^s. Sci. ILCRo MEMOIRS OF THE Gf:^OLOGICAL SURVEY. SCOTL AJSTD. , ,, l^sra. — -- UNIVERSITY Of ^A■^0S»,'^ THE filVBU.!Of;. OIL-SHALES OF THE LOTHIANS PART I, THE GEOLOGY OF THE OIL-SHALE FIELDS. By E. G. CAEEUTHEES, BASED ON THE WORK OF H. M. Cadell and J. S. Grant Wilson. PART 11. METHODS OF WORKING THE OIL-SHALES. By W. CALDWELL. PART III. THE CHEMISTRY OF THE OIL-SHALES. By D. E. STEUAET, "FJ.C. SECOND EDITION. PUBLISHED BY ORDER OF THE LORDS COMMISSIONERS OF HIS MAJESTY S TREASURY. EDINBURGH : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By MORRISON & GIBB LIMITED, At Tan field. And to be purchased from E. STANFORD, 12, 13 and 14 Long Acre, London; W. & A. K. JOHNSTON, Ltd., 2 St. Andrew Square, Edinburgh; HODGES, FIGGIS & CO., Ltd., 104 Grafton Street, Dudlin. From any Agent for the sale of Ordnance Survey Maps ; or through any Bookseller from T. FISHER UNWIN, 1 Adelphi Terrace, London, W.C, who is the sole Wholesale Agent to the Trade outside the County o^ London. 1912. Price Tico SJnlUnrjs and Sixpence. LIST OI PUBIilCAT ONS OF THE GEOLOGICAL SURVEY O^ SCOTLAND. Geclogrical Map (25 miles to lue iutU) of the British Isl onds. Pri, , LoJciurari, 2s. ; Uiicolonreil, Is. Maps on the Scale of Four Milea to One Inch. Shett 12. Pert hsliiie, Forl'ai -ii'.re, KiiicMrdine.hire, kc. 15. Fii'eshire, Edinbti: I -I''-- Fladdington.shire, .'.c 16. Galloway and par •. ^c. 17. Roxburghshire, IJ , cs:c. Prill tod in (Jolours. la. Hd. each. Maps on One-inch Scale, (lolour-printed.) Arraii. (New edition.) 2*. (See refcrencpo to Sheets IC and. 21 und'?T Hand-uo!ouifd Maps.) ,1^ r -r District (embracing pr^rts of Dumbiii-tonshire, Lspark.shire t^- . v-iiire and Stirlingshire) 25. ,y> ^. L'i. Ml. ']":: de, Jura and Nartli Kintyre 2s. 6d. 62. Edinburghshire, Linlith>;ow.ihii< , Fifeshire and Peeblesshire .parts of). (New edition.) 2s. Pa. 33. Hatlclingtonshirc .*ud parts of Edinburghshire and Berwickshire. cNew edition.) 2«. 6d. 35. Colonsay and Oronsay. with part of the Rosj of Mull. 2s. 6d. 65. Aberdeenshire, S.W. ; Ptfr^.i^hiie, N.E. : Forfiirshii., l^.W. 2s, 6d. 71. Glenelg, Lochalsh and the South-East part of Skye. 2.W. Division. 9b. ad. 5. Iviikcudbrightshire, Southern Districts. 13s. 3d. 6. Kirkcudbrighuhi»-e. E. uaargiu ; Dumfriesshire, S. margin. 3s. 6d. 7. Ayrshire, Snuth-Woi^t' rn Districts. 7s. 3a. 8. Kirkcudbrightshire, .*vjn:bire n"d Wigtownshire (parts of). 16«. 'Ad. 9. Kirkendbiightshire, N.E. ; Dumfriesshire, S.W. lis 9d. 10. Dumf'iesshire. 10s. 3d. 11. Roxburghshire and Duinfn'eeehire (parts of). 5s. 'Jd. 12. Argyllshire (Kintyrc, S. half of), lis. 13. Ayrshi '■, Turnberry Point, and S. part of Arran (Solid, third edition, and Drilt, hrst edition). 7s. Hd. (See Colour printed Map of Arran.) 14. Ayrshire, Central Districts, lis. 15. Dumfriesshire, N.W. ; Ayrshire, S.E. ; and Lanarkshire, S. lis. 16. Dumfries, Selkirk, Peebles, Lauark and Roxburgh shires (parts oO- ii». 17. Rorcburghshire, Selkirkshire and Dumfriesshire (part. *" ^- ?-' 18. Roxburghshire. E. part. 2s. 9d. 19. Argyllsliire (S. part of Islay). 10s. 3d. 20. Argyllshire (Kiutyre, Gigha I., part of Tslay). 9s. 6d. 21. Argyllshire ; Arran, Central and N. part ; Lutp, S. part ; • .'umbraes, Ayrshire (part of N.W.) Solid and Drift, first edition". 16s. 3d. (See Colour-printed Map of Anau.j 22. Ayrshire, RoufrewsLire, Lanarkshire (parts of). 14s. 9d. 23. Lanarkshire, Central Districts , Ayrshire (part of W.). 19s. 3d. 24. Peeblesshire, Lanarkshire, Edir'jurgh.shire. Selkirkshire (parts of). 8s. 9d. 25. Berwick, Eoxlmrgh, Selkirk, and Edinburgh shires (parts of). 8s. 9d. 26. Berwickshire and Roxbuighshire (part^ of). 3s. 3d. 27. Argyllshire ; parts oi Islay, Jura and Oronsay. 8s. 29. Argyllrhire, Av rshirc. Buteshire, Dumbartonshire and Renfrewshire (pirt? of). 21s. '6d. SO. Renfrewshire; parts of Dumbarton. Stirling, Lanark aud Ayr. 16s. Zd. 31. Lanarkshire, Stirlingshire, Linh' ' .w^hire, Dumbartonshire, Ediaburgh- shire (parts of). 16.'». 3d. 34. Eastern Berwickshire. .Ss. 6d. 36. Seaboard of Mid Argyll (Solid ..ud Drift editions). 16s. 3d. 37. Mid Argyll (Solid and Drift editions). 25.'!. M. 88. PerrL.ib'r-, Stirlingshire, Dumbartonshire, Argyllshire (parts of). I4s. 9d. 39. Perta-liire, Clackmannanshire, Stirlingshire and Fifeshire (parts of). 17s. 9d. 40. Fife =ind Kinross. 14s. 'Jd. •il. Fife, East part ; Haddingtonshire, North part. 5s. 9d. 45. Ari'vllshire, Country near Oban and Dalmally (Solid and Drift editions). "25s. 3d. 46. Perthshire, Argyllshire (parts of). 19s. 3d. 47. Perthshire. 16s. 3d. 43. Parthshire, Forfarshire and Fifeshire (parts of), lis. 49. Forfarshire and Fifeshire (parts of). 5s. 55. Perthshire (Solid and Drift editions). 22s. 3d. and 26s. 3i 56. Perthshire, Forfar^bire ^parts of). 22.^ 3d. 57. Forfarshire and Kincardineshire (pares of). 10s. 3d. ' Wt 31/51/66 11-12—1000 MEMOIRS OF THE GEOLOGICAL SURVEY. SCOTLAND. 1^33*=^ ~^ THE OIL-SHALES OF THE LOTHIANS. PART I. THE GEOLOGY OF THE OIL-SHALE FIELDS. By R. G. CAERUTHEES, BASED ON THE WORK OF H. M. Cadell and J. S. Grant Wilson. PART 11. METHODS OF WORKING THE OIL-SHALES. By W. CALDWELL. PART III. THE CHEMISTRY OF THE OIL-SHALES. By D. E. STEUAET, F.I.C. SECOND EDITION. PUBLISHED BY OKDER OF THE LORDS COMMISSIONERS OF HIS MAJESTY S TREASURY. EDINBURGH : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By MORRISON & GIBB LIMITED, At Tanfield. And to be purchased from E, STANFORD, 12, 13 and 14 Long Acre, London; W. & A. K. JOHNSTON, Ltd., 2 St, Andrew Square, Edinburgh; HODGES, FIGGIS & CO., Ltd., 104 Grafton Street, Dublin, From any Agent for the sale of Ordnance Survey Maps ; or through any Bookseller from T. FISHER UNWIN, 1 Adklvhi Terrace, London, W.C., who is the sole Wholesale Agent to the Trade outside the County of London. 1912. Price Tti'o SliiJlinris and Sirppnce. PREFACE TO FIRST EDITION. -♦ — The following Memoir on the Oil-Shale industry of Scotland is divided into three parts, and treats of the subject both in its geological and technological aspects. Part I. treats of the Geology of the Oil-Shale fields of the Lothians, and is the joint work of Mr. H. M. Cadell and Mr. .J. S. Grant Wilson. After the opening up of the oil-shale industry it became necessary to re-survey the portions of Midlothian and Lin- lithgowshire in which the shales occur. This work was done by Mr. Cadell, who, since its completion in 1887, has possessed an unrivalled knowledge of the geological structure of the various shale-fields. It is therefore a source of gratification that, notwithstanding his retirement from the Geological Survey, we have been able to secure his services in the preparation of this volume. The recent revision of the area in connection with the re-survey of the Scottish coal-fields has fallen to the lot of Mr. J. S. Grant Wilson, who thus natiu:ally becomes associated with his former colleague. Part II., which deals with the methods of working the oil-shales, and is, therefore, of a technological character, has been executed by Mr. W. Caldwell, whose training as a mining engineer and whose experience as mining manager in the Pumpherston field have given him special qualifications for the task. Part III. is concerned with the treatment of the material after its extraction from the mine, with the products obtained from it, and with the statistics of the industry. This is the work of Mr. D. R. Steuart, chemist to the Broxburn Oil Company, who is recognised as a leading authority on this branch of enquiry. Special thanks are due to Dr. Leonard Dobbin, chief assistant to Professor Crum Brown, F.R.S., The University, Edinburgh, for valuable suggestions in connection with the part dealing with the chemistry of the oil-shales, and for kind assistance in revising the proof-sheets. The Memoir has been edited by Dr. Home. J. J. H. TEALL, Director. Geological Survey Office, 28 Jermyn Street, London, 30th September 1906. PREFACE TO SECOND EDITION The first edition of this Memoir was exhausted in 1911 and it became necessary to make arrangements for the preparation of a new edition. On account of the death of Mr. James S. Grant Wilson in 1908 the description of the Geology of the Oil-shale Fields was entrusted to Mr. K. G. Carruthers. Much boring and extensive mining develop- ments had gone on since 1906. and a large amount of new information has been collected. Many changes have accordingly been made in this part of the volume, in the horizontal sections across the shale- fields, and also in the map and table of vertical sections. A new colour-printed edition of Sheet 32 of the one-inch Geological Map of Scotland (Midlothian and part of West Lothian) was issued in 1910, but it is no longer strictly in accordance with Mr. Carruthers's views on the structure of certain parts of the shale-fields, and the principal corrections are indicated on the small-scale map that appears as Plate III. of this Memoir. New editions of the six-inch geological maps Linlithgow 9 S.E., 9 N.E., and 10 N.W. are being prepared for issue, as these sheets required revision. Mr. Caldwell and ]\Ir. Steuart have added such information as was necessary to make their contributions a satisfactory representa- tion of current practice in the mining of the oil-shales, their chemistry and the processes of manufacture. J. J. H. TEALL, Director. Geological Survey Office, 28 Jermyn Street, London, 3rd August 1912. CONTENTS. PART I. THE GEOLOGY OF THE OIL-SHALE FIELDS OF SCOTLAND By R. G. Caerfthers Introduction. .... I. Geological Position of the Shale-Measures II. Topographical Distribution of the Oil-Shales III. Physical Characters of Oil-Shale IV. Distinctive Geological Zones V. General Geological Structure i. The Main Faults ii. The Main Flexixres iii. Igneous Rocks VI. Detailed description of the Shale-fields i. Cobbinshaw . ii. West Calder . iii. Alderston, etc. iv. Polbeth and Gavieside V. Breich vi. Cousland and Seafield vii. Livingston and Deans viii. Mid-Calder ix. Pumpherston X. Broxburn xi. Winchburgh and Humble xii. Ecclesmachan xiii. Champfleurie and Philpstoun xiv. Duddingston XV. Queensferry and Dalmeny xvi. Ingliston and Newliston xvii. Dalmahoy xviii. Burntisland . xix. Inverkeithing XX. Burdiehouse and Straiton xxi. Carlops VII. A remarkable case of " Burning " in the Pumpherston Oil-Shales VIII. On the proving of Oil-Shale Strata .... PAGE 1 3 3 7 8 11 11 12 13 16 16 20 28 30 31 32 33 37 43 48 52 56 60 65 71 77 79 80 82 84 87 88 91 VI PART II. METHODS OF WORKING THE OIL-SHALES. By W. Caldwell. I. Search for Shale II. Mode of Access III. Mine Driving . IV. Level Driving . V. Blasting and Explosives VT. Methods of Working . VII. Timbering of Levels Vin. Gases and Ventilation . IX. Pumping Water X. Underground Haulage . XL Inclined Shaft Winding XII. Conveyance of Shale on Surface PART III. THE CHEMISTRY OF THE OIL-SHALES. By D. R. Steuart, F.I.C. I. Introductory and Historical II. Statistics ..... III. Minerals now or formerly used IV. Chemical Composition of the Valuable Shales i. The Crude Oil and Ammonia of Shales as the Laboratory . ii. Analyses of Crude Oils from various Shales iii. General Chemistry of the Shales V. The Process of Manufacture VI. Products of the Manufacture . i. Their Composition and Properties ii. Their uses .... determined m PAGE 95 97 99 ioi 105 108 118 119 127 128 133 134 136 138 141 143 143 155 157 170 189 189 192 LIST OF ILLUSTRATIONS. FIGURES IN TEXT. Fig. 1. General Vertical Section of the Carboniferous Strata of Mid and West Lothian .... 2. Section from Baads Mill across Cobbinshaw HiU 3. Section from Baads Mill to Limefield House 4. Section from Limefield Mains to Murieston 5. Section of Breich and Polbeth Shale-fields 6. Section across Deans and Livingston Shale-fields 7. Section across Mid-Calder and Newfarm Shale-fields 8. Section across the Calder and Murieston Faults through Oakbank Oil Works .... 9. Section across the northern part of the Pumpherston Shale-field 10. Section across the centre of the Pumpherston Shale-field 11. Section across the southern part of the Pumpherston Shale-field 12. Section across the northern part of the Broxburn Shale-field 13. Section across the southern part of the Broxburn Shale-field 14. Section from Midhope across the Winchburgh and Humbie District . . . 15. Section from Riccarton across the Ecclesmachan District . 16. Section of the Champfleurie Shale-field, south of Bridgend 17. Section from Pardovan past Philpstoun Oil Works, across the Gateside Ai'ch .... 18. Section across the Philpstoim Shale-field ... 19. Shore Section at Society and Queensferry ... 20. Section from Queensferry across the Dalmeny Shale-field 21. Plan of the Burntisland Shale-field ... 22. Section from GrangehiU to Common, Burntisland 23. Section of Burdiehouse and Straiton Shale-field . 24. (o) Represents a fold over ; (6) represents disturbed ground (c) represents Bore No. 2 having missed the shale 25. Trial Shaft, with a Level CVoss-cut 26. Mine driven in Oil-shale, at Pumpherston, with Level Cross-cutA 27. Mine driven in Folded Oil-shale Strata, Drumshoreland Basin 28. Vertical Shaft sunk in Oil -shales, Mid-Calder 29. Method of Timbering the Roof and Centre -propping in Muie driving ...... 30. Face of Level, showing the various kinds of Holes 5 17 21 29 30 34 38 38 43 45 46 49 49 53 57 60 60 61 68 72 80 81 84 96 97 97 97 100 102 31. Longitudinal Section through Holes .... 102 VIU Fig. 32. Plan of " Holers " . ., 33. Plan of " Brairders " „ 34. Electric DriU „ 35. Cleaner and Stemmer ,, 36. Cartridge in position in Shot-liole ,, 37. Stoop and Room Method of Working Oil-shale „ 38. Plan and Section of highly inclined Stoops „ 39. Creep of the Strata in highly inclined Mine „ 40. Method of Removing the Stoops . „ 41. Plan of Shale Mine worked on Longwall System . „ 42. Plan of Longwall Face .... „ 43. Section of the Fells Shale .... ,, 44. Method of Spragging Shale .... „ 45. Special Method of Working Oil-shale in Steps ,, 46. Section of Dunnet Shale, Oakbank Pit, Mid-Calder ,, 47. Longitudinal Section, showing Method of Working the Dunnet Shale, Mid-Calder ,, 48. Method of Working Vertical Seams of Shale „ 49. Roof supported by Ci-o\vn Tree ,, 50. Roof supported by Vertical Prop . „ 51. Roof supported by Steel Girder, supported by Vertical Props ,, 52. (a) Brick-arching ; (b) Brickwork and Girders „ 53. Fan used in Ventilating Shale Mines „ 54. (6) Brattice Boards ; (c) Brattice Cloth ; (p) Props „ 55. (a) Hand Fan ; {b, c, d) Wooden Rhones ,, 56. Method of fixing Rhones in Upset . ,, 57. Upset and Rhones in position ,, 58. Trap-door .... „ 59. Ventilation of Stoop and Room Workings „ 60. Cuddie Brae „ 61. Chain Pulley and Brake „ 62. Cut Chain Brae „ 63. Hook and Link ,, 64. Carriage for Self-acting Incl ,, 65. Plan and Elevation of Endless Rope Haulage „ 66. Hauling by Endless Rope from Liclined Shaft „ 67. Shale Breaker ,. 68. Horizontal Retort . „ 69. Old Vertical Retort „ 70. Young and Beilby Retort „ 71. Henderson Retort . „ 72. Bryson Retort ,, 73. Beilby Ammonia Column Still PAQB 102 IX F^G. 74. Henderson Ammonia Column Still. Two Trays 75. Henderson's Sweating Trays 76. Henderson's Cell Sweaters, Vertical Section 77. „ „ Plan . 78. „ „ Sections of a Cell 79. Henderson's >System of Recovery of Still Gases 80. „ „ (another view 81. Acid or Soda Washer, stirred with air 82. Connected Boiler Stills, with Residue Still 83. Heavy Oil Still .... PLATES. (At end of Volume. ) Plate I. Fossils from Scottish Oil-shale Strata. „ II. Comparative Vertical Sections of Scottish Oil -shale Fields. „ III. Geological Map of the Oil-shale Fields of the Lothians. PAGE 179 182 183 184 184 185 185 186 186 187 LIST OF PUBLISHED SIX-INCH GEOLOGICAL MAPS OF THE LOTHIAN SHALE-FIELDS. (Price One Shilling and Sixpence each, with geological lines, uncoloured. coloured maps can be obtained at cost of colouring.) Hand- LinUthgow 2 S.W., S.E. (Midhope, Duddingston and Queensferry). „ 3 S.W. (Queensferry and Dalmeny). 6N.W., N.E.. S.W., S.E. (Philpstoun, Champtieurie, Eccles- niachan. Broxburn and NeMliston). 7 N.W. (and 8.W.), (Dalmeny, South). „ 9 N.E., S.E. (Deans, Seafield, Bi'eich and Livingston). „ 10 N.W., S.W. (Pumpherston and Livingston). 12 N.E. (West Calder). Edinburgh 4 S.W. (North of Gilmerton). 5 N.E.. S.E. (Newfarm, Mid-Calder, NeAvpark, etc.) 7 N.E., S.E. (Straiton, etc.). 8 N.W. (Gilmerton). 11 N.W., S.W. (West Calder and Cobbmshaw). 12 S.E. (Carlops). 18 N.E. (Carlops). The following Maps of Oil-shale Districts are not published, but manuscript copies can be obtained if desired : — Linlithgow 5 N.E., S.E. (Riccarton, Bankhead, etc.). Edmbui-gh 2 S.W., S.E. (Ratho). „ 6 N.W., N.E. (Raw Camps and Dalmahoy). „ 11 N.E. (Murieston and Harburn). ,, 11 S.E. (Cobbinshaw and Tarbrax). 17 N.W., N.E. (Cobbinshaw and Tarbrax). Lanark 14 S.E. (Cobbinshaw and Tarbrax). 15 S.W. 20 N.E. 21 N.W. Fife 39 S.W., S.E. (Inverkeithmg, etc.). „ 43N.W.,N.E. INDEX LETTERS USED IN SECTIONS. In the horizontal and vertical sections, and coloured map (Plate III.), which accompany the detailed description of the Shale-fields the following abbrevia- tions have been employed : — T.L. Tartraven Limestone. C.L. . . . Cobbinshaw or Main Limestone B.B.I. . Black Band Ironstone. Mid. S. . Midhope Shale. R.S. Raebum Shale. M.S. Mungle Shale. 2F.C. . Two -foot Coal. Xll Abbreviations Pa. S. G.S. H.C. F.S. L. of F.S B.S. Ch. S. By. Sa. D.S. N.S. U.D.S. Bks. L. c.s. B.L. P.S. Q, Cem. Dal. S. C. O.S. Ls. Lsts. O.F. M.H.F. C.F. M.F. P.F. F. Paper Shale. Grey Shale. Houston Coal. Fells Shale. Limestone of Fells Shale. Broxburn Shale. Champflourie Shale. Binny Sandstone. Dunnet Shale. New Shale. Under Dunnet Shale. Barracks Limestone. Camps Shale. Burdiehouse Limestone. Pumpherston Shale, Queensferry Cement. Dalmahoj'^ Shale. Coal. Oil Shale. Limestone. Limestones. Ochiltree Fault. Middleton Hall Fault. Calder Fault. Murieston Fault. Pentland Fault. Fault. EXPLANATION OF PLATE I. (All figures natural size except where indicated.) Figs. 1 to 4. Marine Fossils from the Mungle Shell-Bed. Figs, 1, L*.. A Goniatite [fHyphioceras tnmcaium (Phill.)]. Usually found as flattened fragments of the terminal portion (see right hand of Fig. 1). Fig. 1a shows cross-section of whorl. Fig. 2. Marine Lamellibranch [SanguinolUes variabilis M'Coy]. Fig. 3, Marine Gasteropod [Ptyehomphalina aff. atomaria {T?hi\\.)]. Magnified 2 diameters. Fig. 4. Marine Gasteropod [Euphemus urei (Flem.)]. Figs. 5 to 8a. Marine Fossils from the Pumpherston position. Figs. 5, 6. Orthocerassp. Fig. 7. Marine Lamellibranch [Pseudamusium sp.]. Slightly magnified. Figs. 8, 8a. " Shrimp " \T ealliocaris sp.). Slightly magnified. Figs. 9 to 14b. Common Fossils of the Oil-shale Group. Fig. 9. Fern [Tdangium affine (L. and H.)]. Fig. 10. Fern [Bhacopteris lindsaeformis (Bunh.)]. Fig. 11. Estuarine Lamellibranch [^aiadi^es o6e«a (Eth.)]. Fig. 12. Brachiopod [Lingida squamifonnis Phill.]. Fig. 13. (jfdt,?,ieroT^odi9, [Platyoslomdla scotoburdigalensis (Eth.)]. Fig. 14. Entomostracan Limestone. Figs. 14a, 14b. Magnified figures of an Entomostracan [Leperditia sp.], 14a, side view, 14b, end view. PART I. THE GEOLOGY OF THE OH.-SHALE FIELDS. Introduction. The Scottish oil-shale industry is now mainly located in a belt of territory about six miles broad that stretches from Dalmeny and Abercorn, on the shores of the Firth of Forth, southwards across the fertile tract between the river Ahnond and the Bathgate Hills to the moorland district of Cobbinshaw and Tarbrax. Throughout this region there are various important mining centres, such as Broxburn, Uphall, East Calder, Mid-Calder, West Calder, and Addiewell, with large populations, mainly, if not wholly, dependent on this branch of economics for their support. The rapid development of this industry in the Lothians within the last forty years is strikingly exemplified by the fact that, when those portions of Midlothian and Linlithgowshire were first mapped by Sir Archibald Geikie on behalf of the Geological Survey in 1857, not one of the existing oil-shale fields in the Calciferous Sandstone Series was then being worked. The important discovery, which ultimately led to an active search for oil-shale, had been made, that oil could be obtained by distillation from the Torbanehill Mineral, a seam near the base of the Coal-measures in West Lothian. In the first edition of Sheet 32 of the one-inch map of Scotland, the outcrops of the Houston Coal and Burdiehouse Limestone, two important horizons in the Oil-Shale Group (Calciferous Sandstone Series) were indicated. While traversing that region Sir A. Geikie recorded on the six-inch maps various exposures of bituminous shales, whch we now know to be out- crops of oil-shales whose horizons are well defined. In the Memoir on " The Geology of the Neighbourhood of Edinburgh," pubhshed in 18G1, he referred to other prominent members of the same group, such as the Two-foot Coal, the Houston Marls, and the Binny Sandstone, all of which are of great stratigraphical significance in working out the structure of that region. From the map and memoir it is apparent that he fully reaUsed the extensive folding of the strata in West Lothian. The subsequent development of the oil-shale fields necessitated a resurvey of those areas in Midlothian and Linlithgowshire, which was successfully accomplished between 1884: and 1887 by Mr. H. M. Cadell, when attached to the staff of the Geological Survey. By the courtesy of many interested in that industry, a large amount of mining informa- tion was then placed at his disposal, which enabled him to trace the outcrops of the various bands of oil-shale and to determine the position of I 2 The Geology of the Oil-Shale Fields. the large faults affecting the structure of that region. The results of that resurvey were embodied in a second edition of Sheet 32, issued in 1892. In 1885, Mr. Cadell communicated a brief description of the'results of his re-examination of the shale-fields to the meeting of the British Association at Aberdeen in a paper entitled " Recent Advances in West Lothian Geology." He indicated the position of the various oil-shales then known in the course of mining operations, and furnished estimates of the thickness of the subdivisions of the Calciferous Sand- stone Series. Again, in 1901, he published a detailed account of the geologi^nl structure of the various fields in the Lothians and at Burnt- island \n Fife, accompanied by horizontal sections, in the Transdctions of the Institute of Mining Engineers, and also in the Transactions of the Edinburgh Geological Society. These materials, together with the notes based on the original survey, have been largely used in the preparation of the geological portion of this memoir. In the course of the revision of the Carboniferous areas of the Lothians by the Geological Survey, between 1902 and 1906, Mr. Wilson re- examined the oil-shale fields and obtained fm'ther information from the various mining managers and others interested in the industry. Among the more important results may be mentioned the more accurate deter- mination of the outcrops of the strata and lines of fault owing to the developments then reached in the Tarbrax, Cobbinshaw, Pumpherston and Breich fields, and the mapping of the new shale-field at Inghston. The revision led to the publication of the first edition of this memoir on " The Oil-Shales of the Lothians," which appeared in 1906, and to the issue of maps of the shale-fields on the scale of six inches to one mile. The demand for this memoir proved so great that the issue was rapidly exhausted, and a new edition became necessary, the preparation of which was begun early in 1911. As regards the geological portion, now presented, so much new information has been collected that it has been deemed advisable to practically rewrite the whole, with the exception of certain passages in the Introduction, and in the descrip- tions of the West Calder, Burntisland and Straiton fields. The new points of most general interest deal ^vith (1) the new areas now being worked at Livingston and Newfarm, and develop- ments in all the older fields, especially at Cobbinshaw, Ingliston, Philp- stoun and Duddingston, (2) the recognition of the Pumpherston Shales on the northern coast, and the revision of the Queensferry shore section, (3) the separation of the Barracks and Burdiehouse Limestones, (4) the recognition of the zonal value of certain horizons, especially two bands of marine fossils, which have been proved to extend over the whole field (the Mungle and Pumpherston Shell Beds), and also the Barracks volcanic ash, (5) the discussion as to the position of the Dal- mahoy Shale, (6) new outcrops of the Burdiehouse Limestone near Binny,Humbie and Kirkliston, (7) the demonstration that the teschenite sills are generally restricted to particular horizons, while the quartz- dolerite sheets are more irregular in their occurrence. Particular attention lias been paid throughout to the indication of fm'ther areas where oil-shale may reasonably l)e expected, a summary of the whole question being given in conclusion. Most of the horizontal sections have been re-drawn and some new ones inserted, while the plate of vertical sections, and the accompanying small scale map, have both been revised. Geological Position of the Shale-Measures. 3 i. Geological Position of the Shale-Measures. Tho sliale-measures on which the oil industry depends form part of the Calciferous Sandstone Series of Mid and West Lothian and the southern coast of Fife between Burntisland and Inverkeithing, the geological position of which will be readily grasped from the following tabular statement (see also Fig. 1, p. 5). The Carboniferous system in Scotland may be arranged in descend- ing order in four divisions as given below. 4. Coal - yneasures, comprising red sandstone, shales, and marls with no workable coals, underlaid by white and grey sandstones and shales with numerous valuable coal-seams and ironstones. 3. Millstone Grit, consisting of coarse sandstones with beds of fireclay, a few thin coals, ironstones, and thin limestones. 2. Carboniferous Limestone Series, embracing three subdivisions, the highest of which contains three or more limestones with thick beds of sandstone and some coals ; the middle includes valuable seams of coal and ironstone ; and the lowest is characterised by several beds of marine limestone, with sandstone, shales, some coals, and ironstones. 1. Calciferous Sandstone Series, forming two subdivisions. The upper, known as the Oil-Shale Group, is over 3000 feet in thickness, and contains, in its higher part, beds of coal usually of inferior quality, and farther down, about six main seams of oil-shale, interstratified with beds of sandstone, shale, fireclay, marl, and estuarine limestones. The lower or Cementstane Group, in which no oil-shales have yet been found, consists of white sandstones and shales, passing downwards into grey, green, and red shales, clays, marls, and sandstones, with bands of argillaceous limestone or cementstone. A well marked volcanic zone, that of the Arthur's Seat lavas, lies between these two divisions. In the accompanying vertical section (Fig. 1) the various sub- divisions of the Carboniferous system of Midlothian and Linlithgow- shire are represented, but it ought to be clearly borne in mind that, even within these limits, the rocks vary greatly in thickness from place to place. The sedimentation in the Oil-Shale Group is especially irregular, as the plate of vertical sections at the end of this volume indicates, but they contain many persistent beds which serve as stratigraphical constants. It may here be remarked that the whole Group is cleaj-ly of shallow- water origin, and was deposited over an area marked by intermittent subsidence of irregular amount, where incursions of the open sea were extremely rare. Much of the sediment must have accumulated under mud-flat conditions, for suncracks and " desiccation breccias " are commonly met with, especially in the marly strata that bulk so largely in the series. ii. Topographical Distribution of the Oil-Shales. Although the Calciferous Sandstone Series is well developed in other parts of Scotland, it has not hitherto yielded any oii-shale of economic importance beyond the limits of West Lothian, Midlothian 4 The Geology of the Oil-Shale Fields. and Fife. It is remarkable that though bands of this material are well developed along the western side of the Dalkeith basin, they either occur in an attenuated form or disappear on the east side of that syncline. Thin seams of oil-shale belonging to this series, occur on the shore sections north of Gullane and near Cockburnspath, in the counties of Haddington and Berwick, but not of sufficient importance to be worked with profit. Again, the shale-measures of West Lothian, which dip westward under the Bo'ness, Bathgate, and Wilsontown coal-fields and reappear some miles to the west without any oil-bearing shale, prove that, diu-ing a long interval in the Carboniferous period, the necessary physical conditions for the deposition of oil-shale of economic importance were confined to this limited area. Beginning first with the largest and most important areas in LinKthgowshire and the adjoining part of Midlothian we find that the western boundary of the shale-measures is marked by the base of the Carboniferous Limestone Series, which trends northward from the Cobbinshaw Reservoir to the Firth of Forth — a distance of about fifteen miles. Along their eastern margin, between Hailes and the mouth of the river Almond, there is no well defined limit, and the base of the productive shale-measm'es in that area is as yet largely con- jectural. In the following general account of the stratigrapliical sequence, the lowest beds are described first — a plan adopted, as far as possible, throughout this memoir. The opportunity is taken to deal at some length with the lower part of the series, which is of small economic importance, and is therefore not treated in detail elsewliere. Cementstone Group. — Since the discovery of fixsh remains of Upper Old Red Sandstone age, in the sandstones at Craigmillar and beneath Salisbury Crags, the base line of the Carboniferous system in the Edinburgh district has been drawn at the bottom of a group of grey, green and red mudstones, shales and cementstone bands, with occa- sional sandstones and rarely some thin seams of dark carbonaceous shale yielding plants. These sediments, which have a wide distribu- tion in Scottish Carboniferous areas and are typically represented at Ballagan north of Glasgow, are well developed in the old town of Edinburgh between the Castle and Holyrood Palace, in the Hunter's Bog east of Salisbury Crags, in certain stream sections on the north- west side of the Pentland Hills and in the Linhouse Water two miles south of Mid-Calder. The representatives of this group pass under- neath an important series of volcanic rocks — lavas, tuffs, and ag- glomerates — which appear on Arthur's Seat, the Calton Hill, and at Craiglockhart. Far to the south-west they occur in their normal position, on Corston Hill and in the Linhouse Water south of Mid- Calder ; and still further south on Black Hill and Torweaving Hill east of Cobbinshaw reservoir. Oil-Shale Grou/p. — Within the city of Edinburgh the volcanic rocks of Arthur's Seat and Calton Hill are surmounted by the Abbey- hill Shales ; these strata contain a few bands of variegated clays of Cementstone type, but for the most part they consist of dark blue shales or " blaes " often crowded with entomostraca. To the south- west, in the stream sections between Mid-C*alder and Harbm-n, thick beds of blaes are again seen resting on the lavas, and they are of pro- nounced Oil-Shale type, with thin ribs of entomostracan limestone and FEET 9000 III III I" III iiiutiiiim ^A^VVy.-) ^^ JKZ Red Sandstones Horizon not proved ' Dalkeith " and Musselburgh Coalfield Roslin Sandstone Coal " Levenseat " Limestone Coals '•Calniy" or Gair Limestone J Wood Extra Limestone -' Xld =^ ^■c 3^09 •y\P public road which leads from the railway station to Bellsquarry. On the west side of this fold the limestone is either at a high angle or in some cases is slightly inverted, while to the south-east of Bells- quarry it " forms a sharp synclinal fold on the north limb of which the beds are quite vertical and even a little inverted at Brucefield quarry" (Cadell, Trans. Ed. Geol. Soc, vol. viii., p. 142; Trans. Inst. Min. Eng., vol. xxii., p. 345). These quarries are now partly filled ap, and this basin is separated by the Calder Fault from the other two depressions which lie on the south side of the railway. The section line (Fig. 4) has been drawn across the largest of these folds as far as the Murieston Fault. Here the limestone was origin- ally worked open-cast, but it is now won by a shaft, 37 fathoms deep, near the centre of the basin. The stone, which is very pure, varies in thickness from 20 to 26 feet, and is used entirely for smelting purposes by Messrs. Baird & Co., Gartsherrie. Underneath the limestone is a seam of fireclay, but the " Buckie fake," which lies near the bottom of this fireclay at Camps quarry, has not been found in this working. This basin has nearly vertical sides, and the excavations show that its bottom consists of a succession of smaller undulations. The southern portion of this field is in- tersected by the Murieston Fault, and here the Burdiehouse Limestone is let down against the upper part of the volcanic rocks of Corston Hill, which is equal to a displacement of at least 300 fathoms. A branch of this dis- location runs in a north and south direction on the west side of Dressel- rig, the downthrow being to the west. Pumpherston Shales. — Young's Oil Company are now working the Jubilee Shale of the Pumpherston Series in a mine driven 600 yards south of Alder- stone, the shale cropping out in an anticlinal fold, of which the western limb has been proved by boring. North of Brotherton a bore started on the crop of the Burdiehouse Limestone, and proved the shales 86 fathoms below. Further boring found the shale crop p*assing through Brotherton : to the north-west of Bell's quarry the strata are much disturbed, and are sharply folded, while there is at least one large fault, with a downthrow to the north. There is every probability that the Shales exist under the small NO 1103 s f- 30 The Geology of the Oil- Shale Fields. troughs of the Burdiehouse Limestone round Newpark, and they probably outcrop on the west side of a line drawn between Westfield and Wester Murieston. Sections visible 200 yards west of Westfield show shaly blaes and shale with greenish marly sandstones, the strata being greatly disturbed and dipping in contrary directions. A recent shallow bore, to the south-west of Wester Murieston, also proved several thick beds of inferior shale at the surface, inclined at a high angle. It is quite possible that a valuable field of Pumpherston Shales could be got hereabouts, and in addition the lower shale, lying under the Pumpherston Shell Bed, may also be present (see p. 35, etc.) 4. Polbeth and Gavieside Shale-field. {Linlithgow, 9 S.E. and 12 N.E.) The Polbeth Shale-field is an easterly continuation of the Breich area. The strata lie in a deep basin, which is an extension of that found to the north of West Calder. The lowest beds exposed on the east side of this fold immediately underlie the Dunnet\Shale, while in Fig. 5. — Section of Breich and Polbeth Shale-fields. the centre of the trough strata above the Raeburn Shale are reached. (See Fig. 5.) In the Hartwood Water, north of the Brotherton Fault, there is a good section of the beds beneath the Dunnet Shale, consisting of green sandy blaes with green and grey sandstones. The Shale is being mined by Young's Company, the workings extending to the bottom of the trough, where they are at a vertical depth of 250 fathoms from the surface, this being the deepest mine in the Scottish shale-fields. Since the bottom of these workings terminate against the Langside- Blackburn Fault, which is known to have a downthrow south of 200 fathoms, they should be brought by this displacement against the Pumpherston Shales, which could be proved by a mine driven througli the Fault. The Fault is again seen by the stream south of Langside, where there is an excellent section of the Under Dunnet Shale. In the floor of the seam there is an inch of volcanic ash (Barracks), and below are sandstones, the limy top of which represents the Barracks Limestone position. The Langside-Blackburn Fault, which marks the northern boundary of the field, has been proved in the Dunnet workings south and west of Langside ; the Two-foot Coal is seen nearly vertical, where this fault crosses the Breich Water, south of Grange. Gavieside Field — Breich Shale- field. 