
 chalybite at Friederichssegen is roasted, 
 so as to convert the latter mineral into 
 magnetite, and then treated in the machine shown in Figures 688 
 and 689. It is composed of a brass cylinder A, with a number of 
 little ridges S, parallel to the axis, and four sets of stationary 
 electro-magnets B. T is the ore-hopper which supplies the feeder 
 D : this is a sheet-iron tray, which is made to oscillate by cams 
 upon a little shaft driven by the pulley Q. P is the main belt 
 pulley upon H, the shaft of the brass drum, and E, is a pulley 
 which drives Q by a belt.f 
 
 A regular stream of fine ore is fed against the brass cylinder by 
 the feeder D, and the grains of blende at once fall into the com- 
 partment Z ; the magnetic oxide of iron is held against the 
 cylinder by the attraction of the electro-magnets, and is carried 
 over by the little longitudinal ridges until it falls into the com- 
 partment F. 
 
 ( /) King's J magnetic dre.-.sing machine works by the aid of 
 permanent magnets fixed upon a revolving drum. Like other 
 inventors he arranges his magnets so that their poles alternate, 
 
 * Enq. Min. Jour., vol. xxxv., 1833, p. 133 ; vol. xlvii., 1889, p. 542. 
 
 t Bellom, " Etat actuel de la preparation mecanique dans la Saxe, le 
 Hartz et la Prusse Khenane," Annales des Mines, ser. 8, vol. xx., 1891, p. 5 ; 
 J>. u. h. Z., 1892, p. 37. 
 
 Fifty-third Ann. Rep. R. Corn. Pol Soc. Falmouth, 1885, p. 44, 
 
DRESSING. 
 
 605 
 
 and he thus makes the grains tumble over and shake off any 
 loosely intermingled non-magnetic particles. 
 
 (&) The Wenstrom * is a Swedish machine, which has been in use 
 at Dannemora and other mines for some years (Fig. 690). It has a 
 stationary electro-magnet A, and a revolving armature barrel B, 
 consisting of a number of soft iron bars separated by strips of 
 
 FIG. 688. 
 
 FIG. 689. 
 
 -i 3> 
 
 wood. The electro-magnet lies on one side of the centre of the 
 barrel, so that the iron bars of the armature become magnetised 
 only during part of the revolution. C is a tray feeding the ore 
 on to the top of the barrel, D a shoot for the non-magnetic 
 particles, and E the shoot for the concentrate. The magnetic 
 grains adhere to the soft iron bars when these are close to the 
 electro-magnet, and are carried past D as the barrel revolves; 
 
 E, M. J., vol. xlvi., 1888, p. 437. B. u. h. Z., 1891, p. 178. 
 
606 ORE AND STONE-MINING. 
 
 as the bars recede from the electro-magnet, they lose their power 
 and let the iron ore drop into E. 
 
 (1) Deflection. The simplest of all magnetic separators is one 
 devised by Edison (Fig. 691).* It is based upon the fact that if a 
 thin sheet of finely crushed ore drops past a powerful electro- 
 magnet, the magnetic particles will be drawn towards it and 
 deflected from their direct downward path, whereas the non- 
 magnetic particles will fall vertically. If a partition is fixed in a 
 suitable manner, the concentrate falls on one side and the waste 
 on the other. Diagrammatically the machine may be shown 
 thus : A A represent the electro-magnets, B a hopper delivering 
 the fine ore through a long narrow slit; is a thin partition. 
 The waste falls vertically into the compartment D, and the iron 
 ore into E. 
 
 Magnetic separators are chiefly used for concentrating the 
 
 FIG. 690. FIG. 691. 
 
 magnetite from ores that are too poor to go to the furnace in the 
 crude state ; and it has been proposed to make brown hematite 
 magnetic by partial reduction at a low red-heat, but other uses 
 have been mentioned in describing the various machines. For 
 instance, by the ordinary washing processes it is impossible to 
 separate chalybite with a density 37 to 3*9 from blende with a 
 density of 3-9 to 4-2. The aid of magnetism is here invoked with 
 success as already explained. 
 
 The Namaqua Copper Company use King's magnetic separator 
 for extracting the magnetite which is mixed with bornite and 
 chalcopyrite, in order to obtain a product richer in copper. 
 
 In a similar manner a magnetic concentrator of the Ball-Norton 
 type has been employed in Queensland for treating a mixed con- 
 centrate of magnetite and bismuth ore, obtained by a wet-dressing 
 process. The percentage of bismuth is raised in this way from i o 
 or 12 to 20 per cent. 
 
 On a small scale, the magnet is of service for extracting magnetic 
 
 * E. M. /., vol. lix. 1889, p. 479, and vol. liii. 1892, p. 662. 
 
DRESSING. 607 
 
 particles when washing samples of tin ore on the vanning shovel, 
 or gold in the batea. 
 
 (6) FRIABILITY. Some minerals are more easily crumbled 
 and reduced to powder than others, and if the difference in 
 friability is great, it is possible after crushing to effect a separation 
 by a mere process of sifting. An instance of this rare method of 
 concentration occurs at the graphite mines near Pasau, in 
 Bavaria.* The softer kinds of mineral obtained from the mine are 
 ground in mills, when the thin greasy elastic plates of graphite 
 arrange themselves parallelly to the surface of the stones, and 
 preserve their flat shape, while pieces of more brittle minerals are 
 reduced to the state of fine powder. The ground product is sifted 
 upon fine silk cloth, the dust poor in graphite passes through the 
 fine holes, but the scales of graphite are left behind. As might 
 be supposed, the separation is not very thorough. 
 
 Biittgenbachf has separated blende from iron pyrites in a 
 somewhat similar way, the former mineral being much more easily 
 pulverised than the latter. He used a Vapart disintegrator to 
 treat a mixture of blende and pyrites, in grains ^ inch to inch 
 across, and by suitably regulating the speed, he was able to reduce 
 the blende to the state of fine sand without affecting the pyrites 
 to any appreciable extent. The blende extracted by sifting con- 
 tained 50 to 55 per cent, of zinc, whilst the pyrites was almost free 
 from this metal. 
 
 The dressing of the plumbiferous sandstone of Mechernich is 
 probably the most important instance of a difference in friability 
 affecting the method of treatment. The little concretions of 
 galena and quartz are comparatively hard and the sandstone very 
 friable. The greater part of the stuff coming from the mine has 
 crumbled to the state of loose sand before it reaches the works, 
 so that the first comminution, which sets free the rich knots, is 
 sufficiently effected by the mere handling, without the powerful 
 crushing machinery usually required for the preliminary treatment 
 of a lead ore. 
 
 III. PROCESSES DEPENDING UPON CHEMICAL 
 PROPERTIES. 
 
 (i) SOLUTION, EVAPORATION, AND CRYSTALLI- 
 SATION. Processes of this kind are employed by the miner in 
 some of the few cases where the mineral is soluble in water ; aid 
 is derived from certain other solvents, such as benzine and hydro- 
 chloric acid. 
 
 The principal minerals soluble in water are borax, nitrate of 
 soda, potassium salts, and common salt. 
 
 * Andree, " Der osterreichische und bayerische Graphitberghan," 
 B. u. h. Z., 1890, p. 270. 
 
 t " Aufbereitung von Blende und Schwefelkies," /?. u. h. Z. } 1881, 
 p. 294. 
 
608 ORE AND STONE-MINING. 
 
 The crude borax of California* is ground and thrown into 
 a pan containing a boiling saline solution, frequently the mother- 
 liquor from the second crystallisation. The salts dissolve and the 
 sand sinks to the bottom. The hot solution is allowed to stand so 
 as to clarify, and is then run off into pans and left to cool for five 
 to nine days, during which time the borax crystallises out. The 
 crystals obtained in this way are somewhat impure. They are 
 refined by being dissolved and allowed to crystallise a second time. 
 
 Nitrate of soda is treated on a larger scale. f The caliche, 
 crushed into lumps about 2 inches across, is tipped into large 
 
 btangular boiling tanks full of water, which are heated by a 
 
 iral 3-inch steel pipe with steam at a pressure of 60 Ibs. to 
 
 je square inch. The boiling is carried on by Shanks' lixiviating 
 
 [stem, which causes a continual circulation of the lighter liquid 
 \ the other boiling tanks by following the denser and heavier 
 plution. As soon as the solution is concentrated to no by 
 Nvaddell's hydrometer, it is allowed to settle for a short time, 
 .nd is then drawn off to the crystallising tanks. The refuse in 
 [he boiling tanks is again treated with water in order to extract a 
 Jittle nitrate which it still contains. 
 
 The crystals are shovelled out on to drying floors and put up 
 in sacks for export. 
 
 The mother-liquor, which contains a little sodium iodate, is 
 added to the water used for dissolving a fresh stock of " caliche," 
 and by repetitions of the process it becomes rich enough for the 
 extraction of the iodine ; this is precipitated by sodium bisulphite, 
 washed and pressed into cakes. The crude iodine so obtained is 
 purified by sublimation. 
 
 The principal potassium salt of Stassf urt is carnallite, a hydrated 
 double chloride of potassium and magnesium. Some of it is treated 
 on the spot in order to produce commercial chloride of potassium. 
 
 The crude mineral, after being coarsely ground, is treated with 
 hot water, and the strength of the solution is so arranged that only 
 the chlorides of potassium and magnesium are dissolved out. The 
 residues are treated with cold water which dissolves out some 
 sodium chloride and leaves behind kieserite (hydrated magnesium 
 sulphate). This is passed through a fine sieve, moulded into 
 blocks, and sold. 
 
 The solution of the chlorides of potassium and magnesium is 
 allowed to settle and cool, and three products are obtained from 
 it : (a) crystals of potassium chloride ; (b) mother-liquor ; (c) slimes. 
 
 The crystals (a) still contain a little sodium chloride. They are 
 lowered into water in iron vessels and much of the sodium chloride 
 
 * C. Napier Hake, " An Account of a Borax Lake in California," Jour. 
 Soc. Chem. Ind., vol. viii., 1889, p. 854. 
 
 t Harvey, " Machinery for the Manufacture of Nitrate of Soda at the 
 Ramirez Factory, Northern Chili,'' Proc. Inst. C. E., vol. Ixxxii., 1884-85, 
 P- 337- 
 
DRESSING. 609 
 
 is dissolved out ; they now contain 80 per cent, of potassium chloride, 
 and after being freed from moisture in Thelen's drier, they are 
 packed in bags and sold. 
 
 The mother-liquor (b) is heated and gives crystals of artificial 
 carnallite, which are treated again in the same way as the native 
 mineral. On evaporation the final mother-liquor yields hydrated 
 magnesium chloride. 
 
 The slimes (c) are put into a filter press, and the solid cakes 
 so obtained are calcined and sold as marmie after being ground. 
 They owe their fertilising value to some potassium chloride which 
 they still contain. 
 
 The evaporation of brine may be carried out naturally or 
 artificially. In Southern Europe, and in other countries where 
 the sun has sufficient power, sea water led into shallow ponds 
 gradually becomes concentrated enough to deposit salt. In 
 Germany, weak brine is strengthened by allowing it to trickle 
 down through brush-wood contained in huge frameworks of 
 timber. A great surface is thus exposed to the atmosphere with 
 much evaporative effect if the weather is dry. 
 
 In this country common salt is mostly obtained from brine 
 pumped up out of bore-holes or out of inundated salt mines. 
 After being allowed to settle, the brine is evaporated in large 
 sheet-iron pans heated by the flame of a coal fire passing under- 
 neath along flues. Some of the pans in the Middlesbrough district 
 are 70 feet long and 24 feet wide, with a depth of 20 inches at 
 the fire-end, and gradually lessening to 16 inches at the other. 
 In Cheshire, even larger pans may be seen, some, in fact, as much 
 as 100 feet long by 45 feet wide. The heat of the fire gradually 
 drives off the water, and crusts of salt form on the surface; they 
 fall to the bottom and are shovelled out ; after beirg allowed to 
 drain, the salt is ready for despatch to the alkali works. 
 
 At Bex, in Switzerland, where fuel is dear and water-power 
 abundant, the brine is evaporated in a closed boiler, like a large 
 egg-ended steam boiler, heated from below; the process of 
 evaporation goes on continuously, brine being constantly pumped 
 in and salt being drawn off as it is deposited. 
 
 Benzine is employed in the exceptional case of ozokerite for dis- 
 solving out remnants of the mineral left in some of the residues. 
 
 Heavy spar stained by oxide of iron is " bleached " by sulphuric 
 acid ; the mineral, after being crushed to the state of coarse 
 powder, is put into lead-lined vats with dilute sulphuric acid, 
 which is brought to the boiling-point by the injection of steam. 
 The acid dissolves the oxide and leaves white bary tes ready for 
 grinding after it has been dried. 
 
 Tin ore contaminated with copper ore may be freed from the 
 latter metal by hydrochloric acid ; the so-called " burnt leavings," 
 that is to say the tailings produced in washing the roasted 
 concentrates of tin ore, originally enveloped or accompanied by 
 
 2 Q 
 
6 ro ORE AND STONE-MINING. 
 
 sulphides, are treated with hydrochloric acid ; the coppery solution 
 is led into pits, where the metal is precipitated by iron. 
 
 (2) ATMOSPHERIC WEATHERING. I must point out 
 that though weathering often results from mere loss of water, 
 it may in other cases be caused by the chemical decomposition of 
 one of the minerals contained in the stuff under treatment. As 
 already stated, the boundaries between the various dressing pro- 
 cesses are not distinctly denned. 
 
 The crumbling-up of the diamond-bearing rock under atmospheric 
 agencies plays an important part in the extraction of the gems, 
 and with no other mineral is a weathering action of this kind 
 carried out on so large a scale or in such a systematic manner. 
 The floors devoted to this process at De Beers* mine occupy 
 some thousands of acres. They are merely fairly level ground 
 from which the bush and grass have been removed, and which 
 has been rolled to make it hard. The ground is laid out in 
 rectangular sections, 600 yards long and 200 wide, and is enclosed 
 by high wire fences. Main lines of rails on each side of the 
 floors and subsidiary portable lines serve to bring the trucks of 
 " blue," which is tipped and spread out so that a load, i.e., 16 
 cubic feet or 1600 Ibs., will occupy an area of 21 square feet. 
 
 After being left for some time, the " blue " is broken up by 
 means of picks into pieces not larger than 4 inches cube, and 
 is again left to dry for a further period, until most of the natural 
 water has evaporated. The artificial " diamond field " is then 
 watered, to aid the disintegration, and lastly harrowed and rolled ; 
 in fact, the miner endeavours to bring about the pulverisation 
 somewhat in the same way that the farmer prepares his land for 
 tillage. 
 
 The stuff is known at first as " coarse blue ground," then as 
 " broken blue ground," and finally, after the rolling, as " pulverised 
 blue ground." 
 
 The length of time required for this disintegration depends not 
 only upon the atmospheric conditions that is to say, the season 
 of the year and the amount of rain but also upon the mine 
 from which the blue is obtained. The blue from Kimberley 
 mine becomes sufficiently disintegrated in three months in 
 summer, whilst the De Beers blue requires double that time. It 
 is evident, therefore, that a very large stock of blue has to be 
 kept on the floors, if the washing machines are to be supplied 
 regularly. 
 
 The diamond is not the only gem which may be released from 
 its matrix by disintegration under atmospheric agencies. The 
 garnetiferous gravel of Bohemia t was at one time allowed 
 
 * Pe Beers Consolidated Mines, Limited, Second Annual Iteport for the 
 Year ended ^ist March, 1890, p. 1 8. 
 
 f Raymond, Di-cussion upon Kunz's paper on " Bohemian Garnets," 
 Irans. Arr.er. Inst. M. E., vol. xxi., 1892, p. 249. 
 
DRESSING. 61 1 
 
 to weather for three months on the surface, in order to fit it for 
 the subsequent washing process. 
 
 Phosphate of lime occurring in the form of nodules in clay is 
 treated in a like manner. The phosphate dug from open pits in 
 the Lias in the department of the Haute-Saone * is left exposed 
 to the air often all the winter ; a part of the earthy matter falls 
 off, and the nodules have simply to be screened dry, in order to 
 separate a large portion of the clay with which they were 
 only originally mixed. Again, in the Yosges there is a phos- 
 phatic bed of the same geological age, consisting of soft nodules 
 forming only ~Q or J of the bed of brown clay by which they 
 are enveloped. The stuff is spread out on the fields and raked 
 over occasionally. The clay crumbles off, and at the same time 
 the nodules harden from losing their moisture ; they are then 
 picked out by hand. 
 
 Nodules of clay ironstone are freed from shale in a similar 
 way ; and ores of iron more or less contaminated with iron or 
 copper pyrites gradually have a portion of their sulphur washed 
 out in the form of soluble sulphates, if exposed for a sufficient 
 time to the action of air and rain. 
 
 Fire-clay is found to be better suited for making bricks after 
 weathering for some months, than when first raised from under- 
 ground. 
 
 (3) CALCINATION OR BOASTING. The object of 
 calcination or roasting may be : 
 
 a. To effect a change in the chemical composition of a valuable 
 mineral, and so produce either an ordinary article of commerce or 
 one that is more readily saleable than the raw material. 
 
 6. To effect a change in the chemical composition of some of 
 the substances accompanying a valuable mineral, and so get rid 
 of them partially or render them more easily separable by other 
 processes. 
 
 The commonest example which can be cited is burning 
 limestone ; the action of heat is made use of to drive off 
 the carbonic acid and leave quicklime. Another instance is 
 furnished by clay ironstone, or any ore in which the iron occurs 
 mainly in the form of carbonate. Simple exposure to heat con- 
 verts ferrous carbonate into magnetic oxide ; the former contains 
 48 per cent, of iron, the latter 72 per cent. ; consequently, if the 
 ore has to be sent to a distance there is a saving in freight, 
 besides which the ore is more acceptable to the ironmaster for his 
 furnaces. 
 
 Gypsum is calcined in order to expel the water chemically 
 combined with it, and convert it into plaster of Paris. 
 
 With the ores of arsenic, it is the valuable ingredient which is 
 driven off. Mispickel and other arsenical ores are roasted at 
 
 * titatistique del'industrie mintrale en France et en Alytrie en 1886, Paris, 
 1888, p. 268 and p. 282. 
 
612 ORE AND STONE-MINING. 
 
 mines in order to produce arsenious acid, which is collected in 
 special flues. 
 
 Ores of copper are sometimes calcined at mines, with the 
 object of extracting the arsenic before sale to the smelters, who 
 would pay nothing for this latter metal and prefer its absence. 
 
 Calcination is resorted to in the case of some iron ores in order 
 to get rid of the sulphur, due to intermixed iron pyrites or pyrrho- 
 tine, and so free the ore from an element which the smelter dislikes. 
 Thus in Northamptonshire the undecomposed greenish lumps in 
 the bed are picked out on account of the sulphur they contain, 
 and put aside. When a sufficient quantity has accumulated, a 
 heap is made with a little coal and fired ; the ore loses nearly all 
 its sulphur in the burning and is thus fitted for the blast- 
 furnace. 
 
 Auriferous ores are roasted in some instances for the purpose 
 of liberating the gold which is so enveloped in sulphides and 
 sulpharsenides, such as iron pyrites and mispickel, as to be caught 
 with difficulty by mercury. 
 
 Partially concentrated tin ore (whits) is roasted in order to 
 convert iron pyrites and mispickel into pulverulent oxides which 
 can easily be separated by washing. Again, tin ore is occasionally 
 associated with a considerable amount of wolfram, which 
 approaches it so closely in density that separation by washing is 
 impossible. The mixed concentrate obtained by the ordinary 
 dressing processes, consisting of cassiterite mixed with wolfram, 
 is roasted with carbonate or sulphate of soda ; soluble tungstate 
 of soda is produced, which is dissolved out by water, leaving 
 behind the insoluble cassiterite fit for the smelter. 
 
 Lastly, we may take the case of zinc ore. Blake * renders the 
 separation of blende from marcasite commercially possible, by 
 roasting the mixed minerals at a temperature sufficient to convert 
 the latter into oxide, while the former remains unchanged. The 
 difference in specific gravity is then sufficient to allow the ordi- 
 nary washing processes to take effect. Smithsonite mixed with 
 limonite f is roasted with coal in order to reduce the ferric oxide 
 to the state of magnetic oxide, and thus render it separable by a 
 magnetic process. 
 
 It now remains to be seen how calcination is carried out. 
 Minerals may be burnt in heaps, in kilns and in furnaces. 
 
 Clay ironstone is usually burnt in heaps with the addition of a 
 little coal ; but one variety, black band ironstone, contains a 
 sufficient amount of carbonaceous matter to burn of itself. 
 
 The spathose ore underlying the limonite ("rubio") at Bilbao 
 is now being successfully calcined on a very large scale previous 
 to shipment. According to Mr. Windsor Richards, * the raw ore 
 
 * " The Separation of Zinc Blende from Iron Pyrites." Trans, Amer. 
 Inst. M. E., vol. xxii., 1893-4 ; and (t) Payne in the Discussion. 
 
 J " Pres. Address to I. and S. Inst ," Cull. Guard., vol. Ixv., 1893, P- 955 
 
DRESSING. 613 
 
 contains 43 per cent, of iron and 25 per cent, of carbonic acid, 
 whilst the calcined ore gives 58 per cent, of iron and only 2 per 
 cent, of moisture. One of the large kilns gets through 1500 tons 
 of raw ore weekly. 
 
 The commonest example of calcination in kilns is making 
 lime. At large works the time-honoured semi -spheroidal kiln 
 with intermittent action is often supplanted by the Hofmann 
 kiln, in which the processes of charging, burning, and discharging 
 go on continuously. 
 
 Some of the baking ovens used for converting gypsum into 
 plaster of Paris, by the simple expulsion of the water of combi- 
 nation, are cylindrical brick kilns so arranged that the flame 
 nowhere comes in contact with the mineral. The fireplace is in 
 the centre, and the hot gases are drawn down flues into an 
 annular arched passage all round the bottom of the kiln, and 
 then ascend through the charge by means of a number of 
 cast-iron pipes. The kiln is covered by a brick dome over 
 which comes a conical hood or chimney. 
 
 In making Parian cement from gypsum a different oven is 
 employed, in which a central coke fire sends out its hot gases 
 directly on to the charge itself. 
 
 The furnaces used by the miner are usually of the reverberatory 
 type, in which the flame plays into the space containing the 
 charge ; the bed may be stationary or revolving. The two most 
 frequently employed in Cornwall and Devon, for roasting the 
 ores of arsenic, copper and tin, are Brunton's calciner and 
 Hockin and Oxland's calciner. The former (Fig. 692) * has a 
 revolving circular bed about 10 feet in diameter, supported by a 
 vertical shaft, which is made to revolve slowly by any convenient 
 source of power, whilst the flames of two fireplaces at the sides 
 play upon it and produce the requisite amount of heat. Depend- 
 ing from cast-iron frames fixed in the roof of the furnace, are 
 three sets of knives or teeth, inclined in such a manner as to 
 shift the ore gradually from the centre, where it is fed on, 
 towards the circumference, where it is discharged. The action of 
 heat in the presence of atmospheric oxygen converts the sulphur 
 and arsenic into sulphurous and arsenious acids, which escape 
 with the other hot gases, and are led into long condensing flues. 
 These are brick or stone passages high enough for a man to 
 stand upright, with partial partitions so arranged as to make 
 the hot gases take a tortuous path. There are large openings 
 on one side for drawing out the arsenical soot at intervals. 
 During the actual calcination these doors or manholes are closed 
 by sheets of iron carefully luted with clay. 
 
 The Hockin and Oxland calciner is not unlike the Bruckner 
 furnace used in the United States, as it is a revolving cylinder 
 
 * Henderson. Op. cit. 
 
614 
 
 ORE AND STONE-MINTNG. 
 
 lined with fire-brick. Figures 693 and 694* show the construction 
 of such a furnace. A is the cylinder lined with fire-brick, set at a 
 slight inclination and supported on rollers. It is made to revolve at 
 the rate of six to eight revolutions per hour ; B is a screw which 
 
 FIG. 692. 
 
 brings down a regular supply of ore from a hopper. The ore 
 travels along very gradually in the direction of the arrow and 
 finally drops into the chamber C. D is the fireplace opening into 
 the lower end of the cylinder, and E is the beginning of the flues, 
 
 * Ferguson, " On the Appliances used for Dressing Tin and Copper Ores 
 in Cornwall," Proc. Inst. Mech. Eny., 1873, P 128. 
 
DRESSING. 
 
 in which the arsenious acid is condensed and through which the 
 sulphurous acid passes on its way to the chimney. The longi- 
 tudinal ribs of fire-brick, extending two-thirds of the length of 
 the furnace from the lower end, serve to lift up the charge and 
 let it fall, so as to expose new surfaces to the action of the air. 
 One of these calciners used some years ago at Devon Great 
 Consols mine was simply an old boiler tube, 30 feet long by 3 feet 
 6 inches in diameter, lined with 4j-inch fire-brick, so that the 
 clear diameter inside was 2 feet 9 inches. Another was made of 
 an old boiler 5 feet in diameter. The inclination was i in 24. 
 
 FIG. 693. 
 
 SCALE 
 
 20 FEET 
 
 7 METRES 
 
 Some of the calamine at Monteponi, which has been concen- 
 trated by the ordinary wet methods until it contains 20 per cent, 
 of zinc, is still much mixed with oxide of iron and dolomite. Two 
 per cent, of coal are added, and the ore is passed through the 
 rotary furnace, 42 feet (13 m.) long, working continuously like 
 the Hockin and Oxland calciner ; the iron is thus brought to the 
 state of magnetic oxide. On leaving the furnace the ore is 
 moistened with water, which causes the calcined dolomite to fall 
 to powder. It is next treated on screens, and the various cate- 
 gories produced are sent separately to a magnetic concentrator.* 
 
 * Oest. Zeitschr. f. B. u. W. vol. xxxvii., 1889, p. 36; and Eng. JUin. 
 Jour., vol.liv., 1892, p. 77. 
 
616 ORE AND STONE-MINING. 
 
 (4) CEMENTATION. The precipitation of copper by iron 
 may fairly be regarded as coming within the province of the 
 miner, when the solution flows naturally out of an adit level 
 or is pumped up from underground, or when it is obtained 
 artificially as a by-product in tin-dressing. On the other hand, 
 the metallurgist may fa ; rly claim such operations as those 
 conducted on a huge scale at Rio Tinto, where the cupreous 
 solution is mainly produced by leaching the ore which has been 
 burnt in heaps, or a mixture of burnt ore and raw ore. However, 
 as in other cases, the line of demarcation between the two do- 
 mains is an arbitrary one, and on this account it is advisable that 
 the mining student should be well grounded in metallurgy. 
 
 The famous old Parys mine in Anglesey, now shorn of its glory 
 owing to the low price of copper, affords the most important 
 example of cementation cariied on at a mine in this country. 
 Coppery water is pumped out of the mine, and is led into 
 brick-lined pits containing scrap-iron. The iron is raked over 
 from time to time, and eventually the old pots, kettles, shovels, 
 meat-tins, &c., pass into solution, while the copper is precipi- 
 tated. As might be imagined, when one looks at the heterogeneous 
 mixture of articles constituting the scrap-iron thrown into the 
 pits, the precipitate is very impure and contains only some 20 to 
 30 per cent, of metallic copper. 
 
 The iron used is not lost ; the ferruginous solution running 
 away from the precipitating pits is led into large pools, and 
 there exposed to the action of air and rain. The dissolved iron 
 gradually passes to a higher state of oxidation, producing in- 
 soluble ochre, and little by little a deposit of this substance forms 
 upon the bottom of the big ponds. According to the strength of 
 the irony solution supplied, the ponds are run dry and cleared 
 out once in every two or three months. Wind and rain aid the 
 process of oxidation. 
 
 (5) AMALGAMATION. Two metals, gold and silver, are 
 extracted from their ores by amalgamation, that is to say, by 
 processes based upon their affinity for mercury ; and here we are 
 once more on the borderland between mining and metallurgical 
 practice. In the case of silver ores, the processes are often 
 complex and require the precious metal to be brought into the 
 state of chloride before amalgamation is possible ; besides which 
 they are frequently carried on at works which do not belong to the 
 mining company. I therefore consider that the miner would be 
 encroaching upon the territory of his neighbour by interfering in 
 this instance, whilst, on the other hand, with gold the process is 
 generally simple, and the ore goes straight from the shaft or 
 adit to crushing and amalgamating works owned by the same 
 company as the mine. 
 
 The amalgamation of gold takes place by mere contact, either 
 when the particles touch the mercury as they slide or roll along 
 
DRESSING. 617 
 
 in a current of water, or when they are in some way mechanically 
 rubbed against it. 
 
 An instance of the first kind of action has already been given 
 in the description of hydraulic mining in Chapter VI., and another 
 may be taken from the ordinary stamping mill of most gold 
 mines in which auriferous quartz is being treated. The pulp 
 discharged through the grates of the mortar-box is allowed to 
 flow over an inclined table, covered with a sheet of copper which 
 has been amalgamated. The surface of the copper plate is first 
 very carefully scoured, then cleaned with a solution of cyanide of 
 potassium, and finally rubbed with mercury and a little sal- 
 ammoniac. The bright silvery surface is then capable of picking 
 up the little particles of gold in the pulp and retaining them in 
 the form of a coating of amalgam, which is naturally thickest 
 where the pulp first comes upon the table. When a sufficient 
 thickness has accumulated, the amalgam is scraped off, washed, 
 mixed with a little fresh quicksilver, washed with water, and 
 finally squeezed through canvas or chamois leather. The hard 
 amalgam so obtained is retorted. 
 
 Various devices are in use for making the little particles of 
 gold turn over from time to time and so expose fresh surfaces to 
 the quicksilver, in order to increase the chances of such intimate 
 contact as will ensure amalgamation. Sometimes steps are made 
 in the tables, giving the thin stream of pulp a little drop, some- 
 times the tables are shaken, whilst in the Hungarian mill the 
 pulp flows over the surface of a bath of mercury, the surface of 
 which is lightly skimmed by revolving iron knives. 
 
 Amalgamation will not take place unless the two metals are 
 bright and clean ; any slight film upon the mercury, such as 
 is produced by grease or tarnish, prevents contact, and the little 
 particle of gold rolls or slides down over the plate, just as it 
 would do on a plain sheet of copper, and is liable to escape. 
 The greatest care has therefore to be taken to keep the 
 amalgamated plates clean, and from time to time any tarnish 
 may be removed by brushing them with a solution of cyanide 
 of potassium. Other means of keeping quicksilver bright are 
 the addition of a little sodium amalgam, or the production of 
 nascent hydrogen upon the surface of a mercury bath by the 
 passage of a current of electricity. This is the principle of 
 Molloy's amalgamator, and that invented by Chaster and Beck. It 
 is evident from experiments, when the mercury covered with water 
 is connected to the negative pole of a dynamo, and lead plates 
 forming the anode are connected to the positive pole, that the 
 disengagement of hydrogen does keep the bath constantly bright 
 and lively, and fully entitles the metal to its familiar name 
 " quicksilver." Under these circumstances it takes hold of the 
 gold more readily, but the process does not appear to have gone 
 beyond the experimental stage at present. 
 
618 ORE AND STONE-MINING. 
 
 Considering the ease with which amalgamation is impeded 
 or prevented by a flimsy coating upon the mercury or upon the 
 gold, it is not surprising that rubbing of some kind should have 
 been tried in order to brighten the surfaces of the two metals 
 and so secure perfect contact. It seems probable that when gold 
 was worked by the Romans in the Alps, the precious metal was 
 extracted by rubbing the ore to powder with water and mercury 
 upon slabs of gneiss by stone mullers. Subsequently, no doubt, the 
 quern was pressed into the service of the gold-miner, and by adding 
 a rude horizontal water-wheel to the quern, the hardy Piedmontese 
 miners developed their molinello, or small mill, by means of which 
 large quantities of gold have been obtained. Proceeding one st,*p 
 further, we have the arrastra, the most perfect form of which can 
 probably be seen in Italy, and substituting iron and steel for 
 stone we have the various pans. All these mills perform a double 
 service ; they not only break up the ore and set free the minute 
 particles of gold, but they at the same time scour the gold, 
 make it bright and rub it against the quicksilver. Probably in 
 many cases the gold makes a streak upon the bed, just as it 
 would do if rubbed upon a jeweller's touchstone, and so gives a 
 clean bright surface with which the mercury at once amalgamates. 
 The mills may also be worked as concentrators, for if a stream of 
 water is run through them while they are being driven slowly, the 
 light particles are carried off, and the heavy metallic sulphides lie 
 at the bottom in contact with the mercury, ready to give up the gold 
 they contain as soon as they are crushed fine enough to liberate 
 it. The heat developed by the friction of the muller is consider- 
 able and may assist the process of amalgamation, and indeed it may 
 explain how it is possible to extract 80 percent, of the gold from 
 ores containing 10 to 20 per cent, of iron pyrites by simple amal- 
 gamation in arrastras. The arrastra is a more suitable 
 amalgamator for such ores than the copper plate, but it is a 
 slow grinder and it causes a large loss in quicksilver when raw 
 ore is treated by it. Various other mills are used for the same 
 purpose. 
 
 APPLICATION OP PROCESSES. Having now passed 
 in review the various mechanical, physical, and chemical processes 
 which are employed by the miner in preparing his minerals for 
 sale, it remains to say a few words upon the manner in which 
 they are applied in different cases. Space will not admit more 
 than an outline, nor is it necessary in a general text-book to 
 enter deeply into details. 
 
 For the sake of convenience the various minerals will be taken 
 in alphabetical order. 
 
 Amber. The lumps are separated by washing from the enclos- 
 ing sand, and are sorted according to colour and size. The small 
 pieces are treated in a steam bath at a temperature of 150 with 
 certain re-agents in order to remove the dark rind, and the clear 
 
DRESSING. 619 
 
 kernels which remain are melted up together and sold to the 
 varnish merchants. 
 
 Arsenic. Arsenious acid is obtained by roasting and sublima- 
 tion. The crude arsenic resulting from the treatment of tin 
 "whits" is usually of a dirty grey colour owing to the ad- 
 mixture of solid carbonaceous particles deposited by the smoke ; 
 it is spoken of as " arsenical soot," and is sold by the miner to 
 works where it can be purified by being re-sublimed. 
 
 At some mines, however, which yield large quantities of mis- 
 pickel, the final purification is performed on the spot, and white 
 sublimed arsenic and arsenical glass are prepared by re-sublima- 
 tion, put into barrels and sent out into commerce. 
 
 Asbestos. The dressing of the asbestos (chrysolite) of Canada 
 is simply a process of cobbing i.e., the separation of the valuable 
 mineral from the enclosing serpentine by well-directed blows of 
 the hammer. 
 
 Asphalt. The crude Trinidad pitch is purified or refined on 
 the island by melting it in iron pans and allowing the earthy 
 matter to fall to the bottom. In France the process is some- 
 what different : the crude pitch is boiled with a heavy tar oil 
 obtained from the distillation of shale, in the proportion of 9 
 of pitch to 4 of tar oil. The 30 per cent, of water in the pitch is 
 driven off and a small amount of .earthy matter is deposited, but 
 the refined pitch, consisting of the two ingredients which were 
 mixed, still contains a large percentage of clay. 
 
 Bituminous sandstone * is made to yield up its pitch by melting 
 with water. The sandstone is broken up into lumps about 3 
 inches across, thrown into cauldrons of boiling water, and stirred 
 for an hour. The bitumen melts and rises to the top, whilst 
 the sand falls to the bottom. The bitumen is skimmed off, though 
 it is by no means free from sand, if the original sandstone was fine- 
 grained. It is then re-melted and the sand allowed to sink; 
 the liquid bitumen is drawn off and allowed to cool in moulds, 
 but the sandy deposit at the bottom still contains a good deal of 
 pitch which cannot profitably be separated. 
 
 The treatment of the bituminous limestone of Seyssel has 
 already been described in the general part of this chapter. 
 
 Barytes. The principal processes in preparing barytes for 
 the market are drying and grinding. 
 
 The barytes coming from the mine is washed and picked, and 
 pieces intermixed with rock are cleaned by cobbing. The lumps 
 are dried upon a tiled floor heated by flues underneath, and are 
 then crushed, either by rolls or an edge-runner, to a coarse 
 powder, which is twice ground in mills like flour-mills. French 
 burr stones are preferred. The second grinding yields a powder 
 as fine as flour, which is put up into barrels ready for sale. 
 
 * Malo, L'Asplialte, Paris, 1888, p. 68. 
 
6 20 OIIE AND STONE-MINING. 
 
 Iron-stained barytes is " bleached " by acid, as already ex- 
 plained. 
 
 Borax. The earth obtained at the borax la.ke, California, is 
 ground, and then dissolved in water brought to the boiling 
 point in large iron vats by injecting steam. The contents are 
 allowed to settle, and the clear solution, containing the carbonate, 
 sulphate, chloride, and borate of sodium, is drawn off into pans 
 and allowed to cool. The borax is the first to crystallise out, and 
 the crystals are collected and sold, or are re-dissolved ; this second 
 solution furnishes, on crystallising, the refined borax of com- 
 merce.* 
 
 Boric Acid. The solution of boric acid, obtained in Tus- 
 cany by passing natural steam-puffs (soffioni) through water, is 
 evaporated either by the heat of some of these soffioui, or 
 artificially, until the gypsum and other impurities separate; 
 the liquid is drawn off and the acid is allowed to crystallise 
 out. 
 
 Carbonic Acid. If not at once piped off to white lead or soda 
 works, carbonic acid is compressed and sold in the liquid state. 
 
 Clay. Common clays are used on the spot, and made into 
 bricks, tiles, or drain-pipes. The potter's clay of Devonshire 
 is sent away in cubical lumps just as they come from the pit, 
 but the china clay is obtained by a true dressing process. The 
 stream of water running down the side of the openwork, and 
 carrying with it all the ingredients of the decomposed granite, is 
 led into a pit where the coarse particles of quartz settle,t whilst the 
 clayey water is conducted into long channels in which fine sand and 
 mica are deposited gradually. Lastly, the milky stream reaches 
 circular pits, 20 to 40 feet in diameter, and 6 to 20 feet deep, 
 drops its kaolin, and passes off as almost clean water. The 
 creamy deposit is dried in the manner already described (Fig. 676), 
 and the china clay of commerce is the result. 
 
 Fuller's earth is also a clay which has to be dressed before being 
 sent into the market. The processes to which it is usually sub- 
 jected are drying, sifting, and grinding. 
 
 The clay coming from the pits is dried in kilns (Fig. 677) and 
 sifted by hand to take out the fine, if the customer insists upon 
 having nothing but lumps. The dry lumps are put up into sacks, 
 and the small is sifted again. The very fine, below | inch, is 
 thrown away, and the coarser part is ground to fine flour in an 
 Askham mill, and so sold. 
 
 In addition to this dry dressing, some of the clay is ground in 
 an edge-runner, run into settling tanks, and dried much in the 
 same way as china clay. 
 
 * Napier Hake, " An Account of a Borax Lake in California," Jour. Soc. 
 Chem. Ind., vol. viii., 1889, p. 856; E. L. Fleming, "Borax," Chern. News, 
 vol. Ixiii., 1891, p. 74. 
 
 t Collins, Ike Ilensbarrow Granite District, Truro, 1878, p. 18. 
 
DRESSING. 621 
 
 Copper Ore.* The ores of copper are so different that no 
 general scheme of treatment suitable to all of them can be pre- 
 scribed. Thus, for instance, the copper shale of Man sf eld is 
 merely picked at the mine before going to the smelting works, 
 which receive an ore containing only 2 to 3 per cent, of metal. At 
 the Lake Superior mines concentration by water can be carried 
 to such a pitch that the " barrel copper " leaving the dressing 
 estnblishments often has more than 70 per cent, of metal. 
 
 Hand-picking is generally an important part of the dressing 
 when the ore consists largely of a mineral like chalcopyrite, 
 because it is easily crushed to powder liable to be carried away by 
 water in washing. At the Rio Tinto mines f the following are 
 the principal varieties separated by picking : 
 
 a. Rich ore with 5 cr 6 per cent, of copper, which is smelted on the 
 
 spot. 
 
 b. Lump ore with 2 to 3 per cent of copper, which is exported. 
 
 c. Lump ore with 2 per cent, of copper, which is burnt in heaps on 
 
 the spot. 
 
 d. Fine ore, which is added to the burnt ore, so that its copper 
 
 may be gradually rendered soluble. 
 
 e. Quartzose ore, which is retained for the furnaces. 
 
 When copper pyrites occurs coarsely intermixed with quartz and 
 other earthy minerals, the dressing usually begins with hand-picking 
 and crushing by rolls ; the coarser grains are jigged, and the finest 
 particles are cleaned and rendered rich enough for sale, by buddies, 
 frames, revolving tables, or endless belts. Intermediate products 
 made up of ore and waste have to be re-crushed before a complete 
 separation is possible. 
 
 At the Lake Superior mines, where the mineral is native 
 copper, the treatment is different. The rock from the mine is 
 stamped by huge Ball or Leavitt stamps until it will pass through 
 holes of T %- inch, and the copper-bearing stream is delivered 
 into upward current separators, which make five classes; the 
 four coarsest sizes are treated on Collom jigs, and the fifth upon 
 revolving tables. 
 
 Diamonds. The dressing of the diamond-bearing rock of 
 South Africa J may be divided into the following separate 
 operations : 
 
 a. Natural disintegration, under atmospheric agencies, aided by 
 watering, rolling and harrowing. 
 
 * Egleston, " Copper Dressing in Lake Superior,'* Metallurgical Review, 
 New York, vol. ii., 1878. 
 
 Henderson, " On the Methods generally adopted in Cornwall in Dressing 
 Tin and Copper Ores," Proc. Inst. C. E., vol. xvii., 1857-58, p. 106. 
 
 Rathbone, " On Copper Mining in the Lake Superior District," Tree. 
 Inst. Mech. Eng., 1887, p. 86. 
 
 t Collins, " On the Geology of the Rio Tinto Mines," Q. J. Geol. Soc., vol. 
 xli., 1883, p. 256. 
 
 De Beers Consolidated Mines, Limited, Second Annual .Report, for tho 
 Tear ending 31 st March 1890, p. 19. 
 
622 ORE AND STONE-MININU. 
 
 b. Screening in a revolving screen, with holes i inch by i inch, 
 or i inch by T J, which take out coarse lumps ; these are returned 
 to the depositing floors to undergo the weathering process a little 
 longer. 
 
 c. Washing the fine in rotary pans, which separate clean gravel 
 from the fine sand and mud; the latter flow into another similar 
 washer, where the process is repeated in case any diamonds should 
 have escaped in the overflow from the first. 
 
 d* Screening the clean gravel through a cylindrical sieve, with 
 round holes varying from ^ inch to f inch in diameter, making 
 in all five sizes. The largest grains discarded by the sieve are 
 picked at once. 
 
 e. Treatment in a " pulsator," which is simply a jig with con- 
 tinuous feed and discharge like the Hartz jigs. The bed is formed 
 of leaden bullets. A concentrate, containing the diamond-!, 
 passes through the bed, and refuse goes over the edge of the 
 
 jig- 
 
 f. Picking out the diamonds by hand, first by white men when 
 
 the gravel is wet, and then by native convicts when it is dry. 
 The operation of picking is repeated as often as enough diamonds 
 are found to repay the cost of the labour. 
 
 Flint and Chert. Flints are trimmed into square-faced 
 lumps for building purposes, or are split and trimmed into 
 gun-flints. Chert is trimmed by hammering into blocks for use 
 in the potteries. 
 
 Gold. The precious metal may be extracted from simple sand 
 and gravel by mere washing, or by washing combined with amal- 
 gamation. Hydraulic mining affords an example of the latter 
 method. When the gold is enclosed in hard rock such as quartz, 
 or occurs in a hard tightly cemented conglomerate, the auriferous 
 stone has to be crushed in order to set the metal free. 
 
 The crushing is most often effected by a stonebreaker, followed 
 by stamps, and the pulp is run over amalgamated copper plates. 
 Mercury is often added in the battery so as to catch the coarse 
 gold at once. The amalgam scraped off the plates and taken out 
 of the battery-box is cleaned and retorted, giving spongy gold, 
 which is melted in crucibles and cast into bars. If the ore 
 contains much pyrites or other heavy metallic sulphides, the stuff 
 leaving the amalgamated plates is taken to a dressing machine of 
 some kind, such as a Frue-vanner, which furnishes a concentrate 
 consisting largely of metallic sulphides, more commonly known to 
 miners by their older name of " sulphurets." These are sure to 
 contain gold, and they are further treated in various ways : by 
 direct amalgamation in pans, which means a still finer grinding, 
 to liberate more of the fine particles of gold, by smelting, by 
 chlorination, or by the cyanide process. 
 
 Gold is also extracted by grinding up the ore in mills or arras- 
 tras with water and a little mercury. Excellent results have 
 
DRESSING. 623 
 
 been obtained in Italy by this method, even with highly pyritic 
 ores. 
 
 It is very necessary that the miner should recollect that gold 
 does not always exist in the same state in the ore, and that the 
 value of the ore depends not only upon the amount of metal in 
 it, but also upon the ease with which it is extracted. A mere 
 assay gives information upon the first point only. It tells how 
 much gold there is per ton, but it does not say whether the 
 metal is in the native state, or whether it is combined with some 
 other element which may render extraction by amalgamation 
 quite impossible. Even when the gold is all native, the size of 
 the particles varies considerably, and they may or may not be 
 wrapped up in iron pyrites or other metallic sulphides. Con- 
 sequently it is futile to suppose that all gold ores can be treated 
 by one and the same method. 
 
 Graphite. The graphite of Ceylon is first picked at the 
 mine, and then despatched to Colombo to undergo the processes of 
 cobbing, picking, and screening. Men and women, using a tool 
 like a little axe, chip off the waste material from the lumps, and 
 sift the small fragments upon slightly inclined screens made of 
 sheet-iron. They also clean the lumps with brushes made of 
 cocoa-nut husks. In this manner four different kinds of graphite 
 are produced viz., " large lumps," pieces about as big as the fist 
 or larger ; " ordinary lumps," about the size of walnuts ; " chips," 
 about the size of grains of wheat ; and " dust," which includes 
 everything smaller. The graphite is now ready to be barrelled 
 for export. 
 
 One mode of concentrating certain kinds of graphite has been 
 mentioned as an instance of a method depending upon differences 
 of friability ; but in addition to these dry processes, graphite is 
 also dressed by the aid of water. In Moravia and Bohemia 
 graphite is found in gneiss, and may be intermixed with lime- 
 stone, quartz, iron pyrites, garnets and hornblende. Rock of this 
 kind is pulverised by grinding in mills, or by stamping, and the 
 pulp is made to flow into rectangular wooden boxes in which the 
 coarser particles and part of the rock and pyrites are deposited. 
 The graphite-bearing water passes on into a number of long 
 rectangular wooden troughs (tyes, strips, or strakes, Cornwall), in 
 which the graphite deposits itself gradually, whilst clean water 
 flows out of the last trough. The first trough has the worst 
 graphite, and the last the best quality of the mineral. The 
 deposit is dug out, pressed in filter presses, and the resulting 
 cakes are dried in stoves.* 
 
 Gypsum. The preparation of gypsum for the market resolves 
 
 * Andree, " Der osterreichische und bayerische Graphitbergbau," B. u. 
 7^. Z. t 1890, p. 269. 
 
 Schauenstein, DenJcbucJi des osterreicJtischen Bery- und Huttenwcsens, 
 Vienna, 1873, p. 116. 
 
624 OHE AND STONE-MINING. 
 
 itself into picking, breaking, burning and grinding ; or where the 
 gypsum is required for other purposes than cement making, the 
 burning or baking is omitted. 
 
 In Sussex the waggons coming from the mine are tipped on to a 
 floor, the large lumps are broken up with a sledge hammer, and any 
 pieces much mixed with worthless rock are picked out as useless. 
 The remainder is sent to a stonebreaker, and the broken lumps go 
 either to a baking oven to be made into plaster, to a burning 
 oven if Parian cement is required, or to a grinding apparatus if the 
 gypsum is sold to manure merchants. 
 
 After burning or baking, the product is ground, first by toothed 
 rolls and then under edge-runners. It is now taken up by an 
 elevator, put through a line revolving screen, and is drawn off 
 into sacks. 
 
 Iron. With a substance of small intrinsic value like iron ore, 
 the methods of dressing must be inexpensive if they are to be 
 commercially profitable ; and at the present time it may be said 
 that most of the iron of commerce is obtained from ores which 
 go direct to the smelter without any preparation beyond picking 
 out refuse underground. A few instances of calcination have 
 already been noted, and also the separation of fine ore by a 
 sieve. Iron ore is sometimes washed in order to get rid of 
 adherent clay, and at the mines of North Lancashire some of 
 the haematite, mixed with clay and siliceous matter, is made fit 
 for the blast furnace by crushing and jigging.* 
 
 The same line of treatment is pursued in the dressing works of 
 the Chateaugay Ore and Iron Company, at Lyon Mountain, N.Y. 
 The mine produces magnetic iron ore, the richer parts of which 
 are picked out, whilst the leaner parts, consisting of grains of 
 magnetite disseminated through gneiss, go to the mills for con- 
 centration. This mixed ore is crushed by Blake breakers, and after 
 screening is treated in Conkling jigs.f 
 
 Haematite for fettling puddling furnaces is ground under edge- 
 runners, and that which is used for making castings malleable is 
 carefully screened. Special qualities are picked out for these 
 purposes. 
 
 In this country the supply of magnetic iron ore is insignificant, 
 and consequently we cannot show examples of concentrating by 
 the aid of magnetism, such as may be found in Sweden and the 
 United States, where this method is occupying much attention, 
 as may be inferred from the descriptions of magnetic separators 
 just given. 
 
 Lead.J A few mines produce lumps of galena so pure that 
 
 * J. G. Lawn. 
 
 t Ruttmann, " Concentrating Magnetite with the Conkling Jig at Lyon 
 Mountain, N.Y.," Trans. Amer. Inst. M.E., vol. xvi., 1888, p. 609 ; and 
 E. M. /., vol xlvi., 1888, p. 870. 
 
 J For details consult Bellora, " Etat actuel de la preparation mecanique 
 
DRESSING. 625 
 
 they merely require washing in order to be ready for sale to the 
 smelter or the potter. 
 
 Much of the lead ore from veins is dressed by crushing, 
 sizing and jigging ; the particles under i mm., or at all events 
 under J mm., are treated by revolving tables, percussion ables, 
 endless belts, or buddies. 
 
 The crushing is done first by a stonebreaker and then by rolls. 
 Blende is often associated with galena, but owing to the difference 
 in their specific gravities, a separation can be made by the 
 appliances just mentioned. Products obtained from the jigs 
 consisting of mixed minerals have to be re-crushed, and then 
 treated once more by machinery similar to that used for the 
 original ore.* 
 
 The soft lead -bearing sandstone of Mechernich f crumbles to 
 pieces so easily, that by the time it reaches the dressing establish- 
 ment, after having fallen down in the underground chambers and 
 dropped through shoots into the waggons, most of it is in a fit state 
 for the concentrating machinery. The works are specially designed 
 for treating very large quantities of poor ore consisting almost 
 entirely of galena and quartz sand ; their main feature is the use 
 of the siphon separator (p. 578), by which a very large pro- 
 portion of the stuff is at once concentrated into clean concretions 
 (Knotten) containing about 22 per cent, of lead. This concentrate 
 goes to another establishment, where it is stamped and passed 
 through siphon separators, jigs, revolving tables and round 
 buddies, in order to separate lead ore fit for the furnaces. 
 
 Manganese. The only preparation of the Welsh manganese 
 ore is separating the fine ore under | inch, by sifting in the mine, 
 and picking out of any pieces of waste or very poor rock. 
 
 The Devonshire ore, which consisted largely of psilomelane, 
 was washed and picked, and the " smalls " were jigged. Some of 
 the large ore was crushed ; the coarse part was jigged, and the 
 fine cleaned in buddies. 
 
 Mica. | The rough blocks obtained from the mine are cleaved 
 by means of steel wedges into sheets J inch or less in thickness, 
 and these are cut by the "scriber" into the shapes required for 
 stove windows. There are a very large number of patterns, 
 langing in size from ixitoSxio inches. The cutting is done 
 
 des minerals dans la Saxe, le Hartz et la Prusse Rhenane," Annales des 
 Mines, ser. 8, vol. xx., 1891, p. 5. 
 
 Munroe, " The New Dressing Works of St. Joseph Lead Company, at 
 Bonne Terre, Missouri," Trans. Amer. Inst. H.E., vol. xvii., 1888, p. 659. 
 
 * Sopwith, " The Dressing of Lead Ores," Proc. Inst. C. E., vol. xxx. f 
 1869-70, p. 1 06. 
 
 t Der Bergbau und Hutteribetrieb des Mechernicher JBergwerJcs-Actien- 
 Vereins, Cologne, 1886, p. 10, and Tables II. and III. ; and B. u. h. Z. t 
 1886, p. 476. 
 
 t Phillips, " Mica Mining in North Carolina," Eng, Min. Jour., vol. xlvi., 
 1888, p. 418. 
 
 2 R 
 
626 ORE AND STONE-MINING. 
 
 with a knife along the edges of a template made of iron or tin- 
 plate. The blocks of crude mica yield from T ^ to ^ of cut mica 
 fit for the market. The refuse scraps are now ground np into 
 fine powder and used in the manufacture of wall-paper, tinsel, 
 hair-powder, and lubricants.* 
 
 Nitrate of Soda. The process of extracting the commercial 
 nitrate from the crude caliche has already been sufficiently 
 described, in speaking of the preparation of minerals by solution 
 and crystallisation. 
 
 Ochre. Native ochre is ground under an edge-runner with 
 water, and the product is run into settling pits. Coarse sand 
 settles first, and further away the sediment consists of fine ochre, 
 which is dug out and dried. The ochre deposited by the water 
 coming from cementation pits has simply to be dug up and dried. 
 
 The native umber of Devonshire is stamped and ground under 
 edge-runners ; the umber suspended in water is pumped up and 
 allowed to settle in tanks until it can be dug out. It is then 
 dried in the same way as china clay.f 
 
 Ozokerite. Some of the mineral is brought up in the form 
 of fairly clean lumps which have been picked out underground 
 and put into sacks. These, together with similar pieces picked 
 out above ground and scraped free from dirt, are melted in large 
 semi-spherical open cast-iron pans and boiled. When allowed to 
 settle, the earthy matter falls to the bottom and clean ozokerite 
 floats on the top. This is ladled out into cylindrical moulds, and 
 on cooling furnishes the large loaves of commercial ozokerite. 
 Water is added to the earthy residues at the bottom of the pans, 
 and the whole brought to the boiling-point. Ozokerite rises to 
 the top and is skimmed off, whilst the residues remaining at the 
 bottom, which still contain some 10 per cent, of wax, are sold to 
 dealers who extract it by means of benzine. 
 
 The small stuff coming from the mine which will go through 
 a grating with bars 2 inches apart is put into a tub of water; the 
 wax rises, is skimmed off with a sieve and purified by melting, 
 and the earthy residues are sold, or are stocked until the miner 
 puts up plant for extraction by benzine. 
 
 Phosphate of Lime. The varieties of this mineral are so 
 numerous, from the hard compact apatite of Canada to the pulveru- 
 lent mineral of the Somme district, that the modes of treatment 
 must necessarily be extremely different ; sometimes also the mineral 
 is sold finely ground and put up in sacks ready for the farmer, in 
 other cases the miner satisfies himself with removing all waste, 
 and leaves to other persons such processes as milling or manu- 
 facture into superphosphate. 
 
 * Nitze, " Ground Mica Industry in North Carolina," Eng. Min. Jour., 
 vol. liv. , 1892, p. 292. 
 
 t Frecheville, " The Umber Deposits at Ashbuiton," Trans. It. Gwl. 
 Sue., Cornwall," vol. ix. p. 219. 
 
DRESSING. 627 
 
 As a rule, the treatment may be summed up as drying and 
 grinding, often preceded by a preliminary washing. For instance, 
 the phosphate of the Somme is dried first upon iron-plated floors, 
 and then in a Ruelle stove or a revolving calciner. This prepares 
 it for grinding. The first grinding is done between two vertical 
 stones, and all that is fine enough is drawn out by an exhaust 
 fan j the portion which is too coarse to be sucked up by the 
 current of air passes into a mill with horizontal stones and is re- 
 ground. After being put into sacks it is ready for the manure 
 merchant, or for the farmer if he applies it to his land direct. 
 
 The nodules of the South Carolina phosphate are freed from 
 the sand and clay by a mechanical washer, in the form of a helix 
 revolving i n a trough. The material is fed in at the lower end 
 and is gradually screwed up to the other against a strong stream 
 of water. The water carries away the waste, and clean lumps are 
 delivered at the other end. The washed nodules are dried in 
 kilns and are then ready for export.* 
 
 Potassium Salts. The two principal potassium salts obtained 
 by mining are carnallite and kainite. Simple grinding is often the 
 only preparation before sale, but in some cases, as explained on 
 page 608, the carnallite undergoes a complicated treatment by 
 solution and crystallisation, for the purpose of extracting chloride 
 of potassium and utilising the by-products obtained in these 
 processes. 
 
 Quicksilver. The great intrinsic value of quicksilver ore 
 enables hand-picking to be carried further than would be 
 compatible with a mineral of little worth. At Idriaf the loss of 
 mercury was so great under the old system of wet dressing, 
 in spite of the high specific gravity of cinnabar, that this 
 method was given up some fifty years ago. Nowadays, the 
 preparation for the smelting is done solely by crushing, sizing, and 
 hand-picking. The stuff broken in the mine is separated under- 
 ground into waste, poor ore and rich ore. The first is left in the 
 workings, and the two kinds of ore are tipped separately on to a 
 grating with holes of 4 inches (100 mm.) across. The coarse 
 lumps are crushed by Blake's stonebreakers, and the broken ore 
 which is too big to pass through holes of | inch (20 mm.) is 
 hand-picked ; the portions so separated are made ready for the 
 smelting works by further crushing. When poor ore is being 
 treated, waste can be picked out and thrown away at once. The 
 stuff passing through the 20 mm. mesh is crushed by rolls and 
 sent to the smelting works. 
 
 The "smalls" which passed the 100 mm. grating are screened 
 on a 2-inch (50 mm.) sieve; the coarse goes to the stonebreaker 
 and the fine to screens of different sizes. All that is over inch 
 
 * Benedict, " Mining, Washing, and Calcining South Carolina Phosphate," 
 
 ncj. Min. Jour., vol. liii., 1892, p. 349. 
 
 f Das k. k. Quecksilbenverk zu Idria in Krain, Vienna, 1881, p. 19. 
 
6 2 3 ORE AND STONE-MINING. 
 
 (20 mm.) is picked, and some waste taken out; what is under 
 this size is passed through the rolls and so made fit for the 
 furnaces. 
 
 Salt. The mode of making a saleable product from brine has 
 already been described ; but it must not be forgotten that brine 
 itself is sold as such to works which make alkali by the Solvay 
 process. 
 
 Some rock-salt is prepared for the market by crushing. At 
 one of the Cheshire mines there are three pairs of crushing rolls 
 one above the other, the first pair coarsely fluted, the second pair 
 fluted, but less coarsely, and the third or lowest pair smooth. The 
 rolls are from 18 inches to 2 feet in diameter and 2\ feet long. 
 The rolls of another crusher are made up of toothed ring* 
 threaded upon shafts, and so arranged that the teeth of one roll 
 fit between two of the rings of the opposite roll. Some of the salt 
 is also ground by a disintegrator. 
 
 Silver. The ores of silver may be divided into two classes : 
 silver ores proper and argentiferous lead and copper ores. 
 
 Many of the silver minerals are very friable, and are liable to be 
 carried off with the refuse, if subjected to the ordinary wet dress- 
 ing processes ; the preparation of such ores at the mine is gene- 
 rally limited to crushing, picking, and cobbing. The mirier then 
 relegates to others the task of extracting the precious metal by 
 methods based upon its affinity for quicksilver or molten lead, or 
 upon the leaching properties of hyposulphite of soda. 
 
 Argentiferous lead and copper ores are concentrated by the 
 processes in vogue for the baser metals ; but if the proportion of 
 silver is large, a greater amount of labour may be expended upon 
 hand-picking and cobbing than would be permissible with ores of 
 lead and copper alone. 
 
 Slate. Two articles of commerce are made at the quarries : 
 roofing slates and thick slabs used for cisterns, billiard-tables, 
 and tombstones. The slate arrives at the surface in the form 
 of large blocks, often weighing two tons or more. These are 
 divided by splitting into slabs about 3 inches thick, which go to the 
 sawing tables. The circular saws cut up the slabs into pieces 
 suitable for the operation of fine splitting ; by the careful and 
 dexterous use of his wedge and mallet, the quarryman is able to 
 split the slab into thin sheets, which at Festiniog often do not 
 exceed \ inch in thickness. These have to be trimmed, generally 
 into a rectangular form. Though this operation can be and 
 often is performed by hand, it is more common to use some 
 kind of knife worked by machinery (Fig. 639). The slates are 
 then sorted by hand according to their quality. The slabs are 
 first split out of blocks, and are finished by being sawn into shape 
 and planed smooth by machinery. 
 
 Stone. It is impossible in a general treatise to enter into any 
 details concerning the preparation of stone at mines and open- 
 
DRESSING. 629 
 
 works. Some stone is shaped by hammering, into paving blocks 
 or " setts " ; much is crushed by stonebreakers and sold as road- 
 metal after removal of the fine by screening ; freestone is sawn so 
 as to suit the builder ; flags are obtained by splitting micaceous 
 sandstone along the planes of bedding and trimming the edges, 
 and, lastly, gunflints are made from the well-known nodules by 
 the dexterous chipping of the " knapper." 
 