31 Gavieside Field. On the north side of the Langside-Blackburn Fault, between Gavieside and the river Almond, there is a broad basin containing the Dunnet Shales. This trough is a northerly continuation of that at Polbeth, and the Langside Fault has a displacement at this point of 200 fathoms. At the Gavieside mine the Main Dunnet varies from 6 to 16 feet, but its general worldng thickness is 10 feet. A section here gives — Feet Roof, Shale 6 Top Shale, plain . 4 „ curly . 2 „ plain . 1 Bottom Shale 3 16 At the north end of the Gavieside syncline, several outcrops of dolerite are seen in the river Almond between the weir and the ford west of Livingston, where the Lower Dunnet Shale is seen by the stream, with the Barracks Ash and Limestone (at least 1 ft.) below, while the Main Dunnet seam was proved several years ago by trial pits. To the east of this weir marly strata, together with conglomerate bands and limy ribs of sandstone, are exposed along the north bank of the stream. North of Grange there is probably a fault, down north, and coming from the direction of Alderston, which separates this area from the Gavieside field to the south. 5. Breich Shale-field. {Mostly in Linlithgow, 9 S.E. ; the southern fart in Linlithgow, 12 N.E.) This field reaches from the Langside-Blackburn Fault southwards to Mid-Breich, where it is separated from the West Calder area by a fault running east and west, down south 10 to 20 fathoms. Until recently, the structure of the ground was obscure, as consider- able folding occurs. Extensive boring operations have been done by the Pumpherston Company, who are now opening up part of the field. Some boring has also been done quite lately by the Oakbank Company near Easter Breich. The main axis of the Dechmont Arch passes southwards through the field (see Fig. 5), and on the east side minor folds appear trending in a similar general direction. The core of the chief anticline, east of Blackburn House, is occupied by the Dunnet Sandstone Group, and as the fold pitches to the south, successive outcrops of the overlying shales appear. On the west side of the arch, south and south-east of Blackburn House, the strata are at first very steep, and trial pits and borings found the Dunnet Shale almost vertical. The inclination of the seams lessens towards the west, the Broxburn Shale lying at 60° and the Fells Shale at 40°, but it persists steadily, so that the Cobbin- shaw Limestone and Coal are reached within half a mile, at the east end of Blackburn village. Little is known of the strata above the 32 The Geology of the Oil-Shale Fields. Fells Shale, although there are several old shafts to the Houston Coal, and near Hopefield Mills there was a day level to the Two-foot Coal. On the south-east side of the main anticline there is a trough containing the Broxburn and Dunnet Shales, to which pits have just been sunk by the Pumpherston Company. Borings hereabouts indicate that the strata rise gently towards the south up to an arch in the Fells Shale at Hermand Oil Works, where both Fells and Brox- burn Shales were worked out some time ago. Little is definitely known as to the structure of the east side of the field near Easter Breich ; probably there are two sharp folds trending south-west, and separated by faulting, and bringing up the Fells and Broxburn Shales to the surface (see Fig. 5). Beyond this troubled belt the strata dip steadily into the Polbeth Basin. There are few natural exposures in the Breich field, but diamond bores have afforded good sections of the strata between the Fells and Dunnet Shales. The general development is much the same as in the Deans field, though the Fells Shale is much thicker ; this seam has been extensively wrought between Easter Breich and the southern boundary fault. The group of Dunnet Shales lie in some 20 fathoms of strata, mostly blaes ; in the middle is the Main Dunnet Shale, 12 to 14 feet thick, with one or two partings of limy cementstone an inch or so thick. The Upper and Lower Dunnet Shales are poor and irregular. The overlying Binny Sandstone Series, about 40 fathoms thick, has several beds of green marl in the upper part, the sandstones being poor ; lower down there is a good deal of grey marl, and there are bands of thin bedded limy sandstones with brown ribs just above the Dunnet seams. The Broxburn Shales are well developed, four seams, all close together, having been proved ; one of them was 4 feet 4 inches thick, but they vary considerably and appear to thin towards the north- east. The Broxburn Marls are about 30 fathoms thick, several lime- stone bands occurring as usual at the top of the series, under the Fells Shale. A section of the latter seam is appended below. Section of Fells Shale at Easter Breich. Roof, blaes. Shale, plain „ curly ,, plain BaU ply . Shale, inferior Holing, blaes. 4 9 6. Cousland and Seafield Shale-fields. {Linlithgow, 9 S.E.) These fields lie between the Deans and Breich areas ; they are bounded to the south by the Langside-Blackburn Fault, down south about 60 fathoms. Feet. Inch 8 1 2 1 11 6 6 Cousland and Seafield Shale- fields. 33 The area is bisected by the Middleton Hall Fault, which has a downthrow to the north of 80 fathoms at Barracks, but increases rapidly towards the south-west, being some 150 fathoms at Seafield ; most of the mined area lies north of this fault. The current maps represent this fault inaccurately. The chief seams worked belong to the Dunnet Shales, and the general sequence is in agreement with that in the Deans field. The Broxburn suite of shales are considerably thicker, however, and they lie only 20 fathoms or so above the Main Dunnet Shale. West of Cousland there is a small trough Vvdth the Houston Coal in the centre, and the Fells, Broxburn and Dannct Shales on the east side. On the west side of this fold a reversal of the dip repeats the outcrop of the Houston Coal, which is succeeded by the Two-foot Coal and the Raeburn Shale. These beds incline to the west, and pass under the Cobbinshaw Limestone to the north-east of Blackburn village. At Seafield Oil Works there is a sharp anticline in the Fells Shale. In the nortli-wcot part of the field a small opening was made long ago in the Raeburn, or Dam Shale, south of Stailaw, a'ul there are several old pits to the Housto]\ Coal. South of the Middleton Hall Fault much of the ground is obscure. As yet only the west side of this area is definitely known ; here the Dunnet and Broxburn Shales are worked, dipping v/est at 22°. Recent boring found the Fells Shale only 12 fathoms above the Broxburn. Otherwise the sequence agrees with Deans, the Dunnet Shales being fully developed ; one bore passed through the Barracks Limestone, 6J feet thick, and then through nearly 42 fathoms of sandstone strata beneath (Dunnet Sandstone Group). East of Seafield there must be a broad anticline, for near Grange the Dunnet Shale is found dipping east into the Gavieside Trough. This anticline is really part of the long Dechmont Ridge, and is Avell seen in the Breich field to the south. It can hardly l)e a simple arch, judging both by the sharp folding of slialy blaes seen in the river Almond, about ^ of a mile above its junction with the Breich Y\'ater, and by the abrupt folding north of Seafield Oil Works. Most of this ground between Seafield and the river is probably occu- pied by the Dunnet Sandstone Group, in continuation v/ith that round Long Livingston. A valuable field of Pumpherston Shales probably exists here, at quite workable depths, to judge by the per- sistent westerly thinning ot the strata under the Burdieliouse Lime- stone which is exhibited in the Livingston field ; owing to the steep dip at the junction of the Breich and Almond, they may even out- crop south of Cousland. A greatly decomposed igneous rock is seen in the Deans Burn south of Cousland, possibly belonging to a neck, but its field relations are very obscure. 7. Livingston and Deans Shale-fields. {Linlithgow, 9 N.E., S.E. and 10 N.W., S.W.) These fields lie to the north and west of Livingston village. The recent geological revision has led to an important modification in the sequence of strata in the district : the Barracks Shale and Lime- stone, wliich hitherto have been identified with the Camps Shale and 3 34 The Geology of the Oil-Shale Fields. Burdiehouse Limestone, are now proved to lie some 120 fathoms above the latter. In addition, some invaluable evidence as to the characteristics of the strata associated with the Pumpherston Shales has been given by borings put down by the Pumpherston Company in the Livingston field. t-wjcuAs us. Fig. 6. — Section across Deans and Livingston Sliale-fields. The two fields are separated by the Middleton Hall Fault, trending S.W., and having a downthrow to the north-west of 80 fathoms or more ; this fault runs approximately down the centre of a strong anticline (the Dechmont Arch), and on the west side of the disloca- tion, in the Deans field, the outcropping strata range from the Dunnet group of shales up to the Raeburn position. On the east side of the fault much lower strata appear, from the Pumpherston Shales up to the Dunnet, and these occupy the Livingston lield. The existence of the Pumpherston Shales here is a new discovery made by the Pumpherston Company, who are now opening up the area. Ex- cellent sections of the strata in this district are seen in tlie stream flowing from Dechmont southwards to the river Almond at Living- ston, the beds dipping in a general south-easterly direction. Livingston Shale-field. Pumpherston Shales. — These Seams outcrop in a sharp anticline to the north -east of Livingston railway station, where they are visible in tv/o small quarries. The Shales are badly weathered, and contain several ribs of limy cementstone. The series of borings which have recently proved the Pumpherston Shales in the Livingston field extend from Nether Dechmont south- wards and west beyond East Long Livingston. The sequence found agrees remarkably well with that at Pumpherston, except that the Siiales lie much closer to the Burdiehouse Limestone, a ra])id thinning of the intervening strata taking place towards the west (120 fathoms at Pumplierston, 89 fathoms at Newyearfield, 45 fathoms south of Tailend). Work has just begun in the new field by way of a mine driven south- v»^ards from the Dunnet Shale pit at Barracks through the Middleton Hall Fault. A bore put down in tlie northern part of the area, at Nether Dech- mont, found the Shales destroyed by thin intrusions of dolerite. A further bore, put down north of Newyearfield, also found the Shales useless, their position being represented by strong dark blaes. This boring was continued -lO fathoms below the shale position, in an endoavovu' to prove the " whin " which had presumably spoilt the shale. An examination of the cores gave results of unusual interest. Previ- Livingston Shale- field. 35 ously no good index to the Pumplierston position wfis known which could be expected to have more than a purely local value, for the strata above these Shales up to the Burdiehouse Limestone are re- markably featureless in character, while little was known of the beds "below. The Newyearfield bore showed that the Pumpherston Shales are underlain by ribs of volcanic ash, covering a soft pyritous blaes crammed Avith marine shells {Orthoceras, Goniatites, &c.). This shell bed probably extends all over the Lothians, and it has already been identified at Hopetoun and Queensferry, and in a modified form near Burntisland, and at Carlops, in Midlothian. With one exception (p. 93, footnote) no fossil bands of this nature are found in the overlying strata until the Mungle Shale is reached. Under the shell bed, dark blaes occurred with abundant remains of Tealliocaris, a shrimp-like form, but these striking little fossils are probably quite local. The bore also gave evidence that there is a new oil-shale position close under the shell bed, and this seam has also been proved to the south, in the Oakbank Company's bores near Dedridge quarry (see p. 39.) All the strata, from the Pumpherston position downwards, gave of! a strong smell of petroleum when scraped with a knife, oil- shale positions being represented by strong dark blaes, with a deep brown streak. Curiously enough, no dolerite was met with at any point in the boring, nor were any of the plant remains carbonised. A reason for the destruction of the shales is suggested farther on. A condensed summary of the journal is appended (p. 88). BORE AT NEWYEARFIELD, NEAR LIVINGSTON. fmc. ft. ins. Grey and white sandstone in beds, some coarse, and bands of grey marly blaes with some shaly blaes near the base Yellow sandstone rib (ashy) ...... Banded pale blue and grey Limestone -with glassy fracture (Burdiehouse) . . . . . . Grey fakes and marly blaes, and sandstone beds, some coarse Blaes and shaly blaes ...... Dark blaes with a few thin ribs of white marly sandstone . Grey limy cement rib ...... Blaes with occasional plant fragments and thin ribs of limy cement Grey limy cement ....... Strong dark blaes, with dark streak, and partings of lighter blaes with ribs and balls of cement (Pumpherston Shale Position) . Dark blaes with good fern impressions .... Blaes with thin ribs of brown sandstone .... Blaes Mith bands of sandstone and hard white and grey marl with stripes of coarse volcanic ash . . . . .900 Pyritous grey blaes with, abundant remains of marine shells {Orlhoceras, Goniatites, small lamelhbranchs and entomos- traca) (Pumpherston Shell Bed) .... Blaes with ribs of brown sandstone ..... Strong dark blaes -wath abundant shrimp remains Strong dark blaes, with dark streak, and bands of limy cement (oil-shale position) ....... Dark blaes -ttith fish remains and occasional small f-hrimps Hard kingle sandstone, limy ...... Burdiehouse Limestone. — Old workings in this limestone can be seen crossing the stream half a mile east of Livingston railway station. 71 2 9 4 46 2 o 12 o 1 14 G 8 3 3 9 3 4 9 2 1 - () 3 12 8 36 The Geology of the Oil-Shale Fields. and tliey extend northwards towards Dechmont in a chain of aimn- doned quarries. The stone is of the usual pale weathering blue-and- grey type, with a glassy fracture, but all over the district is banded and well laminated throughout, without the massive cherty beds also seen in the Mid-Calder region : it varies from 5 to 15 feet in thickness. A few inches of yellow ashy sandstone are commonly seen resting on the limestone, but the overlying Camps Shale is poorly represented by shaly blaes Avith partings of sandstone and thin limy ribs. A trial pit to this Shale was sunk many years ago to the west of Knightsridge, but was soon abandoned, owing, it is said, to the heavy flows of water met with. The succeeding strata, belonging to the Dunnet Sandstone Scries, are probably not less than 120 fathoms thick. They are well exposed in the Livingston burn, a more or less continuous section being visible ; the strata consist mostly of soft brownish sandstone, mth bands of fine conglomerate composed of quartz, red and greenfelsite and cement- stone pellets, up to half an inch in diameter. In the lower part of the series there are several beds of slialy blaes, while near the top is a band of limy kingle sandstone, with small oolitic grains. Barracks Limestone and Dunnet Shales. — Overlying the sandstones in the above stream section, the Barracks Limestone can be seen, at least two feet thick, about 230 yards above the main road itito Living- ston. This bed, as in the Craigs diamond bore and in the disused Barracks quarry, is here a dark freshwater limestone not unlike the Burdiehouse, but with a rougher fracture ; ' suture structure ' along the bedding planes gives a pitted appearance to the stone. Above the road bridge there are traces of old trial shafts, perhaps sunk in search of the Houston Coal, the blaes being very dark here- abouts. The Dunnet Shales are not exposed, but they probably under- lie Livingston \'illage as far as the river Almond. There is no reason to suspect the presence of the Houston Wood dolerite sill, which has destroyed such large areas of Dunnet Shale to the north-east. In fact, the lowest or Under Dunnet Shale seems already to have been proved, for it is practically certain that this is the shale found in a bore at Livingston Offices, a quarter of a mile north of the village. The section was — BORE AT LIVINGSTON OFFICES. Feet. Inches. (Under Dunnet) Shale .... 3 6 Blaes ...... 3 (Barracks) Limestone . . . . .50 Deans Shale-field. The Dunnet Shales form the mainstay of this well-known field ; they curve round the southern end of the Dechmont anticline, on the west side of which they have been worked for many years. On the east'side of the arch, between Barracks and Tailend, these Seams lie in a small trough, cut of? to the south-east by the Middleton Hall Fault (see Fig. 6.) This is the original locality where the Barracks Limestone was quarried in past times, together with its overlying oil-shale (Under Dunnet) ; the Main and Upper Dunnet Shales Deans Shale-field. 37 have lately been discovered in this small infold, and are now being worked. Several diamond bores have been put down within the last few years by the Pumpherston Company, proving strata up to the Two-foot Coal position. Dunnet Shales. — The Barracks Limestone (formerly regarded by the Geological Survey as the Burdiehouse Limestone) lies at the base of this valuable group of shales. Fragments scattered about in the old quarry west of Barracks Farm show that it is a dark grey freshwater limestone of good quality, with a rough fracture ; bores in the vicinity show that it varies from 6 to 8 feet in thickness. The overlying shale {Under Dunnet ov Barracks) rests almost directly on the limestone; it is variable in quality, and is not wrought to any extent. Bores record 3 to G fathoms of fakey blaes and fireclay above this seam, succeeded by the Main Dunnet Shale, the latter from 10 to 14 feet thick, of excellent quality. A higher seam, known as the Upper Dunnet, is partially mined, but varies considerably ; it is separated from the main shale by about 6 fathoms of blaes, and occasionally attains a thickness of G feet or more. Above the Dunnet Shales, the Binny Sandstone Series is repre- sented by some 35 fathoms of strata ; in the lower half of this group the Dunnet Marls, with ribs of brown kingle sandstone and limy cement, are well developed, but in the upper part, in the position of the Binny Sandstone proper, there seem to be no well-marked freestone beds, and the strata are faky and irregular. The Broxburn Shale group is not more than 5 fathoms thick. Several beds of shale and shaly blaes occur here, but only one seam is being worked at present. The overlying Broxburn Marls show great variation in this field. In one bore, close to Starlaw School, they were 21 fathoms thick, but in two bores, situated about 200 yards further south, this was reduced to 10 fathoms. In the middle of the marls is a bed of coarse conglomeratic sandstone, while several beds of limestone are recorded in the upper part, close under the Fells Shale. The latter seam is thin, and is not worked at present ; it is separated from the overlying Houstoti Goal by 20 to 27 fathoms of fakes and sandstone. Several disused pits to this coal (which has a maximum thickness of G feet) have been sunk in the northern part of the field ; the Grey Shale, a few feet above, is very thin. The green and grey Houston Marls are about 2G fathoms thick ; the Two-foot Coal above has been proved in a diamond bore south of Starlaw School, but was only eighteen inches thick. 8. Mid-Calder District. {Edinburgh, 5 N.E., S.E. and *G N.W.) The area under description lies between the river Almond and Murieston Fault, and extends from Crofthead in the west to Raw Camps quarries in the east — a distance of four miles. The ground ie bisected by the Calder Fault, south of which the productive shale- measures do not extend, the elongated strip between the Calder and Murieston Faults being occupied by strata far below the Pumpherston Shales, and even by part of tlie Cementstone Group (Fig. 8.) * Geological map not published, but supplied on special order. 38 The Geology of the Oil-Shale Fields. tc5 3synoo 7j/f j7 asunoo 13A31 .''J 3yoa 3- lid Si. ^ o 3 O O 00 6 (-) FN Mid-Colder District. 39 The structure of the shale-bearing area north of the Calder Fault is in continuation with the Pumpherston field further north. In the centre, west of Mid-Calder, there is a low anticline bringing up the Dunnet Sandstone Series, and on either side of this fold synclines are found, containing many valuable shale seams (see Fig. 7.) The Mid-Calder Trough, lying on the east side of the arch, has long been known, and is now worked out. It contains all three of the Dunnet Shales, together with a full development of the Broxburn Shales. The westerly syncline, near Newfarm, is the deeper of the two. It had always been supposed to be shallow, with the Houston Wood dolerite, at the Dunnet position, in the centre. Within the last few years, however, boring operations by the Oakbank Company proved that the trough is a deep one, containing not only the Broxburn and Fells Shales, but in addition the Houston Coal and Marls. The new field has now been opened up, electric haulage being used ; a pioneer feature is the introduction of an aerial ropeway, also with electric power, to convey the shale from the mines to the refinery, a mile and a half away. The Newfarm Basin is cut off to the south by a branch of the Calder Fault, throwing up the Pumpherston Shales approximately against the Broxburn — a displacement of 250 fathoms. Burdiehouse Limestone and Pumpherston Shales. — Near Crofthead, in the western part of the area, there is an old abandoned working (the Dedridge quarry) in the Burdiehouse Limestone. Fragments of the limestone can be picked up which show that it is of the usual type, banded and grey in colour. Resting on the limestone is a thin rib of yellow sandstone, above which the Cam-ps Shale, greatly weathered, can be seen, about 3 feet 6 inches thick. A diamond bore at this quarry, by the Oakbank Company, proved the Pumpherston Shales 85 fathoms below, and a further boring to the south found another shale position 25 fathoms below. Betv/een these two hoiizoi^s is the position of the marine shell bed noticed in the Newyearfield boring, near Livingston (see p. 35.) In the Mid-Calder Basin, to the east, the following table gives the section of the strata proved by the mining operations of the Oakbank Oil Company at Mid-Calder and by a bore sunk by that Company, in 1892, from the bottom of their pit shaft to the Burdiehouse Lime- stone. It will be seen that the latter horizon was reached at a depth of 56-i feet below the New Shale. SECTION OF OAKBANK PIT AND BORE, MID-CALDER. Description of Strata. Broxburn Marls . Wee Shale Strata, blaes and lime ribs Bio Shale Strata Lower Big Shale Strata, shaly blaes Curly Shale Strata, blaes Thickness Depth from of Strata. Surface. Ft. ins. Ft. Ins. 46 46 0^ 1 47 6 13 60 6 4 () 65 o 12 77 6 S3 4J 10 93 2 G 99 3 5 104 40 The Geolofjj/ of the Oil-Shale Fields. Desciii>tion of Strata. Bkoxbtjrn or M'Lean ShnJe Stnita, chiefly bl-ies Wild Shale Strata, blaes, Binny Sandstones anJ mai DuNNET Sha.'e Strata, marly blaes New Shale, botto;n of shaft Strata, blaes Sha!e .... Strata, blaes and shale, with ribs Under Dtjnnet Shale, with fireclay rib Strata, blaes and hard ribs Sandstone ^'ery hard white whinstoue or kingle Hard faky sandstone Barracks Limestone, hard Sandstone, very hard, with hard blaes Conglomerate, fine Sandstone, faky blaes and liard ribs BuRDiEHOUjE Limestone Fakes and sandstone Thickness l)e2)lh from • of Strata. Surface. Ft. Ins. Ft. Ins. 4 108 01 k; 124 3 4 128 o "iV beds . 28S 410 G 422 4J et-1 4r> 407 2 8 475 O; 05 n 540 9 2 542 9 22 504 9 i in. thick G :j 571 f) 1 570 1

R. ALMOND Fig. 10. — Section across the centre of tlie Pumpherston Shale-field. able that shale beds of some kind were passed through, which had been burnt out by the intrusive rock. The Pumpherston Shales have recently been found in excellent condition on the west side of the field, near Livingston (see p. 34.) There is no reason to doubt that they extend in full force between Livingston and Pumpherston, although in the deepest part of the trough, below the Houston AVood dolerite, they must lie at least 250 fathoms below the surface. On the east side of the main anticline, the shales have been proved in deep bores by the Broxburn Company round Drumshoreland. Further borings by the same company near Illieston indicate that the seams have been destroyed by igneous intrusions, as may be seen at the outcrop along the River Almond to the east. They have not yet been proved under the Raw Camps limestone quarries, nor round Almondell or Clapperton Hall. There is a sharp anticlinal fold in the river at Almondell, which brings up to the surface some beds of shaly blaes with thin limestone ribs that are found all over the district about 40 fathoms above the Pumpherston position. Consequently, a bore here would prove the shales within 50 fathoms, 4G The Geology of the Oil-Shale Fields. ^^: 96oN3»0a PL, P^ without any trouble from the heavy surface deposits which cover the ground to the north, filUng in the pre-glacial river channel. The Al- mondell arch probably extends in a more or less modified form as far north as Illieston, perhaps even to Kilpunt, bringing the Shales near the surface along its course (see Fig. 10). The strata between the Pum- pherston Shales and the Burdiehouse Limestone have been proved in diamond bores on each side of the main anticline, both at Pumpherston and Drumshoreland. In the latter case the cores were examined by the Geological Survey a few years ago. As in the Livingston borings, the strata presented a monotonous suc- cession of sandstones, with hard limy bands, fakes and blaes, with scattered fern debris and occasional entomos- traca, while beds of fine conglomorat^ appeared in the upper portion. Not a single bed was noticed with any well marked peculiarity ; the most con- stant feature is perhaps the stratum of shaly blaes that occurs about two-thirds down from the limestone, Vv^hile there was always a thick bed of blaes with hard cem^ent ribs im- mediately above the Shales. Burdiehouse Limestone. — The Bur- diehouse Limestone has frequently been proved in bores in the Pumpher- ston field, but is not exposed in any surface section. It is very strongly developed on the east side of the main anticline. In a deep boring near Drumshoreland station, the limestone was 22 feet thick, cream coloured, andj with strings of chert near the base, as in the river at East Calder. The lower part was lumpy, the upper, grey and banded, and the stone had a glassy fracture through- out, and contained abundant ento- mostraca and plant debris. In another boring, near Clapperton Hall, the limestone was no less than 53 feet thick, and making allowance for the dip, reported to be 23°, this would mean a true thickness of Pumpherston Shale-field. 47 48 feet at this point, which is more than in any other part of the Lothians. The stone is less massive on the west side of the Pumpherston arch, where it has an average thickness of 15 feet, and is apparently all of the grey banded type, as in the Craigs diamond bore and in the Livingston field. In two deep bores near Pumpherston, at Milkhouses and Houston Wood, it is recorded as " blaes and limestone." At the north end of the arch, near Ryal, the limestone has been proved, and again to the south, and doubtless it outcrops completely round the fold. Resting immediately on the limestone, one or more thin ribs of yellow sandstone are commonly found, and above this 10 to 20 fathoms of blaes, all more or less shaly, but especially so at the top and bottom of the blaes. The lower seam is known as the Camps Shale. Camps Shale. — This Shale (hitherto erroneously identified with the Barracks Shale) is workable on the v\rest side of the Pumpherston arch, where it is at present being wrought by the Pumpherston Com- pany at No. 4 mine. The seam is here 7 feet thick, with a fireclay pavement and shale roof, the quality varying from good to medium. 0]i the east side of the anticline the seam deteriorates, and has usually been recorded in bores as " shaly blaes " (Kilpunt and Drum- shoreland). Round the soutli end of the arch it apparently disappears altogether, and its position is occupied by " blaes and ribs." Dunnet Sandstone Group. — On the east side of the Pumpherston anticline about 70 fathoms of strata intervene between the Camps and the Under Dunnet Shales ; westwards, towards Knightsridge and Livingston, they thicken out to 120 fathoms. These strata are not exposed at the surface, although they are quite typically seen in neighbouring districts at Livingston and Mid-Calder. In No. 2 diamond bore by the Oakbank Company at Craigs, south- east of Pumpherston, this series consisted mainly of sandstone beds, with partings of grey marl and marly blaes ; in the middle were bands of fine conglomerate with Kmy sandstone and cements, one of which was full of minute worm-tubes. A.t the top of the group was a bed of dark entomostracan limestone (the Barracks Lime- stone) 5 feet thick, in many respects like the Burdiehouse, but with a rough hackly fracture, as at Barracks and Livingston.* Above this was about 12 feet of conglomeratic sandstone, surmounted by 3 fathoms of soft greenish fclspathic ash, with chips of blaes and comminuted igneous material (Barracks Ash). Immediately above the ash was the thick bed of blaes, in which is the position of the three Dunnet Shales, here burnt out by the great whinstone "float" of Houston Wood. Similar strata were noticed in the deep bore near Dnimshoi-eland station, although here the Barracks Limestone had thinned down to a few inches only, as it does elsewhere on the east side of the Pumpherston arch, in the Mid-Calder field. Dunnet Shales. — The three seams of this group (Under, New and ■Main Dunnet) are fully developed on the east side of the Pumpherston anticline, where they are at present being worked in the Clapperton Hall Trough, by the Pumpherston Co., the Shales being vertical on * Going on, the bore proved the Burdieliouse Limestone, in quite typical development, 01 fathoiiis Ijelow, thus confinuing the evidence for the separation of these liraestor.e.s, which is provided in the Livingston stream section. 48 The Geology of the Oil-Shah Fields. the west side of the syncline. The Under Dunnet (or No. 3 seam) has been proved northwards up to the Middleton Hall Fault, in a narrow extension of the Clapperton Hall and Mid-Calder Trough. To the west all the seams are probably destroyed by dolerite. Broxburn Shales. — In the south-east corner of the field an increase in the depression of the Clapperton Hall Trough has let down a small area of the Broxburn Shales, now being worked (Fig. 11). The Shales obtain their maximum development in the Lothians at this point, and in one boring no less than GO feet of shale were found within a distance of 23 fathoms, the strata being gently inclined, and the intervening beds consisting of shaly blaes and blaes with hard limy rib.3. In this section the M'Lean, or Broxburn Shale proper, reached the extraordiaary thickness of 28 feet, although it should be men- tioned that subsequent mining proved this to be a " pocket." All the seams are of high quality, as they are in the southerly continuation of the trough at Oakbank and Mid-Calder. There is a remarkable development of marl round Clapperton Hall. The Binny and Dunnet Sandstone Groups, which are respectively 40 and 45 fathoms thick, liave, as a matter of fact, very little sandstone strata at all, being almost wholly composed of marl with hard ribs of limy cementstone at irregular intervals. In the centre of the basin, about 20 fathoms of Broxburn Marls have been proved in bores, the lower part being, as usual, greenish in colour. Another r^mall but valuable basin of the Broxburn Shales is now being worked by the Broxburn Company on the north-west side of the Pumpherston arch, near Loaninghill. The shales are not so thick as at Clapperton Hall, but three seams have been proved, each 5 to 6 feet thick, separated by blaes with limy ribs, the whole series occupying about 11 fathoms of strata. The Broxburn seam in par- ticular is of very fine quality. On the east side of the trough the shales dip down at 45°, and they are greatly contorted and overfolded, although still rich in oil. Bores show that there is a sill of dolerite in the Champfleurie or Lower Grey Shale position, 15 fathoms below the Broxburn. This " float " is well known in the Broxburn field, and should not be confounded with the great Houston Wood intrusion, which comes 70 fathoms or more, below, in the Dunnet position : the current one-inch map requires correction in this respect. There must be a fault between the out- crops of the Broxburn Shale and the Burdiehouse Limestone at this point, as they are only 400 yards apart, and normally there must be at least 180 fathoms of strata bsUveen these positions, to which the thickness, probably considerable, of the two whin sills must be added. At Loaninghill the Broxburn Marls are 23 fathoms thick ; at the top the Fells Shale has been proved, but it is too thin to work at the present time. 10. Broxburn District. {Linlithgow, 6S.W.,S.E.) This area includes the Broxburn and Uphall fields, and is bounded to the south by the great Middleton Hall Fault, and to the north by the Ecclesmachan aiid Niddry Castle dislocations. Broxburn District. 49 Tlie Broxburn Shales are here of very fine quality, and are prac- tically worked out, mining being now carried on in the Dunnet Shale, of which large areas yet remain. In the centre of the district lies the deep Middleton Hall Trough, bringing down the highest beds of the Oil Shale Group. On the east side of the depression there is the well-known Broxburn anticKne (see Fig. 12) in continuation with the Pumpherston arch ; to the west there is another anticline at Binny, with two shallow basins of the Houston Coal further south (Fig. 13). There is a good deal of dolerite present. A reconsideration of Fig. 12. — Section across the northern part of the Broxburn Shale-field. the abundant evidence afforded by bores and mining operations shows that. there are three distinct sills, and not one only. These intrusions transgress but slightly from their respective horizons : the lowest underlies the Dunnet Shale, the next lies about the Brox- burn Shale position (Broxburn Sill), while the highest runs between the Fells Shale and the HoustoTi Coal. The lowest strata yet proved in this region belong to the Dunnet Sandstone Group, and were recently pierced in the Wyndford diamond bore, put down on the east side of Binny quarries. The Burdiehouse Limestone was not recorded, though the bore went down 108 fathoms 5: Fiti. 13.— Section across the soutliern part of the Broxburn Shale-field. below the Dunnet Shale position (reached at 30 fathoms). Very few sandstone beds were found, most of the strata consisting of fakes and ])laes, with occasional limy ribs. For the last 30 fathoms, the beds had a strong oily sm.cll, and several thin " whinstone " ribs were met with, so that the Camps Shale is probably useless in this part of the district. Dunnet Shale.— A single seam of shale, from 8 to 10 feet thick, is found in the Dunnet position, and is now being worked to the north and east of Broxburn, by two long mines driven down from the Brox- burn Shale. Near Stewartficld a dolerite sill lies close under the Seam, this being an extension of the great Houston Wood intrusion of the Pumpherston field. To the west, beyond Uphall and Binny, borings show that the Shale is valueless, being represented by strong dark blaes ; but there is no igneous rock hereabouts which could have caused this deterioration. 50 The Geohgy of the Oil-Shale Fields. A fathom or so under the Diinnet Shale there is a thin bed of grey or cream-colonred " marly fakes," probably a fine volcanic tuf? (Barracks Ash), which is a useful index to the shale position : a similar " mark " is found to the north, in the Philpstoun Shale-fields. No representatives of the New or Under Dunnet Shales are known in the Broxburn district, and the Barracks Limestone also appears to be wanting. In an old chi.sel bore at Stewartficld, several " lime- stones " are recorded close under the Dunnet position, but the Barracks Limestone is so thin at Drumrslioreland that it seems more proba^'e tbat these belong to the series of hard limy cements and sandstones that commonly he on top of the Dunnet Sandstones in other fields. To the north and east of Broxburn, the Binny Sandstone G-roup is developed strongly, there being 50 to 60 fathoms of sandstone strata in this position — a considerably greater thickness than at Binny itself. Resting on the sandstone is the Lower Grey or Champfleurie Shale, found in several thin bands with partings of blaes. At Binny quarries these shaly beds contain abundant entomostraca. The seam is not workable at any point, and is succeeded by 10 to 13 fathoms of marl, on which lie the Broxburn Shales. Broxburn Shales. — There are three valuable seams in this position, with other thin shales above, the whole occupying 7 to 12 fathoms of strata. An average section lias already been given on p. 41, in comparison with the sequence at Oakbank. r3n the eastern limb of the Broxburn anticline the Curly Seam has been wrought to a considerable depth, and near East Mains it is rendered useless by the intrusive dolerite sill, which lies a short distance above it. " At the mouth of the ' Albyn ' mine this in- trusive sheet is in two thin bands and in close proximity to the Shale. The lower one was found to be full of cavities coated with calcite, filled in the heart with mineral wax, yellowish-grey when fresh, and brown after exposure to the air. On analysing the hydrocarbon, Mr. Steuart, chemist, Broxburn, found it to consist of carbon (84'35 per cent.), hydrogen (12'83 per cent.), and nitrogen (ToS per cent.), with traces of sulphur in some specimens. The shale was worthless near this rock, and the hydrocarbon was clearly derived from its distillation, and was subsequently accumulated in the cavities of the igneous material" (Cadell, Trans. Min. Eng., 1901-2, p. 347). Identical phenomena recur in the lower sill found about the Dunnet position, and the mines show that we are dealing with two distinct floats. To the east of Broxburn, beyond East Mains, the Broxburn sill, referred to in detail above, lies in the position of the Broxburn Shales, which are consequently useless ; but north of the village the intrusion rises a few fathoms into the overlying marls, and the shales are unaffected. Broxburn Marls. — These strata, comprising an unbroken series of grey and greenish marls, vary from 20 to 35 fathoms in thickness, and begin immediately above the top shale (Upper Grey) of the Brox- burn Series, The Fells Shale hes on top of them, but this seam, although constant, is too thin to be worked with profit at the present time. The Broxburn Park diamond bore, put down to the S.W. of the village, proved this seam, with the usual limestone band seven feet belovf, resting on the marls. Broxburn District. 51 About 50 fathoms of stra.ta, mostly sandstones and fakes, with beds of fireclay and blaes, separate the Fells Shale from the Houston Coal above, as proved by boring to the west of Uphall. To this thickness there must be added a dolerite sill, which is intruded into these strata, appearing in a series of rock knolls, running in a very regular manner between these seams as they curve round the Middleton Hall Trough from Broxburn to Uphall. This sill, in common with the other two below, maintains much the same stratigraphical position for long distances. It was proved in the Broxbimi Park boring, previously referred to, and the bore went down to the lower " float " in the Broxburn Shale position, and so clearly demonstrated the independence of these two intrusions. Houston Coal. — An average section of this seam in the Broxburn field is as follows : — Feet. Inches. Coal ....... 2 3 Blaes 15 Coal ....... 1 4 The position of the seam is well defined by the line of the old crop pits, which can be traced from the Middleton Hall Fault to the east of Holmes, thence round the north and down the west side of the Fivestanks Basin to near Curledubs : traced in this direction, the underlying dolerite sill is foand to rise gradually, until to the north of Fivestanks it immediately underlies the coal, rendering the seam " blind " and worthless. Further to the south the gentle upward transgression of the sill continues, until at Uphall it overlies the coal. In the vicinity of Houston House, the coal lies in two shallow basins (see Fig. 13). The seam first obtained its name from the workings in this neighbourhood, and although not the lowest worked coal in Scotland, it proved in the past sufficiently valuable to supply this district with fuel. Mr. Forsyth, in his account of the Houston Coal (" Mines, Minerals, and Geology of West Lothian," Trans. High, and Agric. Soc. Scot., 1847) states that in the east basin there were two pits, 22 fathoms deep. The seam was divided by a band of stone, sixteen to eighteen inches thick, the upper portion being a household and the lower an excellent smithy coal. The total thickness was 5| feet, and 300 yards from the bottom of the shaft the seam is " blind " — a change doubtless due to the intrusion of the dolerite. Houston Marls and Two-foot Coal. — These strata have been proved in two bores, one of which, situated 600 yards N.W. of Fivestanks, found the marls to be 35 fathoms thick, with a few partings of blaes. On the top of the marls was the Two-foot Coal, as follows : — Coarse sJiale and ironstone strains „ Blackband Ironstone Shah (good) „ (fair) . Shaly blaes Coal with strains of Blackband Ironstone Feet. Inches 5 5 8 10 1 4 52 The Geology of the Oil-Shale Fields. This composite seam was known at one time as the " Fivestanks Shale," and a trial mine was driven in it from which a bore was put down to the Houston Coal. Little is known of the overlying strata. A bore situated near Middleton Hall went down 7G-| fathoms to the Two-foot Coal, the strata consisting almost wholly of blaes with a few thin ribs of sand- stone and clayband ironstone. Two shales were found, apparently representing the Raehurn and Mwigle seams. The latter lay 28 fathoms above the Two-foot Coal, and consisted of 2 feet of inferior shale with an inch of coal below. The Raeburn lay 33 fathoms above, and was represented by 2 feet 11 inches of shaly blaes, the intervening strata being all blaes with clayband ironstone ribs, one of which was 20 inches thick. In this district the Raeburn Shale was at one time worked open- cast to the south of Fivestanks, many years ago. The highest bed of economic interest in the Broxburn field is a blackband ironstone which occm's in the basin round Middleton Hall, a section of which is given below. Feet. Inches. Blackband Ironstone . . . . . . 1| Coal and blaes . . . . . l| B.B. Ironstone , . . . . . 1 if Fireclay . . . . . .02 1 Gi A trial pit proved its thickness to be eighteen and a half inches. Its position is 145 fathoms above the Houston Coal, and the topmost beds, which occupy the centre of this basin, cannot be very far below the Cobbinshaw Limestone. The estimated distance between the ironstone and limestone is 25 fathoms. The Middleton Hall Fault must consequently have a displacement of something like 260 fathoms at this point. 11. Winchburgh and Humble District. {Linlithgow, 6 N.E. ; a small fart in 6 N.W.) This area is bounded on the north by the great Ochiltree Fault, on the west by the canal between Winchburgh and Craigton, and on the south by the Winchburgh Fault, running towards Kirkliston. No shale has ever been worked in this large district, for the Dunnet seam, underlying most of the field, is usually replaced by dark blaes, and the small workable areas of Broxburn and Fells Shales are partially destroyed by dolerite intrusions. Nevertheless, there is good reason to suppose that in the southern part of the district, a large tract of the Pumpherston Shales can be found at a moderate depth, although they do not actually reach the surface. A number of borings, mostly shallow, have been put down, and rock exposures are fairly numerous, although the strata dip in many different directions. With these data at hand, and aided especially by the nature of the foldings seen in the well proved fields to the south and north, we can outline the structure of the field with some confidence. Two important anticlines traverse the district from south to north. Winchburgh and Humhie District. 53 t Q K The first is a continuation of the great Pumpherston-Broxburn Arch, which finally runs out to sea at Hopetoun House : the axis of this arch runs from the east side of Winchburgh village past Dun- tarvie Castle to Woodend, bringing up strata about the position of the Dunnet Shale and Binny Sandstone (see Fig. 14.) The second anticline is a continuation of the Kirkliston arch, and runs northwards through Humbie, bring- ing up the Burdiehouse Limestone west of New Mains ; both of these folds pitch to the north. The intervening trough, in line with the Broxburn- Duddingston syncline, runs through Niddry Mains on past Totty- wells andWestfield, where it brings down a small basin of the Broxburn and Fells Shales, and Houston Coal. Another syncline lies to the east of the Humbie arch, while there is apparently a subsidiary trough north of Ross's Plantation, al- though this is largely a matter of conjecture (see Fig. 14). Apart from the curi- ous degeneration of the Dunnet Shale over the west and central parts of the district, the sedimen- tation is remarkable for the great development of marl and blaes in the Dunnet Sandstone Group, features which are equally evident in the Ecclesmachan field. The Binny Sandstone Group is in strong force, the upper part containing freestones of fine quality. There are two large " whinstone floats," one below the Dunnet Shale position, and forming the tq 54 The Geology of the Oil-Shale Fields. core of the Winchburgh anticline, the other lying over the Binny Sandstone at Humbie. A minor intrusion is found in the Camps Shale west of Kirkliston, but is probably of no great lateral extent. North-west of Winchburgh there is a notable section in the deep railway cutting, 2 miles in length, which terminates at Philpstoun Station. It is almost entirely in solid rock, and when first completed in 1842 very few retaining walls were built. Since then atmospheric denudation, and the vibration produced by the numerous trains which pass daily through this excavation, have caused frequent falls from the rock faces. About four years ago the greater portion of this most interesting section was covered with masonry. The map used by Sir A. Geikie during the original survey records the section as it existed in 1855. Burdiehouse Limestone. — Traces of old limestone quarries can be seen on each side of the public road 300 yards west of New Mains, and again by the Niddry Burn, 500 yards east of Charles' Bridge, on the east side of Ross's Plantation. Fragments of dark banded lime- stone of Burdiehouse type are found in abundance in the fields on the site of the old workings. In the Niddry Burn a thin " whinstone float " lies on shaly blaes, which in turn rests on limestone. North of the main road this intrusion dies out, and bores by the Oakbank Company proved that the lime- stone was 5 feet thick. The limestone crops out round a small arch, probably cut ofi to the south by the Winchburgh Fault. There is little reason to doubt that this limestone is in the Burdie- house position, and allowing for the northerly thinning of the strata below, when traced from Pumpherston, it seems probable that the Pumpherston Shale position lies within 60 or 70 fathoms of the lime- stone at this spot (see Fig. 14). A bore by the Broxburn Company, put down 200 yards N.W. of Ross's Plantation, found limestone at the surface, and went down 37 fathoms into blaes with marly beds, so that another small arch may exist west of the Plantation, before the limestone dips down to- wards Niddry (see Fig. 14). If this is the case there would be over a square mile of Pumpherston Shales in this vicinity, within 100 fathoms of the surface. " When the [Winchburgh] tunnel was originally made, a thick bed of limestone was cut below thick blaes dipping westward at the south end of the opening. The limestone rested on sandstone beds, and had a crystallised burnt appearance, probably due to the proximity of the trap of Winchburgh Hill." * In the summer of 1890, the arched roof of the tunnel, which is 1100 feet in length, gave way, and Mr. H. M. Cadell had an oppor- tunity, while the building was being repaired, of examining the over- lying rock. No oil-shale or limestone could be seen, but near the southern end there was some grey freestone under beds of blaes dipping north-westward at 10° to 20° in some places, and flat in others. At the northern end a good deal of white trap was visible and white shaly and marly beds, apparently altered by the intrusive rock. These strata were probably mistaken by Forsyth for limestone, as boring and other * " Mines, Minerals, and Geology of West Lothian," by Mr. Charles Forsyth, Transactions of ihp Highland and Agricultural Society of Scotland, 1847, p. 259. Winchburgh and Humbie District. 55 evidence in the vicinity suggests that the Burdiehouse position lies 100 fathoms or more below the tunnel. Dunnet Shale. — The exact distance from the Burdiehouse Lime- stone up to the Dunnet Shale is not known in this district. In one boring, S.E. of Humbie, it was 25 fathoms, but probably a fault was passed through, and the full distance may be about 50 fathoms, increas- ing to over 100 fathoms at Winchburgh. The Dunnet Shale round Humbie is represented in several borings by thick beds of shaly blaes ; and further west the seam disappears altogether. A deep diamond bore by the Oakbank Company at Swine- burn found the Shale burnt out by an extension of the Winchburgh dolerite sill, the position being represented by 8 fathoms of dark blaes, with the " whin " below : near the contact with the igneous rock beds of marly blaes showed a remarkable development of small white spheroids. A similar result attended a boring in 1888 at Beattlie quarry, half a mile N.E. of Winchburgh. It is probable that the grey blaes in the brick pit west of Winch- burgh Station lies about the Dunnet position, and also the papery blaes with hard cement ribs seen in the Oakbank Company's tramway cutting east of Duntarvie Castle. Borings suggest that the Winchburgh dolerite " float " lies at the surface almost as far as Duntarvie Castle, along the crest of the Winchburgh anticline, without any change of horizon ; there is therefore no hope that the Dunnet Shale is workable anywhere in the western part of the district. The sill dies out eastwards towards Humbie. Binny Sandstone Growp. — These strata are 55 fathoms thick in the Swineburn diamond bore, and mostly consist of sandstone, but west- wards, thick beds of blaes, with some marl, are found in the lower position. At the top are excellent beds of freestone, seen in the well- known Humbie quarry, now long disused, and in other abandoned quarries at Craigend, west of Swineburn, and at Glendevon. In the railway cutting at Priestinch, 56 feet of massive sandstone, with blaes partings, are seen in this position. The old freestone quarry by the roadside 400 yards north of Duntarvie Castle is apparently on this horizon also, for a bore here in 1885, after passing through 16 fathoms of sandstone, went through 13 feet of " black sandstone." Black sand- stone was noted in the old Survey field map below the main post of Binny Sandstone in the railway cutting at the loop-line junction, and Forsyth makes special reference to this exposure as being a remarkable feature of the district. The Champfleurie, or Lower Grey Shale of Broxburn, rests on the Binny Sandstone, and was represented in the Swdneburn diamond bore by 5J fathoms of blaes, with bands of shaly blaes, and dark Hniy ribs with entomostraca, as at Binny. In this boring it was separated liom the Broxburn Shale by nearly 17 fathoms of grey sandstone, with curious mammilla ted cement concretions, an inch or more across. In the railway cutting east of Auldcathie bridge, the sandstone is replaced by grey marls with thin limy ribs. Broxburn Shale. — In the railway cutting 80 yards E. of Auldcathie bridge, tlie Broxburn Shales arc represented by 9 to 12 feet of black bituminous blaes, with shaly layers. Borings suggest that the sudden attenuation of this important shale group continues northward past 56 The Geology of the Oil- Shale Fields. Duntarvde up to the Winchburgli anticline. West of the arch, however, the Shales resume their normal character, in the syncline between Totty wells and Westfield. The Swineburn diamond bore, which began just above this group, found a typical succession of three seams, "grey" "curly" and "plain." On the east side of this small trough the Shales are affected by the Dundas Castle sill, which has apparently also spoilt them on the east side of the Humbie arch. This sill lies below the Binny Sandstone at Craigend quarries, but rises gradually towards the west, until at Humbie quarry it rests on the sandstone. Further west it probably dies out, as no trace of dolerite was met mth in the Swineburn boring until below the Dunnet Shale position. Broxburn Marls. — The railway bridge at Auldcathie, already mentioned, stands on the Broxburn Marls, east of which point the " Upper Grey " Shale of Broxburn is succeeded by greenish marls, and on the west side the marls contain thick ribs of limy cement. These strata extend for about 100 yards along the cutting, when they are cut off by a fault with a low hade, down west, bringing the marls against a series of grey blaes with ironstone bands. This fault, or else another beyond where the cutting is walled up, must have a considerable throw, as the Houston Marls crop out within a short distance. The Fells Shale is not visible, and its thickness does not seem to be known in the Tottywells Basin. Houston Coal. — -There were several crop pits to this seam near Craigton, and Forsyth mentions that on " the south side of the canal it was wrought by a shaft IG fathoms deep." This pit is interesting, as marking the furthest point to the north-east where this coal has been wrought in the Lothians. To the east of Craigton House, on the south side of the Ochiltree Fault, its position has been proved in numer- ous bores, one of which, near Duntarvie, found 3 feet 9 inches of coal with three fireclay partings a few inches thick, underlaid by 2 feet 5 inches of fakes with a 3-inch ironstone rib, and 11 inches of coal below. Between Tottywells and Westfield the outcrop of this coal is said to have been got. Fragments of coal have also been picked up there on the surface, which affords additional evidence of the extension of the basin already mentioned as containing the Broxburn Shale. The overlying Houston Marls are exposed in the railway cutting below Craigton House, and are the northern extension of the outcrop already mentioned as occurring in the Little Ochiltree Basin. At this point they are composed of green and red marls with ironstone bands. 12. Ecclesmachan District. {Linlithgow, QN.W., S.W.) This area is bounded on the south by the somewhat ill-defined line of faulting found to the south of Ecclesmachan and Winchburgh, and on the north by the Ochiltree Fault, which dies out in the western part of the field. A small portion is included on the south side of the Ecclesmachan Fault, round East Broadlaw. Both the Houston Coal and the Broxburn Shale have been wrought ; Ecclesmachan District. 57 3yo9 via 5$ ^5 t tCuj s5 ■ 3yoa 90-b^hf y\ Q W in tlie western part of the field large areas of the Broxburn Shale have been destroyed by the Binny Craig dolerite sill. The strata are arranged in a somewhat complex system of folds, most of which are essentially prolongations of others found further south, in the Broxburn field. Thus, to the east, at Niddry Rows, a sharp arch in the Brox- burn Shale marks a northerly extension of the Broxburn anticline. West of Hope- toun Oil Works there is another arch in this shale which is also developed in the Broxburn field (see Fig. 15). Round Hill- end, two shallow basins of the Houston Coal indicate the northerly limit of the great Middleton Hall Trough, followed to the west by an arch in the Broxburn Shale, in line with the Binny anticline. East of Eccles- machan, the most extensive fold in the field — the Oatridge and Little Ochiltree basin — can again be traced through the Broxburn field down to Houston. On the west side of the district, round Hangingside, another sharp anticline brings up the Broxburn Shale, and is a part of the long anticlinal ridge which extends from Wester Breich, through Dechmont on to Philpstoun. This fold has an important bearing on the interpretation of the obscure ground round East Broadlaw. There is a well-known volcanic neck at Tar Hill, on the north side of Eccles- machan, which has already been described on p. 13. Burdiehouse Limestone. — Between East Broadlaw and Binny Craig there are traces of old limestone quarries now filled up. Scattered fragments of dark limestone con- taining entomostraca, fish and plant re- mains, were here picked up by Sir A. Geikie during his survey. These quarries probably mark the position of the bed of limestone, " 200 yards south from Binny Craig, which has been wrought at Broadlaw, 11 feet thick, and of a blackish colour, and dipping eastwards" ("Mines, Minerals, and Geology of West Lothian," by Mr. Charles Forsyth, Trans. High, and Agric. Soc, Scot., 1847, p. 257). What is this limestone ? Beds of simi- lar cliaracter are known in this district, below the Fells Shale, in the Broxburn Marls, and again close under the Dunnet Shale (Barracks Limestone), but they have rt ^ 58 The Geology of the Oil-Shale Fields. all been bored through in the immediate neiglibourhood (Oatfidge, and the Wyndford and Forkneuk bores) and none of them was more than a foot or so thick. It seems very probable that the Broadlaw Limestone is in the Burdiehouse position. Both in the Philpstoun field to the north and round Dechmont to the south, the Burdiehouse Limestone is of a dark banded type, and is from 10 to 12 feet thick. Again, the Ecclesmachan Fault is known to have a downthrow north of 100 fathoms at East Binny, so that if it continues its easterly course along the south side of the Binny Craig dolerite sill, which is known to be in the Broxburn Shale position, the strata between the Craig and East Broadlaw must he just about the Burdiehouse position. On that hypothesis the fault turns south-west, alter passing the Craig, running through West Binny, for the Houston Coal is reported to have been worked at West Broadlaw. The strong anticline found round Hangingside extends south- wards, and can be seen in the Binny Burn just below the reservoir. The whole evidence suggests that the Broadlaw Limestone is the Burdiehouse, and that it appears on the crest of an anticlinal fold (see Fig. 12). The Camps Shale is probably valueless hereabouts owing to whin intrusions, but the Pumpherston Shales below may well be in good condition ; they shoidd be within 60 fathoms of the limestone in this region. The absence of any representative of the Dunnet Shale in the well bored ground between East Broadlaw and the small basin of the Broxburn Shale mapped on the west side of Binny quarries, is accounted for by the " want " in this seam all over the district. Dunnet Shale. — There is little reason to suppose that the Dunnet Shale will ever be found in workable condition in the Ecclesmachan field, except perhaps under Hopetoun Oil Works, where it lies 80 fathoms below the Broxburn Shale. There is no hope that this seam is of any value in the western part of the district. Borings in the neighbouring part of the Broxburn field at Wyndford and Forkneuk, and in the Philpstoun field at Bridgend, have all been unsuccessful. The degeneration is apparently not due to any igneous intrusion, but arises from non-deposition of oil-bearing sediments when the strata were originally laid down. The Binny Sandstone Group is well developed, about 50 fathoms of sandy strata being proved in borings at Hopetoun and Glendevon, in the latter case there being some fathoms of dolerite in the lower part of the series. The Chatnpfleurie (or Lower Grey) Shale, which rests on the Binny Sandstone, is not workable in this field ; it is separated from the Broxburn Shale above by 15 to 18 fathoms of blaes, sandstone and marl beds. Broxburn Shale. — This seam has been extensively worked, and most of the available shale has been taken out. At Glendevon mine, Young's Oil Company are now working the Upper Grey seam. On the west side of the Little Ochiltree trough, Messrs. James Ross & Co. mined the Broxburn Shale from its outcrop to a vertical depth of 150 fathoms from the surface ; the average section was 7 feet 10 inches of shale, parted by two half -inch cement ribs, the roof Ecclesmachan District. 59 being of blaes. The seam has also been wrought by a mine two-thirds of a mile to the south of Glendevon, which was driven down 45 fathoms from the surface. At Hopetoun Oil Works, on the north side of the Niddry Fault, No. 2 Pit, 70 fathoms deep, has proved the steep syn- cline on the north-west side of the Broxburn anticline. On the west side of the field, round the Hangingside anticline, the Shale has been largely destroyed by the Binny Craig dolerite, which is possibly an extension of the sill associated with this position in the Broxburn field. Two bores, one to the south of Little Ochil- tree, the other one-third of a mile north of Oatridge, found that the sill had totally destroyed the shale, and in the igneous rock there were cavities filled with a soft yellow wax, as is commonly found in similar cases elsewhere (see p. 50). The Fells Shale, which lies about 32 fathoms above the Broxburn seam, round Little Ochiltree, has often been proved in bores, but is not yet worked. Houston Coal. — This coal lies from 40 to 50 fathoms above the Fells Shale ; the intervening strata, mainly faky sandstones with plant remains, are visible in the Mains Burn, to the north-west of Ecclesmachan. The coal has been worked to a considerable extent in past times chiefly in the two Hillend Basins, and much information relative to these worldngs is given in Mr. Forsyth's report, cited above. On the west side of the Little Ochiltree Basins, the Linlithgow Oil Company drove two mines into the coal and used it for the fur- naces and retorts. On the east side of the basin numerous old crop pits indicate the position of the seam : the following section occurs at Drumforth : — Feet. Inches. Coal 13 Dirt ....... 3 2 Coal . 1 10 In the little basin north of Hillend a 4-inch rib of cannel was found in the coal, but the roof of the seam is generally weak, and the coal itself so full of pyrites, and stone and fireclay ribs, as to be an un- profitable subject, except during times of scarcity and high prices. At Glendevon a roll-over of the strata brings down a narrow strip of Houston Coal, Vvdiich is thrown against the Broxburn Shale by the Winchburgh Fault. This dislocation begins near Waterstone and increases rapidly towards the east, the southerly downthrow, where it crosses the canal at Winchburgh, being at least 160 fathoms. Houston Marls. — The Houston Marls appear to occupy the whole of the Oatridge Basin, and can be traced onwards beyond Three Mile- town into the railway cutting at Craigton. In the burn, half a mile north-west of Ecclesmachan, these strata are exposed in a fine section of green and red marls with bands of pale green micaceous sandstone. Ttvo-joot Coal.— In this district the Two-foot Coal is associated with a volcanic series, consisting of both lavaform and fragmental rocks. A good example of the latter is the purplish sandy and fels- pathic ash, exposed in the old quarry to the north-east of Little Ochil- tree, which has a rudely confused dip and contains abundant fragments 60 The Geology of the Oil-Shale Fields. of black shale (Fig. 16). This ash bed can be traced for several miles on the west side of the Lothian Shale-field, and marks an early stage in the great volcanic eruptions which took place in the Bathgate and Linlithgow districts towards the close of the Oil-Shale period. 13. Champfleurie and Philpstoun Shale-fields. {Liodithgow, 2 S.W., 5 N.E. and 6 N.W.) These shale-fields lie to the north-west of the Ochiltree Fault ; an arbitrary line drawn from Craigton to the mouth of the Midhope Fig. 16. — Section of the Champfleurie Shale-field, south of Bridgend. Burn marks their eastern boundary, while to the west the strata pass underneath the Carboniferous Limestone Series. This area has been extensively developed by the mining opera- tions which were carried on in the Champfleurie district by the late Linhthgow Oil Company, and especially by those at present vigorously prosecuted in the Philpstoun area by Messrs. James Ross & Co. Several important additions have recently been made to our knowledge from the mines and borings of the last named firm. The strata in general dip N.W., but this arrangement is modified ft-0« H- J.NIOd CiN 3yos V3ld "^^ "y^ Hxyoj A13I00S W K v''/ , 2 Duddingston Shale-field. 69 sandstone and has probably destroyed the Shales, but on the east side of the Banks anticline, rises rapidly, so that the seams may be work- able south of Port Edgar. This dolerite underlies the Shales in the Duddingston Basin, and practically dies out to the N.W., although it is present in strong force over the Philpstoun field. The Pumpherston Shales seem to degenerate northwards, and are in very poor condition on the shore beyond Hopetoun House. In the south-west part of the field they outcrop in small folds on the crest of the Hopetoun arch, in Hopetoun Wood, where they have been proved by boring. Burdiehouse Limestone. — This limestone, 5 to 15 feet thick, was at one time extensively worked on the south-west side of the Duddingston Basin, round Newton. Borings indicate that the small syncline of this limestone shown on the published maps south of Hopetoun House is not detached, but is in direct connection with the main outcrop to the east (PI. III.). The Hmestone has been quarried out on the shore sections near Banks, and on each side of the Hopetoun arch, and is best seen to the north-east of Hopetoun House. It is a dark banded rock, with grey or creamy weathering, and glassy fracture, and is very pure. In all three sections it is underlaid by one or more bands of limy cement, weathering with a bright yellow ochreous crust ; these cements contain small worm-tubes, and are similar to the lower of the two Queensferry Cements, under the Pumpherston position. In the Banks section these cements are intersected by thin' " sandstone dykes," which owe their origin to fissures that were formed after the partial or complete solidification of the beds, and were subsequently filled up with sand, probably sifted from above. Hence it is probable that the limestone set into a hard rock before it was overlaid by any great depth, of sediment. At the fijst glance these dykes simulate the appearance of an igneous intrusion, and in all probability the "sand- stone conglomerate," which traverses the same limestone at Port Edgar, as recorded by Mr. Cadell (" Trans. Inst. Mining Engineers, vol. xxii, p. 363), had a similar origin. Camps Shale. — Over the limestone is a blaes bed 5 to 9 fathoms thick, containing two bands of shale mixed with shaly blaes. These represent the Camps Shale, and die out northwards, being replaced by .shaly blaes on the shore section. Dunnet Sandstone Group. — ^These strata vary from 28 to 36 fathoms, thickening northwards. In the lower part, the Port Edgar Ash noticed in the Philpstoun field has been found in bores, where it is 6 to 12 feet thick. This ash rests on a few feet of grey hmy cements and " kingle " sandstones with oolitic grains, as in the Philpstoun shale-field. The sandstones below, so well developed to the south- west, are in this field only a few feet thick. In one bore (No. 12) on the coast east of Society, the ash was only 9 fathoms above the Burdiehouse Limestone. Bores between this point and Bridgend, near Philpstoun, show that a progressive thickening of the intervening strata sets in towards the south and south-west. There are from 20 to 30 fathoms of strata between the asli bed and the Dunnet Shale. Round Duddingston these beds mainlj^ consist of dark marly blaes, with a few ribs of sandstone and limy cement in the upper part. Northwards the blaes is largely replaced by coarse 70 The Geology of the Oil-Shale Fields. SHORE SECTION, QUEENSFERRY TO WHITEHOUSE POINT. Feet. Inches. DuNNET Shale ...... 5 Barracks Ash Soft yellow marl rib, pyritous . Sandstone . Fault 5-10 fms. Camps Shale (with light ashy rib at base) BuRDiEHOUSE Limestone, dark, glassy fracture Blaes Dark limy blaes, entomostraca, etc. Blaes and bands Cement, weathers yellow, small worm- Blaes, faky Sandstone . Dolerite sill, pale blue Sandstone, yellow . Faky blaes " White Trap " (Hopetoun Sill) Cement, striped, irregular 'Shale and shaly blaes, with two irregular ribs of limy cement, each 9 in Blaes and ribs PuMPHERSTON Shaly blaes and dark cement ribs Shales Black blaes and cement ribs Gap (Burn mouth) Shale, good, plain Blaes, dark, papery PuMPHERSTON /Marine shells {Orthoceras, etc.) in grey blaes. Shell Bed [ pyiitous, like " alum shale " 1 ft. to 1 Blaes, dark, papery ... 4 6 300 . 3 5 12 2 33 tubes 1 19 42 2 93 11 2 6 1ft. to 4 ar ribs of 5 15 14 8 3 6 8 Cements QUEENSFERRY f ^'^BJ^^ef ^' ^^^^^^'-^'^^'^''^^g' ^^^^^^'^ (.Cement, cream-coloured, with worm-tubes Blaes and thin cement ribs No. 1 Shale, curly Shaly blaes .... Blaes .... Shaly blaes .... Cement, with small chips of blaes, etc. . Faky blaes and faky sandstone Gap .... Faky blaes .... 'Shaly blaes .... (?)DAIiMAHOY No. 2 Shale, good, plain Cement I'ib. Shale, plain .... , Shaly blaes .... Sandstone, etc., flaggy Gap .... Sandstone, coarse, yellow, in beds . Faky blaes with ironstone ribs Gap .... Marly blaes, indurated, with small white spheroids Dolerite sill (Mons Hill) . - . 1 2 6 15 ft. to 2 1 2 1 40 36 2 2 1 1 to 6 49 74 156 51 84 ft 45 Queens ferry and Dalmeny Shale-fields. 