 Sulphur. This element is obtained from the rock, which 
 contains it in the native state, by simple liquation in a kiln of 
 some kind, intermittent (calcarone) (Fig. 677) or continuous (Gill's 
 furnace), by liquation in steam -heated cylinders, or by distillation 
 in iron retorts ; this last process, which was at one time practised 
 with rich ore in the Romagna, is now almost entirely abandoned. 
 
 Tin.* The tin ore obtained from veins usually contains 
 the cassiterite so finely disseminated through the stone, that a 
 considerable amount of comminution is required before the valu- 
 able grains are thoroughly liberated, and so rendered capable of 
 being separated by washing. In Cornwall the first process is a 
 preliminary crushing by a Blake's stonebreaker, followed by 
 stamping until the pulp will pass through a fine grate. The pulp 
 is led into round buddies in order to produce a first concentrate, 
 containing not only all the cassiterite, but also the iron pyrites, 
 mispickel and other metallic sulphides with which it is so often 
 associated. By repeating the operation of buddling, a concentrate 
 is obtained, which is subjected to " tossing and packing " in order 
 finally to prepare it for the furnace. This first concentrate, known 
 in Cornwall by the name of whits, is dried upon the top of the 
 calciner and then roasted in the manner already described. After 
 roasting, the buddling is repeated, and, lastly, the tossing and 
 packing, with the result that clean tin ore with 65 to 70 per cent, 
 of metal can be put away in bins, ready to be done up in sacks 
 and despatched to the smelting works. In some cases the ore is 
 not contaminated with sulphides, and no roasting is required. 
 
 The tin-bearing sand and gravel, which have furnished and are 
 still furnishing such a large proportion of the world's supply of the 
 metal, can be treated in a speedier fashion. The wash-dirt is 
 simply shovelled or hoed against a stream of water in a ditch or 
 trough ; the light waste is washed away, and the heavy pebbles 
 and clean grains of cassiterite are left at the head. This is the 
 method usually employed in the East. 
 
 The tin-gravel worked at Restronguet Creek,f near Truro, was 
 w.ashed with water in order to separate adherent clay, and then. 
 
 * Ferguson, " On the Mechanical Appliances used for dressing Tin and 
 Copper Ores in Cornwall," Proc. Inst. Mech. Eng., 1873, P- "9 J Henderson, 
 "On the Methods generally adopted in Cornwall in dressing Tin and 
 Copper Ores," Proc. Inst. C.E., vol. xvii., 1857-58, p. 106. 
 
 t Taylor, " Description of the Tin Stream Works in Restronguet Creek, 
 near Truro,'' Proc. Inst. Mccli. Eny.> 1873, p. 161. 
 
630 OHE AND STONE-MINING. 
 
 passed to a revolving sieve. The fine stuff was jigged, and finally 
 cleaned by a propeller-knife buddle ; the large pebbles were 
 picked over, and those containing tin were stamped and treated 
 like vein rock. 
 
 At Mount Bischoff,* in Tasmania, the process of dressing may 
 be briefly summed up as follows : Comminution by stamps, and 
 extraction of the tin ore from the pulp by jigs and revolving 
 tables. 
 
 Zinc. Calamine has sometimes to be washed, in order to rid 
 it of clay, before it is crushed and jigged like lead ore. 
 
 Blende is dressed in the same way as lead ore, and is often ob- 
 tained from one compartment or portion of a dressing machine, 
 whilst galena is being discharged from another. 
 
 LOSS IN DRESSING. 
 
 The loss in dressing is frequently very great, and proofs of this 
 fact constantly come under one's notice. Old heaps of mining refuse 
 left by former workers may be seen yielding an abundant harvest 
 to a later generation, and even with the machinery of to-day the 
 extraction is far from perfect. For instance, in the year 1891 no 
 less than 879 tons of dressed tin ore, worth ^33,704, were ex- 
 tracted from the muddy water discharged into the " Red River " 
 and its tributaries by some of the large tin mines near Camborne 
 and Redruth. 
 
 The loss is due to several causes. First comes imperfect 
 severance of the valuable mineral from the worthless constituents 
 of the ore during the crushing process this is unavoidable if the 
 mineral occurs in the state of very minute particles. Secondly, 
 the thickness of the dirty water escaping from the machines, 
 which impedes the subsidence of the fine grains; thirdly, want of 
 care on the part of the persons placed in charge of the machinery. 
 In addition to these causes, which are general, special reasons ac- 
 counting for loss will be found with certain minerals: the 
 amalgamation of gold is prevented by grease, by any coating or 
 film upon it which impedes close contact with the mercury, by the 
 presence in the ore of substances which have an injurious effect 
 upon the mercury, " sickening " it, or in other words depriving it 
 of its natural activity. Again, if the mineral is flaky, it will not 
 fall so easily in water as if the particles more nearly approached 
 a spherical shape. 
 
 The actual loss has been very carefully ascertained in some 
 cases, though less attention is paid to exact determinations than 
 the subject deserves. M. Bellomf cites three cases of loss at mines 
 producing argentiferous galena and blende. 
 
 The ore delivered to the Himmelfahrt Works, near Freiberg, 
 
 * Kayser, "Advantages of Ore-tlressirg by Automatic Machinery," 
 Trans, JUin. Assoc. and Inst. Cornwall, vol. ii., i8S8, p. 51. 
 f Op. cit., p. 624. 
 
DRESSING. 631 
 
 contains 2J per cent, of lead, 0*275 percent, of zinc, and 7*3 ozs. 
 of silver per metric ton (23 grammes per 100 kil.), besides a 
 little copper, -J- per cent, of arsenic, and 5 per cent, of sulphur. 
 The galena is dressed to 85 per cent, of lead and 96 ozs. of silvei 
 (300 grammes per 100 kil.), the blende to 40 per cent, of zinc and 
 9 -6 ozs. of silver (30 grammes per 100 kil.), the pyritic minerals 
 to 40 per cent, of sulphur and 16 ozs. of silver (50 grammes 
 of silver per 100 kil.). The losses are found to be 21 per cent, of 
 the silver, 38 per cent, of the lead, and 60 per cent, of the 
 sulphur. 
 
 At the Churprinz Works, also near Freiberg, the raw ore con- 
 tains 3 per cent, of lead, and 3 ozs. of silver per metric ton (9^ 
 grammes per 100 kil.), and a dressed product is prepared with 
 70 per cent, of lead and 16 ozs. of silver per ton (50 grammes 
 of silver per 100 kil.). The loss in dressing is 22*8 per cent, of 
 the silver and 14-9 per cent, of the lead. 
 
 The ore treated at Ems contains 4 per cent, of lead, 2 J- per cent, 
 of zinc, and 1*7 ozs. of silver per metric ton (5-4 grammes per 100 
 kil.), but the enrichment by washing is not carried so far as at the 
 other works. The galena is dressed to 36 per cent, of lead and 
 9 6 ozs. of silver per metric ton (30 grammes per 100 kil.), and 
 the blende, which is not argentiferous, to 44 \ per cent, of zinc. Tho 
 losses are 8 per cent, of the silver, 6 per cent, of the lead, and 34 
 per cent, of the zinc. 
 
 It is to be regretted that so many dressing establishments in 
 this country are working entirely in the dark, and are, therefore, 
 utterly ignorant of the losses that are going on. 
 
 At few places in the world is the loss more carefully studied 
 than at the mines of the Pestarena Company in Northern Italy, 
 for a sample is taken from every waggon of crushed ore before it 
 goes to the mills. The quantity of gold in the ore treated can, 
 therefore, be ascertained with great accuracy, and by comparing 
 this amount with the quantity extracted, it is found that about 
 one-fifth escapes amalgamation and is lost; the ores sometimes 
 contain 10 to 20 per cent, of pyrites. 
 
 Another kind of loss which requires to be ascertained is the 
 purely mechanical waste in preparing stone for the market. In 
 the case of slate it is very large, for the blocks brought from 
 the workings into the mills frequently yield only 25 per cent, of 
 roofing material. As the amount of rubbish produced in getting 
 out the blocks is also considerable, the quantity of saleable slate is 
 often only one-twelfth of the actual rock excavated. 
 
 Seeing that the proportion of waste material, whether in ore 
 mines or stone mines, is usually large, it behoves the miner in 
 laying out his dressing establishment, to make provision for the 
 disposal of great quantities of refuse. 
 
632 ORE AND STONE-MINING. 
 
 SAMPLING-. 
 
 The miner may have to sample the produce of his mine for a 
 variety of reasons. Sometimes sampling is necessary in order to 
 ascertain the amount of money due to the workmen ; it is indis- 
 pensable when the loss in dressing has to be ascertained, and, 
 lastly, the miner, after preparing his various products for sale, 
 requires samples for possible purchasers. 
 
 Sampling may be done by hand or by machinery. Four methods 
 of hand-sampling may be mentioned : 
 
 HAND-SAMPLING. i. Sampling by taking out small 
 lots. If the mineral is in coarse lumps and the valuable ingredient 
 irregularly distributed, picking up a few stones here and there 
 is not likely to yield a very correct sample ; but, on the other 
 hand, if the mineral is already crushed, and if the small lot 
 is taken regularly, say for instance every tenth shovelful, it is 
 possible to obtain great accuracy. Thus at the Pestarena mines 
 the gold ore before being milled is crushed by rolls until it will 
 pass a sieve with three holes to the inch ; and from each waggon 
 of crushed ore about 2 kilos, are taken by a tin measure. The 
 load is spread out horizontally with the hand and a tin measure 
 is filled from this flat surface and thrown into a tub. Each 
 waggon is weighed, and the 2 kil. represent about ^Ju^n f the 
 load. At the end of the day the tubt'ul is taken as the sample of 
 the stuff sent to the mills. From this large sample a small one 
 is prepared by the process of quartering, which will be described 
 immediately. 
 
 This method of sampling will also suffice in the case of an ore 
 of small intrinsic value, such as an iron ore, consisting in the 
 main of one mineral. 
 
 2. Trenching. In order that this method of sampling may 
 be accurate, it is necessary that the mineral be well mixed, and 
 where a valuable ore is concerned, great care is expended upon 
 the operation. It may happen that there are a number of small 
 heaps of dressed ore, each produced by a different gang of men, 
 which have to be mixed before being sold in one lot. The stuff 
 from the first heap is spread out evenly on a smooth flat floor. 
 Layer after layer is added from the other small heaps until 
 a large square or rectangular pile is obtained made up of 
 horizontal strata. The mixing is now carried out by taking 
 off a slice from the side of the heap with a shovel, so as to 
 cut through all the layers ; the stuff is tossed on to the floor 
 and spread over a large area, and the thorough intermingling 
 is aided by a boy who stirs it as it falls. The original heap is 
 cut away slice after slice, and gradually, at the side of it, another 
 heap is formed with the particles thoroughly mixed, which is ready 
 for the operation of trenching ; it may be, for instance, 10 ft. wide 
 by 15 ft. long, and 18 inches high. If the operation of turning 
 
DRESSING. 
 
 633 
 
 over and mixing was carried on along the long side of the rectangle, 
 a couple of trenches are dug across the heap at right angles to 
 this direction, or in other words parallel to the short sidesi The 
 trenches are cut down to the bottom, and after they have been 
 carefully swept out, the sampler slices off small portions of the 
 sides with his shovel. All that he cuts down in this way is 
 shovelled into hand-barrows, and constitutes the large sample, 
 which has simply to be reduced in bulk by quartering. 
 
 With coarsely broken mineral the part shovelled out in making 
 the trench is often taken as a first sample and not the thin slices 
 from the sides, as is done with fine material. 
 
 The two trenches are sometimes cut at right angles to one 
 another, forming an ordinary cross, or along the diagonals, forming 
 a St. Andrew's cross, and the heaps are often round instead of 
 being rectangular. 
 
 (3) Quartering. Quartering is a process of dividing a given 
 lot of mineral again and again until a sufficiently small sample 
 remains. The mineral is made into a conical heap by letting each 
 
 FIG. 695. 
 
 FIG. 696. 
 
 shovelful which is emptied fall down evenly over the apex of the 
 cone. The apex is pressed down, and the heap is spread out till 
 it forms a low truncated cone, a cross is marked upon it with 
 the point of the shovel, and the two opposite quarters, say 
 
 1 and 3 (Fig. 695), are scraped aside and discarded, leaving 
 
 2 and 4, or one-half of the original sample. These two 
 quarters, 2 and 4, are mixed by hand, a new conical heap 
 made and the quartering repeated. The next time the sampler 
 will retain the quarters i and 3, and put aside 2 and 4. If the 
 mineral is not fine, it should be crushed once or twice and put 
 through a finer sieve during the process. In this manner a large 
 sample is reduced sufficiently in bulk, to give the miner a small 
 lot which is a fair average of the whole. 
 
 (4) Sampling Shovel.* This implement is designed for 
 the purpose of obtaining an average sample of a heap of 
 mineral by merely shovelling it over. It consists of a flat 
 rectangular plate with vertical sides (Fig. 696), and two vertical 
 partitions which enclose a central compartment occupying one 
 fourth of its area. This compartment is closed at the back or 
 handle end, whilst the rest of the plate is open. After the 
 
 * Eng. Min. Jour., vol. li., 1891, p. 718. 
 
634 ORB AND STONE-MINING. 
 
 shovel has been filled by a thrust into the heap of finely crushed 
 mineral, it is easy to discharge the outer three-fourths of its con- 
 tents over the back end, and then, turning it over, to deposit 
 the central quarter in a separate place as the sample. 
 
 MACHINE SAMPLING. While we have generally been 
 content on this side of the Atlantic to go on with the old- 
 fashioned methods of hand-sampling, much ingenuity has been 
 displayed in the United States with the object of producing 
 machinery for doing the work, and thereby saving time and 
 labour, to say nothing of furnishing more accurate results. 
 
 According to the principle upon which they work, sampling 
 machines may at once be divided into two great classes : * 
 
 (1) Machines which take part of the stream of material for the whole 
 
 of the time. 
 
 (2) Machines which take the whole of the stream of material for part 
 
 of the time. 
 
 (i) In the former class a spout or opening of some kind is 
 arranged so as to divert part of the stream of ore, coming from a 
 crusher for instance, into a separate receptacle. 
 
 Two samplers used some years ago in Colorado belong to the 
 first class. One of them is a hollow cone with four large holes ; 
 the stream of crushed ore falls upon the apex, and the particles 
 spreading themselves out slide down over the steep surface. The 
 path of some of the particles leads them to the holes, where they 
 drop through, forming a sample of the whole. The size of the 
 holes can be arranged so as to extract a given percentage of the 
 total quantity, and this first sample can be reduced in bulk by a 
 second passage over the cone. 
 
 In the other the desired result is obtained by letting the ore 
 fall on to three inclined shelves one above the other. f Each shelf 
 has openings which allow a portion of the ore to drop through. 
 The ore dropping through the first shelf falls upon the second, 
 which in its turn eliminates part and lets the remainder drop on 
 to the third shelf, where the process is repeated. The portion 
 which has passed through the three shelves constitutes the 
 sample. 
 
 Clarkson's Rapid Sampler, an English machine (Fig. 697), 
 consists of a revolving conical hopper, supplied with the mineral, 
 which runs through a hole in the bottom, and drops on to the 
 apex of a cone. In the path of the falling stream of mineral, 
 now converted into a hollow rotating cylinder, there are two 
 segmental spouts, which intercept any desired proportion of it, 
 and so furnish two independent samples. The size of the spout 
 determines the percentage which is diverted as a sample. 
 
 * Bridgman, "A new System of Ore-sampling," Trans. Amer. Inst. M.E., 
 vol. xx., 1891, p. 416. 
 
 t Egleston, "Sampling Ores in Colorado," Engineering, vol. xxii., 1876, 
 P- 495- 
 
DRESSING. 
 
 635 
 
 (2) In the second class the whole stream is deflected at regular 
 intervals, and this method has the advantage of ensuring the 
 proper proportion between the fine and the coarse, which cannot 
 always be attained by the fixed spout ; where the constituent 
 minerals vary in friability the accuracy of the result must de- 
 pend upon this proportion being strictly maintained. In 
 Brunton's* sampler the stream of ore falling down a vertical 
 trough is diverted to one side or the other by a partition which 
 is moved backwards and forwards by very simple machinery. 
 There are means of regulating the proportion of the time during 
 which the stream is being turned into the side for receiving the 
 sample. 
 
 Bridgman's ore-sampler f has the advantage of supplying two 
 
 FIG. 697. 
 
 FIG. 698. 
 
 FIG. 699. 
 
 absolutely independent samples, and it divides them as often as 
 desirable previous to a recrushing. 
 
 The work is begun by a horizontal revolving wheel formed of 
 two concentric rings, with vertical partitions dividing it into 
 eight segments (Fig. 698). Underneath this first " apportioner," 
 as it is called by the inventor, comes a second one (Fig. 699) ; it is 
 a funnel with openings, a, 6, c, d, on the side, and is made to 
 revolve in the opposite direction to the first. It is succeeded by 
 a third of similar construction. The ore is fed from a pipe on to 
 some point of the first apportioner, and each segment necessarily 
 receives one-eighth of the stream ; segment No. i has a spout 
 which travels round the outer circumference of the apportioner 
 below it, passing over the holes a and 6, whilst the spout of No. 
 
 * "A new System of Ore-sampling," Trans. Amer. Inst. M.E., vol. xiii.. 
 1885, p. 659. t Op. cit. 
 
636 ORE AND STONE MINING. 
 
 5 takes an inner path, including the holes c and d ; the spouts 
 of 2, 3, 4, 6, 7, and 8, deliver their ore into the centre C. One- 
 eighth of the stream from the spout of No. i drops through a and 
 another eighth through b ; the rest falls on to the parts A and 
 B of the funnel and is discharged into the centre. Likewise 
 the original one-eighth from spout 5 drops in part through 
 c and d, and in part on to A and B. The portion passing 
 down through a and b, or through c and d, is therefore one- 
 quarter of one-eighth, or one-thirty-second, of the original bulk. 
 The third apportioner again collects one-quarter and discards 
 three-quarters of each of the two samples coming to it, so that the 
 final samples furnished by the machine are both yi-g- cf the total. 
 These first samples are then recrushed and passed through 
 another machine of sim^ar construction but giving only one 
 sample. 
 
 Mr. Bridgman has likewise devised a small sampler for use in 
 the laboratory. 
 
CHAPTER XIY. 
 PRINCIPLES OF EMPLOYMENT OF MINING LABOUR. 
 
 Modes of payment, according to time, measure or weight ; tribute 
 systems. 
 
 PERSONS employed at mines may have their wages reckoned in one 
 of four different ways : 
 
 1. By time. 
 
 2. measure or weight. 
 
 3. a combination of Nos. I and 2 systems. 
 
 4. value of the mineral obtained. 
 
 (i) The first system is largely adopted for surface labour, 
 such as is required on the dressing floors. Enginemen, stokers, 
 millmen, smiths and carpenters are likewise paid so much a 
 day of a stated number of hours. A time-book is kept, and 
 the wages are reckoned up at the end of the week, fortnight, 
 or month by a simple multiplication sum. For true mining 
 or quarrying that is to say, for excavating valuable mineral 
 and removing worthless rock this system is far less common 
 than the other three. There are objections to it both on 
 the part of mine-owners and on the part of many of the men. 
 The owner has to employ more foremen to look after the work, 
 and an amount of supervision which would be sufficient at the 
 surface is utterly inadequate below ground, because the working 
 places are not within sight from any one point, and can only be 
 reached by traversing low and tortuous passages, or by climbing 
 down and up ladders. The men, too, in many cases prefer to be 
 paid on some system which gives the skilled and steady miner 
 the advantage of deriving some profit from his exertions, over and 
 above the average daily wage he would receive if time were the 
 only standard for good and bad workers alike. 
 
 In rare cases persons are hired for the day only ; this is done 
 sometimes at the ozokerite mines at Boryslaw, where the agent 
 picks out in the morning as many men as he wants from those 
 assembled at the top of the pit. 
 
 In new countries or districts, payment of miners by the day 
 may be necessary at first, because the work is so strange that 
 the men are afraid to enter into contracts, which would appear 
 perfectly reasonable and satisfactory to them if they had been 
 
638 
 
 OHE AND STONE-MINING. 
 
 used from boyhood to this system of arranging earnings. 
 After the more enterprising men have learnt by actual practice 
 what they are capable of doing, they drop into the contract 
 system, and in due course of time the others follow them. 
 
 (2) Much of the work at mines is regulated by a system of 
 piecework of some kind, calculated by measure or by weight. 
 In Cornwall and some other districts, work done in this fashion 
 is known as " tutwork." No doubt the original meaning of the 
 word was "dead work," from the German word " todt," because 
 preliminary and unremunerative work was paid for in this manner ; 
 nowadays the meaning of the term is extended, and it includes 
 the excavation of ore. In driving a level, for instance, the man- 
 ager specifies that the height shall be 7 feet and the width 5 feet, 
 and agrees to pay so many pounds for every yard or fathom of 
 advance. As a rule the mine-owner provides all the necessary 
 materials, and deducts their value at the end of the contract. 
 An example or two will make the system plain. 
 
 THE ADVENTUKE MINING COMPANY, LIMITED. 
 
 Tutwork pay for the Month of May 1886. 
 
 JOHN SMITH AND PARTNERS. 6 Men. 
 
 Amount. 
 
 Fms. 
 
 Sinking 4 
 Stoping 2 
 Putting in 9 stulls . . . 
 
 Ft. 
 
 In. 
 
 Price. 
 
 
 
 8. 
 
 6 
 o 
 
 10 
 
 16 
 
 2 
 13 
 
 d. 
 
 2 
 
 
 
 
 
 I40/- 
 6o/- 
 IO/- 
 
 4 
 
 8 
 o 
 
 
 
 8 
 
 10 
 
 40 
 
 27 
 13 
 
 DEDUCTIONS. 
 
 Cash on account . , . . 
 Candles, 72 Ibs. at ^d 
 
 
 
 
 21 
 I 
 
 I 
 I 
 
 s. 
 O 
 
 4 
 13 
 13 
 14 
 
 18 
 
 d. 
 
 o 
 o 
 
 4 
 4 
 
 2 
 O 
 
 Dynamite, 20 Ibs. at is. Sd. 
 
 
 Shovels, at 2s 
 
 
 Doctor and club 
 Balance . . 
 
 . . t 
 
 10 
 
PRINCIPLES OF EMPLOYMENT. 639 
 
 The meaning of this pay-bill is that John Smith and five other 
 men took a contract to sink a certain shaft at 7 per fathom, 
 and to stope part of the lode at $ per fathom. They sank the 
 shaft 4 fathoms 2 feet, and stoped away 2 fathoms ; in addition 
 to this they put in some timber, a matter not included in the 
 original contract, and for which they are credited with ^4 los. 
 extra. The gross balance due to them is therefore ,40 i6s. &d., 
 against which they are debited with the cost of the candles and 
 explosives supplied to them, and with their subscriptions for 
 medical attendance and accident club. While the contract 
 was running they received 2 1 on account, so that on the pay- 
 day they took up a balance of ,13 13*. iod. In a contract 
 of this kind the leading man, John Smith, is known as the 
 " taker." 
 
 In stoping a vein, the price is calculated per square fathom of 
 advance for its whole width ; thus if a lode is 4 feet wide, stoping 
 i fathom of ground means the removal of a block 6 ft. high 
 6 ft. long and 4 feet wide ; in other words, 144 cubic feet. In wide 
 lodes the men are sometimes paid per cubic fathom excavated. At 
 one British lead mine, where the lode sometimes measures several 
 fathoms from wall to wall, a standard price is arranged for a 
 width of 6 feet, and where the stopes are wider than this the 
 men are paid extra. In order to prevent loss of ore through 
 carelessness, the men are paid a premium of 155. a ton for all the 
 lead ore they save. 
 
 Another example (p. 640) gives an instance of " tutwork " wages 
 calculated by weight. It is copied from the figures on the back of 
 the little envelope in which the money is handed to the "taker " on 
 the pay-day. The account shows that Richard Williams and his 
 six partners excavated 120 tons 9 cwt. of tin ore (" tinstuff") 
 at 6s. per ton, and were credited with ^36 2s. Sd. Against this 
 they had to pay ^5 45. ^d. for materials (candles, explosives, &c.), 
 75. for doctor, 55. $d. for club and is. yd. for barber,* leaving a 
 balance of ^30 45. qd. to be divided among them, that is to say 
 ;i is. yd. per man per week. 
 
 A third basis of payment is the number of inches bored in the 
 shift. This plan was in vogue in stoping the wide lead-lodes in the 
 Upper Hartz some years ago ; it necessitated careful supervision, 
 for otherwise the men bored their holes in the softest places they 
 could find, or in positions enabling them to wield their hammers 
 with the greatest ease, without any thought for the work required 
 from the shots. A foreman came round at the beginning of the 
 shift, and pointed out how the holes were to be placed ; in the 
 middle of the shift he returned, measured the depths bored, and 
 then charged and fired the holes while the men rested. The 
 positions for fresh holes were then indicated, and at the end of 
 
 * The item "barber," a charge of yl. per man per month, still remains 
 in a few of the oldest mines in Cornwall. The barber attends at the 
 mines on Saturdays. 
 
640 
 
 ORE AND STONE-MINING. 
 
 the shift the depths were measured and booked, previous to the 
 charging and blasting. The price paid was i M. 38 Pf. per 
 metre of hole bored upwards, and i M. 13 Pf. per metre of hole 
 bored downwards ; in the latter case the men could put water in 
 the holes, which keeps the finely powdered rock in suspension and 
 allows the cutting edge of the tool to do better execution. 
 
 The men working away the great pyrites deposit at Rammels- 
 berg in the Lower Hartz by means of boring machinery are paid 
 
 WHEAL CHANCE. 
 
 EICIIAKD WILLIAMS AND PARTNERS. 
 
 Pay for 4 weeks ending 27th May. 
 Paid loth June 1893. 
 
 TUIWOBK. 
 
 Fms. 
 
 Ft. 
 
 Ins. 
 
 Price. 
 
 
 
 8. 
 
 i 
 
 Driving 
 Sinking . . . 
 Rising . , 
 
 Stoping . . 
 Stems 
 
 Subsist 
 Materials 
 Doctor, Club, and Barb 
 
 Balan 
 
 
 
 
 61- 
 
 36 
 
 2 
 
 8 
 
 Tons. 
 
 Cwts. 
 
 120 
 
 9 
 
 er . 
 ce 
 
 
 
 s. 
 
 d. 
 
 5 
 
 18 
 
 4 
 
 5 
 
 4 
 
 4 
 o 
 
 
 
 
 30 
 
 4 
 
 4 
 
 per metre of hole bored, as this method is more convenient than 
 measuring up the amount of "ground" removed in wide work- 
 ings and paying per cubic metre. The latter system, however, is 
 adopted in driving levels and sinking shafts where the dimensions 
 of the excavation are regular. 
 
 In removing overburden, where everything has to be sent away 
 indiscriminately, payment per cubic yard excavated is common, 
 just as it is in making railway cuttings ; this system is adopted 
 with the men who uncover the iron ore in Northamptonshire 
 (Fig. 324), whilst those employed in getting the ore are paid so 
 much per ton put into the waggons. 
 
PRINCIPLES OF EMPLOYMENT. 641 
 
 (3) The combination of the two methods, payment by time 
 and payment by measure or weight of some kind, may be adopted 
 when men are too inexperienced or too timid to take contracts 
 depending solely upon results. This plan has been found to 
 answer at a pyrites mine in North Wales, where the mineral is 
 got by the aid of rock drills worked by compressed air. The 
 miners receive a fixed wage of a pound per week and a premium 
 of a penny per foot for every foot bored over 12 feet per day of 
 eight hours. The company finds the machines and all tools. 
 The mine is worked in three shifts of eight hours each ; in two of 
 them the men are merely boring, and in the third shift a set of 
 blasters come round to charge and fire the holes. Of course, as in 
 the Hartz, the position of the holes is planned by the foreman. 
 By working in this way the men generally make from 35. to 45. a 
 week extra pay, for they are able to bore 40 or 50 feet a week 
 more than the standard task. The ore is fairly uniform in hard- 
 ness, for otherwise it would be impossible to maintain a single 
 tariff for the whole of the mine. This system has been advan- 
 tageous both to the men and to the company. Previous to its 
 introduction the men were all on one dead level, and had no 
 interest in exerting themselves ; they each got their jQi a week 
 by doing the minimum amount which enabled them to escape a 
 scolding from the foreman, whilst now the man who works hard 
 feels that he will get some recompense for his extra exertions. 
 The company benefits by having an increased output at a smaller 
 cost per ton, without any extra plant. 
 
 (4) We now come to the fourth or last system viz., payment 
 by value of the product. This system has had its home in the 
 south-west of England for many years, and has been transplanted 
 by the ubiquitous Cornish man to many other ore-mining districts. 
 In Cornwall it is known as working on " tribute." 
 
 Under the tribute system a gang of men agree to hand over 
 to the mining company all the ore they raise, on condition that 
 they receive a certain proportion of its value. Thus, supposing 
 that the tribute is J, or 55. in the^i, and that a couple of men 
 produce marketable copper ore worth ^50, their share will be 
 ^50 -r J or 12 i os., less the cost of the materials they have 
 been supplied with, and all the expenses for winding, dressing, 
 sampling, &c. In other words, the tributer may be said to take a 
 sublease of part of the mine and pay a royalty, in this case of J 
 or 75 per cent, for the permission to work accorded to him. But 
 it must be recollected that the mining company renders the place 
 accessible to him, keeps it drained and ventilated, and supplies 
 him with machinery for raising his ore to the surface and dressing 
 it, which he could not provide. The tributer is therefore a 
 person who can speculate upon the value of the ore in a certain 
 small working area, without having any capital beyond his brain 
 and his muscle. 
 
 2 s 
 
642 
 
 OEE AND STONE-MINING. 
 
 The precise nature of this mode of payment will be best under- 
 stood by an actual example. 
 
 John Jones and Partners, 
 
 WHEAL CHANCE. 
 
 Pay for 4 weeks ending 27th May. 
 
 Paid loth June, 1893. 
 
 1 RIB UTE 
 
 
 
 Tribute 
 
 
 Amount. 
 
 
 T. C. Q. 
 
 LBS. 
 
 
 
 
 
 . 
 
 d. 
 
 Tin i : 6 t 3 : 
 
 23 
 
 
 
 
 
 
 Price 52 per ton 
 
 
 
 
 
 
 
 
 
 
 11/4 
 
 46 
 
 
 c 
 
 
 
 
 
 
 
 
 
 
 
 9, 
 
 d. 
 
 
 
 
 Returning charges . 
 Subsist and dressing . 
 
 10 
 
 10 
 
 3 
 13 
 
 6 
 I 
 
 
 
 
 Materials and drawing . 
 
 4 
 
 4 
 
 9 
 
 
 
 
 Doctor, club, and barber 
 
 
 II 
 
 
 25 
 
 12 
 
 4 
 
 Balance 
 
 
 
 
 
 
 
 21 
 
 2 
 
 i 
 
 The pay-ticket shows that John Jones and his partners, a 
 gang of three men, raised a certain quantity of crude tin ore 
 (tinstujf) which, according to assays, contained i ton 6 cwt. 
 3 qrs. 23 Ibs. of clean tin ore (black tin). The value of this 
 quantity, at $2 per ton, is 70 is. Sd. The pay -ticket also 
 states that the tribute was 135. \d. in the pound, or, in other 
 words, two-thirds of the value. The gross total credited to 
 the gang was therefore ^46 145. $d. Against this come the 
 returning charges, subsist, dressing, drawing, and sampling, as 
 follows : 
 
 Returning charges . . . 
 
 Subsist 
 
 Dressing 
 
 Materials 
 
 Drawing and sampling . 
 
 Doctor, 55., Club, 45. 6d., Barber, is. 6d. 
 
 
 
 io 3 
 
 8 io 
 
 2 3 
 
 2 10 
 
 I I 4 
 
 O II 
 
 25 12 4 
 
 These deductions require a word of explanation. The return- 
 ing charges represent the cost of treating the "stun " from the 
 time it goes to the stamps until the dressed tin ore (black tin) 
 
PRINCIPLES OF EMPLOYMENT. 643 
 
 is fit for the smelter. The amount charged varies slightly in 
 different mines.* " Subsist " is another name for an advance, or 
 money paid on account, during the running of the contract, which 
 in this case lasted eight weeks. The term " dressing " as used in 
 these accounts is not very happily chosen, because the returning 
 charges represent all the cost of stamping and washing. The 
 " dressing " referred to in the pay-bill is the preparation of the 
 "tinstuff" for the stamps by "ragging," " spalling," &c. The 
 charge varies from ^d. to 6d. per ton, according to the hardness 
 of the veinstuff. In this case the books of the company showed 
 that 96 tons 6 cwt i qr. of tinstuff had been dressed. The 
 " materials " included candles, powder, fuse, dynamite, pick hilts, 
 detonators, a shovel, clay for the candles, and the smith's cost 
 for sharpening drills and picks. 
 
 " Drawing " is the Cornish term for winding, and is charged 
 at the rate of $d. per ton. The "sampling " refers to the assays of 
 the tin ore made upon the vanning shovel by the mine agent ; 
 they are charged at the rate of is. each, and it is upon the 
 results of these assays that the mine-owner ascertained that the 
 96 tons 6 cwt. i qr. of " tinstuff" contained i ton 6 cwt. 3 qr. 23 Ib. 
 of " black tin." One of the three men being a bachelor, paid only 
 6d. per month for the doctor, instead of the usual is. of the 
 married man, whose wife and family are likewise entitled to 
 receive medical attendance. 
 
 In former days the " tribute," or proportion of the value re- 
 tained by the workmen, was publicly fixed by Dutch auction on 
 the " setting " day. The miners assembled outside the mine 
 office (counting-house), and the manager, after reading out the 
 nature of the " pitch," or working place, asked for bids ; the 
 lowest bidder received the contract. If a certain place seemed 
 likely to be profitable, there was frequently much competition 
 among the men in order to get the "pitch." Nowadays the 
 agreements are often made privately. It is evident that the 
 richer the lode, the smaller will be the proportion of the value 
 necessary for giving the men a fair return for their labour ; in 
 other words, the tribute will decrease as the lode improves. 
 
 This system of working has many advantages, which have 
 rendered it popular with men and masters in Cornwall and else- 
 where. The man's pay does not depend solely upon his muscular 
 exertion, but also upon his judgment. lie exercises his wits, he 
 
 * Common rates are : 
 
 . a. 
 
 On tinstuff producing i^ % (or less) of " black tin," 2 o per ton. 
 i|% to 2^% 30 
 
 24% 3S% 
 
 5 
 
 5 
 
 I 74 
 or above 
 
 3 6 
 
 4 o 
 
 5 o 
 7 o 
 
 10 o 
 
644 ORE AND STONE-MINING. 
 
 observes the nature of the ground, and notices what conditions 
 are most favourable for ore-bearing, such as colour and texture 
 of the surrounding rock ; what signs are the forerunners of richness 
 or poverty of the lode, such as intersections with "droppers" 
 or " feeders," joints in certain directions the appearance of asso- 
 ciated minerals. Guided by slight indications of this kind, which 
 would pass unnoticed by the inexperienced, he is ready to back 
 his favourable opinion of a certain working place (pitch} by 
 agreeing to work it at a price (tribute), which would seem quite 
 inadequate if one judged by the actual ore in sight at the time 
 of making the agreement. If he is correct in his inference, he 
 may make a large sum of money, and receive, for instance, one 
 fourth of ,200, instead of one-fourth of ^50, which seemed 
 probable from the original appearance of the ground. 
 
 This constant study of the geological features of the working 
 places and the calculations concerning the probable expenditure 
 for explosives and other materials, educate the miner, make him 
 brighter, shrewder, and more self-reliant, and so raise him 
 mentally. 
 
 The advantages of this training are also felt by the mining 
 company; they have in the mine a body of expert detectives 
 constantly on the watch for clues to lead them to hidden ore- 
 bodies which might otherwise go undiscovered, and while the 
 tributer is at work in any given " pitch," the mine-owner feels 
 little fear of ore being thrown away in. the rubbish, or of "waste" 
 being unnecessarily sent to the surface. As the interests of the 
 employer and the employed are in these respects identical, the 
 former knows that little or no supervision is required on 
 his part to prevent loss from either of the two causes just 
 mentioned. The tributer is therefore left much more to himself 
 than the man employed upon tutwork. Lastly, it may be 
 pointed out that so long as the profit made out of each bargain 
 is sufficient to pay its proportion of the general expenses of 
 pumping, ventilating, and management, the mining company 
 cannot lose by employing tributers. It is not to be wondered 
 that with these advantages the tribute system should be vaunted 
 to the skies by many mining engineers. 
 
 The other side of the picture must not be forgotten. In the 
 first place, the system is apt to promote duplicity among the men. 
 They are constantly endeavouring to outwit the agent by fair 
 means or foul, and will candidly confess that " the whole art of 
 mining is fooling the captain." The latter has often been a 
 tributer himself, and is fully alive to all the tricks which the 
 men are likely to practise upon him, such as conceal: ng any 
 indication of an approaching improvement, in order to get better 
 terms at the next " setting." This is not all ; it may happen that 
 two " pitches " not very far from one another asre being worked 
 at very different tributes, one bargain being rich and the other 
 
PRINCIPLES OF EMPLOYMENT. 645 
 
 poor. One gang may be getting two-thirds of the value of the 
 ore they raise, the others only one-tenth ; the men with the low 
 tribute, that is to say, jhe men in whose working place the ore 
 is abundant, are often ready enough for a consideration to part 
 with some of their stock to their neighbouis, who transfer it 
 secretly to the " pile " which they are sending up to the surface, 
 carrying it perhaps from one working place to the other in an 
 improvised sack made out of a pair of trousers. The result is 
 that the squad with the high tribute are paid at a far better rate 
 for some of their ore, than the trouble of getting it warranted. 
 When the rates of tribute vary between narrow limits the case is 
 different. For instance, the manager of a zinc mine was lately 
 paying 405. per ton for blende as the highest tribute and 305. as 
 the lowest, which, with the ore selling at ^5 per ton, corresponded 
 to Ss. and 65. in the pound respectively ; there was therefore little 
 or no temptation to transfer ore from one " pitch " to another, 
 and so defraud the company. 
 
 The training in trickery which is inherent to this system may 
 have its effect later on, when the tributer is promoted to a higher 
 position ; from having been taught to consider that cheating 
 the captain is perfectly fair and legitimate, he may be ready to 
 conclude that " the whole art of mining is fooling the public." 
 And blunting of the moral sense of the men is an undoubted 
 evil. 
 
 Payment by tribute involves the necessity of ascertaining the 
 value of each gang's raisings separately. In the case of tin ore 
 the percentage of cassiterite is learnt by washing a sample upon 
 the vanning shovel, and from the result of this assay the total 
 amount is easily reckoned ; but with lead and zinc each parcel is 
 dressed by itself, and the final lots of clean galena or clean blende 
 are weighed separately, before being mixed and made into heaps 
 for sale to the smelter. This multiplication of small operations, 
 cleanings-up, and weighings, naturally makes the cost of dressing 
 higher than it would be if all the ore were treated alike, without 
 regard to the persons who had raised it. 
 
 Another objection to the tribute system is that the lessened 
 amount of supervision for commercial purposes may tend to a 
 lessened amount of supervision for purposes of security ; the 
 working place is not visited so often by the agent, and he has fewer 
 opportunities of pointing out to the men possible dangers from 
 want of timbering or other sources. The men sometimes court this 
 lack of supervision by making access to their " pitch " difficult, or, 
 at all events, troublesome. Lastly, there is an element of gambling 
 involved in the tribute system, which it is scarcely advisable to 
 cultivate. The tributer is a speculator, who hopes by a lucky hit, 
 as comrades have done before, to make a lot of money in a 
 short time. Where one succeeds in so doing, how many fail ? 
 According to the report of Lord Kinnaird's Commission in 
 
646 ORE AND STONE-MINING. 
 
 1864,* the tutworker at that time was better housed than the 
 tributer ; the moral of this is that, on the whole, it is better for 
 the working miner to be in receipt of fairly constant regular 
 wages than to trust to the chance of occasional runs of luck. 
 
 The advantages accruing to a mine from the tribute system are 
 far less marked when there is a lode of pretty even character, than 
 when the deposit is fitful and uncertain in its nature. This 
 explains, to some extent, why the tribute sj'stem occupies a less 
 important place in Cornwall now than it did in the first half of 
 this century. Cornish mines at the present day are mainly 
 dependent upon tin lodes, in which the cassiterite is finely dis- 
 seminated through a hard close-grained rock. The consequence 
 is that it is impossible to do much picking underground, or indeed 
 at the surface ; the whole of the stuff raised from the stopes has 
 to be sent to the stamps. For deposits of this kind it is more 
 advantageous to employ the tutworker, who excavates the ground 
 at so much per fathom, than the tributer. Fifty years ago things 
 were different ; copper was then the mainstay of Cornwall, and 
 the chief ore was chalcopyrite. While cassiterite is a mineral 
 well adapted for dressing by water, chalcopyrite is not ; it crumbles 
 to dust very easily, and the fine particles are liable to be washed 
 away with the refuse. A large amount of hand-picking was 
 required, in order to save as much of the ore as possible from 
 treatment in water. The care of the tributer in the stopes of 
 copper mines was a matter of vital importance in the old days, 
 and his services were really valuable. 
 
 Where an old mine is re-worked after a period of abandonment, 
 the tribute system often does good service, especially if the object 
 is to recover some mineral considered worthless in former times, 
 or when branches of ore exist in the sides, after the main part of 
 the vein has been removed. 
 
 In a like manner it proved a valuable remedy f in the Eureka 
 district for evils which had resulted from the plan of working 
 the ore by day labourers. The ore occurs in bodies of irregular 
 shape and size ; men working by the day had not been careful to 
 get out as much ore as they might have done, and others were 
 induced by the tribute system to extract the portions remaining 
 v behind, which would otherwise have been lost altogether. Besides 
 which it was known that small ore-bodies had been passed over as 
 too poor or too insignificant to be worth removing in the ordinary 
 way, but which were quite good enough to afford a scope for the 
 talents of a man who had a direct interest in the ore he got out. 
 In 1881 the men received $2*50 for all ore assaying $30 
 
 * Report of the Commissioners appointed to Inquire into tie Condition of 
 all Mines in Great Britain to which the Provisions of the Act 23 tfe 24 Viet. 
 c. 1 51 do not apply. 
 
 t Curtis, ' The Silver-lead Deposits of Eureka, Nevada," Man. U.S. GcoL 
 Survey, vol. vii., Washington, 1884, p. 151. 
 
PRINCIPLES OF EMPLOYMENT. 647 
 
 per ton, and 50 per cent, of all that it assayed above $30. Thus 
 an ore worth $65 per ton brought to the tributer $2^50 + 
 $17*50, or $20. In cases of this kind the services of the 
 tributer are often requisitioned with good results to the mine ; 
 that is to say, when the greater part of the ore has been extracted 
 by some other method of payment, and when more judgment and 
 care are required to ferret out and take away partly hidden 
 treasures distributed here and there in the workings. 
 
 Under the old Cornish system of tribute, the partners are all 
 working men, who are all employed in the particular " pitch " 
 assigned to them ; but in Colorado one meets with a modification 
 of the method, in which the actual miner avails himself of outside 
 aid, and may or may not employ labourers who have no interest 
 in the adventure. A party of miners who have confidence in the 
 future resources of some part of a mine, take it upon lease and 
 obtain the assistance of shopkeepers or others in the neighbour- 
 hood, in order to buy tools, explosives, and materials, and to 
 have means of living during the unproductive stage of the under- 
 taking. If the hopes of the miners are realised, the sleeping 
 partners receive a share of the profits ; if the speculation turns 
 out badly, the miners have had a bare subsistence, and the 
 petty capitalists lose their money. This system has the advantage 
 that it enables a certain amount of dead work to be combined 
 with the extraction of ore. Under the Cornish system working 
 men will not drive levels and sink shafts in unproductive ground ; 
 because, however high the tribute may be, they receive nothing so 
 long as they raise no ore, and they cannot afford, on their own 
 resources, to spend weeks and months in making the preliminary 
 openings, which may be required before some given block of 
 ground is made ready to yield up its . supposed riches. A 
 little outside capital tides the workers over their difficulty, and 
 gives them a chance of making money by the exercise of their 
 brains as well as by the expenditure of their muscular strength. 
 The question will be asked : How does the small capitalist guard 
 himself against the risk of having to provide for the living of 
 some lazy miners, who, hidden below ground, are merely making 
 a pretence of working ? In the first place, he may take a pre- 
 caution, often omitted by the large capitalist, of associating 
 himself only with men whom he knows and can trust, and 
 secondly, as he is frequently a bit of a miner himself, he visits 
 the mine from time to time, and watches the progress of the 
 work. 
 
 The mine-owner favours this system, and even becomes a 
 partner himself, because he gets some of his dead work done 
 without any risk to his pocket. In the case of mines drained by 
 adit-levels and swept through by natural draughts, as is commonly 
 the case in Colorado, the mine-owner is put to no cost whatever 
 for pumping or ventilation, and therefore he loses no money even if 
 
6 4 8 
 
 OEE AND STONE-MINING. 
 
 the "lease" turns out a failure, whereas he is bound to be a 
 gainer if any ore is met with. 
 
 The following are two actual examples which explain the 
 system very clearly : 
 
 COLORADO LEASE. 
 
 Profitable Lease to both Company and Lessee. Company or Owner 
 having f interest, and Lessee \ interest. 
 
 LEASE ACCOUNT. 
 
 Nov. 30. 
 Dec. 30. 
 
 To Lessee's wages . 
 , Other wages . 
 , Supplies, powder, &c. 
 , 151 ore sacks . 
 , Hoisting, training. ?cc. 
 , Blacksmithina: 
 , Hauling ore to mill 
 By Proceeds ot ore 
 To Koyalty . . 
 ,, Lessee's wages . . 
 
 
 
 Dr. 
 
 $ c. 
 72.00 
 407.00 
 19-25 
 30.20 
 
 99-55 
 12.40 
 26.70 
 
 1119.40 
 78.00 
 573 J o 
 
 Cr. 
 
 $ c. 
 
 2238.95 
 
 
 , Powder, fuse, &c. . 
 , 100 ore sacks . 
 , Hoisting, training. &c. 
 , Blacksmithing 
 , Hauling ore to mill 
 By Proceeds of ores . . . 
 
 
 
 27.05 
 
 20.00 
 
 17-25 
 36.00 
 
 3471-75 
 
 
 
 
 
 /JJ .) 
 
 
 Net profit on lease 
 
 4405.20 
 
 5710.70 
 
 $5710. 70 $5710.70 
 
 Lessee received : 
 
 Wages for his labour 
 J of profits 
 
 150.00 
 326.40 
 
 Company or owner received : 
 
 Royalty ........ 2855.25 
 
 2 of profits 979. 10 
 
 Cost of work exclusive of lessee's labour 
 Total 
 
 476.40 
 
 3834.35 
 1399-95 
 
 $5710.70 
 
PHINCIPLES OF EMPLOYMENT. 
 
 649 
 
 COLORADO LEASE. 
 
 Unprofitable Lease to Lessee. 
 
 I 
 
 Owner \ Interest, and Lessee 
 
 LEASE ACCOUNT. 
 
 Oct. 31. 
 
 Sept. 30. To Lessee's wages 
 Other wages . 
 Powder, fuse, &c. . 
 Hoisting and training 
 Hauling ore to mill 
 By Proceeds of ore 
 To Royalty . 
 Lessee's wages 
 Other wages . 
 Powder, fuse, &c. . 
 Hoisting and training 
 ,, Hauling ore to mill 
 100 ore sacks . 
 By Proceeds of ore 
 To Royalty . 
 Lessee's wages 
 Other wages . 
 Powder, fuse, &c. . 
 Hoisting and trainirg 
 Hauling ore to mill 
 By Proceeds of ore 
 To Royalty . 
 
 Nov. 30. 
 
 Loss on lea? e 
 
 Thus the lessee received : 
 
 His wages for working amounting to 
 Less half loss on lease 
 
 Leaving him for his work . . 
 
 The Company received : 
 
 Royalty amounting to ... 
 Less half loss on lease 
 
 Net profit by the Company 
 
 Dr. 
 
 $ c. 
 117.00 
 442.30 
 
 50-30 
 67.85 
 26.95 
 
 660.80 
 117.00 
 483.90 
 
 25-iS 
 66.95 
 16.65 
 17-35 
 
 535- 10 
 
 122.20 
 3I4- iO 
 
 44-5 
 
 67.80 
 
 9.20 
 
 661.30 
 3846.60 
 
 Or. 
 
 $ c. 
 
 1321.60 
 
 1070.20 
 
 1322.60 
 
 3714.40 
 132.20 
 
 3846.60 3846.60 
 
 356.20 
 66.10 
 
 290. 10 
 
 1857.20 
 66. i o 
 
 $1791.10 
 
 The men who are excavating slate rock (rock-men), and 
 those who are subdividing it into merchantable slates (quarry- 
 men), in the Festiniog district, are paid by a method which 
 in principle resembles the tribute system. The earnings of 
 the men depend upon the value of the stock of merchantable 
 slate which they obtain from their working place or " bargain." 
 At the end of the month the stock of each partnership is counted, 
 
650 ORE AND STONE-MINING. 
 
 and the men are credited with the value of their make according 
 to a fixed tariff. Thus, for instance, we may suppose that the 
 men had made fourteen hundred slates of the size 24" x 14", at 
 275. 6d. per thousand ; for this their account would be credited 
 with i 1 8s. 6d., and so on with each size. On looking down 
 an account, it will often be found that the men have made " best " 
 slates of twenty different merchantable sizes, to say nothing of 
 several kinds of " seconds." The total of these various items is a 
 first basis of the amount due to the partnership ; but as the 
 " rock " varies in quality in the different working places, owing to 
 the presence or absence of joints, the interference of quartz veins, 
 or alterations of texture, the result of a given amount of 
 labour must necessarily vary also. In good rock the men will 
 make a large quantity of " best " slates of large sizes; elsewhere, 
 though working equally hard and excavating quite as many cubic 
 feet, they will be able to make only slates of small sizes, or 
 " seconds " in the place of " bests." Tl e companies find the 
 simplest method of adjusting these differences is to pay a premium 
 or allowance, varying with the quality of the rock in each 
 " bargain," and determined at the " letting," i.e., at the time of 
 making the contract. A " bargain " may be let for a month or for 
 several months. The premium is called " poundage." 
 Thus to take an actual case : 
 
 s. d. 
 
 Value of the slate produced, at tariff prices . . 16 19 i 
 Poundage ics. 896 
 
 Total . . ^25 8 7 
 
 The " poundage " of los. means a premium of los. in the pound ; 
 for every pound's worth of slate at tariff prices, the workmen 
 receive an additional half-sovereign; in other words, the value 
 of the total make is reckoned at 50 per cent, more than the 
 tariff prices. If the bargain is a good one, the poundage will be 
 low ; if the rock deteriorates in quality, the poundage will have 
 to be raised at the next letting. 
 
 Another example will make this plainer : 
 
 s. d. 
 
 Value of the slates produced, at tariff prices . . 9 19 r 
 Poundage 32$. 6d 16 3 6 
 
 Total . . 26 2 7 
 
 These two amounts, ^25 85. yd. and 26 2s. yd., are the 
 gross earnings, in each case, of four men for a month, and are 
 subject to deductions for materials supplied. 
 
 In the former case the deductions were : explosives, 6s. 6cZ., 
 fuse, is., candles, 45., smith, 55. lid., or 175. $d. in all, leaving a 
 balance of .24 us. 2d. which was handed to the men. In this 
 
PRINCIPLES OF EMPLOYMENT. 
 
 651 
 
 bargain there were three partners, who employed a labourer, and 
 worked twenty-four days. The company leaves the division of 
 the money to the men themselves, but keeps an account so as to 
 know precisely what the earnings are. The recognised wages 
 of a labourer at Festiniog were 45. 2d. a day, so the labourer was 
 paid ^5, i.e., twenty-four times 43. 2d. There remained, there- 
 fore, a net balance of ;i9 us. 2d. to be divided among three 
 men. According to the time-book, these men worked 70 J days 
 between them, and therefore their average wages were 55. 6d. 
 per man per day. 
 
 In the other case the account stood thus : 
 
 
 
 
 
 
 8. 
 
 d. 
 
 
 
 
 26 
 
 2 
 
 
 
 
 
 ' 
 
 
 
 DEDUCTIONS. 
 
 & 
 
 *. j d. 
 
 
 
 
 Powder 
 
 Blasting gelatine . 
 Detonators . 
 Fuse . 
 Candles 
 
 
 i 
 
 14 ! 10 
 6 ' 6 
 I J 6 
 2 j 
 
 \ ! I 
 
 i 
 
 i 
 
 j 
 
 13 
 
 8 
 
 
 
 
 
 
 
 Net balance 
 
 - 
 
 . . 
 
 24 
 
 8 
 
 II 
 
 Here there were four partners and no labourer; they made 
 94 days between them, or at the rate of 55. 2cZ. per man per 
 day. In spite, therefore, of the very great difference in the rock, 
 the poundage was so fixed beforehand as to enable each set of 
 men to earn very nearly the same wage per day. 
 
 At Festiniog the partnership commonly consists of four per- 
 sons : two working below ground, and engaged in getting the slate- 
 rock, and two working above ground in the mills, engaged in 
 making the blocks into merchantable slates The reason for this 
 arrangement is the fact that the yield of slate from any given 
 block depends very largely on the skill of the dressers, and if the 
 splitting and making of the slates were confided to men paid by 
 the day, these would have no interest in doing their best with 
 the material delivered to them. Now the men working below 
 ground can rely upon their own partners to work up the blocks 
 into slates with the least possible loss ; the case is a totally 
 different one from dressing a metallic ore. Owing to the 
 nature of the substance which is being quarried, the payment by 
 a varying " poundage " is free from some of the objections which 
 
652 ORE AND STONE-MINING. 
 
 are inseparable from the " tribute " system at ore mines. At the 
 latter the change in the value of a lode may be so sudden, that a 
 single blast will convert a " pitch " originally " set " at a tribute 
 of two-thirds, into one which could be worked profitably by the 
 men at one-twentieth. If such a change takes place some time 
 before the end of the contract, the men raise far more ore than 
 was thought possible when the bargain was arranged, and make 
 what is known to Cornishmen as a " start "or " sturt," in other 
 words "a big haul." Cases are known in which a party of 
 tributers have earned as much as ^100 each in a month, instead 
 of the expected ^4 or ^5. The possibility of such good fortune 
 naturally encourages the miner to take the risks incident to work- 
 ing upon tribute, and at the same time prompts him to deceive 
 his superiors if he can. With slate, the " rockman " may be 
 favoured by unexpected joints, and he may be able to earn twice 
 as much as was expected when he entered into his contract, but 
 he does not get twenty times as much, nor is he liable to find his 
 " bargain " so suddenly become poor or absolutely worthless as 
 may happen with a copper lode in Cornwall. There are also 
 fewer opportunities of hiding coming improvements from the eyes 
 of the agents. The result is that there are fewer attempts at 
 concealment, and consequently there is less chance of the moral 
 feeling being blunted ; sudden great variations in the earnings are 
 rare, and the solution of the problem of payment by results seems 
 very satisfactory. 
 
 As a final instance of the payment of wages, may be mentioned 
 that of piecework combined with premiums for good conduct. 
 This system was introduced at the large stone quarries of 
 Quenast in Belgium * in order to make the men stick to their 
 work during the regular hours, and not absent themselves on the 
 pretext that, as they were paid by results, they could do as they 
 pleased. The company instituted a higher rate of wages and 
 prices applicable only to men who did not leave the quarry 
 during working hours without permission. The men soon dis- 
 covered that it was to their advantage to get the higher tariff, 
 the public-houses were less frequented, the average earnings 
 increased, and the company had more work done. 
 
 * ' Continental Notes," reporting communication by Urban to Brussels 
 Section of the Liege Engineers. Coll. Guard., vol. Ixiii. 1892, p. 844. 
 
653 
 
 CHAPTER XV. 
 LEGISLATION AFFECTING MINES AND QUARRIES. 
 
 Ownership Taxation Working regulations ; Metalliferous Mines Regula- 
 tions Acts, 1872, 1875, an d I 89i ; Coal Mines Regulation Act, ^87 ; 
 Alkali Acts Boiler Explosions Acts Brine Pumping (Compensation 
 for Subsidence) Act Elementary Education Acts Employe! s' 
 Liability Act Explosives Act ; Factory and Workshop Acts Quarry 
 Fencing Act Rivers Pollution Prevention Act Stannaries Act, 1887 
 Truck Acts. 
 
 TIIE object of this chapter is to call the student's attention to the 
 principal laws afiecting the working of mines and quarries in the 
 British Isles. 
 
 The subject may be taken under the following heads : 
 
 1. Ownership. 
 
 2. Taxation. 
 
 3. Working regu'ationa. 
 
 4. Sundry special statutes. 
 
 I. Ownership. In the United Kingdom the person owning 
 the surface is primd facie entitled to all the minerals under- 
 neath, excepting in the case of mines of gold and silver, which 
 belong to the Crown. The Crown, however, does not claim gold 
 and silver extracted from the ores of the baser metals. Thus we 
 find that the Crown receives a royalty for the gold extracted 
 from auriferous quartz raised upon private property in Wales, 
 but gets nothing whatever for the silver contained in argenti- 
 ferous galena. 
 
 The ownership of the minerals can be, and often is, severed 
 from that of the surface, the latter being sold whilst the mineral 
 rights are reserved by the original owner. Minerals lying under 
 the surface between high and low water mark are claimed by the 
 lord of the manor, while everything under the sea and beyond lew 
 water mark is the property of the Crown. 
 
 In the majority of cases in the British Isles,* the proprietor of 
 the minerals does not work them himself, but concedes the right 
 
 * Final Report of tie Royal Commission appointed to Inquire into the 
 subject of Mining Royalties. London, 1893. This Report contains much 
 information also about the Mining systems of the Colonies and foreign 
 countries. 
 
654 ORE AND STONE-MINING. 
 
 to another person in return for an annual rent and a royalty. 
 Usually a certain minimum rent is fixed, which has to be paid 
 even if no mineral is being raised, but this rent merges in the 
 royalties ; that is to say, the amount paid as royalty is put to the 
 credit of the rent, or, if sufficient, covers it entirely. 
 The royalty may be : 
 
 (a) A fixed sum per acre worked. 
 (6) A fixed snrn per ton raised. 
 
 (c) A fixed proportion of the value of the mineral raised. 
 
 (d) A varying proportion of the value of the mineral sold, regulated 
 
 by a sliding scale. 
 
 The first principle is more especially adopted in the case of 
 coal ; on the other hand, a fixed rate per ton is common in the 
 case of stratified ironstone. In the Cleveland district, the royalty 
 is 6d. per ton on an average, and the leases extend for 42 
 years. 
 
 Mineral veins are generally worked upon the third system ; 
 royalties vary from one-tenth downwards, though this amount is 
 quite exceptional. It is not uncommon for the lessee to pay one- 
 eighteenth or one- twenty- fourth as royalty, and if a mine is 
 struggling against low prices of metal, the "lord" is often 
 induced to abate his legal claims very considerably, or even to 
 agree to forego all payments until trade revives. The royalty is 
 calculated upon the ore made ready for the market. Thus, for 
 instance, in one of the reports of Dolcoath mine in Cornwall we 
 read : 
 
 By tin ore, 257 tons igcwt. I qr. fibs . ^"19,596 13 6 
 Deduct G-. L. Basset, Esq., dues i-2Oth. . 979 16 8 
 
 ;i8,6i6 16 10 
 
 Leases in Cornwall are usually granted for 21 years. The 
 lessor stipulates that a certain number of men shall be kept con- 
 stantly at work. Ground for tipping rubbish has to be paid for, 
 and sometimes at extravagant rates. When a lease is drawing to 
 a close, a new one is usually granted upon terms at least as 
 favourable as those of the old ones; but cases have arisen in 
 which the " lord " has required a heavy premium before he would 
 grant a new lease. 
 
 The haematite of the Carboniferous Limestone of Cumberland 
 and North Lancashire is usually leased upon a sliding scale, 
 which increases the proportion paid as royalty when the price of 
 ore goes up. Thus if iron ore is selling under 93. per ton the 
 lessor receives lod. per ton as royalty, i.e., exactly one-tenth if 
 the price is 8s. 4d. Supposing the value of the ore to rise to 143. 
 per ton, the lessee would have to pay 2s. or one-seventh. With 
 intermediate prices the fraction might be one-eighth or one- ninth. 
 The leases are for 21 years. 
 
LEGISLATION AFFECTING MINES, ETC. 655 
 
 Many centuries ago the Crown claimed the right to all 
 minerals, and, in order to promote mining, privileges were 
 granted to persons who would endeavour to discover and work 
 mines ; from these privileges and from old usages have resulted 
 special mining rights peculiar to certain districts. Those per- 
 taining to Derbyshire have now been definitely fixed by two 
 special Acts of Parliament, the High Peak Mining Customs and 
 Mineral Courts Act, 1851 (14 & 15 Viet. c. 94) and the Derby- 
 shire Mining Customs and Mineral Courts Act, 1852 (15 & 16 
 Viet. c. 43). Again, there are two special statutes (i & 2 Viet. c. 
 43 and 24 & 25 Viet. c. 40) which regulate the opening and 
 working of mines and quarries in the Forest of Dean, where the 
 " free miners " have certain peculiar rights. 
 
 These Acts are merely of local importance, but they are of 
 interest as preserving old customs. 
 
 2. Taxation. Mining companies have to bear their share of 
 Imperial taxes and local rates.* By " The Rating Act, 1874" 
 (37 & 38 Viet. c. 54) tin, lead, and copper mines are assessed on 
 the amount of dues payable, and in some districts a large pro- 
 portion of the rates may be paid by the mines, an arrangement 
 which is not unfair, if they are the cause of heavy burdens being 
 thrown upon the community. 
 