71 brown sandstone, which was 22 fathoms thick in a bore on the coast 200 yards S.E. of Society Point. This bore was put down within a few yards of the dark greenish agglomerate seen on the shore, and con- firmed the suggestion of Messrs. Cadell and Grant Wilson that this was a volcanic neck (Fig. 19.), for no material of this natiu:e was passed through until the Port Edgar ash was reached at 53 fathoms, Du7inet Shale. — The Dunnet Shale is well exposed on the shore immediately west of Society. It occurs in two bands, each about 5 feet thick, the lowest being of excellent equality ; they are associated with 14 feet of mixed shale and blaes, with fish remains. The Shale rests on a black carbonaceous ironstone crowded with fish remains, and west of Hopetoun is again visible on the shore, resting on a three- inch bed of light greyish tuff (Barracks Ash), as at Philpstoun. The inland outcrop of this shale round the Duddingston Basin was first traced by Mr. Cadell, on the Geological Survey map, many years ago. Subsequent boring by Mr. James Jones, of the Dalmeny Oil Company, proved that this work was perfectly correct,' and the seam has since been extensively worked by the Oakbank Company from Nos. 1 and 2 mines, Duddingston. The Society Point bore, above referred to, found 13 feet of marly blaes with cement ribs over the Shale, succeeded by 17 fathoms of sandstone with faky partings, well seen on the shore. These strata represent the Binny Sandstones, and are the highest in the field. 15. Queensferry and Dalmeny Shale-fields. {Linlithgoiv, 2 S.E., 3S.W.,6 N.E. and 7 N.W.) These fields lie in the north-east corner of the West Lothian Shale region, near the Forth Bridge, and are separated by the Ochiltree Fault. The Queensferry field lies to the north of this dislocation, most of the component strata being well exposed on the shore section, especially as regards the sequence below the Burdiehouse Limestone. The Dalmeny field contains strata up to the Houston Marls, and the Broxburn Shale has been worked here for a prolonged period, being now almost exhausted. Both fields are traversed by a deep syncline, broken in the centre by a small arch, which broadens out southwards beyond Dalmeny. These folds all pitch to the north. The Ochiltree Fault divides at Dalmeny, and a branch proceeds south-eastwards towards Cramond, the other continuing eastwards. A small dislocation, down west 5 or 10 fathoms, is seen on the shore immediately east of the Forth Bridge, and joins the Ochiltree Fault south of Queensferry. In the Queensferry field, recent work has led to new views in the reading of the shore section. It now appears that the bed hitherto known as the Burdiehouse Limestone is a Hmy cement underlying the Pumpherston Shales, and the marine shell bed of Pumpherston and Duddingston has been discovered on top. The " Dunnet Shale and Limestone " of the pubHshed maps are in reality in the Camps Shale and Burdiehouse Limestone positions, and are faulted against the Dunnet Sandstones to the west (see Fig. 19). The " Broxburn Shale " at Queensferry has now been identified as the Dunnet Shale, n The Geology of the Oil-Shale Fields. and the whole sequence, as revised, tallies remarkably well with that at Duddingston and Society. Some new points have also been noticed in the Dalmeny field, particularly in regard to the outcrop of the Pumpherston Shales. Queensferry Shale-field. This field will probably be an important one in the near futiu:e. The Dunnet, Camps and Pumpherston Shales arc all in fair con- dition, while seams are also known below the Pumpherston, one being six feet thick ('? Dalmahoy Shale). Much of the ground between Queensferry and Dalmeny is built over, but below sea-level a large area of shale is still available. A revised table of the strata visible on the coast section is given on p. 70 : the beds under the Burdiehouse Limestone are best seen east of the Forth Bridge, while those above that position are exposed round Queensferry, on the west side of the main syncline. The strata below the Queensferry Cements (which lie at the base of the Pumpherston Shales) are indifferently exposed, and there is some faulting on the west side of the Long Craig Pier. A diamond 1^. iv qUC£»SF£nitY "^t^VV.irN. E.I6S. 5^ DALMENY | o- to Yia. 20. — Section from Queensferry across the Dalmeny Shale-field. bore situated 600 yards S.W. from the Long Craig Lodge proved four shale positions in these strata, two of which are seen on the shore (Nos. 1 and 2 in table) ; No. 2 shale, seen at low tide immediately west of the Long Craig pier, may be the Dalmahoy Shale, and is the lowest oil-shale of good quality yet known in the Lothians. The Queensferry Cements form the long ridge running out to sea 230 yards west of the Long Craig Pier. They are calcareous, but can hardly be termed true lim.estones, as are those of the Burdiehouse type : the lowest bed has been quarried on the shore to a slight extent, but must have been of little value. The marine shell bed, just above, weathers like an alum shale, with an efflorescence of gypsum, and,hke the cements below, is identical in character with the equivalent strata on the Hopetoun coast section. Diamond bores to the south-west found the overlying Pumpherston Shales better than on the shore, three good seams being proved, although the ammonia yield is not quite so high as at Duddingston ; these Shales are now being opened up by a mine on the east side of Dalmeny Station. The bores also passed through several thin dolerite sills, as on the shore : these intrusions represent the most easterly continuation of the Hopetoun " float," and lie at a much higher horizon than the great Mons Hill sill (see Fig. 19). Burdiehouse Limestone. — The Biurdiehouse Limestone,dark coloured, banded, and with its characteristic glassy fracture, is exposed on Queensferry Shale-field. 73 the shore at low tide 80 yards east of the Forth Bridge. Part of the Camps Shale above is visible, faulted against sandstones which are known to be covered by the Dunnet Shale fiirther west, but the Port Edgar Ash, which is here only a few feet above the Camps Shale, is thrown down out of sight. On the west side of the Queensferry Trough, the limestone reappears ; in the old workings at Port Edgar, known as the " Dundas Limework," it was from (3 to 9 feet thick, dark in colour, and contained some iron. The limestone was in three beds, and was traversed by a dyke of so- called " sandstone conglomerate " divided in the centre by a vein of spar, containing galena, and running in a north-westerly and south- easterly direction. In the workings at Echhne, the limestone was pierced, at one place, by a dyke of igneous material, perhaps an off- shoot from the main mass of eruptive rock found to the west. There is a small exposiu-e of this limestone in the old quarry on the south side of the Dalrneny Railway Station and Society road. Here it is a dark-coloured rock of freshwater origin, and, from this point, the course of the working can be traced by " sits " or subsidences into the " waste " in the fields north and south of Echhne Farm. To the south it is cut off by the Ochiltree Fault. The Hopetoun sill, which is such a prominent featiu-e in the centre of the Banks anticline west of Port Edgar, underlies the Pumpherston Shales in the Duddingston Basin : north of Lawflat it is involved in these Shales, while at Inchgarvie it rises above into the sandstone, as can be seen at the cross-roads west of the Port Edgar lime workings. On the east side of the Queensferry Trough, as noted above, the sill has almost disappeared, but still lies above the Shale. Consequently it is inferred that around Port Edgar and under the Queensferry synchne the Shales may be quite workable at a shallow depth (see Fig. 18), and there is in addition the probability that the underlying seams seen east of the Forth Bridge may also be got. Dunnet Shale and Sandstone Group. — In the railway cutting at Port Edgar there is an excellent section of these strata, shown in condensed tabular form below : — SECTION IN THE PORT EDGAR RAILWAY CUTTING. Grey sandy blaes, blocky . Grey blaes and thin ironstone ribs Strong dark blaes . White trap (dolerite sill) . Burnt blaes and daugh Dunnet Shale, plain Barracks Ash Soft yellow ash rib and daugh, pyritous with parting of shaly blaes Brownish grey sandstone, in heels Gap (mostly sandstorfe) . Dark blaes with cement ribs Port Edgar Ash Sedimentary breccia Dark blaes and cement ribs Dark grey limy sandstone, faky at top Dark blaes and cement ribs Black sandstone, limy Blaes and thin sandstone ribi Dark irony limestone, fish teeth, etc. Blaes and cement ribs Feet. Inches 10 20 a 5 1 5 1 2 5 I 65 30 137 37 S IB 2 9 1 2 1 I 4 8 74 The Geology of the Oil- Shale Fields. The Burdiehoiise Limestone has been mined a few feet below, and " sits " can be seen round the bridge near the shore. The Port Edgar Ash is very well seen near the west end of the cutting. This most remarkable bed is here at its maximum, being 37 feet thick, and is of the same type as at Duddingston and Philpstoun. It is composed entirely of sedimentary materials, set at all angles in a dark sandy matrix. The fragments (some very angular, others rounded) mostly consist of clay ironstone, cements, or dark blaes, such as are found in the strata immediately above or below. The occasional presence of foreign material (coal, yellow pyritous sand- stone, etc.), and of irregular lenticles of blaes 3 feet or more in length, suggests that the rock is not a desiccation breccia, but is more probably due to a dust explosion proceeding from one of the numerous volcanic necks which are found on either side of the Forth. At the same time it is a remarkable fact that there seem to be no fragments of the Burdiehouse Limestone, which lies only 10 fathoms or so below at this spot. Mr. Cadell suggests that the breccia may have been thrown out from a parasitic cone resting on a dolerite sill intruded about the Camps Shale position early in Carboniferous times, when only a few feet of sedimentary cover had been deposited on the Shale. The theory does not seem impossible, and certainly intrusions of teschenite are known at this level further south, near Kirkliston. Such an unique phenomenon deserves further investigation. It may be remarked that at Philpstoun the Port Edgar Ash lies high up in the Dunnet Sandstone Group, but going east the under- lying strata thin out, while those above expand, until at Queensferry the Ash lies only a few fathoms above the Burdiehouse Limestone (see Plate XL). The ribs of hard limy cementstone that are found in the blaes above the Ash in the cutting are intersected by many small reversed faults, apparently formed during the original consolidation of the sediments, as they rapidly disappear in the smTOunding blaes. The succeeding sandstones are partly visible in the cutting, further east, and again on the shore section. They are soft false-bedded strata, with no good freestone beds. West of the harbour they contain one or two ribs of oolitic cement on much the same horizon as at Rosyth and in the shale-fields to the west and south-west. Dunnet Shale. — The Dunnet Shale, 5 feet thick, is well seen in the railway cutting at Queensferry Goods Station. There is a light grey, yellow weathering rib of ashy sediment in the floor of the seam, resting on the sandstones below as at Society, Philpstoun, etc. (Barracks Ash), and with much pyrites dust. The thin sill of white trap in the roof of the seam has no great effect on the shale. Practically identical sections are seen in the harbour, and in the small glen to the west of Rosehill, the seam being repeated by a sharp anticline east of the harbour at The Craigs', pitching to the north. There seems to be no reason why there should not be a large area of this Shale available beyond tide-mark, as the associated dolerite sill is at its maximum in the Dalmeny field, and is apparently dying out to the north. The identification of this seam is of considerable economic import- ance, owing to the data afforded as to the depth of the Camps and Pumpherston Shales below. The chief reasons for considering that Dalmeny Shale-field. 75 it is the D linnet and not the Broxburn Shale are (1) there is no trace of the Broxburn Curly and Grey Shales, which should be immediately above, as at Dalmeny ; (2) the ash rib in the floor of the seam agrees with that found below the Dunnet in the other shale-fields ; (3) the field evidence west of Queensferry gives only 53 fathoms of strata between the Shale and the Burdiehouse Limestone at Port Edgar ; (4) the sand- stones below are of poor quality, very unlike the excellent Binny freestone of the Dalmeny quarries. Dalmeny Shale-field. This area comprises the tract which lies on the south side of the Ochiltree Fault between Dundas Castle and Cramond. In this field we find the southern prolongation of the compound syncline of the Queensferry Basin let down by the Ochiltree Fault so that it contains strata above the Houston Coal. The line of the Ochiltree Fault forms its northern boundary, the displacement at Dalmeny Station being about 235 fathoms, as the Houston Marls are brought down against the Pumpherston Shales. Mining and sm-face evidence shows that the fault divides east of this point, one branch running due east, while the other branch trends further south towards Cramond. Burdiehouse Limestone and Pumpherston Shales. — On the east side of Dalmeny village, the Binny Sandstones have been worked in a large quarry, and dip westwards at 35° to 40°. If this angle of dip continues, the Burdiehouse Limestone and Pumpherston Shales must be brought up a few hundred yards south-east of Easter Dalmeny (see Fig. 20), faulted against the Craigie dolerite (Dunnet position). The Dunnet Shale is useless here, a diamond bore put down in the quarry finding 46| fathoms of " whin " with 15 feet of burnt shale immediately beneath. But the Pumpherston and Camps Shales should be untouched, for the Hopetoun sill has practically died out to the north-west, and the Mons Hill " float " lies much too far below to affect the shales. Dunnet Shale. — The whinstone found in the quarry bore, over this Shale, was again proved in much the same position on boring west of the railway, and probably rises to the south and continues round the syncline to join the Dundas Castle intrusion. South of Dalmeny, between Craigbrae and Carlowrie Farm, there are several isolated outcrops of teschenite, probably due to repetition of one or more sills by faults running in a general north-easterly direction, with down- throw to the south-east. Further south, borings on Carlowrie estate have proved the Dunnet Shale in good condition ; it seems to lie immediately under the dolerite from Dolphinton House to Carlowrie Farm. To the south-west the sill rises above the Shale, which turns in a N.W. direction through Wheatlands, but after crossing the railway bends S.W. through Almondhill and thence N.W. again towards Humbie ; this sinuous outcrop is more or less parallel with the folding of the Broxbimi Shale further north. Accordingly, between Almondhill and Wheatlands there is in all probability an extensive field of Dunnet Shale, dipping gently to N., N.E. and N.W., which should be unaffected by whin- stone intrusions. 76 The Geology of the Oil-Shale Fields. East of Craigie the Camps Shale should reach the surface, con- tinuing; the outcrop on the east side of the Ingliston syncline (p. 77) from Tm-nhouse School northwards to Burnshot Wood. Unfortun- ately the Shale must here lie along the bottom of the pre-glacial channel of the River Almond, which runs out to sea at Snab Point, and is filled in with 200 feet or more of soft sand, gravel and boulder clay. The Pumpherston Shales should outcrop east of this hne, but are probably all destroyed by the West Craigs sill (p. 77), so that there is little hope of good shale ever being got east of Craigie. Binny Sandstone. — Bores have been put down immediately north of the old quarries in this series at Dalmeny, but no freestone was got, for one of the branches of the Ochiltree Fault must run past the north end of the quarries. Further south there is a good deal of drift, which has probably prevented any exploitation of the stone until the Craigend quarries are reached, at the extreme south-western limit of the field. A diamond bore from the outcrop of the Broxburn Shale south- west of Dalmeny found over 13 fathoms of sandstone at the top of the Binny Series, covered by limy fakes, with 18 inches of shaly blaes above representing the Champfleiuie Shale. Over this seam were 2 fathoms of " whinstone," succeeded by 17 fathoms of " hard cuttery sandstone " close under the Broxburn Shale. Broxburn Shale. — The lower workings in this series of shales are in the " Curly " and " Broxburn " seams. The former, which is the higher of the two, is 8 feet thick, and is separated from the latter by 4 feet of shaly blaes, forming the roof of the Broxburn seam. This lower section, the workable thickness of which is 7 feet, is a little richer in oil than the overlying " Curly seam " and produces 30 gallons of crude oil with 35 lbs. of sulphate of ammonia per ton. The Six-foot seam is the highest of the group, which, at Dalmeny, yields 20 gallons of oil per ton, with 40 to 50 lbs. of sulphate of am- monia. SECTION OF BROXBURN SHALE, DALMENY. Roof, hard limy freestone. Black blaes S^^"- [Shcle . Blaes (Shale, curly CuELY I ., plain Shale. 1 Blaes \Shcde . Blaes, shaly Broxburn (Shale inferior . Shale. I „ good Blaes, soft Pavement, black blaes The mining of the Broxburn Shale at Dalmeny has hitherto been confined to the south and south-east portions of this basin, and although the beds are known to strike south-westwards, and then to bend round and strike northward by Dundas Castle, the Shale has not yet been found workable in that direction, as it is burnt by dolerite intrusions. Ft. In. 2 6 2 6 4 3 5 8 2 3 1 4 3 4 2 6 4 12 Ingliston and Newliston Shale-fields. 77 The Ochiltree Fault cuts off this field to the north, and as this dislocation has a low " hade " to the south, the workable area of the Dalmeny field has thus been considerably diminished. Fells Shale. — The Fells Shale is exposed in the cutting of the Dalmeny and Port Hopetoun Railway, but in this field it is not of commercial value. Below this seam there are several thick beds of sandstone overlying the Broxburn Marls. Houston Coal. — About 220 feet of strata, chiefly grey sandstone and fakes, separate the Fells Shale from the Houston Coal. This well-known seam is apparently in two divisions, separated by inter- bedded tuff and agglomerate, which probably represent the southern extension of the base of the Burntisland volcanic group, as the Houston Coal at Binnend, Burntisland, is directly overlaid by the interbedded volcanic rocks of the Kinghorn area. (Fig. 22). The lower coal and overlying agglomerate are seen in the cuttings of the main line and at the mouth of the Port Edgar branch, but the strata are greatly disturbed and faulted, possibly owing to the proximity of the large volcanic neck under Dalmeny village. The upper coal (about 4 feet thick, with several dirt partings) is well seen in the Port Edgar branch, the fireclay pavement resting on 3 feet of flaggy entomostracan limestone with sandstone and agglomerate below. The coal is covered by 4J feet of shaly blaes (Grey Shale of West Calder, etc.) with 20 feet of blaes and flaggy entomostracan limestone above ; on these the characteristic green Houston Marls are seen, with partings of hard cementstone and reddish marl. 16. Ingliston and Ne-wliston Shale-fields. {Linlithgow, 6 S.E., 7 N.W. ; Edinburgh, 2 S.E.) This area hes to the south and south-west of Kirkliston ; in the centre there is a broad antichne (the Kirkliston Arch), bringing up the Burdiehouse Limestone, with the NewUston field to the west and that of Inghston to the east. At Newliston, Young's Oil Company work the Dunnet Shale, and the seam wrought by the same company at Ingliston was also supposed to be the Dunnet, although the shale differed somewhat from the Newliston section : recent investigation has shown that it is in reality the Camps Shale, the Dunnet only occurring in two small basins in the heart of the syncline. The explored portion of the Ingliston field forms the western limit of a synclinal fold, the eastern limit of which has been partly determined by bores and one pit ; the workings show that the axis of the fold runs E. by N. through Slatebarns. No sections are visible for a long distance on the east side of this field, but strata can be seen dipping west in the river Almond above Cramond Bridge, and in the Gogar Biu-n at Redheughs. Pumjyherston Shales. — In the river Almond, above Cramond Bridge, there is a thick bed of blaes dipping west under the dolerite of West Craigs, and at the top of this series Mr. D. Tait, of the Geological Sur- vey, discovered a marine shell bed exactly resembling that lying at the base of the Pumpherston Shales, while a limy cement below represents the Queensferry Cements. The large whin float above must lie in the 78 The Geology of the Oil-Shale Fields. Pumpherston Shales, which would certainly be destroyed at this point * ; the sill belongs, however, to the quartz dolerite group, and is therefore liable to change its position suddenly, so that there is a possibility that the Shales arc in good condition to the south, about Gogar House. Under the Ingliston syncline, and between Newbridge and Kirkliston, we have no reason to suspect that these seams are affected. Allowing for attenuation of the strata between Pumpher- ston and Queonsferrv. the Shales in this field should not be more than 70 fathoms below the Burdiehouse Limestone. Burdiehouse Litnestone. — On the north side of lh<5 river Almond, half a mile south-west of Kirkliston, a limestone has been quarried, traces of the old workings being clearly seen on the north bank of the river, under the public road, the strata dipping west at a steep angle ; there is a coarse felspathic ash, probably part of a neck, a few yards to the west. Fragments of the limestone are lying about, the stone being of the usual Burdiehouse type. Shallow bores on the west side of one of the old quarries, north of Milhig, proved that the lime- stone was about 7 feet thick, with blaes and shaly blaes above. Sir A. Geikie mapped this bed as the Burdiehouse Limestone, but the out- crop was omitted in the later revision. There is, however, no reason to doubt that his identification was perfectly correct ; a boring here should prove the Pumpherston Shale position within 60 or 70 fathoms, and these seams may actually outcrop a few hundred yards to the cast. On examining a mine section in the Ligliston Pit, the Burdiehouse Limestone (which was, as usual, a dark banded stone with glassy fracture) was found 5 feet thick, and lying 9 feet under the shale workings, which must therefore be in the Camps seam. Resting on the Limestone was a soft light yellow rib, 3 inches thick and very limy ; it might be termed a fine grained marly sandstone, and may contain a large amount of fine volcanic tufJ, as it closely resembles the Barracks Ash at Queensferry and Society. A similar bed rests on the Limestone over most of the shale fields (Queensferry, Society, Philpstoun, Livingston, Newfarm, etc.). Camps Shale. — From 5 to 9 feet of plain shale are worked at Ingliston, with many thick beds of blaes and shaley blaes above the seam, containing thin ribs of soft brown ironstone. The nine feet of strata that separate the seam from the Limestone below consist entirely of blaes. Dunnet Sandstone Group. — These strata are about 75 fathoms thick and consist largely of dark marly blaes with, occasional cement ribs : at the top of the series sandstones appear, 10 to 30 fathoms thick. Dunnet Shale. — The Dunnet Shale has been proved in several borings west of Ingliston House, where it lies in a small basin in the centre of the syncline. Further north the Shale was wrought out about 20 years ago from a pit at Lennie Muir, where it lay in a shallow trough cut off to the north by an east and west fault, down south about 20 fathoms. This dislocation separates the seam from the outcrop further north, about Wheatlands (p. 75). The Shale was from 3 to 6 feet thick, with 4 inches of curly shale in the upper portion. The mine levels show that the Shale at Lennie Muir lay about 75 * A bore put down from the floor of the igneous rock should, within 50 or 60 fathoms, pass through the sha es seen about the Dalmahoy position on the shore section east of Queensferry, but their quality here is unknown. Dalmahoy Area. 79 fathoms above the Camps Shale, which is now being worked north of Boathouse Bridge, from the Inghston Pit, 17. Dalmahoy Area. {Edinhurrjh, 6 N.W., 6 N.E. ; not published as geological ma/ps, hut copies are supplied on special order.) A mile south of Ratho there is an outcrop of oil-shale in the Go^ar Burn between Burnwynd and the Deer Park of Dalmahoy. In the park a steep escarpment runs along the south side of the stream, and about 14 feet of shale can be seen, divided in the centre by a foot of greenish sandy marl. Immediately above are sandstones with " kingle " bands, and underneath are beds of greenish sandy marl, followed by dark, papery blaes. At the bottom, in the bed of the stream, soft blue blaes with clay-ironstone ribs are seen, one of the ironstones being a " mussel band," full of crushed lamelhbranchs. The shale is here practically flat, and is again visible on the northern bank, but to the east a sudden change of dip throws up flaggy sandstones and blaes, beyond which the section terminates. Better exposures of the overljdng strata are seen at Burnwynd, but the shale is here poorer in quality, and much of it can only be termed shaly blaes. The seam was tried many years ago by the Pumpherston and Oakbank Companies, and a few shallow bores put down, but no further operations resulted. An identification of this shale is a matter of great moment, because the field evidence suggests that a large area of gently inclined strata exists between Ratho and Dalmahoy, where shale could be easily wrought. Now this Dalmahoy Shale can hardly be the Broxburn, because there is no trace of the Curly and Grey Shales above, nor of the overlying marls, so characteristic of this position in the Lothians. Neither can it be the Camps Shale, because there is no representative of the Burdiehouse Limestone below. It is fmrther unlikely that it is one of the Pumpherston Shales, because where these seams are known a few miles to the west they are invariably covered by thick beds of dark blaes, with hard slaty limestone ribs and cements ; nor is there any trace of the Pumpherston Shell Bed below. Two suggestions remain — (1) that it is the Dunnet Shale, or (2) that it is a new seam below the Pumpherston position. As regards the former, no lamellibranch band is known below the Dunnet in the Lothians, except in one case (No. 5 Bore) at Duddingston ; while these fossils are very common in the basal part of the Oil-Shale Group, as in the Linhouse Water by Oakbank Oil Works. There is, besides, no trace of the Barracks Ash, which elsewhere is always found in the floor of the Dunnet. It is therefore suggested, not without some hesitation, that the Dalmahoy Shale lies very low down in the Oil-Shale Group, consider- ably below the Pumpherston position. It is an unfortunate conse- quence that, apart from this isolated seam, there is no great likelihood of there being any considerable area of productive shale south of Ratho. There is, however, a distinct possibiUty that a small basin of Pumpherston Shale may be got on the south side of the Middleton 80 The Geology of the Oil-Shale Fields. Hall Fault, round Easter Norton, judging by the presence of a broad syncline at Ingliston, on the north side of the dislocation. 18. Burntisland Shale-field. {No six-inch geological maps published.) The Burntisland Shale-field is the most northerly one in Scotland, and presents many features of interest. The strata outcrop round the end of a broad arch, pitching to the north, which is essentially a prolongation of the great Pentland anticlinal axis, on the south side of the Firth of Forth.' The sediments range from below the Pumpherston position up to the Houston Coal, but, above the latter horizon, are largely replaced BURNTISLAND . Fig. 21. — Plan of the Burntisland Shale-field. by lavas and tufis, which persist continuously up to the Lower Lime- stone Series. From the description given by Sir A. Geikie, it appears that there can be no doubt that the Grange Limestone of Biu-ntisland is the equiva- lent of the Burdiehouse Limestone of the Lothians,* which affords an excellent base line with which to correlate this shale-field with those of the Lothians. On the west side of the Binn of Burntisland the quarries of Kil- mundy and Grange give the following section : — Btjudiehouse Limestone Blaes, with fakes False-bedded white sandstone Liimestone Sandstone .... Limestone The Burdiehouse Limestone is here represented by three beds, separated chiefly by arenaceous deposits, the uppermost of which was first quarried and is now mined by the Carron Company, and the stone is sent to Carron for iron-smelting purposes. This limestone has also been opened out on the east side of Humbie Wood, due west of Glenshee, where it dips E.N.E. below a bed of sandstone, and is about 17 feet thick. A fault probably inter- * " The Geology of Central and Western Fife and Kinross," 31 em. Geol. Survey, p. 46. Ft. In 18 3 to 4 30 7 6 6 2 Burntisland Shah-Field. 81 Ft. In. 16 24 4 10 147 7 15 6 venes between the Humbie Wood outcrop and Dallachy quarry, and from this excavation it can be traced by Kilmundy and Grange quarries till it is cut off by the volcanic agglomerate of the Binn. The Newbigging mine of the Carron Company extends to within a short distance of the Kinross road below Loftheads, where the bed is 15 feet 6 inches thick. The air-shaft recently sunk to the north of Bankhead gives the following section : — SECTION IN AIR-SHAFT AT NEWBIGGING. Surface . Blaes DuNNET Shale Sandstone Blaes BuRDiEHOUSE Limestone On the east side of the Binn the highest bed of this limestone has been quarried at Berryhill and Dodhead Quarries. The outcrop has a north-easterly trend for about two-thirds of a mile in the direction of Kinghorn Loch, and it abruptly turns to the south on the west side of Grangehill. Pumpherston Shell Bed. — In the railway cutting one mile east of Aberdour, Dr. C. A. Matley, a year or two ago, made a most interesting discovery of a marine shell bed with small Producti, &c. It appears to be about 15 fathoms below the Biu-diehouse Limestone, and doubt- less represents the Pumpherston Shell Bed, although, as at Carlops, the fauna is more purely marine than in the main Lothian shale area. There is no trace of the overlying Pumpherston Shales hereabouts, and indeed boring has proved their absence in this field. Dunnet Sandstone. — Between the Burdiehouse Limestone and the Dunnet Shale lies the " Grange Sandstone," the equivalent of the Dunnet Sandstone of the Lothians, which is well exposed in the Grange quarry, Burntisland, where it is 119 feet thick, the bottom not being visible. The Burdiehouse Limestone probably lies 20 feet below. The basal portion, about 70 feet thick, is an excellent " liver rock." It is a very pure greyish-white sandstone, which is extensively used in Fife, Dundee, Edinburgh, and Glasgow, for fine-dressed free- stone blocks. The beds of sandstone, measuring 27 feet in thickness, above the fine building stone, are only suitable for rubble work. The remaining portion of the quarry face, 22 feet, consists of limy sand- stones and fakes. Dunnet Shale. — The Dunnet Shale in the Binnend field lies 100 feet above the Burdiehouse Limestone. Twenty years ago it was extensively mined by the late Burntisland Oil Company, and the following section has been drawn along the line of the longest mine : — SS£ -* GKAUGE. HILL — KNMK COMMON Fio. 22. — Section from Grangehill to Common, Burntisland. 82 The Geology of the Oil-Shale Fields. The Shale varied in thickness from 4 to 7 feet, the bottom of the seam being curly and the top plain with two white ribs. The outcrop of this bed follows that of the Burdiehouse Limestone, and both are extensively affected by the northicast fault which runs through the mined field. The principal mine was situated on the west side of this dislocation, and it followed the shale for 2700 feet from the mine mouth. The seam dips to the N.N.W., the angle of inclination being at first 10°, but gradually increasing to 18° at the face, which lay 900 feet below the surface when operations were suspended. Two faults were crossed at distances from the mine mouth of 1075 and 2060 feet running nearly due east and west, with a downthrow to the south of GO and 51 feet respectively (Fig. 22). On the cast side of the north- east fault the Shale lies on an anticline, a mine being driven along the ridge of this flexure to the north-eavSt, with a branch in an E.N.E. direction. The best Shale was found at the bottom of this mine in the direction of Kinghorn Loch. On the west side of this held the seam deteriorated as it approached the volcanic neck of the Binn, east of which the Shale is exposed on the top of the Grange Sandstones, where it appears to be about 10 feet thick, but diminishing to the west, as proved by the air shaft section. Some years ago a quantity of sjiale was extracted from two trial pits on the Newbigging estate, and practically tested at Pumpherston, but the results of the tests, combined at that time with the want of direct railway communication with the Lothian oil refineries, led to no further steps being taken to develop this field. Binnij Sandstone. — Above the Dunnet Shale at Binnend lies the representative of the Binny Sandstone, which forms a steep escarp- ment just above the old mine mouths, and was quarried and used in the construction of the oil works. Here it is a very inferior stone. On the west side of the Binn the same bed appears at the foot of Silver Barton Hill, above the Grange Sandstone Quarry. Fells Limestone. — At Binnend the Broxburn Shale is not repre- sented, but 210 feet above the Dunnet seam and close to Binnend farm- house there is an exposure of a yellow, ochreous, freshwater limestone about 4 feet thick, resembling the limestone which accompanies the Fells Shale in the Lothians. This correlation is rendered still more probable by the position of the Houston Coal 100 feet above this limestone. Houston Coal. — Before the Bm-ntisland Oil Company ceased opera- tions a cross-cut mine was driven into the shale above the Fells Lime- stone in search of the Broxburn Shale. In doing so they broke into the old workings of the Houston Coal, which was found to be an inferior seam, 13 inches thick, and full of iron p\Tites, with a blaes roof and pavement. This coal mine was regularly laid out " in stoop and room workings," but no record exists as to the period when it was worked. Immediately above the blaes roof of this coal we find the volcanic series of Biu'ntisland, which can now be correlated with the inter- bedded lavas and tuffs of Bathgate and Linlithgow Hills to the west. 19. Districts East and West of Inverkeithing. {No six-inch geological maps published.) On the north side of Inverkeithing Bay, immediately south of Seafield, the late Mr. Bennie, of the Geological Survey, discovered a Rosyth — Burdiehouse and Straiton Fields. 83 shell bed full of marine fossils. The same horizon was subsequently found by Mr. D. Tait in the railway cutting a mile to the north-east. This last-named locahty was thoroughly searched by Mr. Tait and Dr. Lee ; the rich fauna collected so exactly resembles that recently found below the Mungle Shale in the Cobbinshaw boring (see p. 19) that, having regard to the proved wide lateral extent of similar fossil bands, there can be little doubt that these two beds are one and the same. It is consequently inferred that the Broxburn and Dunnet Shale position.^ lie below, and judging from the general attenuation of the Oil-Shale Group in the northern shale-fields, especially at Burnt- island, there seams may quite possibly lie within 100 fathoms below. The strata arc arranged hereabouts in an anticlinal fold, pitching north, and the shales should be nearer the surface on the shore west of Donibristle Bay. The coarse volcanic agglomerate of St. David's may be a neck, or may represent the Burntisland ashes and lavas, which thin out rapidly to the south-west, so that at Dalmeny they have practically disappeared. The whole shore section eastwards to Aberdour (where an oil-shale i'* reported to outcrop in the harboiu") requires re-mapping, and until that is done it is impossible to say definitely whether there is a prob- ability of a valuable shale-field in this district. In the meantime it may be said that the prospects are decidedly favourable. To the west, between Charlestown and Inverkeitliing, there is a broad anticlinal fold, pitching north under the Carboniferous Limestone Series, and broken by many subsidiary flexures, exposed on the shore sections. The Admiralty operations now proceeding at Eosyth have led to the quite unexpected discovery that the Burdiehouse Limestone outcrops in the core of the anticline west of Rosyth Castle. A shaft section beyond low- water mark proved the following sequence : — SHAFT SECTION AT ROSYTH DOCKS. Boulder clay ..... Dark grey quartzose kingle in beds Soft, yellowish, marly Sandstone BrRDiEHOUSF, Limestone, hard grey and massive, with glassy fracture .... 20 6 Hard and soft blaes in beds /"reported by I Admiralty j engineers . 11 Limestone . . . \ . .7 6 Sandstone and quartzose kingle with blaes partings ..... 10 Borings in the vicinity record a few inches of shaly blaes above these strata, representing the Camps Shale. Above the limestone, 40 feet or more of soft, whitish freestone were seen in the dock excavations, the rock being much jointed ; this repre- sents the Grange Sandstone of Burntisland. Resting on the freestone was a light grey, unfossiliferous limestone, 4 feet thick, and crowded with large dark cement concretions, of irregular mammillated form. These nodules are of all sizes, up to a foot in diameter, an.d they appear to be gigantic ooliths, being built up of fine concentric laminae, often centering around a flake of blaes or sandstone. Oolitic cements are common in the Dunnet Sandstone Gioup all over the shale-fields, but the grains are rarely larger than pin-heads. Feet. Inches, 20 1 2 G 84 The Geology of the Oil-Shale Fields. The only bed yet known which is comparable with that at Rosyth, is at a higher level and was noticed in the Swineburn diamond bore between the Broxburn and Champfleurie Shales (p. 55). The south-westerly fault mapped through Rosyth must have a downthrow north of 300 fathoms or more, cutting out the greater part of the Upper Oil-Shale Group, as it brings down the base of the Lower Limestone Series against the Dunnet Sandstones. North of this fault, and inland towards Dunfermline, there must be a large concealed shale-field, but nothing is known as to the condition of the various seams. The quartz-dolerite of Inverkeithing lies in tlie centre of a syncline, which is a northern prolongation of the Queensferry Trough. The dolerite lies above the Mungle Shell Bed of Fordel and St. ])avids, and must be faulted off from the Dunnet Sandstones seen further west round Rosvth Castle. The Castle stands on another quartz-dolerite sill, which is intruded about the Pumpherston position, and brought up in the centre of an anticline. This sill extends to the Du Craig, where recent excavations found it suddenly transgressing, for 20 feet or more, at right angles to the bedding planes of the sediments. 20. Burdiehouse and Straiten Shale-fields. {Edinhurgh, 4 S.W., 7 N.E., S.E., and 8 N.W.) All the shale-fields described in the previous sections are situated to the west or north of Edinburgh and the Pentland Hills, while those now to be considered lie to the east of this range and about four miles south of Edinburgh. The Burdiehouse and Straiton fields (including that of Clippens) /Y.£ BROOMHILL O SCO lOOO 2000 FEET STRAITOfV s.w. LOA/VHE/iD < ^.Q 'o ^ KUj ^C: ^) :^"5i ^ "^ nni. Oeol., vol. XV. 1907 p. 750. 92 The Geology of the Oil-Shale Fields. sliale-measures, and make useful liorizons for the purposes of eorrela- tiou. In writing this paragrapli, we have in mind a case where If) " limestones " were entered in the journal of a bore which, as recorded, was unreadable ; an examination of the cores showed that, with two minor exceptions, only one was a true limestone, and it afforded an invaluable " mark " in reading the sequence proved. In another instance, a fifteen-foot limestone was missed altogether, and although subsequently noticed, the cores were by that time so disturbed that its exact position could not be fixed. The shales found in this bore were well known, but if in addition the depth of the limestone could have been determined, it would have been possible to say whether or not there was a large fault in the vicinity of the bore — a point which still remains in doubt. On the other hand, it is only right to say that on another occasioji a borer recorded " hmestone showing encrinites " in his journal ; his observation was perfectly correct, and was of great value, for these strata are excellent " marks," although extremely rare in the shale-measures. It is at all times desirable that cores should be kept for reference. As an instance, the preservation of the cores of the Duddingston borings gave us the data on which to correlate the Pumpherston Shales in the Lothians, for the Shell Bed is so inconspicuous on the coast section that otherAvise it would probably have been missed, and the proving of this horizon in the Newyearfield bore, near Pumpherston, would have lacked confirmation elsewhere. Much interesting information was also provided by No. 418 bore, at Philps- toun, while No. 2 bore, Craigs, amongst other facts, confirmed the separation of the Barracks and Burdiehouse Limestones — both being cases where the cores had been laid aside in boxes. The Duddingston, Philpstoun and Craigs bores also largely helped to demonstrate that the Barracks Ash was a good " mark " or index horizon. It is almost impossible to say when a bore may not be of value. A new "■ mark " at all times requires ample confirmation before it can be satisfactorily estabUshed as a datum line. Even when the strata are thought to be well known, some new point may often be noticed. For instance, the South Cobbinshaw boring, which determined the position of the Mungle Shell Bed, was put down simply to prove the condition of a shale whose depth was Vv^ell known : the data obtained in this case affected an area 18 miles away, in which the hori;^on of the- strata was entirely doubtful, and which we now know may possibly contain a valuable shale-field. Use of Fossils. — Although palseontological evidence has been emphasised in this memoir, one does not want to give the impression that all fossils are of equal value to the explorer. They are, however, always worth recording, because, as will be shown immediately, the distribution o'' many forms is as yet imperfectly known, and in these cases some may eventually prove of value. Fossils may be classified under three headings, according to their present degree of usefulness — 1. Fishes, plants, entomostraca, gasteropods, such as Platyosto- mella, &c. 2. Non-marine lamelhbranchs or " mussels." 3. Marine shells [Orthoceras, Goniatites, &c.). As regards the first group, whole fishes are so rarely met with in Proving Oil- Shale Strata — Use of Fossils. 93 cores, or for that matter in field sections also, that their full value has not yet been ascertained. Along with the plants, they mav, however, be of use as local guides (e.g., the "fish bed " in the Pum- pherston Curly Shale, and the " fern bed " under the Wee Shale, at Drumshoreland and Pumpherston). The entomostraca range through- out the Oil-Shale Group, and are also of very limited value, as far as our present knowledge goes. The second group, that of the non-marine lamellibranchs {Mya- lina, &c.) are common in the basal part of the Oil-Shale Group but are very rare above the Pumpherston position. They are very fitful and sporadic in their distribution, but have a certain value (see the discussion concerning the Dalmahoy Shale, p. 79) ; the same remark applies to Lingula shells and to the " shrimps." The last group, comprising the marine fossils, is in striking con- trast to the j)receding. To the geologist, they are cpiite as reliable a guide as well-known lithological horizons like the Burdiehouse Limestone or the Houston Goal and Marls. Confirmation of this view is afforded by the behaviour of similar horizons in the Possil or Edge Coal Group of the Carboniferous Limestone Series ; in these strata two marine shell-bands have been noticed in the Glasgow district, and traced continuously round the south side of the Lanark- shire coal-field to Wilsontown — a distance of 40 miles.* At the same time one does not wish to press this matter unduly. Within the Lower Limestone Series these bands are not so constant, and accordingly in the topmost members of the Oil-Shale Group, between the Raeburn Shale and the Cobbinshaw Limestone, where the strata merge into the Lower Limestone Group above, it may be that in the future other shell beds will be discovered that are less widespread than the Mungle and Pumpherston horizons. But it can be asserted with some confidence that the tv/o last-named beds range throughout the shale-fields, are easily recognisable, and that no similar horizon is found in the intervening strata, f These shell-beds also occur in the basal members of the Oil-Shale Group, but they probably lie a long way below the Pumpherston position. (See p. 6.) A list of fossils from the Mungle and Pumpherston Shell Beds, as determined up to the present, is appended. * Others have been traced for very long distances in the Upper Coal-Measures of Scotland (see J. Smith and C. T. Clough, Sum. Prog. Oeol. Survey for 1907, p. 127, &c.). Marine bands have also proved of great value in tlie English coal-fields (see, for example, Walcot Gibson and others in " The North Staffordshire Coal-field " (Mem. Oeol. Survey), 1905, and J. Stobbs, Quart. Journ. Geol. Soc., 1905, vol. Ixi., p. 495). t One exception to this last statement must be made. A bore at Livingston in November lyl2, passed through a marine shell-bed, three inches thick, between the Main and Under Dunnet Shales. This band has not been noticed elsewhere in the Shale-fields, although it may be represented by the Lingula bed found about this position at Cobbinshaw (p. 18). This Dunnet Shell Bed would, therefore, seem to be a purely local one, and in any ease the characters, both of the asso- ciated sediments and of the fossils, are quite sufficient to distinguish this band from those found under the Mungle and Pumpherston Shales. As regards the fossils, crushed fragments of an undetermined Goniatite are common, along with an occasional small Orthoceras, and an abundance of the small lamellibranch Actinnpteria flvctun.ta, which has not yet been recorded from the other two Shell Beds, although common enough in the overlying Lower Limestone Sei'ies. 94 The Geology of the Oil-Shale Fields. FOSSILS FROM iMUNGLE SHELL BED. South Cobbinshaw Bore — Encrinite stems. Productus cf. longispinus, J. Sow. (The above from a half-inch rib in centre of bed). Sangin'nolites variabilis, M'Coy. Edmondia sp. Amculopecten sp. Posidunomya becheri, Bronn. Pf.ychomphalina aif. atomaria, Phil). Bucanopsis sp. nov. (?) Glyphioceras truncatum, Phill. (V) Glyphioceras micronotum, Phill. Stroboceras sp. (?) Orthnceras gesneri, Mart. Entomostraca. [Also a few other species not j'et determined.! FoRDEL Railway Cutting (1^ Miles E. by N. from Tnverkeithing. Edtnondia cf. scalaris, M'Coy. Sanguinoliies cf. V-scrijAus, Hind. Sanguinolites variabilis, M'Coy. Cypricardella sp. nov. Cardiomorpha sp. nov. Posidonomga cf. becheri Bronn. Ptychomphalina aff. atoinaria, Phill. [Same as in Cobbinshaw bore.] Macrochcilina rectilinea, Phill. Bucanopsis sp. nov. [Same as in Cobbinshaw bore.] Euphemus urei, Flem. Tropidocyclus cf. duchasleli, L'Eveille. Actinoceras sowerbyi, M'Coy. Orthoceras cylindraceum, Flem. Orthoceras sulcatum, Flem. Coelonautilus planotcrgatus, M'Coy. Stroboceras sulcatum (''.), J. de C. Sow. Coloceras coyanum, d'Orb. Dinior'phoceras gilbertsoni, Phill. Glyphioceras truncatum, Phill. Glyphioceras micronotum, Phill. Glyphioceras subtruncatum, FoorJ. Entomostraca. PUMPHERSTON SHELL BED. Coast Section. Orthoceras cf. cylindraceum, Flem. Pseudamusium sp. Aviculopecten subconoideus, Eth. Euphemus urei, Flem. (iojiiatite. Entomostraca. Duddingston Borings. Orthoceras sp. Pseudamusium sp. Naiadites sp. Entomostraca. Newyearfield Bore, Li\aNGSTON (No. 25). Orthoceras sp. Pseudamusium sp. Goniatite. Entomostraca. Tealliocaris sp. (from " shrimp " bed below marine band). Conclusion. TJie great majority of the new points noticed in the geological portion of this memoir could not have been made without the gener- ous co-operation of the companies concerned, especially vnt\x regard to the examination of diamond bores. It is hoped that their pre- sentation m the foregoing pages may show that use can be made of data provided in this manner, which is of value to the community in general, without necessarily divulging the nature or value of the minerals in recently proved ground. PART IL METHODS OF WORKING THE OIL-SHALES. i. Search for Shale. By a careful examination of rock exposures, and notably in the beds of rivers, sides of ravines, quarries, and railway cuttings, indications may be found which point to the existence of a seam of shale ; or the shale may be seen cropping out with shaly blaes interposed, and having an inclination ranging from horizontal to perpendicular. Having taken the inclination of the strata, the next step in the search for shale is to sink bore holes to the seam and obtain sample cuttings, whereby the depth of the seam from the surface is ascer- tained, and its thickness and quality at these particular spots. In the progress of the bore, however, wants, faults, slips or troubles may be encountered, and if these are present in the field and are not shown by the bores, all calculations as to the position of the shale will be upset. Heavy expenditure has often been needlessly incurred through insufficient boring. The bore holes should be put down in a straight line to the dip of the strata or at right angles to the " strike," and placed at a reasonable distance from each other. To trace the outcrop of the seam and ascertain its range of extension, a series of shallow bores is put down, and here again one may be misled by finding the shale to dip in the contrary direction to that expected. Should the strata be disturbed, either by faulting or by folding, the closer the bores are to each other the more trustworthy will be the information in regard to the position, dip, &c., of the shale. This also applies to highly inclined strata, as the bore may be placed beyond the outcrop, and so miss the shale altogether. A study of the following sketches (Fig. 24) will show how easy it is to be led astray by evidence from bores, as two of them do not strike the shale at all, while others either pass into it too soon or meet it at an unexpected angle. When any indication of irregu- larity is shown, it is advisable to put down two or three bore holes not far from each other. A difficulty which presents itself to the borer is the distinction between shale and blaes. They are closely associated, and in the early days of the industry it was not uncommon for a borer to allow his chisel to pass through a seam of shale and record it as blaes in his journal ; but, fortunately, this is now of rare occurrence. Simi- larly, we find seams of blaes recorded as shale in old journals ol bores. Borers can tell when they strike shale or blaes by the difference in 06 96 Methods of Working the Oil-Shales. the resistance offered to the chisel, and the rebound of the rods, both indications being quite perceptible to experienced men. The per- cussive method of hand boring is usually carried out in the shale dis- trict, the plant consisting of headgear, rods, chisel. &c. ; but of recent years the diamond bore has been extensively used, and from its revolving action, by means of a steam-engine, a sohd core is obtained which readily shows the character and incHnation of the strata passed through. A " liand rig " diamond boring machine which can bore either horizon- tally or vertically has recently been at work in the shale district, and is giving highly satisfactory results. It is cap- able of boring to a vertical depth of 100 fathoms, produces cores up to 2;|- inches in diameter, and, besides giving the core, does the work in half the time, for the same cost as by the percussive method. Its portabiUty is a favourable feature, and unless for very deep bores it will probably supersede the steam- driven diamond rig, which necessitates a heavier plant, and consequently more expense in shifting from place to place. Cost of Boring. — (a) Percussive Bor- ing. — The prices ruling in the shale district are from 4s. fid. to 5s. 6d. per fathom for the first five fathoms, 9s. Y^//'//^ /^/^/^//f ^ P^^ fathom for the second five fathoms, ^ and so on, increasing by 4s. 6d. per « fathom on the completion of every five 9 fathoms. (6) Rotary Boring. — The cost of this system is about tlie same as that of percussive boring. When a seam of shale has been found by boring operations, and the exact position and depth of outcrop determined, it is necessary, before sinking a mine, to put down a trial shaft for the purpose of making sm-e as to the true gradient at which the shale is lying, and the thickness and quality of the seam. Fig. 25 shows a trial shaft sunk to a seam of shale, with a level cross-cut driven to another seam in close proximity. A hand windlass is used to raise the m.aterial which is filled into buckets suspended by hemp, or small flexible wire ropes. Mode of Access. 97 After sinking to the seam, the custom is to extract from 50 to 100 tons for the purpose of testing the quahty of the shale, and if the test gives a favourable result the mine is opened out as hereafter described. Fig. 25. — Trial Shaft, with a Level Cross-cut. ii. Mode of Access. The mode of access to the seams of the Pumpherston Shales is shown in Fig. 26. There are live seams, dipping from 29° to 38°, Fig. 26. — Mine driven in Oil-shale, at Pumpherston, with Level Cross-cuts. Fig. 27. — Mine driven in folded Oil-shale Strata, Drumshoreland Basin. and the mine is driven in the middle seam — No. 3 — and continued in that seam. The other seams are entered by level cross-cut mines driven from one to another, as shown, and each is worked separately, the cross-cuts serving for purposes of communication and transit. 6* 98 Methods of Working the Oil-Shales. Ventilation is effected by a fan placed at the top of a shallow pit sunk to one of the seams. Fig. 27 shows three seams of shale, worked by the Pumpherston Oil Company in the Drumshoreland Basin, cropping out at the surface in a vertical position and gradually taking a synclinal form, one side being vertical, the other rising towards the outcrop at an inclination of 2\°. These are entered by a mine driven in the metals at an inclination so as to reach the bottom of the fold, the mine passing through the several seams, which are entered by breaking levels away at suitable intervals. At the other side of the basin these seams are entered by level cross-cut mines, and are " won out " by driving headings to the out- crop, the shale being lowered by self-acting inclines, thence taken by pony haulage to the inclined shaft. Two pits, one on each side of the mine, are sunk to Nos. 2 and 3 seams to give ventilation, and stone headings connecting the bottom of these with the workings are used as airways. Another series of oil-shales in the same basin, known as the Mid- FiG. 28. — Vertical Shaft sunk in Oil-shales, Mid-Calder. Mine Driving. 99 Calder Shales, is shown in Fig. 28, in which there are nine seams, ranging in thickness from 18 inches to 9i feet, and the mode of access is by a vertical shaft, that now passes through them all, but was originally sunk to the higher seams and continued to the others at later periods. For a short distance from both sides of the shaft the seams are flat, then gradually dip as shown in section (Fig. 28). The inclination in these workings is very irregular, varying from 28° to nearly flat, and the section given is probably the best that can be obtained. The shale is taken from the dip workings by main rope haulage. No. 5 was the first seam to be worked, those' above it being entered by cross-cuts off the level portion of that seam. (Fig. 28.) iii. Mine Driving. Having at length chosen the most suitable site for entering the field and obtaining the shale, operations are begun by removing the soil, which is dug out to the required depth and gradient. Brick walls are then built on both sides, with an inchnation corresponding to the floor of the excavation, and are spanned by a brick arch which covers the whole, giving it the appearance of an inclined tunnel. The entrance of the mine being now formed, sinking to or in the seam is begun. The usual dimensions of a mine, or inclined shaft, are : — width, 10 to 12 feet, and height, 6 to 8 feet. Should the sides and roof prove to be of a soft natiu-e, as is generally the case with shale at the crop, the brick walls are continued downwards until harder strata are reached, larch crowns, placed close to each other, being stretched from wall to wall to support the roof. But where the shale is hard and the roof good, .side walling is not necessary, and a less costly method of timbering is adopted. In mine driving it is the usual practice to leave a portion of the seam on the roof, and, in such cases, larch crowns fixed at places according to discretion are sufficient to maintain it. Given a fairly good roof, free from fissm-es or cracks, the distance between the crowns may be from 2 to 3 feet. Both sides of the mine are " needled " to a depth of 6 inches to receive the crowns, but whatever system is adopted the timbering is continued with the sinking of the mine. " Centre-propping " is adopted in some mines. It divides the mine into two unequal parts, and gives better support to the roof. The smaller division has a width of 3 feet 6 inches, and can be used for haulage ropes and water-pipes, while the larger is for the winding. The centre props are of fir, set every 3 to 4 feet, and fixed to runners which have been placed against the crowns in a longitudinal direction, care being taken to have the props in such a position that they may not be thrust out when the superincumbent weight rests on them. Fig. 29 shows the method of timbering the roof and of centre-propping. As the driving of the mine proceeds, provision will require to be made for another outlet, which is obtained by driving a level in the shale, at a safe distance from the surface, for about 80 feet. A head- ing is then formed in the same direction as the mine, and driven to the surface, where a brick-walled exit may also be erected. In- stead of driving the outlet to the surface a vertical shaft may be sunk to meet the heading. During the progress of sinking, levels are broken away in the 1(X) Methods of Working the OU-Slmles. seam at regular distances and driven so as to get communication with, and drive headings to form, the outlet mine. The headings are driven in the same direction as the sinking mine, to the levels above, until they connect with the outlet mine or shaft, the process being commonly termed "turning the stoops." The outlet mine is then used for winding the shale ; the other is kept for sinking Level Driving. ■ 101 purposes, and is now known as the sinking mine, thus winding and sinking can go on simultaneously. Should a large daily output of shale be required, sinking operations may be continued until a depth has been reached sufficient to meet the demand for some years, and winding can then be carried on regularly at both inclines. The driving of a highly inchned mine is more difficult than driving a level or upset, this being chiefly due to the awkward position in which the men have to work. The tools used and the method of excavating the shale by gunpowder are the same in both cases. Ventilation is at first effected by air-pipes, fixed on the sides of the mine from sinking-face to surface, where they are connected to a small temporary fan driven by steam. When the outlet shaft haj been made, and natural ventilation takes place, the temporary fan is discarded, the air being directed in its passage by means of bratticing so as to travel round the sinking-face. Steam-pipes which are led down to the sinking-pump help the ventilation ; but these are considered only temporary expedients until the permanent fan has been erected. The hutches containing the shale are either hauled direct to the surface or conveyed there by sinking-carriage. This carriage is used where the seam is lying at a steep angle, and is preferable to hutches on account of the greater safety to the men working at the face, as it is seldom derailed, and the danger of accident by pieces of shale falling from the hutches and running down the incline is almost entirely prevented. The carriage has two decks, the higher or top one being for the hutch, and the lower serving as a platform on which to throw the shale for filling the hutch. During sinking, the water is taken away from the face by pumps, various types and designs of which are used. A small " sinking " pump, which can be moved forward and connected easily as the sinking proceeds, is used at the face, and when it has reached the distance — i.e. vertical height — at which it can throw water to the surface, a lodgment or " sump " is formed in the side of the mine. The sinking-pump now delivers into the lodgment, and another pump is put down at that point to deliver the water at the surface. This is repeated as the mine proceeds, the water being delivered at the surface in lifts or stages. , iv. Level Driving. Level driving is carried on by hand labour with the aid of the hand-boring m.achine. It is important that the level course be main- tained, as, if neglected, it will probably mean the curtailment of the size of the pillars or stoops caused by the convergence of the levels. When such a contingency arises, bearings are taken so that the con- vergence may be avoided ; but in some cases irregularities appear in the seam which would eventually run one level into another, and one has to be stopped so that the stoop may be left the requisite size. Before beginning to drive a level, the miner makes an examination of the " face " and decides on the portion of the seam likely to make the best holing-bed, off which to blow the shale freely ; but he will be guided as to the best position in which to place the holes when he has seen the effect of a few shots, the natural planes of division and joints being noted so as to obtain from them the greatest possible 7 102 Methods of Working the Oil-Shales. advantage. The number, depth, and direction of the holes depend upon the condition of the bed and the skill of the miner. In Fit's. 30, 31, 32, 33 the hohng is shown about eighteen inches from the pavement. Here a series of holes, usually four or five in number, termed "holing" or "Yankee" holes, are bored at intervals across the width of the place. The seam is worked in lifts or stages. Owing to the character of the shale smooth beds are often met with, and when these are " jointed " the shots do not have the same i- ^ >iM ^^"^^^^ -^^-=- Fio. 30. — Face of Level, showing the various kinds of Holes. Fig. 31. — Longitudinal Section through Holes. effect and more are required to do the work. The series of holers are bored 3J feet deep, with sufficient dip to reach the bed off which the shale is to be blown. In the plan of " holers " (Fig. 32) holes No. 1 and 2 are inclined towards each other, and one of these, receiving a heavier charge than the other, is termed a " burster." After the holing shots have been fired two holes are bored, one in each corner of the place, to bring down the next lift of the seam. Fio. 32.— Plan of " Holers." Fig. 33.— Plan of " Brairdars." These shots, known as " brairders," are drilled about 2 feet from the sides of the level and are driven about 2 feet deep, with sufficient angle to reach within twelve inches of the sides. When they have been fired, another series of " holers " and " brairders " are carried through until a depth of about 5 feet is reached. An excavation about 5 feet in depth by 3 in height having now been made, attention is turned towards removing the 5 feet of shale still remaining on the top. It is found necessary, however, to remove it in two lifts, the resistance being too great to permit of it being done in one operation. Drills and Boring. 103 ff there is too much resistance tjie hole will act like a cannon, blowing out the stemming and producing what is known as a " blown-out " shot. Shots of this kind are of no service, and care ought to be taken to prevent loss of explosives through such a cause. The five feet portion is divided, and two shots, known as " mids," are placed in nearly the same direction as the " brairders," but instead of both holes being inchned towards the sides, only one is in that position, the other being put in straight. These holes are drilled 3-| feet deep, both being placed about 2 feet from the sides of the level. The last or top portion of the shale to be removed — 2| feet high — is technically termed " tops," and also requires two shots to remove it, placed in practically the same position and direction as the " mids," The quantity of gunpowder used in each of the various holes, drilled in level driving, averages — Holers, "Burster" . . . . . 2to2ilb, „ "Ordinary" . . . . 1? „ Brairders . . . , . . IJ j> Mds and Tops . . . . . 2 „ In the series of hohng shots, the " burster " is fired and its effect noted before the ordinary holers are bored, the work done by the former guiding the miner as to the number and position of the latter ; but as shale seams requiring to be wholly blasted are not all alike, the number of holes and quantity of gunpowder to be used must depend upon the prevailing conditions. Holes are bored by the barrel boring machine. A pit-prop, generally known as a boring-tree, is fixed in position by " stamping " a hole in the bench and roof, and to this prop the machine is fixed at the barrel-end by a pointed piece of iron, which is sunk into the prop by two or three turns of the barrel. The other end is supported by the drill. Boring is now started by a backward and forward movement of the ratchet handle, and is continued until the screw is extended to its full length, when the barrel is unscrewed by hand and the drill taken out and a longer one put in its place. This process is repeated until the hole has been bored to the required depth. Of recent date electric- driven drills for boring the shot holes, by John Davis & Son (Derby) Ltd., have been introduced in oil-shale mines where the prevaihng circumstances have proved suitable for their adoption. In oil-shale mines of an easy gradient the drill is very successfully worked, as it can be readily moved from place to place ; consequently in such mines it is of considerably m.ore benefit than in those where the shales lie at a steep angle. The drill is of the rotary pattern, and is driven by a 3 h.p. continuous current motor, of the 4 pole series-wound type, with two field coils. The drills, in addition to being driven by continuous current motors, are made with 3-phase alternating current motors. The armatm'e spindle is hollow, the drill feed screw passing through it, and by this means a well balanced drill is provided. The drill is shown in Fig. 34, and arranged so as to permit of holes being bored at any angle. It can be fitted with various feeds, according to the character of the mineral to be. dealt with, both as to speed of rotation and rate of progression, but the feed found to be most suitable in the oil-shale mines is 106 R.P.M. 104 Methods of Working the Oil-Shales. and six threads per inch, giving a forward feed of 1 7 feet 9 inches per minute. The supporting frame, which is jammed between the roof and pavement by means of a strong screw, is constructed of two " channel " bars with cast-steel top and bottom yokes. The machine is sub- stantially constructed, and its weight, including a continuous or alter- nating motor is somewhat under 300 lb. The drilling of the holes is generally performed on back-shift commencing at '3 o'clock and terminating at 10 o'clock. In one mine, belon;iing to Messrs. Young's Paraffin Light and Mineral Oil Co., Ltd., there are three machines at work, and each is operated by two men and a boy. On an average 75 holes — measuring 3 feet in depth and Fig. 34.— Electric Drill. 21 inches diameter — are drilled per shift. The writer, when visiting the mine, saw 8 holes bored in 17 minutes, but this time included the removal of the machine from one place to another. The actual time taken to bore a 3-foot hole 2^ inches diameter is 1 minute 30 seconds.. For the purpose of conveying the drilling machine from place to place, a hght truck mounted on wheels suited to the gauge of the hutch railway is used. Following the men who operate the machine are the shot firers, two men being employed to stem and fire the shots. Some seams have a bed of " daugh " or other soft material em- bedded in the shale, or at the bottom of the seam, and when this occurs the hohng can be done by the miner's pick, thereby saving the laborious process of boring. Less gunpowder, is required in seams which have this holing. Boring and Blasting. 