 3. Working Regulations. We now come to the third division 
 of this chapter, viz., the statutory regulations which are in force 
 for the safe working of mines. 
 
 Special legislation for promoting the safety and well-being of 
 the miner is a growth of the last half-century. I do not mean 
 by this that there were absolutely no regulations in days gone by ; 
 there were rules which had grown up in some places, from customs 
 and privileges so carefully preserved that they had become laws, 
 but these related mainly to the acquisition and preservation of 
 mining property, and only incidentally to the prevention of 
 accidents. 
 
 In order to make the state of our laws clear, and especially to 
 those who may be accustomed to Continental regulations, it is 
 necessary to point out once more that the sources from which we 
 obtain minerals are of three kinds : 
 
 a. Open works, that is to say workings open to the sky. 
 
 b. Mines, that is to say workings carried on underground by 
 artificial light. 
 
 c. Boreholes, or old flooded mines, from which brine is 
 pumped. 
 
 As was said in Chapter I., it is the nature of the excavation 
 and not the nature of the mineral, which settles, in this country, 
 whether a given working is a mine or not. Consequently it must 
 
 * Coal, Ironstone, and other Mines (Hating). Parliamentary Paper No. 
 405, Session 1890. Price 2^d. 
 
656 ORE AND STONE-MINING. 
 
 be understood that the purely mining Acts in no way affect open 
 workings, save such as may form part and parcel of a true mine. 
 The actual mining statutes now in force are as follows, in 
 chronological order : 
 
 The Metalliferous Mines Regulation Act, 1872 (35 & 36 Viet. 
 c. 77). 
 
 The Metalliferous Mines Regulation Act, 1875 (3$ & 39 "Viet. 
 
 c. 39)- 
 
 The Slate Mines (Gunpowder Act), 1882 (45 Viet. c. 3). 
 
 The Coal Mines Regulation Act, 1887 (50 & 51 Viet. c. 58). 
 
 The Metallifeious Mines (Isle of Man) Act, 1891 (54 & 55 
 Viet. c. 47). 
 
 The first of these Acts was passed after the report of the Royal 
 Commission appointed in 1 860 to inquire into the condition of mines 
 which were then not under inspection, and it was made to embrace 
 every mine to which the sister Act, the Coal Mines Act of 
 1872, did not apply. Therefore every mine in the kingdom is 
 under inspection : either it is subject to the provisions of the Coal 
 Mines Act, 1887, which has taken the place of the 1872 statute, 
 or it is under the Metalliferous Act of 1872. The former Act 
 applies to mines of coal, stratified ironstone, shale, and fire-clay, 
 and therefore the latter takes cognizance of everything else. The 
 titles of the two Acts are misleading. Three times as much iron 
 ore is obtained from mines under the Coal Act as from mines 
 under the Metalliferous Act, and the largest mine under the 
 latter does not produce metallic ores. Soon after the passing of 
 the Metalliferous Act, the owners of an underground slate quarry 
 in North Wales refused to have their workings treated as mines. 
 They asserted with some plausibility that the Statute was the 
 " Metalliferous Mines Act," and that their workings had invariably 
 been known as " quarries," and never as " mines." The matter 
 had to be brought before the Court of Queen's Bench, and there 
 it was speedily decided that, in spite of popular phraseology, the 
 Festiniog underground quarries were legally "mines," and, as 
 such, subject to inspection, quite as much as the Cornish tin mine, 
 the Cumberland iron mine, or the Derbyshire lead mine. 
 
 I will now proceed very briefly to pass in review the most 
 salient points of these two Acts of Parliament, beginning with the 
 simpler, and incidentally point out the slight modifications intro- 
 duced by the other three statutes mentioned in my list. 
 
 The Metalliferous Act is divided into three parts. 
 
 Part I. deals with employment of women, girls, and boys. No 
 females can work below ground, nor can any boy under 1 2 years 
 of age. Boys under 16 cannot be employed more than 54 hours 
 in any one week, or more than 10 hours in any one day. 
 
 The person in charge of machinery for raising and lowering 
 men must be a male of at least 18 years of age. 
 
LEGISLATION AFFECTING MINES, ETC. 657 
 
 Wages must not be paid in public- houses. 
 
 An Annual Return has to be sent every year to the Inspector 
 of Mines of the district, specifying the number of persons em- 
 ployed, and the output of mineral. Under the 1872 Act, the 
 mine-owner was not obliged to furnish this return for any given 
 year until ist August following. This delay in the despatch of 
 the return was manifestly absurd, for the statistics based upon 
 them could not be published until they had lost much of their 
 interest; the fault in the 1872 Act was corrected by the short 
 amending Act of 1875, which changed the date from the ist 
 August to the ist February every year. 
 
 The owner* or agent has to send to the Inspector of Mines of 
 the district notice of every fatal accident, of every accident causing 
 serious personal injury,and of every accident, no matter how trifling, 
 causing personal injury by reason of any explosion of gas, powder, 
 or of any steam-boiler. The word " serious " gave a little trouble 
 at first. Some agents were inclined to interpret it as meaning 
 " likely to prove fatal," and did not report broken arms and legs, 
 because there was every reason to suppose that the man would 
 recover. Nowadays, when the period of disablement is likely to 
 exceed a week or ten days, the accident is usually notified. 
 
 Notice of opening, discontinuance, recommencement or aban- 
 donment, has to be sent within two months. 
 
 The section which follows (sec. 13) is one which was very much 
 wanted, and which is still often called into requisition. It is the 
 portion of the Act which provides for the secure fencing of shafts 
 and side entrances of mines which are no longer at work. In 
 working mineral veins, the " old men " sank their shafts as close 
 to one another as they still do in mining ozokerite at Boryslaw, 
 and the surface of open and uninclosed land was often riddled 
 with holes like a sieve. If the tops of these shafts were in hard 
 rock or were lined with stone, they remained open, and were a 
 source of danger by day and by night, for many were close to 
 roads or foot-paths, and, when partly or entirely concealed by 
 brambles or bushes, they formed veritable man-traps. In other 
 cases the timber lining at the top had decayed and the ground 
 had run in, leaving a huge yawning crater, 10 or 20 yards across, 
 leading to a pit hundreds of feet deep. It is true that a visible 
 danger of this kind was known to the inhabitants of the district 
 and could be avoided by daylight, but strangers were exposed 
 to a considerable amount of peril. Five and twenty years ago the 
 state of some of the open commons in Cornwall and Flintshire was 
 simply scandalous ; and even now there are often good grounds 
 for complaint on the part of the public, as fences become defective 
 from having been constructed originally in too flimsy a manner, or 
 
 * The word "owner "has a special interpretation under the statute 
 and refers to the lessee or company working the mine, and not to the pro- 
 prietor of the soil or mineral rights. 
 
 2 T 
 
658 ORE AND STONE-MINING. 
 
 from the mischievous pranks of passers-by. Occasionally, too, an un- 
 known shaft comes to light from the decay of the platform of 
 planks which had been put over it and covered with earth when 
 the mine was abandoned. If treated in this way the top soon 
 becomes grown over with grass, and recollection of the shaft 
 gradually fades away. These timber " sollars," as they are called, 
 should never be put in unless there is also a secure fence. Many 
 narrow escapes have occurred in Cornwall from the giving way 
 of such coverings, where the presence of a shaft was quite un- 
 suspected. 
 
 Abandoned mines are not only a source of danger to the 
 general public by creating pitfalls, but they may also threaten 
 the workers in the vicinity by holding accumulations of water 
 or gas, liable to be tapped unexpectedly if the boundaries 
 of the old workings are not known. To guard against such 
 possibilities, the owner, who is bound to keep an accurate plan 
 and section of his mine during the progress of the workings, 
 is further obliged to deliver up a copy when he abandons them ; 
 these plans are filed at the Home Office, and can be consulted if 
 necessity arises. They serve also to show new-comers, who pro- 
 pose to reopen an old mine, what work has been done by their 
 predecessors. 
 
 The next section of the Act relates to the Inspectors of Mines, 
 who are appointed by the Secretary of State for the Home 
 Department. The Inspector may not practise as a mining 
 engineer, manager, agent or valuer of mines. In addition to 
 enforcing the provisions of the Act, the Inspector has the right to 
 complain of any thing or practice in the mine which is 
 dangerous, or defective, or, in his opinion, threatens or tends to 
 the bodily injury of the persons employed. In order to prevent 
 an unreasonable Inspector from pushing matters too far, the 
 owner and agent are duly safeguarded. They can object to the 
 Inspector's notice about these alleged defects and have the matter 
 referred to arbitration. 
 
 Each Inspector has to make an Annual Report, which is laid 
 before Parliament and afterwards published as a Blue-book. 
 
 This is a convenient place for explaining that the United 
 Kingdom is divided, for the purposes of inspection, into thirteen 
 districts, each under a Chief Inspector, who, as a rule, has from 
 one to three assistants. 
 
 The following separate publications are issued annually by the 
 Home Office : 
 
 Report by each Inspector for his district 
 Statistical Summaries showing the number of persons em- 
 ployed, the deaths from accidents, and the quantity of 
 mineral raised, together with the corresponding figures 
 for previous years. 
 List of all the Mines in the United Kingdom. 
 
LEGISLATION AFFECTING MINES, ETC. 659 
 
 List of Record Plans deposited at the Home Office. 
 Mineral Statistics of the United Kingdom. 
 
 The last section of Part I. of the Act refers to the duties of 
 the coroner, who cannot conclude an inquest upon the body of a 
 person killed by a mine accident, unless due notice has been given 
 to the Inspector of the district. As a rule the Inspector attends 
 the inquest, and can be of much assistance to the coroner in 
 eliciting evidence, for he will have seen the place where the 
 accident took place, and will know whether it is likely that it 
 has been caused by pure ill-luck or through neglect of proper 
 precautions. 
 
 Part II. of the Act contains the General Rules, and sets forth 
 the mode of establishing Special Rules. 
 
 The General Rules are a series of nineteen regulations which 
 have to be observed in every mine. 
 
 Ventilation. Rule i relates to ventilation. It prescribes that an 
 adequate amount of ventilation shall be constantly produced, so that 
 the various parts of the mine shall be in a fit state for working 
 and passing therein. No standard of ventilation is laid down, 
 nothing is said about the number of cubic feet per minute that 
 have to be supplied, nor as to any given percentage of noxious 
 gas rendering the ventilation " inadequate." 
 
 Explosives and Blasting. Rule 2 defines how explosives are to 
 be taken into the mine, and lays down the precautions which 
 have to be observed while they are being used. Storage under- 
 ground is forbidden ; the mine should have a proper magazine 
 above ground, from which explosives should be dealt out daily to 
 the miners in small lots as required. In order to save trouble in 
 keeping the account of the small daily doles, a subsidiary magazine 
 is sometimes kept up, in which each gang of men has a locker. A 
 proper attendant then serves out explosives every day from the 
 lockers, without weighing the quantities. 
 
 The explosives must be taken into the mine in a case or 
 canister which must not contain more than four pounds. 
 
 Iron and steel needles or prickers are prohibited, but the 
 Secretary of State has power to exempt mines from this 
 restriction if he thinks fit. Exemptions of this kind have been 
 granted in the case of the salt mines of Cheshire. Iron and steel 
 tamping bars may not be used for ramming in the wadding or 
 the first part of the tamping. It is lastly illegal to pick out or 
 bore out the tamping of a charge of powder which has missed 
 fire. 
 
 By the Slate Mines (Gunpowder) Act, 1882, the Secretary of 
 State has power to relax the restrictions concerning explosives. 
 This Act was passed for the convenience of workers in slate mines, 
 who occasionally have to fire large blasts of 8, 10 or 12 pounds 
 of powder, in order to sever a large block of slate which has not 
 been completely released by the original shot. The powder is 
 
66o ORE AND STONE-MINING. 
 
 sometimes required on the spur of the moment, as water might 
 fill up the crack by the time the man had made the journey to 
 and from the surface for a supply. Many agents of slate mines 
 are of opinion that it is safer to carry powder into the mine in 
 the 25-pound kegs coming direct from the manufacturer than in 
 the ordinary 4-pound canisters. Where exemptions have been 
 granted under this Act, the dangers incident to storing these 
 kegs of powder and opening them by candle-light are reduced as 
 far as possible by stringent special rules. 
 
 Inclined Planes and Horse Roads. Rules 3, 4, and 5 relate to 
 signals and refuge places on inclined planes or horse roads. 
 
 Shafts. In Rules 6, 7, and 8 are very important regulations 
 concerning shafts. The sides have to be made secure, and the top 
 of the shaft and all entrances to it have to be fenced. 
 
 Descent and Ascent. The next seven rules relate to the descent 
 into mines and ascent therefrom, whether by ladders or machinery. 
 
 If ladders are used, the ladderway must be partitioned off from 
 the winding compartment. The object of such a partition is not 
 only to prevent men from falling into the winding compartment, 
 but also to protect them from stones, which might drop from 
 the bucket or skip during hoisting operations. Vertical and 
 overhanging ladders are forbidden, and substantial platforms 
 are required at intervals riot exceeding 20 yards. The rule 
 also says that " a ladder shall be inclined at the most convenient 
 angle which the space in which the ladder is fixed admits." 
 The wording is unfortunate, because it sometimes fails to secure 
 a proper inclination for ladders; there is nothing to prevent 
 a person from sinking too small a shaft, and then alleging 
 want of space as an excuse, when a complaint is made to him 
 about the great steepness of his ladders. The Belgian law is 
 worded better, for it says that no ladder shall be inclined at an 
 angle of less than 10 from the vertical. 
 
 The only statutory enactment about man-engines is that they 
 shall be partitioned off from the winding compartment of the 
 shaft. 
 
 We now come to ascent and descent by winding machinery. 
 Guides and signalling apparatus are required as soon as a shaft 
 exceeds 50 yards in depth, and a cover overhead is obligatory 
 unless ail exemption has been granted by the inspector. A single 
 linked chain is forbidden ; the winding drum must be provided 
 with flanges to prevent the rope from slipping off; there must be 
 an adequate brake, and an indicator to show the position of the 
 load in the shaft. 
 
 Dressing-room. It was quite right on the part of the Legislature 
 to make provision by Rule 16 for a changing house, or " dry," 
 enabling the men to change their clothes in comfort, and have 
 easy means of drying their wet underground suits ready for the 
 next day ; but the wording might have been a little more elastic. 
 
LEGISLATION AFFECTING MINES, ETC. 661 
 
 As the law stands, a mine need not have a " dry " if fewer than 
 thirteen persons are employed below ground ; and yet one meets 
 with wet sinking shafts employing only ten or a dozen men, 
 where some accommodation is desirable, and with large mines 
 which are so dry that a changing house, as generally understood, 
 is superfluous. 
 
 Fencing Machinery. llule 17 prescribes that all dangerous 
 machinery must be fenced. 
 
 Steam Boilers. The only statutory regulations concerning 
 steam boilers are found in Rule 1 8, which says that every such 
 boiler must be provided with three fittings, viz., a steam gauge, 
 a water gauge, and a safety valve. 
 
 Wilful Damage. The last Rule, No. 19, forbids the wilful 
 damage of, or removal of fences or appliances provided for the 
 safety of the men. 
 
 In order to make the owner and agent responsible for the 
 proper carrying out of these essential regulations, this section of 
 the Act concludes with a very strict clause. As a rule, in this 
 country, a man is assumed to be innocent until he is proved 
 guilty. In mining, it is different ; if a contravention of the Act 
 by any person whomsoever, for instance, a workman, is proved, 
 the owner and the agent are each made guilty of an offence and 
 are liable to punishment, unless they can prove that they had 
 taken all reasonable means to prevent the contravention by 
 publishing, and to the best of their power, enforcing the rules. 
 The Legislature has therefore taken strong means in order to 
 render the miner's calling safe. On the other hand, the owner 
 and agent are thoroughly safeguarded by a clause, which governs 
 the whole of the section, and says that the rules are to be 
 observed " so far as may be reasonably practicable." 
 
 Special Rules may be regarded as by-laws framed to suit 
 the conditions of any particular district or mineral deposit; 
 when once established with the formalities prescribed by law, 
 they have all the power of the statute itself. They are a very 
 useful institution, and as there are simple means of modifying 
 them, changes can be introduced from time to time, without 
 having to set in motion the ponderous machinery required to 
 alter an Act of Parliament. At mines under the Metalliferous 
 Act, special rules are not compulsory as they are under the Coal 
 Mines Act ; but the Secretary of State can propose any rules he 
 thinks fit to the owner of the mine, who may object and have the 
 matter decided by arbitration. 
 
 An Abstract of the Act, and a copy of the Special Rules (if any) 
 have to be posted up in a conspicuous place at the mine, where 
 they can be conveniently read by the workpeople. The name 
 and address of the Inspector of the district have to be appended, 
 so that every one may know to whom to apply in case of need. 
 
 Part III. deals with penalties for offences and the technicalities 
 
662 ORE AND STONE-MINING. 
 
 relating to legal proceedings. The penalties to which a person 
 is liable for a breach of the Act are a maximum of 20 if he is 
 an owner or agent, and a maximum of 2 if he is any other 
 person ; the fine may be increased by i a day so long as the 
 offence continues, if the offender has received notice in writing 
 from the Inspector. For wilful neglect, endangering life and limb, 
 a person may be sentenced to imprisonment, with or without 
 hard labour, for a period not exceeding three months. 
 
 The owner and agent cannot be prosecuted except by an 
 Inspector, or with the consent in writing of the Secretary of 
 State. The workman can be prosecuted by his master ; and 
 proceedings against the men become necessary when the master 
 finds that mere words fail to secure strict obedience to regula- 
 tions, which is imperative in a dangerous occupation like mining. 
 
 Strange to say, the clause which prevents interested magis- 
 trates from sitting in cases under the Coal Mines Act, is omitted 
 altogether in the Metalliferous Act. 
 
 Where a penalty amounts to or exceeds half the maximum, the 
 person convicted may appeal to a higher court. 
 
 The last Mining Act, that of 1891. was passed in order to 
 correct a curious omission in the old statute of 1872, which failed 
 to define the Court of Summary Jurisdiction in the Isle of Man 
 before which proceedings could be taken. 
 
 Having thus briefly explained the statute by which the working 
 of many ore and stone mines is regulated, we must now pass on 
 to the Coal Mines Regulation Act, 1887, which governs mines of 
 stratified ironstone, shale and fireclay, as well as collieries. Com- 
 pared with coal, it is true that these minerals are of minor import- 
 ance; but as their total output amounts to more than 12,000,000 
 tons annually, of which 7,000,000 tons are ironstone, it is 
 evident that even the ore miner should be acquainted with the 
 requirements of this statute. 
 
 It presents many points of resemblance with the Metalliferous 
 Mines Regulation Act, but it is far more elaborate in its details ; 
 to save repetition it will be best to dwell more especially upon the 
 points in which it differs from the Act which we have just been 
 discussing. 
 
 In Part I. the principal new features are : 
 
 Hours of Labour. Regulation of the hours of labour of boys 
 and females employed .above ground. 
 
 Check Weigher. If the majority of the men wish it, they may 
 appoint a check weigher to see that the weighing is done correctly, 
 and that deductions are made fairly. 
 
 Prohibition of Single Shafts. The object is to provide two 
 means of egress in case of accident ; certain mines may be 
 exempted from this provision. 
 
 Division of Mine into Parts. Under certain circumstances 
 each part must be treated as a separate mine. 
 
LEGISLATION AFFECTING MINES, ETC. 663 
 
 Certificated Managers. This is one striking difference between 
 the Metalliferous Act and the Coal Act. Under the former a per- 
 son without any pretensions to professional qualifications may be 
 placed in charge of a mine ; under the latter every mine employ- 
 ing more than thirty persons below ground must have a certificated 
 manager. In order to obtain a certificate the candidate must 
 have had practical experience in a mine for at least five years, and 
 must then pass an examination. For the purpose of granting 
 certificates, boards for examination have been appointed in each 
 of the twelve districts into which the kingdom is divided for the 
 purposes of the Coal Mines Act. Unfortunately the statute makes 
 no provision for securing uniformity in the examinations. Even 
 the limits of age are not the same ; but, nevertheless, a certifi- 
 cate when once obtained, is good for any part of the kingdom. 
 
 Returns. The Annual Return which has to be furnished under 
 the Coal Mines Act not only gives the output of the mine and 
 the number of persons employed, but also supplies details con- 
 cerning the mode of ventilation ; the part relating to the quantity 
 of mineral wrought cannot be published, save by consent of the 
 person making it, or of the owner of the mine. This restriction 
 prevents the publication of such details as appear in the " Mineral 
 Statistics" in the case of mines under the Metalliferous Act. 
 
 Inquests. At coroners' inquests, a relative of the person killed, 
 the owner, agent, or manager of the mine in which the accident 
 happened, and any person appointed by the order in writing of 
 the majority of the workmen employed in the mine may attend 
 and examine witnesses. No such power is conceded under the 
 Metalliferous Act. 
 
 Part II., as in the other Act, contains the General Rules, and 
 regulates the establishment of Special Rules, which are compul- 
 sory instead of being voluntary. 
 
 The General Rules are 38 in number, or twice as numerous as 
 those in the sister Act. They may be passed in review very briefly 
 as follows : 
 
 Ventilation (i, 2, 3). Amount of ventilation to be ndequate ; 
 quantity of air to be measured monthly ; special airway to carry 
 the return current clear of the ventilating furnace ; ventilating 
 machines to be placed where they will not be injured by explo- 
 sions. 
 
 Inspections by Officials (4, 5). The working place has to be 
 inspected before men begin their work, and during the progress 
 of their work. Machinery must be inspected daily and shafts 
 weekly. 
 
 Fencing (6). Dangerous places must be fenced off. 
 
 Withdrawal of Men (7). Men must be withdrawn from 
 dangerous places. 
 
 Safety-Lamps (8, 9, 10, n). Use, construction, and examina- 
 tion of safety- lamps. Situation of lamp stations. 
 
664 ORE AND STONE-MINING. 
 
 Explosives (12). Prohibition of iron and steel tools for charging 
 holes, and special precautions for blasting in mines where tire- 
 damp has been noticed, or which are dry and dusty. 
 
 Advance Boreholes (13). These are made compulsory when 
 approaching water. 
 
 Signalling and Man- Holes for Travelling Roads (14, 15, 16). 
 
 Very like the rules in the Metalliferous Act. 
 
 Dimensions of Travelling Roads (17). Here we find that the 
 comfort of animals is not forgotten, for roads must be big enough 
 to allow the horses or ponies to pass along without rubbing. 
 
 Fencing of Shafts (18, 19). Very like the rules in the Metalli- 
 ferous Act. 
 
 Securing of Shafts (20). Identical with the rule in the Metalli- 
 ferous Act. 
 
 Securing of Travelling Roads (21). This very useful rule, 
 though contained in the Coal Mines Act of 1872, was not incor- 
 porated with the Metalliferous Act. 
 
 Timber (22). Props have to be provided at a convenient place 
 in the mine. 
 
 Descent and Ascent (23 to 30). In addition to the regulations 
 found in the Metalliferous Act, there is a rule preventing a speed 
 of more than three miles an hour after the cage has reached a 
 certain point in the shaft, when the winding apparatus is not pro- 
 vided with some automatic contrivance for preventing overwind- 
 ing. Men may use the downcast shaft for descent and ascent 
 if they wish to do so. No mention is made of ladders or man- 
 engines, which are not in use at mines under the Coal Mines Act. 
 
 Fencing Machinery (31). Identical with the Rule in the 
 Metalliferous Act. 
 
 Fittings for Steam Boilers (32). Very like the Rule in the 
 Metalliferous Act. 
 
 Barometer and Thermometer (33). These have to be placed in 
 a conspicuous position at the mine. 
 
 Ambulances (34). As suffering may be mitigated or life saved 
 by having proper appliances at hand for relieving and moving 
 injured men, the statute requires that stretchers, splints, and 
 bandages shall be kept ready for immediate use. 
 
 Wilful Damage to Fences, or Appliances for Safety (35). Very 
 like the rule in the Metalliferous Act. 
 
 Observance of Directions (36). M a n are bound to obey direc- 
 tions with respect to working, given with a view to comply with 
 the Act or Special Rules. 
 
 Books recording Results of Inspections (37). These have to be 
 kept at the office of the mine. 
 
 Periodical Inspection on Behalf of Workmen (38). The men 
 may appoint two practical working miners to inspect the mine, at 
 their own cost, once a month. The result of the inspection has 
 to be recorded in a book, and if the report states the existence or 
 
LEGISLATION AFFECTING MINES, ETC. 665 
 
 apprehended existence of any danger, the inspector has to be 
 informed of it. 
 
 Experienced Workmen (39). Men are not allowed to work alone 
 in getting coal or ironstone at the face of the workings unless 
 they have had two years' experience in or about the face of the 
 workings of a mine. 
 
 Part III. relates mainly to legal proceedings, and the only 
 special point to which attention need be called is the section which 
 prohibits persons interested in mines, or their near relations, from 
 sitting on the Bench and adjudicating upon breaches of the Act. 
 
 4. Sundry Special Statutes. It might be thought that 
 statutes framed for regulating mines would contain all that the 
 law requires for their safe and proper working ; but such is not 
 the case in this country. Miners and workers of open pits are 
 often affected by one or more of the following Acts of Parliament, 
 which are arranged in alphabetical order : 
 
 Alkali, &c., Works Regulation Acts, 1881 and 1892 (44 & 45 
 
 Viet. c. 37, and 55 and 56 Viet. c. 30). 
 Boiler Explosions Acts, 1882 and 1890 (45 and 46 Viet. c. 22, 
 
 and 53 and 54 Viet. c. 35). 
 Brine Pumping (Compensation for Subsidence) Act, 1891 (54 
 
 and 55 Viet. c. 40). 
 Elementary Education Acts, 1870 to 1891 (33 and 34 Viet. 
 
 c. 75 ; 38 and 39 Viet. c. 79, and 43 and 44 Viet. c. 23 ; 
 
 53 and 54 Viet. c. 22 ; 54 and 55 Viet. c. 56). 
 Employers' Liability Act, 1880 (43 and 44 Viet. c. 42). 
 Explosives Act, 1875 (3& Viet. c. 17). 
 Factory and Workshops Acts, 1878 and 1891 (41 and 42 Viet. 
 
 c. 1 6, and 54 and 55 Viet. c. 75). 
 Quarry Fencing Act, 1887 (50 and 51 Viet. c. 19). 
 Rivers Pollution Prevention Act, 1876 (39 and 40 Viet. c. 75). 
 Stannaries Act, 1887 (50 and 51 Viet. c. 43). 
 Truck Acts, 1831 and 1887 (i and 2 William IV. c. 37, and 
 
 50 and 51 Viet. c. 46). 
 
 The Alkali Acts were passed with a view to prevent noxious 
 and offensive gases produced in manufacturing processes from 
 being discharged into the atmosphere, or at all events to reduce 
 their escape to a minimum. These Acts apply to a few mineral 
 workings viz : 
 
 (1) Salt works in which brine is being evaporated for the manufac- 
 
 ture of snlt. 
 
 (2) Cement works in wl.ich clays are made into cement. 
 
 (3) Tin and copper mines where ores containing arsenic are being 
 
 roasted. 
 
 (4) CoHieries where tar and ammoniacal liquor, obtained from the 
 
 waste eases of coke ovens, are being treated ; the former is dis- 
 tilled for the production of paraffin and burning oils, the latter 
 is made into sulphate of ammonia. 
 
665 ORE AND STONE-MINING. 
 
 The Acts are administered by Inspectors under the Local 
 Government Board. 
 
 The Boiler Explosions Acts compel the owner of a mine to report 
 to the Board of Trade any explosion of a steam boiler, which may 
 happen at his works whether above or below ground. The Board 
 of Trade officials can then make a preliminary investigation into 
 the cause of the explosion, and afterwards hold a formal inquiry 
 if they think fit. The Court holding this formal inquiry is 
 usually composed of two Commissioners specially appointed by the 
 Board of Trade, who are endowed by the Acts with ample power 
 for punishing the owners and agents of mines, if an explosion has 
 in any way been caused by their neglect. The Commissioners 
 cannot inflict a " fine " in a criminal sense, such as is imposed by 
 a Court of Summary Jurisdiction at proceedings taken under the 
 Mines Regulation Acts ; but, where neglect has been proved, the 
 responsible persons have been ordered to pay as much as ^100 
 or ;i2O to the solicitor of the Board of Trade " towards the 
 costs and expenses of the investigation," which practically comes 
 to the same thing. Under the Mines Regulation Acts the mine- 
 owner can appeal to a superior court and have the matter re-heard ; 
 but the decision of the Commissioners under the Boiler Explosions 
 Act is final and not subject to review. 
 
 The Brine Pumping Act provides compensation for owners of 
 property who suffer through the subsidence of the ground caused 
 by the pumping of brine. The working of the Act is controlled 
 by the Local Government Board. 
 
 The Elementary Education Acts make provision for the educa- 
 tion of children : they prohibit absolutely the employment of 
 children below the age of 10, and do not permit the employment 
 of children below the age of 13 unless they have reached the 
 standard of education fixed by the by-laws in force in the 
 district. Children between 13 and 14 are allowed to work if they 
 can produce a certificate of proficiency or of previous due attend 
 since at school. After they have attained the age of 14, they are 
 no longer " children " within the meaning of the Education Acts. 
 
 The Employers' Liability Act extends and regulates the liability 
 of employers to make compensation for personal injuries suffered 
 by workmen in their service. Until this Act was passed a work- 
 man could not claim compensation for injuries due to the neglect 
 of a fellow-servant. The statute of 1880 has broken down this 
 doctrine of " common employment " to a certain extent, and has 
 made the master liable if the injury was caused by the negligence 
 of a foreman or person entrusted with superintendence ; but it 
 does not make the master liable for the negligence of all the 
 fellow-servants. 
 
 The Explosives Act regulates the manner in which licences for 
 storing explosives are obtained, the construction and maintenance 
 of the magazines at mines, the subdivision of the trade packages, 
 
LEGISLATION AFFECTING MINES, ETC. 667 
 
 and the delivery to the men. The Act is enforced by Inspectors 
 under the Home Department, and also by the Police on behalf 
 of the Local Authorities. 
 
 The two Factory and Wwkshop Acts, which are enforced by 
 Inspectors serving under the Home Department, apply to certain 
 quarries, and to surface works at mines under the Metalliferous Act, 
 such as the dressing sheds. They contain provisions for promoting 
 the health and safety of the workpeople, and regulate the hours 
 of employment of women, young persons, and children. It is 
 probable that all quarries will eventually be placed under the 
 supervision of the Inspectors of Mines. 
 
 The object of the Quarry Fencing Act is evident from its title, 
 and it is the business of the Local Authorities to see it enforced. 
 
 By section 5 of the fiivers Pollution Prevention Act, the mine- 
 owner is prohibited from discharging into streams any solid 
 matter in such quantity as to prejudicially interfere with its flow, 
 or any poisonous, noxious or polluting solid or liquid matter, 
 unless he proves that he is using the best practicable and reason- 
 ably available means to render such matter harmless. The 
 administration of this law rests with the Sanitary Authority of 
 the district, and in this, as in other matters, the work of the 
 Sanitary Authorities is supervised by Inspectors acting under the 
 Local Government Board. 
 
 The large amount of refuse which is produced in extracting 
 some minerals from their ores, makes the task of getting rid of 
 it, without polluting the rivers, far from easy ; and the miner 
 often incurs the wrath of the fisherman, who stirs up the 
 Sanitary Authorities or River Conservancy Boards into action. 
 Coarse waste, such as comes from jigging the larger sizes of 
 the crushed rock, can always be made into heaps upon the 
 land ; but the fine slimes, whether coming from stamping or 
 other dressing processes, are carried away in suspension, and turn 
 a bright trout stream into a muddy drain, or are spread over the 
 meadows in flood time, to the annoyance of the farmer. These 
 evils may be greatly lessened by providing large pits into which 
 the water from the mine is allowed to settle, and so deposit much 
 of the solid matter which it contains in suspension. Effective 
 filtering pools have been made in Germany from the coarse 
 refuse (skimpings) from the jigs. It is tipped so as to form 
 high banks enclosing a rectangular area, into which the muddy 
 water from the ** floors " is led, and allowed to form a large 
 pool. Some of the solid matter settles down on the bed of the 
 pool, as it would do in any ordinary pond, and the rest is deposited 
 in the bank itself, as it permeates through the tortuous passages 
 left between the little fragments of stone. In time, the inner 
 sides of the banks become somewhat choked with slime and the 
 percolation no longer proceeds so rapidly; this state of things is 
 remedied by letting out the water during a holiday, and scraping 
 
668 ORE AND STONE-MINING. 
 
 down the sides, so as to expose a fresh unchoked surface to the 
 slimy water. Old heaps of mine refuse can be utilised in a 
 similar manner ; the stream of dirty water led into the top will 
 escape fairly clear at the bottom. As soon as one part of the 
 heap becomes choked with slime, the out-fall of the " floors " must 
 be shifted to another part of the bank. 
 
 The Stannaries Act, 1887, was passed to remedy certain evils of 
 which miners and shareholders complained at mines in Cornwall 
 and Devon. The Act extends only to metalliferous mines and tin 
 streaming works i.e., works where tin ore is extracted from the 
 dirty water flowing away from mines, within the Stannaries. 
 The miner now has a first charge upon the property of a mining 
 company, and is less likely to lose his earnings when a mine is 
 stopped for want of funds, than he was some years ago. Surface 
 hands have to be paid once a fortnight ; miners employed by 
 contract below ground are entitled to claim " subsist " once a 
 fortnight that is to say, a payment on account equal to the esti- 
 mated amount of their earnings. Money deducted for sick and 
 accident funds has to be accounted for, and a copy of the balance- 
 sheet must be posted up in the " dry" or changing house. The 
 miners have the power to appoint a check-weigher. Meetings of 
 the shareholders of every " cost book " mine must be held at least 
 once in every sixteen weeks. Tools and materials supplied to the 
 miners have to be charged as nearly as possible at the market 
 prices. Other regulations relate to the settlement of disputes, 
 mortgages, relinquishment of shares, and registration of companies. 
 A copy of the Act has to be kept posted up in the smith's shop 
 and in the changing house of every mine. 
 
 The object of the Truck Acts is to pre\ent the mine owner from 
 making a profit out of the tools and materials which he supplies 
 to his men ; but he has a right to make deductions from the men's 
 wages for medicine, medical attendance, materials and tools, pro- 
 vided that they agree in writing to this system. As a rule the 
 men would sooner obtain the necessaries for their work in this 
 way, than purchase them at the shops in the district. The 
 Truck Acts have to be enforced at mines by the Inspectors 
 under the Mining Acts. 
 
 From the foregoing pages it is very evident that the manager 
 of a mine in this country may have to make himself well acquainted 
 with a considerable number of legal enactments, mostly of recent 
 date, if he desires, as he should do, to carry on his work in strict 
 accordance with the law. 
 
CHAPTER XVI. 
 
 CONDITION OF THE MINER. 
 
 Clothing : bat, boots, jacket Housing : barracks, cottages, changing 
 houses Education Sickness Thrifc Recreation. 
 
 IT is perfectly impossible to do justice to the importance of this 
 subject in the few pages that can be devoted to it in a general 
 text-book; but the following remarks will serve to call the 
 attention of the student to matters with which he may have to 
 deal when he enters into the active duties of his profession, and 
 becomes either an employer of labour himself, or the agent of a 
 mining company. 
 
 I propose to treat the subject under the following heads : 
 
 1. Clothing. 
 
 2. Housing. 
 
 3. Education. 
 
 4. Sickness, 
 
 5. Thrift. 
 
 6. Recreation. 
 
 i. CLOTHING. At the surface we clothe ourselves in order 
 to keep our bodies warm, and to protect ourselves from the sun 
 and rain ; in the mine the conditions are totally different, and the 
 clothing may be altered accordingly. On the whole the tem- 
 perature is more uniform than it is above ground ; the miner in 
 most cases finds his working-place warmer in winter and cooler 
 in summer than it would be if he were working in the fields in 
 the neighbourhood. It is the exception to have the temperature 
 below 32 F. in mines even in winter. Occasionally in this 
 country a freezing wind rushing down the shaft will coat the 
 ladders with ice and make climbing unpleasant and risky, and 
 where the climate is cold and the openings to the surface large, 
 the effects of frost are felt far deeper than they are here. The 
 sinkings through alluvial deposits in Siberia are instances of 
 great cold in mines; and even where the operations are more 
 truly underground the temperature is sometimes below freezing 
 point. This is the case at the Algachi silver mine.* 
 
 The other extreme was found in the workings on the Comstock 
 
 * Kennan, " In East-Siberian Silver Mines," The Century Magazine, 
 vol. xxxviii., 1889, p. 803. 
 
670 ORE AND STONE-MINING. 
 
 lode.* In the year 1868, when a depth of 1000 to 1200 feet had 
 been reached, the heat in some drifts was becoming unbearable. 
 In August 1868 at a depth of 1 100 feet in the Chollar-Potosi Mine, 
 the temperature was 100 F. (37' 7 C.),and in the lower level of the 
 Hale and Norcross 1 10 F. (43 -3 C.) In June 1870 at the goo-foot 
 level of the Yellow Jacket Mine the temperature was 97F.(36*i C.) 
 at a point only 300 feet from the shaft, although blowers were at 
 work. The highest temperatures were observed when long levels 
 were driven without any ventilating shafts or winzes. As soon as 
 a proper air-current was established the temperature usually sank 
 rapidly. Thus the thermometer stood at 130 to 140 F. (54 to 
 60 C.) in a drift at the i85o-foot level of the Bullion Mine, but 
 when connection was made with another shaft the thermometer 
 went down to 100 F. (377 C.) The miners working in the hot 
 levels were supplied with ice, which was sent down by the ton. 
 Their average daily consumption in the hottest parts of the 
 California and Consolidated mines during the summer of 1878 
 was 95 pounds of ice per man, and they would commonly drink 
 as much as three gallons of water in the shift of eight hours. 
 
 It was not only the air of the mine which was hot, the water 
 was even hotter. The spring in the Savage mine had a tempera- 
 ture of no less than 157 F. (69-4 C.), and the incline was tilled 
 with scalding vapour. Up to the end of 1877 * ne highest recorded 
 temperature of the water was 154 F. (677 C.) ; but since then an 
 increase in the water temperature to 170 F. (76'6C.) has been 
 noted. The Comstock mines are the hottest in the world. 
 
 At Dolcoath,t the largest and deepest tin mine in Cornwall, the 
 temperature of the water issuing from the rock in the lowest 
 workings is nearly 100 F. (377 C.) and that of the air 96 F. 
 (35'5 G-) ^ ne bottom level is now 2424 feet vertically below the 
 surface. 
 
 In the adjacent Cook's Kitchen mine, which approaches its 
 neighbour in depth, the air in the end of the 394-fathom level, at 
 no great distance from a winze, will raise the thermometer to 
 95 F. (35 C.), whilst in the ends of the 420-fathom level, driven 
 out but a very short distance from the bottom of the shaft, the 
 temperature of the air is 100 F. (377 C.) and that of the water 
 slightly higher. Some workings for copper at St. Day, Cornwall, 
 were even hotter, but the mine has long been abandoned. The 
 submarine mines near the Land's End are also warm, and air- 
 temperatures above 90 F. (32 C.) are often recorded. In Corn- 
 wall, as in Nevada, the hottest places are "ends" or "rises" 
 before they are " holed " to other workings. When once a com- 
 munication has been effected and a through draught established, 
 the rock-faces cool down quickly. 
 
 * Lord, "Comstock Mining and Miners," Monographs U.S. Geol.Survey t 
 Washington, 1883, p. 391 et *eq. 
 
 f MS. information from Mr. W. Thomas, F.G.S., 1893. 
 
CONDITION OF THE MINER. 671 
 
 With the temperatures just mentioned, it is evident that the 
 miner requires very little clothing, but even when the air is 
 comfortably cool, he often strips himself to the waist, in order to 
 secure that freedom of limb which so much conduces to the 
 efficiency of muscular labour. 
 
 In some cases, such as in the salt mines of this country, 
 the working-places are very comfortable; indeed the miner is 
 better off than the labourer at the surface. He is not exposed to 
 the burning sun, cutting winds or torrents of rain ; but he works 
 in a cool and pleasant atmosphere, varying little in temperature, 
 and he has not to assume a cramped posture. On the other hand, the 
 miner's working- place may be moist and steaming, or hot, dry and 
 dusty, or cold, wet and draughty ; and on reaching the surface in 
 a cage, he may have to face an icy blast after leaving a tropical 
 atmosphere only a minute or two before. Where circumstances 
 are so unlike, the clothing worn in the mine must necessarily vary, 
 to say nothing of differences in attire due to the habits of the people. 
 The South African native, content with a waist-cloth above 
 ground, requires nothing more when he descends into the diamond 
 mines, whilst the white man, true to his bringing up, needs, or 
 thinks he needs, more abundant vestments. 
 
 Hat. Some of the clothing used below ground has to serve a 
 different purpose to that required of it at the surface. One object 
 of the miner's hat is to preserve his head from blows, as he walks 
 along low and rugged tunnels, and from falls of stones while work- 
 ing in shafts. The Oornishman wears a hat made of felt and 
 robin, shaped like an ordinary " pot hat " of everyday life. It is 
 cheap and durable, and affords admirable protection against hard 
 raps ; but it is not ventilated, and it is heavy, weighing about one 
 pound, or four times as much as an ordinary felt hat. Under it 
 the Cornishman wears a cap of calico or linen, which often con- 
 stitutes the headgear in the working place itself, whilst the hard 
 hat is donned in going to and from the surface. A few gimlet 
 holes improve the Cornish hat, by affording a little vent for 
 the perspiration given off so freely when climbing ladders in warm 
 shafts. 
 
 The Cornish hat is serviceable as the brim keeps the neck 
 dry, and in sinking very wet shafts a waterproof flap can be 
 added, so as to increase the amount of protection. Lastly, 
 the lump of clay used as a candle- holder can be easily and 
 safely stuck upon the hat, leaving the miner both hands free 
 when he is climbing about the workings by rope, chain or 
 ladder. 
 
 The British miner, working upon seams of stratified ironstone, 
 affects a leathern cap, which he wears with the small peak turned 
 towards the back. It is far lighter than the Cornish hat, but it is 
 not capable of resisting so hard a blow. 
 
 In France a leathern hat, in shape like the Cornishman's, 
 
672 ORE AND STONE-MINING. 
 
 is common. It is made of thick solid leather, and is therefore very 
 strong and durable, but it is heavy and expensive. 
 
 In some parts of Germany the miner wears a brimless hat, 
 something like a busby, made of loose-textured felt, thick enough 
 to prevent a tolerably hard knock from doing any harm, and yet 
 porous enough to admit the passage of perspiration. In sunless 
 workings a brim is not required for guarding the eyes, and in dry 
 mines the German hat with an undercap of linen forms a very suit- 
 able head covering. It is light, weighing only about half a pound, 
 and it can be folded, which is an advantage if one is travelling. On 
 the other hand, its porosity and its want of a brim render it 
 unfitted for very wet places, and it cannot be used for carrying the 
 candle in the same way as the Cornish hat. 
 
 The hat of the Mansfeld copper miner is made of thick black 
 felt and weighs half a pound ; it has a broad brim which is turned 
 up in front and covered with leather. A piece of wire sewn on 
 under the leather serves as a hook for carrying the lamp on the 
 head, though, now that the shafts are mostly provided with cages, 
 there is little ladder work to make this necessary. The felt is thick 
 enough to save the head if struck, and the brim protects the neck 
 from drops of water. It is a light, comfortable and cheap hat. 
 
 In sinking oil wells in Roumania, the miner adopts a conical hat, 
 shaped like that of the Chinaman, but made of tinplate, which 
 serves to keep off the drops of water and petroleum. 
 
 Looking at the number of accidents from falls of roof, to say 
 nothing of accidents from things falling down shafts, the nature 
 of the head-gear adopted by the miner is not without importance. 
 It is especially necessary that shaft-sinkers should be careful to 
 have suitable hats. An ideal hat would be light, but strong, well- 
 ventilated, and with brim enough to prevent water from running 
 down the neck. 
 
 Boots. Turning to the other extremity of the body, it is fre- 
 quently noticed that the Cornishman, though careful about his 
 head, pays very little attention to his feet. He often has to 
 walk through wet levels, and knowing that he cannot reach his 
 working-place dry-shod, he is quite content with any dilapidated 
 foot-gear. Unfortunately this carelessness is sometimes the cause 
 of accidents, for men have been known to slip from ladders from 
 wearing shoes which did not give them a proper foothold. 
 
 In some of the Welsh ore mines the clog is very commonly 
 worn ; it is a boot with wooden soles and leather " uppers." The 
 sole is protected from too rapid wear by irons at the bottom and 
 sides. Many miners like clogs, as the wooden sole is warmer than 
 leather, and consider that they are less likely to slip than ordinary 
 boots or shoes in climbing up and down ladders or steep 
 "stopes." I can well imagine that the stiff wooden sole 
 gave a better foothold on the vertical ladders of the Flint- 
 shire mines years ago than yielding leather. The clog has the 
 
CONDITION OF THE MINER. 673 
 
 further merit of cheapness, but the unbending sole renders 
 it therefore less comfortable than the ordinary foot-gear for much 
 walking. Men who use clogs below ground often walk to and 
 from the mines in leathern boots or shoes. 
 
 The Festiniog " rockman," whose working-place lies among 
 smooth surfaces of slate, trusts to a strong laced boot well shod 
 with nails to prevent his slipping, while he climbs about chain in 
 hand. Another reason for the strong foot-covering is the fact 
 that the fragments of rock are often sharp and cutting. 
 
 Many miners in France still wear the clumsy but cheap wooden 
 shoe or "sabot," whilst in Spain they have sandals made of 
 esparto grass. These cost only $d. or 3^. per pair, and last from 
 three weeks to a month. Lastly, when we travel further afield, 
 we find the hardy miner going barefoot, provided by nature alone 
 with a tough outer tegument, which gives him a better hold on 
 rock or ladder than any which art can furnish. , 
 
 Jacket. Little need be said about the clothing of the worker 
 at the surface, save that where he is engaged near machinery 
 it is advisable that the jacket should fit closely. Accidents have 
 happened from loose clothing being blown on to revolving gearing 
 or shafting, which could not be stopped until the unfortunate 
 workman had been drawn in and mangled. 
 
 As has been already explained, it is necessary from time to 
 time to clean out the flues in which arsenic has collected from 
 the calcination of ores containing mispickel. Under the Special 
 Rules in force at some of the Cornish mines, the owner has to 
 provide suitable clothing for this work ; probably the best is a 
 combination suit consisting of jacket and trousers in one garment, 
 such as is used for going into boilers. The legs of the trousers 
 should be tied round the ankles, and the sleeves round the wrists, 
 in order to prevent any particles of arsenic from finding their 
 way to the skin and so doing mischief. 
 
 2. HOUSING. It may or may not fall to the lot of the 
 mine-owner to provide dwellings for some or all of his workmen, 
 but in any case it is his duty to interest himself in the question 
 of the living accommodation for them and their families. Even 
 if he is not moved by considerations of a humanitarian nature, as 
 he certainly ought to be, the mine-owner must recognise the fact 
 that it does not answer commercially to let his men fall sick, become 
 prematurely unfit for work or die at an early age ; nor does it pay 
 to have the working staff constantly changing. A valuable horse 
 is put into a good stable, is well tended and not overworked, 
 if the master wishes to derive as much profit as possible from it ; 
 and it cannot be expected that the best results will be got from 
 the miner's labour, unless he is treated with at least as much con- 
 sideration as the lower animal. Therefore on the score of profit 
 as well as upon the score of humanity, the mine-owner should 
 insist upon proper dwellings being available for his men. 
 
 2 u 
 
674 ORE AND STONE-MINING. 
 
 When mining is carried on in the midst of a fairly populous 
 district, private enterprise may often be relied on for providing 
 suitable cottages, nevertheless even here the mine-owner may do 
 good by calling the attention of the local authorities to insanitary 
 dwellings or cases of overcrowding. It frequently happens, 
 however, that mines are worked in out-of-the-way places, where, 
 at all events in the early days of the enterprise, there is a total 
 absence or utter inadequacy of accommodation for the workpeople. 
 The mine-owner is then obliged to take upon his own shoulders 
 the burden of providing dwellings. Two classes may be erected : 
 
 (1) Barracks, which serve for unmarried men, or for married 
 men whose homes are not within the reach of a daily walk ; 
 
 (2) Cottages for married couples and their children. 
 Barracks. Excellent examples of barracks are found, for 
 
 instance, at the Mechernich lead and the Mansfeld copper mines, 
 owned by two enlightened and prosperous companies. The large 
 workmen's hotel at Mechernich is capable of accommodating 
 about 400 men. The workmen are perfectly free to do as they 
 like, as regards living in the barracks or not ; but if they do live 
 there, they must conform to the regulations. 
 
 The cost of lodging is gd. per week ; for this a man gets a 
 comfortable bed with a spring mattress, and clean sheets and 
 blankets. The beds are such as I would sleep in without hesi- 
 tation. The space allowed in the bedrooms is 400 cubic feet per 
 man, and in winter the rooms are warmed by hot air. They 
 are kept scrupulously clean, and the men are obliged to change 
 their working clothes as soon as they come in, and put on other 
 suits. 
 
 The men can be supplied with their meals at stated hours in 
 the large dining hall at low prices, and boiling water is always 
 ready for them gratis, so they can make coffee from their own 
 store if they like. The dining hall has a tiled floor, and the 
 tables are scrubbed until they are exquisitely clean. 
 
 The sanitary conveniences are ample and well kept, and the 
 men can have warm shower-baths free of cost. 
 
 The mental comforts are not forgotten. There is a reading- 
 room, with newspapers, which is open after working hours, and a 
 library, from which the men can borrow books. 
 
 At the Mansfeld copper mines the company have provided no 
 less than nine barracks, capable of accommodating 2268 men 
 and 48 females. The barracks at Eisleben, which will house 350 
 men, are represented in Figs. 700 and 701, taken from the long 
 and careful report of Oberbergrath Taeglichsbeck.* The house is 
 a three-storey brick building, with bedrooms for nine, ten, or eleven 
 men each. In accordance with official regulations, there is an air 
 
 * " Die Wohnungsverhaltnisse der Berg- und Salinenarbeiter im Ober- 
 b^rgamtsbezirke Halle, einschliesslich cler Mansf elder Hiittenarbpiter," 
 Zeitschr.f. B.- H,- u. S.-Wesen im Preuss. Staate, vol. xl. 1892, p. 44. 
 
CONDITION OF THE MINER, 
 
 FIG. 700. 
 
 Front Elevation. 
 FlG. 01. 
 
 5METRES 
 
 Ground Plan. 
 
 SCALE 
 
 10 
 
 20 METRES 25 
 
 IOFEET 
 
 20 
 
 30 40 
 
 50 
 
 60 
 
 70 FEET80 
 
ORE AND STONE-MINIXG; 
 
 space of 350 to 400 cubic feet (to to n cubic metres) per man. 
 miocimfiaieheiaedwithhcitaviAwmtor.aAdt^isalarge 
 dming-haU adjoining the kitchen, in a separate boflding, connected 
 with the dormitories by a covered way. This building e** 
 ^9370, including a house for the steward; who superintends 
 everything, and laying on water. The barracks are built in 
 
 tioos, and are mostly surrounded by gardens. They are 
 
 with all sorts of 
 
 The men lodging at the barracks 
 
 day for their board; f or breakfast each mm gets J Hire of 
 and milk; for dinner n litre (2 pints) of thick soup or 
 tables, with i KL ( 4 | OBS.) of beef or pork, weighed aftw cooking 
 booe; 
 
 for supper if litres (3 pints) of thick 
 with suet, or coffee and milk. In addition to this, he 
 loaves of bread, each weeing 3 kO. (6-6 Ib*), 
 
 til. (J Ux) of butter, and the same amount of 
 refer it can take ham, suosage 
 
 prefer it can take ham^saosage, or bacon instead of the butter 
 andfat For lodgings, lights, and firing, etch boarder has to pay 
 o*L(5a) per day in summer and o-o* (8 j)perday in winter. 
 Order and cleanliness am enforced by a code of regu 
 
 to be strictly observed by att the boarders. The 
 
 The bariack system is also found in this country, especia% in 
 North Wales, but not on so large or so sumptuous a scale as in 
 
 Germany. In Wales the men often skep two ina bed, 
 mattresses; and, as a rale, there is not a: 
 are there any arrangements for supplying meak. Oneseesthe 
 men arrive on a Monday morning, carrying their provisions for 
 the week on their backs; and they cook their food themselves by 
 the cxNnmon fire of the eating and deeping apartment. Often 
 there is no person provided for keeping the rooms clou, and the 
 
 * _ *7 A. 5? 
 
 of some of Weevils. I have seen hunks 
 for 21 meninaroom without a window or a chimney, 
 od containing only 2200 cubic fact of 
 
 of the " ~ - 1 * *" s -* = * ~' 
 
 If 
 
 to femgn thorn; 
 
 dd be separate from the dormitories, and the 
 house should be kept dean and tidy. 
 
 The most extensive development of the barrack system in any 
 British possessions is at the Kimhedey 
 the particular exigencies of the case have led toa 
 which is not found elsewhere. One great difficulty of 
 
CONDITION OF THE MINER. 677 
 
 mining in the early days was the prevention of thefts of valuable 
 stones. Gems of great value can be so easily secreted about the 
 person, or indeed swallowed, that the mine owner could be, and 
 wavS, robbed with little fear of detection. It is true that since the 
 passing of the Illicit Diamond Act, the disposal of stolen diamonds 
 has become more difficult, but the protection afforded by this 
 statute does not entirely suffice. The plan now adopted with the 
 native miners is to confine them for the length of their contract, 
 often three months, and not allow them on any pretext to leave 
 the company's premises. They go straight from their barracks 
 to the mine by a securely enclosed way, and return to them as soon 
 as work is over. The barracks consist of one-storey buildings, made 
 of corrugated iron, arranged so as to form the four sides of a 
 large square, and divided into rooms holding about twenty natives 
 each. The "compound,"* as it is called, often covers several 
 acres ; and it is surrounded by a high iron fence 10 feet from the 
 building. The natives can procure all the necessaries of life from 
 a store within the compound, whilst food and water are supplied 
 free. A large swimming bath enables them to enjoy a dip when- 
 ever they like. If perchance a man falls ill, he is taken to a 
 hospital, also belonging to the company. 
 
 Of course, this system would not find favour with European 
 miners, who would resent the enforced confinement and regard it 
 as an irksome imprisonment ; but the native, with fewer wants, 
 is quite content to put up with the temporary loss of liberty for 
 the sake of getting good wages. 
 
 Cottages. Enough has been said about barracks, and we may 
 now pass on to cottages for families. At many of the collieries 
 of this and other countries, great attention has been paid to the 
 erection of workmen's villages, and a large amount of capital has 
 been sunk in providing comfortable and convenient dwellings. 
 It is an advantage to the mine-owner to have his men on the 
 spot, coming to their work without the fatigue of a long walk ; 
 and it is a benefit to the man to have his home within easy reach. 
 When, therefore, the preliminary explorations and workings have 
 revealed the existence of enough mineral to supply a mine for a 
 number of years, a company is thoroughly justified in spending 
 money upon houses. 
 
 Figures 702 to 705 represent the type of miner's cottage lately 
 erected by Mr. Emerson Bainbridge for the Bolsover Collieries in 
 Nottinghamshire. It will be seen that each cottage has a good 
 living-room and scullery on the ground floor, two good bedrooms 
 on the first floor, and an attic above. 
 
 Many a workman, however, would rather be his own landlord, 
 and not feel the restraint of living in a cottage belonging to the 
 company, because he may have to quit it if he goes to work at 
 
 * Second Annual Report of the De Leers Consolidated Mines, Limited, for 
 the year ended March 1890, p. 23. 
 
6yS 
 
 ORE AND STONE-MINING. 
 
 another mine, or because he feels the natural ambition of wishing 
 to own a house himself. In order to encourage this very laudable 
 object, mining companies often make it easy for the workman to 
 buy his cottage by small instalments, and they thus gather around 
 their mines a number of small householders, who are less likely 
 to encourage disturbances than men who have no sj eciil interest 
 in the preservation of order. To the workman there tie advantages 
 
 FIG. 702. 
 
 FIG. 703. 
 
 _ 
 
 ELCVA710V 
 
 FIG. 704. 
 
 BACK ELCVATJOH 
 
 FIG. 705. 
 
 ./-' f LOO ft PLAN 
 
 as well as disadvantages ; if the cottage belongs to him, he has a 
 feeling of independence, and he does not mind spending money to 
 embellish or improve it, which he would not do if it were the pro- 
 perty of somebody else. The purchase may be a wise and profitable 
 one, if he feels pretty sure that he is going to spend all his days in 
 one place ; but this fixedness to one district cannot always be 
 assured or advised. Wages may be better in an adjoining county 
 or in some foreign land, mining may decline at home or entirely 
 cease, and a move may become a necessity, with no chance of 
 selling the cottage property. Under such circumstances the 
 earnings spent in buying a cottage will have been badly invested. 
 
CONDITION OF THE MINER. 
 
 679 
 
 It also happens that during a period of high wages, a man is 
 tempted to arrange for the purchase of his house with one of the 
 numerous building societies, and he agrees, for instance, to pay 
 i per month for ten years, at the end of that time becoming 
 the owner of a house worth .120. If his wages are ^7 a 
 month he can manage the monthly instalments without difficulty ; 
 but let wages drop to ^5, and he will find it far less easy to keep 
 up his payments. 
 
 As an example of the manner in which workpeople are housed, 
 I will again extract some figures from Taeglichsbeck's report.* 
 For the Halle district he gives the following numbers and pro- 
 portions : 
 
 
 
 Kind of Dwelling-house and Percentage of 
 the Total Number of Persons. 
 
 
 Rent free, 
 but Rent 
 reckoned 
 as part 
 of Wages. 
 
 Living in 
 their own 
 Houses. 
 
 Living in 
 hired 
 Houses. 
 
 Living in 
 Barracks, 
 &c. 
 
 Workmen. 
 Private works (40,372 persons) 
 Government works (3274 persons) . 
 Officials. 
 Private works (1196 persons) 
 Government works (122 persons) . 
 
 0'S3% 
 0-36% 
 
 45-82% 
 
 7377% 
 
 2r85% 
 27-92% 
 
 I7'23% 
 9-84% 
 
 7o-ii% 
 7ri4% 
 
 36-95% 
 16-39% 
 
 7-51% 
 0- 5 8% 
 
 He further shows that 25 per cent, of the persons employed at, 
 the Mansfeld copper mines are living in their own houses, of which 
 nearly one quarter have been purchased with the assistance of the 
 Company. 
 
 Before concluding this subject of housing, a word may be said 
 about the " dries," or changing houses, which have to be provided 
 at mines under the Metalliferous Act, when more than twelve 
 persons are employed below ground. Such a house is very 
 necessary when the men come up wet and dirty, and often soaked 
 with perspiration from working in hot places or from climbing 
 long r.uns of ladders. They then change all their clothes, and 
 leave them to be dried ready for use on the following day. One 
 of the best modes of heating a " dry " is by steam ; the shell of 
 an old boiler is placed along the centre of the house and is supplied 
 with steam from any convenient source. Owing to the large 
 surface of the shell the room is speedily heated, and the clothes 
 hung about it are quickly dried. The water condensing from 
 the steam may be drawn off by a cock and used for washing 
 purposes. Figs. 706 and 707 represent the changing house erected 
 at Levant Mine in Cornwall by Mr. Eustice, which has the 
 advantage of being put into communication with the man-engine 
 shaft by a passage and staircase, so that the men stand no risk of 
 * Op. cit. p. 7. 
 
63o 
 
 ORE AND STONE-MINING. 
 
CONDITION OF THE MINER. 
 
 681 
 
 exposure to the fierce breezes coming straight off the Atlantic, 
 which might sometimes be trying after the underground warmth. 
 It is heated by rows of hot-water pipes. 
 
 The floor of the " dry " should be made of cement and not of 
 boards, to permit the application of the hose for washing it. 
 Benches and lockers should be removable in order to facilitate 
 the cleaning, which is frequently necessary, considering the 
 amount of dirt which cannot fail to accumulate in such a 
 place. A wooden floor has the disadvantage that the boards are 
 sure to shrink under the constant warmth, and when once full of 
 
 FIG. 708. 
 
 gaping chinks it can never be effectually cleaned ; besides, there 
 is the danger from fire, either from matches left carelessly about 
 or from the men smoking in a place where the wood gets as dry 
 as tinder. The walls should be whitewashed at regular and 
 frequent intervals, in order to keep the place thoroughly sweet. 
 
 It is not difficult to give the miner the luxury of a shower- 
 bath at a small cost, and it seems to me far better that the miner 
 should change and perform all necessary ablutions at the mine, 
 than go home in his underground clothes, and depend upon the 
 resources of his cottage for washing himself and drying his working 
 apparel. 
 
 At the Anzin collieries, in the North of France, a large number 
 of shower-baths (Fig. 708), are provided at the different shafts, bo 
 
682 ORE AND STONE-MINING. 
 
 that the men have not to wait for their turn . The Anzin arrange- 
 ments are excellent, and might be copied with advantage at 
 some of our mines. 
 
 3. EDUCATION". The school education may be of two 
 kinds, general and technical. In this and other countries, where 
 the primary education is free, the mine-owner need not concern 
 himself with providing schools and teachers ; but where the State 
 does not take this paternal care of the rising generation, a certain 
 responsibility for the young is often felt by the shareholders of 
 the mining companies, and they endeavour to equip the children 
 of their workmen, at all events, with the three R's. 
 