105 Driving " Ends " or Upsets. — The " ends," or upsets, leaving the levels at regular intervals, are driven by the same method as the latter. The miner, however, has not the same freedom in working the upset, on account of the difficulty in maintaining his footing on the incHne; but, in order to facilitate his movements, pit props are laid across the pavement at regular distances apart and fixed to the sides of the place. Stamp holes are also made in the pavement to give better footing, and ropes and chains afford considerable assistance as he ascends or descends the upset. The boring operations at face are facihtated by the erection of a simple " scaffold," consisting of two props placed vertically, with two or three laid horizontally against them, thus making a platform from which the miner can work freely. The inclination of the upsets causes the shale, when blasted, to run to the bottom, where it is placed in hutches, which are pushed or drawn out to the inclined shaft for conveyance to the surface. Driving Cross-cuts. — These are driven to obtain seams in close proximity to each other. They traverse the different beds, and are wholly driven by the use of the boring machine and explosives, their average width and height being about 6 feet. Labour Notes. — The number of men usually employed at driving a level is two or three — either one or two working at the face, and one placing the shale in hutches and " drawing " it to the inclined shaft. These men are known as contractors or placemen, shift face- men, and drawers respectively. The contractor agrees to drive the level at a price, and is held responsible by the management for working it safely and properly. He pays the wages of all shift facemen and drawers, pays for all explosives, and supplies and maintains all necessary tools. The rate or speed at which a level is driven depends chiefly upon the nature of the seams, but is also affected by other conditions. In a fairly good seam with a level 12 feet wide and 8 feet high, 2 feet per day or 12 feet per week would be considered a good average distance, and by calculation the daily number of tons of shale won, assuming 20 cubic feet as being equal to one ton, would be ^^^^|^, or 9 tons 12 cwt. This would give an output of three tons per day for each of three men, and, while that figure is often exceeded, it may be taken as the average " darg " in the shale workings. v. Blasting and Explosives. Cleaning Shot Holes. — The shot holes having been bored to the requisite distance, the miner must clean them out before inserting the explosive. For this purpose he uses a tool termed a scraper or cleaner (Fig. od) which is made entirely of copper, and is about 4 feet long and /v of an inch in diameter. One of the ends is flattened and bent over at right angles to the rod, giving it the appearance of a button with a diameter slightly less than that of the shot hole. The " button " end is put into the hole, and, when withdrawn, brings with it a portion of the dust, the process being repeated until the hole is quite clean and ready for the explosive charge. Cartridges. — These are made of strong paper, and vary in length 106 Methods of Working the Oil-Shales. according to the amount of explosive required. Their diameter is slightly less than that of the shot hole, so that they may be easily inserted, as the Coal Mines Regulation Act of 1887 prohibits an TO Fig. 35. — Cleaner {it) ; Stemiiier (/>). explosive to be forcibly pressed into a hole of insufficient size. This Act also prohibits the taking of explosives into a mine or pit unless in cartridges placed in a secure case or canister containing not more than 5 lb. Fig. 36. — Cartridge in position in Shot hole. Charging and Firing. — The miner having determined the size of cartridge to be used, inserts a length of fuse into one end, and pushes the cartridge gently to the back of the hole by means of a " stemmer " (Fig. 35), the fuse being of sufficient length to project 5 or 6 inches beyond the mouth of the hole. The " stemming," which is com- posed of the broken material and dust got from the hole, mixed with a httle water to bind them together, is then rammed with the " stemmer " against the cartridge until the hole is filled to the mouth. The charge being now ready for firing, the fuse is lighted with the lamp used by the miners, who retire to a safe place until they hear the shot go off. Fig. 36 shows the cartridge in position and ready to be lit. The fuse burns at the rate of about 30 inches per minute, giving ample time for the men to place themselves beyond reach of the shot. It has a central core of gunpowder surrounded by cords of cotton or flax, which have an outer covering of tarred tape. For blasting in wet places the fuse may have an outer covering of two coils of tape with a layer of varnish between, or, as a further preventive against damp- ness, these can be covered with gutta-percha. Accidents in Blasting. 107 Accidents in Blasting. — Accidents occur from many causes, a few of which may be given. 1. From break in continuity of fuse, dampness of fuse, or damage to fuse while charging shot hole. 2. By men returning too quickly when a shot hangs fire. 3. Attempting to hght more than two shots at a time. The number of accidents from the first cause is small, and in nearly every instance can be traced to the miner having retiuned to his working-place before the time stipulated in the Act. The second cause has the same ultimate effect as the first, but the number of accidents, fatal and otherwise, due to the carelessness or foolhardiness of the miners, has been much larger than should have occurred with ordinary precautions. The third cause was also a source of deep concern to those engaged in shale mining, as the men were not re- stricted to a given number of shots to be fired in any one place at any one time. Hence they frequently proceeded to light more than two shots, with the result that many serious accidents occurred, probably caused by the miner returning to the face in the belief that all the shots had gone off, while one failing to hght properly, and exploding as he went forward, caused serious and, in some cases, fatal injury. With the view of doing everything possible to reduce these acci- dents to a minimum, Mr. Robert M'Laren, H.M. Inspector of Mines, East of Scotland District, had a conference with the mining managers of the shale industry about seven years ago, and it was then agreed to put into force the following additional special rule 1 A. : — " Shot Firing. — Not more than two shots shall be charged and fired in any working-place at any one time, except in upsets rising more than 1 in 3|, where foiu* shots may be charged and fired, provided that one person lights two shots only. Should the fuse of any shot mis-light, the person or persons firing shall leave the place, and shall not return for the period of 30 minutes." The oil-shale measures on the whole being very steep a certain amount of danger was attached to men going back to examine their upsets amongst the smoke after firing, and to overcome this the angle of 1 in 3| was stipulated, as it was considered to be pretty flat and, consequently, not so dangerous. The adoption of this rule has had a marked effect, accidents from shot firing being now of rare occurrence. It is worthy of note that miners are not allowed by the Act to have a naked lamp on their cap while placing fuse in cartridge. On the whole, it may be fairly stated that, considering the large quantity of gunpowder used in shale mining, the accidents from blasting are comparatively few. Explosives Used. — Except in special circumstances, gunpowder is the explosive used for blasting shale, its slow combustion causing a rendiug action and producing less small debris than any of the other known agents. The reduction of the quantity of small shale to the minimum is of great importance to the industry, on account of its packing closely in the retorts and preventing the heat iiom carrying out the destructive distillation. Gelignite is used in wet places, where gunpowder is not suitable, and in crossing hard beds of rock, but in ordinary working it shatters the rock too much. Ordinary mining gunpowder is of coarse grain, higld\' glazed. 108 Methods of Worhing the Oil-Shales. and the usual composition is 75 parts saltpetre, 15 parts carbon, and 10 parts sulphiu". It is stored in magazines convenient to the various pits or mines, and given out in the quantities required by the miners employed on the different shifts. Quantity and Cost of Gimpowder and Fuse. — The quantity of gun- powder used varies according to the quahty and position of the shale. The undernoted Table may be taken as an average of what is required in a blasting seam : — Sliots fired per Day. 250 Shale Gunjiowder Got. Used. Cost of Gunpowder. Cost of Fuse per Ton of Shale. Total Cost of Explosives per Ton of Shale. P«Mao.;P-S Tous. Lb. 475 375 7-31d. 1 3-16d. •27d. 3-43d. vi. Methods of Working. There are two well-known methods of working oil -shale — (1) " Stoop and Room," and (2) " Longwall," each having its own ad- vantages, according to circumstances. The shale seams vary from four to ten feet in thickness, say seven feet as an average, and on the whole are comparatively free from blaes. J'b=JLJi VH i L E_VEL Fig. 37.— Stoop and Room Method of Working Oil-shale. fakes, and ribs of unproductive rock. With a thickness of seven feet, experience shows that the method best adapted for the efficient working of the shale is stoop and room ; but in the case of two seams of shale, separated by a bed of fakes, or other foreign material, of sufficient thickness for packing, the longwall method may prove to be more suitable. S>toof and Room. — This method is more generally used through- Stoof and Room Working. 109 out the shale district than the other, and will be first described. Its chief characteristics are (1) the " whole " or first working, and (2) the " broken " or second working. (1) The " whole " working consists of a series of excavations made in the shale, whereby it is divided into rectangular blocks or pillars (Fig. 37). These excavations are called rooms, one set being driven at right angles to the dip of the shale and at regular distances from one another and commonly called levels ; another set driven to the rise of these levels and at right angles to them, being commonly Fig. 38. 'Pl*it,m Off Stoitj^. -Plan and Section of highly inclined Stoops. known as " ends " or upsets. The latter are broken off the levels at regular intervals and driven upwards to meet the levels above. The nature of the roof and pavement will determine the width to which the rooms may be driven. In the event of a bad roof, with rooms driven 12 feet wide, falls would be more frequent, and more timber would be used than in rooms driven 10 feet wide ; therefore, it would be cheaper to curtail the width when the roof is not good. The width of levels and ends in the shale workings is JO to 12 feet. As the pillars are for the purpose of supporting the superincumbent strata, their size calls for special attention. It has already been stated that with increased depth there will be increased pressure, and to provide for this contingency stoops of the requisite size should 110 Methods of Working the Oil-Shales. be formed. In highly inclined workings the stoops, or pillars, are made longer to the rise than at right angles to the dip, because the inchnation of the seam decreases the actual supporting area of the stoops, and inchned stoops under the great weight of the overlying rocks have a marked tendency to shp. Fig. 38 is a plan and section of highly inclined stoops. No rule can be given for determining the size of stoops ; in form- ing them one must be guided by prevaiUng circumstances. These are the condition of the roof and pavement, and the inclination and depth of the seam. It is evident, however, that by leaving large stoops, the ventilation of the ends will require special attention. This will be dealt with under the heading of Ventilation. Fig. 39. — Creep of the Strata in highly inclined Wne. Of all the difficulties associated with mining, whether the mineral be coal or shale, " creep " is about the most formidable, as when once started it is very improbable that anything can be done to check its destructive effects. The first indication of " creep " is given by the heaving or lifting up of the pavement of the rooms, causing the timber to bend and break and the rails of the hutch roadway to become twisted and displaced. It is primarily caused by leaving small stoops, which are unable to withstand tlie pressure they have to bear. A\'Tien the weight of the overlying strata bears heavily upon these weak supports, they begin to sink, and in doing so bring down the roof, force up the pavement, and fill the rooms. A secondary cause of " creep " is found in a soft and yielding pavement. Stoojj and Room Working. Ill Fig. 39 shows a " creep " in its earlier (a) and in its final stages (6) in a highly inclined mine. (2) Broken Working. — After the first or " whole " working has reached the boundary of the shale -field, or when sufl&cient ground has been opened out by that system, the " broken " working, or stooping, is commenced. When stoops are kept standing too long they begin to show signs of the effect of the extra weight they have to support, and ultimately collapse; therefore the system of stooping a portion of the field as the " whole " workings proceed — always keeping a safe distance from these workings — is generally adopted. In seams where the shale is highly inclined stooping should be begun as quickly as possible, in order to relieve the weight on the stoops that are left to support the inclined shaft and to avoid a " creep." There being considerably more danger from falls of the roof to the men employed in " broken " than in " whole " workings, it is important that the timbering be skilfully done. Accidents sometimes occur, and shale is often lost, by carelessness on the part of the miner in not having his place securely timbered. The extraction of the stoops must be carried out in a systematic manner, care being taken not to have one lagging too far behind another. From Fig. 37, it will be seen that the operations are carried on with the stoops in advance of each other, thus forming a diagonal line. To maintain this line the places should be equally manned and regularly worked. Methods of Removing the Stoops. — One method of removing stoops is to take a series of slices or " lifts " off them, the slices varying in width from 12 to 15 feet. Fig. 40a shows a 15-foot slice in process a^sa^ J li_, Ji L ^ a i W^ l[> . 41-9 j> . 33-3 4-8 >> over wooden tubes of the same section, each 12 feet long, and jointed with spigot and faucet joints. One side of each tube was hinged, and shelves were fitted at intervals on the other side. The total length of the tubes was 48 feet. Pieces of cotton-wool were fixed at intervals of 18 inches on the edges of the shelving to indicate to what extent the flame travelled in the tubes from the diaphragm. The gas used for the explosions was taken from the main Broxburn Works supply, and its composition was as under — Oxygen Olefines Hydrogen Marsh Gas Nitrogen lOO'O By experiment it was found that mixtiu-es of 10 to 12-| per cent, of gas gave a violent explosion, and this mixtm'e was used throughout the tests. The Experiments. — The first three experiments consisted of an explosive mixture of 12J per cent, of gas and 87i per cent, of air. This was fired, and gave an average length of flame of 15 feet, which was measiu-ed by means of little pieces of cotton-v/ool moistened with naphtha and hung at short intervals in the tubes. Shale-mine dust was thereafter spread along 24 feet of the tubes, and out of six tests the flame did not travel more than 12 feet. In order to ascertain the effect of coal dust in the apparatus, under exactly similar conditions, the tubes were swept clean, and a quantity of coal-dust was spread along the entire length of 48 feet. On firing the mixture the flame shot out a distance of 5 feet from the end of the tubes. These experiments proved conclusively that not only was shale dust non-explosive, but it had a tendency to retard the flame. Experiments were also carried out on the zone system, i.e., shale- dust was laid alternately with coal-dust in zones. These clearly demonstrated that shale-dust mixed in certain proportions with coal-dust destroys the capacity of the latter for propagating an ex- plosion. The experiments revealed the fact that shale dust was not inflam- mable in the presence of a fire-damp explosion, but would act rather as a retarder to the progress of the flame. Further evidence of this has been clearly demonstrated (in the case of explosions) of fire-damp in shale mines. The following is a detailed table of the experiments : — [Table 122 Methods of Working the Oil-Shales. (I) JtnkO, 1909. — Weather: dry; barometer: 29-87; tlicrinoineter : dry bulb, 66"° ; wet bulb, 59°. No. of Test. 10 11 12 13 Explosive Mixture. Gas. Per cent. 12 12i m 12i r2i 12 12 10 10 10 10 10 Time for Diffusion. Minutes. 3 3 3 3 Nature of Dust. None None None Sliale-niiue dust.. Do. Do. Do. Do. Do. Roman Camp shale dust Do. Coal -Dust, 15 pounds Coal -Dust, 20 pounds 1 1 Lengrtb | of Flame. Ft. Ins. 15 16 6 13 6 12 12 12 12 13 6 13 6 36 55 Remarks. 14 po.niHs of dust were spread along 24 ft. of tubes. Failed to explode properly, owing probably to the high temperature of the explosion chamber. Exploded satisfactorily. 21 p( unds of dust were spread over 24 ft. of till es. (Quantity of gas redu'od to compensate for increased temperature, 86°.) 20 pounds of Roman Camp shale-dust used. Coal-dust obtained from coal emptieil at Stewartfield was spread along 48 ft. of tubes. (2) July 5, 1909. — Weather': dry; barometer : 29-7 ; thermometer : dry bulb, 63° ; wet bulb, 57°. 14 10 15 10 16 10 17 10 18 10 19 10 20 21 22 23 24 25 10 10 10 10 10 10 2^ ' None 3 n 3 3 2i 2h None 21 pounds shale- dust Pumphei stou shale-dust Do. Coal du.^t from Earnoek Col- liery Coal- ami shale- dust in zones Do. Shale-dust on top of coal-dust Do. 2i ' Mixed dusts 2i Do. 20 6 16 6 16 6 16 6 i 16 20 6 22 39 24 24 20 6 13 6 Shook the dust out of the seams in the tube left after test No. 13. Very sharp explosion. This dust was brought from Pumpherston. Good explosion. Do. do. 20 pounds of this dust were spread, but it was much too coarse, and could not be called "dust." 12 feet of coal-dust were laid next the chamber, then 12 feet of shale-du.st, and then another 12 feet of coal-dust. 12 feet of coal-dust were laid, then 6 feet of shale- dust, and then 18 feet of coal-dust. The shale-dust was spread on top of the coal-dust in equal proportions. The proportion of shale- dust was increased to 125 i)er cent. The propoition of shale- dust was increased to 150 per cent. Ventilation of Workings. 123 Ventilation of WorJcings. — In order that the poisonous and in- flammable gases, given ofE by the strata and produced ])y blasting operations, may be well diluted and rendered harmless, it is abso- lutely necessary that fresh air be freely introduced into the mine, and for this the law makes due provision. There must be at least two openings into every mine, one to act as an inlet, the other as an outlet. Ventilation by artificial means is universally adopted. The principal machine in use for producing circulation of air is a fan, which may be of the Guibal, Waddel, Capell, or other type. The Gruibal (Fig. 53) is most commonly used in the shale districts, and gives satisfactory results. It is simple in construction, requires little repair, and has a high efficiency. This type, like the Waddel, being slow speed, is driven direct from the engine. Fig. 53. — Fan used in Ventilating Shale Mines. At the Duddingston mine of the Oakbank Oil Company a Capell fan 8 feet in diameter by 3i feet wide, having a guaranteed capacity of 80,000 cubic feet of air per minute, with a 3-inch water gauge, is used for ventilating the workings. An electric motor, with reduction gear, supplies the power for working this fan, which is giving satis- faction. If the fan used be of the exhaust type, it is placed at the outlet shaft, and draws the foul air from the workings. The fresh air enters by the inlet shaft, and is conducted through the workings by means of doors, stoppings, and screen or brattice cloth which has been rendered non-inflammable by a special chemical treatment. For the erection of screen cloth, light props are put up 9 feet apart, and to these are nailed the brattice boards, which are 18 feet by 6i inches by | of an inch thick, the cloth in turn being fixed by nails to the boards. Two or three boards in depth are necessary to carry the cloth, and they are usually fixed close to roof and pavement, wherever possible, so that there may not be open spaces for the air to escape. Should it not be possible to erect the boards so as to get the cloth to cover the whole space, .small pieces of cloth or any 124 Methods of Working the Oil-Shales. suitable material are used to cover up the openings. Fig. 54 shows the method of erecting the cloth. In mines where the seams of shale require to be wholly won by blasting, the brattice cloth cannot be erected so close to the level face as in the case of a seam holed with the pick, on account of the debris from the shots blowing it down. ,' ^^l^^^:^|fafejrtf6^Ji=5: ''Mj;^^V^^ii^^X^=i^'^-i^^^^i^:^s y Fig. 54.— (A) Brattice Boards ; (r) Brattice Cloth ; (j') 1'>"1'^- The rule is to have the cloth fixed as close and tight as possible to prevent leakage, and to have a plentiful supply of air to carry of! the smoke produced by the firing of shots. In steep workings where blasting is carried on the ventilating of the upsets cannot be done properly with this cloth, especially if the upsets are long, as it is difficult to get fresh air to travel uphill, and the blasting opera- tions make it almost impossible to keep the cloth tight. To over- come this difficulty, a small hand fan, worked by a boy, is used. Fig. 55.— («) Hand Fan ; {b, r, d) Woodeu Rliones. Fig. 55a shows a sketch of this fan. The fan is fixed to a platform made of wooden sleepers, and is kept v/orking by the boy turning a handle. It is of the blow type, and is placed at the rise side of the level in the intake airway, the brattice cloth being led past and turned up the end for 4 or 5 feet. Wooden rhones 11 feet long by 9 Ventilation of Workings. 125 inches broad by 9 inches deep, made of wood | of an inch thick, having socket at one end and slight taper at the other (Fig. 556), are used to carry the air the required distance up the upset. Wooden bends (Fig. 55c) connect the fan to the rhones. The method of fixing the rhones is as follows : — A length of rhone is attached to the connecting piece of the fan (Fig. 55(Z), and to this the bend and more lengths of rhone are joined. In the case of a loose joint, screen cloth is used as packing to prevent leakage of the air. The rhones are carried on brackets which are fixed at one end to vertical props 9 feet apart and at the other to the stoop side (Fig. 56). Fig. 57 shows a section of an upset and rhones in position. "i^TS^S^^^ Fio. 56. — Method of fixing Fig. 57. — Upset and Rhones in position. Rhunes in XJpset. Before blasting, a rhone is usually removed to prevent it being broken, but after the shot or shots have been fired, this rhone is rcfixcd and the fan set in motion to remove the smoke and gases. Letter ventilation is got by the use of the hand fan, which is also found to be most useful in removing accumulations of inflam- mable gases. Iron pipes are sometimes used instead of rhones to convey the air from hand fan when a heading is being driven. These headings are longer than the usual upsets, and the pipes, which are about 18 inches in diameter, are not so liable to damage, and give better joints, than the rhones. Trap-doors (Fig. 58) are placed in every level throughout the workings, generally at sufficient distance from the incHned shaft to allow of a good-sized " lye " or siding for hutches. These doors are made of wood, 4 feet square by 1^- inches thick, and are usually supported by a brick wall 9 inches thick, in which standards and 126 Methods of Working the Oil-Shales. lintel are fixed. They are hung by means of hinges, and have sufficient " lean to " at top to close themselves. On one side is fixed an iron hoop with a piece of wood between (Fig. 58), and the hutch on being pushed forward strikes this buffer and forces the door open without damaging it. In stoop and room workings a large amount of bratticing is re- quired, as the air would take the shortest route to the return airway if not conducted by some system or other. To overcome this diffi- culty, brattice cloth is fixed to convey the air to tlie working faces, which is erected at one side of the road — the rise side if working be inclined — about 4 feet from the stoop side. Should the air be travel- hng downhill, the space enclosed by the bratticing will be the intake, but if taken down the inclined shaft and split at the bottom, the roads. iLcTt cj}T7^tLp-cio-oin aui*^jBvK^fy}ei Fig. 58. — Trap-door. or space outside, serve as the intake and the enclosed space as the return airway. Fig. 59 shows the usual arrangement of ventilating the rooms. This plan shows the air brought down the inclined shaft and spht at the bottom, then led to face by use of brattice as indicated by arrows, the roads being the intake and the brattice the return airway. To prevent the air from going back to the shaft, stoppings, S, made of brattice cloth and boards, are placed at the top of the ends. The trap-doors, D, built in the level roads, and hanging brattice cloth made fast at top, but left loose at bottom, so that it may be easily put aside to allow passage of men or hutches, also serve to convey the air throughout the worlcings. Stoppings built of brick are erected when it is decided to shut off a portion of the workings. Shale seams being of good thickness, the airways throughout the workings are of comparatively large area, which contributes materially to the maintenance of good ventilation. The ventilation of longwall workings, as shown in Fig. 41, is a more simple operation than the stoop and room system just described, there being less obstruction to the currents of air. Bratticing is Pumping^ Water. 127 not required to nearly the same extent, therefore the ventilation of longwall is considerably cheaper than that of stoop and room. Fia. 69. — Ventilation of Stoop and Room Workings. ix. Pumping Water. Shale-bearing strata being almost impervious, the quantity of water met with in ordinary working is not great, and the larger pro- portion is probably due to fissures and faults through which it has found its way from the surface. When stooping, the quantity is increased, in many cases to a large extent, by the ground at surface being broken and the whole rainfall on the damaged area finding its way into the workings. Appliances for Dealing ivith Water. — The workings are kept free from water by the use of pumps of various types and designs, which force it to the surface. The pumps commonly used are the plunger, or ram pump, and the piston pump ; and the steam-engine supplying the power may be either on the surface or underground. Pumping with rods gives a very low efficiency, and is being gradually super- seded by more modern apphances. Direct Acting Pumps. — These consist of a steam cylinder and water barrel or cylinder, attached by tie rods and fixed to the same bedplate. They are connected by a through-going piston rod having the piston for steam cylinder on one end and the plunger or ram for the water barrel on the other, and are usually of the double-acting type. A large number are now in use, dealing with quantities of water up to 390 gallons per minute, and against a head of 540 feet. Other Types. — Hydraulic pumps of Moore's or Brown's design, driven by hydraulic pressure from pumping engine on sm'face, are at work in the shale mines. Electric pumps have also been introduced in recent years. They take up more space than the ordinary steam types, and special chambers, with brick walls and roof girders, have to be form.ed to receive them. This type is finding favour in the shale district, and 128 Methods of Working the Oil-Shales. may eventually supersede tlie others. Its chief advantages are the traiismission of power through long distances from central stations, high efficiency, and economy in working. Analysis of Water. — The water pumped from the workings is suitable for steam-boilers in the majority of cases. The following is the analysis of a typical water, from shale mines, which is used for steam purposes : — Grains per Gallon. Carbonate of Lime and Magnesia . . . 1581 Carbonate of Soda ..... 5'68 Common Salt ..... 7"33 Sulphate of Soda ..... 26-49 55-31 X. Underground Haulage. The shale produced at the working face is placed in hutches which are taken to the " lye " or terminus by men termed drawers, by horse haulage, or by rope or chain haulage, and while in transit, may have to be put down a self-acting incline. The hutches are either made of iron or wood, and have a carrying capacity of from 10 to 12 cwt. of shale. The weight of an em_pty hutch is from 4 to 5 cwt. Railways for Hutches. — The railways over which the hutches pass are of various weights and sections. In the side roads leading to the faces the weight is 12 to 14 lb. per yard, but on cut chain braes, (look haulages, and horse roads a heavier rail — 20 to 24 lb. — is used. Rails are usually delivered in lengths at or between 12 and 18 feet, the short lengths being preferred for the light section used at faces, and the others for the heavier rails on the principal roads. The gauge of railway is from 23 to 30 inches. Drawing Shale. — By far the largest proportion of the shale is taken from the working faces to the " lye " at inclined shaft by manual labour. A double line of rails is laid for some distance back from the inchned shaft, and this forms the " lye " for full and empty hutches. The drawer takes out a full hutch from the face to the " lye," returns with an empty one, which he fills, repeating the pro- cess until he has three or four hutches ready to be taken up the shaft. He waits at the " lye " until his turn or " ben " for lifting the hutches by carriage to surface, and after receiving his number of empty hutches, proceeds as before until his day's work is completed. Horses. — Haulage by horses from working faces, foot of cousie braes, and cut chain braes, is becoming common in the shale workings. When slope roads are driven in workings having an easy inclination it is found that a horse can take away the shale from three " faces," as against one by manual labour ; and as the workings, generally, have a high roof, good roads for horses are made at little expense. Self- Acting Inclines. — These may be classed under three heads : — 1. Cuddie Braes. 2. Cousie Braes. 3. Cut Chain Braes. A self-acting incline is merely an application of the law of gravita- tion, the weight of the load, together with the gradient of the incline furnishing the motive power, and from what has been stated regarding the inclination of the shale-measures it will be obvious that the work- ings are well suited for the adoption of this aid to the transit of shale. Underground Haulage. 129 The ciiddie brae (Fig. 60) is the simplest system of self-acting incline, and is used to a large extent. It runs one full hutch only at a time. The brae is laid with a double line of rails, one set having a narrow gauge on which runs the " cuddie " or loaded bogie balanced to suit the full and empty hutches. It is worked either by a rope or chain, — usually the latter — ^passing round a wheel, 18 to 20 inches diameter, attached to a forked piece of iron, one end of the fork being shaped so as to enter a vertical prop to which it is fixed by means of a screw and nut. The chain is passed round the wheel, and the speed of travel can be regulated by a handle attached to the fork, as shown in Fig. 61 ; but in most cases the " cuddie " is balanced so as to take up the empty hutch, and braking is unnecessary. The full hutch in descending draws up the " cuddie " to a short distance from the wheel, and the " cuddie," while descending, draws Fig. 60.— Cuddie Brae. Fig. 61. — Chain Pulley and Brake. up the empty hutch. To prevent the " cuddie " running back when the full hutch has reached the level road, the chain to which it is attached is pushed by the drawer's foot into a " gab " in a piece of iron bolted to a sleeper, and kept from moving by a pin and link. Cousie Braes. — By this system a number of loaded and empty hutches can be run at one time. Where the inclination is not steep, a wheel having a friction or braking strap is used, and round this the rope is passed two or three times to prevent slipping. In moderately steep workings a drum is preferred instead of a wheel, and it is also fitted with a strong brake. A number of full hutches arc put on at to]) of incline, and their weight, while descending, is sufficient to draw up an equal number of empties. This system gives general satisfaction. Cut Chain Braes. — The advantage of a cut chain brae is that the shale can be taken from a series of intermediate levels by one incline. 130 Methods of Working the Oil-Shales. The principle is the same as those akeady described, the full hutch drawing up the empty one. A wheel is fixed to a prop at the top of the incline, as shown in Fig. 02, and round this the rope passes. The rope is twice the length ^^'^ Nil M! ^.N^iA "^Z^Z/A N12 J "2^./^ z '^////A^^MV//////////. yyj I y/// ////////yy HooK Zrlllk ^^^7/7////////////////////, . Fig. 62.— Cut Chain Brae. of the brae, less the distance between the level and the first cut, and on one side is connected in sections by chain hnks. The method of working the cut chain will be best understood by reference to the foregoing sketch. Supposing a hutch is to be run from No. 1 Bench. The rope is cut by detaching the link, allowing the portion between Nos. 1 and 3 Benches, which is not required, to he between the rails. The rope being attached to the full luitch, and the signal given from below that the empty one is also attached, the blocks which have been holding the full hutch on the " plates " are removed, and it runs down to the bottom, B, the speed of travel being regulated as in Cousie braes by a brake, usually worked by a boy. The empty hutch has now been drawn up to No. lA, where it is taken off and another full hutch is run down, bringing up an empty to No 1. The rope can now be connected and hutches run either from Nos, 2 or 3 Benches, the process of " cutting " being carried out at each bench. Fig. 63 shows the links for connecting the lengths of rope, the connec- FiG. 63. -Hook and Link. Carnage Inclines. 131 tion being made by passing the hook through the link at the point marked A. This forms a substantial and reliable connection. Where these cut chain braes are in use, the inclination of the work- ings is 26°, and the average length of the braes is 40 fathoms. A large output can be run down one of these inclines. Carriage Inclines. — These are adopted where the inclination is great — 45° or thereby — the other systems being quite unsuitable at such acute angles. This system was largely practised in the mines of the Linlithgow Oil Co., Ltd., and is worked in those of the Pumpherston Oil Co., Ltd., in a seam having an inclination of 45°. The carriage (Fig. 64) is constructed to carry one hutch only, and is run on rails of the usual gauge, the balance bogie traveUing on a narrow gauge road. A drum about five feet broad and four feet in diameter is placed at the top of the incline, and is fitted with a brake Carriage for Self-acting Incline. and indicator having marks to represent the different stopping-places. Two separate ropes are used, one for the carriage, the other for the balance bogie. Under this arrangement the hutches are put on the carriage from one side only, and on the incHne under review there are seven stopping- places or benches. The principle of the carriage incline is the same as the self-acting cuddie brae, the carriage carrying the full hutch bringing np the balance bogie, and the latter, while descending, again Ijringing up the carriage bearing an empty hutch. Careful braking is necessary in order to bring the carriage to rest opposite the l^enches. The lengtli of the incline is 160 yards, and the outpvit is 70 tons per shift. This system has proved highly satisfactory, and is to be commended in like circumstances, the saving in wear and tear of hutches and the maintenance of output being factors of considerable value. 132 Methods of Working the Oil-Shales. Engine Haulage. — Two systems of engine haulage are now in common use, viz., direct or dook haulage, and endless rope haulage. Direct haulage is done by one main rope attached to a drum driven by an engine which may either be on the surface or underground. i The engine draws a train of full hutches up the dook to the bottom of pit or inclined shaft, and the empty hutches are run back by gravita- tion, dragging the rope behind them. The drum shaft is usually fitted with a clutch, so that the drum can be thrown out of gear with Inclined Shaft Winding. 