 For carrying on mining, it is not sufficient merely to provide 
 strong bones and well-developed muscles; there must also be 
 brains, or, in other words, no matter how good the miners are, 
 their work must be directed by trained engineers and competent 
 foremen. The latter may well be recruited from among the actual 
 working men, who should have some general knowledge of science 
 and some special training in the various branches of their pro- 
 fession. 
 
 This scientific and technical training is frequently provided by 
 the large foreign mining companies at their own expense. The 
 best of the young men attend classes out of working hours, and 
 thus manage to cirry on their lecture-room teaching hand in 
 hand with the practical instruction which they are acquiring in the 
 mine itself. 
 
 In this country the education of the young miner is largely 
 aided by classes held in the evenings, under the auspices of the 
 Science and Art Department, the City and Guilds of London 
 Institute, and some of the County Councils. The energetic and 
 ambitious workman can nowadays obtain instruction in mathe- 
 matics, mechanics, chemistry, physics, geology, the principles of 
 mining, ore-dressing, assaying and mine-surveying in any large 
 town and often in outlying villages. To those preparing to pass 
 the examination for a certificate under the Coal Mines Act, these 
 classes are very valuable. 
 
 The success of local schools and classes depends a good deal 
 upon the attitude assumed by the managers of mines in the 
 neighbourhood. If educational work is pooh-poohed by the 
 masters, the men follow suit and the teaching languishes. On 
 the other hand, if the head-piece of the school is one of the chief 
 mining engineers of the district, pupils flock to the lecture-rooms 
 and laboratories, and success is almost a certainty. By forming 
 and encouraging these local schools or classes, owners and 
 managers of mines are not only promoting the welfare of the 
 rising generation around them, but they are at the same time 
 doing good to mining generally, and are contributing to the intro- 
 d action of the most improved methods of extracting minerals, 
 as the success of an army depends largely upon its trained 
 
CONDITION OF THE MINER. 683 
 
 non-commissioned officers, so the prosperity of a mining enter- 
 prise is largely influenced by the competency of the foremen ; 
 many of them by virtue of their talent and industry rise from 
 the ranks and become excellent managers of mines. 
 
 The training of foremen must not be carried on to the exclusion 
 of all thought for their sisters, who will make better wives and 
 mothers if they receive some instruction in the arts which belong 
 more particularly to the domain of women, such as housekeeping, 
 cookery and nursing. Teaching of this kind becomes more than 
 ever necessary in localities where females are largely employed on 
 the dressing noors, for then the girls fail to receive that practical 
 training in household work, which would otherwise fall to their 
 lot, if they entered domestic service, or assisted their mothers in 
 their own homes. 
 
 4. SICKNESS. At first sight it might be supposed that 
 mining is necessarily an unhealthy occupation, that confined 
 for hours in dark and gloomy passages a man cannot keep well 
 and strong. Stubborn facts and figures show that a general asser- 
 tion of this kind is not well-founded ; but nevertheless the miner 
 does suffer in some cases from diseases inherent to his calling, 
 and these can be best combated if their causes are thoroughly 
 understood by all who are connected with mining operations. 
 
 The diseases to which miners are most liable have been care- 
 fully studied by Dr. Ogle,* who with infinite pains has worked 
 out the death-rates for mining, as well as for other occupations, 
 from the figures contained in the national register of deaths. 
 Of course it is very difficult, if not impossible, in comparing the 
 death-rate of the miner with that of some other working man, 
 to say precisely how much of the difference is due to the effect of 
 the calling. The miner is to a certain extent a picked man ; the 
 weaklings of a family do not go to work underground, conse- 
 quently in the race of life the miner has, so to say, a start, which 
 ought ceteris paribus to make him a winner. The actual death- 
 rates of some occupations are given in the table on p. 684, 
 extracted from Dr. Ogle's much more complete list. The com- 
 parative mortality figure affords the easiest means of contrasting 
 the differences between the various callings as regards healthiness. 
 The figure 1000 represents the total number of deaths among a 
 certain number of male persons between the ages of 25 and 65 
 for the whole of England ; then taking the same number of 
 'persons in any particular calling at the same ages, Dr. Ogle 
 has calculated the corresponding number of deaths. The lower 
 the figure, the healthier the occupation. In very healthy dis- 
 tricts the mortality figure is as low as 804, that of the agricul- 
 tural labourers is only 701. If we take miners, we do not find 
 a high mortality figure for the collier, nor for the ironstone 
 
 * /Supplement to the Forty-fifth Annual Report of the Registrar of Births, 
 Deaths and Marriages in England. London, 1885, pp. xxv., et seq. 
 
684 
 
 ORE AND STONE-MINING. 
 
 miner ; but the figure for Cornwall is appalling. Mining coal 
 and ironstone appears to be less fatal to life than baking bread or 
 making boots and shoes. 
 
 
 Mean Annual Death-rates per 
 
 S 
 
 > be . 
 
 
 looo liviug. 
 
 l i 
 
 
 1860-1-1871. 
 
 1880-1-2. 
 
 c""^ 
 
 OCCUPATION'. 
 
 
 
 8 
 
 
 Years of Age. 
 
 Years of Age. 
 
 Years of 
 
 Age. 
 
 
 25-45' 
 
 45-65- 
 
 25-45. 
 
 45-65. 
 
 25-65- 
 
 All males .... 
 
 11-27 
 
 23-98 
 
 10-16 
 
 25-27 
 
 1000 
 
 Males in selected healthy I 
 districts f ' 
 
 
 
 8-47 
 
 1974 
 
 804 
 
 Baker . . . 
 
 10-72 
 
 26-39 
 
 870 
 
 26-12 
 
 958 
 
 Blacksmith . 
 
 10*07 
 
 23-88 
 
 929 
 
 25-67 
 
 973 
 
 Boilermaker 
 
 
 
 
 
 9-27 
 
 26-65 
 
 994 
 
 Builder, mason, bricklaver 
 
 11-43 
 
 27-16 
 
 9-25 
 
 25'59 
 
 969 
 
 Butcher 
 
 13-19 
 
 28-37 
 
 12 10 
 
 29-08 
 
 1170 
 
 Carpenter 
 
 9 '44 
 
 21-36 
 
 777 
 
 21-74 
 
 820 
 
 Fisherman . 
 
 11-26 
 
 15-84 
 
 8-32 
 
 19-74 
 
 797 
 
 Miner, coal . 
 
 
 
 
 7-64 
 
 25-11 
 
 891 
 
 ,, ironstone 
 
 
 
 
 
 8-05 
 
 21-85 
 
 834 
 
 Cornwall 
 
 11-94 
 
 4*73 
 
 14-77 
 
 53-69 
 
 1839 
 
 Labourer, agricultural . 
 
 
 
 7-13 
 
 17-68 
 
 701 
 
 Plumber, painter, glazier 
 
 12-48 
 
 34-66 
 
 11-07 
 
 32*49 
 
 1202 
 
 Quarrier, stone and slate 
 
 10-88 
 
 28-67 
 
 9'95 
 
 31-04 
 
 1122 
 
 Tailor .... 
 
 12*92 
 
 24-79 
 
 1073 
 
 26-47 
 
 1051 
 
 Shoemaker . 
 
 10-39 
 
 22-30 
 
 
 23-36 
 
 921 
 
 The diseases inherent to the miner's calling are due to the 
 following causes : 
 
 Breathing a polluted atmosphere. 
 Excessive ladder climbing. 
 Working in cor strained positions. 
 Exposure to heat and cold. 
 Working in compressed air. 
 
 Of these various causes the first is undoubtedly by far the worst : 
 it brings on phthisis and other diseases of the respiratory organs. 
 There is nearly six times as great a mortality from these diseases 
 among Cornish miners as there is among fishermen. The 
 manner in which the air of mines is polluted has been explained 
 in the chapter upon Ventilation viz., by the breathing of the men 
 and animals in the pit, the combustion of lamps or candles, exhala- 
 tions of decaying timber, smoke of explosives, natural emanations 
 
CONDITION OF THE MINER. 685 
 
 of gases, and dust. It is the opinion of the best qualified judges 
 that dust is largely responsible for the respiratory ailments from 
 which the miner so often suffers. The difference between tho 
 atmosphere of a mine and that of the external atmosphere is often 
 made very plain by the state of the nostrils after a few hours 
 spent in underground workings; it is found that they have 
 strained off a part of the solid particles floating about in the air 
 of the mine, and the amount so arrested will serve as some gauge 
 of the quantity inhaled. Besides, men commonly breathe a great 
 deal through the mouth, and lose the benefit of their natural 
 air- filter. 
 
 The dust acts mainly mechanically, but in a few exceptional 
 cases its evil effects are due also to poisonous chemical properties. 
 The mechanical action is at first an irritation of the delicate lining 
 membrane, and then the particles make their way into the tissues, 
 choke them and harden them, and so render them unfit for 
 allowing the chemical action of the air upon the impure venous 
 blood which is necessary to life. The diseases caused by the 
 inhalation of dust in this way are bronchitis, shortness of breath, 
 asthma and consumption. 
 
 A large proportion of the dust is produced in the process of 
 boring holes for blasting in an upward direction. If the hole has 
 a downward inclination the miner puts water in, which not only 
 prevents any dust, but also renders his work easier by allowing the 
 edge of the tool to act more fairly against the rock. When, on the 
 other hand, the miner is boring upwards, the dust is scraped out 
 or falls out, and though the coarsest particles may at once drop to 
 the ground, the very fine and light ones float about, and produce a 
 cloudy and noxious atmosphere. If machine drills are employed, 
 the amount of dust produced in a given time is often considerable, 
 as will be instantly recognised by any one dressed in a dark suit 
 who stands by one of these machines while it is working in dry 
 ground. 
 
 Prevention is better than cure, and the evil consequences can be 
 averted by forcing a jet of water into the hole during the boring 
 operations. The jet may be produced either by allowing the com- 
 pressed air to act upon the surface of a tank containing water, or 
 by bringing down a supply in a pipe from a tank situated at a 
 higher level ; keeping the sides of the level moist is another 
 precaution, the particles of dust wafted against the wet sur- 
 jface are caught, like flies upon sticky paper, and so rendered 
 harmless. 
 
 Some of the dust arises from the rock being broken up in the 
 process of blasting, and some comes from the explosive itself, 
 if it consists, for instance, of infusorial earth mixed with nitro- 
 glycerine. 
 
 A fine spray is very effective in laying the dust and fumes pro- 
 duced by blasting, arid an easy method of producing it is to 
 
686 ORE AND STONE-MINING. 
 
 turn a jet of compressed air into a pipe supplied with water.* 
 An appliance of this kind is specially desirable when the blast- 
 ing in an "end" is done by volleys, when the miner has to walk 
 into the smoke of one blast in order to charge another set of 
 holes. Some men make use of a sponge as a respirator while 
 exposed to the dust and fumes, and no doubt with good effects ; 
 but it is well to delay the return as long as possible, unless the 
 " end " is provided with such an apparatus as Teague's ventilator, 
 which speedily withdraws all noxious fumes from the working 
 place. If it is necessary in some particular case to go into an 
 " end " full of smoke, the harmful effects may be reduced by 
 making use of Nature's respirator, namely, the nose, and not 
 breathing at all through the mouth. 
 
 Dusts which have a poisonous effect are those of certain minerals 
 containing arsenic, lead and mercury. 
 
 According to Dr. Harting and Dr. Hesse,f cancer in the lungs 
 is not uncommon among the men working in the cobalt mines of 
 Schneeberg in Saxony, and they ascribe the disease to dust 
 containing arsenic in combination with cobalt, which produces a 
 permanent chemical irritation in the delicate air-passages. It seems 
 to be mainly the mineral speiscobalt or smaltite (CoAs 2 ) which is 
 the source of the disease , the cobalt minerals containing sulphur 
 in addition to the arsenic are far less poisonous, as they are less 
 readily decomposed. When one reflects how soon cobalt bloom, 
 the hydrated arseniate of the metal, is formed upon the ores in a 
 damp atmosphere, it is not surprising that a similar action should 
 go on with minute particles of smaltite imbedded in the lung 
 tissue, and eventually set up a considerable amount of irritation. 
 
 Far more dangerous than the dust of arsenical minerals under- 
 ground, are the fumes produced in roasting ores containing mis- 
 pickel, a process which goes on in many tin mines and some gold and 
 copper mines. Particles of arsenious acid attach themselves to the 
 skin, in places where it is moist from perspiration, and produce 
 nasty sores, whilst those which enter the body give rise to various 
 disturbances of the digestive organs. The best means of avoiding 
 the ills due to arsenic have been pointed out by Hirt J at some 
 length. Only thoroughly healthy men should be allowed to work 
 in places where there is danger from arsenic, and they should be 
 relieved at regular intervals. Bottles of hydrated oxide of iron, 
 in the form of an emulsion should be kept in readiness, both as a 
 preventative and an antidote. The men must be compelled to 
 exercise the greatest cleanliness, and when exposed to the dust and 
 vapours should cover the mouth with a dry cloth. Arsenical sores 
 
 * Reports of H.M. Inspectors of Mines for the Year 1879, p. 527. 
 
 t " Der Lungenkrebs, die Bergkrankheit in den Schneeberger Gruben." 
 Eulenberg's Vierteljahrsschrift fur gerichtliche Medicin. Neue Folge, xxx. 
 Band, p. 296, Berlin, 1879. 
 
 J Arbeiter-Schutz*, Leipsic, 1879, p. 131. 
 
CONDITION OF THE MINER. 63 7 
 
 should be plastered over with fuller's earth moistened with water 
 and hydrated oxide of iron ; strong drinks, especially brandy, 
 must be avoided, but milk and greasy soups help to resist the 
 poison. 
 
 In an ordinary lead mine, where the ore consists entirely or 
 almost entirely of galena, plumbism is rarely heard of j but 
 when the ore is cerussite, a different state of things arises 
 and the disease may be rife. It is well known that the arti- 
 ficial carbonate, the white lead of commerce, produces poisoning 
 among painters, so much so indeed that one of the ailments due 
 to lead is known as " painters' colic ; " it cannot therefore surprise 
 us, when mere handling is injurious, that breathing a lead-laden 
 atmosphere should likewise be pernicious. Plumbism among 
 miners has probably never been so prevalent as in the Broken 
 Hill district in New South Wales, where some of the ore in the 
 shallow levels is a pulverulent earthy carbonate of lead. According to 
 published accounts,* the state of things must have been very bad in- 
 deed comparatively lately. Miners suffered more than the smelters, 
 but even the ore-pickers were not exempt from the malady. From 
 this fact we may conclude that lead may have entered the system 
 in some cases by eating food with dirty fingers, or, as suggested by 
 the writer of the article alluded to, from smoking a pipe filled with 
 tobacco rubbed in a leady hand. The baneful effects have been 
 reduced by not allowing the men to work very long at one time 
 in the parts of the mine where the soft carbonate occurs. The 
 managers arrange, for instance, that a man shall take one fort- 
 night at mining the earthy cerussite ; the next fortnight he is put 
 to work at the surface and made to quarry the ironstone i.e., the 
 ferruginous outcrop of gossan, which is used as a flux at the 
 smelting works ; and then he takes a fortnight underground 
 in mining the kaolin ore, which consists largely of kaolin and 
 chloride of silver, and has no deleterious effect upon the men, or 
 at all events does not cause lead-poisoning. 
 
 The precautions to be adopted against plumbism at mines of 
 this description are : ample ventilation, laying the dust as far 
 as possible by a spray of water, and the strictest cleanliness. The 
 mine-owner should do his share by giving the men every possible 
 convenience for washing themselves and changing their working 
 clothes, but no amount of forethought on his part will suffice to 
 prevent the evil entirely, if the men fail to avoid every chance of 
 defiling their food or tobacco by lead ore. 
 
 Working in the quicksilver mines is found to be unhealthy, 
 and the men suffer from mercurial poisoning unless special 
 precautions are taken. Thus, at Almaden, even if the ventilation 
 is good, the miner cannot work more than four to four and a half 
 hours a day, nor can he work more than seven or eight days in a 
 
 * " Lead Poisoning," The Australian Mining Standard, vol. vi., 1891, 
 p. 13, and Report of Board of Inquiry at firoken Hill, (Sydney, 1898. 
 
683 OHE AND STONE-MINING. 
 
 month without injuring his health very rapidly.* It is true that 
 the miners suffer less than the smelters, which is the reverse of 
 what happens at Broken Hill, and the explanation of this is that 
 mercurial poisoning is mainly due to the vapour of the metal. At 
 Almaden some of the mercury exists in the native state and is 
 supposed to sublime slowly \ f but even at Idria, where there is 
 no native mercury, where the ore is less rich than at Almaden, 
 and the ventilation excellent, the men work only four hours at a 
 stretch i.e., four hours in the morning and four in the afternoon, 
 with an interval of rest of four hours. 
 
 The symptoms of mercurial poisoning noticed at Almaden are : 
 inflammation of the mouth, salivation and loss of teeth, shiver- 
 ings, gradual and general wasting away. 
 
 Excessive ladder-climbing has long been pointed out by medical 
 men as a cause of disease.^ If the heart is over-stretched day 
 after day and year after year, it becomes dilated, loses some of 
 its contractile power, and is therefore less capable of performing 
 its pumping action properly. The miner who for years has had 
 to descend and ascend by ladders in deep mines, will generally 
 be found to have a feeble heart and weak pulse on this account. 
 Young miners should be careful to avoid the over-exertion caused by 
 climbing with unnecessary haste. In these days of excellent steel 
 wire ropes for winding men up in cages, it is perfectly absurd 
 that a miner should be condemned to the treadmill toil of ladder- 
 climbing, which has nothing to be urged in its favour. The 
 shareholder has to pay for an unprofitable form of labour, his 
 mine is conducted with less supervision than there would be if 
 access to the workings were easier, whilst the unfortunate miner 
 suffers in health and strength. When a mine reaches a depth of 
 TOO yards the owner should introduce means of raising and lower- 
 ing the men mechanically without fatigue. 
 
 It is easy to conceive, when a man is working continuously 
 for years in a constrained position, that certain muscles will be 
 stunted in their growth from want of use, and that others will be 
 abnormally enlarged from over-use, and so cause a distortion of 
 the body. This happens to a slight extent with the men working 
 on the thin bed of copper shale of Mansf eld. 
 
 The disease of the eye known as nystagmus has been noticed 
 among colliers. A person suffering from nystagmus sees objects 
 apparently moving in a circle ; gas lights in a room, for instance, 
 seem to dance ; the man also suffers from headache and giddiness, 
 
 * Kuss, " Note sur 1'etat actnel de la mine et de 1'usine d'Almaden," 
 Annales des Mines, 8me. serie, tome xi. , p. 138. 
 
 t Eng. Min. Jour., vol. xlvi., 1888, p. 435. 
 
 t Dr Peacock, "Medical Report on the Condition ot Miners "; Bankart, 
 " Medical Report on the Condition of Miners in Cornwall and Devon" ; 
 Appendix . to the Beport of the Commissioners appointed to Inquire into the 
 Condition of all Mines in Great Britain to which the Provisions of the Act 
 23 & 24 Viet. cop. 151 do not apply. P. 7 and p. 95, London, 1864. 
 
CONDITION OF THE MINER. 689 
 
 and the eyeballs are noticed to oscillate or rotate. According 
 to Snell * the men most afflicted with nystagmus are those who 
 have to work lying on their side; owing to this unnatural 
 position the muscles of the eyes are unduly strained and suffer 
 from overwork. Mere work upon the side is in some districts 
 insufficient to set up the disease, for during a period of six years 
 only two cases were noticed among the 14,000 Mansfeld copper 
 miners. As these men use open lights, it is not unnatural that 
 nystagmus should have been ascribed by some doctors to the 
 insufficient illumination afforded by the safety lamp. .Snell 
 combats this hypothesis, and cites cases of the disease in persons 
 who have never used a safety lamp; therefore the want of a 
 better light cannot be the only cause. To a layman it seems 
 quite possible that both views may be correct; the two sets of 
 doctors agree that the disease is produced by over-strain of the 
 ocular muscles, and as either of the two causes appears capable 
 of occasioning such a strain, why should there be a difficulty in 
 admitting both explanations ? 
 
 The great heat of the workings on the Comstockf lode has 
 been mentioned in the early part of this chapter, and many men 
 are said to have lost their lives from it, being picked up dead 
 in the mine. New-comers suffered more than the old hands. 
 There was also the danger of falling into scalding water; men 
 fell accidentally into pools of water at a temperature of 157 or 
 158 and perished in great suffering from their skin peeling off. 
 
 In some cases the effect of the hot air on the men is said to 
 have been beneficial, acting like a succession of Turkish baths. 
 When the heat on the Comstock lode first became intense, the 
 miners suffered from pneumonia and rheumatism, because they 
 went out at once into the cold and freezing atmosphere at the 
 top of the shaft, although only a few minutes before they had 
 been in the heated atmosphere of the lower levels. Such sudden 
 changes of temperature were naturally injurious ; and experience 
 soon taught the men and the managers that risks of this kind 
 could not be run with impunity. Good rooms were erected at 
 the tops of the shafts, in which the men could change their 
 clothes, and some were provided with baths. These precautions 
 soon brought about an improvement in the general health of the 
 men. 
 
 In ordinary mining operations, men are rarely subjected to a 
 pressure considerably above that of the surrounding atmosphere ; 
 but as work in compressed air is occasionally necessary, it is 
 well that the student should be reminded of its danger to health. 
 Men who are employed in making foundations for bridges or in 
 driving tunnels, where compressed air is used as a means of 
 
 * Miners' Nystagmus, Bristol, 1892. 
 
 t Lord, " Comstock Mining and Miners." Monographs U.S. Geol. Survey f 
 vol. iv., Washington, 1883, pp. 374 to 399. 
 
 2 Y 
 
690 ORE AND STONE-MINING. 
 
 keeping out water, suffer at times from paralysis and intense 
 pain in the back. These effects of the confinement seem to be 
 mainly felt on coming out into a less dense atmosphere, and may be 
 lessened by prolonging the stay in the air-lock, and so causing the 
 diminution of pressure to be felt gradually. 
 
 5. THRIFT. Remarks upon the condition of the miner 
 would be incomplete without some mention of the following 
 subjects: (i) Provision against loss of pay from sickness acci- 
 dents, strikes, and old age ; (2) Obtaining medical attendance at 
 a small cost ; (3) Procuring supplies of food and clothing upon 
 the most reasonable terms. 
 
 Provident societies are no new thing for the miner ; it has been 
 pointed out by Dr. Wahle, the Director of the Mining Depart- 
 ment at Freiberg, that they date back in Saxony to the 
 fifteenth century, and are as old as mining itself. In this 
 country at the present day three systems are in vogue : clubs 
 for individual mines, general relief societies for large districts, 
 and, lastly, the ordinary friendly societies, not confined to miners, 
 which are resorted to by all classes of workmen. 
 
 In Cornwall and Devon, and in many parts of Wales, there is 
 a club for each mine, and the men agree to a deduction being 
 made from their wages every month for " doctor and club." At 
 many mines the monthly deduction for the doctor is either six- 
 pence, or one shilling, according as he attends the miner only, or 
 his family also.* Under the provisions of the Stannaries Act, 
 1887, some of the old grievances of the Cornishmen have been 
 made to disappear. Each man has a right to choose his own 
 doctor, to whom the amount deducted from his wages is paid. 
 If a surgeon renders himself unpopular by not attending to a 
 case with sufficient care, the men do not select him another time, 
 and his pay and reputation suffer. This check upon the doctors 
 seems to be a sufficient guarantee of the system working smoothly, 
 and to the satisfaction of those most interested in the matter viz., 
 the men themselves. 
 
 The usual deduction for "club" is 6d., and in a few cases gd. 
 per man per month ; the usual " hurt pay " for disablement is 
 is. per day. In the event of a fatal accident the funeral expenses 
 are borne by the mine, and sometimes the sum of 10 is given to 
 the widow or dependent relatives, or a levy of is. per man is 
 made for their benefit. 
 
 The great faults of this system are : First, the want of some 
 provision for widows, orphans, or dependent relatives of persons 
 killed by accidents ; secondly, the fact that a man loses his " hurt 
 pay" and is probably thrown on the parish if the mine in 
 which he had been working is stopped ; thirdly, the want of any 
 
 * Fo&ter and Pike, " Suggestions for the Formation of a Miners' Per- 
 ,manent Club and Etlief Society for Cornwall and Devon," Proc. Min. Inst. 
 Cornwall, vol. i., p. i. 
 
CONDITION OF THE MINER. 691 
 
 provision for ordinary sickness. Of course the first and third 
 objections might be removed by increasing the monthly subscrip- 
 tions, but the second would still remain viz., the uncertainty of 
 the benefits being kept up permanently. 
 
 Far better than the clubs of individual mines are the perma- 
 nent relief societies, of which British miners have reason to be 
 proud. There are now nine of these societies in different parts 
 of England and Wales, and there is also a central society for 
 promoting and watching over their interests and extending their 
 work to new districts.* 
 
 Though started for colliers, these societies include many iron- 
 stone miners and some lead miners and slate quarriers among 
 their members. According to the annual report of the Asso- 
 ciation for 1891, there were 268,971 persons members of 
 these relief societies in the year 1890, whilst the total number 
 employed in and about the mines of the United Kingdom was 
 674,434, inclusive of those employed on private branch railways 
 and tramways, and in washing and coking coal on premises adja- 
 cent to or belonging to the mine. 
 
 The exact nature of one of these societies will be best appre- 
 ciated by examining the rules of the largest, which has done, 
 and is still doing, much excellent work in the North of England. t 
 As it includes the Cleveland ironstone district, although this 
 does not appear from the title, it is specially adapted for my 
 purpose. Its objects are very clearly denned thus : 
 
 " The objects of this Society are the raising of funds by volun- 
 tary subscriptions amongst the members thereof, and by donations 
 from others to make provision in case of fatal and non-fatal 
 accidents as follows : 
 
 " (a) A sum at the death of a member. 
 
 "(&) A weekly allowance to the widow and children of married 
 
 members. 
 " (c) A weekly allowance to members who suffer from non-fatal 
 
 accidents. 
 " (d) An allowance to the parent, or sister, or brother of a deceased 
 
 member during sickness or other infirmity. 
 " (e) Also to make a provision for miners over 60 years of age who are 
 
 permanently unfit to work, the allowance to be paid to be in 
 
 accordance with the contributions received." 
 
 The weekly contribution of each member is 4$., and of a half- 
 member i.e., a boy under 18} only 2 d. Three-eighths of these 
 sums are devoted to the superannuation fund. 
 
 * Central Association for Dealing with Distress caused by Mining 
 Accidents, 3iA, King Street, Wigan ; George L. Campbell, Secretary. 
 
 t Kules of the Northumberland and Durham Miners' Permanent Relief 
 Fund Friendly Society. Established June 7, 1862. Chief Office 
 5, Queen's Square, Newcastle-upon-Tyne. 1892. 
 
 J A boy under 18 but over 16 may be a whole member if he likes ; a 
 boy under 16 can only be a half member. 
 
692 ORE AND STONE MINING. 
 
 The benefits are in the case of 
 
 1. Non-fatal accidents. 
 
 2. Fatal accidents. 
 
 3. Old age. 
 
 If a member is disabled by an accident for more than a week, 
 but not less, he receives the sum of 55. a week or lod. per work- 
 ing day, and a half-member 28. 6d. per week or $d. per day. The 
 payments go on in this way for twenty-six weeks, when, if the 
 person is still disabled, he becomes entitled to the higher relief 
 of Ss. per week, or 45. if he is a half-member, so long as he is 
 unable to work from the effects of the accident. 
 
 In the case of a death by accident, the widow of a married 
 member receives a legacy of ^5, the relatives of an unmarried 
 member receive ^23, and those of a half-member 12. The 
 widow also draws 5$. a week from the funds for the rest of her 
 life, so long as she remains unmarried, and 2s. a week for each 
 child, until the boys are thirteen and the girls fourteen years of 
 age. 
 
 Aged and infirm members over sixty years of age who are 
 certified medically to be unfit to follow their employment receive 
 45. per week ; but the amount of the pension may be reduced if 
 the funds at any time are insufficient to keep up the present 
 allowance. 
 
 During the year 1891 this Society had 113,124 members; the 
 contributions of the members amounted to ^90,169, those of the 
 owners of collieries to ^4860, in addition to which there was an 
 income of ^5208 from invested funds. The following claims 
 were made upon the Society : 
 
 Minor Accidents. 16,500 claims for relief were made; the 
 average length of the period of disablement was about 3^ weeks 
 each. 
 
 Permanent Disablement. 195 claims for accidents that have 
 caused disablement lasting more than 26 weeks; the average 
 duration of each is estimated to be 3 1 years. 
 
 Fatal Accidents. 93 widows came on to the funds. 
 
 Children. 185 children came on to the funds. 
 
 Old Age. 442 new claims for superannuation were made. 
 
 According to the report of the Central Association * the nine 
 societies gave relief for 754 deaths by accidents, and for 39,411 
 cases of disablement during the year 1890. 
 
 We learn from the Reports of Inspectors of Mines that there 
 were 1206 deaths from accidents at all the mines of the United 
 Kingdom in that year, consequently it is evident that a large pro- 
 portion of the victims of these fatalities were insured, and that 
 
 * Central Association for Dealing with Distress Caused by Mining Acci- 
 dents. Report of the Proceedings at the Twelfth Annual Conference, London, 
 1891, Tables VI. and VII., pp. 36-7. 
 
CONDITION OF THE MINER. 693 
 
 their families or dependent relatives received some form of 
 relief. 
 
 Altogether there were 2395 widows and 3496 children receiving 
 benefits from the funds of the nine societies in the year 1890. 
 
 The percentage proportion of the contributions of the colliery 
 owners to those of the ordinary members is less in the Northumber- 
 land and Durham Society than in the others. In 1890 it repre- 
 sented only 5*7 per cent.,* whilst in the Lancashire and Cheshire 
 Society it was 24' i per cent., in the North Wales Society 25*2 per 
 cent., and in the Monmouthshire and South Wales Society 24 per 
 cent. If we turn to Table IX. of the report, the reason of this 
 difference becomes apparent ; it will be seen that all, or a very 
 large number, of the members of these three societies have 
 entered into an agreement with the owners not to bring any 
 claim against them under the Employers' Liability Act of 1880, 
 or, to use the common expression, they have "contracted them- 
 selves out of the Act." They consider that the employer's con- 
 tribution is worth more to them than the chance of occasionally 
 obtaining compensation by proving negligence against him in a 
 court of law. 
 
 Enough has been said to show the present state of the volun- 
 tary system of relief as it now exists in England and Wales ; 
 much of the distress caused by mining accidents is relieved by the 
 nine principal societies, and, in addition, there are numerous 
 smaller societies established for individual mines, having in the 
 main the same objects as the larger ones. 
 
 Something more is needed viz., relief in sickness, and old 
 age pensions for all. Some of the existing clubs of individual 
 mines give sick pay to their members, and there are the ordinary 
 Friendly Societies established on a far firmer basis, which can be 
 resorted to by the miner like any other workman. As far there- 
 fore as sickmss is concerned there is machinery available by 
 which the miner in any part of the kingdom can make the neces- 
 sary provision for himself and his family. 
 
 If he requires a pension, he can get one upon the very best 
 security by going to the nearest Post Office. A young man of 
 twenty can obtain a deferred annuity of 55. a week, commencing 
 at the age of sixty, by paying 2 35. 4^. a year, or lod. a week. 
 If the person wishes to discontinue his insurance, he can do so, 
 and all the money he has paid will be returned to him, provided 
 that an instalment of the annuity has not become due. However, 
 as the facilities afforded by the Post Office have not been utilised 
 to any great extent, compared with the numbers of the working 
 classes, and as a large number of persons spend the last years of 
 their lives and end their days as paupers in the workhouse, it is 
 thought by most people that something more should be done. Great 
 
 * Op. ell. Tables IV. and V., pp. 34-5. 
 
694 ORE AND STONE MINING. 
 
 difference of opinion exists upon the subject; much has been 
 written, and still more said during the last few years, and the 
 controversy has raged mainly upon the question of State aid. 
 The proposals may be summed * up as involving one of the three 
 following principles : 
 
 1. State endowment. 
 
 2. State assistance. 
 
 3. State compulsion. 
 
 1. The first, that of Mr. Charles Booth, means the free gift by 
 the State of a pension of 55. a week to every citizen on attaining 
 the age of sixty-five years. 
 
 2. The best known scheme coming under the second head is 
 that proposed by a Parliamentary Committee,t presided over by 
 Mr. Joseph Chamberlain, M.P. Its main features are as follows : 
 If a young man pays ^5 to the Post Office Savings Bank before 
 the age of twenty -five, he is to be at once credited with ^15 
 more from a State pension fund ; he will then have to pay i a 
 year to the Post Office for forty years, and at sixty-five he will 
 become entitled to a pension of 55. a week. If he dies before the 
 age of sixty-five, there are arrangements for granting a pension 
 to his widow and children. It is also proposed that a male shall 
 be able to purchase a pension of 55. a week on payment of one- 
 half of the sums just mentioned ; but in this case there is no 
 provision for a family. 
 
 3. The last plan of providing old age pensions is that which 
 has been advocated for so many years and with so much skill by 
 the Rev. Canon Blackley. He would compel every one to de- 
 posit with the State, before the age of twenty-one, a sum of about 
 ^10, which would suffice to provide him with a pension of 55. 
 a week on attaining his sixty-fifth year. Canon Blackley points 
 out that in his youth, before marriage, a man would be able to 
 make the proposed saving, and that after this he would no 
 longer be troubled by the thought of not being able to keep up 
 his payments. 
 
 Many arguments may be adduced in favour of each of the 
 three principles of old age pensions, but opinions concerning 
 them must largely depend upon the " personal equation " of the 
 individual that is to say, upon his general views regarding the 
 interference of the State in such matters. 
 
 The Gordian knot of this difficult question has been cut in 
 Germany b;~ the Law of Insurance against Old Age and Infirmity J 
 passed in 1889. Under this law the means for providing the 
 allowances to infirm and aged peraons are made up of eontribu- 
 
 * Reports of the Chief Registrar of Friendly Societies for the Year 1891, 
 London, 1892, p. 26. 
 
 f The Times, London, May 21, 1892. 
 
 Translated in Parliamentary Paper (C, 5827), 1889, price 3^. 
 
CONDITION OF THE MINER. 695 
 
 tions from the State, the employers and the persons insured, the 
 two latter paying like amounts. 
 
 The method of insurance may be briefly described as that of 
 State compulsion with State aid, together with obligatory contri- 
 butions from the employer. This bold experiment will be watched 
 with interest. 
 
 This subject of thrift must not be concluded without a few 
 words about one requisite for the treatment of diseases viz., 
 hospitals. In this country the provision of such institutions is 
 frequently left to private benevolence; in the great tin mining 
 centre of Redruth, for instance, the burden of ensuring accom- 
 modation for the sick and injured has been taken by a charitable 
 owner of mineral property. According to the balance sheets 
 of the institution from 1885 to 1892, he has paid on an average 
 more than 40 per cent, of the total cost, which exceeds ,1300 
 yearly ; the remainder is met by contributions from private per- 
 sons, companies working mines in the neighbourhood and their 
 workmen. 
 
 The Oakeley Hospital at Blaenau Festiniog, which ministers to 
 the ills of some of the quarrymen, was built by the landowner, 
 and is now supported by the largest slate mine. 
 
 Many of the large Continental mines keep up establishments of 
 this kind, and throw them open gratis to their employes. The 
 same plan is adopted by some of the large British companies 
 working mines abroad, and even at Boryslaw, where much of the 
 mining is being carried on in the most primitive manner, a Gali- 
 cian company supports a small hospital, and admits not only its 
 own servants, but also any urgent cases requiring surgical or 
 medical attendance. 
 
 Fortunately, it often happens that a mine has not accidents 
 enough to require the constant use of a hospital and the entire 
 services of a surgeon. This is the case, for instance, at some large 
 mines near Ems ; the company has built a hospital and keeps it in 
 readiness, in case of accidents or sickness, with a doctor on the 
 premises ; but, in consideration of his small stipend, he is allowed 
 to have three rooms at his disposal in which he can treat private 
 patients. In the United States sick and injured miners sometimes 
 go to private hospitals, which are managed by medical men. 
 
 Before complete recovery from an illness or the effects of an 
 accident, a man passes through a period of convalescence, during 
 which he requires little medical aid, but depends for his linal 
 restoration to health mainly upon good food, quiet and regular 
 living, and plenty of fresh air. It is a question in some mining 
 districts whether it is better to support a convalescent home in the 
 locality itself, or to subscribe to one at a distance. The hitter 
 plan is in many cases cheaper, owing to the smaller cost 
 for general expenses ; and at the same time it is better for the 
 patient, who profits by the change of air and scene, which in 
 
696 ORE AND STONE-MINING. 
 
 themselves are powerful remedial agents. In a small island like 
 ours, it is not difficult as a rule for the patient to get to the 
 sea coast without a ruinous expenditure of money in railway 
 fares. At some of the sea-side convalescent homes a miner may 
 be boarded and lodged for three weeks at a total cost of i i6s. ; 
 therefore if a mine is employing 500 men, and each man sub- 
 scribes ^d. per month of four weeks, more than 1$ can be raised 
 annually, or sufficient to give seven invalids a stay of three weeks 
 each at the sea. 
 
 In writing upon the question of thrift, mention must be made of 
 co-operative societies, which give the workman the opportunity of 
 buying his food and clothing at the most reasonable rates. They 
 are so well known nowadays that no description of their advantages 
 is required ; but it is well to point out that their success does not 
 necessarily depend upon their having a very large number of 
 customers, such as could only be expected in a very populous 
 district. Two instances of co-operative societies in the Isle of 
 Man prove this fact, and show that such an institution may 
 prosper commercially, and do good and useful work in a mere 
 village depending upon a mine employing only 200 or 300 
 persons underground. 
 
 6. RECREATION. I am well aware that many will say 
 that in the matter of recreation the mine manager had better 
 not interfere at all ; I do not take this view. Men and boys 
 require diversions of some kind in order to refresh their bodies 
 after toil, and the manager of a large mine often has the oppor- 
 tunity of directing their amusements into the best channels. 
 Tastes differ: some men will find relaxation in reading, and 
 will be glad to be able to borrow books from a library ; others 
 are musical, and will prefer to join a band ; boys, in spite of hard 
 bodily work at the mine, will delight in active games as soon as 
 they are free. As an example of what may be done I will cite the 
 names of the clubs established at the collieries of the Douchy Com- 
 pany in the north of France as recreative institutions : Archers, 
 crossbowmen, gymnasts, philharmonic, and pigeon fanciers. It 
 will be seen from this list that a great many different tastes 
 have been studied in order to encourage the men to employ their 
 spare time in a wholesome manner instead of going to pot-houses, 
 to the injury of their purses, if not to the detriment of their 
 health. 
 
 An example on this side of the Channel may be taken from 
 the extensive collieries in Derbyshire and Nottinghamshire, 
 owned by Colonel Seely, M.P., who has established workmen's 
 clubs, cricket club, football club, pig club, a band, and an annual 
 nower show for the benefit of his men. The cricket ground is 
 one of the best in Derbyshire, and the club-house is a large build- 
 ing containing three billiard-tables, reading and smoking rooms, 
 and a lending library ; the members can obtain any sort of 
 
CONDITION OF THE MINER. 697 
 
 refreshment they like at reasonable prices. The band plays 
 three times a week in the club grounds. In addition, each sepa- 
 rate colliery has its club with a billiard-table, and other appli- 
 ances for recreation. All these institutions are under the control 
 of committees of the workmen, presided over by the General 
 Manager. 
 
698 
 
 CHAPTER XVII. 
 
 ACCIDENTS. 
 
 Death-rate of miners from accidents Relative accident mortality under 
 ground and above ground Fatalities : underground, from falls of 
 roof, from accidents in shafts, from blasting accidents, from under- 
 ground fires, from irruptions of water and sundry other causes 
 Accidents above ground Boiler explosions Non-fatal accidents 
 Ambulance training. 
 
 FEW persons will deny the dangers of the miner's calling ; some, how- 
 ever, consider that the public form an exaggerated idea of these 
 perils from dwelling too much upon occasional colliery explosions. 
 
 Death-rate of Miners from Accidents. In the first place 
 comes the question : What is a dangerous trade ? If we look at 
 the vital statistics quoted from Dr. Ogle in the last chapter, it 
 appears that the majority of miners, thanks, partly, to their 
 starting originally with a more than average good constitution, 
 lead a longer life than many tradesmen in towns. In spite of 
 the diseases and accidents to which he is liable, the average miner 
 is better off than most people would have supposed, before they 
 became acquainted with the figures. On the other hand, if we 
 limit our attention to accidents, we find that the miner gets far 
 more than his share. 
 
 It may be asserted without fear of contradiction that a calling 
 with an annual mortality of i per 1000 from accidents, is 
 hazardous. The statistics concerning accidents in this country 
 are given annually in the statistical summaries prepared by Her 
 Majesty's Inspectors of Mines; and it will be seen from the 
 published figures that, taking all the mines in the United 
 Kingdom and including casualties above and below ground, 
 there was an average annual mortality from accidents of 2*18 
 per 1000 persons employed during the ten years 1873 to 1882 
 inclusive, and that in the next decade the mortality dropped to 
 178 per 1000. 
 
 In this country an accident is classed as fatal if it causes 
 the death of the injured person within a year and a day of 
 the date of the occurrence; it is therefore possible that in 
 certain very rare cases, when more than a year elapses before a 
 man succumbs to his hurts, an accident may be registered as 
 nou-fatal, although it finally turns out to be fatal. Cases of 
 
ACCIDENTS. 
 
 699 
 
 this kind are so few that the correctness of the British statistics 
 cannot be appreciably affected by them. 
 
 In an interesting report upon the Exhibition held in Berlin in 
 1889 of appliances for the prevention of accidents, M. Paul 
 Habets gives a careful summary of the progress realised in 
 Belgium, France, Great Britain, and Prussia.* He divides his 
 results into periods of ten years : 
 
 TABLE I. 
 Annual Death-rate from Accidents per 1000 Persons Employed, 
 
 Period. 
 
 Belgium. 
 
 France. 
 
 Great Britain. 
 
 Prussia. 
 
 1851 to i860 
 
 2-97 
 
 3-40* 
 
 4-07 
 
 4"9lt 
 
 1861 to 1870 
 
 2'6o 
 
 2-96 
 
 3'3 2 
 
 6'33 
 
 1871 to 1880 
 
 2'45 
 
 2'2I 
 
 2 '35 
 
 4-90 
 
 1880 to 1888 
 
 2-13 
 
 i-57 
 
 1-94 
 
 2-96 
 
 * 1853 to 1860. 
 
 t 1852 to 1860. 
 
 These figures show a steady diminution in the number of 
 accidents excepting in Germany, for in the decade 1861 to 1870 
 the mortality was terrible ; but even the most favourable averages 
 are far above the standard of i per 1000, which has been assumed 
 as the mortality ratio of a dangerous occupation. 
 
 Relative Accident Mortality amongst Underground and 
 Above ground Workers. Descending into details, let us 
 examine how the two classes of mines viz., those under the Coal 
 and those under the Metalliferous Act compare with one another. 
 The figures will be made most plain by putting them in a tabular 
 form. 
 
 TABLE II. 
 
 Decennial 
 Period. 
 
 Average Number of 
 Persons Kmployed 
 Underground 
 and Above-ground 
 Annually. 
 
 Total Number of 
 Lives lost by 
 Aociuents in the 
 Decennial 
 Period. 
 
 Average Annual Death- 
 rate from Accidents 
 per 1000 Persons 
 Employed. 
 
 Mine 
 
 1873 to J 882 
 1883 to 1892 
 
 5 classed under the ( 
 503,428 
 571,719 
 
 3oal Mines Regula 
 
 11,294 
 10,327 
 
 tion Act. 
 
 2-243 
 I -806 
 
 Mines da 
 
 1873 to 1882 
 1883 to 1892 
 
 ssed under the Mete 
 
 55,388 
 42,481 
 
 illiferous Mines R 
 
 909 
 612 
 
 'gulation Act. 
 
 1-641 
 1-440 
 
 According to these figures, work at mines under the Coal Mines 
 
 * "Les Accidents dans les Mines et 1'Exposition Generale Allemande 
 pour la Protection centre les Accidents (Berlin, 1889)." Revue Universelle 
 dcs Mines, 3 aerie, t. ix. et xi., 34 annee, 1890. 
 
7 oo 
 
 ORE AND STONE-MINING. 
 
 Act presents decidedly more perils than work at mines under the 
 Metalliferous Act. Speaking roughly, the relative degrees of 
 danger were as 1 1 to 8 in the first period and 9 to 7 in the second. 
 In order to make the comparison of any real value, it is neces- 
 sary to go somewhat further. Owing to the amount of labour 
 required for " dressing," the proportion of surface hands is much 
 larger at a tin, copper, lead, or slate mine, than at a colliery. In 
 round numbers about one-fifth of the persons employed at mines 
 under the Coal Mines Regulation Act work above ground, and four- 
 fifths underground ; at mines under the Metalliferous Mines Act 
 the proportions are two-fifths above ground, and three-fifths under- 
 ground. Consequently, as the proportion of the surface hands 
 with a small risk is twice as great in one case as in the other, it is 
 impossible properly to compare the risks of the underground 
 workers until this source of error has been eliminated. The 
 death-rates calculated separately are as follows : 
 
 TABLE III. 
 
 Average Annual Death-rate from Accidents per 1000 Persons 
 employed in and about the Mines of the United Kingdom of 
 Great Britain and Ireland. 
 
 Decennial Period. 
 
 Below Ground 
 
 Above Ground. 
 
 Coal Mines 
 Act. 
 
 Metalliferous 
 Mines Act. 
 
 Coal Mines 
 Act. 
 
 Metalliferous 
 Mines Act. 
 
 1873 to 1882 . 
 1883 to 1892 . 
 
 2-572 
 2-009 
 
 2-348 
 2-145 
 
 0-919 
 0-959 
 
 0-578 
 0-392 
 
 In the first period the relative amounts of danger to under- 
 ground workers were as 51 to 47, a very different proportion 
 from 1 1 to 8 as appeared from the other table ; in the second 
 period the mines under the Coal Mines Act have the advantage, 
 whereas by the original table they seem to be more dangerous 
 than those under the Metalliferous Act. 
 
 The necessity for considering the underground death-rate 
 separately, when inquiring into the relative amounts of danger at 
 different classes of mines is well illustrated in the case of the 
 underground slate quarries of North Wales. These appear to be 
 less dangerous than collieries, or more dangerous according as 
 the surface hands are included or not in the calculations. Taking 
 the ten years 1875 to 1884, the annual death-rate from accidents 
 at the underground slate quarries was 2*07 per 1000 among all 
 the workers as a whole, and 3*2 per 1000 among the under- 
 ground workers taken separately. The former rate is better than 
 the corresponding 2-243 (Table II.) of mines under the Coal Mines 
 
ACCIDENTS. 701 
 
 Act, and the latter is worse than 2*572 (Table III.). Conse- 
 quently the average underground slate-quarrier has a more 
 perilous calling than the average collier. 
 
 While correcting one misapprehension I must guard against 
 another, and point out that the Coal Mines Regulation Act applies 
 to mines of coal, stratified ironstone, shale, and fireclay. Therefore 
 the figures given do not refer solely to coal-mines, and do not re- 
 present precisely the risks of the collier, and it becomes necessary 
 to examine whether the introduction of certain disturbing 
 elements affects the average risk to any great extent or not. 
 Compared with coal, the amounts of fireclay, ironstone, and 
 shale are small, and the total quantity of these minerals raised 
 in 1893 was less than 6 per cent, of the weight of the coal ; any 
 error caused by the introduction of ironstone and other mines, is 
 likely therefore to be inconsiderable. After coal, the most 
 important mineral wrought under the Coal Mines Act is ironstone, 
 and more than half the total quantity raised is obtained in the 
 Cleveland district. From the figures given in the reports of the 
 inspectors of mines, I find that from 1873 to 1882 there were 183 
 deaths from accidents underground in the Cleveland district, 
 with an average annual underground staff of 6863 persons, con- 
 sequently the average death-rate was 2 '66 per 1000; in the 
 following decennial period it was 2'2i per 1000.* Both these 
 proportions are higher than the corresponding ratios calculated 
 for the whole of the mines under the Coal Mines Act ; therefore 
 if all disturbing factors were eliminated, we may fairly assume 
 that the average underground death-rate at the coal-mines proper 
 did not exceed the figures given in Table III. 
 
 On the other hand, I must remark that the Metalliferous Mines 
 Regulation Act applies to all mines not included under the Coal 
 Mines Act, and the statistics under the former Act refer not only 
 to mines worked for ores, but also to salt-mines and underground 
 slate and stone quarries. The figures quoted cannot be taken as 
 relating solely to true metalliferous mines. 
 
 For the sake of comparison I have extracted from the annual 
 reports of the inspectors of mines, the figures for the metalliferous 
 mining district of Cornwall and Devon, including also a few 
 mines in Somersetshire and Dorsetshire. During the ten 
 years 1873 to 1882 there were 280 deaths from accidents under- 
 ground, with an average underground staff of 10,629 persons. 
 This means an average annual death-rate among the underground 
 workers of 2*63 per 1000. The corresponding figure for the ten 
 years 1883 to 1892 was found to have been 2-54 per 1000. 
 
 The conclusions arrived at from these statistics are, first, that 
 
 * From 1873 to 1883 the published statistics refer to the whole of the 
 North Riding of Yorkhhire, where a little coal is worked, but not in suffi- 
 cient quantity to affect the ratios perceptibly ; since 1883 the Cleveland 
 figures have been kept entirely separate. 
 
702 ORE AND STONE-MINING. 
 
 tha mines under the Coal Mines Regulation Act are not always 
 more destructive of life than the mines under the Metalliferous 
 Mines Regulation Act ; and secondly, that certain mines worked for 
 metallic ores, such as the iron mines of Yorkshire, and the tin and 
 copper mines of Cornwall and Devon, present more dangers to the 
 underground worker than an average colliery, in spite of the 
 almost complete absence of explosions of gas. In other words, as 
 has been pointed out repeatedly, fire-damp is not the worst enemy 
 the miner has to contend with. It is very evident also that if 
 different classes of mines are to be compared as regards dangers, 
 the figures must be restricted to those working below ground ; and it 
 is to be regretted that some of the official reports concerning mines 
 in other countries afford no means of making the proper compa- 
 rison. On the other hand, foreigners sometimes com plain that our 
 British statistics do not give them the true coal-mining accidents 
 separately ; but when the two minerals, coal and ironstone, are 
 being worked in the same pit, and when the preliminary and 
 exploratory work is common to both minerals, it is impossible to 
 draw any strict line of division. 
 
 Classification of Accidents. In order to obtain some general 
 ideas concerning the kinds of accidents which occur at mines we 
 must begin by classifying them. The basis of such a classification 
 may be either the place where the accident happened, or the 
 cause of the occurrence. Usually the classification is founded 
 upon both. 
 
 Following the plan which was adopted in the early days of 
 mine inspection in this country, the British classification begins 
 by separating the accidents which happened underground from 
 those which took place at the surface, and then the underground 
 accidents are arranged under the four main heads : 
 
 Explosions of fire-damp or coal-dust. 
 Falls of ground. 
 In shafts. 
 Miscellaneous. 
 
 The classification is not strictly logical, because it to a certain 
 extent mixes up cause and place ; there may be explosions of fire- 
 damp or falls of ground in shafts, but these would naturally be 
 placed under the headings which most particularly describe them, 
 so that the heading " in shafts " does not always include every 
 accident which has happened there. However, the classification 
 has been used so long, and is so well understood, that it would be 
 absurd to make any great alteration now. 
 
 The relative importance of each of these classes is brought out 
 by the following table, which has been calculated for the same 
 periods as the preceding one : 
 
ACCIDENTS. 
 TABLE IV. 
 
 703 
 
 
 All the 
 Mines in the 
 United King- 
 dom under 
 the Coal 
 Mines Regu- 
 lation Act. 
 
 All the 
 Mines in the 
 United King- 
 dora under 
 the Metal- 
 liferous Mines 
 Regulation 
 Act. 
 
 Stratified 
 Ironstone 
 Mines of the 
 Cleveland 
 District. 
 
 Tin, Copper, 
 &c., Mines of 
 Cornwall, 
 Devon, Dor- 
 set, and 
 part of 
 Somerset. 
 
 Kind of Accident. 
 
 
 
 
 
 
 1.4 
 
 * 
 
 S 
 
 o 
 
 S5 
 
 "o 
 
 &g! 
 
 8 
 
 
 'ill 
 
 
 25 J 
 
 11 
 
 ||| 
 
 &i 
 
 
 If 
 
 
 Q 
 
 I* 
 
 *ll 
 
 ~cH 
 
 ^fi" 
 
 ^H 
 
 fi|| 
 
 "gc- 
 
 
 lo"i 
 
 5 2 
 
 if! 
 
 ii 
 
 lot, 
 
 II 
 
 
 
 
 H - 
 
 P V 
 
 H * 
 
 A 
 
 H ^ 
 
 OH 
 
 H rf 
 
 
 
 TEN YEARS 1873 TO 1882 INCLUSIVE. 
 
 /Explosions of 
 
 
 
 
 
 
 
 
 
 ^ fire-damp 
 
 2629 
 
 3 3'3 
 
 
 
 
 
 4 
 
 2'0 
 
 
 
 
 
 g - Falls of ground 
 
 4534 
 
 40- 1 
 
 3M 
 
 34'4 
 
 92 
 
 447 
 
 85 
 
 2.S-S 
 
 pq 2 In shafts . 
 
 I 33 
 
 ITS 
 
 241 
 
 26", 
 
 12 
 
 5*8 
 
 107 
 
 32-0 
 
 v Miscellaneous . 
 
 1907 
 
 I7-0 
 
 227 
 
 25-0 
 
 75 
 
 36-4 
 
 88 
 
 26-1 
 
 Above ground . 
 
 921 
 
 8-1 
 
 128 
 
 14-1 
 
 2 3 
 
 in 
 
 54 
 
 16-2 
 
 Totals . 
 
 11294 
 
 IOO 
 
 909 
 
 IOO 
 
 206 
 
 IOO 
 
 334 
 
 IOO 
 
 TEN YEARS 1883 TO 1892 INCLUSIVE. 
 
 {Explosions of 
 
 
 
 
 
 
 
 
 
 fire-damp 
 Falls of ground 
 In shafts . 
 
 1469 
 4602 
 878 
 
 14-2 
 44-6 
 8-s 
 
 6 
 238 
 132 
 
 1 l 
 21-6 
 
 83 
 
 2 
 
 I "5 
 
 4S 
 76 
 
 21-8 
 
 Miscellaneous . 
 
 23 1 6 
 
 22-4 
 
 169 
 
 27 6| 
 
 32 
 
 24-4 
 
 61 
 
 29-6 
 
 Above ground . 
 
 1062 
 
 10-3 
 
 67 
 
 10-9 
 
 14 
 
 107 
 
 24 
 
 117 
 
 Totals . 
 
 10327 
 
 IOO 
 
 612 
 
 IOO 
 
 3. 
 
 IOO 
 
 206 
 
 IOO 
 
 The further subdivision adopted in this country for classifying 
 is given in the table below : 
 
704 
 
 ORE AND STONE-MINING. 
 
 UNDERGROUND, 
 
 IN SHAFTS 
 
 ^MISCELLANEOUS. 
 
 ON SURFACE 
 
 TABLE V. 
 Classification of Accidents. 
 
 EXPLOSIONS OP FIRE-DAMP OR COAL-DUST. 
 
 FALLS OF GROUND, j Falls of of - 
 ( >i > siae. 
 / Overwinding. 
 Ropes and chains breaking. 
 Whilst ascending or descending by 
 
 machinery. 
 
 Falling into shafts from surface. 
 Things falling from surface. 
 Falling from part way down. 
 Things falling from part way down. 
 ^ Miscellaneous in shafts. 
 f Explosions of gunpowder, &c. 
 Suffocation by gases. 
 Irruptions of water. 
 Falling into water. 
 On inclined planes. 
 By trams and tubs. 
 By machinery underground. 
 Sundries underground. 
 ( By machinery on surface. 
 1 Boilers bursting. 
 1 On railways and tramways. 
 ( Miscellaneous on surface. 
 
 Explosions of Fire-Damp or Coal-Dust. With few excep- 
 tions, fatalities from explosions of fire-damp in this country are 
 confined to coal mines. 
 
 Falls of Ground. Table IY. indicates plainly what point 
 requires the special attention of the mine-owner, in his endeavours 
 to ward off the dangers which threaten his workmen. By far the 
 largest proportion of fatalities occur from falls of ground; and the 
 same story is told by the statistics of other countries. Without 
 attempting to refer to all the information which is published on 
 the subject, it will suffice to say that 36 per cent, of the deaths at 
 Prussian* coal mines in 1891, and 47 per cent, of those at the ore 
 mines, are ascribed to this cause. This cannot be a matter of 
 surprise when we consider the conditions under which the miner 
 carries on his labour : in the overhand stopes of an ore mine, he is 
 constantly taking down the roof above his head ; in working away a 
 stratified deposit, he is continually pushing forward under a fresh 
 part of the overlying stratum, which may have concealed and un- 
 suspected joints ; at other times, he is engaged in removing from 
 the parent bed huge masses of rock weighing many tons each ; 
 no wonder, therefore, that he is occasionally caught by a fall. 
 
 These accidents are best guarded against by incessant watchful- 
 ness on the part of the men nd masters, by putting in supports, 
 even when they do not appear immediately necessary, and by 
 
 * Zeitschr. f. B.-H.-u. S.-Wesen, rol. xl., 1892, p. 32. 
 
ACCIDENTS. 705 
 
 regulations defining how closely props shall be set. Testing the 
 ground by " sounding" i.e., by striking it with the hammer and 
 noticing the sound emitted often enables the workman to detect 
 whether the rock is firm or not ; but the indication is not always 
 reliable. If the mass of rock is large, it may " sound " all right, 
 and yet not be firmly attached as supposed. Besides, ground 
 which is perfectly firm and safe when first laid bare by the miner, 
 will often lose its stability with the lapse of time. Air and mois- 
 ture penetrating into the minute concealed joints and acting for 
 months or years have the effect of gradually loosening the adher- 
 ence of the rock masses ; the constant shaking produced by 
 blasting, to say nothing of minute but oft-repeated earth tremors, 
 are all acting in the same way, and therefore the miner has no 
 right to conclude that places which were safe originally are going 
 to continue so for ever. 
 
 Shaft Accidents. The principal dangers that beset the 
 miner in shafts are manifest from the different headings, and 
 many of the means of guarding against them have already 
 been explained in the chapters upon winding and descent and 
 ascent. It must not be supposed that all the accidents classified 
 xmder the third heading in the British statistics occurred during 
 the ordinary times of going up and down ; this division also 
 includes fatalities which took place while men were occupied in 
 making repairs, or were using machinery not intended for the 
 purpose of raising men. The German official statistics contain 
 a table in which these irregular ascents or descents are eliminated, 
 and make it possible to institute a comparison between the relative 
 degrees of safety of the different methods of obtaining access 
 to the workings. Judging by the result of the ten years 1881 
 to 1890, the death-rate from accidents per 1000 persons was 
 o - o6o with the cage, 0*066 with ladders, and 0*196 with the man- 
 engine ; this last contrivance is therefore far more dangerous than 
 the cage or ladders, although the list of man-engine fatalities was 
 not swollen by any big catastrophe, such as happened in the 
 previous decennial period. A distinction must be made between the 
 single-rod and the double-rod machines, and the Prussian statistics 
 include many of the latter. It will be readily understood that 
 a fall in a naked shaft with few fixed platforms is far more likely 
 to be fatal than a fall in the shaft of a single-rod machine, which 
 is closed completely with the exception of the small manholes 
 at intervals of 1 2 feet. As far as I am aware, no accident on a 
 single-rod man-engine in Cornwall, even when a rod has broken 
 with men on it, has ever caused more than one death ; but there 
 are two bad cases on record with double-rod engines in Germany. 
 
 In the year 1 880 eleven men met with their death at Abraham 
 mine near Freiberg by being precipitated down the shaft when one 
 of the rods broke while they were " riding " upon it. It appeared 
 from the official inquiry that the timber rod had become rotten, 
 
 2 Y 
 
706 ORE AND STONE-MINING. 
 
 and that it ought to have been changed long before the accident. 
 The other bad fatality was at Rosenhof shaft near Clausthal in the 
 Hartz, where again eleven poor miners were suddenly killed from 
 a similar breakage. These two accidents prove the incorrectness 
 of the statement made by those who extol the man-engine at the 
 expense of the cage, and say that no accident can happen with the 
 former except through the miner's own carelessness ; but when 
 making any such comparison it is essential to know precisely 
 which kind of man-engine is meant. Thus if we take the case of 
 Cornwall, where the double-rod machine no longer exists, we find 
 just the reverse of what appears in Prussia. The death-rate from 
 accidents on man-engines in Cornwall and Devon during the seven 
 years 1873 to 1879 * was 0*14 per 1000 persons using them, whilst 
 the annual death-rate per 1000 persons using ladders was higher 
 viz., 0*21. If the actual distance travelled had been taken into 
 account, the scale would turn more decidedly in favour of the 
 man-engine. 
 
 In the Prussian figures just quoted, the ladder appears but 
 little more dangerous than the cage ; probably most of the mines 
 provided with ladders are much shallower than those fitted with 
 cages, so that if the men had been obliged to ascend from equal 
 depths in both classes of mines, the list of ladder accidents 
 would no doubt have been largely increased. 
 
 The Belgian machines, called warocqueres after their con- 
 structor, are rendered safer than the Hartz or Saxon man- 
 engines by having a railing round the back of each platform 
 on the rods. Some of the double-rod machines are made with 
 large platforms, so that two persons can stand on them. 
 
 Miscellaneous Accidents Underground. Explosions of 
 Gunpowder, &c. Blasting accidents, which head this class, are 
 possibly less numerous than many people would suppose, when 
 reflecting upon the large quantities of gunpowder and other more 
 powerful explosives which are annually consumed by the miner. 
 
 They occur in many ways : 
 
 a. Accidental ignition of powder, while carrying it or handling 
 it, from a spark of the candle. 
 
 b. Getting in the way of blasts, either from not retiring to a 
 safe place, or from a hang-fire of the fuse, or from erroneously 
 supposing that a fuse had not been ignited by the "snuff." 
 
 c. Ignition of the charge during the operation of tamping. 
 Sometimes, no doubt, a spark is struck by an iron rammer and 
 communicates fire to the charge by a train of powder lying either 
 behind the fuse or in ragged portions of a hole bored in " vuggy " 
 ground; in other cas-~s it is thought that just as German 
 tinder can be ignited by the mere compression of air, so the 
 
 * Report* of H.M. Inspectors of Mines for the Year 1879, London, 1880, 
 p. 425. 
 
ACCIDENTS. 707 
 
 charge itself may be fired by hard ramming at the commence- 
 ment. The number of accidents of this class has been reduced 
 by the introduction of the nitroglycerine explosives, which will 
 exert their useful effect without hard tamping. 
 
 d. Illegally boring out or picking out the tamping of holes 
 which have missed fire. 
 
 e. Exudation of nitroglycerine from dynamite left exposed to 
 water in a hole which has missed fire. The sensitive oil may explode 
 when the adjacent rock is struck by the pick or drill. 
 
 f. Unexploded remnants of dynamite or gun-cotton. It occa- 
 sionally happens that the whole of a charge of one of the 
 nitroglycerine or pyroxyline explosives does not go off com- 
 pletely : after firing a shot the miner may find that the blast 
 has not rent the rock to the bottom of the hole, but has left a 
 "socket"; to save himself a few inches of boring, he sometimes 
 is tempted to use this in starting the next hole. Such proceed- 
 ings have been proved to be most dangerous, for the blows of 
 the steel tool may fire the unexploded remnants, and cause a 
 serious disaster. 
 
 g. Miners, and indeed others, have been injured by the 
 explosion of the fulminate of mercury in the detonators?, or caps, 
 when examining them incautiously, or while endeavouring to pick 
 out sawdust with which they were choked. 
 
 The golden rule is to treat explosives as substances which will 
 and do explode, but it is naturally difficult for the miner who is 
 handling them day after day not to become somewhat callous to 
 their dangers. 
 
 Suffocation by Gases. Few fatalities in this country are put 
 down to suffocation by gases given off naturally by the rocks. 
 
 Irruptions of Water. Irruptions of water into mines happen 
 in three ways : 
 
 Floods at the surface due to an unprecedented rainfall. 
 
 Extending the workings too close to the bottom of the sea or a river. 
 
 Breaking into old workings full of water. 
 
 All these causes have occasioned disasters in mines. The first 
 danger may be avoided by keeping the top of every shaft of the 
 mine well above the level of the lowest land of the district. If 
 it happens that the only convenient site for a shaft is near the 
 bottom of a valley, the top may be built up with masonry strong 
 enough to resist a flood. Many lives were lost in Hungary in 
 May 1892, from the bursting of a waterspout, which caused water 
 to pour clown some mine shafts. 
 
 Breaking into the flooded workings of old adjacent mines may 
 happen through want of knowledge or want of care. Defective 
 plans are one source of the irruptions, the miner being beguiled 
 into a false security by inaccurate surveys of the adjacent property, 
 or by ignorance that any workings had ever been made there before. 
 
;o8 OEE AND STONE-MINING. 
 
 The Coal Mines Act enjoins the precautions which are well known 
 to every miner in approaching old workings viz., boring holes in 
 advance for the purpose of tapping the water, before there is any 
 danger of the protecting partition giving way under the pressure 
 behind it. The water can then be drained off slowly, and the 
 partition need not be broken down until all chance of flooding is 
 past. 
 
 On Inclined Planes. Accidents may happen from men being 
 caught and knocked over by waggons, while they are making use 
 of inclines as travelling roads ; the statutory manholes or refuge 
 niches are designed to prevent dangers of this kind, but a better 
 plan is to provide independent walking roads, or to partition off 
 the walking road from the railroad. At some mines the men are 
 prohibited from walking upon the inclines while trucks are being 
 drawn up and down, and work is stopped at the changes of the 
 shifts, in order to give them the means of descending and 
 ascending in safety. 
 
 By Trams and Tubs. It would be strange if men were not 
 sometimes injured when moving tram waggons. Owing to an 
 imperfection in the road, a waggon may turn over and catch a 
 man in its fall, or in narrow levels a man may be nipped against 
 the side. 
 
 By Machinery Underground. Proper fences will prevent some 
 of the fatalities from machinery underground, and such safeguards 
 become all the more necessary in the dark or ill-lighted passages 
 of a mine, where one may have to assume a cramped position in 
 going past the moving mechanism. 
 
 Sundries Underground. Under this heading will be found 
 various accidents which cannot be placed in one of the other sub- 
 divisions. The most serious are underground fires ; in fact, two of 
 the worst catastrophes known in mining have happened from this 
 cause; they are barely equalled by the worst explosions in collieries, 
 and go to prove a fact already insisted on viz., that coal mining 
 is not the most perilous form of underground labour. I refer 
 now to the underground fires at De Beers diamond mine and at 
 Pribram. In the year 1888 some of the timber in one of the 
 shafts at De Beers accidentally took fire, the flames spread rapidly 
 and soon filled the mine with smoke to such an extent that 
 twenty-four white men and 200 natives were suffocated. The 
 Pribram disaster of May 1892, was on an even larger scale. 
 Again, some accident or carelessness caused the ignition of the 
 timber in one of the shafts, and the burning wood produced 
 such fumes that 318* persons were asphyxiated in the mine, whilst 
 one died a few days after his rescue. 
 
 These are not the only cases of great disasters arising from fires. 
 
 * " Der Grubenbrand in Pribram am 31 Mai 1892,'' B. u. 7i. Z.^ 1893, 
 
 p. 212. 
 
ACCIDENTS. 709 
 
 At the Mauricewood Colliery,* in 1889, sixty-three out of sixty- 
 live men who were in the mine lost their lives through an under- 
 ground fire, the cause of which was never precisely ascertained ; 
 possibly a naked light carried on the head of one of the men came 
 in contact with the very dry timbering on an incline or with some 
 brattice cloth, and set it on fire. The accident was in no way due to 
 the fact that the mineral worked was coal. Turning to ore mines, 
 we find, for instance, that fires have happened on more than one 
 occasion in the workings on the Comstock lode. Before the year 
 1869 they fortunately had no other evil effect than driving the 
 men out of the workings ; but in April of that year a fire broke out 
 in the 8oo-foot level of the Yellow Jack mine, possibly from a candle 
 left near the timber, and it burnt along unnoticed until at last 
 a " stull " gave way and drove a blast of foul air and smoke into 
 the shafts. This happened at the change of shifts and thirty-four 
 miners were suffocated.t After unsuccessful attempts to rescue 
 the men, and when all hope of their being alive had been abandoned, 
 steam was forced into the mine two days after the accident for 
 seventy-two hours. This proved insufficient, and steam was again 
 forced in for two days. The fire was not completely subdued for 
 several weeks, arid even six months after the accident, smouldering 
 timber was sometimes met with. According to the experience 
 gained in this accident, steam is not effectual in extinguishing a 
 mine fire, though it is useful as a temporary expedient for purify- 
 ing the atmosphere of the mine and checking the flames, and so 
 rendering it possible to put in dams and cut off the supply of 
 oxygen to the conflagration. 
 
 In addition to the big catastrophe, there were several minor 
 accidents of a like nature, and forty-nine persons in all lost their 
 lives from underground fires at mines on the Comstock lode in 
 seventeen years 
 
 A fire at the Calumet and Hecla copper mines on Lake 
 Superior in November 1888 claimed eight victims, and in addition 
 to this loss of life caused a considerable loss of money. Judging 
 by the accounts which are published from time to time in the 
 mining newspapers, underground fires are not so uncommon in ore 
 mines as one might suppose, and it may often depend upon a mere 
 chance whether they become fatal to life or not. With a mineral 
 so easily ignited as native sulphur, the occurrence of fires in the 
 Sicilian mines will not excite astonishment ; some of the accidents 
 arise from carelessness with lamps and in blasting, but the most 
 common cause is the heat generated by the friction of heavy 
 
 * Johnston and Bell, " Mauricewood Colliery, Report to the Secretary 
 of State for the Home Department," Edinburgh, 1890. 
 
 f- Lord, " Comstock Mines and Miners," Monographs U.S. Geol. Survey 
 vol. iv., Washington, 1883, p. 269. 
 
 J Op. cit., p. 404. 
 
 Rtoista del Servizio Mincrario net 1888, Florence, 1890 p. 70. 
 
7 io ORE AND STONE-MINING. 
 
 masses of the sulphur -bearing rock when there are falls, which, as 
 has already been stated (Chapter VI.), are sometimes the result of 
 the method of working adopted. Many of the fires last for a 
 very long time, and in one instance sixty years elapsed before the 
 burning rock was extinguished. The number of accidents from 
 suffocation by sulphurous acid produced by underground fires at 
 the Sicilian mines is by no means small; thirty-five persons 
 perished in this way during the five years 1884 to 1888, to say 
 nothing of four deaths from inhaling carbonic acid gas, and 
 thirteen deaths from sulphuretted hydrogen.* 
 
 The moral to be drawn from these unfortunate accidents is that 
 at all events the main shafts, or other approaches to the under- 
 ground workings, should be constructed in a manner calculated to 
 prevent a repetition of such great disasters. Many of the shafts 
 in mines, especially those devoted to pumping, are so wet that 
 there is no fear of a fire even if they are lined with timber ; in 
 others the lining is of brickwork or masonry, and the guides are 
 made of steel rails or wire ropes ; the shaft is therefore uninflam- 
 mable. In very dry mines, on the other hand, the danger does 
 exist of the shaft being converted by some slight carelessness, or 
 by an accident with a lamp, into a huge blazing furnace, which 
 may send clouds of suffocating fumes into the workings and pre- 
 vent the exit of the miners or the entry of rescuers. To guard 
 against such a state of things, either timber linings may be 
 eschewed and replaced by incombustible linings, or the inflam- 
 mability of the wood may be reduced by keeping it damp. As 
 already pointed out, water is in some cases made to trickle over 
 the shaft timber in order to prevent its being attacked by 
 dry rot. 
 
 I have dwelt somewhat at length upon these fatalities from 
 fires, because of the very serious consequences which have resulted 
 from them in recent years. 
 
 Before passing on to the accidents which happen at the surface, 
 it may be well to call attention to two recent rescues of entombed 
 miners, as instances of the length of time men can exist without 
 food, so that in case of the accidental imprisonment efforts to 
 recover the sufferers may not be relaxed too soon. In July 1892 
 three miners were shut in by a fall at a brown-coal mine in 
 Bohemia, and were rescued after the lapse of no less than seventeen 
 days, during the whole of which time they were deprived of food, 
 though sufiiciently supplied with drinking water. A shade more 
 wonderful is the escape of four men at Jeansville in Pennsylvania,! 
 in February 1891. Seventeen persons were shut in by the irrup- 
 tion of water into the mine from adjoining workings, and they 
 could not be reached until the level of the water had been lowered 
 by pumping. When the rescuers were able to penetrate into the 
 
 * Op. dt., p. 54. 
 
 f Eng. Min, Jour., vol. li. 1891, p. 447. 
 
ACCIDENTS. 711 
 
 workings, eighteen days after the disaster, four of the seventeen 
 men were found alive, though of course extremely weak. 
 
 Accidents on the Surface. By Machinery. A very large 
 proportion of the surface accidents are such as might happen at 
 any factory. Though they cannot be prevented entirely, for men 
 and boys will sometimes go into the most unexpected places, much 
 good can be done by fencing ; and it is always well to err upon 
 the side of over-caution, and protect shafting or other moving 
 parts which may at first sight seem quite innocent. If the 
 lubricant cannot be supplied by one of the constant feeders, the 
 attendant should do the oiling, as far as possible, when the 
 machinery is stopped for meal-times or for some other purpose ; 
 the desirability of wearing tightly fitting clothes has already been 
 mentioned, and it is always advisable to have the means of 
 throwing machinery out of gear quickly, in case a person is caught 
 by it. 
 
 For putting belts on to pulleys, a special "shipper" is safer thafi 
 the hand. 
 
 Now that so many mines have circular saws, it is well to 
 recollect that the use of a guard, like the Lakeman guard for 
 instance, may occasionally save a man the loss of a finger or a 
 hand. 
 
 Looking at the fact that millions of slates that are made annually 
 by machines with revolving or guillotine-like knives, it is not strange 
 that through momentary inadvertence men should now and then 
 put the hand in a little too far and lose the end of a finger. It is 
 impossible for any mortal to be continually on the watch against 
 such occurrences as these, hour after hour and day after day, and 
 the marvel really is that in spite of distractions the human machine 
 works as correctly as it does. 
 
 Boiler Explosions. The subject of boiler explosions concerns 
 the general manufacturer quite as much as it does the miner, 
 and it has been so thoroughly studied of late years that there 
 is no longer any reason for ascribing such occurrences to mys- 
 terious and inexplicable causes. Boilers burst from weakness, 
 which may be due to original malconstruction, to improper 
 treatment, or to ordinary wear and tear. It is very desirable 
 that every boiler should be cleaned out at least once in three months 
 and then carefully examined internally, a record being kept at the 
 office signed by the person making the inspection. In England, 
 very many owners of boilers join such a society as the Manchester 
 Steam Users Association and have their boilers periodically 
 inspected by competent experts, who at the same time are able 
 to give many valuable hints concerning safe and economical 
 methods of working. 
 
 Miscellaneous on Surface. Under this last heading are included 
 a variety of accidents, which need no special mention. 
 
 It would be interesting to know the exact number of accidents 
 
712 
 
 ORE AND STONE-MINING. 
 
 FIG. 709. 
 
 which happen at open works, but unfortunately no official figures 
 are published showing death-rates for the whole Kingdom, such 
 AS are calculated in the case of true underground mining. 
 Judging by certain returns lately published,* it seems that some 
 open quarries are decidedly more dangerous than the average mine. 
 Non-fatal Accidents. Statistics concerning non -fatal acci- 
 dents are of little use unless the extent of the injury is indicated in 
 some manner. The Mining Acts prescribe that all serious non- 
 fatal accidents, and all accidents causing personal injury arising 
 from any explosion of gas, powder, or of any steam boiler shall 
 be reported to the inspector. In France, on the other hand, the 
 official statistics f do not include non-fatal accidents which have 
 disabled the person for less than three weeks. 
 
 Mining is sometimes a source of risk to the public as well as to 
 the actual workers. The commonest danger arises from unfenced 
 or insecurely fenced shafts, or, what are worse, shafts which 
 have been covered with timber and earth 
 and become forgotten. Every now and 
 then the local papers of mining districts 
 record the sudden and unexpected giving 
 way of a rotten "sollar," leaving a 
 yawning crater in what was thought to 
 be solid ground. Fatal accidents to men 
 and beasts have taken place in this 
 manner, to say nothing of many very 
 narrow escapes. 
 
 Ambulance Training. Though pre- 
 vention is better than cure, and though 
 the number of casualties may be reduced, 
 it cannot be expected that mining will 
 ever be quite exempt from them. Pro- 
 vision should therefore be made io ren- 
 der those that do occur as little harmful 
 as possible. The Coal Mines Act of 
 1887 compels the owners of mines to 
 keep a supply of splints and bandages 
 ready, and many miners have learnt in 
 the school of actual practice how best 
 to assist their injured comrades before 
 the arrival of a doctor. Nowadays the 
 establishment of classes under the St. 
 
 John Ambulance Association;]: has given the men the opportunity 
 of acquiring systematic instruction in the best methods of ren- 
 
 * Report to Her Majesty's Principal Secretary of State for the Home 
 Department by the Quarry Committee of Inquiry, London, 1894, Parlia- 
 mentary Paper [C. 7237.] 
 
 t Statisttique de V Industrie Minirale et des Appareils a vapeur en France ct 
 en Alytrie, pour VAnnee 1886, Paris, 1888, p. 95. 
 
 St. John's Gate, Clerkenwell, London, E.G. 
 
ACCIDENTS. 713 
 
 dering first aid to the injured, and of moving them without 
 aggrav&t'ng the mischief or causing needless pain. Miners 
 all over the world have reason to be grateful to this excellent 
 Society. Fig. 709 illustrates the " Furley " pattern stretcher, as 
 
 FIG. 710. 
 
 supplied by the St. John Ambulance Association, together with 
 the " Lowmoor Jacket," by means of which an injured person 
 can safely be placed at any angle. Figs. 710 and 711 represent the 
 " Ashford Litter," a two-wheeled carriage for the conveyance of 
 the injured person along roads. The former shows that the 
 
 FIG. 711. 
 
 bearers of the stretcher can pass between the wheels, by stepping 
 over a crank axle, and so avoid lifting the heavy weight over the 
 wheels. At large mines there should be a horse ambulance 
 carriage for the removal of sufferers. 
 
 Regular ambulance corps have been established at some mines ; 
 probably the largest in the United Kingdom belongs to Colonel 
 Seely's collieries, already notable for the aid given to sports and 
 pastimes. The corps now musters some 400 men, or about one- 
 
714 ORE AND STONE-MINING. 
 
 tenth of the total number of employes ; the members wear a neat 
 uniform and are regularly drilled. Many others among the 
 workmen, though not belonging to the corps, have received 
 instruction in the ambulance classes. Incalculable good is done 
 by trained men of this kind, who are ready on the spot to render 
 first aid at any moment to an injured comrade and superintend 
 his removal to a hospital; the excellent example thus set might 
 well be followed in all mining districts. 
 
INDEX 
 
 ABEL and Noble, on fired gunpow- 
 der, 209 
 Aberllefenny, method of working 
 
 slate at, 314 
 
 Abyssinian tube wells, 137 
 Acacia, 228 
 Accident club, deduction for, 639, 
 
 690 
 
 Accidents, carriage of injured per- 
 sons, 713 
 
 classification of, 704 
 
 death-rate from, 698 
 
 first aid in case of, 712 
 
 from explosives, 706 
 
 from falls of ground, 704 
 
 from underground fires, 708, 709 
 
 in boring, 130 
 
 in coal mines and in metal 
 mines, 700 
 
 in shafts, 705 
 
 miscellaneous, underground, 
 708 
 
 non- fatal, 712 
 
 on inclined planes, 708 
 
 on the surface, 711 
 
 societies for relief of distress 
 caused by, 691 
 
 statistics of, 698, 703 
 Acme pick, 153 
 Acts, Alkali, 665 
 
 Boiler Explosion, 666 
 
 Brine, Pumping, 666 
 
 Coal Mines Regulation, 662 
 
 Elementary Education, 666 
 
 Employers' Liability, 666 
 
 Explosives, 666 
 
 Factory and Workshop, 667 
 
 Metalliferous Mines Regulation, 
 656 
 
 Quarry Fencing, 667 
 
 Rating, 655 
 
 relating to Derbyshire, 655 
 
 Acts continued. 
 
 relating to Forest of Dean, 655 
 Rivers Pollution Prevention, 
 
 667 
 
 Slate Mines, 659 
 Stannaries, 668 
 Truck, 668 
 
 Adelaide drill, 195 
 
 Adit, Atlantic-Pacific, 437 
 
 Blackett level, Northumber- 
 land, 435 
 
 Cornwall County, 435 
 drainage by, 433 
 Ernst August Stolln, 434 
 Halkyn tunnel, 435 
 Kaiser Josef II., Pfibram, 434 
 Kaiser Josef Erbstolln, 434 
 Mansfeld copper mines, 434 
 Monteponi, Sardinia, 435 
 Rothschonberger Stolln, 434 
 Sutro Tunnel, Nevada, 436 
 working deposit by, 308 
 
 Advantages of steel supports for 
 levels, 257 
 
 Adventitious finds of valuable 
 minerals, 95 
 
 Aerial ropeways, 380 
 incline, 406 
 
 Agglomeration, p-eparation for 
 market by, 565 
 
 Air, causes of pollution of, 480 
 composition of, 475 
 evil effects of dust in, 685 
 friction of, 510 
 measuring velocity of, 506, 
 
 597 
 testiug the quality of, 498 
 
 Air-brake for self-acting incline, 
 Bilbao, 376 
 
 Air-compressors, 164 
 Angstrom's, 165 
 Burckhardt and Weiss, 166 
 dry, 1 66 
 Hanarte's, 165 
 
7 i6 
 
 INDEX. 
 
 A ir-cOmpressors continued. 
 Ingersoll-Sergeant, 167 
 injection, 166 
 water-column, 165 
 Air-current, resistance to, 510-512 
 Air-drying, 592 
 Air-hose, 171 
 Air-lock, 278 
 Air-mains, 170 
 Air-pipe for ventilating shallow 
 
 shafts, 488 
 Air-reservoir, 168 
 
 underground, advantages of, 
 
 169 
 
 Air-sollar, 486 
 
 Air-space required per man, 674, 676 
 Alabaster, occurrence of, in Iialy, 
 
 51 
 
 Algachi silver mines, cold at, 669 
 Algeria, discovery of phosphate of 
 
 lime in, 96 
 
 Alkali Acts as affecting mines, 665 
 Alluvial beds, mode of working, 291 
 diamond deposits, 39 
 gold-mining, California, 318 
 tin ore deposits, 85 
 
 method of working, 316 
 Almaden, mercurial poisoning 
 
 among miners, 687 
 mine, 72 
 Alta, definition of, 1 1 
 
 in quicksilver mines, 73 
 Altenberg, calamine deposit, 19 
 
 Saxony, tin stockwork at, 84 
 Alum-stone, 20 
 Alunite, 20 
 
 Amalgam, retorting of, 598 
 Amalgamation, 616 
 Amber, dressing of, 618 
 liquefaction of, 598 
 mode of occurrence, 21 
 working for, 304 
 Ambulance corps, 713 
 
 training, 712 
 
 American phosphate kiln, 594 
 pitch pine, 227 
 system of boring, 137 
 Ammonite, 215 
 Ammeberg, Sweden, beds of zinc 
 
 blende at, 87 
 Amorpha canescens, 104 
 Amygdaloid, copper-bearing, of 
 
 Lake Superior, 35 
 Anaconda Mine, Montana, 37 
 
 gozzan, 1 02 
 Andreasberg, St., man engine at, 
 
 535 
 
 Anemometers, 507 
 Angers, arc-lamp at, 524 
 
 Ar gers continued. 
 
 slate mining, 314 
 Angle for ladders, 530 
 Angstrom's air-compressor, 165 
 Animals as indicators, 105 
 Anomalies in mineral repositories, 
 
 17 
 
 Anticlinals, 47, 48 
 Antimony ore, liquation of, 598 
 
 mode of occurrence, 21 
 Antiseptics applied to timber, 230 
 Anzin collieries, France, shower- 
 baths, 68 1 
 
 steel frames, 259 
 Arc-lamp at Angers, 524 
 
 Maros-Ujvar, 524 
 
 Mechernich, 524 
 
 Osceola Co.'s Mine, 525 
 
 Rio Tinto, 525 
 Ardennes; method of mining slate, 
 
 3H 
 
 Arizona, copper in, 37 
 Armstrong's electric signalling, 533 
 Arrastra, 556, 618 
 Arrault, free-falling tools, 129 
 
 on boring rods, 125 
 Arsenic, preparation of, 619 
 
 flues, clothing worn when 
 
 clearing out, 673 
 
 Arsenical minerals, effects of in- 
 haling dust from, 686 
 ores, calcination of, 611, 613 
 mode of occurrence, 21 
 sores, 686 
 
 Arsenious acid, preparation of, 619 
 Artificial ventilation, 490 
 Aruba Island, origin of phosphate 
 
 of lime at, 69 
 Asbestos, dressing of, 619 
 
 mode of occurrence, 21 
 Ascensional theory of formation of 
 
 mineral veins, 15 
 Ascent, 526 
 
 Ashburner on the occurrence of 
 natural gas in the United States, 
 
 59 
 
 Aspen case, 9 
 
 Asphaline, 211 
 
 Asphalt, dressing of, 619 
 mode of occurrence, 22 
 rock, preparation for :-ale, 598 
 
 Association of minerals, 97 
 
 Atkinson, Messrs. L. & (J. , on elec- 
 tric transmission of power, 172 
 
 Atlantic Copper Mine, Lake Su- 
 perior, 37 
 
 Atlantic- Pacific Tunnel, 437 
 
 Atlas powder, 214 
 
 Atmospheric weathering, 610 
 
INDEX. 
 
 Attaching hauling rope to hanger, 
 
 Otto system, 382 
 Attachment of rope to bucket, cage, 
 
 &c., 402 
 of waggons to endless rope, 
 
 368, 379 
 Auger, 113 
 
 for boring holes for blasting, 
 
 154 
 
 stem, 139 
 Australia, candle-holder used in, 
 
 515 
 trees used for mining purposes, 
 
 228 
 
 Australian puddling machine, 539 
 Austria, graphite in, 50 
 
 slides for descent used in, 527 
 Automatic dumping cage, 419 
 skip, 412 
 
 stopping gear to prevent over- 
 winding, 424 
 water tank, Bo wd en's, 440 
 
 Galloway's, 438 
 Axles, attachment of, 357 
 lubrication of, 358 
 
 BACK of lode, 106 
 
 Backstay, 366, 396 
 
 Bagnall's sleeper, 352 
 
 Bainbridge, Emerson, on miners' 
 
 cottages, 677 
 on steel beams, 256 
 Baird's machine, 204 
 Baku, occurrence of petroleum at, 
 
 65 
 
 Ballarat " indicators," 13, 16 
 
 Ball-grinders, 557 
 
 Ball-Norton magnetic separator, 
 
 603, 606 
 Ball stamp, 551 
 Band-wheel, 138 
 Banket, or auriferous conglomerate, 
 
 4i 
 
 Barber, mine, 639 
 
 Barracks for workmen, Kimberley 
 Diamond Mines, 676 
 
 Man sf eld, 674 
 
 Mechernich, 674 
 
 North Wales, 676 
 Barrow drill, 183 
 Barytes, 23 
 
 bleaching of, 609 
 
 dressing of, 619 
 
 vein in Shropshire, 13 
 Batea, 539 
 Bath, workings for freestone, 310 
 
 Bath-stone, 41 
 
 Bavaria, graphite in, 50 
 
 Baxter's stone breaker, 547 
 
 Bearer, 237 
 
 Beaumont's tunnelling machine, 
 
 206 
 
 Becker on inflammable gas in quick- 
 silver mines, 478 
 on the Comstock lode, 76 
 on the interstitial space in 
 
 sandstone, 18 
 on the quicksilver deposits of 
 
 California, 71, 73 
 on the quicksilver deposits of 
 
 the Pacific slope, 16 
 Bed of pyrites at Kammelsberg 
 
 Mine, Hartz, 32 
 Bed-planks, 405 
 Bed-rock, 318 
 Beds, 5 
 
 crumpling of, 88 
 
 faults and irregularities in, 88 
 
 occurrence of zinc-blende in, 87 
 
 recovery of faulted portion, 9 
 
 temporary pillars, 315 
 
 worked with permanent pillars, 
 
 309 
 Bedson on the fumes produced by 
 
 roburite and tonite, 481 
 Bell box, 131 
 Bellite, 215 
 
 Bellom on loss in dressing, 630 
 Bell pits, Roumam'a, 311 
 Belt, Brunton's endless, 585 
 
 Stein's endless, 586 
 Belts, picking, 542 
 Benching, 311 
 Bendigo gold-field, 47 
 Benzine, in preparation of ozokerite, 
 
 609 
 
 Bertrand Mill, work by rolls at, 556 
 Bex, Switzerland, blower of marsh 
 
 gas, 478 
 
 use of bosseyeuse, 224 
 workings for salt, 307 
 Bilbao, iron ores of, 102 
 Biram's anemometer, 507 
 Bischoff, Mount, dressing tin ore at, 
 
 630 
 
 Bishop's head, 457 
 Bismuth ore, magnetic separator 
 
 used in dressing of. 606 
 Bit for boring by hand, 157, 158 
 Bits for machine drills, 181 
 Bituminous limestone, preparation 
 
 of, 598 
 
 Val de Travers, 22 
 
 /sandstone in California, 22 
 
 treatment of, 619 
 
7 i8 
 
 INDEX. 
 
 Biwabik iron mines, discovery of, 
 
 94 
 
 Blackett level, Northumberland, 435 
 Blackley, Kev. Canon, on old age 
 
 pensions, 694 
 Blake's stone-breaker, 546 
 Blanchet, pneumatic hoisting appa- 
 ratus, 427 
 
 Blanzy, boring ram at, 187 
 Blast, large, 290, 291 
 Blasting, accidents from, 706 
 
 explosives used for, 209 
 
 gases produced by, 481 
 
 gelatine, 214 
 
 Knox system, 162 
 
 laying dust produced by, 685 
 
 oil, 212 
 
 safety fuse for, 217 
 
 tools for charging holes for, 160 
 
 under water, fuses for, 217 
 
 with gunpowder, 217 
 
 with nitro-compounds, 218 
 Bleaching barytes, 609 
 Blende, dressing of, 625, 630 
 
 occurrence of, 85 
 
 separation of, from iron pyrites, 
 
 607 
 
 Blondin for raising stone from quar- 
 ries, 405 
 Blount on liquid carbonic acid in 
 
 minerals, 476 
 Blue-ground, 38 
 
 method of working, De Beers 
 
 mine, 341 
 
 Bluestone of Anglesey, 33 
 Boats, conveyance by, 372 
 Bochkoltz regenerator, 459 
 Bohemia, dressing of graphite in, 
 
 623 
 Boiler Explosion Acts, 666 
 
 explosions, 711 
 Bolsover collieries, miner's cottage, 
 
 677 
 
 Bonanza, definition of, n 
 Booming, 293 
 Boots, 672 
 
 worn by rockmen, Festiniog, 
 
 673 
 Borax, 23 
 
 lake, California, 23 
 preparation of, 608 
 treatment of, in California, 620 
 Bord, 315 
 
 Bore-holes, conveying water to bot- 
 tom of, 187 
 deviation of, 148 
 extraction of minerals by, 304 
 for extracting salt, Middles- 
 brough, 305 
 
 Bore-holes continued. 
 lining for, 131, 140 
 remedying deviation of, 130 
 removal of debris from, 118, 12S> 
 
 141 
 
 surveying, 147 
 triangular, 159 
 uses of, 113 
 Borers, 157 
 Boric acid, mode of occurrence, 25 
 
 preparation of, 620 
 Boring, accidents to rods, &c., 130 
 ascertaining dip and strike of 
 
 strata, 132 
 
 at Port Clarence, 137, 142 
 by American system, cost of 
 
 142 
 by percussion with rods, 124 
 
 with rope, 137 
 by rotation, 113 
 crown, Docwra's diamond setting 
 
 for, 118 
 
 double-handed, 158 
 free-falling tools, Arrault, 129 
 
 Kind, 130 
 hand-power diamond drills for, 
 
 123 
 
 hand tools for, 154 
 head, Mather's, 145 
 holes for blasting, prevention of 
 
 dust, 685 
 
 holes of elongated section, 162 
 Mather and Platt's system, 142 
 method of sinking shafts, 271 
 Oeynhausen's sliding joint, 128 
 pits for wire saw, 205 
 portable set of tools for hand- 
 power. 117 
 process of, 128 
 ram or bosseyeuse, 186 
 rods, iron, 125 
 single-handed, 158 
 tools, 127 
 
 with diamond drill, cost of, 122 
 with the diamond drill, 118 
 with wooden rods, 134 
 cost of, 136 
 speed of, 136 
 Boryslaw, dressing of ozokerite at, 
 
 626 
 mode of occurrence of ozokerite 
 
 at, 64 
 safety gear for hauling men, 
 
 53.1 
 sinking shafts with windlass, 
 
 388 
 steel rings for supporting shaft 
 
 linings, 265 
 Po-'seyeuse, 186 
 
INDEX. 
 
 liossey cuse continued. 
 
 used for cutting groove, 224 
 Bower's coal- cutting machine, 206 
 Bowie, Hydraulic Mining, 293 
 Bowk, 408 
 
 Brain's high tension fuse, 220 
 Brandt's drill, 178 
 Brattice, 487 
 Breaker, Baxter's stone, 547 
 
 Blake's stone, 546 
 
 Gates' stone, 560 
 
 Hall's stone, 547 
 
 Lester's stone, 547 
 
 Marsden's stone, 547 
 Breaking ground, 151 
 
 machines, uses of, 564 
 
 up minerals, 542 
 
 use of holes for, 207 
 Breast boards, 236 
 Brick linings for levels, 251 
 
 for shafts, 252, 267 
 Bridge-rails converted into sleepers, 
 
 Brirlgman's ore-sampler, 635 
 Brine, evaporation of, 609 
 
 Pumping Act, 666 
 
 wells, 306 
 
 Briscale (Sicily), 102 
 Broach, 201 
 Broken Hill mines, 78 
 
 cost of boring by the diamond 
 drill at, 122 
 
 discovery of, 96 
 
 lead poisoning among miners, 
 687 
 
 outcrop of lode, 98 
 
 square set timbering, 249 
 Brough, on concrete liuings for 
 shafts, 254 
 
 on searching for iron ore with 
 
 the magnetic needle, 112 
 Brown coal bed at Briihl, 5 
 Bruccioni, 100 
 Bruckner furnace, 613 
 Briihl, bed of brown coal at, 5 
 Brunton's endless belt, 585 
 
 furnace, 596, 613 
 
 sampling machine, 635 
 
 tunneller, 206 
 Buchanan, magnetic separator, 
 
 604 
 
 Bucket of lifting pump, 448 
 Buckets, for descent and ascent, 
 
 53i 
 
 for hoisting, 404 
 Bucking, 545 
 Buddies, 587 
 
 Bulkhead (hydraulic mining) 295 
 Bull, 158 
 
 Bullakdelah Mountain, N.S.W., 
 al unite at, 20 
 
 Bull engine, 443 
 
 Bullion mine, heat at, 670 
 
 Bullock Manufacturing Co., dia- 
 mond drills, 119 
 
 Bull- wheel, 139 
 
 Bunch of ore, definition of, 1 1 
 
 Bunning, 330 
 
 Buntons, 237 
 
 Burckhardt and Weiss air-com- 
 pressor, 1 66 
 
 Burmah, oil-fields of, 65, 66 
 
 working without light in, 513 
 
 Butterfly valve, 453 
 
 CAE COCH Mine, Carnarvonshire, 309 
 mode of working, 309 
 occurrence of pyrites, 83 
 pumping with compressed air, 
 
 47i 
 
 Cage, advantages of winding men 
 in, 688 
 
 Carn Brea mine, 533 
 
 Comstock lode, 418 
 
 for descent and ascent, 532 
 
 Junge hohe Birke mine, 533 
 
 s- elf -dumping, 419 
 Calamine deposit, Altenberg, 19, 87 
 
 pansy, 104 
 
 roasting at Monteponi, 615 
 Calcarone, for sulphur rock, 599 
 Calcination of arsenic ores, 611, 613 
 
 clay ironstone, 611, 612 
 
 copper ores, 612, 613 
 
 gypsum, 611, 613 
 
 limestone, 6n, 613 
 
 ores, objects of, 611 
 
 tin ore?, 612, 613 
 
 zinc ores, 612, 615 
 Caliche, 62 
 
 mode of working, 286 
 
 preparation of, 608 
 California, bituminous sandstone 
 of, 22 
 
 borax deposits of, 23 
 
 drift mining, 318 
 
 gold in, 45 
 
 hydraulic mining in, 302 
 
 quicksilver deposits of, 73 
 
 treatment of borax, 620 
 
 and Consolidated mines, heat 
 
 at, 670 
 Gallon on working salt marls of 
 
 the Salzkammergut, 307 
 Calumet and Hecla Mine, 36 
 
720 
 
 INDEX. 
 
 Calumet and Hecla mine continued. 
 
 fire at, 709 
 
 shaft timbering, 240 
 
 stamps at, 553 
 Canada, asbestos in, 2 1 
 
 nickel ore in, 61 
 Canadian system of boring, 134 
 Cancer of lungs among miners, 685 
 Candle holders, 514, 515 
 
 used for testing quality of air, 
 
 5 01 
 Candles, sperm and composite, 514 
 
 tallow, 513 
 
 Canton Mine, lode at, 8 
 Cap, in timbering, 232 
 
 on flame of alcohol lamp, 500 
 benzine lamp, 499 
 hydrogen lamp, 500 
 safety lamp, 499 
 Capell fan, 495 
 Capping ropes, 402 
 Capstan for hoisting, 388 
 
 for pumping machinery, 461 
 Caratal gold-field, 44 
 
 gold diggings, birds at, 105 
 CarVolineum, 231 
 Carbonas, 84 
 
 Carbonic acid gas conveyed by 
 pipes, 374 
 
 mode of occurrence, 25 
 
 in air, an index of its impurity, 
 480 
 
 in the air of mines, 475, 501 
 
 liquefaction of, 600 
 
 preparation of, 620 
 
 testing for, 501 
 Cariboo, timbering levels, 233 
 Carnallite, occurrence of, 70 
 Carn Brea Mine, winding men, 533 
 Carne, J., definition of a mineral 
 
 vein, 6 
 
 Carrett and Marshall's machine, 199 
 Carriage of injured persons, 713 
 
 minerals by persons, 349, 375 
 Carriere, definition of, I 
 Carr's disintegrators, 559 
 Cars, 355 
 Cartridges, hydraulic, 208 
 
 lime, 208 
 
 Cartridge-stick, 161 
 Casing boards, 238 
 Cassiterite, minerals associated 
 
 with, 97 
 
 C/ast-iron columns used at Halkyn 
 tunnel, 255 
 
 lining for soft strata, 268 
 
 lining for tunnels, 263 
 
 props, 265 
 
 tubbing, 269 
 
 Catches, 460 
 
 Cementation, 616 
 
 Cement works affected by Alkali 
 
 Acts, 665 
 Centrifugal concentrator, 591 
 
 grinders,56i 
 Ceylon, dressing of graphite in, 623 
 
 graphite in, 50 
 Chains, 401 
 Chamberlain, Mr. Joseph, on State 
 
 pensions, 694 
 
 Chance discoveries of mineral de- 
 posits, 93 
 
 Changing house, 679 
 Channelling machines, 201 
 Chapeau en fer, or gozzan, 100 
 Chapin iron mine, Michigan, 54 
 Charging- spoon, 161 
 Chase, magnetic separator, 601 
 Chateaugay Co., dressing magnetite, 
 
 624 
 Cheeks or walls of a lode, definition 
 
 of, 10 
 
 Chert, dressing of, 622 
 Cheshire mines, preparation of salt, 
 628 
 
 jumper used at, 157 
 
 salt mines, 311 
 
 salt wells, 306 
 Chesneau on testing for firedamp, 
 
 500 
 
 Chilian mill, 557 
 
 Chilled cast-iron shot, use of, for 
 boring, 124 
 
 wheels, 357 
 
 Chimney built over shaft for ven- 
 tilating, 484 
 China-clay, 27 
 
 discovery of, 99 
 
 dressing of, 620 
 
 drying of, 592 
 
 workings in Cornwall, 292 
 Chlorate mixtures, 21 1 
 Chocks or cribs, 245 
 Chollar-Potosi mine, heat at, 670 
 Chromic iron in New Caledonia, 28 
 Churns, Forest of Dean, 340 
 Churprinz mine, Freiberg, spherical 
 dam at, 432 
 
 works, loss at, 631 
 Chute of ore, 1 1 
 Cinnabar, occurrence of , 71 
 Circular saw groove-cutters, 202 
 
 used for slate, 564 
 Clack, 448, 453 
 
 -piece, 448 
 
 seat piece, 448 
 Clanny lamp. 519 
 Clarkson's rapid sampler, 634 
 
INDEX. 
 
 721 
 
 Clarkson - Stanfield concentrator, 
 
 59i 
 Classification of dressing processes, 
 
 538 
 
 mineral deposits, 5 
 rocks, 3, 4 
 Clay, 26 
 
 Glaring bar, 161 
 Clay ironstone, calcination of, 611, 
 
 612 
 
 weathering of, 6n 
 Clays, dressing of, 620 
 Clay-slant, 222 
 
 Cleaning-up. hydraulic mining, 299 
 Cleasage of slate, 81 
 Cleveland, discovery of salt bed at, 
 
 96 
 
 district, royalties in, 654 
 iron-mines, jumper used at, 157 
 ironstone, method of working, 
 
 315 
 mode of occurrence of, 51- 
 
 Sorby on the origin of, 
 
 18 
 
 Clevis, 402 
 Clifton, tests of light given by 
 
 Clanny lamp, 520 
 Davy lamp, 519 
 Climax drill, 185 
 Clinograph, Macgeorge's, 147 
 Clinostat or dip-recorder, 147 
 Clogs, 672, 673 
 Clothing for men engaged near 
 
 machinery, 673 
 of miner, 669 
 worn when cleaning arsenic 
 
 flues, 673 
 
 Clowes hydrogen lamp, 500 
 Club, deductions for accident, 639 
 Coal, discovery of, in south-east of 
 
 England, 97 
 
 Coal Mines Regulation Act, 662 
 accident statistics under, 700 
 tools for charging holes, 161 
 Cobalt mines, Saxony, cancer of 
 
 lungs among miners, 686 
 ore in Flintshire, discovery of, 
 
 93 
 
 New Caledonia, 28 
 Rhyl, Flintshire, 28 
 Skutterud, Norway, 27 
 Cobbing, 544 
 Coffering, 267 
 Cold at mines, 669 
 Colle Croce mines, Lercara, Sicily, 
 
 thick sulphur seam, 321 
 Collieries affected by Alkali Acts, 
 665 
 
 Collins on the china clay of Corn- 
 wall, 27 
 on the Great Mother Lode of 
 
 California, 46 
 
 on the ores of Rio Tinto, 33 
 on the pyrites deposits of 
 
 Huelva, 32 
 Collom jigs, 621 
 Colorado, lead ores of, 57 
 lease system, 647 
 sampling machine 5 ! used in, 634 
 tribute system in, 647 
 Colorados, 100 
 Colour as an aid to the prospector, 
 
 99 
 Comparative mortality figures, 683, 
 
 684 
 
 Compound for native miners, Kim- 
 berley, 677 
 
 engines for pumping, 443 
 Comprtssed air cartridge, 208 
 
 locomotives, 363 
 
 loss of power from use of, 164 
 
 pipes, 170 
 
 Dumping with, 470, 471 
 
 reservoir 169 
 
 sinking by aid of, 277 
 
 stamps, 551 
 
 use for ventilating workings, 
 
 493 
 
 Compressors, air, 164 
 Comstock lode, description of, 76 
 
 discovery of, 95 
 
 gases met with, 476 
 
 gozzan, 100 
 
 heat on the, 670 
 
 influence of heat on health, 
 689 
 
 lifting pump used on, 449 
 
 shaft timbering, 238 
 
 square-set system of timbering, 
 246 
 
 timbering for levels, 233 
 Concentrator, centrifugal, 591 
 
 Clarkson and Stanfield, 591 
 
 Embrey, 586 
 
 Woodbury, 586 
 Concrete blocks, 253 
 
 used for lining levels, 251 
 
 shafts, 253 
 
 Condition of miner, 669 
 Congenial beds, 13 
 Conglomerate, copper-bearing, 35 
 Conical grinders, 560 
 Conkling magnetic separator, 601 
 Convolvulus althseoides, 104 
 Cook's Kitchen mine, heat at, 670 
 Co-operative pumping, 474 
 
 societies, 696 
 
 2 Z 
 
722 
 
 INDEX. 
 
 Coppei at Lake Superior, 34 
 
 extraction of, in solution, 307 
 
 precipitation of, 616 
 mines affected by Alkali Acts, 
 
 665 
 ore, discovery of on Yorke's 
 
 peninsula, 93 
 calcination of, 612, 613 
 dressing of, 621 
 in Germany, 29 
 in Spain and Portugal, 31, 
 
 34 
 
 in the United States, 34, 37 
 occurrence of, 28 
 separation from tin ore, 609 
 Cores, ascertaining dip from, 132 
 cutting out, 1 33 
 extractor, 119 
 
 Arranlt's, 132 
 Bullock's improved, 121 
 modes of obtaining, 132 
 obtained by boring with flat 
 
 rope, 147 
 
 produced in boring pits, 205 
 tube for diamond drill, 119 
 Corf, derivation of term, 405 
 Cornish " dry " for china ciay, 592 
 miner's boot, 672 
 
 hat, 671 
 
 pumping engine, 443 
 rolls, 553 
 Cornwall, annual death-rate of 
 
 miners, 684 
 county adit, 308 
 dressing of tin ore in, 629 
 gozzans, 102 
 mode of occurrence of tin in, 
 
 7, 19, 84 
 royalties in, 654 
 tin lodes of, 7 
 Corrosive water, pumps for, 450 
 
 valves for, 453 
 Cost of aerial ropeway, 385 
 
 antiseptic treatment of timber, 
 
 231 
 
 barracks for workmen, 676 
 coffering shaft, 268 
 co-operative pumping, 474 
 cottages, 677 
 driving level at Bex, 224 
 electric haulage, 372 
 lodgings, &c., for workmen, 
 
 Eisleben, 676 
 sinking through watery strata, 
 
 271 
 steel supports for levels, 256, 
 
 257 
 
 transport by aerial ropeway, 
 386 
 
 Cost of continued. 
 
 working Dolcoath man-engine, 
 
 535 
 working gold-bearing gravel, 
 
 California, 320 
 
 Counterbalancing weight of pump- 
 rods, 457 
 
 rope in winding, 393 
 Counterpoise for rods, variable, 
 
 460 
 Country, definition of term, 10 
 
 influence of, on lode, 12 
 County adit, Cornwall, 435 
 Course of ore, definition of, 1 1 
 Cox, S. H., on an alunite deposit in 
 
 N.S.W., 20 
 
 on the colour of vegetation, 104 
 Creep, 309 
 Crib, or curb, 252 
 Cross-course, or fault, 91 
 Crow's-foot, 130 
 Crump and Brereton's machine, 
 
 202 
 Crusher, 546 
 
 Cornish, 553 
 Dodge, 547 
 Gates, 560 
 Crushing in of workings, Sicilian 
 
 sulphur mines, 321 
 Crystalline schists, 3 
 Crystallisation, borax, 6oS 
 nitrate of soda, 608 
 potassium salts, 608 
 magnesium chloride, 609 
 Cundill, on explosives, 209 
 Curb, cast-iron, 267, 270 
 Cuvelier's lock for safety lamps, 
 
 522 
 Cyclone pulveriser, 563 
 
 D 
 
 DAM, temporary, 433 
 
 Dams, masonry, 433 
 
 spherical wooden, 431 
 wooden, 430 
 
 Darkness, working in, 513 
 
 Darley, on boring by rotation, 117 
 
 Darlington drill, 195 
 
 Daubree on the artificial formation 
 of minerals, 1 7 
 
 Dauntless diamond drill, 119 
 
 Davey's differential pumping en- 
 gine, 445, 466 
 
 Davis' self-timing anemometer, 507 
 
 Davy lamp, 619 
 
 Day Dawn mine, pigsty timbering, 
 245 
 
INDEX. 
 
 723 
 
 Day Dawn mine continued. 
 shaft timbering, 239 
 timbering, 234 
 Day-level, 433 
 Daylight, working by reflected, in 
 
 California and Japan, 513 
 Death-rate of miners from acci- 
 dents, 698 
 Death-rates, annual, for various 
 
 trades, 684 
 De Beers diamond mine, 38 
 
 endless rope haulage at surface, 
 
 376 
 
 head-gears, 397 
 method of working, 341 
 self - discharging skips, 412, 
 
 415 
 
 washing machine, 540 
 Deep leads of Australia, 85 
 Deflection magnetic separator, 606 
 Deposition from solution, formation 
 
 of veins by, 14 
 Derbyshire, Mining Acts relating to, 
 
 655 
 Derrick for boring by percussion 
 
 with rods, 125, 136 
 by rotation, 117 
 with rope, 137 
 
 Descent and ascent of miners, 526 
 Desiccation in dressing, 592 
 Detaching hooks, 422 
 Detonators, 216 
 
 strength of, 219 
 
 Devonshire, dressing of clay, 620 
 manganese ore, 625 
 umber, 626 
 
 Diamond, substitutes for, for drill- 
 ing, 124 
 Diamond-bearing rock, De Beers, 
 
 dressing of, 621 
 method of working, 341 
 weathering of, 610 
 Diamond, discovery of, in South 
 
 Africa, 93 
 occurrence of, 37 
 washing machine for, 539 
 Diamond drill, American Diamond 
 Rock Boring Company's, 121 
 boring at Johannesburg, 119 
 
 Northampton, 118 
 boring with the, 118 
 Bullock Manufacturing Com- 
 pany's, 119, 123 
 core extractor, 119 
 
 Bullock's improved, 121 
 cost of boring by, 122 
 crown, 118 
 "Dauntless," 119 
 differential feed gear, 119 
 
 Diamond drill continued. 
 
 for boring holes for blasting, 
 179, 1 80 
 
 Georgi's electric, 124 
 
 Little Champion, 123 
 
 prospecting, 123 
 
 sediment tube for, 119 
 
 Sullivan's prospecting, 124 
 
 Swedish for hand-power, 123 
 
 thrust register, 121 
 
 Victorian "Giant Drill," 121 
 Dickinson's anemometer, 507 
 
 water-gauge, 509 
 Diepenlinchen, pumping engine at, 
 
 445 
 
 working zinc ore at, 345 
 zinc ore stockwork, 87 
 Diffusion of gases, 485 
 Dig, definition of, 1 1 
 Ding Dong mine, fire-damp in level 
 
 at, 477 
 Dip, definition, 5 
 
 influence of change of on veins, 
 
 13 
 
 Dipping needle, 1 1 1 
 Discovery of minerals, 93 
 Diseases caused by arsenical mine- 
 rals, 687 
 
 inhalation of dust, 685 
 
 ladder climbing, 688 
 
 lead ores, 687 
 
 quicksilver ores, 687 
 Disintegrators, 559 
 Distillation, of rich sulphur rock, 600 
 
 use in dressing, 600 
 Dividings, 237 
 Divining rod, 1 1 1 
 Doctor, deduction for, 639 
 Docwra, diamond setting for boring 
 
 crown, 118 
 Dodge Crusher, 547 
 Dolcoath Mine, Cornwall, 328, 329. 
 
 man- engine, cost of working, 
 
 535 
 
 heat at, 670 
 Dolly, or swage, 181 
 Dolly tub, or keeve, 570 
 Dorothea mine, Clausthal, under- 
 ground traffic by boats, 373 
 Double-beat valve, 454 
 Douglas spruce, 228 
 Downcast shaft, 484 
 Downthrow, 91 
 Dowsing rod, 1 1 1 
 Drainage, 429 
 
 by adit, 433 
 
 by pumps, 441 
 
 by siphon, 437 
 
 by winding machinery. 437 
 
724 
 
 INDEX. 
 
 Drawing lift, 448 
 Dredges, 175 
 
 grab, 176 
 
 Kincaid & McQueen's, 175 
 
 Priestman's grab, 176 
 
 suction, 177 
 Dressing, definition of, 537 
 
 amoer, 618 
 
 arsenic ore, 619 
 
 asbestos, 619 
 
 asphalt, 619 
 
 barytes, 619 
 
 bituminous rock, 598, 619 
 
 blende, 625, 630 
 
 borax, 620 
 
 boric acid, 620 
 
 carbonic acid, 620 
 
 chert, 622 
 
 china clay, 620 
 
 clays, 620 
 
 copper ore, 621 
 
 diamond -bearing rock, 621 
 
 flint, 622, 629 
 
 fuller's earth, 620 
 
 galena, 624, 625 
 
 gold ore, 622 
 
 graphite, 623 
 
 gypsum, 624 
 
 haematite, 624 
 
 iron ore, 624 
 
 lead ore, 624 
 
 loss in, 630 
 
 magnetite (see magnetic sepa- 
 rators), 624 
 
 manganese ore, 625 
 
 mica, 625 
 
 mispickel, 611, 612, 613, 619 
 
 ochre, 626 
 
 ozokerite, 626 
 
 phosphate of lime, 626, 627 
 
 potassium salts, 627 
 
 quicksilver ore, 627 
 
 salt, 628 
 
 silver ore, 628 
 
 slate, 628 
 
 stone, 628 
 
 sulphur rock, 629 
 
 Trinidad pitch, 619 
 
 tin ore, 629 
 
 umber, 626 
 
 zinc ore, 625, 630 
 Drill, ratchet, 155 
 Drilling rig, 138 
 
 tools, 139 
 Drills, Adelaide, 195 
 
 automatic rotation of, 194 
 
 Barrow, 183 
 
 Brandt's, 178 
 
 classification of, 183 
 
 Drills continued. 
 
 Climax, 185 
 
 Darlington, 195 
 
 diamond, 179 
 
 Eclipse, 187, 1 88 
 
 electric percussion, 198 
 
 Elliott, 154, 155 
 
 for boring by hand, 157 
 
 Franke, 189 
 
 Hirnant, 192 
 
 Inger&oll-Sergeant, 193 
 
 Jarolimek, 179 
 
 Marvin, 198 
 
 Optimus, 189 
 
 percussive, 181 
 
 rotary, 177 
 
 Sergeant, 193 
 
 sharpening, 158, 182 
 
 Steavenson, 180 
 
 steel for, 182 
 Drive-pipe, 140 
 Driving levels, 221 
 
 tunnels in soft ground, 263 
 Drums for winding, 391 
 
 wii h reserve of rope, 392 
 Dry compressors, 166 
 
 for China clay, 592 
 
 or changing house, 679 
 
 rot, prevention of, 230 
 Drying of minerals, 592 
 Dubois and Francois air-compressor, 
 1 66 
 
 boring-ram, 186 
 Duck machine, 493 
 Ducktown mine, Tennessee, 108 
 
 blower of sulphuretted hydro- 
 gen, 479 
 
 Dudley, workings for limestone, 311 
 Dumb fault, 87 
 Dunbar and Huston's steam navvy, 
 
 173 
 Dust in mines, evil effects on health, 
 
 685 
 
 in air of mines, 482 
 Duty of the miner's inch, 301 
 of pumping-engines, 472 
 Dykes, definition of, 14 
 Dynamite, 213 
 
 danger from exudation, 213 
 pan for thawing when frozen, 
 213 
 
 EADIE & SONS', joint for lap-welded 
 
 pipes, 171 
 Eclipse drill, iSS 
 
INDEX, 
 
 725 
 
 Edge-runners, 556 
 Edison's deflection magnetic sepa- 
 rator, 606 
 
 second magnetic separator, 602 
 Education Acts, Elementary, 666 
 
 general and technical, 682 
 Efficiency of ventilating appliances, 
 
 509 
 Ekleben, barracks for workmen, 
 
 674 
 Electric drill, Marvin, 198 
 
 Steavenson, 180 
 
 lamp, Sussmann, 523 
 
 light, 524 
 
 percussion drill, 198 
 
 railways, 371 
 Electricity, firing by, 220 
 
 pumps worked by, 470 
 
 transmission of power by, 1 72 
 Elementary Education Acts, 666 
 Elephant stamps, 551 
 Elliot's locked coil wire rope, 400 
 Elliott drill, 155 
 
 multiple wedge, 208 
 Elwen on the resistance to air- 
 currents, 511 
 
 Embrey concentrator, 586 
 Ernmons, S. T., on the geology of 
 the Leadville district, 57 
 
 on the veins in the Kooky 
 
 Mountain region, 7 
 Employers' Liability Act, 666 
 Ems, loss in dressing at, 631 
 End, ventilation of an, 485, 487, 492, 
 
 493 
 
 going into, after blasting, 686 
 Endless chain system of haulage, 
 
 371 
 
 rope system of haulage, 367 
 advantages of, 369 
 attachment of waggons to 
 
 368, 379 
 
 De Beers mine, 378 
 End-piece, 237 
 Equilibrium pipe, 274 
 Erigonum ovalifolium, 104 
 Ernst August Stolln, 434 
 Eucalyptus, species used for mining 
 
 purposes, 229 
 Eureka, Nevada, silver-lead deposits 
 
 of, 77 
 
 square-set timbering, 247 
 Europe, trees used for mining pur- 
 poses, 227 
 Eustice, changing house at Levant 
 
 Mine, Cornwall, 679 
 Evans and Veitch, pump for raising 
 
 water by compressed air, 471 
 Evaporation of brine, 609 
 
 Excavating by water, 226 
 
 machinery, 173 
 
 Excavation of minerals underground, 
 308 
 
 under water, 302 
 Excavations, supporting, 227 
 Exploitation, 285 
 Explosions of fire-damp, 476, 477 
 Explosives, accidents from, 707 
 
 strength of, 216 
 
 used in mining, 209 
 Explosives Act, 666 
 Extraction of minerals by wells and 
 boreholes, 304 
 
 FACTORY and Workshop Acts, 667 
 Fahlbands at Kongsberg, Norway, 
 
 12 
 
 Falls of ground, accidents from, 704 
 Falun, torches ued at, 515 
 Fans, Capell, 495 
 efficiency of, 509 
 Guibal, 496 
 Schiele, 497 
 use of, in dressing, 590 
 Waddle, 497 
 Faults, 87 
 
 length of, 90 
 
 measurement of throw of, 89 
 recovery of lost part of bed, 89 
 recovery of lost part of lode or 
 
 vein, 91 
 reversed, 90 
 variations of throw along the 
 
 strike, 90 
 Feeders or droppers, definition of, 
 
 12 
 
 Fencine Act, Quarry, 667 
 Fend-oft' bob, 446 
 
 Fernow on the trees available for 
 mining purposes in the United 
 States, 228 
 Festiniog, boot worn by rockman, 
 
 673 
 
 method of working slate at, 312 
 preparation of slate at, 628 
 slate mines, charging spoon 
 
 used at, 161 
 drivages at, 222 
 jumper used at, 157 
 tribute system at, 649, 651 
 Field, Mr. Justice, on the Richmond 
 
 v. Eureka case, 8 
 Filling up, working with complete, 
 
 322, 331, 335, 341, 343, 346 
 Fir, Scotch, 228 
 
INDEX. 
 
 Fire-clay, 26 
 
 weathering of, 611 
 Fire-damp found in ore mines, 476 
 
 testing for, 498-501 
 Fireless locomotives, 363 
 Fires, accidents from underground, 
 708, 709 
 
 in sulphur mines, Sicily, 321 
 Fire-setting, 225 
 Firing by electricity, 220 
 
 explosives, 218 
 Firth's pick machine, 199 
 Flare lamp, 516 
 
 Flat-rope, winding with the, 393 
 Flattened strand wire rope, 400 
 Flint, dressing of, 622 
 
 mining at Brandon, Suffolk, 41 
 Flints, shaping of, 629 
 Floating reef in Kimberley dia- 
 mond mines, 38 
 
 Flooded workings, breaking into, 707 
 Flookan, explanation of term, 14 
 Floor of a bed, definition of, 5 
 
 of changing house, 68 1 
 Florida, phosphates of, 69 
 Flume, 204 
 Fluted rolls, 556 
 Foot- wall, definition of, 10 
 Forest of Dean, method of working 
 haematite masses, 340 
 
 Mining Acts relating to, 655 
 Form for pump bucket, 448 
 Form of the ground indicating de- 
 posits, 98 
 
 Formation of mineral veins, 14 
 Formations or classes of lodes, 17 
 Foxdale lead mine, carbonic acid 
 at, 475 
 
 mode of working lode, 335 
 
 strike of lode, 14 
 Frames, 579 
 
 for levels, steel, 260 
 
 wood, 233 
 
 for shafts, 236 
 France, underground workings for 
 
 slate, 314 
 Franke drill, 189 
 Franke's mechanical chisel, 199 
 Free-falling tools, Arrault, 129 
 
 Kind, 130 
 
 Free-milling ores, 101 
 Freestone, 41 
 
 mode of working, 310 
 Freezing method of sinking shafts, 
 
 278 
 
 Freiberg, formations of lodes at, 17 
 French miner's hat, 671 
 Friability, use of in dressing, 607 
 Friction due to sides of airway, 510 
 
 Frongoch jigger, 573 
 
 self-discharging skip, 416 
 
 separator, 576 
 Frozen dynamite, 213 
 Frue vanner, 585 
 
 for gold ores, 622 
 Fuller's earth, 27 
 
 dressing of, 620 
 
 kiln, 595 
 Furnace, Brunton's, 596, 613 
 
 roasting, 6n 
 
 ventilation, 490 
 Furness district, temporary dam 
 
 used in, 433 
 Fuse, electric, 220 
 
 for blasting purposes, 217 
 
 for simultaneous blasting, 220 
 
 G 
 GAD, 154 
 
 Galena, dressing of, 624, 625 
 Galicia, Canadian system of boring 
 
 in, 134 
 
 ozokerite mines of, 63 
 Galloway on the fire-damp cap, 499 
 Galloway's automatic water tanjs, 
 
 438 
 
 double walling stage, 409 
 method of guiding kibble, 408 
 pneumatic water- barrel, 438 
 steel tram, 359 
 winding drum, 392 
 
 Garfield Mine, California, 79 
 
 Garland, 267 
 
 Gamier, discovery of nickel ore in 
 New Caledonia, 99 
 
 Gas for underground lighting, 522 
 
 Gases produced by decomposition 
 
 of gun-cotton, 215 
 of m'tro-compounds, 212 
 explosion of gunpowder, 210 
 blasting, 481 
 
 Gates crusher, 560 
 
 Gatzschmann, on animals as indica- 
 tors, 105 
 
 Gearing pump-buckets, 448 
 
 Geikie, Sir A., definition of a mineral 
 vein, 6 
 
 Gelatine dynamite, 214 
 
 Gelignite, 214 
 
 Geology as a guide to minerals, 97 
 
 German miner's hat, 672 
 
 Germany, amber dredging, 304 
 carbonic acid gas in, 25 
 copper deposits of, 29 
 death-rate from accidents, 699 
 Law of Insurance, 694 
 occurrence of zinc ore in, 87 
 
INDEX. 
 