133 the engine, and the empty hutches run down the inchne without reversing and running the engine. In this case the speed of the train is controlled by a brake on the drum. In some shale-mines electric motors are used instead of steam-engine for haulage, the generating plant being at the surface. The endless rope is another system of underground haulage which justifies itself when it can be applied on a long undulating road. The driving engine is on the surface, the rope being taken down the shaft, passed round pulley wheels, then put in line with the haulage road and carried to the terminus, where it passes round a horizontal wheel and is retm'ned to the drum. Two roads are necessary for this system — one for full, the other for empty hutches. A " jigger " fixed on the side of the hutches connects them to the rope. They are put on the rope at regular dis- tances apart, so that the load may be distributed as evenly as possible. Fig. 65 shows the endless rope arrangement. xi. Inclined Shaft Winding. In winding out of inclined shafts, the hutches are either drawn up in trains or " rakes," or upon a carriage with level platforms. When the grade of the incline exceeds 20°, a carriage is preferable, as it can be run at higher speed, and the number of derailments being small, its use tends to safety, economy, and more regular working. Hauling hy Electricity. — In recent years electric power has been adopted for hauling out of inclined shafts at the new openings of the Oakbank Oil Company at Duddingston, Linlithgowshire, The mines are driven in the Dunnet seam for 800 yards at an average gradient of 1 in 5, and the hutches are drawn by the endless rope system at a speed of 140 feet per minute. The hutches are put on the rope by attendants at special stations or benches, which are 40 fathoms apart, a distance of 40 feet being allowed between each hutch. As the rope passes over the top of the hutch the attachment is procm'ed by a short bridle chain, one end being hooked to the hutch and the other twisted two or three times round the rope, as shown in Fig. 66. Fig. 66. — Hauling by Endless Rope from Inclined Shaft. The output presently drawn by this system is 500 tons per shift, but these figures can be largely exceeded if necessary. The rope is 1| inches diameter, and is kept tight by a travelling bogie or back 9 134 Methods of Working the Oil-Shales. balance placed at the foot of the mine. Pulleys of mushroom shape are placed at the benches to carry up the rope so as to allow the hutches to be attached or detached. Hutches having to be taken across the incline are carried on an ingenious overhead scaffold, advantage being taken of the gradient of the mine to have a level roadway. The power for this arrangement is got from a Westinghouse induc- tion motor, started and stopped by a controller of the type used on tramways, and having an output of 150 B.H.P. The di'um is 10 feet diameter, the ratio of gearing to motor being 1 to 120. xii. Conveyance of Shale on Surface. The hutches containing the shale, when delivered at the pithead, are examined by the shale inspector or " crowpicker," who rejects unsuit- able material. They are then weighed, and the weight credited to the " placeman " or contractor who has sent them up, a piece of leather, tin, or other material of particular shape attached to one of the rings of the hutch being the pitheadman's invoice, or label, indicating name of sender. The designs and shapes of these labels or " pins " are mystifying to those not experienced in mining affairs, but it is of rare occurrence to hear of a pitheadman having made a mistake in crediting a hutch. After the weighing process the hutches are emptied direct into the Fig. 67.— Shale Breaker. Shale-breaking Machine. 135 shale-breaking machine, or sent by endless haulage arrangement or railway trucks to that machine. This altogether depends on the distance of the pithead from the breaker. The process of emptying the hutches is facihtated by a tippler placed over the shoot leading into the shale breaker, and the waggons are usually discharged by the aid of a hydraulic ram. The shale-breaking machine consists of two heavy cast-iron rolls placed in relation to each other, as shown in Fig. 67, and driven by steam-engine or electric motor through belt or gearing. The rolls have heavy cast-iron teeth which crush or break the shale in passing through and deliver it by a shoot into hutches on railway at bottom of breaker, from whence it is conveyed to the retorts. PART III. THE CHEMISTRY OF THE OIL-SHALES. i. Introductory and Historical. The raw material is bituminous shale, which, after being broken up by machines of special construction, and subjected to destructive distillation in retorts, gives crude oil, ammonia water, and gas used as fuel. The crude oil is refined by repeated distillations and "treat- ments with chemicals, and the marketable products are — (1) Shale spirit or naphtha, with specific gravity from '660 to •750 at 60° F. (15"5° C). Oils too volatile for safety in domestic illum- ination, and used chiefly as solvents, and for motor spirit. (2) Bittning or lamp oils. Sp. gr. '770 to -830, the average being about "800. Used for lamps and internal combustion engines. (3) Gas or intermediate oils. Sp. gr. "840 to "865, with properties intermediate between those of the biu^ning and lubricating oils, and used for gas-making, gas-enriching, fuel for the Navy, internal combus- tion engines, and for cleaning pm'poses. (4) Lubricating oils. Sp. gr. "865 to '895, of high boiling-point and viscosity, used for lubricating machinery. (5) Solid parafiin. Melting-points from 100° to 130° F. (38° to 54° C). Used for candle-maldng and other purposes. (6) Still coke, still grease, &c. (7) Still gases used for illuminating the neighbouring villages. From the ammonia water is obtained — (8) Sulphate of ammonia. History of the Oil-Shale Industry. The manufacture is allied to the gTeat petroleum industry and more closely to the oil-shale manufacture in France and the brown coal distillation of Germany. The distillation of coal for liquid products was attempted in Scot- land more than a hundred years ago, but then proved unsuccessful. Shale distillation was begun in France some years earlier than in Scot- land, and still exists ; but in this country .the French experiment was unknown and the industry originated here independently. In Decem- ber 1847, Mr. James Young was informed of the existence of petroleum at Alfreton, in Derbyshire, by the late Lord Playfair, who held that he thereby originated not only the shale-oil manufacture of Scotland, but also the great petroleum trade of the world. Young worked the petroleum from the Alfreton coal pit until it was exhausted. His 136 History of the Industry. 137 theory was that it had been produced in the earth by the distillation of coal at a low temperature, and he set himself to produce a similar oil artificially. He experimented with many varieties of English and Scottish coal, mitil eventually he found the Torbanehill or Bog- head gas-coal in West Lothian, which proved suitable for his pm*pose. He took out his patent for the low-temperature distillation of coal in 1850 ; and by the end of that year the Bathgate works were started by Messrs. Young, Meldrum and Binny. '■ At the Loudon Exhibition in 1851, Mr. Young was awarded a medal for the distillation of paraffin oil from coal, and at the same time A. Wiesmann & Co., of Augustenhiitte, near Bonn, Prussia, ob- tained one^for paraffin oil from shale ; A. Moreau, of Paris, one for similai'l products, from bitumen; and V. Dehgnon, France, was honourably mentioned for rectified products from shale. Dehgnon remarked that the French industry was more successful than that of Scotland owing to less sulphur being present. js*:], The Torbanehill Jmineral yielded the raw material for about a dozen years, much of it being used in Scotland and some being ex- ported to'J America and the Continent for distillation. In 1862 the supply from this source was being exhausted, and the material became too valuable and expensive for this industry ; hence shale was resorted to, but with widely different results. While the Torbanehill {mineral yielded about 120 gallons of crude oil per ton, the shales first used f lu-nished 40 to 45 gallons, and soon the yield was 30 to 35 gallons. The expiry of Young's patent in 1864 led to a rapid expansion of the Scottish oil industry, but ere long it sustained a severe check. The discovery in 1859 of oil-wells in Pennsylvania by E. L. Drake, was soon followed by the importation of petroleum lamp oil into Britain, the quantity increasing year by year. Owing partly to this competition and partly to the increase in the number ^of oil works, prices gradually fell. Dming the course of Young's patent, the price of biurning oil, the principal product, was 2s. Qd. per gallon, and even 3s. Qd. for a short time ; soon after its expiry it was lowered to Is. 6cZ., and for some years it ranged from Is. 55. to Is. In 1871, fifty-one works existed in Scotland, producing 25,000,000 gallons of crude oil per year, and within two years the number was reduced to thirty. Competition with American and Russian Supplies. At first the Americans exported to Britain only bm-ning oil, but they soon began to introduce supplies of lubricating oil, and, sub- sequently, of solid paraffin. Then the smaller works (whose retorts had been mostly made for the production of burning oil) tended to decrease in number, and the larger ones to increase in size, thus con- centrating and cheapening production. Retorts were improved to suit the circumstances and to produce a purer oil with a larger pro- portion of heavy products. Mechanical labom'-saving arrangements were devised, refining was improved and cheapened, and economies of every kind were introduced. The chemicals used in refining were recovered ; and the tars separated by them, the removal of which had involved expense, now became a source of profit as fuel. The supply of Peruvian guano began to fail, hence the price of sulphate of ammonia rose to £22 (1880) and even to £24 per ton ; but as the 138 Chemistry of the Oil-Shales. importation of nitrate of soda increased greatly, it fell below £8 per ton about 1890, when burning oil sold at less than 6d. per gallon. These conditions led to further concentration. Retorts specially designed for the manufacture of sulphate of ammonia were universally adopted, and improvements were introduced to secure greater economy of working. With the older type of retorts a shale had to yield about 30 gallons of crude oil per ton in order to be profitable ; but with the new retorts, and the increased yield of ammonia and fuel gas, a shale fiu-nishing 20 gallons is remunerative. Not more than 16 lbs. of sul- phate of ammonia per ton were formerly obtained as a maximum, now 35 lbs. to 70 lbs. are got, according to the quaUty of the shale. By these methods the quantity of shale that can be worked with profit has been increased, and the life of the Scottish industry has been lengthened. Since 1873, the Russian petroleum industry has developed rapidly, and in recent years competition from this som-ce has become very severe. Russian crude oil, however, produces no solid paraffin ; and America shows signs of not being able to respond as easily as formerly to the increasing demands of the world for petroleum, any increase in American output being fuel oil. In 1905, however, it succeeded by great effort in making up for the Russian deficiency caused by troubles at Baku. In 1909 and 1910 there was a definite decrease in the export of burning oil from America to Britain. Sul- phate of ammonia is being produced in greater quantities from iron- works, coke-ovens, Mond-gas producers, &c. ; but the demand also increases. New competitors are always arising ; recently, for instance, Galicia with solid paraffin, Roumania with burning oil, and the Dutch East Indies with motor spirit. But notwithstanding this prolonged and fierce struggle for existence the Scottish industry still survives. The Scottish companies vie with each other in their efforts to improve and cheapen the processes, and show signs of mutual helpfulness and co-operation. In the early days of the industry operations were carried on in a simple but very expensive fashion. Sometimes the shale was carted miles to the retorts, and the crude oil carted miles to the refinery, and breaking shale, pumping oil, &c., were done by manual labour. But through all these years evolution has been at work in developing a high state of organisation, resulting in economy and efficiency. The most of the existing works have adopted elec- tricity for lighting and for the conveyance of power for all purposes. In 1894 there were thirteen oil companies in Scotland, now there are only seven (three of which produce crude oil only), but the output has not been reduced. ii. Statistics. It is not possible to obtain full and reliable data in regard to the production of the oil-shale industry in Scotland ; the following are approximate estimates showing its extent : — In 1910 the Shale distilled was . . . 3,130,000 tons. The Crude Oil produced 273,000 tons or . . 70,000,000 gallons. The marketable products were — Motor Spirit ...... 600,000 gallons. Naphtha ...... 4,400,000 „ Burning Oil . . . . . . 20,000,000 „ Gas or Fuel Oils ..... 12,000,000 „ Statistics of Production. 139 Lubricating Oils ..... 10,000,000 gallons. Paraffin Wax ...... 25,000 tons. Sulphate of Aninioniu .... 54,000 „ The value of total products .... £2,000,000. In 1909, 4496 miners were employed. Mines and oil works together employed about 10,000 men. The following table gives the quantities of shale and products for years ending important periods in the history of the industry : — 1871. 1879. 1887. 1893. (51 Works.) (18 Works.) (13 Works.) (13 Works.) Sliale . 800,000 tons. 850,000 tons. 1,869,300 tons. 1,947,842 tons. Crude Oil . 25,000,000 galls. 29,000,000 galls. 52,876,700 galls. 48,696,050 galls. Naplitha,buruiug, aud Gas Oil 11,250,000 „ 11,400,000 „ 21,680,000 „ 20,452,341 ,, Lubricating Oil . 2,500,000 „ 5,000,000 „ 9,000,000 „ 8,765,289 „ Paraffiu, Solid 5,800 tons. 9,200 tons. 22,846 tons. 19,130 tons. Sulphate of Am- monia • 2,350 „ 4,750 ,, 18,483 „ 28,000 „ Prices of Products. 1873. 1883. 1893. 1903. 1910. 1912. (May). Burning Oil — per gallon Heavy Oil — per ton . Refined Paraffiu — per lb. Crude Paraffin Scale — per lb. Ammonia Sulphate— per ton Is. 5d. £20 lOd. 5d. £20 5fd. £9 10s. 4d. £17 5id. £5 5d. 2id. £10 5fd. £6 3d. £12'iOs. 5d. £5 10s. 2d. £12'i5s. 8d. £6 2id. £13 15s. The follo^ving tabular statement shows the growth of the manu- facture dming the last thirty-eight years : — • Output and Value of Oil-Shale in the United Kingdom from the Year 1873 to 1910. Home Ojfi. ce Repijrt : Mines and (^ UARRIES. Part III. p. 276 (1910). Year. Quantity. Value. Year. Quantity. Value. Tons. £ Tons. £ 1873 524,095 262,047 1892 . 2,089,937 522,484 1874 362,747 181,373 ' 1893 1,956,520 489,130 1875 437,774 218,887 1894 1,986,385 496,596 1876 603,538 301,769 1895 2,246,865 561,716 1877 801,701 400,850 1896 2,419,525 604,881 1878 783,704 394,352 1897 2,223,745 555,936 1879 783,748 391,824 1898 2,137,993 534,498 1880 837,805 418,902 1899 2,210,824 553,003 1881 958,255 479,127 1900 2,282,221 627,844 1882 1,030,915 310,685 1901 2,354,356 589,162 1883 1,167,943 299,676 1902 2,107,534 500,804 1884 1,518,871 386,780 1903 2,009,602 477,312 1885 1,770,413 447,302 1904 2,333,062 544,346 1886 1,728,503 435,963 1905 2,496,785 593,334 1887 1,411,378 355,085 1906 2,546,522 657,928 1888 2,076,469 519,074 1907 2,690,028 806,323 1889 2,014,860 503,715 1908 2,892,039 795,257 1890 2,212,250 608,369 1909 2,967,057 815,937 1891 2,361,119 707,177 1910 3,130,280 860,827 140 Chemistry of the Oil-Shales. County Output and Value of Oil-Shale froia Mines for 1910. Home Office Report : Mines and Quarries for 1910. Part III. p. 276. County. Average Value Quantity. per Ton at the Mines. Value at the Mines and Quarries. E(linbur<;h .... Lanark and Sutherland Liiilitligow .... Tutal in 1910 Tons. 728,058 84,060 2,318,162 s. d. 5 6 5 6 5 6 £ 200,216 23,116 637,495 3,130,280 860,827 Sulphate of Ammonia- -Annual Production in the United Kingdom. From H.M. Alkali Inspector's Reports. 1886. 1887. 1 1888. 1889. i 1890. 1891. 1892. 1893. 1894. li95. 1896. Gas Works Iron Works Shale Works . Coke X- Carbon- ising Works . Total Tons. 82,480 3,950 18,080 2,100 Tons. 85,022 5,098 21,098 2,678 Tons. 92,896 5,280 22,072 2,537 Tons. 100,711 6,145 23,953 2,795 Tons. 102,138 5,064 24,730 2,325 Tons. 107,950 6,290 26,000 2,766 Tons. 110,748 11,000 23,105 4,973 Tons. 112,179 8,833 28,485 3,265 Tons. 113,634 10,075 32,891 3,448 Tons. 119,045 14,588 38,335 7,0S3 Tons. 127,498 16,511 37,822 9,078 106,610 113,896 122,785 133,604 134,257 143,006 149,826 152,762 160,048 179,651 190,909 1897. 1898. 1899. 1900. 1901. 1902. 1903. Gas Works . Iron Works . Shale Works Coke Works Producer Gas & ( Jarbonisinjj Works . Total . Tons. 132,724 17,779 37,153 10,624 Tons. 129,590 17,935 37,264 11,568 Tons. 133,768 17,963 38,780 7,849 7,300 Tons. 142,419 16,959 37,267 10,393 6,6i8 Tons. 142,703 16,353 40,011 12,2.55 5,891 Tons. Tons. 150,055 149,489 18,801 1 19,119 36,931 ! 37,.353 15,352 i 17,438 8,177 ; 10,265 198,280 196,357 205,720 213,726 217,213 229,316 233,664 1904. 1905. 1906. 1907. 1908. 1909. 1910. Gas Works . Iron Works . Shale Works Coke Works Producer Gas & ( Jarbonisinj; Works . Tons. 150,208 19,568 42,486 20,848 12,880 Tons. 155,957 20,367 46,344 30,732 15,705 Tons. 157,160 21,284 48,534 43,677 18,736 Tons. 165,474 21,024 51,338 53,572 21,873 Tons. 165,218 18,131 53,628 64,227 24,024 Tons. 164,276 20,228 57,048 82,886 24,705 Tons. 167,820 20,139 59,113 92,605 27,850 T otal , 245,990 269,114 289,391 313,281 325,228 349,143 367,587 The production of sulphate of ammonia from shale works in these years has all been from Scotland, and the supply is now derived wholly from our own district. The small Scottish paraffin oil industry may be looked on as part of the great petroleum trade of the world. " The Production of Petroleum in 1909," by Dr. David T. Day, United States Geological Survey, 1911, makes the total world pro- Trade Statistics. 141 duction of petroleum in 1909, 39,804,607 metric tons, and the output from the different countries is — United States, 61 "24 per cent. ; Eussia, 22*19 per cent. ; Galicia, 5*02 per cent. ; Dutch East Indies, 3*71 per cent. ; Roumania, 3*13 per cent. ; India, 2*24 per cent. ; and other places less than 1 per cent. each. The imports of Petroleum into the United Kingdom in 1909 were (Mines and Quarries, III., 1910, p. 264) :— Gallons. Value. From Russia .... 27,824,129 £535,792 „ United States . . . 268,532,909 4,190,779 „ Other Countries . . . 61,745,829 1,394,631 Total .... 358,102,867 £6,121,202 The Scottish production of crude oil is 18 per cent, on the import of total petroleum. The following figures are fi'om the " Annual Statement of the Trade of the United Kingdom for 1909," Vol. I. :— Imports of Petroleum (1909). Gallons. Value. Crude Oil ... . 1,185,510 £16,080 Lamp Oils .... 146,817,880 £2,294,606 Motor Spirit .... 34,226,223 £844,370 Spirit ..... 17,697,058 £368,322 Lubricating Oils .... 53,902,864 £1,631,365 Gas Oil ..... 71,586,006 £690,186 Fuel Oil . . . . . 32,687,326 £276,273 The quantity of lamp oil made in Scotland as compared with the quantity imported is 14 per cent. The quantity of fuel oil made is 37 per cent, on what is imported. The paraffin wax imported in 1909 was 1,049,004 cwt., value £1,126,035. The paraffin wax exported was 348,266 cwt., value £407,024. The parafiin wax imported in 1910 was 53,159 tons, or twice the Scotch production. Not many years ago Scotland, with its production of about 20,000 tons a year, was the principal source of the world's solid paraffin ; but now the Standard Oil Co. of America produces 100,000 tons, Galicia, 60,000 tons, Germany (from brown coal), 7,500 tons, and there are considerable quantities from Burmah and other countries. The paraffin candles made in the United Kingdom in 1903 were 60,000 tons. Of these, 12,100 tons were of Scotch parafiin wax, or 20 per cent. iii. Minerals Now or Formerly Used. Outside the shale-fields in the Calciferous Sandstone Series, shales and parrot coals of the Coal-measm-es have been used in Scotland, for instance in Fife, Ayrshire, and Lanarkshire. In the Airdrie neigh- bourhood seams were worked for oil in connection with the Splint and Virtuewell coals, the Mussel-band ironstone, and the Kiltongue coal. At Rosewell, Midlothian, there was a small oil work that formerly distilled an eight-inch shale, found in the middle of the Parrot Rough Coal — the second lowest seam now worked in theCoal-measm'es in that district. The following is a list of the principal shales worked in the Lothians, beginning with the highest in the geological sequence : — 142 Chemistry of the Oil-Shales. 1. The highest seam of importance formerly -WTOught in the Lothians was the Torbanehill or Boghead Mineral, its position being near the base of the Coal-measures overlying the Millstone Grit. Originally it was mined to some extent as a gas-coal, and it was used for this same purpose after it became too expensive for making paraffin oil. 2. The next seam — one of the earliest shales worked — which measured 11 inches in thickness, and yielded 29 gallons of oil per ton, is in the Carboniferous Limestone formation immediately above the Levenseat Limestone, or separated from it by a thin parting. It may, perhaps, be held to represent the Parrot Coal mined at West- field, Fife, for eighteen years, its position being 6 feet above the Levenseat Limestone. Associated with the Lochgelly ironstone is a shale which fm-nished 32 gallons per ton. About 40 fathoms above the Hm-let Coal is a band of shale which supplied the Renfrewshire Oil Works, and yielded 45 gallons per ton. 3. Raeburn Shale, or Damhead Shale, from 3 to 5 feet thick, or sometimes 5 to 6 feet, including the blaes or fireclay with it, has been wrought at West Calder, Tarbrax, and Charlesfield. At South Cobbin- shaw, 16 fathoms above the Raebiu'n Shale, there is found a shale called the Uj^per Raeburn or Fraser Shale, yielding about 30 gallons a ton and 29 lb. sulphate of ammonia. 4. Mungle or Steuart Shale, 2 feet at West Calder. The Tivo-foot Coal seam, either cannel or smithy coal, was used at Drumcross and at Westwood. It was worked by Robert Bell at Brox- bm-n, together with 17 inches of shale — yielding 27 gallons of oil per ton — and 4 inches of ironstone above this shale. At another place in the Broxbm-n field there were 17 inches of shale, giving 41 gallons per ton. 5. Grey Shale of Addietvell, which was mined at that locality and at Kirkliston, about 1 foot 8 inches in thickness. The crude oil yielded much solid paraffin. 6. Fells SJiale, from 3 to 5 feet thick at West Calder and in places about 7 feet, mined at Addiewell, Tarbrax, Breich, Seafield, Hermand, and Pentland. It is the principal shale in West Calder district. 7. Wee Shale of Oakbank, 2 feet thick ; not worked. 8. Big Shale of Oakbank, i^ feet thick, used at Oakbank. 9. Wild Shale of Oakbank or Lower Big Shale, Grey Slmle of Broxbm-n, worked at Oakbank and Broxburn, 6 feet at Oakbank and at Broxbm-n. 10. Curly Shale of Broxburn and Oakbank, mined at Broxburn, Oakbank, and Dalmeny, 6 feet in thickness. 11. Broxburn Shale, AI'Lean Shale of Oakbank, Under Shale of West Calder district, 4 feet thick at Oakbank, 4 to 6 feet at West Calder, 5 to 6 feet at Broxburn ; worked at Addiewell, Seafield, Hermand, Oakbank, Broxburn, Niddry, Linlithgow, Philpstoun, Pentland, and Dalmeny. It is the principal shale of the Broxbm-n district. 12. Lower Wild Shale of Oakbank, 4| feet thick, worked at Oakbank, represented at Broxburn by a seam 9 to 18 inches in thickness and from 14 to 16 feet under the Broxburn Shale. 13. Champfleurie Shale [Wee Dunnet of Linlithgow district), which may correspond to the Loiver Wild Shale of Oakbank. In veins in the Binny Sandstone below this seam was found the Binny Chemical Composition. 143 ozokerite, which supplied the household light of Uphall parish a hundred years ago. 14. Dminet Shale, from 6 to 12 feet thick, worked at Hermand by Mr. Dunnet, at West Calder, Oakbank, Newliston, Pentland, Biu-ntisland, and Pumpherston. It is the principal shale of the Pentland, Burntisland, and Duddingston fields. About 10 fathoms below the Dunnet Shale a layer was found to the north of Broxburn, charged with petroleum and brine. (See p. 166.) 15. Oakhank New Shale, sometimes termed the Lower Dunnet seam, worked at Oakbank, and at south-east part of Pumpherston field. About 66 feet below this horizon there is a seam 2 feet thick, and 22 feet fm'ther down another layer over 6 feet, both of them not worked at present. 16. Barracks Shale, known also as the Pattison Shale at Deans, worked at Deans and Linlithgow. At Raw Camps the Ca7nps Shale is 8 feet thick and yields 22 gallons of oil per ton. 17. Pum]ihersto7i No. 1 or Jubilee "Shale, 8 feet in thickness, now mined at Roman Camp and formerly at Holmes and. Pumpherston. 18. Pumpherston No. 3 or Mayhrick Shale, 5 feet 3 inches ; for- merly worked at Holmes and Pumpherston, now at Roman Camp. 19. Pumpherston No. J or Pumpherston Curly Shale, 6|- feet, now mined at Roman Camp and formerly at Holmes and Pumpherston. 20. Pumpherston No. ^ Plain Shale, 6| to 7| feet, worked at Roman Camp and formerly at Holmes and Pumpherston. 21. Pumpherston No. 5 or Under Shale, 4 to 5 feet, worked at Roman Camp and formerly at Holmes and Pumpherston. iv. Chemical Composition of the Valuable Shales. This branch of inquiry is discussed under the following heads : (1) The crude oil and ammonia of shales as determined in the labora- tory ; (2) The analyse ^ of crude oil from the dift'erent seams ; (3) The general chemistry of the shales. For convenience of description we may apply the name " kerogen " * to the carbonaceous matter in shale that gives rise to crude oil in distillation. 1. THE CRUDE OIL AND AMMONIA OF SHALES AS DETERMINED IN THE LABORATORY. Regarding the crude oil and ammonia of the dift'erent shales, it is difficult to obtain detailed information for the whole field, but we furnish details of selected localities which should give the reader a general impression of the whole. A noteworthy feature is the remarkable variation in the yield of crude oil and sulphate of ammonia of the different seams and of the same shale when traced across the area. For example, the Torbanehill Mineral itself was richer in the east part of the field than in the west, and it distinctly deteriorated with depth also. The Raebiu'n seam was well developed in a small area in the south-west of the shale district ; the Fells seam was richer in the west where other seams * We are indebted to Professor Cram Brown, F.R.S., for suggesting the term "kerogen "to express the carbonaceous matter in shale that gives rise to crude oil in distillation. 144 Chemistry of the Oil-Shales. were of inferior quality. The Broxburn seam is at its best about Broxburn, and deteriorates all round and particularly towards the north-west ; and the best quality of the Dunnet Shale was found in the east. It would appear that each important seam has its locality of greatest excellence. The highest shale in the series, the Torbanehill Mineral, was the richest in crude oil, supplying 130 gallons per ton at its best, but only a few pounds of sulphate of ammonia. As we descend in the sequence there is a lower yield of oil, but an increase in the yield of sulphate of ammonia. For example, in the lowest shales — the Pumpherston or Roman Camp group — the oil obtained averages about 20 gallons per ton, while the sulphate of ammonia amoimts to about 60 lb., which is double the quantity of ammonia of the higher shales. In a basin where the oil of the Broxburn seam diminishes with the depth there is a slight increase of ammonia. Yield of Oil in Relation to Depth of Shale from Surface. There seems to be a general law, not without exceptions, that shales deteriorate with depth. This featm'e is very marked in the Linlithgow district in the case of the Broxbm'n seam ; very distinct but not so acute at Broxburn, much less apparent at Oakbank, while at Pentland increase of depth does not seem to diminish the yield of oil at all. This deterioration with depth is gTeatest towards the north, and it decreases towards the south. The kerogen may be amenable to pressure under heat and slightly mobile, but we must remember that the present thicloiess of strata at any particular point is no indication of the thickness in past geological time ; and fm'ther, we should bear in mind that a great load of overlying materials probably implied increased temperatm*e. If pressure be looked on as the cause of the decrease in oil with depth, then some accidental circumstance has in certain cases increased the pressure near the outcrop, and in others diminished it at greater depths. During the folding and faulting that took place long after the deposition of the sediments this might sometimes have happened. At a sudden bend in the strata there is occasionally a great reduction in the yield of oil. Again, near a slip or fault in the strata where one might expect that the pressure would have been increased, plain shale of the ordinary seam was represented by curly, and the crude oil was increased from 30 to 40 gallons. There might, however, have been a local diminution of pressure at the point in question. On an incline in the Broxburn seam, near Broxburn, samples were taken at varying intervals in the gi'adual descent which yielded the following results by the laboratory tube-retort. The amounts of crude oil obtained by this method agree pretty well with those in the works, but the ammonia of the laboratory tube requires to be doubled to give an approximate works-yield of sulphate of ammonia. In the following tables where the results are not marked " laboratory tube " they are either from the works-retort or the large scale experimental retorts that give an ammonia-yield equal to that of the works. [Table Yield of Crude Oil and Sulphate of Ammonia. Broxburn Shale, Laboratory Tube Results. 145 Depth, Vertical. Gallons ) Crude Oil. J Near Outcrop. 31-8 i / 29-6 438 ft. 30-7 821 ft. 24-1 912 ft. 25-8 24-8 965 ft. 22-5 1077 ft. 17-3 / Greatest 1, Depth. 13-5 Lbs. Sulphate 1 of Ammonia. J 9-3 10-5 10-4 15-4 11-6 13-4 9-0 16-6 17-1 In another basin the figures for crude oil were in descending order, 29-5, 31-3, 28-7, 27-3, 24-2, 23-3, 22-0, 26-1. At the greatest depth in this case a rise took place where a fall was expected. The following results were obtained from the Broxburn curly and Broxburn grey seams (Laboratory tube tests) : — Broxburn Curly Seam. Vertical Depth. Crude Oil. A mmonia Sulphate. 13 Fathoms 71 Fatlioms 109 Fathoms Top, 2 ft. 5 in. . Bottom, 2 ft. 11 in. Average Top, 2 ft. 4 in. . Bottom, 2 ft. 8 in. Average .... Top, 1 ft. 11 in. . Bottom, 3 ft. Average .... Galls. 25-77 27-42 Lbs. 19-7 19-7 26-67 19-7 . 31-12 22-56 19-81 18-14 26-70 18-93 22-40 20-85 21-98 19-77 21-45 21-29 Broxburn Grey Seam. Vertical Depth. Crude Oil. Ammonia Sulphate. 13 Fathoms 71 Fathoms 109 Fathoms Top, 2 ft. 11 in. . Bottom, 3 ft. 2 in. Average .... Top, 2 ft. 9 in. Bottom, 2 ft. 10 in. Average .... Top, 2 ft. 8 in. Bottom, 3 ft. Average .... Galls. 23-31 24-90 Lbs. 19-23 19-79 23-65 19-51 20-37 18-65 19-45 19-23 19-49 19-33 19-77 17-6 23-45 21-12 22-21 18-62 IIG Chemistry of the Oil-Shales. Yield of Crude Oil and Sulphate of Arumonia. Owing to the variable character of the shales it is difficult to get a true average sample of any seam for analysis. At first sight a bore core seems a perfect method of obtaining it, and yet materials got from bores cut within a foot of each other sometimes differ by two or three gallons or even more, in the yield of oil. For determining the specific gi-avity also it is not easy to get a piece representing the average of the whole thickness of any seam. The shales from the Upper Coal-measures give a crude oil of high specific gravity. Airdrie Shale from upper part of Kiltongue Coal seam, Springwell Colliery, gave 33 gallons of crude oil. Sp. gr. -957. Setting point 65 degrees. Sulphate of ammonia 6 lb. (lab. tube). Monkland Shale 32 gallons, sp. gr. -960, and sulphate of ammonia 6^3 lbs. Shale from Westfield, Rutherglen, 24| gallons. Sp. gr. -961. Sulphate of ammonia 10 lbs. These laboratory tube experiments give an oil with specific gravity higher than the present retort, and corresponding roughly to that of the old vertical retort. 1. The Torbanehill Mineral varied from 90 gallons or less to 130 gallons. 2. The Levenseat Shale (Carboniferous Limestone Series). — A sample tested at Broxburn gave 34^3 gallons, sp. gr. -904, and sulphate of ammonia 4-3 lbs. (lab. tube), 3. Raeburn Shale. — In the Broxburn field, in a basin to the east of Uphall, this seam has a thickness of nearly 4 feet, and gives 54| gallons per ton. Sp. gr. -887, Sulphate of ammonia 7 lbs. (lab. tube). 4. The Mungle Shale, which was worked at Gunsgreen by Messrs. Raeburn, yielded 35 gallons of oil per ton, and at Cobbinshaw 34 gallons. At Middleton, Uphall, the average of 3 feet 1 inch amounted to 36 gallons of crude oil and 30 lbs. of sulphate of ammonia. 5. Addieivell Grey Shale. — A block of this material from AVestwood that had been weathered for thirty-five years gave 28^3 gallons. Sp. gr. -879. Setting points 93 degrees — which indicates much solid paraffin — and sulphate of ammonia 6| lbs. (lab. tube). At Newbigging, near Broxburn, about 4 feet of this seam contains 28 gallons, and the overlying 11 inches, 11 gallons. Sulphate of ammonia 9 lbs. (lab. tube). 6. Fells Shale.— It yields 26 to 40 gallons of crude oil and 20 to 35 lbs. of sulphate of ammonia per ton with the retort of Young and Beilby. At Sandhole Pit, near Broxburn Oil Works Refinery, it was tried in sections. Crude Oil. Sulphate of Ammonia. Bottom, 4 inches Next, 13 „ ... )) 4 „ ... Top, 6 „ ... Gallons. 30-1 32-7 509 35^4 Sp. Gr. •891 •895 •895 •893 Lbs. (Lab. Tube). 13-6 113 9^4 7^2 Average of 27 inches, 35-6 gallons. Yield of Crude Oil and Sulphate of Ammonia. 147 At Holygate Bridge. Broxburn, this shale yielded 42| gallons at a depth of 30 fathoms, and at Loaning Hill it varies from 25 gallons to over 40 gallons. From Hermand the top part of the seam gave, in retorts at Brox- burn, 29 gallons of oil and 31 lbs. sulphate of ammonia, and the bottom part, 23| gallons and 31 lbs. At Starlaw, on Lord Rosebery's estate, it yielded 35 gallons of oil per ton. At Pentland, in Midlothian, where this seam is about 2| feet thick, 32 to 34 gallons of oil per ton were generally obtained, and occasionally over 40, and from 19 to 20 lbs. of sulphate of ammonia. The following results show the variations in the Pentland field at different localities. The sp. gr. of the shale was the mean of determinations of several pieces from the same place. Sp. Gr. of Shale .... 1-740 1-749 1-656 1-744 1-760 Crude Oil, gallons per ton 40-86 3900 47-72 37-40 36-84 Sp. Gr •894 -898 •889 -894 •897 „ Setting Pt,. . 86-5° F. 90-0° F. 87° F. 91° F. 86° F. Ammonia Sulphate, lbs. per ton 24-91 25-65 24-76 29-55 29-5 7. Oakbank Wee Shale, 2 feet thick, gives 35-59 gallons of crude oil per ton at Oakbank. 8. Oakhank Big Shale, 4 feet, 22-32 gallons per ton. Nitrogen in it 0-720 per cent. 9. Broxburn Grey Shale. — At Broxburn it varies from 24 to 26 gallons. Li one place it is as low as 20 gallons, at another as high as 33. Sulphate of ammonia 34 to 36 lbs., and even 41 lbs. The Lower Big Shale at Oakbank, 6 feet, 29'34 gallons per ton. 10. Broxburn Curly Seam, which is about 5 feet above the Brox- burn seam at Broxburn. The following sections are given as ex- amples : — Oil. Sulphate of Ammonia. One Section . Another Section Another Section Ft. In. Top . .28 Bottom . .22 Galls, per Ton. 18-57 28-56 Lbs. per Ton (Lab. Tube). 19-17 17-04 Average of . 4 10 23-05 18-21 Top . .28 Bottom . . 1 10 30-4 20-12 17-04 14-91 Average of .46 26-21 16-17 Top . .27 Bottom . .25 32-67 31-26 19-41 19-73 Average of . 