 727 
 
 Gerolstein, borings for carbonic acid 
 
 gas at, 25 
 Giant granite, 58 
 
 mines, 290 
 
 powder, 214 
 
 Gillott and Copley's machine, 203 
 Gill's furnace for sulphur extraction, 
 
 600 
 
 Githens system of boring, 162 
 Gobert's modification of Poetsch's 
 
 freezing process, 283 
 Gold, amalgamation of, 616 
 
 associated minerals, 97 
 
 in gozzan, 100 
 
 modes of occurrence, 41 
 
 ores, treatment of, 622 
 
 Run Ditch and Mining Co., 302 
 
 worked in Alps by Komans, bib 
 Gold-bearing gravel, method . of 
 mining in California, 318 
 
 prospecting for in Siberia, 278 
 
 working, 293 
 
 yield of, 302 
 
 Good conduct, premiums for, 652 
 Gooseneck, 402 
 Gouge, definition of, 1 1 
 Gozzan, 99 
 
 at the Anaconda mine, 37 
 
 at Rio Tinto, 33 
 
 influence of, on value of ore, 101 
 Graphite, 50 
 
 dressing of, 623 
 
 in Bavaria, 607 
 Gravitation stamps, 548 
 Great Basin, borax deposits of the, 
 
 2 3 
 
 Greathead shield, 263 
 
 Great Laxey Mine, locomotive, 363 
 
 overshot wheel, 442 
 Great Quartz Vein of California, 
 
 length of, 1 1 
 outcrop of, 99 
 Great Western quicksilver mine, 
 
 California, 74 
 outcrop of lode, 98 
 Greaves' circular slate-dressing 
 
 machine, 565 
 Grey box, 229 
 Griffith, on coffering, 268 
 Grime's graves or ancient workings 
 
 for flint, 41 
 Grimm, definition of a mineral vein, 
 
 6 
 
 Grinders, Grusonwerk ball, 557 
 ball, 557 
 centrifugal, 561 
 conical, 560 
 Jordan's, 557 
 See also under CRUSHERS 
 
 Grizzly, 299 
 Groove-cutters, 201 
 Groove-cutting machines, 199 
 Grooves cut by circular saw, 202 
 
 travelling rock drill or jumper, 
 20 1 
 
 made by endless chain with 
 cutters, 204 
 
 revolving bar with cutters, 206 
 
 wire saw, 204 
 
 Grusonwerk ball grinder, 557 
 Gudgeon, 457 
 Guibal fan, 496 
 Guides for shafts, 408 
 Guillotine slate-dressing machine, 
 
 5.65 
 
 Guinotte, pumping-engines with fly- 
 wheel, 444 
 
 Gun for clearing bore-holes, 160 
 
 Gun-cotton, 215 
 
 products of decomposition, 212, 
 
 2I 5 
 
 Gunpowder, 209 
 
 charging holes with, 217 
 
 products of explosion of, 210 
 Gunpowder Act, Slate Mines, 659 
 Gutta-percha packing for puuip, 
 
 448 
 
 Gympie gold-field, lodes of, 13 
 Gypsum, 50 
 
 calcination of, 611, 613 
 
 discovery of, by sub-wealden 
 boring, near Battle, 96 
 
 dressing of, 624 
 
 occurrence of, 50 
 
 quarries, Paris, 309 
 
 HAASE process of sinking shafts, 283 
 Habets on annual death-rate from 
 
 accidents, 699 
 Hade, definition of, 9 
 Haematite at Iron Mountain, Mich- 
 igan, 54 
 
 deposits of the Ulverston dis- 
 trict, 19 
 dressing of, 624 
 method of working, 340, 343 
 searching for by piercing, 106 
 veins of the Lake District, 
 
 Kendall on, 7 
 Haeuser process for sinking in 
 
 quicksand, 284 
 
 Haggie's patent Protector rope, 400 
 Hake's mouth valve, 453 
 Hale and Norcross inine, heat at, 
 670 
 
728 
 
 INDEX. 
 
 Half -moons, 448 
 
 Halkyn Drainage Tunnel, 223, 435 
 
 iron supports, 255 
 
 Halkyn Mine, Flintshire, slickenside 
 at, 10 
 
 wooden pulley-frame, 395 
 Hallett, Judge, on the Aspen Case, 
 
 9 
 
 Hall's stone-breaker, 547 
 Hammer, of Mans-feld, on lifting 
 beam of pumping ei glue, 
 461 
 
 on the friction of guid--s for 
 
 pump rods in shaft, 473 
 Hammers for boring by hand, 159 
 Hanarte's air-compressor, 165 
 Hand-barrows, 375 
 Hand-drilling, 157, 160 
 Hand-picking, 541 
 Hand-power diamond drill, 123 
 
 rotary drills, 155 
 Hand-sampling, 632 
 Hand-sieves, 566 
 Hand-tools, 151 
 Hang-fire, 217 
 
 Hanging wall, definition of, 10 
 Haniel and Lueg's keps, 419 
 Halting and Hesse, on cancer of 
 
 lungs caused by dust, 686 
 Hartz blower, 493 
 
 Ernest Augustus adir, 434 
 
 foreman's lamp, 516 
 
 iron rails used as supports, 
 258 
 
 jiff, 570 
 
 miner's lamp, 515 
 
 timbering cnamber for water- 
 wheel, 241 
 
 timbering for shaft, 240 
 
 use of water power, 442 
 Harvey on the occurrence of ni- 
 trate of soda in Chili, 62 
 Hat, Cornish miner's, 671 
 
 French miner's, 671 
 
 German miner's, 672 
 
 ideal miner's, 672 
 
 iionstone miner's, 671 
 
 Mansfeld miner's, 672 
 
 Koumanian miner's, 672 
 Hatches, 389 
 Haulage, 348 
 
 electric railways, 371 
 
 endless chain, 371, 379 
 
 endless rope, 367 
 
 horses, 362 
 
 locomotive, 363 
 
 main and tail rope, 366 
 
 single-rope system, 365 
 Head gear, 394 
 
 Heat at mines, 670 
 
 of mines on Comstock Lode, 76 
 
 of workings, influence on 
 
 health, 689 
 
 Heated floors, drying on, 592 
 Heave, 88 
 
 of vein sideways caused by 
 
 slip along line of dip, 91 
 Heavy spar, bleaching of, 609 
 
 occurrence, 23 
 
 Heights (N. Lancashire), 344 
 Hepple white- Gray lamp, 521 
 Hercules powder, 214 
 Hesse's method of testing the air, 
 
 503, 505 
 
 Himmelfahrt works, loss at, 630 
 Hirnant drill, 192 
 Hirt, on prevention of illness from 
 
 arsenic, 686 
 Hitches, 154, 231 
 Hockin and Oxland calciner, 613, 
 
 6'5 
 
 Hoffman magnetic separator, 602 
 
 Hofmann kiln, 613 
 
 Hoisting, 387 
 
 Holes, arrangement of, for driving 
 and sinking, 222, 225 
 
 Hoi way Consols mine, explosion of 
 fire-damp, 476 
 
 Honigmann, soda locomotive, 364 
 
 Honningen, carbonic acid gas at, 25 
 
 Hopper of hydraulic elevator, 300 
 
 Hoppet, 408 
 
 Horned sets, 233 
 
 Horse in lode, definition of, n 
 -whim, 389 
 
 Houses, underground haulage by, 
 362 
 
 Hospitals, 695 
 
 Hot springs, 476 
 
 Hottinguer shaft, Blanchets pneu- 
 matic hoist at, 428 
 
 House, changing, 679 
 
 Housing of workmen, 673 
 
 Howard's steel sleeper, 352 
 
 Howell's steel tube prop, 266 
 
 H-piece, 451 
 
 Huanchaca silver mines, 78 
 
 Huelva, port of, 380 
 
 Hund, 351 
 
 Huntinjiton mill, 561 
 
 Hurricane lamp, 516 
 
 Hurry, 344 
 
 Husband's stamps, 551 
 
 Hushing, 106 
 
 Hydraulic cartridge, 208 
 drill, 180 
 elevator, 300 
 lock for safety lamps, 522 
 
INDEX. 
 
 729 
 
 Hydraulic continued. 
 mining, 226, 292 
 power, 171 
 
 for breaking ground, 163 
 transmission of power, 469 
 Hydrogen flame used in testing for 
 fire-damp, 500 
 
 ICE, 51 
 
 Iceland, mode of occurrence of sul- 
 phur in, 82 
 Idria, occurrence of quicksilver ore 
 
 at, 72 
 treatment of quicksilver ores, 
 
 627 
 
 Illicit Diamond Act, 677 
 Incandescent lamps in bhaft sinking, 
 
 524 
 
 portable, 523 
 
 Inclination of a level, effect of, on 
 ventilation, 485 
 
 of underground road, 355 
 Incline, natural ventilation of, 486 
 Inclined planes, accidents on, 708 
 
 underground, 362 
 
 shafts sunk on lode, 225 
 Inclines, 308 
 
 self-acting, 376 
 Indications of tire-damp, 498 
 Indicative plants, 103 
 Indicator for winding engines, 421 
 Indicators at Ballarat, 13, 16 
 Inflammable gas, 59, 476 
 Ingersoll bar-channel! er, 201 
 
 -Sergeant air-compressor, 167 
 Injection compressors, 166 
 
 of veins, 14 
 
 Intersection of veins, 1 1 
 Inversion of strata, 88 
 Inverted saddle-reefs of Victoria, 
 
 47 
 Iron and steel supports for levels, 
 
 255 
 
 shafts, 263 
 working places, 265 
 Iron-bark, 229 
 Iron hat, or gozzan, 100 
 Iron ladders, 529 
 Iron mines, Forest of Dean, method 
 
 of working, 340 
 
 N. Lancashire, method of work- 
 ing, 343 
 
 Iron ores, dressing of, 624 
 occurrence of, 51 
 Northamptonshire open work- 
 ings, 286 
 
 Iron pump-rods, Shakemantle mine, 
 
 461 
 
 Iron pyrites, Carnarvonshire, 83 
 Iron rails used for supporting roof 
 
 of level, 256 259 
 Iron rings for supporting shaft 
 
 linings, 263 
 
 Iron rods for boring, 124 
 Ironstone blows (Australia), 100 
 Ironstone, method of working in 
 
 Cleveland district, 315 
 miner's cap, 67 1 
 
 Irruptions of water into mines, 707 
 Irving on the copper veins of Lake 
 
 Superior, 36 
 Itabirite, 40 
 Italy, alabaster in, 51 
 asbestos mines of, 21 
 boric acid in, 25 
 carbonic acid gas in, 26 
 marble in, 58 
 mining law in, i, 2 
 mode of occurrence of sulphur 
 in, 82, 83 
 
 JACK, on the Mount Morgan gold 
 deposits, 48 
 
 on the outcrop of gold veins in 
 
 Queensland, 98 
 Jacobi's stove, 597 
 Jacomety and Lenicque's separa- 
 tors, 575 
 
 table, 583 
 
 trommel, 567 
 Jacotinga, 44 
 Jad, 310 
 
 Jagersfontein diamond mines, 39 
 Jan Ham's clack, 453 
 Japan, torches used in, 515 
 
 working by reflected daylight 
 
 in 5'3 
 
 Jarolimek's drill, 179 
 
 Jarrah, 228 
 
 Jars, 140 
 
 Jaw-breakers, 546 
 
 Jigger, 570 
 
 pneumatic, 589 
 
 Jiggers, discharge of, 572 
 
 Jog, 237 
 
 Johannesburg, deep boring at, 119 
 gold-bearing rocks of, 42 
 thickness of beds of auriferous 
 conglomerate 5 
 
 Joint for wooden rods. 445 
 
 Jordan's grinder, 557 
 
730 
 
 INDEX. 
 
 Jumper, 157 
 
 Junge hohe Birke mine, cage at, 
 533 
 
 KAINITE, occurrence of, 70 
 Kaiser Josef Erbstolln, Hungary, 
 
 434 
 
 Kaiser Josef II. adit, Pf ibram, 434 
 Kauri gum, searching for by 
 
 piercing, 106 
 pine, 229 
 
 Keeve, or dolly-tub, 570 
 Kendall on the geology of the Cleve- 
 land district, 41 
 on the haematite veins of the 
 
 Lake District, 7 
 
 Kennedy on the efficiency of com- 
 pressed air, 164 
 Keps, 419 
 
 Kessler, magnetic separator, 602 
 Kibble, 404 
 Kieselguhr, 213 
 Kiln, American phosphate, 594 
 fuller's earth, 595 
 Hofmann, 613 
 Kilns for drying, 594 
 Kimberley diamond district, 37 
 
 mines, compound for native 
 
 workmen, 677 
 method of working at De Beers, 
 
 Kincaid and McQueen's bucket 
 
 dredger, 175 
 Kind, free-falling tool for boring, 
 
 130 
 -Chaudron process of sinking 
 
 shafts, 271 
 
 recent modifications, 276 
 King and Humble's detaching hook, 
 
 422 
 King,on the "indicators" at Ballarat, 
 
 on the Comstock Lode, 76 
 King-post, 457 
 King's magnetic separator, 604, 
 
 606 
 
 Kitto, Paul and Nancarrow, self- 
 discharging skip, 416 
 Knots in the lead-bearing sand- 
 stone at Mechernich, 55 
 Knox system of boring holes for 
 
 rending stone, 162 
 of charging holes, 220 
 Kongsberg silver mine, fire-setting, 
 
 225 
 
 silver veins of, 12 
 Korea, fire-setting in, 225 
 
 Kreischer and Winkler on the ap- 
 pearance of the fire-damp cap, 499 
 Krom rolls, 554 
 Krom's stove, 595 
 
 LABOUE, principles of employment 
 
 of mining, 637 
 Ladder-climbing, diseases caused by 
 
 excessive, 688 
 Ladders, 527 
 iron, 529 
 Lagging, 233 
 
 Laidler's sector wire rope, 401 
 Lake Superior, copper-bearing dis- 
 trict of, 34 
 iron ores of, 54 
 
 mines, stamps used at, 551, 553 
 treatment of copper ore at, 621 
 La Louviere mine, Belgium, 467 
 Lc-mm and Franck's fireless locomo- 
 tive, 363 
 
 Lamp, electric, 523 
 flare, 516 
 
 Hartz foreman's, 516 
 Hartz miner's, 515 
 Hurricane, 516 
 magnesium ribbon, 517 
 Mansfeld, 516 
 safety, 518 
 Saxon miner's, 516 
 Scotch, 516 
 Sicilian, 515 
 United States, 516 
 Lander, 410 
 Lang's wire rope, 400 
 Larch for timbering excavations, 227 
 Lashings, 237 
 Latch and Batchelor's flattened 
 
 strand wire rope, 400 
 Lateral secretion theory of forma- 
 tion of mineral veins, 15 
 Laths, 243 
 Lawn, on searching for haematite 
 
 in the Furness district, 106 
 on working haematite in North 
 
 Lancashire, 343 
 
 Laxey mine, locomotive at, 363 
 man-engine at, 535 
 strike of lode at, 14 
 Lead lode at Wheal Mary Ann, 6 
 ores, dressing of, 624 
 modes of occurrence, 55 
 state of in gozzan, 101 
 plant, 104 
 poisoning, 687 
 
 prevention of, 687 
 rivet i'or safety lamps, 522 
 
INDEX. 
 
 Lead-bearing sandstone, Mecher- 
 
 nich, 1 8 
 
 Lead, mode of working, 320 
 Leadville, Colorado, mode of occur- 
 rence of lead ores at, 55, 57 
 Lease system in Colorado, 647 
 Leather packing for pumps, 448 
 Leats, 293 
 Leavitt stamp, 553 
 Legal definition of the term lode, 8 
 Legislation affecting mines and 
 
 quarries, 653 
 Leg, or side-prop, 232 
 Legrand's steel sleeper, 352 
 Lenneschiefer, Liiderich mine, 85 
 Lesley on the composition of natural 
 
 gas, 59 
 
 Lester's stone-breaker, 547 
 Levant Mine, changing house at, 679 
 Level, natural ventilation of end of, 
 
 485 
 use of air-sollar in ventilating 
 
 end, 487 
 Levels, driving, 222 
 
 iron and steel supports for, 255- 
 
 263 
 
 lined with masonry, 250 
 methods of timbering, 232 
 ventilating lower, 489 
 Liability Act, Employers', 666 
 Lid, 244 
 
 Lievin Company, shaft sunk by, 277 
 Lifts (Cleveland), 316 
 Lighting workings, 513 
 Lime cartridge, 208 
 Limestone, bituminous, Val de 
 
 Travers, 22 
 burning of, 611, 613 
 Lime-water test for the air of mines, 
 
 502, 503 
 
 Lindemann's apparatus, 506 
 Lining boards, 445 
 bore-holes, 131 
 tube, boring by revolving the, 
 
 117 
 
 tube for brine well, 305 
 Linkenbach, stationary table of, 581 
 Liquefaction of carbonic acid, 600 
 
 use of, in dressing, 597 
 Listings, 237 
 Lithofracteur, 214 
 Liveing's indicator for fire-damp, 
 
 500 
 Llanbradach Colliery, automatic 
 
 water-tank at, 437 
 sinking arrangements at, 408 
 steel trams at, 359 
 Loading kibble, 405 
 
 skip in shaft, 410, 412 
 
 Learning (Australia), 106 
 Lochs, definition of, 6 
 Locked coil wire rope, 382, 400 
 
 socket for, 403 
 
 Lockhart's gem separator, 577 
 Locks for safety lamps, 522 
 Locomotives for underground use, 
 
 363 
 
 for use at the surface, 378 
 Lode at Wheal Mary Ann, 6 
 definitions of, 5, 6 
 legal definition of, 9 
 modes of working, 325, 340 
 narrow, mode of working, 330 
 wide, with weak sides, mode of 
 
 working, 331 
 worked away in slices paral lei 
 
 to dip, 335 
 Lode-lights, 107 
 
 Lodes, conditions affecting produc- 
 tiveness of, 1 1 
 length of, along strike, 1 1 
 formed by alteration of the en- 
 closing rock, 7 
 wide, worked with pillars and 
 
 chambers, 338 
 Lofting, 256 
 Longwall workings for copper-shale 
 
 at Mansfeld, 322 
 
 Loose ground, supporting excava- 
 tions in, 242 
 timbering levels in, 236 
 Lorraine, iron ores of, 53 
 Loss in dressing at Churprinz works, 
 
 631 
 
 at Ems, 631 
 
 at Himmelfahrt works, 630 
 at Pestarena, 631 
 cause of, 630 
 slate, 631 
 Lovett-Finney magnetic separator, 
 
 603 
 
 Lowmoor jacket, 713 
 Lubrication of mine waggons, 358 
 Luderich zinc mine, 85 
 Lunge's apparatus for testing the 
 air of mines, 503, 505 
 
 MACGEORGE on deviation of bore- 
 holes, 148 
 Machine drills, 181 
 
 sieves, 566 
 Machinery, accidents from, 711 
 
 clothing for men engaged near, 
 
 673 
 Magnesium ribbon lamp, 517 
 
732 
 
 INDEX. 
 
 Magnetic lock for safety lamps, 522 
 separation, 600 
 
 bismuth ore with magnet- 
 ite, 606 
 
 Namaqua Copper Co., 606 
 objects of, 600 
 Queensland, 606 
 separators, 600 
 
 Ball-Norton, 603, 606 
 Buchanan, 604 
 Chase, 60 1 
 Conkling, 601 
 Edison, deflection, 606 
 
 second, 602 
 Hoffman, 602 
 Kessler, 602 
 King, 604, 606 
 Lovett-Finney, 603 
 Wenstrom, 605 
 Magnetite, dressing of, 600 
 
 jigging, 624 
 
 M^in and tail rope system of haul- 
 age, 366 
 Mttjoiiuie, Colonel, on the effect of 
 
 oil on safety fuse, 217 
 Malay Peninsula, tin-bearing alluvia 
 
 of, 85 
 Mallard and Le Chatelier on testing 
 
 for fire-damp, 500 
 Mallet, or sledge, 154, 159 
 Man-engine, 534 
 
 accidents on, 705 
 Manganese ore, dressing of, 625 
 
 occurrence of, 57 
 Man -f eld copper-mines, 29 
 adit at, 434 
 
 barracks for workmen, 674 
 compound pumping engine, 
 
 Ernst IV. shaft, 443 
 corn pound pumping engine, 
 
 Otto IV. shaft, 444 
 cross-cut lined with concrete, 
 
 251 
 
 descent and ascent of men, 532 
 
 employes living in own houses, 
 679 
 
 hydraulic counterpoise to pump 
 rods, 458 
 
 lamp used at, 516 
 
 man-engine at, 536 
 
 method of working copper- 
 shale, 322, 325 
 
 miner's hat, 672 
 
 pick used at, 153 
 
 Kittinger pump at, 456 
 
 thickness of bed of copper- 
 shale, 5 
 
 treatment of copper ore at, 
 621 
 
 Mansfeld copper-mines continued. 
 
 underground air reservoirs at, 
 169 
 
 underground pumping engines 
 
 at, 467 
 Marble, 58 
 
 Maros-Ujvar, arc-lamp at, 524 
 Marsaut lamp, 521 
 Marsden's pulveriser, 547 
 
 stone-breaker. 547 
 Marshall, discovery of gold in 
 
 California by, 94 
 Marsh gas, found in mines, 476 
 Marston Hall mine, 311 
 Marvin drill, 198 
 Masonry, for lining levels, 249 
 
 shafts, 252 
 
 dam in shafts, 433 
 Masses, or non-tabular deposits of 
 minerals, 18 
 
 methods of working, 340 
 Matai wood, 229 
 Mather and Platt's system of boring, 
 
 142 
 
 Mathet, joint for air-mains, 170 
 Matrix, definition of, 1 1 
 Maul, 141 
 Measure, payment by, 638, 639, 640 
 
 and time, payment by, 641 
 Measuring the quantity and press- 
 ure of air in mines, 506, 512 
 
 staff, 231 
 Meat earth, 286 
 Mechanical picks, 199 
 
 processes of dressing, 538 
 
 ventilation, 491 
 Mechernich, arc-lamp at, 524 
 
 barracks for miners, 674 
 
 dressing lead ore at, 625 
 
 friability of ore, 607 
 
 jumper used at, 157 
 
 lead-bearing sandstone of, 5, 
 
 method of working lead-bearit g 
 
 sandstone, 320 
 opencast, 289 
 pumping engines at, 467 
 siphon separator used a,r, 579 
 Medical attendance, deduction for, 
 
 639 
 
 Medium fan, 498 
 Mercurial poisoning, symptoms of, 
 
 688 
 vapour in quicksilver mines, 
 
 480 
 
 Metales frios, or unchanged sul- 
 phides, 101 
 
 Metallic supports for excavations, 
 255 
 
INDEX. 
 
 733 
 
 Metalliferous Mines Regulation Acts, 
 
 656 
 
 accident statistics, 700, 701 
 Mica, dressing of, 625 
 
 mode of occurrence of, 58 
 Middlesbrough, extraction of salt 
 
 by bore-holes, 305 
 marsh-gas with brine, 476 
 Mill, Chilian, 557 
 Huntington, 561 
 Sturtevant, 563 
 Close lead mine, Derbyshire, 
 
 explosion of fire-damp, 476 
 Mills for grinding, 556 
 
 or passes, 330 
 Mine, atmosphere of, 475 
 definition of, I 
 derivation of word, I 
 Miner, clothing of, 669 
 condition of, 669 
 regulations for benefit of, 655 
 Minera zinc mine, Wrexham, 86 
 Mineral deposits, classification of, 3 
 repositories, anomalies in, 17 
 veins, connection of, with faults, 
 
 89 
 
 formation of, 14 
 Minerals, ownership of, 653 
 Minero bird at Caralal, 105 
 Miners' cottages, 677 
 housing, 673 
 inch, definition of, 301 
 Minette, 53 
 
 Minieres, definition of, i 
 Mining, comparative healthiness of, 
 
 683 
 
 definition of, I 
 
 labour, principles of employ- 
 ment of, 637 
 law, in France, I 
 in Italy, 1 , 2 
 
 in the United Kingdom, i 
 in the United States, 8, 9 
 statutes, 656 
 
 relating to Derbyshire, 655 
 to Forest of Dean, 655 
 subdivision of the subject, 2 
 Miscellaneous pulverisers, 563 
 Mispickel, treatment of, 611, 612, 
 
 613, 619 
 Miss-fire, 217 
 
 danger from, 213 
 Moil, 231 
 Molinello, 618 
 Mona and Parys mines, cobbing at, 
 
 545 
 Monier system of using concrete, 
 
 254 
 Monitor, 296 
 
 Montana, copper deposits of, 37 
 Monte Catini, flora of, 104 
 Monteponi, Sardinia, adit at, 435 
 
 roasting calamine at, 615 
 Moore, pumps worked underground 
 
 by hydraulic power, 469 
 Moravia, dressing of graphite in, 
 
 623 
 Mortality, comparative figures, 683, 
 
 684 
 
 Moss-box, 273 
 Mother Lode or " Great Quartz 
 
 Vein," California, 45 
 Motion of particles in water, 568 
 Mount Bischoff, dressing tin ore at, 
 
 630 
 
 Morgan gold mine, 48, 97 
 Mountfield gypsum mine, Sussex, 
 
 437 
 
 Mueseler's lamp, 520 
 
 Mulberry mine, near Bodmin, 19 
 mode of working, 290 
 
 Murgue, on the resistance to air- 
 current due to sides of airway, 
 5" 
 
 NAMAQUA COPPEK Co., magnetic 
 
 separator used by, 606 
 Names of places, information 
 
 afforded by, no 
 Natural gas, conveyance by pipes, 
 
 373 
 
 occurrence of, 59 
 Natuial ventilation, 482 
 Needle, 161 
 
 Neu-Stassfurt mine, electric rail- 
 way, 371 
 Nevada, Comstock lode, 76 
 
 mineral deposits at Steamboat 
 
 Springs, 75 
 New Alrnaden, California, 73 
 
 Brunswick, antimony ore in, 21 
 Caledonia, cobalt ore in, 28 
 
 nickel ore in, 60 
 Idria. working by reflected day- 
 
 Ightat, 513 
 South Wales, alunite in, 20 
 
 tin-bearing alluvia of, 85 
 Zealand, trees used for mining 
 
 purposes, 229 
 Nickel ore, discovery of, in New 
 
 Caledonia, 99 
 
 ores, mode of occurrence of, 60 
 Nitrate of soda, mode of occurrnce 
 
 of, 62 
 
 mode of working, 286 
 preparation of, 608 
 
734 
 
 INDEX. 
 
 Nitrate mixtures (explosives), 210 
 Nitro-cellulose, 215 
 Nitrogen in mines, 479 
 Nitro-glycerine, 211 
 
 products of explosion of, 212 
 Noble and Abel, on fired gunpowder, 
 
 209 
 Noetling, on the oil-fields of Bur- 
 
 mah, 66 
 Nog, 232 
 
 Nolten, on finding deviation of bore- 
 holes, 148 
 
 Northampton, deep boring at, 118 
 Northamptonshire, mode of working 
 
 iron ore, 286 
 
 North Lancashire, dressing haema- 
 tite in, 624 
 
 working haematite deposits, 343 
 
 royalties in, 654 
 North Wales, iron pyrites, 83 
 
 slate mines, 312 
 
 washing pit used in, 539 
 North wich, salt beds of, 75 
 Nunnery Colliery, steel beams, 256 
 Nystagmus, 688, 689 
 
 OAK for timbering excavations, 227 
 Ochre at Parys mine, 616 
 
 dressing of, 626 
 
 Ochsenius, on the origin of the 
 nitrate deposits of South America, 
 
 63 
 
 Oeynhausen's sliding joint, 128 
 Ogle, Dr., on annual death-rates in 
 
 various trades, 683, 684 
 Ohio, mode of occurrence of natural 
 
 gas in, 59 
 
 Oil, effect of on safety fuse, 217 
 fields of Baku, 65 
 of Burmah, 65 
 of the United States, 67 
 Oil-wells, gases met with in sinking, 
 
 477 
 
 Oils used in lamps, 515, 516, 519 
 Olaf Terp, use of emery for boring, 
 
 124 
 
 Open-fire drying, 592 
 Open works, 285 
 Optimus drill, 189 
 Ormerod's detaching link, 416 
 Osceola Co.'s mine, arc-lamp at, 525 
 Otago, New Zealand, lodes of, 8 
 Otto's system of aerial ropeway, 
 
 382 
 
 Outcrop of lodes, 98 
 Overburden, 286 
 
 Overhand stoping, 329 
 
 advantages of, 331 
 Overlap fault, 90 
 Overwinding, 422 
 Ovuli, 51 
 
 Ownership of minerals, 653 
 Oxygen, absorption of, 4^0 
 
 determination of, in the air, 
 506 
 
 necessity for a large proportion 
 
 of, 505 
 Ozokerite, dressing of, 626 
 
 extraction of, by benzine, 609 
 
 mines, Boryslaw, inflammable 
 gases at, 477 
 
 mode of occurrence of, 63 
 
 purification of, 598 
 
 PACKING plunger pump, 452 
 
 pump bucket, 448 
 Pacos (S. America), 100 
 Pan> for amalgamating gold ores, 
 
 622 
 for grinding and amalgamating, 
 
 556 
 
 for prospecting, 538 
 Paragenesis of minerals, 97 
 Parian cement, 613 
 
 preparation of, 624 
 Parodi on the Sicilian sulphur beds, 
 
 83 
 Parys mine, extraction of copper by 
 
 solution, 307 
 precipitation at, 616 
 Pass, 332 
 
 best form of, 348, 349 
 Patterson's stamps, 551 
 Paxman's roller for Huntington 
 
 mill, 561 
 Pay-bill for payment by measure, 
 
 638 
 
 value of product, 642 
 weight, 640 
 Pay-lead, 318 
 
 Payment by measure, 638, 639, 640 
 time, 637 
 
 time and measure, 641 
 value of product, 641 
 weight, 639 
 
 Pearce, on the tin-lodes of Corn- 
 wall, 7 
 Peeker, 222 
 
 Penhall's mine, Cornwall, succes- 
 sion of faults at, 92 
 Penrhyn slate quarry, 288 
 Pensions, 693 
 
INDEX. 
 
 735 
 
 Percolation of surface water into 
 
 workings, 429 
 Percussion tables, 584, 589 
 Perpendicular shafts, advantages 
 
 of, 325 
 
 Pestarena, loss of gold at, 631 
 Petroleum, 65, 66 
 
 conveyance by pipes, 374 
 extraction by wells, 304 
 Petroleum engine, 163 
 for pumping, 445 
 for working drill, 180 
 Pettenkofer, on the limit of carbonic 
 
 acid in air, 502 
 
 Phenolphtbalein, use of, in lime- 
 water test, 502 
 Phillips, on the mica of North 
 
 Carolina, 58 
 
 Phosphate kiln, American, 594 
 Phosphate of lime, 67, 69 
 
 discovery of, at Beauval, France, 
 
 94 
 
 in South Carolina and Florida, 
 68,69 
 
 search for, by piercing, 107 
 
 treatment of, 626 
 
 weathering of, 6n 
 Photometric tests of light given by 
 
 safety lamps, 519, 520 
 Physical properties, dressing pro- 
 
 cesses depending on, 568 
 Pick and gad work, 154 
 
 handles, 153 
 Picking by hand, 541 
 Picks, 152 
 
 mechanical, 199 
 
 sharpening, 153 
 
 with separate blades, 153 
 Picric acid, explosives containing, 
 
 215 
 
 Pieler lamp, 499 
 
 testing for fire - damp with 
 
 hydrogen flame, 500 
 Piercing, 106 
 Pigsty timbering, 245 
 for levels, 234 
 ^for shafts, 239 
 Pilar, on Franke's mechanical chisel, 
 
 199 
 Pillaring of slate, 81 
 
 plane, 314 
 Pillars and chambers, working wide 
 
 lodes with, 338 
 
 left as permanent supports, 309 
 worked away, 315 
 Pine, varieties used for mining 
 
 purposes, 227, 228 
 Pipe- lines, 374 
 Pipes, conveyance of minerals by, 349 
 
 Pipes continued. 
 
 for compressed air, 170 
 
 for conveying water, 295 
 
 for pump column, 450 
 
 wooden, 450 
 Pitch lake of Trinidad, 22 
 
 of a shoot of ore, definition of, 
 ii 
 
 purification of, 598 
 
 pine, 227 
 
 Pit-head frame, 394 
 Plane tables, 579 
 Planing machines, 565 
 Plank tubbing for shafts, 266 
 Plants, indications of minerals 
 
 afforded by, 103 
 Plaster of Paris, 613 
 
 preparation of, 624 
 Plat, 405 
 
 Plug and feathers, 2o3 
 Plumbism, 687 
 Plunger pump, 45 1 
 Plutonic rocks, 3 
 Pneumatic hoisting, 427 
 
 jig, 589 
 
 Poetsch's freezing process, 281 
 Pohl6 pump, 470 
 Points and crossings, underground, 
 
 354 
 
 Poling, 236 
 Pollution Prevention Act, Rivers, 
 
 667 
 Pontgibaud lead mines, carbonic 
 
 acid at, 475 
 Poppet heads, 394 
 Post, 237 
 Potassium salts, deposits at Stass- 
 
 furt, 70 
 discovery of, at Stassfurt, 
 
 96 
 
 method of mining, 315 
 treatment of, 627 
 Potosi, 78 
 Precipitation, 616 
 Premiums for good conduct, 652 
 Preparation of ores. See DRESSING, 
 
 Preservation of timber, 229 
 Pressure of air, influence on health, 
 689 
 
 box, 295 
 Pricker, 161 
 Piibram, deep shafts at, 404 
 
 underground fire at, 708 
 Priestman's grab dredger, 176 
 Principles of employment of mining 
 
 labour, 637 
 Prop, 244 
 Props, iron and steel, 265 
 
736 
 
 INDEX. 
 
 Prospecting, or search for minerals, 
 
 93 
 
 by the diamond drill, 119, 123 
 by the diamond drill, cost of, 
 
 122 
 
 Prospector, qualifications of, 112 
 
 Provident societies, 690 
 
 Prussia, accidents from man-engines, 
 
 705 
 Puddling machine, Australia, 539 
 
 Pulley-frame, 394 
 Pulleys, 397 
 Pulsator, 622 
 Pulsometer, 468 
 Pulveriser, Cyclone, 563 
 
 Marsden's, 547 
 Pulverisers, miscellaneous, 563 
 
 pneumatic, 563 
 Pump column, 450 
 
 for extracting brine from bore- 
 hole, 306 
 
 lifting, 448 
 
 plunger, 451 
 
 plunger, advantages of, 452 
 
 Pohle, 470 
 
 pulsometer, 468 
 
 Riedler, 467 
 
 Rittinger, 454 
 
 rods, 445 
 
 counterbalancing, 457 
 iron, 461 
 
 valves, 453 
 Pumping engines, compound, 443- 
 
 445 
 
 duty of, 472 
 
 placed underground, 466 
 single acting, 443 
 machinery, moving heavy parts 
 
 of, 461 
 
 plant, Shakemantle mine, 461 
 Pumps, drainage by, 441 
 
 driven compressed air or elec- 
 tricity, 470 
 
 drowning of, 450, 446, 467 
 wooden, 450 
 worked by hydraulic power, 
 
 469 
 Purifying water from dressing 
 
 works, 667 
 Pyrites, Carnarvonshire, 83 
 
 mode of working in North 
 
 Wales, 309 
 
 worked opencast, Rio Tinto, 
 289 
 
 Q 
 
 QUARRIES, definition of, i 
 
 raising stone from open, 406 
 
 Quarries continued. 
 
 slate, North Wales, 312 
 underground sjate, Ardennes, 
 
 3*4 
 
 stone, Bath, 310 
 Quarry Fencing Act, 667 
 Quartering, sampling by, 633 
 Quenast quarries, premiums for good 
 
 conduct, 652 
 Quicksand, Haase process of sinking 
 
 in, 283 
 Poetsch process of sinking in, 
 
 283 
 Triger's process of sinking in, 
 
 277 
 Quicksilver, chance discovery of, in 
 
 California, 94 
 mines of California and Nevada, 
 
 Becker on, 16 
 
 mines, unhealthiness of, 687 
 ore, occurrence of, 71 
 ore, treatment of, 627 
 rock, 74, 103 
 
 B, 
 
 RACK-A-ROCK, 211 
 
 Ragging, 544 
 Rails, 351 
 
 Railways, electric, 371 
 surface, 376 
 underground, 351 
 Rammelsberg Mine, Hartz, pyrites 
 
 deposit, 32 
 
 Rand, gold output, 43 
 Ratchet drill, 155 
 Rating Act, 655 
 
 Raymond, on indicative plants, 104 
 Recreation, 696 
 
 Red clay of New Caledonia, 28, 60 
 Red bar (Johannesburg), 103 
 Redonda, phosphate of alumina at, 
 
 69 
 
 Red River, tin ore got from, 630 
 Reflected daylight, working by, 
 
 5 : 3 
 
 Regulations for mines, working, 655 
 Regulations. See ACTS, 656 
 Reservoirs for compressed air, 168 
 for hydraulic mining purposes, 
 
 293 
 
 Resistance to air-current, 510-512 
 Restronguet creek, dressing of tin 
 
 ore at, 629 
 method of working tin-bearing 
 
 gravel, 316 
 occurrence of tin- ore in alluvium 
 
 of, 85 
 shaft sinking at, 268 
 
INDEX. 
 
 737 
 
 Reticulated masses, 19 
 Retorting amalgam, 600 
 
 sulphur ores, 600 
 Returning charges, 642 
 Reumaux's automatic speed checker, 
 
 425 
 
 Revolving round table, 583 
 Reversed fault, 90 
 Rewarewa. 229 
 
 Rhosesmor mine, Flintshire, 435 
 Rice's clutch, 369 
 
 Richness of lodes, conditions affect- 
 ing, ii 
 
 Richmond v. Eureka case, 8 
 Rickard, on Mount Morgan mine, 
 
 Queensland, 49 
 on the saddle-reefs of the Ben- 
 
 digo gold-field, 47 
 Riebeck's stove, 595 
 Riedler pumps, 467 
 Riffles, 299 
 Rigg and Meiklejohn's machine, 
 
 203 
 
 Rinchiusu, 475 
 Rio Tinto, arc- lamp at, 525 
 character of ore at, 33 
 geology of the district, 31 
 gozzan, 33 
 lodes at, 32 
 mines, shipping arrangements 
 
 at Huelva, 380 
 opencast, 289 
 pillar and chamber workings, 
 
 338 
 
 precipitation at, 616 
 timbering for levels, 233 
 treatment of copper ore at, 
 621 
 
 Rise, difficulty of ventilating, 486 
 mode of ventilating, 488 
 
 Rises, method of timbering, 344 
 
 Rittinger, fall of spheres in water, 
 568 
 
 Rittinger pump, 445, 454 
 
 Rittinger's percussion table, 584 
 
 Rivers Pollution Prevention Act, 
 667 
 
 Rivers, sinking shafts in, by freezing, 
 280 
 
 Roasting, 611, 613 
 
 Roberts, C. Warren, sleeper, 353 
 
 Roburite, 215 
 
 fumes from explosion of, 481 
 
 Rock-boring competition, 159 
 
 Rock-drills, 177 
 
 Rock-salt at Stassfurt, 70 
 
 Rods for man-engines, 535 
 for pumps, 445 
 
 Rolland's fireless locomotive, 363 
 
 Rolls, Cornish, 553, 554 
 
 Krom, 554 
 Roof of a bed, definition of, 5 
 
 slate mining, 312, 313 
 Root's blower, 494 
 Rope haulage, 365 
 
 preventing bhock to, in winding, 
 427 
 
 socket, 139, 140 
 Ropes for winding, steel, 399 
 
 modes of capping, 402 
 
 testing, 427 
 
 Rossigneux system of counterbalanc- 
 ing, 459 
 Rotary machine drills, 178 
 
 washing machine for diamonds, 
 
 540 
 Rothliegendes in Mansfeld district, 
 
 29 
 
 Rothschonberger Stalin, 434 
 Roumania, salt mines, 312 
 Roumanian miner's hat, 672 
 Round tables for picking, 542 
 
 for sluices, 58? 
 Rowoldt's stove, 597 
 Royalties, 654 
 
 sliding scale for, 654 
 Ruelle's stove, 596 
 Ruins, indications afforded by, 109 
 Running loop, 447, 
 Russia, manganese ores of, 57 
 
 occurrence of quicksilver in, 
 
 Ry land's glass-lined pipe, 171 
 
 SABOT, 673 
 
 Saddle reefs, Victoria, 47 
 
 Safety catches, 426 
 
 on cage, 418 
 fuse, 217 
 gear for hauling men at Bory- 
 
 slaw, 531 
 
 lamp, used for testing for fire- 
 damp, 499 
 lamps, 518 
 
 St. Agnes, Cornwall, tin lodes of, 84 
 St. Day mines, heat at, 670 
 Saint-Etienne, mine-waggon used 
 
 at, 358 
 
 St. Just, strike of lodes at, 14 
 Salisbury Mine, Johannesburg, 42 
 Salt, discovery of in Cleveland 
 
 district, 96 
 
 excavating by water, 226 
 extraction by wells and bore- 
 holes, 304 
 
 3 A 
 
73* 
 
 INDEX. 
 
 Salt continued. 
 
 minerals associated with, 97 
 mines, Cheshire, 311 
 Eoumania, 312 
 occurrence of, 75 
 preparation of, 628 
 workings for at Bex, 307 
 works affected by Alkali Acts, 
 
 665 
 Salzkammergufr, mode of working 
 
 salt-marl, 307 
 Sampling by hand, 632 
 quartering, 633 
 taking out j-mall lots, 632 
 trenching, 632 
 object of, 632 
 machine, Bridgman's, 635 
 Brunton's, 635 
 Clarkson's, 634 
 Colorado, used in, 634 
 shovel, 633 
 Sandals, 673 
 San Domingos, 34 
 Sand-pump, 140 
 Sand-reel, 139 
 Sandstone, bituminous, California, 
 
 22 
 
 interstitial space in, 18 
 lead- bearing, Mechernich, 5, 18 
 silver-bearing of Utah, 18 
 Sarrau and Vieille, on the decompo- 
 sition of certain explosives, 212 
 Savage mine, heat at, 670 
 Sawing machines for stone, 564 
 Saws, circular, use for undercutting, 
 
 202 
 
 for cutting stone, 154 
 timbermen's, 231 
 used in getting freestone, 310 
 wire, 204 
 
 Sawyer on underset of props in in- 
 clined beds, 244 
 Saxon gad, 154 
 
 miner's lamp, 516 
 Schaffer and Budenberg's speed 
 
 indicator, 533 
 Schiele fan, 497 
 Schools, 682 
 Schrader on Franke's mechanical 
 
 chisel, 199 
 Schulz's stove, 597 
 Scotch fir, 228 
 lamp, 516 
 
 Scotchman's United mine, core- 
 hole at, 148 
 Scraper, 160 
 Screening, 566 
 Screw-conveyors, 375 
 Seams, 18 
 Seasoning of timber, 230 
 
 Sector wire rope, 401 
 
 Securite, 215 
 
 Sediment-tube for diamond drill, 
 
 119 
 Self -discharging skips, 412 
 
 advantages of, 417 
 Self-oiling pedestals, 361 
 Selvage, definition of, 1 1 
 Separator, Frongoch, 576 
 
 Jacomety and Lenicque's, 575 
 Lockhart's gem, 577 
 siphon, 577, 579 
 
 Separators, upward current, 574 
 Sergeant drill, 193 
 
 groove-cutter, 199 
 Serpentine, occurrence of asbestos 
 
 in, 21 
 
 occurrence of nickel in, 61 
 Sets or frames, 234, 236 
 Seyssel, France, bituminous lime- 
 stone of, 22 
 treatment of asphalt rock of, 
 
 598 
 Shaft accidents, 705 
 
 arrangement of pumps in, 451, 
 
 461, 464, 465 
 linings of iron, 263 
 natural ventilation of, 486 
 rolls, 446 
 use of air-pipe for ventilating, 
 
 488 
 Shafts, cost of sinking in watery 
 
 strata, 271 
 crooked, arrangement of pump 
 
 rods in, 446 
 deep, at Pribram, 404 
 freezing process of sinking, 
 
 278 
 
 for working mineral deposits, 308 
 for working veins, 325 
 Kind-Chaudron process of 
 
 sinking, 271 
 
 lined with concrete, 253 
 lined with masonry, 252 
 natural ventilation by two, 
 
 483 
 Poetsch's freezing process for 
 
 sinking, 281 
 
 sunk by boring process, time 
 required, 277 
 timbering of, 236 
 Shaft- sinking, 225 
 
 by incandescent lamps, 524 
 through bed of river, 268 
 Shakemantle Mine, pumping plant 
 
 at, 461 
 Shanks' system of treating caliche, 
 
 608 
 
 Shaw's apparatus for testing for 
 fire-damp, 501 
 
INDEX. 
 
 739 
 
 Shcba Mine, Barberton, 44 
 
 Gold Mine, aerial ropeway at, 
 
 384 
 
 Shell pump, 128 
 Shipping ores, arrangements for, 
 
 38o 
 
 Sheading, 105 
 Shoad-stones, 106 
 Shoe of stamps, 549 
 
 wooden, 673 
 
 Shoot of ore, definition of, n 
 Shoots, 348, 373 
 
 mouth for regulating dis- 
 charge of, 413 
 Shovel, 151 
 Shower-bath for miners, Anzin, 
 
 68 1 
 Siberia, freezing method of sinking 
 
 pits, 278 
 
 Sicilian miner's lamp, 515 
 Sicilian mines, steps for descent or 
 
 ascent, 527 
 
 Sicily, modes of working sulphur- 
 bearing limestone, 321 
 occurrence of sulphur in, 82 
 Sickness, 683 
 Side holes, 310 
 
 Sidings, endless rope system, 370 
 Sieves, 566 
 Signalling, 420 
 
 from cage, 533 
 Sill, 233 
 
 Silver, chance discoveries of, 95 
 Silver ores, occurrence of, 76 
 Broken Hill, N.S.W., 78 
 Calico, California, 79 
 Comstock Lode, Nevada, 76 
 Eureka Richmond, Nevada, 76 
 Huanchaca, Bolivia, 78 
 Kongsberg, Norway, 12 
 Stormont, Utah, 79 
 treatment of, 628 
 Silver-bearing sandstone, Utah, 18 
 Simultaneous fuse, 220 
 Single-rope haulage, 365 
 Sink, 222 
 Sinker-bar, 139 
 Sinking by compressed air method, 
 
 influence on health, 689 
 Kind-Chaudron method, 271 
 Poetsch, or freezing method, 
 
 281 
 
 shafts, 225 
 through watery strata, cost of, 
 
 271 
 
 Triger's method, 277 
 Siphon, draining mines by, 437 
 Siphon separator, 577 
 Skertchly on the mining and knap- 
 ping of flint, 41 
 
 Skip, 404, 410 
 
 loading in shaft, 410, 412 
 self-discharging, De Beers in- 
 clined shaft, 412 
 for perpendicular shaft, 415 
 Skutterud, cobalt ore, 27 
 Slug-heaps, indications afforded by, 
 
 1 08 
 
 Slate, charging holes for rending, 219 
 circular saws used for, 564 
 dressing machines, 565 
 loss in dressing, 631 
 loss in mining, 314 
 methods of working, 312-315 
 Mines (Gunpowder) Act, 659 
 occurrence of, 79 
 planing machines for, 565 
 preparation of, 628 
 splitting of, 545 
 Sledges, 3 ;o, 375 
 Sleepers, steel, 352 
 Slickensides, 10, 89 
 Slide, 88 
 
 Slides for descent, 527 
 Sliding joint, Oeynhatasen's, 128 
 Sliding scale for roy allies, 654 
 Slip, 473 
 Slopes, 308 
 Sludger, 128 
 S uices, 297 
 
 Smith, Dr. Angus, on the candle- 
 test, 501 
 on the pollution of the air in 
 
 mines, 480 
 on the pioportion of oxygen in 
 
 respirable air, 506 
 process of testing air, 502 
 Lichard, on the gold-bearing 
 conglomerate of the Trans- 
 vaa., 42 
 
 Snell, on miners' nystagmus, 689 
 Snore-piece. 448 
 
 Snow, disappearance of, from out- 
 crop of lode, 1 08 
 Societies, provident, 690 
 Sockets, joining two ropes by, 494 
 Solepiece, 233 
 Solfatara of Pozzuoli, sulphur from. 
 
 82 
 Solution, extraction of minerals by, 
 
 305 
 
 preparation of borax by, 608 
 nitrate of soda by, 608 
 potassium chloride by, 608 
 Somme department, occurrence of 
 phosphate of lime in, 68 
 treatment in, 627 
 Somonostro, endless chain haulage, 
 
 379 
 
 self-acting incline, 376 
 
740 
 
 INDEX. 
 
 Sorby, on the origin of the Cleve- 
 land ironstone, 18, 53 
 Sores produced by arsenious acid, 
 
 686 
 
 Sough, 433 
 
 Sounding, testing ground by, 705 
 Sources of mineral supply in British 
 
 Isles, 655 
 South Africa, discovery of diamonds 
 
 in, 93 
 
 dressing of diamonds, 621 
 gold ore deposits, 41 
 South Carolina, phosphate beds, 68 
 treatment of phosphate of lime 
 
 in, 627 
 South Staffordshire Mines Drainage 
 
 Commission, 474 
 Space required per head, in rooms, 
 
 676 
 Spain, cupreous pyrites deposits of, 
 
 31-34 
 
 occurrence of quicksilver in, 72 
 Spalling, 544 
 
 Spathose ore, calcination of, 612 
 Spear-rod, 445 
 Speed indicator for winding engine, 
 
 533 
 
 Spiaer (candle-holder), 515 
 Spiles, 345 
 
 Spilling, or spiling, 236, 242 
 Spiral drum, 393 
 Splitting air-current, 510 
 
 slate, 545 
 
 Sprague electric diamond drill, 180 
 Sprengel type of explosives, 215 
 Spring stamps, 551 
 Spruce fir, 228 
 
 Square-set system of timbering, 246 
 Squib, 218 
 Stalls, 309 
 Stamps, gravitation, 548 
 
 pneumatic, 551 
 
 spring, 551 
 
 steam-hammer, 551 
 Standards for wire ropeways, 382 
 Stanley's tunneller, 207 
 Stannaries Act, 668 
 Stapff, on prospecting for phos- 
 phorite, 104 
 
 Stassfurt, discovery of potassium 
 salts at, 96 
 
 occurrence of potassium salts 
 at, 70 
 
 preparation of salts at, 608 
 
 salt mines, sulphuretted hydro- 
 gen at, 479 
 
 treatment of potassium ?alts,627 
 
 workings for carnallite, 3 1 5 
 Stationary engines for haulage, 364 
 
 table of Linkenbach, 581 
 
 Statutes affecting mines or quarries, 
 6 56, 659, 662, 665 
 
 Mining, 656 
 
 See ACTS OF PARLIAMENT, 655 
 Steamboat springs, Nevada, 75 
 bteam digger, 173 
 
 engines for winding, 390 
 
 hammer stamps, 551 
 
 jet for ventilating, 492 
 
 process for sulphur, 600 
 
 shovel, 173 
 
 stove, 597 
 Steavenson twist drill driven by 
 
 power, 1 80 
 
 Steel beams used for supporting 
 levels, 256, 258 
 
 car wheels, 357 
 
 frames for levels, 259 
 shafts, 263 
 
 mine-waggons, 356, 360 
 
 props for working places, 266 
 
 pump rods, 445 
 
 sleepers, 352 
 
 wire-ropes, 399 
 Stein's endless belt, 586 
 Stelzner, on the lateral secretion 
 
 theory, 15 
 Stempels, 240, 329 
 Step-fault, 88 
 Steps for descent and ascent, 526 
 
 or stopes in open works, width 
 
 of, 286, 288, 289 
 Stockworks, 19 
 
 quicksilver ore, 73 
 
 silver ore, 79 
 
 tin ore, 19, 84 
 
 zinc ore, 87 
 Stokes' alcohol-reservoir for safety 
 
 lamp, 500 
 Stone, preparation of, 628 
 
 breakers, 546 
 Stoping, overhand, 329 
 
 underhand, 327 
 Stoves, for drying, 594 
 
 Jacobi's, 597 
 
 Krom's, 595 
 
 Eiebeck's, 595 
 
 Kowoldt's, 597 
 
 Euelle's, 596 
 
 Schulz's, 597 
 
 steam, 597 
 
 Strapping plate", 445 
 Stratified deposits, 4 
 Straw for firing shots, 218 
 Stream works, tin ore, 85 
 Strength of explosives, 216 
 Stretcher-bar, 197 
 Stretchers, 713 
 Strike, definition of, 5 
 
 miluenceofchangeof,onveins,i3 
 
INDEX. 
 
 74E 
 
 Stringy bark, 229 
 Struve's ventilator, 494 
 Studdles, 237, 243 
 Stull, 327 
 
 Sturgeon on the efficiency of com- 
 pressed air, 164 
 Sturtevant Mill, 563 
 Styria, graphite in, 50 
 Sublimation, formation of veins by, 
 
 17 
 
 Sub-Wealden boring near Battle, 96 
 Suction dredge, 177 
 
 pipe for brine well, 306 
 
 pumps, 448 
 Sudbury, discovery of nickel ore at, 
 
 94 
 
 nickel ores of, 61 
 Suffocation by gases, 707, 710 
 Sulphate of iron used for preserving 
 
 timber, 231 
 
 Sulphur, distillation of, 600 
 liquation of, 598 
 mode of occurrence of, 81 
 preparation of, 629 
 rock, Sicily, fire-damp emitted 
 
 by, 47.8 
 Bank Mine, California, 74 
 
 discoverv of quicksilver at, 
 
 96 
 
 gas from hot springs, 476 
 bearing limestone in Sicily, 
 
 82 
 
 mode of working, 321 
 seams, outcrop of, 102 
 Sulphuretted hydrogen in mines, 
 
 479 
 
 Sulphurous acid in mines, 479 
 Sump, 326 
 
 Supporting excavations, 227 
 Surface accidents, 711 
 drainage, 429 
 
 indications guiding the pros- 
 pector, 97 
 
 Surveying bore-holes, 147 
 Surveys, danger from inaccurate, 
 
 707 
 Sussex, preparation of gypsum, 
 
 624 
 
 Sussmann electric lamp, 523 
 Sutro Tunnel, Nevada, 436 
 Swab-stick, 160 
 Swage, 181 
 Sweden, iron ores of, 54 
 
 occurrence of zinc ore in, 87 
 searching for iron ore with the 
 
 magnetic needle, 112 
 Switzerland, workings for salt, 
 
 307 
 
 Sword, 448 
 Synclinals, 47, 8y 
 
 TABLES, Jacomety and Lenicque's, 
 
 583 
 
 Linkenbach's, 581 
 
 percussion, 584, 589 
 
 picking, 542 
 
 plane, 579 
 
 revolving round, 583 
 
 Kittinger's percu&sion, 584 
 
 round, 581 
 Tabular deposits, 5 
 Tachometer, 533 
 Taeglichsbeck's report on housing 
 
 of miners, 674, 679 
 Tagieff s spouting oil-well, Baku, 65 
 Tailings, 243, 588 
 
 Tamarack copper mine, Lake Supe- 
 rior, 36, 37 
 Tamping bar, 160 
 
 charge, 217 
 Tapering ropes, 404 
 Taxation of mines, 625 
 Tasmania, dressing tin ore in, 630 
 Teague's aspirator, 493 
 
 noiseless valve, 453 
 Teel's Marsh, borax deposit, 23 
 Telephones used for signalling in 
 
 mines, 421 
 Temper screw, 140 
 Temporary dam, 433 
 Testing air of mines, 498-510 
 
 ropes, 427 
 
 Thames gold-field, New Zealand, 13 
 Tharsis, pyrites mines, 34 
 Thawing dynamite, 213 
 Thickness of bed, measurement of, 5 
 Thrift, 690 
 Throw, or heave, 88 
 Throw of a fault, definition of, 89 
 
 mode of determining amount 
 
 of, 89 
 
 Timber, decaying, affects air of mine, 
 480 
 
 kinds used underground, 227 
 
 preservation of, 229 
 
 seasoning, 230 
 
 supports compared with steel, 
 
 257 
 
 used in Australia, 228 
 in England, 227 
 in United States, 228 
 withdrawing, from rubbish, 
 
 Foxdale, 338 
 
 Timbering in loose ground, 242 
 levels, 232 
 
 pigsty system, 234, 239, 245 
 shafts, 236 
 
 special excavations, Hartz, 241 
 square-set, 246 
 working places, 244 
 
742 
 
 INDEX. 
 
 Time occupied in descent and 
 ascent at Mansfeld, 532 
 
 payment by, 637 
 
 and measure, payment by, 641 
 Tin ore, alluvial deposit at Re- 
 stronguet Creek, 316 
 
 calcination of, 612, 613 
 
 dressing of, 629 
 
 lodes in granite, 7 
 
 mines affecttd by Alkali Acts, 
 665 
 
 mode of occurrence of, 83 
 
 separation from copper ore, 609 
 
 stockwork, Mulberry mine, near 
 
 Bodmin, 19 
 Toadstone, influence on lead veins 
 
 in Derbyshire, 13 
 Tonite, 215 
 
 fumes from explosion of, 481 
 Tools used for working timber, 231 
 Toothed rolls, 556 
 Torches, 515 
 Torpedo, 304 
 
 Transmission of power, 163 
 Transport above ground, 373 
 
 underground, 348 
 Trays, 349 
 
 Treadwell Mine, Alaska, 47 
 Treatment of ores. See DRESSING, 
 
 Trelease's valve, 453 
 Trenching, sampling by, 632 
 Tribute, 641 
 
 advantages of working on, 643, 
 646 
 
 disadvantages of working on, 
 644, 645 
 
 system in Colorado, 647 
 
 at Festiniog, 649, 651 
 Triger's method of sinking, 277 
 Trimming stone by hand, 546 
 Trinidad, Pitch Lake of, 22 
 
 dressing of, 619 
 
 purification of, 598 
 Tripoli, occurrence of beds of, in 
 
 Sicily, 82 
 
 Trommels, 566, 567 
 Trouve", apparatus for examining 
 
 bore-holes, 150 
 Trubi, 82 
 Truck Acts, 668 
 Tubbing for shafts, cast-iron, 268 
 
 wood, 266 
 
 Tunnelling machines, 206 
 Turbine, used for hoisting, 389 
 Turgu-Ocna mine, 312 
 Turn plates, 354 
 Tuscany, occurrence of boric acid, 25 
 
 preparation of boric acid, 620 
 Tutwork, 638, 639 
 
 U 
 
 ULVEKSTON, haematite deposits of, 
 
 19 
 
 Umber, dressing of, 626 
 
 searching for by piercing, ic6 
 Undercurrents, 299 
 Undercutting machines, 199, 202 
 Underground pumping engines, 466 
 
 workings, 308 
 Underhand sloping, 327 
 Underlie or underlay, definition of, 9 
 United Kingdom, death-rate from 
 
 accidents, 700 
 
 United States, candle-holder used 
 in, 514 
 
 gathering of natural ice, 51 
 
 lamp used in, 516 
 
 legal definition of lode in, 9 
 
 occurrence of copper in, 34 
 
 gold ore, 45 
 
 iron ore, 54 
 
 lead ore, 55 
 
 natural gas, 59 
 
 petroleum, 67 
 
 phosphate of lime, 68 
 
 quicksilver ore, 71 
 
 silver ore, 76 
 
 trees used for mining purposes, 
 
 228 
 
 Universal pick, 153 
 Unstratified deposits, 4 
 Upcast shaft, 484 
 Uppers, dust from boring, 685 
 Upthrow, 91 
 
 Upward-current separators, 574 
 Utah, silver-bearing sandstone, 79 
 
 VAL-DE-TRAVEES, Switzerland, bi- 
 tuminous limestone of, 22 
 Value of product, payment by, 641 
 Valve, butterfly, 453 
 
 double-beat, 454 
 
 Jan Ham's, 453 
 
 Hake's mouth, 453 
 
 ordinary leather, 448 
 
 Teague's noiseless, 454 
 
 Trelease's, 453 
 Van den Broeck and Rutot, portable 
 
 boring outfit, 1 1 7 
 Van lode, length of, 1 1 
 Van mine, fire-damp at, 476 
 
 method of working the wide 
 
 lode, 331 
 
 Vanner, Frue, 585 
 V-bob, 446 
 Vegetation on outcrop of lodes, 107 
 
INDEX. 
 
 743 
 
 Veins, definition of term, 5 
 
 heave sideways caused by slip 
 
 along line of dip, 91 
 influence of change of strike on, 
 
 '3 
 
 of enclosing rock on, 12, 13 
 intersections of, 12 
 mechanical filling of, 14 
 modes of working, 325-340 
 name applied to slate beds in 
 
 North Wales, 81 
 origin of, 14 
 varying width of, 16 
 Zimmermann's rule for finding 
 
 faulted portion of, 91 
 Veinstone, definition of, n 
 Velocity of air-current, measure- 
 ment of, 506, 507 
 Venezuela, discovery of gold in by 
 
 Plassard, 94 
 
 occurrence of gold in, 44 
 Ventilating appliances, elliciency 
 
 of, 509 
 Ventilation, 475 
 
 compressed air, 492 
 fans, 494 
 furnace, 490 
 steam jet, 492 
 water blast, 492 
 
 falling down shaft, 486 
 effect of, on timber, 230 
 measurement of amount of air 
 
 passing, 506 
 natural, 482 
 
 Victoria, gold-fields of, 46 
 Villiers' stopping gear, 425 
 Viola calaminaria, 104 
 Voicanicemanations,sulphurfrom,8i 
 
 rocks, 3 
 
 Vom Rath on the outcrop of the 
 
 silver veins of Butte, Montana, 98 
 
 Von Cotta, definition of a mineral 
 
 vein, 6 
 
 on the Zwitter of Altenberg, 84 
 Von Groddeck, definition of a 
 
 mineral vein, 6 
 Von Sandberger, definition of a 
 
 mineral vein, 6 
 
 on the lateral secretion theory, 1 5 
 Vugs, definition of, 6 
 Vulcano, sulphur from, 82 
 
 W 
 
 WADDLE fan, 497 
 
 Waggons for underground use, 350, 
 
 355-3 60 
 
 points to be considered in de- 
 signing, 361 
 
 Wales, barracks for workmen, 676 
 
 manganese ore in, 58 
 
 lead ore in, 331 
 
 slate in, 79 
 
 underground workings for slate, 
 
 312 
 Walker's circular saw, 203, 204 
 
 detaching hook, 423 
 
 shutter for Guibal fan, 496 
 Wallace on emanations of carbonic 
 
 acid at Alston Moor, 475 
 Wallaroo lode, discovery of, 93 
 Walling, 249 
 
 Walling stage, Galloway's, 409 
 Wall-plate, 236 
 Wall-posts, 240 
 Walls, Cleveland, 315 
 
 Festiniog, 312 
 
 of a lode, definition of, 10 
 Walton Brown on the resistance to 
 
 air-currents, 511 
 
 Wardwell stone-channelling ma- 
 chine, 202 
 
 Warming pan for dynamite, 213 
 Warocquere, 706 
 Washer, Australian, 539 
 
 De Beers, 540 
 
 revolving drum, 541 
 Washing ores, &c., 538 
 Wash-out fault, 87 
 Washing-pit used in North Wales, 
 
 539 
 
 Water, amount used by siphon 
 
 separator, 579 
 
 amount used in stamping, 551 
 barrel for winding, 437 
 column compressors, 165 
 excavating by, 226, 292 
 from dressing works, purifica- 
 tion of, 667 
 gauge, 508 
 
 irruptions of, into mines, 707 
 jet ventilating apparatus, 492 
 motion of particles in, 568 
 power used for working pumps, 
 
 442 
 
 spray for laying dust, 685 
 tanks, automatic, 438 
 used for rending rocks, 208 
 wheel used for hoisting, 389 
 
 Watertight linings for shafts, 266 
 
 Weathering of diamond-bearing 
 
 rock, 6 10 
 fire-clay, 611 
 ironstone, 6u 
 phosphate of lime, 611 
 
 Wedge, 154, 208 
 
 Elliott multiple, 208 
 
 Wedging-crib, 267, 270 
 
 Weight, payment by, 639 
 
744 
 
 INDEX. 
 
 Wells, 304 
 
 boring by rotation, 117 
 
 driven, 137 
 We Us light, 516 
 Welsh barracks, 676 
 
 manganese ore, occurrence of, 
 
 58 
 
 dressing of, 625 
 lead ore, 331 
 miner's clogs, 672 
 slate mines, 79, 312 
 Wenstrom magnetic separator, 605 
 Werner, definition of a mineral 
 
 vein, 6 
 
 Wery's stopping gear, 425 
 West and Darlington, hydraulic 
 
 counterpoise, 458 
 hydraulic plungers for working 
 
 inclined rods, 447 
 Wheal Mary Ann, section of lode 
 
 at, 6 
 
 Wheelbarrow, 350 
 Wheels for mire-waggons, 357 
 Whipsiderry, 388 
 White's sleeper, 353 
 Whitney, on the "Great Quartz 
 
 Vein " of California, 45 
 Wicks, candle, 513 
 Wide veins, method of working, 
 
 33i 
 Wieliczka salt mines, 315 
 
 timber chocks, 245 
 Wind-bore, 448 
 Winding, 387 
 
 drum, 391 
 
 engines, 390 
 
 men at Carn Brea mine, 533 
 
 pulleys, 397 
 
 removing water by, 437 
 Windlass, 388 
 Windmills used for working pumps, 
 
 442 
 
 Winstanley's machine, 204 
 Winze, 326 
 Winzes, use of for ventilating, 489, 
 
 490 
 Wire saw, 204 
 
 Witwatersrand, 41 
 
 Wolf's magnetic lock for safety 
 
 lamps, 522 
 
 Woodbury ore concentrator, 586 
 Wooden pipes, 450 
 
 plugs used for rending rocks, 
 
 208 
 
 pulley frame, 395 
 Working barrel of pump, 448 
 
 in constrained position, effect 
 
 on men, 688 
 
 masses by horizontal slices, 
 ascending, 345 
 descending, 341 
 mineral deposits, methods of, 
 
 285 
 places, iron and steel supports, 
 
 265 
 
 supported by masonry, 254 
 timbering, 244 
 regulations for mines, 655 
 Workings, carbonic acid in old, 501 
 
 laying out open, 288 
 Workmen, housing, 673 
 Wotherton mine, Shropshire, 13 
 Wrist, 310 
 Wrysgan mine, 314 
 
 YELLOW Jacket mine, heat at, 670 
 
 i 
 
 ZIMMERMAN'S rule for finding lost 
 
 part of a vein, 91 
 Zinc blende, minerals associated 
 
 with, 97 
 Diepenlinchen, method of 
 
 working, 346 
 
 ores, calcination of, 612, 615 
 dressing of, 625, 630 
 occurrence of, 85, 86 
 Z witter, or tin-bearing rock at Alten- 
 berg, 84 
 
 Printed by BALLANTYNK, HANSON & Co. 
 Edinburgh &= London 
 
A CATALOGUE 
 
 OF 
 
 SCIENTIFIC AND TECHNICAL WORKS 
 
 PUBLISHED BY 
 
 CHARLES GRIFFIN & COMPANY, 
 
 IM I T E O. 
 
 MESSRS. CHARLES GRIFFIN <k COMPANY'S 
 PUBLICATIONS may be obtained through any Bookseller 
 in the United Kingdom, or will be sent post free on receipt of 
 remittance to cover published price. To prevent delay, Orders 
 should be accompanied by a Remittance. Cheques and Postal 
 Orders to be crossed "SMITH, PAYNE & SMITHS." 
 
 GENERAL and MEDICAL CATALOGUES forwarded 
 Post-free on Application. 
 
 LON DON : 
 EXETER STREET, STRAND. 
 
INDEX TO AUTHORS. 
 
 PAGE 
 
 ALLINGHAM (W.), Navigation, . 5, 21 
 
 Meteorology, 21 
 
 ANGLIN (S.), Design of Structures, . 4 
 BARKER (D. WILSON-), Navigation 
 and Seamanship, . . . . 5, 21 
 
 BERING-ER (J. J. & C.), Assaying, . 8 
 BLACKMORE (E.), British Mercantile 
 Marine. .... 6, 21 
 
 BLOUN'f (B.) and BLOXAM (A. G.), 
 Chemistry for Engineers and Manu- 
 facturers, ...... 7 
 
 BLYTH (A. Wynter), Foods and Poisons, 9 
 BORCHER8 (Dr.), Electric Smelting, 29 
 BROTHERS (A.), Photography, . . 8 
 BRO UGH (B. H.), Mine-Surveying, . 10 
 BROWNE (W. R.), Fuel and Water, . 44 
 
 Mechanics, 10 
 
 BUCK (R. C.), Algebra and Trigono- 
 metry, 6, 21 
 
 BUTTERFIELD (W, J. A.), Gas 
 
 Manufacture, 11 
 
 COLE (Prof.), Practical Geology, . . 12 
 
 Open Air Studies in Geology, . . 12 
 
 CRIMP (W. S.), Sewage Disposal Works, 13 
 DAVIES (Surgeon-Major), Hygiene, . 14 
 DA VIS (Prof.), Biology,. . . .15 
 
 The Flowering Plant, ... 15 
 
 Zoological Pocket-Book, ... 15 
 
 DONKIN( Bryan), Gas and Oil Engines, 16 
 
 Efficiency of Steam Boilers, . . 16 
 
 DUERR (Geo.), Bleaching and Calico- 
 
 Printing, 14 
 
 DUPRE& HAKE (Manual of Chemistry),16 
 ETHERIDGE (R.), Stratigraphical 
 
 Geology, 32 
 
 E W ART ( Prof.), Preservation of Fish, . 16 
 FIDLER (Prof.), Bridge- Construction, 17 
 FOSTER (Prof. C. le Neve), Ore and 
 
 Stone Mining, 18 
 
 GRIFFIN (J. J.), Chemical Recreations, 19 
 GRIFFIN'S Electrical Price- Book, . 19 
 GRIFFIN'S ENGINEERING PUB- 
 LICATIONS 20 
 
 GRIFFIN'S GEOLOGICAL and 
 
 METALLURGICAL SERIES, . 22 
 GRIFFIN'S NAUTICAL SERIES, . 21 
 GRIFFIN'S SANITARY PUBLICA- 
 TIONS, . ... 22 
 GRIFFIN'S TECHNOLOGICAL 
 
 PUBLICATIONS, . .23 
 
 GU RL) EN (R.), Traverse Tables, . 19 
 
 GUTTMANN (O.), Blasting, . 19 
 
 HARBORD (F. W.), Steel, . 41, 50 
 
 HUGHES-GIBB (E.), How Plants Live, 17 
 HUGHES (H. W.), Coal Mining, . 24 
 HURST (Chas.), Valves, . .23 
 
 HURST (G. H.), Painters' Colours, . 25 
 
 Garment Dyeing and Cleaning . 25 
 
 Colour Theory (Practical Applica- 
 tions of), ... .25 
 JAMIESON (Prof.), MANUALS, Ad- 
 vanced and Elementary, . . .26 
 
 Steam Engine, 26 
 
 Applied Mechanics, . . . .26 
 
 Magnetism and Electricity, . . 26 
 
 JENKINS (H. C.), Metallurgical 
 
 Machinery, ... . . 41 
 
 JOHNSON (J. C. F.), Getting Gold, . 28 
 
 KNECHT&RAWSON, Dyeing, . . 27 
 
 LAFAR (Dr. F.), Micro-Organisms 
 
 (Utilization of), 47 
 
 PAGB 
 
 LAWN (J. G.), Mine Accounts, . . 28 
 MACKENZIE (T. ), Applied Mechanics,21,30 
 M< MIL LAN (W. G.), Electro - Metal- 
 lurgy, 29 
 
 & BORCHERS, Electric Smelting, 29 
 
 MILLAR (W. J.), Latitude and Longi- 
 tude, 21,30 
 
 MUNRO & JAMIESON'S Electrical 
 
 Pocket-Book, . . . 31 
 
 MUNRO (Dr.), Agricultural Chemistry, 31 
 MUNRO (R. D.), Steam- Boilers, . . 30 
 
 Kitchen Boiler Explosions, . . 30 
 
 N YSTROM'S Pocket-Book for Engineers, 31 
 PEARCE (W. J.), Painting and Decor- 
 ating, 33 
 
 PHILLIPS & B AUERMAN, Metallurgy, 34 
 POYNTING (Prof.), Mean Density of 
 
 the Earth, 34 
 
 PRAEGER (R. L.), Open Air Botany, . 33 
 R AN KIN E'S Applied Mechanics, . 35 
 
 Civil Engineering, 
 Machinery and Mill work. 
 
 - Steam Engine & other Prime Movers, 35 
 
 - Useful Rules and Tables. ... 35 
 
 - A Mechanical Text-Book. . . 35 
 
 - Miscellaneous Scientific Papers. . 36 
 REDGRAVE (G.R.), Cements, . . 36 
 REDWOOD (Boverton), Petroleum,. . 37 
 REED (Sir E. J.), Stability of Ships, . 38 
 REID (Geo., M.DA Practical Sanitation, 39 
 RICHMOND (H. D.), Dairy Chemistry, 38 
 RID DELL (Dr. Scott), Ambulance, . 40 
 RIDEAL (S., D.Sc.), Disinfection, . 39 
 ROBERTS -AUSTEN (Prof.), Metal- 
 
 lurgy and Alloys, ..... 41 
 draulics, 
 
 f.), Hydra 
 ld, Metallurgy of, 
 
 Seymour), 
 
 ROBINSON (Prof.) 
 ROSE (T. K.), Go 
 ROTHWELL, (C. F. 
 
 Textile Printing, 
 
 SALTER(Chas.), Micro-Organisms, . 
 S EATON (A. E.), Marine Engineering, 
 SEATON & ROUNTHWAITE, Marine 
 
 Engineers' Pocket-Book, . . . 
 SEELEY (Prof.), Physical Geology, . 
 SEXTON (Prof.), Elementary Metal- 
 
 lurgy, ....... 
 
 - Quantitative & Qualitative Analysis, 
 SH ELTON (W. V.), Mechanic's Guide 
 
 42 
 43 
 
 44 
 47 
 45 
 
 45 
 32 
 
 46 
 46 
 
 . ., , 44 
 
 SMITH, (Johnson), Shipmaster's Medical 
 Help, ...... 21,40 
 
 R. H.), Measurement 
 
 48 
 
 ielp, 
 
 SMITH (Prof. 
 Conversions, 
 
 Calculus for Engineers, . . .48 
 
 SYKES (Dr. W. J.). Brewing, . . 47 
 THOMSON & POYNTING (Profs.) 
 
 Text-Book of Physics, .... 49 
 TRAILL (T. W.), Boilers, Land and 
 
 Marine 49 
 
 TURNER (Thos.), Iron, Metallurgy of, 50 
 WALTON (T.), Know Your Own Ship, 
 
 21,51 
 WATKINSON (Prof. W. H.), Gas and 
 
 Oil Engines, 51 
 
 WELLS (S. H.), Engineering Drawing, 53 
 WIGLEY (T. B.), Goldsmith and 
 
 Jeweller's Art, 53 
 
 WRIGHT (Dr. Alder), The Threshold 
 
 of Science, 52 
 
 Oils and Fats, Soaps and Candles, . 52 
 
 YEAMAN (C. H.), Elec. Measurements, 53 
 YEAR-BOOK of Scientific Societies, . 64 
 
INDEX TO SUBJECT 
 
 PAGE 
 
 AGRICULTURAL CHEMISTRY, . 31 
 
 AIR ENGINES, 16 
 
 ALGEBRA 6 
 
 ALLOYS, 41 
 
 AMBULANCE, 40 
 
 ASSAYING 8 
 
 BACTERIOLOGY (Practical), . . 47 
 
 BIOLOGY, 15 
 
 BLASTING, 19 
 
 BLEACHING, 14 
 
 BOTANY, . . . .15, 17, 33, 47 
 BRIDGE-CONSTRUCTION, . . 17 
 BOILERS, Construction, ... 49 
 
 Efficiency of, . . . .16 
 
 Kitchen, Explosions of, . . 30 
 
 Management, . . . .30 
 
 BREWING, 47 
 
 CALCULUS FOR ENGINEERS, . 48 
 CALICO-PRINTING, . .14, 44 
 
 CEMENTS, 36 
 
 CHEMICAL ANALYSIS, Qualitative 
 
 and Quantitative, . . . .46 
 CHEMICAL RECREATIONS, . 19, 52 
 CHEMISTRY FOR ENGINEERS, . 7 
 
 for Manufacturers, ... 7 
 
 Inorganic, . . . . .16 
 
 COAL-MINING, 24 
 
 COLOURS, 25 
 
 COPPKR, Metallurgy of, ... 41 
 DAIRY CHEMISTRY, ... 38 
 DENSITY OF THE EARTH, . . 34 
 DESIGN (Engineering), ... 53 
 
 of Structures, .... 4 
 
 DISINFECTION and DISINFECT ANTS, 39 
 DRAWING (Engineering), ... 53 
 
 DYEING, 25, 27 
 
 ELECTRIC SMELTING, ... 29 
 ELECTRICAL MEASUREMENTS, . 53 
 Pocket-Book, .... 31 
 
 Price- Book 19 
 
 ELECTRICITY and MAGNETISM, . 26 
 ELECTRO-METALLURGY, . . 29 
 ENGINEERS, Pocket-books for, . 31, 45 
 
 Useful Rules for, ... 20, 35 
 
 ENGINEERING, Civil, ... 35 
 
 Marine, ..... 45 
 
 Drawing and Design, . .53 
 
 FERMENTATION, ... 47 
 
 FISH, Preservation of, ... 16 
 
 FOODS, Analysis of, ... 9 
 
 FUEL and WATER, . . . 44 
 
 GAS ENGINES,. . . 16,51 
 
 GAS MANUFACTURE, ... 11 
 GEOLOGY, Introduction to, . . 12 
 
 Physical, 32 
 
 Practical, 12 
 
 Stratigraphical, . . . .32 
 
 GOLD, Getting, 28 
 
 Metallurgy of. . . . .43 
 
 GOLDSMITH'S ART, ... 53 
 
 HYDRAULICS 42 
 
 HYGIENE, ... 13, 14, 39 
 
 PAOB 
 
 IRON, Metallurgy of, . . . .50 
 JEWELLER'S ART, . . . .53 
 KITCHEN BOILER EXPLOSIONS, . 30 
 LATITUDE and LONGITUDE, 
 
 To Find, ... 21, 30 
 
 MACHINE DESIGN, . . .53 
 
 MACHINERY and MILLWORK, 33, 41 
 MAGNETISM, ... .26 
 
 MARINE BOILERS, . . .49 
 
 Engineering, . . 45 
 
 MECHANICS, Applied 
 
 Elementary, . . . 21, 26, 30 
 
 Student's, 10 
 
 Advanced, . . . 26, 35 
 
 MEASUREMENTS, Conversion of, 48 
 
 Electrical, ... 53 
 
 MEDICINE and SURGERY, Domestic, 55 
 
 for Shipmasters, ... 40 
 
 MERCANTILE MARINE, British, 6 
 
 METALLURGY, Elementary, . 46 
 
 Introduction to, . . . 41 
 
 General, .... 34 
 
 of Gold, 48 
 
 of Iron, ..... 50 
 
 MICRO-ORGANISMS, Utilization of, 
 
 in the Arts and Manufactures, . 47 
 MINING- 
 
 Accounts and Book-keeping, . 28 
 
 Blasting, ... .19 
 
 Coal, .... .24 
 
 Ore and Stone, . . .18 
 
 Surveying, ... .10 
 
 NAUTICAL SUBJECTS, . . 21 
 
 NAVIGATION, ... .5 
 
 OILS and FATS, . . . .52 
 
 OIL ENGINES, ... .16 
 
 ORE MINING, . 18 
 
 PAINTING and DECORATING, . 33 
 
 PETROLEUM, 37 
 
 PHOTOGRAPHY, .... 8 
 PHYSICS, .... 26, 49, 52 
 POISONS, Detection of, . .9 
 
 SANITATION, ... 13, 14, 39 
 SCIENCE, Popular Introduction to, . 52 
 
 SEAMANSHIP, 5 
 
 SEWAGE, Disposal of, ... 18 
 SHIPMASTER'S MEDICAL GUIDE, 40 
 SHIPS, Loading, &c., of, . . 51 
 
 Stability of, . . . . 38, 51 
 
 SOAPS, Manufacture of, . . . 52 
 SOCIETIES, Year-book of, . . . 54 
 STEAM ENGINE, Elementary, . . 26 
 
 Advanced 26, 45 
 
 STEEL, Metallurgy of, . . 41, 50 
 STRUCTURES, Design of, . . .4 
 SURVEYING, Mine, . , 10 
 
 TEXTILE PRINTING, 14, 44 
 
 TRAVERSE TABLES, ... 19 
 TRIGONOMETRY, . . 6 
 
 VALVES and VALVE-GEARING, . 23 
 VARNISHES, Manufacture of, . . 25 
 ZOOLOGY, . . . ,15 
 
CHARLES GRIFFIN 4 CO. 1 8 PUBLICATIONS. 
 
 THE DESIGN OF STRUCTURES: 
 
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 PART III. NON-METALS : Oxygen and Oxides ; The Halogens Sulphur and Sul- 
 phates Anemic, Phosphorus, Nitrogen Silicon, Carbon, Boron Useful Tables. 
 
 "A XJHALLY MERITORIOUS WORK, that may be safely depended upon either for systematic 
 instruction or for reference." Nature. 
 
 " This work is one of the BEST of its kind. . . . Essentially of a practical character. 
 . . . Contains all the information that the Assayer will find necessary in the examination 
 f minerals." Engineer. 
 
 New Edition in Preparation. 
 
 PHOTOGRAPHY: 
 
 ITS HISTORY, PROCESSES, APPARATUS, AND MATERIALS. 
 
 Comprising Working Details of all the More Important Methods. 
 
 BY A. BROTHERS, F.R.A.S. 
 
 WITH TWENTY-FOUR FULL PAGE PLATES BY MANY OF THE PRO- 
 CESSES DESCRIBED, AND ILLUSTRATIONS IN THE TEXT. 
 
 In 8vo, Handsome Cloth. 
 
 GENERAL CONTENTS. PART. I. INTRODUCTORY Historical 
 Sketch ; Chemistry and Optics of Photography ; Artificial Light. 
 PART II. Photographic Processes. PART III. Apparatus. PART IV. 
 Materials. PART V. Applications of Photography ; Practical Hints. 
 
 " Mr. Brothers has had an experience in Photography so large and varied that any work 
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 entering with full details into the various processes, and VERY FULLY illustrated. The 
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 to obtain a copy as a reference work. " Photographic Work. 
 
 "The COMPLETEST HANDBOOK of the art which has yet been published. 
 
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SCIENTIFIC AND TECHNOLOGICAL WORKS. 9 
 
 WORKS BY A. WYNTER BLYTH, M.R.C.S., F.C.S., 
 
 Barrister-at-Law, Public Analyst for the County of Devon, and Medical Officer of Health for 
 
 St. Marylebone. 
 
 FOODS: 
 
 THEIR COMPOSITION AND ANALYSIS. 
 
 In Demy 8vo, with Elaborate Tables, Diagrams, and Plates. Handsome 
 Cloth. FOURTH EDITION. Price 21s. 
 
 GENERAL CONTENTS. 
 
 History of Adulteration Legislation, Past and Present Apparatus 
 useful to the Food- Analyst "Ash" Sugar Confectionery Honey 
 Treacle Jams and Preserved Fruits Starches Wheaten-Flour Bread 
 Oats Barley Rye Rice Maize Millet Potato Peas Chinese 
 Peas Lentils Beans MILK Cream Butter Oleo-Margarine 
 Butterine Cheese Lard Tea Coffee Cocoa and Chocolate Alcohol 
 Brandy Rum Whisky Gin Arrack Liqueurs Absinthe Principles 
 of Fermentation Yeast Beer Wine Vinegar Lemon and Lime 
 Juice Mustard Pepper Sweet and Bitter Almond Annatto Olive 
 Oil WATER Standard Solutions and Reagents. Appendix: Text of 
 English and American Adulteration Acts. 
 
 PRESS NOTICES OF THE FOURTH EDITION. 
 
 " Simply INDISPENSABLE in the Analyst's laboratory." The Lancet. 
 
 "THE STANDARD WORK on the subject. . . . Every chapter and every page gives 
 abundant i roof of the strict revision to which the work has been subjected. . . . The 
 section on MILK is, we believe, the most exhaustive study of the subject extant. . . . An 
 INDISPENSABLE MANUAL for Analysts and Medical Officers of Health." Public Health. 
 
 "A new edition of Mr. Wynter Blyth's Standard work, ENRICHED WITH ALL THB RECENT 
 DISCOVERIES AND IMPROVEMENTS, will be accepted as a boon." Chemical News. 
 
 POISONS: 
 
 THEIR EFFECTS AND DETECTION. 
 
 THIRD EDITION. In Large 8vo, Cloth, with Tables and Illustrations. 
 Price 21s. 
 
 GENERAL CONTENTS. 
 
 I . Historical Introdu ction. II . Classifi cation Statistics Connection 
 between Toxic Action and Chemical Composition Life Tests General 
 Method of Procedure The Spectroscope Examination of Blood and Blood 
 Stains. III. Poisonous Gases. IV. Acids and Alkalies. V. More 
 or less Volatile Poisonous Substances. VI. Alkaloids and Poisonous 
 Vegetable Principles. VII. Poisons derived from Living or Dead Animal 
 Substances. VIII. The Oxalic Acid Group. IX. Inorganic Poisons. 
 Appendix : Treatment, by Antidotes or otherwise, of Cases of Poisoning. 
 
 " Undoubtedly THB MOST COMPLETE WORK on Toxicology in our language." The Analyst (on 
 the Third Edition). 
 
 " As a PRACTICAL GUIDE, we know NO BETTER work. The Lancet (on the Third Edition). 
 ** In the THIRD EDITION, Enlarged and partly Re-written, NEW ANALYTICAL METHODS have 
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 Food-poisoning and in the Manifestations of Disease, have received special attention. 
 
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io CHARLES GRIFFIN * CO.'S PUBLICATIONS. 
 
 MINE-SURVEYING (A Text-Book of): 
 
 For the use of Managers of Mines and Collieries, Students 
 at the Royal School of Mines, &c. 
 
 BY BENNETT H. BROUGH, F.G.S., 
 
 Late Instructor of Mine-Surveying, Royal School of Mines. 
 With Diagrams. SIXTH EDITION, Enlarged and Revised. Cloth, 7s. 6d. 
 
 GENERAL CONTENTS. 
 
 General Explanations Measurement of Distances Miner's Dial Variation of 
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 Surveying with the Fixed Needle German Dial Theodolite Traversing Under- 
 ground Surface-Surveys with Theodolite Plotting the Survey Calculation of 
 Areas Levelling Connection of Underground- and Surface-Surveys Measuring 
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 Applications of Magnefic-Needle in Mining Appendices. 
 
 " Has PROVED itself a VALUABLE Text-book ; the BEST, if not the only one, in the English 
 language on the subject." Mining Journal. 
 
 "No English-speaking- Mine Agent w Mining Student will consider his technical library 
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 "A valuable accessory to Surveyors in every department of commercial enterprise,. 
 Fnlly deserves to hold its position as a STANDARD." CUury Guardian. 
 
 WO E K S 
 
 BY WALTER R. BROWNE, M.A., M. INST. C.E., 
 
 Late Fellow of Trinity College, Cambridge. 
 
 THE STUDENT'S MECHANICS: 
 
 An Introduction to the Study of Force and Motion. 
 
 With Diagrams. Crown 8vo. Cloth, 43. 6d. 
 
 " Clear in style and practical in method, 'THE STUDENT'S MECHANICS' is cordially to be 
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 FOUNDATIONS OF MECHANICS. 
 
 Papers reprinted from the Engineer. In Crown 8vo, is. 
 
 FUEL AND WATER: 
 
 A Manual for Users of Steam and Water. 
 BY PKOF. SCHWACKHflFKR AND W. R. BROWNE, M.A. (Seep. 44.) 
 
 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 11 
 
 GAS MANUFACTURE 
 
 (THE CHEMISTRY OF). 
 
 A Hand-Booh on the Production, Purification, and Testing 
 of Illuminating Gas, and the Assay of the Bye- 
 Products of Gas Manufacture. For the 
 Use of Students. 
 
 BY 
 
 W. J. ATKINSON BUTTERFIELD, M.A., F.C.S., 
 
 Head Chemist, Gas Works. Beckton, London, E. 
 With Numerous Illustrations. Handsome Cloth. Price 9s. 
 
 ' The BEST WORK of its kind which we have ever had the pleasure of re- 
 viewing." Journal of Gas Lighting. 
 
 GENERAL CONTENTS. 
 
 I. Raw Materials for Gas 
 
 Manufacture. 
 II. Coal Gas. 
 
 III. Carburetted Water Gas. 
 
 IV. Oil Gas. IX. Applications of Gas. 
 V. Enriching by Light Oils. X. Bye-Products. 
 
 VI. Final Details of Manu- 
 facture. 
 
 VII. Gas Analysis. 
 VIII. Photometry. 
 
 %* This work deals primarily with the ordinary processes of GAS MANUFACTURE 
 employed in this country, and aims especially at indicating the principles on which 
 they are based. The more modern, but as yet subsidiary, processes are fully treated 
 also. The Chapters on Gas Analysis and Photometry will enable the consumer to 
 
 grasp the methods by which the quality of the gas he uses is ascertained, and in the 
 hapter on The Applications of Gas, not only is it discussed as an illuminant, but 
 also as a ready source of heat and power. In the final Chapter, an attempt has been 
 made to trace in a readily-intelligible manner the extraction of the principal derivatives 
 from the crude BYE-PRODUCTS. The work deals incidentally with the most modern 
 developments of the industry, including inter alia the commercial production and 
 uses of acetylene and the application of compressed gas for Street Traction. The needs 
 of the Students in Technical Colleges and Classes have throughout been kept in view. 
 
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1 2 CHA RLE8 GRIFFIN <k CO. 'S P UBLICA TIONS. 
 
 Works by GRENVILLE A. J. COLE, M.R.I.A., F.G.S., 
 
 Professor of Geology in the Royal College of Science for Ireland. 
 
 PRACTICAL GEOLOGY 
 
 (AIDS IN): 
 
 WITH A SECTION ON PALEONTOLOGY. 
 SECOND EDITION, Revised. With Illustrations. Cloth, IDS. 6d. 
 
 GENERAL CONTENTS. PART I. SAMPLING OF THE EARTH'S 
 CRUST. PART II. EXAMINATION OF MINERALS. PART III. EXAMINA- 
 TION OF ROCKS. PART IV. EXAMINATION OF FOSSILS, 
 
 " Prof. Cole treats of the examination of minerals and rocks in a way that has nerer 
 been attempted before . . . DESKKVING OF THB HIGHEST PRAISE. Here indeed are 
 ' Aids ' INNUMERABLE and INVALUABLE. All the directions are giren with the utmost clear- 
 ness and precision." Atheneeum. 
 
 "To the younger workers in Geology, Prof. Cole's book will be as INDISPENSABLE as a 
 dictionary to the learners of a language." Saturday Review. 
 
 "That the work deserves its title, that it is full of ' AIDS,' and in the highest degree 
 ' PRACTICAL,' will be the verdict of all who use it." Nature. 
 
 " This EXCELLENT MANUAL . . . Will be A VERY GREAT HELP. . . . The Section 
 
 on the Examination of Fossils is probably the BEST of its kind yet published. . _ . FULL 
 of well-digested information from the newest sources and from personal research." Annals 
 f Nat. History. 
 
 OPEN-AIR STUDIES; 
 
 An Introduction to Geology Out-of-doors. 
 
 With 12 Full-Page Illustrations from Photographs. Cloth. 8s. 6d. 
 
 GENERAL CONTENTS. The Materials of the Earth A Mountain Hollow 
 Down the Valley Along the Shore Across the Plains Dead Volcanoes 
 A Granite Highland The Annals of the Earth The Surrey Hills The 
 Folds of the Mountains. 
 
 "The FASCINATING ' OPEN-AIR STUDIES' of PROF. COLE give the subject a GLOW 09 
 ANIMATION . . . cannot fail to arouse keen interest in geology." Geological Magazine. 
 
 "EMINENTLY READABLE . . . every small detail in a scene touched with a sym- 
 pathetic kindly pen that reminds one of the lingering brush of a Constable." Nature. 
 
 "The work of Prof. Cole combines ELEGANCE of STYLE with SCIENTIFIC THOROUGHNESS." 
 Petermann's Mittheilungen. 
 
 " The book is worthy of its title; from cover to cover it is STRONG with bracing freshness 
 of the mountain and the field, while its ACCURACY and THOROUGHNESS show that it is the 
 work of an earnest and conscientious student. . . . Full of picturesque touches which 
 are most welcome "Natural Science. 
 
 " A CHARMING BOOK, beautifully illustrated." A thenseum. 
 
 %* For the Companion-Volume on " OPEN Am BOTANY " see p. 33. 
 
 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 
 
 SEWAGE DISPOSAL WORKS: 
 
 A Guide to the Construction of Works for the Prevention of the 
 Pollution by Sewage of Rivers and Estuaries. 
 
 BY 
 
 W. SANTO CRIMP, M.lNST.C.K, F.G.S., 
 
 Late Assistant-Engineer, London County Council 
 
 With Tables, Illustrations in the Text, and 37 Lithographic Plates. Medium 
 
 8vo. Handsome Cloth. 
 SECOND EDITION, REVISED AND ENLARGED. 305. 
 
 PART I. INTRODUCTORY. 
 
 Introduction. 
 
 Details of River Pollutions and Recommenda- 
 tions of Various Commissions. 
 
 Hourly and Daily Flow of Sewage. 
 
 The Pail System as Affecting Sewage. 
 
 The Separation of Rain-water from the Sewage 
 Proper. 
 
 Settling Tanks. 
 Chemical Processes. 
 The Disposal of Sewage-sludge. 
 The Preparation of Land for Sewage Dis- 
 posal. 
 Table of Sewage Farm Management. 
 
 PART II. SEWAGE DISPOSAL WORKS IN OPERATION THEIK 
 CONSTRUCTION, MAINTENANCE, AND COST. 
 
 Illustrated by Plates showing the General Plan and Arrangement adopted 
 in each District. 
 
 Map of the LONDON Sewage System. 
 
 Crossness Outfall. 
 
 Barking Outfall. 
 
 Doncaster Irrigation Farm. 
 
 Beddington Irrigation Farm, Borough of 
 Croydon. 
 
 Bedford Sewage Farm Irrigation. 
 
 Dewsbury and Hitchin Intermittent Fil- 
 tration. 
 
 Merton, Croydon Rural Sanitary Authority. 
 
 Swanwick, Derbyshire. 
 
 The Baling Sewage Works. 
 
 Chiswick. 
 
 Kingston-on-Thames, A. B. C. Process. 
 
 Salford Sewage Works. 
 
 Bradford, Precipitation. 
 
 New Maiden, Chemical Treatment and 
 
 Small Filters. 
 Friern Barnet. 
 
 Acton, Ferozone and Pol ante Process, 
 Ilford, Chadwell, and Dagenham Work*. 
 CoYentry. 
 Wimbledon. 
 Birmingham. 
 Margate. 
 Portsmouth. 
 
 BERLIN Sewage Farms. 
 Sewage Precipitation Works, Dortmund 
 
 (Germany). 
 Treatment of Sewage by Electrolysis. 
 
 %* From the fact of the Author's having, for some years, had charge of the Main 
 Drainage Works of the Northern Section of the Metropolis, the chapter on LONDON will be 
 found to contain many important details which would not otherwise have been available. 
 
 " All persons interested in Sanitary Science owe a debt of gratitude to Mr. Crimp. . . . 
 His work will be especially useful to SANITARY AUTHORITIES and their advisers . . . 
 EMINENTLY PRACTICAL AND USEFUL . . . gives plans and descriptions of MANY or TH 
 MOST IMPORTANT SEWAGE WORKS of England . . . with very valuable information as to 
 the COST of construction and working of each. . . . The carefully-prepared drawings per- 
 mit of an easy comparison between the different systems." Lmncet. 
 
 " Probably the MOST COMPLETE AND BEST TREATISE on the subject which has appeared 
 in our language . . Will prove of the greatest use to all who have the problem 01 
 
 Sewage Disposal to tooo.*Ji*i*rf& M*d*c*l J *m*l. 
 
 LONDON : EXETER STREET, STRAND. 
 
i 4 CHARLES GRIFFIN & CO.'S PUBLICATIONS. 
 
 Griffin's "Poeket-Book" Series. 
 
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 BY 
 
 SURGEON-MAJOR A. M. DAVIES, D.P.H.Oamb., 
 
 Late Assistant-Professor of Hygiene, Army Medical School. 
 
 General Contents. 
 
 Air and Ventilation Water and Water Supply Food and Dieting 
 Removal and Disposal of Sewage Habitations Personal Hygiene Soils 
 and Sites Climate and Meteorology Causation and Prevention of Disease 
 Disinfection. 
 
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 high place among the text-books of the day." Sanitary Record. 
 
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SCIENTIFIC AND TECHNOLOGICAL WORKS. 15 
 
 W O E K S 
 
 BY J. R. AINSWORTH DAVIS, B.A., 
 
 PROFESSOR OF BIOLOGY, UNIVERSITY COLLEGE, ABERYSTWYTH; 
 
 EXAMINER IN ZOOLOGY, UNIVERSITY OF ABERDEEN. 
 
 DAVIS (Prof. Ainsworth): BIOLOGY (An Ele- 
 
 mentary Text-Book of). In large Crown 8vo, Cloth. SECOND EDITION. 
 
 PART I. VEGETABLE MORPHOLOGY AND PHYSIOLOGY. With Complete Index- 
 Glossary and 128 Illustrations. Price 8s. 6d. 
 
 PART II. ANIMAL MORPHOLOGY AND PHYSIOLOGY. With Complete Index- 
 Glossary and 108 Illustrations. Price IDS. 6d. 
 
 EACH PART SOLD SEPARATELY. 
 
 V* NOTE The SECOND EDITION has been thoroughly Revised and Enlarged, 
 
 and includes all the leading selected TYPES in the various Organic Groups. 
 
 "Certainly THE BEST 'BIOLOGY' with which we are acquainted. It owes its pre- 
 eminence to the fact that it is an EXCELLENT attempt to present Biology to the Student as a 
 CORRELATED AND COMPLETE SCIENCE. The glossarial Index is a MOST USEFUL addition." 
 British Medical Journal. 
 
 " Furnishes a CLEAR and COMPREHENSIVE exposition of the subject in a SYSTEMATIC 
 form." Saturday Review. 
 
 " Literally PACKED with information." Glasgow Medical Journal 
 
 DAVIS (Prof. Ainsworth): THE FLOWERING 
 
 PLANT, as Illustrating the First Principles of Botany. Large Crown 
 8vo, with numerous Illustrations. 35. 6d. SECOND EDITION. 
 
 "It would be hard to find a Text-book which would better guide the student to an accurate 
 knowledge of modern discoveries in Botany. . . . The SCIENTIFIC ACCURACY of statement, 
 and the concise exposition of FIRST PRINCIPLES make it valuable for educational purposes. la 
 the chapter on the Physiology of Flowers, an admirable rtsume is given, drawn from Darwin, 
 Hermann Miiller, Kerner, and Lubbock, of what is known of the Fertilization of Flowers." 
 
 DAVIS and SELENKA: A ZOOLOGICAL 
 
 POCKET-BOOK; Or, Synopsis of Animal Classification. Comprising 
 Definitions of the Phyla, Classes, and Orders, with Explanatory Remarks 
 and Tables. By Dr. Emil Selenka, Professor in the University of 
 Erlangen. Authorised English translation from the Third German 
 Edition. In Small Post 8vo, Interleaved for the use of Students. Limp 
 Covers, 45. 
 
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 HENSIVK and SUCCESSFUL attempt to present us with a scheme of the natural arrangement of 
 ed.J 
 
 world." Edin. Med.Jo 
 " Will prove very serviceable to those who are attending Biology Lectures. . . . Tfce 
 traMlation is accurate and clear." Lancet. 
 
 LONDON: EXETER STREET. STRAND. 
 
1 6 CHARLES GRIFFIN <k CO.'S PUBLICATIONS. 
 
 GAS, OIL, AND AIR ENGINES: 
 
 A Practical Text - Book on Internal Combustion Motors 
 without Boiler. 
 
 BY BRYAN DONKIN, M.lNsx.C.E. 
 
 SECOND EDITION, Revised throughout and Enlarged. With numerous 
 additional Illustrations. Large 8vo. 255. 
 
 GBNBRAL CONTENTS. Gas Engines : General Description History and Develop- 
 ment British, French, and German Gas Engines Gas Production for Motive Power 
 Theory of the Gas Engine Chemical Composition of Gas in Gas Engines Utilisation of 
 Heat Explosion and Combustion. Oil MotOPS : History and Development Various 
 Types Priestman's and other Oil Engines. Hot-AiP Engines: History and Develop- 
 ment Various Types: Stirling's, Ericsson's, &c., &c. 
 
 "The BEST BOOK NOW PUBLISHED on Gas, Oil, and Air Engines. . . . Will be of 
 VERY GREAT INTEREST to the numerous practical engineers who have to make themselves 
 familiar with the motor of the day. . . . Mr Donkin has the advantage of LONG 
 
 PRACTICAL EXPERIENCE, Combined With HIGH SCIENTIFIC AND EXPERIMENTAL KNOWLEDGE, 
 
 and an accurate perception of the requirements of Engineers." The Engineer. 
 
 "We HEARTILY RECOMMEND Mr. Donloin's work. ... A monument of careful 
 labour. . . . Luminous and comprehensive." -J ournal of Gas Lighting . 
 
 BY THE SAME AUTHOR. {Shortly. 
 
 THE HEAT EFFICIENCY OF STEAM BOILERS 
 
 (LAND AND MARINE). 
 
 Many Experiments on Many Types, showing Results as to Evaporation, 
 Heating Value of Fuel, Analysis of Gases, &c., &c. By BRYAN DONKIN, 
 M. Inst.C.E. With Illustrations and Tables. In 410. 
 
 INORGANIC CHEMISTRY (A Short Manual of). 
 
 BY A. DUPRE, Ph.D., F. R. S., AND WILSON HAKE, 
 
 Ph.D., F.I.C., F.C.S., of the Westminster Hospital Medical School 
 SECOND EDITION, Revised. Crown 8vo. Cloth, ys. 6d. 
 " A well-written, clear and accurate Elementary Manual of Inorganic Chemistry. . . . 
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 MKKTAL WORK TREBLY INTERESTING BECAUSE INTELLIGIBLE." Saturday RfVtfW. 
 
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 the remainder comes afterwards to him in a manner much more simple and easily acquired. 
 The work is AN EXAMPLE OF THE ADVANTAGES OF THE SYSTEMATIC TREATMENT of a 
 Science over the fragmentary style so generally followed. BY A LONG WAY THE BEST of the 
 small Manuals for Students. Analyst. 
 
 EWART (J. Cossar, M.D., F.R.S.E., Regius 
 
 Professor of Natural History, University of Edinburgh). 
 
 HINTS ON THE PRESERVATION OF FISH, in Reference to 
 Food Supply. In Crown 8vo. Wrapper, 6d. 
 
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SCIENTIFIC AND TECHNOLOGICAL WORKS. 17 
 
 SECOND EDITION, Revised. Royal &vo. With numerous Illustrations and 
 13 Lithographic Plates. Handsome Cloth. Price y>s. 
 
 BRIDGE-CONSTRUCTION 
 
 (A PRACTICAL TREATISE ON): 
 
 Being a Text-Book on the Construction of Bridges in 
 Iron and Steel. 
 
 FOR THE USE OF STUDENTS, DRAUGHTSMEN, AND ENGINEERS. 
 BY T. CLAXTON FIDLER, M. INST. C.E., 
 
 Prof, of Engineering, Unirersity College, Dundee. 
 
 ' ' Mr. FIDLER'S SUCCESS arises from the combination of EXPERIENCE and 
 SIMPLICITY OF TREATMENT displayed on every page. . . . Theory is kept in 
 subordination to practice, and his book is, therefore, as useful to girder-makers 
 as to students of Bridge Construction." ("The Architect" on the Second 
 Edition.") 
 
 " Of late years the American treatises on Practical and Applied Mechanics 
 have taken the lead . . . since the opening up of a vast continent has 
 given the American engineer a number of nevf bridge -problems to solve 
 . . . but we look to the PRBSBNT TREATISE ON BRIDGE-CONSTRUCTION, arid 
 the Forth Bridge, to bring us to the front again." Engineer. 
 
 " One of the VERY BBST RICENT WORKS on the Strength of Materials and its 
 application to Bridge- Construction. . . Well repays a careful Studj ' 
 Engineering. 
 
 "An INDISPENSABLE HANDBOOK for the practical Engineer." Nature. 
 
 HOW PLANTS LIVE AND WORK : 
 
 A Simple Introduction to Real Life in the Plant-world, 
 Based on Lessons originally given to Country Children. 
 
 BY ELEANOR HUGHES-GIBB. 
 
 With Illustrations. Crown 8vo. Cloth. 2s. 6d. 
 
 %* The attention of all interested in the Scientific Training of the Young 
 is requested to this DELIGHTFULLY FRESH and CHARMING LITTLE BOOK. 
 It ought to be in the hands of every Mother and Teacher throughout the land. 
 
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 SCIENTIFICALLY ACCURATE, the first lessons in plant-life are set before it." 
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 the young." Scotsman. 
 
 LONDON: EXETER STREET, STRAND. 
 
1 8 CHARLES ORIFFIN d, CO:S PUBLICATIONS. 
 
 ORE & STONE MINING. 
 
 BY 
 
 C. LE NEVE FOSTER, D.Sc., F.R.S., 
 
 PROFESSOR OK MINING. ROYAL COLLEGE OF SCIENCE H.M. INSPECTOR OF MINES 
 
 SECOND EDITION. With Frontispiece and 716 Illustrations. 345. 
 
 " Dr. Foster's book was expected to be EPOCH-MAKING, and it fully justifies such expec- 
 tation. ... A MOST ADMIRABLE account of the mode of occurrence of practically ALL 
 KNOWN MINERALS. Probably stands UNRIVALLED for completeness." The Mining Journal. 
 
 GENERAL CONTENTS. 
 
 INTRODUCTION. Mode of Occurrence of Minerals : Classification : Tabular 
 Deposits, Masses Examples: Alum, Amber, Antimony, Arsenic, Asbestos, Asphalt, 
 Barytes, Borax, Boric Acid, Carbonic Acid, Clay, Cobalt Ore, Copper Ore, Diamonds, 
 Flint, Freestone, Gold Ore, Graphite, G-ypsum, Ice, Iron Ore, Lead Ore, Manganese 
 Ore, Mica, Natural Gas. Nitrate of Soda, Ozokerite, Petroleum, Phosphate of Lime, 
 Potassium Salts, Quicksilver Ore, Salt, Silver Ore, Slate, Sulphur, Tin Ore, Zinc Ore. 
 Faults. Prospecting: Chance Discoveries Adventitious Finds Geology as a 
 Guide to Minerals Associated Minerals Surface Indications. Boring: Uses of 
 Bore-holes Methods of Boring Holes: i. By Rotation, ii. By Percussion with Rods, 
 iii. By Percussion with Rope. Breaking Ground : Hand Tools Machinery- 
 Transmission of Power Excavating Machinery : i. Steam Diggers, ii. Dredges, 
 iii. Rock Drills, iv. Machines for Cutting Grooves, v. Machines for Tunnelling 
 Modes of using Holes Driving and Sinking Fire-setting Excavating by Water. 
 Supporting Excavations: Timbering Masonry Metallic Supports Watertight 
 Linings Special Processes. Exploitation : Open Works : Hydraulic Mining- 
 Excavation of Minerals under Water Extraction of Minerals by Wells and Bore- 
 holes Underground Workings Beds Veins Masses. Haulage or Transport: 
 Underground: by Shoots, Pipes, Persons, Sledges, Vehicles, Railways, Machinery, 
 Boats Conveyance above Ground. Hoisting or Winding: Motors, Drums, and 
 Pulley Frames Ropes, Chains, and Attachments Receptacles Other Appliances 
 Safety Appliances Testing Ropes Pneumatic Hoisting. Drainage : Surface Water 
 Dams Drainage Tunnels Siphons Winding Machinery Pumping Engines 
 above ground Pumping Engines below ground Co-operative Pumping. Ventila- 
 tion : Atmosphere of Mines Causes of Pollution of Air Natural V en ti'ation 
 Artificial Ventilation : i. Furnace Ventilation, ii. Mechanical Ventilation Testing 
 the Quality of Air Measuring the Quantity and Pressure of the Air Efficiency of 
 Ventilating Appliances Resistance caused by Friction. Lighting : Reflected 
 Daylight Candles Torches Lamps Wells Light Safety Lamps Gas Electric 
 Light. Descent and Ascent : Steps and Slides Ladders Buckets and Cages Man 
 
 Magnetic Attraction iii. Chemical Processes : Solution, Evaporation and Crystal- 
 lisation, Atmospheric Weathering, Calcination, Cementation, Amalgamation A p- 
 plication of Processes Loss in Dressing Sampling. Principles of Employment 
 of Mining Labour : Payment by Time, Measure, or Weight By Combination of 
 these By Value of Product. Legislation affecting Mines and Quarries: 
 Ownership Taxation Working Regulations Metalliferous Mines Regulation Acts 
 Coal Mines Regulation Act Other Statutes. Condition of the Miner : Clothing 
 Housing Education Sickness Thrift Recreation. Accidents: Death Rate of 
 Miners from Accidents Relative Accident Mortality Underground and Above- 
 ground Classification oi Accidents Ambulance Training. 
 
 "This EPOCH-MAKING work . . . appeals to MEN OF EXPERIENCE no less than to 
 students . . . gives numerous examples from the MINING PRACTICE of EVERY COUNTRY. 
 Many of its chapters are upon subjects not usually dealt with in text books. . . Of 
 great interest. . . . Admirably illustrated." Berg- und Hiittenmannische Zeitung. 
 
 "This SPLENDID WORK." Oesterr. Ztschrft. fur Berg- und Hiitten-wesen, 
 
 LONTX)N: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 19 
 
 SECOND EDITION, 8s. 6d. Leather, for the Pocket, 8s. 6d. 
 
 GRIFFIN'S ELECTRICAL PRICE-BOOK. 
 
 For Electrical, Civil, Marine, and Borough Engineers, Local 
 
 Authorities, Architects, Railway Contractors, &e., &e. 
 
 EDITED BY H. J. DOWSING, 
 
 Member of the Institution of Electrical Engineers; of the Society of Arts; of the London 
 
 Chamber of Commerce, &*c. 
 
 " The ELECTRICAL PRICE-BOOK REMOVES ALL MYSTERY about the cost of Electrical 
 Power. By its aid the EXPENSE that will be entailed by utilising electricity on a large or 
 small scale can be discovered." Architect. 
 
 " The value of this Electrical Price-Book CANNOT BE OVER-ESTIMATED. . . . Will 
 save time and trouble both to the engineer and the business man." Machinery. 
 
 GRIFFIN (John Joseph, F.C.S.) : 
 
 CHEMICAL RECREATIONS : A Popular Manual of Experimental 
 Chemistry. With 540 Engravings of Apparatus. Tenth Edition. Crown 
 8vo. Cloth. Complete in one volume, Parts I. and II. Cloth, gilt 
 top, 12/6. 
 
 Part II. The Chemistry of the Non-Metallic Elements, 10/6. 
 
 GURDEN (Richard Lloyd, Authorised Surveyor 
 
 for the Governments of New South Wales and Victoria) : 
 
 TRAVERSE TABLES : computed to Four Places Decimals for every 
 Minute of Angle up to 100 of Distance. For the use of Surveyors and 
 Engineers. FOUHR.TH EDITION. Folio, strongly half-bound, 2i/. 
 \* Published with Concurrence of the Surveyors- General for New South 
 Wales and Victoria. 
 
 " Those who have experience in exact SURVEY-WORK will best know how to appreciate 
 the enormous amount of labour represented by this valuable book. The computations 
 enable the user to ascertain the sines and cosines for a distance of twelve miles to within 
 half an inch, and this BY REFERENCE TO BUT ONE TABLE, in place of the usual Fifteen 
 minute computations required. This alone is evidence of the assistance which the Tables 
 ensure to every user, and as every Surveyor in active practice has felt the want of sucV 
 aaustance, few knowing of their publication will remain without them." Engineer. 
 
 In Large Svo, with Illustrations and Folding-Plates. IQS. 6d. 
 
 BLASTING: 
 
 A Handbook for the Use of Engineers and others Engaged in 
 Mining, Tunnelling, Quarrying, &.C. 
 
 BY OSCAR GUTTMANN, Assoc. M. INST. C.E. 
 
 Member of the Societies of Civil Engineers and A rchitects of Vienna and Budapest, 
 Corresponding Member of the Imp. Roy. Geological Institution of Austria, &c. 
 
 GENERAL CONTENTS. Historical Sketch Blasting Materials Blasting Pow- 
 der Various Powder-mixtures Gun-cotton Nitro-glycerine and Dynamite 
 Other Nitro-compounds Sprengel's Liquid (acid) Explosives Other Means of 
 Blasting Qualities, Dangers, and Handling of Explosives Choice of Blastiug 
 Materials Apparatus for Measuring Force Blasting in Fiery Mines Means cf 
 Igniting Charges Preparation of Blasts Bore-holes Machine-drilling Chamber 
 Mines Charging of Bore-holes Determination of the Charge Blasting in Bore- 
 holes Firing Straw and Fuze Firing Electrical Firing Substitutes for Electrical 
 Firing Results of Working Various Blasting Operations Quarrying Blasting 
 Masonry, Iron and Wooden Structures Blasting in earth, under water, of ice, &c. 
 
 'This ADMIRABLE work." Colliery Guardian. 
 
 "Should prove a vade-mecum to Mining Engineers and all engaged in practical work. 
 Iron and Coal Trades Review. 
 
 LONDON: EXETER STREET, STRAND. 
 
20 CHARLES GRIFFIN A CO.'S PUBLICATIONS. 
 
 Griffin's Standard Publications 
 
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 ENGINEERS, ELECTRICIANS, ARCHITECTS, BUILDERS, 
 NAVAL CONSTRUCTORS, AND SURVEYORS. 
 
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 The Steam-Engine, . . RANKINE, JAMIESON, . 35, 26 
 
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 Management, R. D. MUNRO, . 30 
 
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 " MR. WALTON'S book will be found VERY USEFUL." The Engineer. 
 
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 ' WELL WORTH the money . . . EXCEEDINGLY HELPFUL" Shipping World. 
 
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 A Medical and Surgical Help for Shipmasters and Officers 
 
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 " SOUND, JUDICIOUS, REALLY HELPFUL." 7 'he Lancet. 
 
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 LONDON: EXETER STREET, STRAND. 
 
22 
 
 CHARLES GRIFFIN <k CO. 'S PUBLICATIONS. 
 
 Griffin's Geological, Mining, and 
 Metallurgical Publications. 
 
 Geology (Stratigraphieal), 
 (Physical), . 
 (Practical), . 
 ,, (Introduction to), 
 
 Mine Accounts, . 
 
 Mine-Surveying, 
 
 Mining, Coal, . 
 
 ,, Ore and Stone, . 
 
 Blasting and Explosives, 
 
 Assaying, .... 
 
 Metallurgy, 
 
 ,, (Introduction to), 
 ,, (Elementary), 
 
 Gold, Metallurgy of, 
 
 Getting Gold, . 
 
 Iron, Metallurgy of, 
 
 Electro-Metallurgy, . 
 
 Electric Smelting, . 
 
 R. ETHERIDGE, . 
 PROF. SEELEY, . 
 PROF. COLE, 
 
 
 
 PROF. LAWN, 
 B. H. BROUGH, . 
 H. W. HUGHES,. 
 
 PROF. LE NEVE FOSTER, 
 
 O. GUTTMANN, . 
 
 J. J. & C. BERINGER, 
 
 PHILLIPS AND BAUERMAN, 
 
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 PROF. SEXTON, . 
 
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 THOS. TURNER, . 
 
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 tants, 
 
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 Foods and Poisons, . 
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 Sewage Disposal Works,. 
 
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 WM. JOHNSON SMITH, . 
 A. WYNTER BLYTH, . 
 SURGEON-MAJOR DAVIES, 
 DR. GEO. REID, . 
 SANTO CRIMP, 
 
 32 
 32 
 12 
 12 
 28 
 10 
 24 
 18 
 19 
 8 
 34 
 41 
 46 
 43 
 28 
 50 
 29 
 
 BORCHERS AND M'MlLLAN, 29 
 
 Griffin's "Health" Publications. 
 
 40 
 
 39 
 
 40 
 
 9 
 
 14 
 3fr 
 13 
 
 Hygienic Prevention Of /DR. SQUIRE. [See Medical 
 
 Consumption, 
 
 Catalogue.] 
 
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SCIENTIFIC AND TECHNOLOGICAL WORKS. 23 
 
 Griffin's Chemical and Technological Publications, 
 
 Chemistry for Engineers 
 
 and Manufacturers, . MM. BLOUNT AND BLOXAM, 7 
 Bleaching- and Calico- 
 Printing, . . . GEO. DUERR, . . 14 
 Brewing, .... DR. SYKES, . . 47 
 Cements, . . . . G. R. REDGRAVE, . 36 
 Disinfectants, . . . DR. RIDEAL, . . 39 
 Dyeing, .... MM. KNECHT AND RAWSON, 27 
 ,, and Cleaning, . G. H. HURST, . . 25 
 
 Fermentation, . . , LAFAR AND SALTER, . 47 
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 In Large 8vo. With Numerous Illustrations. Price 7s. 6d. 
 
 VALVES AND VALVE-GEARING: 
 
 A PRACTICAL TEXT-BOOK FOR THE USE 
 OF ENGINEERS, DRAUGHTSMEN, AND STUDENTS. 
 
 BY 
 
 CHARLES HURST, Practical Draughtsman. 
 
 " USEFUL and THOROUGHLY PRACTICAL. Will undoubtedly be found of GREAT VALUE to 
 all concerned with the design of Valve-gearing." Mechanical World. 
 
 " Dealt with in a SIMPLE and INTERESTING manner. . . . Almost EVERT TYPE of 
 VALVE and its gearing is cleatl set forth, and illustrated in such a way as to be READILY 
 TJNDKRSTOOD and PRACTICALLY APPLIED by either the Engineer, Draughtsman, or Student. 
 . . . Should prove both USEFUL and VALUABLE to all Engineers s eking for RELIABLE and 
 CLEAR information on the subject. Its moderate price brings ir within the reach of all." 
 Industries am Iron 
 
 " Mr. HURST'S work is ADMIRABLY suited to the needs of the practical mechanic. . . . 
 It is free from any elaborate theoretical discussions, and the explanations of the various 
 types of valve-gpar are accompanied by diagrams which render them EASILY UNDERSTOOD." 
 The Scientific American. 
 
 LONDON: EXETER STREET, STRAND. 
 
24 QHARLSS GRIFFIN A CO:S PUBLICATIONS. 
 
 COAL-MINING (A Text-Book of): 
 
 FOR THE USE OF COLLIERY MANAGERS AND OTHERS 
 ENGAGED IN COAL-MINING. 
 
 BY 
 
 HERBERT WILLIAM HUGHES, F.G.S., 
 
 Assoc. Royal School of Mines, Certificated Colliery Manager. 
 THIRD EDITION. In Demy Svo, Handsome Cloth. With very Numerous 
 
 Illustrations > mostly reduced from Working Drawings. iSs. 
 "The details of colliery work have been fully described, on the ground that 
 collieries are more often made REMUNERATIVE by PERFECTION IN SMALL MATTERS 
 than by bold strokes of engineering. ... It frequently happens, in particular 
 localities, that the adoption of a combination of small improvements, any of 
 which viewed separately may be of apparently little value, turns an unprofitable 
 concern into a paying one." Extract from Author's Preface. 
 
 GENERAL CONTENTS. 
 
 Geology : Rocks -Faults Order of Succession Carboniferous System in Britain. 
 Goal : Definition and Formation of Coal Classification and Commercial Value of Coals, 
 Search for Goal : Boring various appliances used Devices employed to meet Difficulties 
 of deep Boring Special methods of Boring Mather & Platt's, American, and Diamond 
 systems Accidents in Boring Cost of Boring Use of Boreholes. Breaking Ground; 
 Tools Transmission of Power: Compressed Air, Electricity Power Machine Drills Coal 
 Cutting by Machinery Cost of Coal Cutting Explosives Blasting in Dry and Dusty 
 Mines Blasting by Electricity Various methods to supersede Blasting. Sinking: 
 Position, Form, and Size of shaft Operation of getting down to " Ston^-head" Method of 
 proceeding afterward* Lining shafts Keeping out Water by Tubbing Cost of Tubbing 
 Sinking by Boring Kind - Chaudron, and Lipmann methods Sinking through Quicksands 
 Cost of Sinking. Preliminary Operations : Driving underground Roads Supporting 
 Roof: Timbering, Chocks or Cogs, Iron and Steel Supports and Masonry Arrangement of 
 Inset. Methods of Working : Shaft, Pillar, and Subsidence Bord and Pillar System- 
 Lancashire Method Longwall Method Double Stall Method Working Steep Seams 
 Working Thick Seams Working Seams lying near together Spontaneous Combustion. 
 Haulage: Rails Tubs Haulage by Horses Self-acting Inclines Direct-acting Haulage 
 Main and Tail Rope Endless Chain- Endless Rope Comparison. Winding: Pit 
 Frames Pulleys Cages Ropes Guides Engines Drums Brakes Counterbalancing 
 Expansion Condensation Compound Engines Prevention of Overwinding Catches at pit 
 top Changing Tubs Tub Controllers Signalling. Pumping: Bucket and Plunger 
 Pumps Supporting Pipes in Shaft Valves Suspended lifts for Sinking Cornish and 
 Bull Engines Davey Differential Engine Worthington Pump Calculations as to size of 
 Pumps Draining D'eep Workings Dams. Ventilation: Quantity of air required- 
 Gases met with in Mines Coal-dust Laws of Friction Production of Air-currents 
 Natural Ventilation Furnace Ventilation Mechanical Ventilators Efficiency of Fans 
 Comparison of Furnaces and Fans Distribution of the Air-current Measurement of Air- 
 currents. Lighting : Naked Lights Safety Lamps Modern Lamps Conclusions 
 Locking and Cleaning Lamps Electric Light Underground Delicate Indicators. Works 
 at Surface; Boilers Mechanical Stoking Coal Conveyors Workshops. Preparation 
 of Coal for Market: General Considerations Tipplers Screens Varying the Sizes made 
 by Screens Belts Revolving Tables Loading Shoots Typical Illustrations of the arrange- 
 ment of Various Screening Establishments Coal Washing Dry Coal Cleaning Briquettes. 
 
 "Quite THK BEST BOOK of its kind . . .as PRACTICAL in aim as a book can be ... 
 touches upon every point connected with the actual working of collieries. The illustrations 
 are KXCKLLKNT." Athenaum. 
 
 " A Text-book on Coal-Mining is a great desideratum, and Mr. HUGHES possesses 
 ADMIRABLE QUALIFICATIONS for supplying it. ... We cordially recommend the work." 
 Colliery Guardian. 
 
 " Mr. HUGHES has had opportunities for study and research which fall to the lot of 
 but few men. If we mistake not, his text-book will soon come to be regarded as the 
 STANDARD WORK of its kind. " Birmingha m Daily Gazette. 
 
 %* Note. The first large edition of this work was exhausted within a few months of 
 publication. 
 
 LONDON: EXETER STEERT, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 25 
 
 WORKS BY GEORGE H. HURST, F.C.S., 
 
 Member of the Society of Chemical Industry ; Lecturer on the Technology of Painten' 
 Colours, Oils, and Varnishes, the Municipal Technical School, Manchester. 
 
 NEW WORK BY MR. HURST. 
 
 COLOUR-THEORY AND ITS PRACTICAL 
 
 APPLICATION TO PAINTING, DYEING, and 
 THE TEXTILE INDUSTRIES. 
 
 In Large Crown 8vo. With Illustrations and Plates (some in Colours). 
 
 HURST'S PAINTERS' COLOURS, OILS, AND 
 
 VARNISHES (A Practical Manual). SECOND EDITION, Revised and 
 Enlarged. With Illustrations. 12s. 6d. 
 
 GENERAL CONTENTS. Introductory THE COMPOSITION, MANUFACTURE, 
 ASSAY, and ANALYSIS of PIGMENTS, White, Red, Yellow and Orange, Green, 
 Blue, Brown, and Black LAKES Colour and Paint Machinery Paint Vehicles 
 (Oils, Turpentine, &c., &c.) Driers VARNISHES. 
 
 "This useful book will prove MOST VALUABLE." Chemical News. 
 
 " A practical manual in every respect . . . EXCEEDINGLY INSTRUCTIVE. The 
 section on Varnishes the most reasonable we have met with." Chemist and Druggist. 
 
 " VERY VALUABLE information is given." Plumber and Decorator. 
 
 " A THOROUGHLY PRACTICAL book, . . . the ONLY English work that satisfactorily 
 treats of the manufacture of oils, colours, and pigments." Chemical Trades' Journal. 
 
 " Throughout the work are scattered hints which are INVALUABLE." Invention. 
 
 HURST'S GARMENT DYEING and CLEANING 
 
 (A Practical Book for Practical Men). With Numerous Illustrations. 
 43. 6d. 
 
 GENERAL CONTENTS. Technology of the Textile Fibres Garment Cleaning 
 Dyeing of Textile Fabrics Bleaching Finishing of Dyed and Cleaned Fabrics 
 Scouring and Dyeing of Skin Rugs and Mats Cleaning and Dyeing of Feathers 
 Glove Cleaning and Dyeing Straw Bleaching and Dyeing Glossary of Drugs 
 and Chemicals Useful Tables. 
 
 " An UP-TO-DATE hand book has long been wanted, and Mr. Hurst has done nothing 
 more complete than this. An important work, the more so that several of the branches of 
 the craft here treated upon are almost entirely without English Manuals for the guidance 
 of worker?. The price brings it within the reach of all." Dyer and Calico- Printer. 
 
 " Mr. Hurst's work: DECIDEDLY FILLS A WANT ( . . . ought to be in the hands of 
 EVERY GARMENT DYER and cleaner in the Kingdom" Textile Mercttry. 
 
 LONDON: EXETER STREET, STRAND. 
 
26 CHARLES GRIFFIN A CO.'S PUBLICATIONS. 
 
 WORKS BY 
 ANDREW JAMIESON, M.lNST.C.E., M.I.E.E., F.R.S.E., 
 
 Prvfetstr tf Electrical Engineering, The Glasgow and West 0f Scotland 
 Technical College. 
 
 PROFESSOR JAMIESON'S ADVANCED MANUALS. 
 
 In Large Crown %vo. Fully Illustrated. 
 
 1. STEAM AND STEAM-ENGINES (A Text-Book on), 
 
 For the Use of Students preparing for Competitive Examinations. 
 With over 200 Illustrations, Folding Plates, and Examination Papers. 
 TWELFTH EDITION. Revised and Enlarged, 8/6. 
 
 " Professor Jamieson fascinates the reader by his CLEARNESS OF CONCEPTION ANU 
 iiMPLiciTY OF EXPRESSION. His treatment recalls the lecturing of Faraday." Athenaet&n. 
 " The BEST BOOK yet published for the use of Students." Engineer, 
 " Undoubtedly the MOST VALUABLE AND MOST COMPLETE Hand-book en the subject 
 that now exists. " Marine Engineer. 
 
 2. MAGNETISM AND ELECTRICITY (An Advanced Text- 
 
 Book on). Specially arranged for Advanced and " Honours " Students. 
 
 3. APPLIED MECHANICS (An Advanced Text-Book on). 
 
 Vol. I. Comprising Part I. : The Principle of Work and its applica- 
 tions; Part 1 1.: Gearing. Price 75. 6d. SECOND EDITION. 
 
 " FULLY MAINTAINS the reputation of the Author more we cannot say." Pract. 
 Engineer. 
 
 Vol. II. Comprising Parts III. to VI. : Motion and Energy; Graphic 
 Statics; Strength of Materials; Hydraulics and Hydraulic Machinery. 
 Price 75. 6d. {Now ready. 
 
 PROFESSOR JAMIESON'S INTRODUCTORY MANUALS. 
 
 With numerous Illlustrations and Examination Papers. 
 
 1. STEAM AND THE STEAM-ENGINE (Elementary Text- 
 Book on). For First- Year Students. FIFTH EDITION. 3/6. 
 
 " Quite the RIGHT SORT OF BOOK." Engineer. 
 
 " Should be in the hands of EVERY engineering apprentice." Practical Enginttr. 
 
 2. MAGNETISM AND ELECTRICITY (Elementary Text- 
 Book on). For First-Year Students. FOURTH EDITION. 3/6. 
 
 " A CAPITAL TEXT-BOOK . . . The diagrams are an important feature." Schoolmaster. 
 
 "A THOROUGHLY TRUSTWORTHY Text-book. . . . Arrangement as good as well 
 can be. . . . Diagrams are also excellent. . . . The subject throughout treated as an 
 essentially PRACTICAL one, and very clear instructions given." Nature. 
 
 3. APPLIED MECHANICS (Elementary Text-Book on). 
 
 Specially arranged for First-Year Students. SECOND EDITION. 3/6. 
 "Nothing is taken for granted. . . . The work has VERY HIGH QUALITIES, which 
 may be condensed into the one word ' CLEAR.' " Science and Art. 
 
 POCKET-BOOK of ELECTRICAL RULES and TABLES. 
 
 FOR THE USE OF ELECTRICIANS AND ENGINEERS. 
 Pocket Size. Leather, 8s. 6d. Twelfth Edition, revised and enlarged. 
 
 LONDON : EXETER STREET. STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 
 
 " The MOST VALUABLE and USEFUL WORK on Dyeing that has yet appeared in the English 
 language . . . likely to be THE STANDAHD WORK OF REFERENCE for years to come." 
 Textile Mercury. 
 
 In Two Large 8vo Volumes, 920 
 pp., with a SUPPLEMENTARY 
 Volume, containing Specimens 
 of Dyed Fabrics. Handsome 
 Cloth, 45s. 
 
 MANUAL OF DYEING: 
 
 FOR THE USE OF PRACTICAL DYERS, MANUFACTURERS, STUDENTS, 
 AND ALL INTERESTED IN THE ART OF DYEING. 
 
 BY 
 
 E. KNECHT, Ph.D., F.I.C., 
 
 Head of the Chemistry and Dyeing Department of 
 the Technical School, Manchester; Editor of "The 
 Journal of the Society of Dyers and Colourists " 
 
 CHR. RAWSON, F.I.C., F.C.S., 
 
 Late Head of the Chemistry and Dyeing Department 
 of the Technical College, Bradford; Member of 
 Council of the Society of Dyers and Colourists ; 
 
 And RICHARD LOEWENTHAL, Ph.D. 
 
 GENERAL CONTENTS. Chemical Technology of the Textile Fabrics- 
 Water Washing and Bleaching Acids, Alkalies, Mordants Natural 
 Colouring Matters Artificial Organic Colouring Matters Mineral Colours 
 Machinery used in Dyeing Tinctorial Properties of Colouring Matters 
 Analysis and Valuation of Materials used in Dyeing, &c., &c. 
 
 " This MOST VALUABLE WORK . . . will be widely appreciated." Chemical News. 
 
 " This authoritative and exhaustive work . . . the MOST COMPLETE we have yet seen 
 on the subject." Textile Manufacturer. 
 
 " The MOST EXHAUSTIVE and COMPLETE WORK on the subject extant." Textile Recorder. 
 
 " The distinguished authors have placed in the hands of those daily engaged in the dye- 
 house or laboratory a work of EXTREME VALUE and UNDOUBTED UTILITY . . . appeals 
 quickly to the technologist, colour chemist, dyer, and more particularly to the rising dyer 
 of the present generation. A book which it is refreshing to meet with." American Textile 
 Record. 
 
 LONDON : EXETER STREET, STRAND. 
 
28 CHARLES GRIFFIN * CO.'S PUBLICATIONS. 
 
 GETTING GOLD: 
 
 A GOLD-MINING HANDBOOK FOR PRACTICAL MEN. 
 
 BY 
 
 J. C. F. JOHNSON, F.G.S., A.I.M.E., 
 
 Life Member Australasian Mine-Managers' Association. 
 SECOND EDITION. Crown 8vo, Extra. With Illustrations. Cloth, 3s. 6rf. 
 
 " Should prove of the GREATEST VALUE. Almost every page bristles with sugges- 
 tions." Financial News. 
 
 "PRACTICAL from beginning to end . . . deals thoroughly with the Prospecting, 
 Sinking, Crushing, and Extraction of gold." Brit. Australasian. 
 
 " Directors and those interested in the formation of companies would do well to pur- 
 chase Mr. Johnson's book." Mining Journal. 
 
 " The reader, be he miner or novice, will gain from Mr. Johnson's book a GRIP of the 
 gold industry." African Critic. 
 
 "Should be specially commended to all who have any idea of proceeding to the gold 
 fields." Financial Truth. 
 
 " The most striking elements are the numerous ' TIPS ' and USEFUL WRINKLES given." 
 Standard. 
 
 " One is lost in admiration at the wealth of knowledge displayed." Nature. 
 
 " Evidently the well-matured product of a scientist of well-trained and tried experience." 
 South Africa. 
 
 NEW VOLUME OF GRIFFIN'S MINING SERIES. 
 
 Edited by C. LE NEVE FOSTER, D.Sc., F.R.S., 
 
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 Mine Accounts and Mining Book-keeping, 
 
 A Manual for the Use of Students, Managers of 
 
 Metalliferous Mines and Collieries, and 
 
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 With very Numerous Examples taken from the Actual Practice 
 of leading Mining Companies throughout the world. 
 
 BY 
 JAMES G. LAWN, Assoc.RS.M., 
 
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 Kimberley, and Johannesburg. 
 
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 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 29 
 
 WOIE^IECS .BY 
 WALTEE G. M'MILLAN, F.I.C., F.C.S., 
 
 jf Electrical Engineers; latt 
 (as on College, Birmingham. 
 
 Secretary to the Institution of Electrical Engineers; late Lecturer in Metallurgy 
 at Mat 
 
 ELECTRIC SMELTING AND REFINING: 
 
 A PRACTICAL MANUAL OF 
 
 THE EXTRACTION AND TREATMENT OF METALS BY ELECTRICAL METHODS. 
 Being the " ELEKTRO-METALLURGIE " of Dr. W. BORCHERS. 
 
 Translated from the Second German Edition 
 BY WALTER G. M'MILLAN, P.I.O., F.C.S. 
 
 In large 8vo. With Numerous Illustrations and Three Folding-Plates. 
 
 Price 21s. 
 
 *** THE PUBLISHERS beg to call attention to this valuable work. Dr. BORCHERS' 
 treatise is PRACTICAL throughout. It confines itself to ONE branch of Electro-Chemistry, 
 viz. : ELECTROLYSIS, a subject which is daily becoming of more and more importance to 
 the Practical Metallurgist and Manufacturer. Already in the extraction of Aluminium, 
 the refining of Copper, the treatment of Gold and other metals, electrical processes are 
 fast taking the place of the older methods. Dr. BORCHERS' work is acknowledged as the 
 standard authority on the subject in Germany. 
 
 CONTENTS. 
 
 PART I. ALKALIES AND ALKALINE EARTH METALS : Magnesium, 
 Lithium, Beryllium, Sodium, Potassium, Calcium, Strontium, Barium, 
 the Carbides of the Alkaline Earth Metals. PART II. THE EARTH 
 METALS: Aluminium, Cerium, Lanthanum, Didymium. PART III. THE 
 HEAVY METALS : Copper, Silver, Gold, Zinc and Cadmium, Mercury, Tin, 
 Lead, Bismuth, Antimony, Chromium, Molybdenum, Tungsten, Uranium, 
 Manganese, Iron, Nickel, and Cobalt, the Platinum Group. 
 
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 ELECTRO-METALLURGY (A Treatise on): 
 
 Embracing the Application of Electrolysis to the Plating, Depositing, 
 Smelting, and Refining of various Metals, and to the Repro- 
 duction of Printing Surfaces and Art- Work, &c. 
 
 BY WALTER G. M'MILLAN, F.I.C., F.C.S. 
 With numerous Illustrations. Large Crown 8vo. Cloth 10s. 6d. 
 
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 must of necessity prove of great commercial importance. . . . We 
 recommend this manual to ALL who are interested in the PRACTICAL 
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30 CHARLES GRIFFIN & CO.'S PUBLICATIONS. 
 
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 the SAILOR. Crown 8vo, with numerous Illustrations. Handsome 
 
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 GENERAL CONTENTS. Resolution and Composition of Forces Work done 
 
 by Machines and Living Agents The Mechanical Powers: The Lever; 
 
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SCIENTIFIC AND TECHNOLOGICAL WORKS. 31 
 
 MUNRO ft JAMIESON'S ELECTRICAL POCKET-BOOK. 
 
 TWELFTH EDITION, Revised and Enlarged. 
 
 A POCKET-BOOK 
 
 OF 
 
 ELECTRICAL RULES & TABLES 
 
 FOR THE USE OF ELECTRICIANS AND ENGINEERS. 
 BY 
 
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 With Numerous Diagrams. Pocket Size. Leather, 8s. 6d. 
 
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 TELEGRAPHY. 
 
 ELECTRO-CHEMISTRY. 
 
 BATTERIES. 
 
 DYNAMOS AND MOTORS. 
 
 TRANSFORMERS. 
 
 ELECTRIC LIGHTING. 
 
 MISCELLANEOUS. 
 
 LOGARITHMS. 
 
 APPENDICES. 
 
 WONDERFULLY PERFECT. . . . Worthy of the highest commendation we can 
 it." Electrician. 
 
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 AND ENGINEERING. Revised and Corrected by W. DENNIS MARKS, 
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32 OHARLES GRIFFIN A CO.'S PUBLICATIONS. 
 
 Demy 8vo, Handsome cloth, 18s. 
 
 Physical Geology and Palaeontology, 
 
 OJV THE BASIS OF PHILLIPS. 
 
 BY 
 
 HARRY GOVIER SKELEY, F.R.S., 
 
 PROFESSOR OF GEOGRAPHY IN KING'S COLLEGE, LONDON. 
 
 mattb frontispiece in Gbromo*Xitbo0rapb, and 3ilustration6, 
 
 " It is impossible to praise too highly the research which PROFESSOR SKKLEY'S 
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 reputation he already deservedly bears as a Teacher. " Dr. Henry Wood- 
 ward, F.R.S.) in the " Geological Magazine." 
 
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 GEOLOGICAL SURVEY OF GREAT BRITAIN, PAST PRESIDENT OF THB 
 
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 OF XBTKKKNCX." Athtnarum. 
 
 LONDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 33. 
 
 Painting and Decorating: 
 
 A Complete Practical Manual for House 
 Painters and Decorators. 
 
 Embracing the Use of Materials, Tools, and Appliances; the 
 
 Practical Processes involved ; and the General Principles 
 
 of Decoration, Colour, and Ornament. 
 
 BY 
 
 WALTER JOHN PEARCE, 
 
 LECTURER AT THE MANCHESTER TECHNICAL SCHOOL FOR HOUSE-PAINTING AND DECORATING. 
 
 In Crown 8vo. extra. With Numerous Illustrations and Plates 
 (some in Colours), including Original Designs. 12s. 6d. 
 
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 perience, and will he found invaluable by all interested in the subjects 
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 well-known work on " PAINTERS' COLOURS " (see p. 25). 
 
 Open-Air Studies in Botany : 
 
 SKETCHES OF BRITISH WILD FLOWERS IN 
 THEIR HOMES. 
 
 BY 
 
 R. LLOYD PRAEGER, B.A., M.R.I.A. 
 
 Illustrated by Drawing's from Nature by S. Rosamond Praeger, 
 and Photographs by R. Wei eh. 
 
 In Crown 8vo. extra. Handsome Cloth, 7s. 6d. 
 Gilt, for Presentation, 8s. 6d. 
 
 GENERAL CONTENTS. A Daisy-Starred Pasture Under the Hawthorns 
 By the River Along the Shingle A Fragrant Hedgerow A Connemara 
 Bog Where the Samphire grows A Flowery Meadow Among the Corn 
 (a Study in Weeds) In the Home of the Alpines A City Rubbish-Heap 
 Glossary. 
 
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 "Redolent with the scent of woodland and meadow." The Standard. 
 "A Series of STIMULATING and DELIGHTFUL Chapters on Field-Botany." The 
 Scotsman. 
 
 V* Companion-Volume to Prof. Grenville Cole's fascinating " Open-Air Studies in 
 Geology" (see p. 12). 
 
 LONDON: EXETER STREET, STRAND. 
 
34 CHARLES GRIFFIN & CO.'S PUBLICATIONS. 
 
 THIRD EDITION. With Folding Plates and Many Illustrations. 
 Large 8vo. Handsome Cloth. 36s. 
 
 ELEMENTS OP METALLURGY 5 
 
 A PRACTICAL TREATISE ON THE ART OF EXTRACTING METALS 
 
 FROM THEIR ORES, 
 
 BY J. ARTHUR PHILLIPS, M.lNST.C.E., F.C.S., F.G.S., <fec. 
 AND H. BAUERMAN, V.P.G.S. 
 
 GENERAL CONTENTS. 
 
 Refractory Materials. 
 
 Fire- Clays. 
 
 Fuels, &c. 
 
 Aluminium. 
 
 Copper. 
 
 Tin. 
 
 Antimony. 
 
 Arsenic. 
 
 Zinc. 
 
 Mercury. 
 
 Bismuth. 
 
 Lead. 
 
 Iron. 
 
 Cobalt. 
 
 Nickel 
 
 Silver. 
 
 Gold. 
 
 Platinum. 
 
 ** Many NOTABLE ADDITIONS, dealing with new Processes and Developments, 
 will be found in the Third Edition. 
 
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 practical applications of our scientific knowledge to any of our metallurgical 
 operations. " A thenceum. 
 
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 practical Smelter as a Standard Work of Reference. . . . The Illustrations 
 are admirable examples of Wood Engraving." Chemical News. 
 
 POYNTING (J. H., Sc.D., F.R.S., late Fellow 
 
 of Trinity College, Cambridge; Professor of Physics, Mason College, 
 Birmingham) : 
 
 THE MEAN DENSITY OF THE EARTH: An Essay to 
 which the Adams Prize was adjudged in 1893 in the University of 
 Cambridge. In large 8vo, with Bibliography, Illustrations in the Text, 
 and seven Lithographed Plates. 123. 6d. 
 
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 mind. Especially is this the case when the account is given by one who has contributed BO 
 considerably as has Prof. Poynting to our present state of knowledge with respect to a very 
 difficult subject. . . . Remarkably has Newton's estimate been verified by Prof. Poynting." 
 Athenaeum. 
 
 POYNTING and THOMSON: TEXT-BOOK 
 
 OF PHYSICS. (See under Thomson). 
 
 LONDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 35 
 
 WORKS BY 
 
 W, J, MACQUORN RANKINE, LLD,, F.R.S., 
 
 Late Regius Professor of dull Engineering in the University of Glasgow. 
 THOROUGHLY REVISED BY 
 
 W. J. MIL LAB, C.E., 
 
 Late Secretary to the Institute of Engineers and Shipbuilders in Scotland. 
 
 I. A MANUAL OF APPLIED MECHANICS : 
 
 Comprising the Principles of Statics and Cinematics, and Theory of 
 Structures, Mechanism, and Machines. With Numerous Diagrams. 
 Crown Svo, cloth, 12s. 6d. FOURTEENTH EDITION. 
 
 II. A MANUAL OF CIVIL ENGINEERING: 
 
 Comprising Engineering Surveys, Earthwork, Foundations, Masonry, Car- 
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 Harbours, &c. With Numerous Tables and Illustrations. Crown Svo, 
 cloth, 16s. TWENTIETH EDITION. 
 
 III. A MANUAL OF MACHINERY AND MILLWORK : 
 
 Comprising the Geometry, Motions, Work, Strength, Construction, and 
 Objects of Machines, &c. Illustrated with nearly 300 Woodcuts. 
 Crown Svo, cloth, 12s. 6d. SEVENTH EDITION. 
 
 IV. A MANUAL OF THE STEAM-ENGINE AND OTHER 
 PRIME MOVERS: 
 
 With a Section on GAS, OIL, and AIR ENGINES. By BRYAN DONKIN, 
 M.Iust.C.E. Crown Svo, cloth, 12s. 6d. FOURTEENTH EDITION. 
 
 V. USEFUL RULES AND TABLES : 
 
 For Architects, Builders, Engineers, Founders, Mechanics, Shipbuilders, 
 Surveyors, &c. With APPENDIX for the use of ELECTRICAL ENGINEERS. 
 By Professor JAMIESON, F.R.S.E. SEVENTH EDITION. 10s. 6d. 
 
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 %* The " MECHANICAL TEXT-BOOK " was designed by Professor KANKINI as an LMTBO- 
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 LONDON: EXETER STREET, STRAND. 
 
36 CHARLES GRIFFIN <k CO.'S PUBLICATIONS. 
 
 PROF. RANKINJB'S WORKS (Continued). 
 
 VII. MISCELLANEOUS SCIENTIFIC PAPERS. 
 
 Royal 8vo. Cloth, 31s. 6d. 
 
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 With tine Portrait on Steel, Plates, and Diagrams. 
 
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 in our time " Architect. 
 
 CALCAREOUS CEMENTS: 
 
 THEIR NATURE, PREPARATION, AND USES. 
 
 BY GILBERT R. REDGRAVE, Assoc. INST. C.E. 
 
 With Illustrations. 8s. 6d. 
 
 GENERAL CONTENTS. Introduction Historical Review of the Cement 
 Industry The Early Days of Portland Cement Composition of Portland 
 Cement PROCESSES OF MANUFACTURE The Washmill and the Backs 
 Flue and Chamber Drying Processes Calcination of the Cement Mixture 
 Grinding of the Cement Composition of Mortar and Concrete CEMENT 
 TESTING CHEMICAL ANALYSIS of Portland Cement, Lime, and Raw 
 Materials Employment of Slags for Cement Making Scott's Cement, 
 Selenitic Cement, and Cements produced from Sewage Sludge and the 
 Refuse from Alkali Works Plaster Cements Specifications for Portland 
 Cement Appendices (Gases Evolved from Cement Works, Effects of Sea- 
 water on Cement, Cost of Cement Manufacture, &c., &c.) 
 
 " A work calculated to be of GREAT and EXTENDED UTILTTT." Chemical News. 
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 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 37 
 
 AND ITS PRODUGTS: 
 :E:R!LCT:I:CJHLJL, 
 
 BOYERTON REDWOOD, 
 
 F.R.S.E., F.I.C., Assoc. INST. C.E., 
 
 Hon. Con. Mem. of the Imperial Russian Technical Society ; Mem. of the American Chemical 
 
 Society ; Consulting Adviser to the Corporation of London under the 
 
 Petroleum Acts, &c., &c. 
 
 ASSISTED BY GEO. T. HOLLO WAY, F.I.C., Assoc. R.C.S., 
 And Numerous Contributors. 
 
 In Two Volumes, Large 8vo. Price 45s. 
 UGlitb Numerous dfoaps, flMates, anfc Illustrations in tbc 
 
 GENERAL CONTENTS. 
 
 I. General Historical Account of 
 the Petroleum Industry. 
 
 II. Geological and Geographical 
 Distribution of Petroleum and 
 Natural Gas. 
 
 III. Chemical and Physical Pro- 
 
 perties of Petroleum. 
 
 IV. Origin of Petroleum and Natural 
 
 Gas. 
 V. Production of Petroleum, 
 
 Natural Gas, and Ozokerite. 
 VI. The Refining of Petroleum. 
 
 VIII. Transport, Storage, and Dis- 
 tribution of Petroleum. 
 
 IX. Testing of Petroleum. 
 
 .X. Application and Uses of 
 Petroleum. 
 
 XI. Legislation on Petroleum at 
 
 Home and Abroad. 
 XII. Statistics of the Petroleum 
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 most trustworthy and official 
 sources. 
 
 VII. The Shale Oil and Allied In- 
 dustries. 
 
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 comprehensive and explicit account of the geological conditions associated with 
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38 CHARLES GRIFFIN & CO.'S PUBLICATIONS. 
 
 Royal 8uo, Handsome Cloth, 25*. 
 
 THE STABILITY OF SHIPS. 
 
 BY 
 
 SIR EDWARD J. REED, K.C.B., F.R.S., M.P., 
 
 KNIGHT OF THE IMPERIAL ORDERS OF ST. STANILAUS OF RUSSIA; FRANCIS JOSEPH OF 
 AUSTRIA ; MEDJIDIE OF TURKEY ; AND RISING SUN OF JAPAN ; VICE- 
 PRESIDENT OF THE INSTITUTION OF NAVAL ARCHITECTS. 
 
 With numerous Illuszrations ana 7'ables. 
 
 THIS work has been written for the purpose of placing in the hands of Naval Constructors, 
 Shipbuilders, Officers of the Royal and Mercantile Marines, and all Students of Naval Science, 
 a complete Treatise upon the Stability of Ships, and is the only work in the English 
 Language dealing exhaustively with the subj'ect. 
 
 In order to render the work complete for the purposes of the Shipbuilder, whether at 
 home or abroad, the Methods of Calculation introduced by Mr. F. K. BARNES, Mr. GRAY, 
 M. REECH, M. DAYMARD, and Mr. BENJAMIN, are all given separately, illustrated by 
 Tables and worked-out examples. The book contains more than 200 Diagrams, and is 
 illustrated by a large number of actual cases, derived from ships of all descriptions, but 
 especially from ships of the Mercantile Marine. 
 
 The work will thus be found to constitute the most comprehensive and exhaustive Treatise 
 hitherto presented to the Profession on the Science of the STABILITY OF SHIPS. 
 
 " Sir EDWARD REED'S ' STABILITY OF SHIPS ' is INVALUABLE. In it the STUDENT, new 
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 utmost care and accuracy ; the SHIP-DRAUGHTSMAN will find all the methods of calculation at 
 present in use fully explained and illustrated, and accompanied by the Tables and Forms 
 employed ; the SHIPOWNER will find the variations in the Stability of Ships due to differences 
 in forms and dimensions fully discussed, and the devices by which the state of his ships under 
 all conditions may be graphically represented and easily understood ; the NAVAL ARCHITECT 
 will find brought together and ready to his hand, a mass of information which he would other- 
 wise have to seek in an almost endless variety of publications, and some of which he would 
 possibly not be able to obtain at all elsewhere." Steamship. 
 
 "This IMPORTANT AND VALUABLE WORK . . . cannot be too highly recommended to 
 all connected with shipping interests." Iron. 
 
 "This VERY IMPORTANT TREATISE, . . . the MOST INTELLIGIBLE, INSTRUCTIVE, an 
 
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 "The volume is an ESSENTIAL ONB for tha shipbuilding profession." Westtrtinstar 
 Review. 
 
 RICHMOND (H. Droop, F.C.S., Chemist to the 
 
 Aylesbury Dairy Company) : 
 
 DAIRY CHEMISTRY FOR DAIRY MANAGERS : A Practical 
 
 Handbook. ( Griffin's Technological Manuals. ) 
 
 LCNDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 39 
 
 FOURTH EDITION, REVISED. With Additional Illustrations. Price 6s. 
 
 PRACTICAL SANITATION: 
 
 A HAND-BOOK FOR SANITARY INSPECTORS AND OTHERS 
 INTERESTED IN SANITATION. 
 
 By GEORGE REID, M.D., D.P.H., 
 
 Fellow of the Sanitary Institute of Great Britain, and Medical Officer, 
 Staffordshire County Council. 
 
 Witb an appenfcfj on Sanitary 3Law. 
 
 By HERBERT MAN LEY, M.A., M.B., D.P.H., 
 
 Medical Officer of Health for the County Borough of West Bromtvich. 
 
 GENERAL CONTENTS. Introduction Water Supply: Drinking Water, 
 Pollution of Water Ventilation and Warming Principles of Sewage 
 Removal Details of Drainage ; Refuse Removal and Disposal Sanitary 
 and Insanitary Work and Appliances Details of Plumbers Work House 
 Construction Infection and Disinfection Food, Inspection of ; Charac- 
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 Appendix : Sanitary Law ; Model Bye-Laws, &c. 
 
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 In Large 8vo, Handsome Cloth. 12s. 6d. 
 
 DISINFECTION & DISINFECTANTS 
 
 (AN INTRODUCTION TO THE STUDY OF). 
 
 Together with an Account of the Chemical Substances used 
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 BY SAMUEL RIDEAL, D.SC.LOND., F.I.C., F.C.S., 
 
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 With Folding-Plate and Illustrations of the most Approved Modern 
 Appliances. 
 
 %* " Notwithstanding the rapid devetopment of Sanitary Science in this country, there does 
 not exist at the present time in the English language any book which deals exclusively with the 
 composition of DISINFECTANTS. The present volume will, therefore, supply a want which has 
 been felt not only by the chemist and bacteriologist, but also by those who are concerned with th 
 practical work of disinfection. . . ." EXTBACT FROM AUTHOR'S PREFACE. 
 
 "DR. RIDEAL'S volume is bound to prove of GREAT VALUE, both as a PRACTICAL GDIDB and as 
 WORK OF REFERENCE." Pharmaceutical Journal. 
 
 "Aw EXHAUSTIVE TREATISE, dealing -with the WHOLE RANGE of the subject : Disinfection by- 
 Heat, Chemical Disinfectants, Practical Methods, Personal Disinfection, Legal Regulations, and 
 Methods of Analysis ... so very well done and so USEFUL that it will be valued by ALL 
 connected with Sanitation and Public Health." Chemist and Druggist. 
 
 " A book that has long been wanted . . . will prove of VERT GREAT VALUB." Local Govern- 
 ment Journal. 
 
 LONDON: EXETER STREET, STRAND. 
 
40 CHARLES GRIFFIN <k CO.'S PUBLICATIONS. 
 
 GRIFFIN'S "FIRST AID" PUBLICATIONS. 
 
 THIRD EDITION, REVISED. Large Crown Svo. Handsome Cloth. 4s. 
 
 A MANUAL OF AMBULANCE. 
 
 BY J. SCOTT RIDDELL, C.M., M.B., M.A., 
 
 Assistant-Surgeon, Aberdeen Royal Infirmary ; Lecturer and Examiner to the Aberdeen 
 
 Ambulance Association ; Examiner to the St. Andrew's Ambulance Association, 
 
 Glasgow, and the St. John Ambulance Association, London. 
 
 With Numerous Illustrations and Full Page Plates. 
 
 General Contents. Outlines of Human Anatomy and Physiology 
 The Triangular Bandage and its Uses The Roller Bandage and its Uses 
 Fractures Dislocations and Sprains Haemorrhage Wounds Insensi- 
 bility and Fits Asphyxia and Drowning- Suffocation Poisoning Burns, 
 Frost-bite, and Sunstroke Removal of Foreign Bodies from (a) The Eye ; 
 {6) The Ear; (c) The Nose; (d) The Throat; (e) The Tissues Ambulance 
 Transport and Stretcher Drill The After-treatment of Ambulance Patients 
 Organisation and Management of Ambulance Classes Appendix : Ex- 
 amination Papers on First Aid. 
 
 "A CAPITAL BOOK. . . . The directions are BHORT and CLEAR, and testify to the 
 hand of an able surgeon." Edin. Med. Journal. 
 
 " This little volume seems to us about as good as it couldpossibly be. ... Contains 
 practically every piece of information necessary to render First aid. . . . Should find 
 its place in EVKRT HOUSEHOLD LIBRARY." Daily Chronicle. 
 
 " So ADMIRABLE is this work, that it is difficult to imagine how it could be better." 
 Colliery Uuardian. 
 
 Ht Sea. 
 
 Crown &vo, Extra. Handsome Cloth. 6s. 
 
 A MEDICAL AND SURGICAL HELP 
 
 FOR SHIPMASTERS AND OFFICERS 
 
 IN THE MERCHANT NAVY. 
 
 INCLUDING 
 
 FIRST AID TO THE INJURED. 
 
 BY WM. JOHNSON SMITH, F.R.C.S., 
 
 Principal Medical Officer, Seamen's Hospital, Greenwich. 
 
 With Coloured Plates and Numerous Illustrations. 
 
 ",*The attention of all interested in our Merchant Navy is requested to this exceedingly 
 useful and valuable work. It is needless to say that it is the outcome of many years 
 PRACTICAL EXPERIENCE amongst Seamen. 
 
 "SOUND, JUDICIOUS, REALLY HELPFUL." The Lancet. 
 
 "It would be difficult to find a Medical and Surgical Guide more clear and comprehensive 
 than Mr. JOHNSON SMITH, whose experience at the GREENWICH HOSPITAL eminently qualifies 
 him for the task. ... A MOST ATTRACTIVE WORK. . . . We have read it from cover 
 to cover. ... It gives clearly written advice to Masters and Officers in all medical and 
 surgical matters likely to come before them when remote from the land and without a 
 doctor. . . . We RECOMMEND the work to EVKRT Shipmaster and Officer." Liverpool 
 Journal of Commerce. 
 
 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 41 
 
 Sra.es. 
 
 STANDARD WORKSOP REFERENCE 
 
 FOR 
 
 Metallurgists, Mine-Owners, Assayers, Manufacturers, 
 
 and all interested in the deve^pment of 
 
 the Metallurgical Industries. 
 
 EDITED BY 
 
 W. C. ROBERTS-AUSTEN, C.B, F.R.S., 
 
 CHEMIST AND ASSAYER TO THE ROYAL MINT; PROFESSOR OF METALLURGY IN 
 
 THE ROYAL COLLEGE OF SCIENCE. 
 In Large 8vo, Handsome Cloth. With Illustrations. 
 
 1. INTRODUCTION to the STUDY of METALLURGY. 
 
 By the EDITOR. FOURTH EDITION. Revised and Enlarged, with 
 New Illustrations, Micro-Photographic Plates of Different Varieties of 
 Steel, and Folding Plate. 155. 
 
 " No English text-book at all approaches this in the COMPLETENESS with 
 which the most modern views on the subject are dealt with. Professor Austen's 
 volume will be INVALUABLE, not only to the student, but also to those whose 
 knowledge of the art is far advanced." Chemical News. 
 
 " INVALUABLE to the student. . . . Rich in matter not to be readily found 
 elsewhere." Athenceum. 
 
 " This volume amply realises the expectations formed as to the result of the 
 labours of so eminent an authority. It is remarkable for its ORIGINALITY of con- 
 ception and for the large amount of information which it contains. . . . We 
 recommend every one who desires information not only to consult, but to STUDY 
 this work." Engineering. 
 
 " Will at once take FRONT RANK as a text-book." Science and Art. 
 
 " Prof. ROBERTS- AUSTEN'S book marks an epoch in the history of the teaching 
 of metallurgy in this country." Industries. 
 
 2. GOLD (The Metallurgy of). By THOS. KIRKE ROSE, 
 
 D.Sc., Assoc. R.S.M., F.I.C., of the Royal Mint. SECOND EDITION, 
 2is. (See p. 43). 
 
 3. IRON (The Metallurgy of). By THOS. TURNER, 
 
 Assoc. R.S.M., F.I.C., F.C.S. i6s. (Seep. 50). 
 
 Will be Published at Short Intervals. 
 
 4. STEEL (The Metallurgy of). By F. W. HARBORD, 
 
 Assoc R.S.M., F.I.C. 
 
 5. COPPER (The MetaUurgy of). By THOS. GIBB, Assoc. 
 
 Royal School of Mines. 
 
 6. METALLURGICAL MACHINERY: the Application of 
 
 Engineering to Metallurgical Problems. By HENRY CHARLES JENKINS, 
 Wh.Sc., Assoc.R-S.M., Assoc. M.Inst.C.E., of the Royal Mint. 
 
 7. ALLOYS. By the EDITOR. 
 
 %* Other Volumes in Preparation. 
 
 LONDON: EXETER STREET, STRAND. 
 
CHARLES GRIFFIN <k CO. 'S PUBLICATIONS. 
 
 SECOND EDITION, Revised and Enlarged. 
 In Large 8vo, Handsome cloth, 34$- 
 
 HYDRAULIC POWER 
 
 AND 
 
 HYDRAULIC MACHINERY. 
 
 BY 
 
 HENRY ROBINSON, M. INST. C.E., F.G.S., 
 
 FELLOW OF KING'S COLLEGE, LONDON; PROF. OF CIVIL ENGINEERING, 
 KING'S COLLEGE, ETC., ETC. 
 
 TMlitb numerous TKaooDcuts, and Sit^*nine plates. 
 
 GENERAL CONTENTS. 
 
 Discharge through Orifices Gauging Water by Weirs Flow of Water 
 through Pipes The Accumulator The Flow of Solids Hydraulic Presses 
 and Lifts Cyclone Hydraulic Baling Press Anderton Hydraulic Lift 
 Hydraulic Hoists (Lifts) The Otis Elevator Mersey Railway Lifts City 
 and South London Railway Lifts North Hudson County Railway Elevator 
 Lifts for Subways Hydraulic Ram PearsalPs Hydraulic Engine Pumping- 
 Engines Three- Cylinder Engines Brotherhood Engine Rigg's Hydraulic 
 Engine Hydraulic Capstans Hydraulic Traversers Movable Jigger Hoist 
 Hydraulic Waggon Drop Hydraulic Jack Duckham's Weighing Machine 
 Shop Tools Tweddell's Hydraulic Rivetter Hydraulic Joggling Press 
 Tweddell's Punching and Shearing Machine Flanging Machine Hydraulic 
 Centre Crane Wrightson's Balance Crane Hydraulic Power at the Forth 
 Bridge Cranes Hydraulic Coal-Discharging Machines Hydraulic Drill 
 Hydraulic Manhole Cutter Hydraulic Drill at St. Gothard Tunnel Motors 
 with Variable Power Hydraulic Machinery on Board Ship Hydraulic Points 
 and Crossings Hydraulic Pile Driver Hydraulic Pile Screwing Apparatus 
 Hydraulic Excavator Ball's Pump Dredger Hydraulic Power applied to 
 Bridges Dock-gate Machinery Hydraulic Brake Hydraulic Power applied 
 to Gunnery Centrifugal Pumps Water Wheels Turbines Jet Propulsion 
 The Gerard-Barr^ Hydraulic Railway Greathead's Injector Hydrant Snell's 
 Hydraulic Transport System Greathead's Shield Grain Elevator at Frank- 
 fort Packing Power Co-operation Hull Hydraulic Power Company 
 London Hydraulic Power Company Birmingham Hydraulic Power System 
 Niagara Falls Cost of Hydraulic Power Meters Schonheyder's Pressure 
 Regulator Deacon's Waste-Water Meter. 
 
 " A Book of great Professional Usefulness." Iron. 
 
 V The SECOND EDITION of the abore important work has been thoroughly rerised and 
 brought up to date. Many new full-page Plates hare been added the number being 
 increased from 43 in the First Edition to 9 in the present. Full Proapectus, giring A 
 description of the Plates, may be had on application to the Publishers. 
 
 LONDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 43 
 
 GRIFFIN'S METALLURGICAL SERIES. 
 
 SECOND EDITION. Large 8vo. Handsome Cloth. 21s. 
 
 THE METALLURGY OF GOLD. 
 
 BY 
 
 T. KIRKE ROSE, D.Sc., Assoc.R.S.M., F.I.C., 
 
 Assistant Assayer of the Royal Mint. 
 
 Revised and partly Re-written. Including the most recent Improve- 
 ments in the Cyanide Process, and a new Chapter on Economic 
 Considerations (Management, Cost, Output, &c.). With 
 Frontispiece and additional Illustrations. 
 
 LEADING FEATUEES. 
 
 1. Adapted for all who are interested in the Gold Mining Industry, being 
 free from technicalities as far as possible ; of special value to those engaged in 
 the industry viz. , mill-managers, reduction-officers, &c. 
 
 2. The whole ground implied by the term " Metallurgy of Gold " has been 
 covered with equal care ; the space is carefully apportioned to the various 
 branches of the subject, according to their relative importance. 
 
 3. The MAcARTHDR-FoKREST CYANIDE PROCESS is fully described for the 
 first time. By this process over 2,000,000 of gold per annum (at the rate of) is 
 now being extracted, or nearly one-tenth of the total world's production. The 
 process, introduced in 1887, has only had short newspaper accounts given of it 
 previously. The chapters have been submitted to, and revised by, Mr. 
 MacArthur, and so freed from all possible inaccuracies. 
 
 4. Among other new processes not previously described in a text-book are 
 (1) The modern barrel chlorination process, practised with great success in 
 Dakota, where the Black Hills district is undergoing rapid development owing 
 to its introduction. (2) New processes for separating gold from silver viz., the 
 new Gutzkow process, and the Electrolytic process ; the cost of separation is 
 reduced by them by one-half. 
 
 5. A new feature is the description of EXACT METHODS employed in particular 
 extraction works Stamp-batteries of South Africa, Australia, New Zealand, 
 California, Colorado, and Dakota; Chlorination works also, in many parts of 
 the world ; Cyanide works of S. Africa and New Zealand. These accounts are 
 of special value to practical men. 
 
 6. The bibliography is the first made since 1882. 
 
 " Dr. KOSE gained his experience in the Western States of America, but he has secured 
 details of gold-working from ALL PARTS of the world, and these should be of GREAT SERVICE 
 to practical men. . . . The four chapters on Chlorination, written from the point of view 
 alike of the practical man and the chemist, TEEM WITH CONSIDERATIONS HITHERTO UNRECOG- 
 NISED, and constitute an addition to the literature of Metallurgy, which will prove to b of 
 classical value." Nature. 
 
 "The most complete description of the chlorination process which has yet been published. 
 Mining Journal. 
 
 LONDON: EXETER STREET, STRAND. 
 
44 CHARLES GRIFFIN & CO.'S PUBLICATIONS. 
 
 Companion-Volume to MM. Knecht and Rawson's "Dyeing." 
 
 TEXTILE PRINTING: 
 
 A PRACTICAL MANUAL. 
 
 Including the Processes Used in the Printing of 
 
 COTTON, WOOLLEN, SILK, and HALF-SILK FABRICS. 
 
 Br C. F. SEYMOUR ROTHWELL, F.C.S., 
 
 Mem. Soe. of Chemical Industries; late Lecturer at the Municipal Technical School, Manchester. 
 In Large 8vo, with Illustrations and Printed Patterns. Price 2 is. 
 
 General Contents. Introduction The Machinery Used in Textile Printing 
 Thickeners and Mordants The Printing of Cotton Goods The Steam Style 
 Colours Produced Directly on the FibreDyed Styles Padding Style 
 Resist and Discharge Styles The Printing of Compound Colourings, &c. 
 The Printing of Woollen Goods The Printing of ^ilk Goods Practical 
 Recipes for Printing Appendix Useful Tables Patterns. 
 
 "BY FAR THE BEST and MOST PRACTICAL BOOK on TEXTILE PRINTING which has yet been 
 brought out, and will long remain the standard work on the subject. It is essentially 
 practical in character." Textile Mercury. 
 
 " THE MOST PRACTICAL MANUAL of TEXTILE PRINTING which has yet appeared. We have 
 no hesitation in recommending it." The Textile Manufacturer. 
 
 " UNDOUBTEDLY the book is THE BEST which has appeared on TEXTILE PRINTING, and 
 worthily lorms a Companion-Volume to ' A Manual on Dyeing.' "The Dyer and Calico 
 Printer. 
 
 SCHWACKHOFER and BROWNE: 
 
 FUEL AND WATER: A Manual for Users of Steam and Water. 
 By Prof. FRANZ SCHWACKHOFER of Vienna, and WALTER 
 R. BROWNE, M.A., C.E., late Fellow of Trinity College, Cambridge. 
 Demy 8vo, with Numerous Illustrations, g/. 
 
 GENERAL CONTENTS. Heat and Combustion Fuel, Varieties of Firing Arrange- 
 ments : Furnace, Flues, Chimney The Boiler, Choice of Varieties Feed-water 
 Heaters Steam Pipes Water: Composition, Purification Prevention of Scale, &c., &c. 
 
 "The Section on Heat is one of the best and most lucid ever written." Engineer. 
 " Cannot fail to be valuable to thousands using steam power." Railway Engineer. 
 
 SHELTON-BEY (W. Vincent, Foreman' to the 
 
 Imperial Ottoman Gun Factories, Constantinople) : 
 
 THE MECHANIC'S GUIDE : A Hand- Book for Engineers and 
 Artizans. With Copious Tables and Valuable Recipes for Practical Use. 
 Illustrated. Second Edition, Crown 8vo. Cloth, 7/6. 
 
 LONDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 45 
 
 Thirteenth Edition. Price 21s. 
 
 Demy 8vo, Cloth. With Numerous Illustrations, reduced from 
 Working Drawings. 
 
 A MANUAL OP 
 
 MARINE ENGINEERING: 
 
 COMPRISING THE DESIGNING, CONSTRUCTION, AND 
 WORKING OF MARINE MACHINERY. 
 
 By A. E. S E A T N, M. Inst. C. E., M. Inst. Meeh. E., 
 M.Inst.N.A. 
 
 GENERAL CONTENTS. 
 
 Part I. Principles of Marine 
 Propulsion. 
 
 Part XL-Principles of Steam Valves, &e. 
 
 Engineering. 
 
 Part III. Details of Marine 
 Engines: Design and Cal- 
 
 culations for Cylinders, 
 Pistons, Valves, Expansion 
 
 Part IV. Propellers. 
 Part V. Boilers. 
 Part VI. Miscellaneous. 
 
 V The THIRTEENTH EDITION includes a Chapter on WATER- TUBE BOILERS, 
 with Illustrations of the leading Types. 
 
 " In the three-fold capacity of enabling a Student to learn how to design, construct, 
 and work a Marine Steam- Engine. Mr. Seaton's Manual has NO RIVAL." Times. 
 
 "The important subject of Marine Engineering is here treated with the THOROUGH- 
 NESS that it reauires. No department has escaped attention. . . . Gives the 
 results of mucn close study and practical work." Engineering. 
 
 " By far the BEST MANUAL in existence. . . . Gives a complete account of the 
 methods of solving, with the utmost possible economy, the problems before the Marine 
 Engineer." Athenaeum. 
 
 " The Student, Draughtsman, and Engineer will find this work the MOST VALUABLE 
 HANDBOOK of Reference on the Marine Engine now in existence." Marine Engineer. 
 
 FOURTH EDITION. With Diagrams. Pocket-Size, Leather. 8s. 6d. 
 A POCKET-BOOK OF 
 
 MARINE ENGINEERING RULES AND TABLES, 
 
 FOR THE USE OF 
 
 Marine Engineers, Naval Architects, Designers, Draughtsmen, 
 Superintendents and Others. 
 
 BY 
 
 A. E. SEATON, M.I.O.E., M.I.Mech.E., M.I.N.A., 
 
 AND 
 
 H. M. ROUNTHWAITE, M.I.Mech.E., M.I.N.A. 
 
 "ADMIRABLY FULFILS its purpose." Marine Engineer. 
 LONDON: EXETER STREET, STRAND. 
 
46 CHARLES GRIFFIN Jc CO. 1 8 PUBLICATIONS. 
 
 WORKS BY A. HUMBOLDT SEXTON, F.I.C., F.C.S., 
 
 Professor of Metallurgy in the Glasgow and West of Scotland Technical College. 
 
 In Large Crown Svo, Handsome Cloth, 6s. 
 
 ELEMENTARY METALLURGY 
 
 (A TEXT-BOOK OF). 
 
 Including the Author's PRACTICAL LABORATORY COURSE. 
 With, Numerous Illustrations. 
 
 GENERAL CONTENTS. Introduction Properties of the Metals Combustion 
 Fuels Refractory Materials Furnaces Occurrence of the Metals in Nature Pre- 
 paration of the Ore for the Smelter Metallurgical Processes Iron : Preparation of 
 Pig Iron Malleable Iron Steel Mild Steel Copper Lead Zinc and Tin Silver 
 Gold Mercury Alloys Applications of ELECTRICITY to Metallurgy LABORA- 
 TORY COURSE WITH NUMEROUS PRACTICAL EXERCISES. 
 
 " The volume before us FULLY ENHANCES and confirms PROF. SEXTON'S reputa- 
 tion. . . . Just the kind of work lor Students COMMENCING the study of Metal- 
 lurgy, or for ENGINEERING Students requiring a GENERAL KNOWLEDGE of it, or 
 for ENGINEERS in practice who like a HANDY WORK of REFERENCE. To all three 
 classes we HEARTILY commend the work." Practical Engineer. 
 
 " EXCELLENTLY got-up and WELL-ARRANGED. . . . Iron and copper well 
 explained by EXCELLENT diagrams showing the stages of the process from start to 
 finish. . . . The most NOVEL chapter is that on the many changes wrought 
 in Metallurgical Methods by ELECTRICITY." Chemical Trade Journal. 
 
 " Possesses the GREAT ADVANTAGE of giving a COURSE OF PRACTICAL WORK." 
 Mining Journal. 
 
 Sexton's (Prof.) Outlines of Quantitative Analysis. 
 
 FOR THE USE OF STUDENTS. 
 With Illustrations. FOURTH EDITION. Crown Svo, Cloth, 3s. 
 
 " A COMPACT LABORATORY GUIDE for beginners was wanted, and the want has 
 been WELL SUPPLIED. ... A good and useful book." Lancet. 
 
 Sexton's (Prof.) Outlines of Qualitative Analysis. 
 
 FOR THE USE OF STUDENTS. 
 With Illustrations. THIRD EDITION. Crown Svo, Cloth, 3s. 6d. 
 
 " The work of a thoroughly practical chemist." British Medical Journal. 
 " Compiled with great care, and will supply a want." Journal of Education. 
 
 LONDON: EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 47 
 
 In Large 8vo. Handsome Cloth. Price 21s. 
 
 BREWING: 
 
 (THE PRINCIPLES AND PRACTICE OF). 
 
 FOR THE USE OF STUDENTS AND PRACTICAL MEN. 
 
 BY 
 
 WALTER J. SYKES, M.D., D.P.H., F.I.C., 
 
 EDITOR OF "THE ANALYST." 
 With Illustrations and Plates. 
 
 %* This work is intended to present a description of the FUNDA- 
 MENTAL PRINCIPLES on which the Art of Brewing is based, and also a bird's 
 eye view of that Art as carried on in accordance with THE BEST AND MOST 
 
 SCIENTIFIC MODERN METHODS. 
 
 In Large 8vo. Handsome Cloth. With numerous Illustrations. 
 
 TECHNICAL MYCOLOGY: 
 
 THE UTILIZATION OF MICRO-ORGANISMS IN THE 
 
 ARTS AND MANUFACTURES. 
 
 A Practical Handbook on Fermentation and Fermentative Pro- 
 cesses for the Use of Brewers and Distillers, Analysts, 
 Technical and Agricultural Chemists, and all 
 interested in the Industries dependent 
 
 on Fermentation. 
 BY DR. FRANZ LAFAR, 
 
 Of the Eoyal Experimental Station for Industries dependent on Fermentation, 
 Hohenheim, near Stuttgart. 
 
 With an Introduction by DK. EMIL CHR. HANSEN, Principal of the 
 
 Carlsberg Laboratory, Copenhagen. 
 
 TRANSLATED BY CHARLES T. C. SALTER. 
 
 In Two Volumes, fold Separately. 
 
 *** It is hoped that the English version of the First Volume of this novel and 
 important work will be issued in the autumn of 1897 ; that of the Second, during 1898. 
 The extraordinary roles played by Micro-organisms in Brewing and Distilling in the 
 manufacture of Sugar, of Vinegar, and Acetic Acid in Tanning and Tobacco Manufac- 
 turein Agricultural Industries and the Processes conuected with the Dairy : Souring of 
 Cream, Cheese-Ripening, &c., &c. combine to make Dr. Lafar's Text-Book one of great 
 value and interest to a very wide circle of readers. 
 
 LONDON : EXETER STREET, STRAND. 
 
48 CHARLES GRIFFIN <* CO.'S PUBLICATIONS. 
 
 WORKS BY PROF. ROBERT H. SMITH, Assoe.M.I.C.E., 
 
 M.I.M.E., M.I.E1.E., M.Fedl.Mi.E., Whit. Sch., M.Ord.Meiji. 
 
 MEASUREMENT CONVERSIONS 
 
 (English and French) : 
 28 GRAPHIC TABLES OR DIAGRAMS. 
 
 Showing at a glance the MUTUAL CONVERSION of MEASUREMENTS 
 
 in DIFFERENT UNITS 
 Of Lengths, Areas, Volumes, Weights, Stresses, Densities, Quantities 
 
 of Work, Horse Powers, Temperatures, &c. 
 
 For the use of Engineers, Surveyors, Architects, and Contractors. 
 
 In 4to, Boards. 7s. 6d. 
 
 %* Prof. SMITH'S CONVERSION-TABLES form the most unique and com- 
 prehensive collection ever placed before the profession. By their use much 
 time and labour will be saved, and the chances of error in calculation 
 diminished. It is believed that henceforth no Engineer's Office will be 
 considered complete without them. 
 
 " The work is IN VALUABLE." Colliery Guardian. 
 
 " Ought to be in EVERT office where even occasional conversions are required. . . . Prof. 
 SMITH'S TABLES form very EXCELLENT CHECKS on results. ... A VERY USEFUL and good 
 set of diagrams." Electrical Review. 
 
 "Prof. Smith deserves the hearty thanks, not only of the ENGINEER, hut of the COMMERCIAL 
 WORLD, for having smoothed the way for the ADOPTION of the METRIC SYSTEM of MEASUREMENT, 
 a subject which is now assuming great importance as a factor in maintaining our HOLD upon 
 FOREIGN TRADE. There can be no doubt that the antiquated system of Weights and Measures 
 used in this country is doomed to be superseded by the much simpler method of DECIMAL 
 MEASUREMENT. The sooner this is recognised, the better." The Machinery Market. 
 
 THE CALCULUS FOR ENGINEERS 
 
 AND PHYSICISTS, 
 Applied to Technical Problems. 
 
 WITH EXTENSIVE 
 
 CLASSIFIED REFERENCE LIST OF INTEGRALS. 
 By PROF. ROBERT H. SMITH. 
 
 ASSISTED BY 
 
 ROBERT FRANKLIN MUIRHEAD, 
 
 M.A., B.Sc. (Glasgow), B.A. (Cambridge), 
 
 Formerly Clark Fellow of Glasgow University, and Lecturer on Mathematics at 
 Mason College. 
 
 In Crown 8vo, extra, with Diagrams and Folding -Plate, 8s. 6d. 
 LONDON : EXETER STREET, STRAND. 
 
SCIENTIFIC AND TECHNOLOGICAL WORKS. 49 
 
 By PROFESSORS J. J. THOMSON & POYNTING. 
 
 In Large 8vo. Fully Illustrated. 
 
 A TEXT-BOOK OF PHYSICS: 
 
 COMPRISING 
 
 PROPERTIES OF MATTER; HEAT; SOUND AND LIGHT; 
 MAGNETISM AND ELECTRICITY. 
 
 BY 
 
 J. H. POYNTING, J. J. THOMSON, 
 
 SC.D., F.R.S., AND M - A -' F.B.8., 
 
 bate Fellow of Trinity College, Cambridge; Fellow of Trinity College, Cambridge; Prof. 
 
 Professor of Physics, Mason College, of Experimental Physics in the University 
 
 Birmingham. of Cambridge. 
 
 THIRD EDITION, Revised and Enlarged. Pocket-Size, Leather, also for Office Use, Cloth, 12. 6d 
 
 BOILERS, MARINE AND LAND. 
 
 THEIR CONSTRUCTION AND STRENGTH. 
 
 A HANDBOOK OF RULES, FORMULAE, TABLES, &c., RELATIVE TO MATERIAL, 
 
 SCANTLINGS, AND PRESSURES, SAFETY VALVES, SPRINGS, 
 
 FITTINGS AND MOUNTINGS, &c. 
 
 jfor tbe < 0l5e ot all Stcam* < d0cr5, 
 BY T. W. TRAILL, M. INST. 0. E., F. E. R. N., 
 
 Late Engineer Surveyor-in-Chief to the Board of Trade. 
 
 %* To THE THIRD EDITION MANY NEW TABLES have been added. 
 
 " Very unlike any of the numerous treatises on Boilers which have preceded it. ... Really 
 useful. . . . Contains an ENORMOUS QUANTITY OP INFORMATION arranged in a very convenient 
 form. . . . Those who have to design boilers will find that they can settle the dimensions for any 
 ifiven pressure with almost no calculation with its aid. ... A MOST USEFUL VOLUME . . 
 supplying information to be had nowhere else." The Engineer. 
 
 " As a handbook of rules, formulae, tables, <fec., relating to materials, scantlings, and pressure*, thii 
 work will prove MOST USEFUL. The name of the Author is a sufficient guarantee for its accuracy. It 
 will save engineers, inspectors, and draughtsmen a vast amount of calculation." Mature. 
 
 " By such an authority cannot but prove a welcome addition to the literature of the subject. . . . 
 We can strongly recommend it as being the MOST COMPUTE, eminently practical work on the subject." 
 Marine Engineer. 
 
 To the engineer and practical boiler-maker it will prove INVALUABLE. The tables in all pro- 
 bability are the most exhaustive yet published. . . . Certainly deserves a place on the shelf in 
 the drawing office of every boiler shop. Practical Engineer. 
 
 LONDON : EXETER STREET, STRAND. 
 
CHARLES GRIFFIN & CO. 'S PUBLICATIONS. 
 
 GRIFFIN'S METALLURGICAL SERIES. 
 
 THE METALLURGY OF IRON. 
 
 BT 
 
 THOMAS TURNER Assoc.R.S.M., F.I.C., 
 
 Director of Technical Instruction to the Staffordshire County Council. 
 
 IN LARGE 8vo, HANDSOME CLOTH, WITH NUMEROUS ILLUSTRATIONS 
 (MANY FROM PHOTOGRAPHS). PRICE 16s. 
 
 GENERAL CONTENTS. 
 
 Early History of Iron. 
 
 Modern History of Iron. 
 
 The Age of Steel. 
 
 Chief Iron Ores. 
 
 Preparation of Iron Ores. 
 
 The Blast Furnace. 
 
 The Air used in the Blast Furnace. 
 
 Reactions of the Blast Furnace. 
 
 The Fuel used in the Blast Furnace. 
 
 Slags and Fluxes of Iron Smelting. 
 
 Properties of Cast Iron. 
 
 Foundry Practice. 
 
 Wrought Iron. 
 
 Indirect Production of Wrought 
 
 Iron. 
 
 The Puddling Process. 
 Further Treatment of Wrought 
 
 Iron. 
 
 Corrosion of Iron and steel. 
 
 *' A MOST VALUABLE SUMMARY of useful knowledge relating to every method and 
 stage in the manufacture of cast and wrought iron down to the present moment . . . 
 particularly rich in chemical details. ... An EXHAUSTIVE and REALLY NEKDED 
 compilation by a MOST CAPABLE and THOROUGHLY UP-TO-DATE metallurgical 
 authority." Bulletin of the American Iron and Steel Association. 
 
 " This is A DKLIGHTFUL BOOK, giving, as it does, reliable information on a subject 
 becoming every day more elaborate. . . . The account of the chief iron ores is, 
 like the rest of this work, RICH in detail. . . . Foundry Practice has been made 
 the subject of considerable investigation by the author, and forms an interesting and 
 able chapter." Colliery Guardian. 
 
 " Mr. Turner's work comes at an opportune moment and in answer to a REAL 
 DEMAND. ... A THOROUGHLY USEFUL BOOK, which brings the subject UP TO 
 DATE. The author has produced an EMINENTLY READABLE BOOK. . . . What- 
 ever he describes, he describes well. . . . There is much in the work that will be 
 of GREAT VALUE to those engaged in the iron industry." Mining Journal. 
 
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