5 32 19-56 148 Chemistry of the Oil-Shales. Section at Crossgkeen (Lab. Tube). Oil. Sulphate of Ammonia. Bottom, 6 inches Next, 6 „ „ 12 „ „ 10 „ „ 20 „ » 10 „ Average of b\ feet . Galls, per Ton. 28-5 25^2 20^4 320 21-1 30-7 Sp. Gr. •879 •874 •862 •870 •875 •874 S. Pt. 84° F. 68°,, 78° „ 85° „ 70° „ 66° „ Lbs. per Ton. ir8 14-1 24-0 193 16-7 Plain. 16-7 Curly. 25^1 •872 74° F. 17^7 At Oakbank — Top, 2 feet 9 inches, 28^0 gallons Crude Oil. Bottom, 1 foot 11 „ 2M2 „ „ The total nitrogen average of both top and bottom is 0^575 per cent. 11. The Broxburn seam varies from 40 gallons per ton, which has occasionally been obtained as the average of the total thickness of over 5 feet, to 20 gallons, and in deep parts at Linlithgow about 10 gallons. Selected parts of the shale have yielded 65 • 6 gallons per ton. The following is taken at random from many sections that have been tested in detail (laboratory tube) : — Oil. Sulphate of Ammonia, Ft. In. Bottom . . .06 Next . . .21 ,,...09 , . . .12 Top . . . 10 Gallons. 27-4 50^1 28^4 32^4 27-7 Sp. Gr. •874 •893 •886 •891 •897 Lbs. 70 12-6 130 10-4 12-5 Average of . .54 37-3 n-Q At Pentland this seam was variable, and latterly the oil obtainable fell off to such an extent that it was no longer mined. Yield 20 to 24 gallons, and in places only 18 gallons ; sulphate of ammonia 20 lbs. The deterioration increased along the strike to the north-east. The following results from the Pentland field show the variation throughout the seam at the same place : — Sp. Gr. Oil. Sulphate of of Shale. Ammonia. In. Galls, per Ton. Sp. Gr. S. Pt. Per Ton. 1st Parting 7 2^151 18-43 •883 87° F. 17^14 2nd „ 2 1^940 29-27 •883 90° „ 16-99 3rd „ 5 1-980 31-47 •896 87° ;; 21-94 4th „ 9 1-768 39-20 •896 83° „ 23-46 5th „ 12 2-193 16-10 •891 82^5° F. 21-25 6th „ 4 2^260 15-41 •892 85° F. 21-57 Total depth 39 Yield of Crude Oil and Sulphate of Ammonia. 149 The M'Lean Shah at Oakjank, very little of which has been worked for some 5''ears, was 5 feet thick, and gave 38-40 gallons of crude oil per ton, and contained nitrogen 0-646 per cent. 12. Lower Wild Shale at Oakbank, 5 feet 6 inches thick, gives 19-25 gallons per ton. 14. The Dunnet Seam, near Queensferrij, gave 33 gallons of oil and 33 J lbs. of sulphate of ammonia. At Duddingston, where this seam is worked by the Oakbank Company, it gives — Top, 2 feet 4 inches .... I 27-99 Gallons Crude Oil i)er Ton. 3 „ „ 20-23 5 „ „ 3431 1 „ 10 , fi-T8 2 „ 8 „ 25-38 „ „ 1 „ 5 „ 11"20 „ „ „ At Newliston one section gave — Oil. Sulphate of Ammonia. Top, 23 inches . Middle, 23^ „ Bottom, 23| „ Average of 5 ft. 10 in. . 1 Gallons. 32-9 41^0 27^0 Sp. Gr. •877 •877 •875 Lbs. (Lab. Tube). 12-8 110 12 33-6 -876 12-1 In the Broxburn field it varies in quality. At one place at 102 fathoms, when tested foot by foot, it gave 22-7, 27-9, 22-7, 18-5, 22-0, 20-0, 12-8 gallons. At Pentland, at No. 4 level, a section yielded — 8 iiiclip.s, Plain Shale ( Bottom) 4 9 H .. 6 ,, „ \ 2 ,, Ril) / 13 ,, Curly Shale 3 „ Ril) \ 12 ,, Curly Shale/ Average of .'i ft. Q\ in. Shale. Oil. Sp. Gr. 2-006 1-786 1-921 1-999 Galls, per Ton. 21-04 36-90 ■29-10 23-27 Sp. Gr. -S93i -89U •8891 •886| S. Vt. 91° F. 92° ,, 93° ,, 92° „ 2-262 16-82 -88.H 94° ,, 1-906 34-36 -881 95° ,, 1 2-079 22-98 -885 94° ,, 25-6 •886 93 -4° F. Sulphate of Ammonia. Lhs. jierTon. 2017 23-10 25-59 '24-54 22-04 24-87 25-28 24-0 10 150 Chemistry of the Oil- Shales. At Pentland, at No. 7 level, and therefore deeper than the previous section, a section gave — 2 feet 4 inches (Bottom) . 2 „ 2 „ ,, 6 ,, 1. „ ,, Curly Average of 6 ft. Shale. Oil. Sp. Or. Galls. Sp. Gr. S. Pt. 1 1-830 29-02 •880 89°?. 1-733 42-17 •875 87° „ 2-298 14-58 •876 90 r,, i 1-823 33-00 •870 91° „ , 32-65 •876 881°., Sulphate of Ammonia. T.bs. 22-90 21-84 23-54 25-68 23-06 At Pentland, at the extreme depth at the end of the working road — 13 inches (Bottom) Plain Shale . 15 ,, Curlv, partly. 15^ ,, Plain . 15 ,, Curly, partly. Average of 4 ft. lOt in. Shale. Oil. Sp. Gr. Galls. Sp. Gr. S. Pt. 1-996 25^77 •885 96° F. 1-687 46 ^32 •889 96i°„ 2-120 21^15 •883 94 r,, 1 ^945 34^83 •884 98° ,, 31^35 •885 96° ,, Sulphate of Ammonia. Lbs. 20^60 28-06 20-07 20-33 22-0 The average yield at Pentland for some years was 28i to 29 gallons of crude oil and 26 to 28 Ib.s. of sulphate of ammonia per ton, in the Young and Beilby retorts. In the laboratory retort of large size an average of 30 gallons was obtained. The yield of paraffin scale from this seam was very high : 15 to 16 per cent, on the crude oil in laboratory analysis. Of total products from the crude oil it gave 72 per cent, in the works. A seam, lower than the Dunnet Shale, v/hich crops out near Pent- land Works, tried in one-foot sections, amounting to 12 feet, gave the follo^ving results : — Shale. Oil. Sul])haie of AniiiiKnia. ■ Sp. Gr. Galls. S].. Gr. S. Pt. Lbs. 1 1-841 32-59 -88f) 91f F. 24-18 2 1-773 30-40 -888 ^H° „ 26-72 3 2-092 17-7G -885 911° „ 20-11 4 2-100 13-34 -882 92° „ 19-73 5 2-238 8-71 •883 9or „ 20-02 6 2-128 17-24 •878 92° „ 20-13 7 2-099 17-22 -881 9U' » 21-71 8 2-210 7-07 -878 90° „ 21-30 9 2-282 2-45 •881 81° „ 20-18 10 2-447 1-94 •887 81i° „ 17-82 11 2-303 8-02 -884 89° ., 17.84 12 2-443 2^18 -880 92i° „ 13.89 Yield of Crude Oil and Sulphate of Ammonia. 1^1 At Oakbank the Dimnet Shale, when divided into two parts, yielded — Top portion, 3 ft. ins., Sp. C4r. of Shale, 1-8534, 32-80 gals. Crude Oil per ton. Bottom „ 2„ 8 „ „ „ 2-0845, 21-60 „ Nitrogen, 0-629 per cent. 15. Oahhank Neio Shale, 8 feet 6 inches, gives 20"62 gallons of crude oil, and contains 0-548 per cent, nitrogen. 16. Camps Shale at Duddingston gives 18-67 gallons of crude oil per ton. At Raw Camps it gave 22 gallons. The Pumpherston or Drumshoreland seams, lying about 135 fathoms below the Camps or Burdiehouse Limestone, are characterised by a high vield of ammonia, with about 20 gallons of oil. 17. No. 1 or Pumpherston Jubilee Seam. — In the works retorts it gave 20-8 gallon.; of crude oil ; sp. gr. -883. Setting point 81, and 53-75 lbs. sulphate of ammonia. In laboratory tube 7 feet at one place gave 17-2 gallons ; sp. gr. "886, and sulphate of ammonia 30 lbs. A section at south border of Holmes estate gave, foot by foot, by laboratory tube — Oil Sulphate of Ammonia. Galls. Sp. Gr. Lbs. 1. Top 25-1 -889 17-9 2. 20-0 -886 18-6 3. 17-5 -893 21-7 4. 19-8 -883 14-7 5. 19-4 •882 14-7 6. 27-9 -888 22-4 7. 24-1 •887 13-7 Average o f 7 ft 22-0 170 18. No. .V Pumpherston or MayhricJc Seam. — At one place at Roman Camp it gave 16"6 gallons of oil ; sp. gr. -875, and 32-4 lbs. of sulphate of ammonia (lab. tube). 19. No. 3 or Pumpherston Curly Seam. — Tried by itself in works retorts it yielded 29-2 gallons in one trial, which is unusually high for this seam, 2r5 gallons in another. Sp. gr. -874. Setting point 90'^ F. ; 52-6 lbs. in one case, 67 lbs. in another, of sulphate of am- monia. A section of 4 feet from south border of Holmes estate, tried foot by foot, in laboratory tube gave — ; [Tabli? 152 Chemistry of the Oil-Shales. Oil. Snl[)liate of Am moil ia. 1. Top 2 3 4 Average Galls. 294 173 25^6 22-1 Sp. Gr. •887 •880 •880 •881 Lb.s. 167 18-0 28-0 24-0 23^6 21-7 A section at the greatest depth, No. 15 level, gave, foot by foot, in laboratory tube — Oil Sulphate of Ammonia. Galls. Sp. Gr. S. Pt. Lbs. 1. Top . 15^93 •878 79° 42^2 2 24^76 •878 79° 35^87 3 15-56 •886 78° 44-31 -4. . . IM •888 79° 44-31 5. . 12-3 •888 78° 42-2 6 — Average of 6 ft. . 8-48 •888 78" 42-2 14-7 41-84 There is a thin stratum near the top of this seam containing fisli remains which gave 35^16 gallons. 8p. gr. -868. Setting point 87. Sulphate of ammonia 21 • 7 lbs. (lab. tube). 20. No. 4 or Pumpherston Plain Seam. — In works retorts it gave by itself 27 gallons of crude oil and 70 lbs. of sulphate of ammonia. A section, foot by foot, near south border of Holmes estate, gave in laboratory tube 11-7 to 30-9 gallons of crude oil and 15 to 32 lbs. of sulphate of ammonia. A section at greatest depth, from No. 15 level, yielded, foot by foot, 9 to 26 gallons and 36 to 45 lbs. respectively. 21. No. 5 Pumpherston Wee or Under Shale. — A section of 5|- feet, taken in five equal parts, gave in laboratory tube — Oil. Sii]|iliate of Aiiiiiioiiia. Galls. Sp. Gr. S. Pt. Lbs. 1. Top . 8-48 •884 80° 33^06 2 14-13 •885 78° 29-86 3 31-4 -883 73° 23-53 4 23-1 •884 75° 26-13 5. . . . . Average, 5 J ft. 12-48 •876 78° 26-66 18 29 Analyses of Scottish Shales. 153 Sections taken from layers between the seams yielded 6 gallons of oil and 30 lbs. of sulphate of ammonia. A section stretching from the No. 4 or Plain to No. 5 or Wee Seam, taken foot bv foot going downwards, gave 17"78, 13"44, 14:"51, 11-12, 12-51, 5-41," 5-22, 5-80, 5-86, 13-36, 5-15, 5-31, 5-5-3, 11-32, 24-80, 23-87, 1232, 16-68, 7-77, 10-72 gallons of oil, and 33-76, 33-76, 33-76, 33-76. 29-54, 25-84, 25-32, 27-68, 31-56, 31-56, 31-64, 33-7, 33-7, 28-48, 23-20, 22-78, 22-98, 23-21, 35-84, 27-43 lbs. of sulphate of am- monia respectively. A section of 7 feet tried between the No. 1 or Jubilee and No. 2 or Maybrick Seams gave, foot by foot, beginning at the top, gallons per ton 80, 96, 16-3, 7-0, 11-8, 11*8, 8-0, and sulphate of ammonia corresponding, 26-0, 32-5, 28-4, 25-0, 31-2, 26-3, 25-5 lbs. per ton. Sp. gr. of oil -870. Setting point 69° F. Some companico have worked as shale a considerable proportion of the intermediate strata between the recognised seams. The following analyses of Scottish shales are by Messrs. Mingaye, White & Greig, of the New South Wales Department of Mines La- boratory, and are quoted from the " Memoirs of the Geological Survey of New South Wales : The Kerosene Shale Deposits of New South Wales," by J. E. Carne, F.G.S. These have been arranged according to their geological positions from above downwards, and the seams are numbered as in previous chapters. [Table l54 dh'emistry^ of the Oil-Shales. < o o < 9. «9 ceo 3 "a. I— t r±. ei r2i A » 1 ^ 21 = ' o <« -7Hg50^7-'7ip'>l i> M CO o o i.o crs 00 I- o-i o CO o o o cc (31 -t< I- CO o CTpR^prrC^(>ir-CCp00prH7ipp>CCC7-'CO00 owiyioi— ir^i-^oooi— 1'-^'— I'—'OooO'— it-to ooooooooooooooooooooo ooopoooppcppppppppppp ooooooooooooooooooooo ooooooooooooooooooooo t^i— it^0i'#(NCMi0fNOl^'?ir-Ot^t-I^C0tMOO rH 1^ 00 P p p p ?>1 p 1^ r;^ P 7-1 7-1 I^ ffl I- 00 r-H CO CO 05 60 00 ih M -^ -t< r^ -^ o o --^ >'>i -^^ ipc07f'p'^l_--pl;^p7t*pcOQ0fO--t'p 6o!X)n T-l o ■^— I (M CO CO lO ri- t^ (M CM -* C t^ t~ O fM ^1 fM I^ iC O CD(r>CDOC5'^Ci'l*. r-H (M . 7) • • 00 • ft "rt " " 5 S m „ rly SI ain SI ee Sh; EhPhSOe^ W PhW ^ fi Cm ^ 6S^ O) « ri2-^ •7; ^ ;h ^ ^ r^ to p -'^ "o w ro --< sj 1 — o tn cl,' t» f3 J_''. ' - >i (S G ? »- c3 1) — o ,. to " G p:5 i-H CO rt< lo CD :;c:5 o -^ co •* Analyses of Crude Oils. 155 2. ANALYSES OF CRUDE OILS FROM VARIOUS SHALES. From the Upper Coal-Measures and Carboniferous Limestone- Aunick Loelge, Ayrshire. Blackstone, Renfrewshire. Leveuseat Shale — (Which gave in Works Retorts 34 Gallons Crude Oil). CniJe Oil, Sp. Gr., -893 *S. Pt., 81i°F. Naphtha Buruiug Oil, Sp. Gr., -810| Lubricating Oil, ,, -870 Paraffin scale,! M. Pt., 110°F. Bottoms - Total Products . Loss iu Refining . 15^92% 41-37,, 12-91,, 1-06,, Sp. Gr., -909 S. Pt., 78°F. Sp. Gr., -S07i 23-96% •887"" 29-76,, M. Pt., 113°F. 9-07,, 1-27,, 64-06% 35-94,, Sp. Gr., -873 S. Pt., 67°F. Sp. Gr., -730 2-54% -810 38-00,, ->*85 24-20,, M. Pt, 120°F. 6-50,, 71-26% 28-74,, 71-24% 28-76,, Torbaneliill mineral gave 44 per cent, of crude oil, and 1 to IJ per cent, of crude paraffin. Distilling the crude oil in the laboratory, 100 parts by measure and '890 sp. gr. gave after distillation 90-4 per cent., sp. gr. "SGI. After treatment with 5 per cent, brown vitriol there was 80*4 per cent., sp. gr. '850. After caustic soda treatment there was 77"5 per cent., sp. gr. "844. We may compare these losses with a modern crude oil — Torhanehill Mineral Crude Oil. Philpstouu Crude Oil for Comparison. Sp. Gr. of Original Oil . . -890 Loss Ly 1st Distillation . . 9-6% Sp. Gr., -861 Loss by 5% B. v. . . . 10-0,, „ -8.''.0 Loiss by excess Caustic Soda . 2-9,, ,, -844 Sp. Gr., -873 6-22% „ -859 13-92,, „ -842 1-18,, „ -843 Loss by 1st Distillation and) oo.ro/ Treatment. / ^"^ ^/° 21-32% Mr. Iltyd Redwood | gives the yield of solid paraffin from Boghead coal as 22 lbs. per ton of coal, or 0'98 per cent. ; about 2 per cent, on the crude oil. * S. Pt. = Setting Point. t M. Pt. = Melting Point. X "Minora! Oils .and their By Products." p. 6. [Tahle 156 Chernisirj/ of the Oil-Shales. H o o o ^ c r » z^ ^ ^ r O fc ci Ci 1 - cc >.o ,~ o • " o •-H i-H 7t" o ^~. ?^ 00 f-H o >» 00 00 1^ Al -^ (ii ^ oi 00 o o c CO 1—1 1- fN '"' fa ^ o rO -. <" 00 i^ i'- ■^ « 6 o 6 o (M f— ( o eo r— 1 ;-i fa" r^ o E I— . , ^i; pq 00 <% o ^ o fa Ci o -t o ,^ o o ' 'P ^^ oc p o o i- o cc ,1-i o 6 o r— 1 cJ CN cq I-H o -S :=: ^O X' O ^ O 5 rP St! c3 X h^ O - ^ 5P 1 -J - ;^ -J-. rr; -^ 'S •"* ^ •TT O ;^ m ^J V2 o General Chemistry of the Shales. 157 Analyses of Crude Oil from the Different Seams. Bioxburn Seam. liroxburn Seam, at Broxburn. In Hender- son's 1873 Retort. Broxburn Seam, at Broxburn. In Hender- son's 1889 Retort. Broxburn Seam, at Pentland. Young & Beilby Betort. Crude Oil, Sp. Gr. . Setting' Pt. Naplitlia, Sp. Gr., -730 . Burning- Oil, ,, -810 . Medium Oil, ,, "840 . Lubricatinif Oil, ,, '865 . ■885 . Solid Paraffin .... Bottoms Total Products Loss in ReCniii;,' . •865 74^'f. 3-30;^ 40-59,, 0-70,, 0-70,, 16-13,, 10-02,, -871 M. Pt.', 116'F. 83°'P. 1-88% 30-23,, 8-41 „ 17-24,, 11-51,, 00-27,, 30-73,, •884 •807 1 -880 M. Pt., 115°F. S9°F. 19-40% 34-02,, 14-56,, 2-47„ 71-50,, 2S-50,, 70-54,, 29-46,, Dunnct Seam. Dunnct, Pentlaud. Dunnct, Broxburn. Duniiet, Queensferry. Crude Oil, Sp. Gr. . SettintfPt. Naphtha, Sp. Or., -740 . Burning Oil, ,, -810 . Medium Oil, ,, -840 . Lubricating Oil, ,, -865 . -885 . Solid Paraffin .... Bottoms Total Products Loss in Refining . •870 ■778 -a07 } -876 M. Pt., 114°F. S4°F. 4-65% 21-14,, 31-01,, 16-82,, 1-83,, 75-45,, 24-55,, •S72 M. Pt.','ll5'F. S9"f. 1-36% 31-60,, 4-86,, 10-30,, 10-08,, 10-52,, •876 M. Pt.','ll5°F. 93°'f. 2-37% 31-98,, 3-20„ 12-15,, 11-13,, 11-59,, 68-72,, 31-28,, 72-42,, 27-58,, Pumpherston Seam. Mixed from Holmes. Mixed from Pumpherston. Mixed from Roman Camp. Crude Oil, Sp. Gr. . ,, Setting Pt. Naphtha, Sp. Gr., -730 . Burning Oil, ,, -812 . Medium Oil, „ -840 . Lubricating Oil, „ -865 . ■875 . •885 . Par. .Scale .... Total Products Loss in Refining . -867 M. Pt.,'il3i°F. 75 'f. 1-71% 36-28,, 2-76,, 1-38,, 3-76,, 14-13,, 9-83,, -876 M. Pt.','ll5°F. 73°'f. 0-68% 30-53,, 1-78,, 8-93,, 18-33,, 11-06,, -877 -740 •810 ■840 ■865 ■885 M. Pt.Vll6"F. S4°F. 1-86% 28-79,, 9-18,, 1-88,, 18-37,, 10-04,, ■■ 69-85,, 30-15,, 71-91,, 28-09,, 70T2„ 29-88,, The results of crude oil analyses are not absolute, so that different analysts obtain somewhat different figures for the same oil. 3. GENERAL CHEMISTRY OF THE SHALES. The Chemical Composition of Shale. The ultimate coinposition of the organic matter in the Broxburn seam -with dried shale (which had contained 2" 72 per cent, of moisture) was — carbon, 19' 12 per cent. ; hydrogen, 2" 94 per cent. ; nitrogen, 0*54 per cent. The nitrogen, if it were possible to convert all into ammonia, corresponds to 57 lbs. of sulphate of ammonia per ton, or 2" 55 per cent. The 'proximate composition of shale, not dried, by ignition in a closed crucible wa ; — volatile matter, 25*5 per cent. ; fixed, 74*5 per cent., of which 4*95 was carbon and 69*55 ash ; sulphur by Carius's method, 1'44 per cent. 158 Chemistry of the Oil-Sliales. The nitrogen of four pieces of the Broxburn seam taken at random from the breaking machine amounted to 0*94 per cent., 0'61 per cent., 0"52 per cent., and 0"66 per cent., and corresponding to 99, 04, 55, and 70 lbs. respectively, of svdphate of ammonia per ton. A good fragment of the Broxburn seam gave in a small glass tube 42 gallons of crude oil to the ton or 1G"5 per cent. ; sulphate of ammonia, 2G"88 lbs. per ton, or 1-2 per cent. The nitrogen was accounted for as follows : — Total Nitrogen in the Shale = 303 per cent, of Sul. Amm., or 6787 lbs. per ton. In the Crude Oil . . = 0-76 „ „ 1711 „ In the Ammonia Water . = \'2 „ „ 2688 „ „ In the Spent Shale . .=0-86 „ „ 19-27 „ Unaccounted for . .=0'21 „ „ 401 „ „ The portion unaccounted for was probably nitrogen that had been converted into the elementary state by the high temperature. No steam had been used in the distillation. The Broxburn seam at Mid-Calder contained 0'70 per cent, of nitrogen, equal to 74 lbs. sulphate of ammonia per ton of shale. The oil contained nitrogen equal to 15 lbs., the water equal to 36 lbs., and the spent shale and loss equal to 23 lbs., to make up the total of 74 lbs. of sulphate of ammonia (Beilby). A piece of the Broxburn Curly Seam gave 0*96 per cent, nitrogen, equal to 101 lbs. sulphate of ammonia per ton. The Broxburn seam at Pentland contained 24 per cent, volatile matter and 76 per cent, spent shale. The volatile matter was made up of 10-6 per cent, oil, 7-5 per cent, water, and 5*9 per cent, gas and loss. The spent shale consisted of 5*2 per cent, carbon and sulphur, and 70"8 per cent, mineral ash. The crude oil was equal to 27 gallons per ton. The total nitrogen was equal to 48 lbs. sulphate of ammonia per ton. It was distributed in the products : as sulphate of ammonia, got from the water, 23 lbs. per ton ; nitrogen, in the oil, equal to 12 lbs. sulphate of ammonia per ton ; and in the spent shale and loss, 13 lbs. Mr. Hope, Chemist to the Oakbank Oil Company, kindly sends the following nitrogen determinations of Oakbank Shales : — Big shale, 0'720 per cent, nitrogen ; curly shale, 0'575 per cent.- ; M'Lean's shale (or Broxburn seam), 0'646 per cent. ; Dunnet, 0'629 per cent. ; and new shale (8 feet 6 inches thick, giving 20*62 gallons crude oil per ton), 0"548 per cent, nitrogen. In the Dunnet seam at Pentland 25' 72 per cent, of volatile matters were obtained, and 74*28 per cent, of spent shale. The volatile material consisted of 12*70 per cent, oil, 6*47 per cent, water, and 6*55 per cent, gases and loss. The spent shale consisted of 8*37 per cent, carbon and sulphur, and 65*91 per cent, mineral ash. The crude oil amounted to 32*27 gallons per ton. The total nitrogen was 0*49 per cent., equivalent to 51*74 lbs. per ton. It was distributed in the products thns : as sulphate of ammonia from the water, 22 lbs. per ton, and nitrogen in the oil equal to 15*0 lbs. ; and in the spent shale and loss equal to 14*74 lbs. In a sample of a Pumpherston seam at Roman Camp the total nitrogen was 1*72 per cent., equal to 182 lbs. ammonia sulphate per ton. A small laboratory tube, with super- heated steam passed in, gave 73 lbs. of ammonia sulphate per ton, with the same sample of shale. General Chemistry. 159 Sulfhur. — The total sulphur in different samples of the Broxburn seam, 1"58 per cent., 1"32 per cent., r4. Sulphur as Sulphate. Total Sulphur. Broxburn Seam .... Jubilee Seam ... Curly (Pumpherston) Plain „ ... Wee „ ... Per Cent. 0-15 0-15 0-19 0-12 0-05 Per Cent. 1-32 1-17 1-88 1-79 1-43 A sample of Dunnet Shale from Burntisland gave total sulphur 1*32 per cent. Another sample of it gave TGS per cent, sulphur. The ash determined in the spent shale from Broxburn seam after distillation in the Henderson (1873) retort was — Silica, 49* 72 per cent. ; ferric oxide, 16*8 per cent. ; alumina, 18*8 per cent. ; lime, 2*4 per cent. ; magnesia, 2'2 per cent. The carbon, alkalies, and sulphiu-ic anhydride were not determined. Another determination of the spent shale from the Broxburn seam gave — Moisture, 1*07 per cent. ; carbon, 5'38 per cent. ; silica, 55*97 per cent. ; alumina, 3r21 per cent. ; ferric oxide, 2"84 per cent. ; lime, 0*59 per cent. ; magnesia, 1*87 per cent. ; soda, 0-62 per cent. ; sulphuric anhydride, 5"0G per cent., making a total of 104'61 per cent. Dr. Mills (" Destructive Distillation," 4th ed., p. 50) gives the com- position of ash of good average shale as — Soluble in water (containing 0"92 sulphuric oxide, SO3), 8*27 per cent. ; silica, 55"60 per cent. ; ferric oxide, 12"23 per cent. ; alumina, 22' 14 per cent. ; Ume, 1*55 per cent. ; magnesia, trace ; sulphur, 0*94 per cent., making a total of 100"73. Total sulphur in shale, 1-80 per cent. Total sulphur in ash, 1*31 per cent. The solubility of shale in solvents varies with the solvent. Brox- burn shale with ether yielded 1*66 per cent, soluble, with shale motor spirit r79, with carbon disulphide 2*04, with motor spirit and ether r95. The following results are from a mixture of light shale spirit and ether, half and half, in a Soxhlet apparatus. Broxburn Shale ...... 1'95 per cent. Sohd bitumen from Dunnet Mine, Broxburn . . 98"75 ,, Albertite from Dunnet Shale, Dunnet Mine, Broxburn : 454 ,, Shale, New Brunswick ..... 2"33 ,, Hard or brittle albertite. New Brunswick , . 504 ,, Maltha, New Brunswick ..... 36-82 „ The soluble matter on evaporating off the solvent was in general like native petroleum. The Torbanehill Mineral. As already indicated, the Boghead or Torbanehill Mineral was the first substance used in Scotland for paraffin oil making, and torbanite IS by far the best yet discovered for that purpose or gas making. There have been several important lawsuits in this country and 160 Chemistry of the Oil- Shales. one ill Germany to determine the question whether torbanite should be regarded as a coal or shale. No doubt, in the strict scientific sense, it is a very rich shale. It differs from coal in having a larger proportion of hydrogen in its composition, and in not leaving a coke on distillation. In ordinary gas coal the proportion of carbon to hydrogen ii 100 to 10. With Torbanehill Mineral it is 100 to U. When heated in a retort or covered crucible the hydrogen unites with the carbon so as to carry it away as vapour or gas, and the residue left is not a coke, such as coal would give, but ash with a small pro- portion of carbon — a spent shale, in fact. The volatile products contain a larger proportion of hydrogen atoms than 1 of carbon to 2 of hydrogen. The Torbanehill Mineral is of a brown or nearly black colour, having a yellow or fawn-coloured streak without lustre, and sub- conchoidal fracture. It shows parallel banding by splitting, and, although homogeneous in appearance in the fresh state, shows strati- fication when spent in the retort. It is non-electric. It is a mass of carbonaceous matter Avithout structure mingled with stems or roots of trees showing structure ; and the fossils were found throughout the bed and not merely on the surfaces of seams, as is general with coal. It contained impressions of Sigillaria and Stigmaria, and the fireclay under it, about 5 inches thick, contained Stigmaria (E. W. Binney, F.G.S., of Manchester, in " Ure's Dictionary of Arts, Manu- factures, and Mines," 7th ed., I., p. 408). The microscope showed the scalariform tissue of tree ferns (Prof. J. H. Balfour, in Gillespie v. Russel, Session Papers, 1854, p. 486 ; Pharm. Journ., 1853-4). There were no fish remains. AVhen being mined or broken up it had a gaseous smell, but afterwards, when breathed on, it had a clayey odour. Pounded and moistened and worked with the hand, it was cohesive enough to make a brick. It was very indestructible, and did not deteriorate much with weathering. The seam itself was covered by a close compact roof of cementstone and shale, perfectly water- and air-tight. This covering had perhaps some connection with the formation and preservation of the mineral after submergence (" Ure's Dictionary," 7th ed., I., p. 409). Near basalt dykes it became a soft, sticky, brown substance resembling melted india- rubber. In the vertical retorts it sometimes stuck as a buttery mass, and would afterwards fall through the vacancy that had formed, into the water lute below, and when taken out was plastic like putty. Tested in the laboratory, it takes fire readily, splits, but does not fuse, and burns with an empyreumatic odour, giving much smoke, and leaving a considerable amount of white ash. Artists found the ash to be a most satisfactory and imperishable base for colours for fresco-painting. The mineral varied throughout the field, and in different layers at the same place. Sp. gr. ri7 to TSIG. Dr. Fyfe found volatile hydrocarbons 66"9 to 70*1 per cent. ; fixed carbon, 6"6 to 16'3 per cent. ; ash, 12"8 to 23-2. The specific gravity was not in propor- tion to the ash. Graham found 22 per cent, ash, with 1"28 sp. gr., and 30 per cent, ash, with 1*22 sp. gr. (Gillespie v. Russel). The combustible part is therefore variable in its nature. Johnston found the black variety to have 21*3 per cent, ash, and the brown 24" 3 per cent. ash. In distilUng, the distillate was slightly acid at Torhanehill Mineral. 161 the beginning, becoming alkaline further on. A sample mined fifty years ago was tested recently in the laboratory with the following results, per cent. : moisture O-O-l, volatile matters 70" 63, fixed cent. : moisture carbon, 7-94, and ash 21-39. The ultimate composition is (Gillespie v. Russel, and " Ure's Dictionary of Arts, Manufactures, and Mines," 7th ed., I. 408) : — Stenhouse. Anderson. 'F^ fe. Graham. Carbon 65-72 64-02 60-25 63 Hydrogen . 9-03 8-90 8-8 9-1 Nitrogen . 0-72 0-55 1-533 1 Sulphur . 0-50 0-13-0 Oxygen . 4-78 5-66 3-62 Ash .... 19-75 20-32 25-6 Other analysts give total carbon 60 to 65 per cent. ; hydrogen 7^ to 9 per cent. ; oxygen 4 to 6 or 8 per cent. The ash, according to Stenhouse, contained in 100 parts, silica 58-51, alumina 33-65, sesquioxide of iron 7-0, potash 0-84, soda 0*41, and traces of lime and sulphuric acid. Hofmann found in 100 parts, silica 56-7, alumina 36-2, sesquioxide of iron 3-2, lime 1-3, magnesia 0-4, potash, 1-2, soda TO, with traces of sulphuric acid (Gillespie v. Russel). Anderson found silica 56-09, alumina 40-04, peroxide of iron 3-24, lime 0-34, magnesia 0*46, total 100-17 ; no sulphuric acid. In the Torbanehill Mineral we have from 20 to 30 per cent, of clayey matter, mixed with carbon compounds of complex constitu- tion, which are not soluble in benzene, turpentine, carbon bisulphide, or petroleum spirit, and they are therefore not of the nature of petro- leum, resin, or true bitumen ; at any rate, only a very small propor- tion is soluble. It gives petroleum-like products by distillation at a gentle heat. Throughout all coaly or bituminous strata in all countries there are resinous-looking bodies known as spores. Under the micro- scope the combustible matter of the Torbanehill Mineral is described as having rounded particles looth f'f> ^his^^ c)f an inch in diameter, with radiated internal structure. Redfern describes the masses as yellow, rounded and flattened above and below, o^ioth to h^o^^ of an inch in diameter, set in a dark-brown matrix. He found also yellow particles distinctly angular and polygonal, uniformly two^^^ of an inch across. The yellow spots in v(M-tical sections appeared striated, while horizontal sections showed no striations. Torbanite shows more structure under the microscope than cannel coal. The French authorities, Bertrand and Renault, followed later by Professor Potonie of Berlin, have maintained that torbanite in general is made up of microscopic colonial gelatinous green algce: that these differ in different climates and circrun-taiices, the genus Pila characterising the northernhemisphere and Reinschiathe southern ; and that immense numbers of bacteria are present, especially micrococci. Professor E. C. Jeffrey, in the Proceedings of the American Academy of Arts and Sciences (vol xlvi.. No. 12), asserts that the thinner micro- scopic sections prepared by improved methods, reveal the presence,. 162 Chemistry of the Oil-Sliahs. not of algfo, but of spores of vascular cryptogams, and says that the spore structure is more pronounced in American and Scotch Boghead coals than in the bituminous schists originally investigated by Bert- rand and Renault. His method of working and the thinness of his sections enabled him to make serial sections of the one spore ; and he considers it beyond question that he has resolved, for instance, Pila scotica of the Scottish Boghead into spores of vascular crypto- gams, made evident by their possession of the triradiate ridge char- acteristic of tetrahedral spores. In the Boghead Coal, Dr. Aitken found spores of ferns in clusters, and the same in the Capeldrae seams and other coals.* Not^\'ithstanding these observations, microscopical appearances are somewhat indefinite, and there seem to be investigators who think that, after all, the carbonaceous matter may yet be proved to be of inorganic origin (A. C. Seward in " The Kerosene Shale Deposits," by Carne, p. 64). Some authorities are of opinion that the carbon compounds are in combination with the clayey matter. The com- pound present has been compared to the combination that takes place between Florida fuller's earth and the unsaturated hydro- carbons of petroleum, got by filtering petroleum through that earth ; but the hydrocarbon can only be got from the Boghead mineral by distillation, while the fuller's earth gives up its hydrocarbon quite freely when brought into contact with hot water. The combination, so far as it exists, is of a closer kind. James M. Petrie, D.Sc, has examined the oil from the Torbanite of New South Wales, in the Chemical Laboratory of the University of Sydney ( J.S.C.T., 1905, p. 996). The richest Joadja Creek Shale analysed by W. A. Dixon has — Carbon Hydrogen Oxygen Nitrogen Sulphur Ash 75-32 1205 5-49 0-28 0-31 6-55 10000 The ash has percentage composition SiOjj 77-12; AI-.O.., 20-14 ; FeaO... 0-76 ; CaO 0-30 ; I\IgO 0-45 ; P2O5 OOo. Vanadic oxide was found by Mingaye 0-01 per cent. In tlie ash of Scotch Shale as much as 0-12 per cent, has been found. The ratio of volatile to fixed carbon in the richest N.S.W. torbanite is 16 to I, ash 6 per cent., while in torbanite of Scotland the ratio is 8 to 1, aiid ash 20 per cent. Sp. gr. of N.S.W. average shale is r2, the richest TOOS. There is soluble in ether O'S per cent. Distilled in the works the crude oil sp. gr. is -9035, colour dark brown, with greenish tint by reflected light. Of solid paraffin 9 per cent. * Information as to facts and theories, both old and new, may \e found in " The Kerosene Shale Deposits of New South Wales," by J, E. Carne, F.G.S., m.ore particularly referred to at p. 153 of this chapter. (See pp. 14, 60, 63, 72.) E. Bertrand and B. Renault have each written many papers. Renault has " a monumental work," " Sur Quelques Organismes des Combustibles Fossiles." Bulletin de la Societe de r Industrie Minerale, Series 3, Tome 13, 4me. Livraison 1899 ; Torae 14, Ire. LivTaison, 1900. Bertrand recently described the views of Renault and himself in " Notions Nouvelles sur la Formation des Charbons de Terre," Remiedu Mois, 3, No. 15, pp. 323-41, Paris, 1907. H. Potonie, "Die Entstehung der Steinkohlc und verwandter Bildungen cin.schliesslich des Petroleums." Vierte verbesserte und crweitcrte Auflage. Beilin, 1907. Origin of Kerogen. 163 is got in cold weather. The crude oil has composition per cent. : carbon 86-93 ; hydrogen 11-96 ; nitrogen by Kjeldahl method 0-58 ; sulphur 0-373. The crude oil is a mixture chiefly of paraffins and defines. The' lightest distillate contains 70 per cent, olefines. As the boilins point rises the olefines gradually decrease ; at 280° C. they disappear. Oil distilling between 280° and 400° C. con- sists almost entirely of paraffins. Benzenes and naphthalene are in the crude oil in small quantities ; also phenols in notable quantity and pyrrol and chrysene are present. The following notes on New South Wales Shale have been kindly sent me by Mr. John Woodrow, London, who had practical experience in refining the oils of these shales : — Hartley Best Shale. (Export.) Hartley Re- torting Shale. Capertee Re- torting Shale. Capertee Splint. Moisture Vol. matters . Fixed Carbon Ash . . . Sulphur Sp. gr. of Shale 1-02 75-2 15-3 8-48 0-85 45-32 31-27 22-56 1-15 46-52 32-13 20-20 1-4 28-9 0-3 63-4 100-0 100-0 100-0 100-0 0-3 1-008 0-41 1-263 0-25 -0-68 1-218-1-497 At Hartley there were 3^ to 4 feet of rich shale with 10 inches or so of inferior shale below, which, having no parting, had to be removed by axe. At Capertee there were 5-1- feet of good shale -vrith 4 inches sijUnt below and 6 inches above, besides other shale and splint. Hartley best shale distilled in horizontal retorts without steam produced 120 to 160 gallons of crude oil per ton. Sp. gr. -855. S. pt. 58° F. (31.6° C). Pale colour, sweet smell and easily refined. Capertee best shale in horizontal retorts -svithout steam yielded 90-95 gallons crude oil. Sp. gr. -866. S. pt. 58° F. (31-6° C). A good oil, but inferior to Hartley. The horizontal retorts were made of boiler plate 6' x 6' x 2' 2", and it took three days to work off a charge. Hartley Shale withdrawn from the retort and cooled when half distilled was like a piece of stiff rubber. The rich shales mentioned were sold for gas making. Poorer shale at Hartley above and below the rich seam was retorted, yielding 44-9 gallons crude oil, sp. gr. -890, and S. pt. 70° F. (38° C), sulphate of ammonia 3] lbs. TJie crude oil yielded per cent. : spirit, (-720 to -780), 4-02 ; burning oil, (-800), 10-2 ; gas oil, ('850 to -860), 16-98; blue oil, ("900), 40-77; crude paraffin scale, 4-41; coke, 3-59. Total products 7997, and loss in refining 2003. Coals used at retorts 6-29 cwt. per ton of shale. Capertee retorting shale, in vertical retorts, produced 48 gallons crude! oil, sp. gr. -900-5, S. pt. 72° F., ammonium sulphate 10-5 lbs. per ton. The marketable products, pei-centage on crude oil, Avere : snirit, (730-60), 1-2 ; gas oil, (-850), 58-0; heavy blue oil, (-935), 16-4; paraffin scale M. pt. 1-22-3° F., 4-1; products 797 and loss 20-3. At Capertee the splint was kept apart from the retorting shale, as the distillate from it is a sticky resinous substance which blocks up the condenser pipes, and gives a persistent yellow colour to the solid paraffin, making it impossible to refine to Avhiteness. The shale output in N.S.W. in 1908 was 46,303 tons. Two great companies liave now taken up the manufacture and are erecting modern retorts and refineries. Nature and Origin of Kerogen in Oil-Shale. We will now proceed to consider the nature of kerogen * — the valuable material in oil-shale — and its probable origin. * See p. 143 for definition of kerogen. 164 Chemist r>/ of the Oil-Shales. In the oil-shale, as in the Torbanehill Mineral, paraffin and paraffin oil do not exist as such : they are created by the de- structive distillation in the retorts. There is very little in shale soluble in petroleum spirit, benzene, carbon disulphide, ether, and such solvents. Our substance is therefore not of t!ie nature of petroleum or bitumen or resin. All hydrogen and carbon compounds produced by inorganic reactions are soluble in these solvents, and this makes it almost certain that kerogen is of organic origin. The material has probably been deposited, together with clay, at the bottom of lagoons, and has there been subjected to maceration and limited microbe action. Part would decompose and only what could withstand the water, &c., would remain. We can imagine a plant or plant-organ decaying and leaving only the wax or fat that was originally meant for its protective covering, or perhaps some resinous excretion or secretion. But this would give us materials soluble in our solvents, and might account for the origin of petroleum or bitumen, but not for kerogen. Some shales are largely made up of cntomostraca, and it is prob- able that the animal matter has in some cases been converted into kerogen. AVe can imagine kerogen being produced from any kind of organic matter by the action of microbes under special circumstances, the product being dependent on the microbe. Or, on the other hand, kerogen in some cases may be the remains of certain kinds of vegetable matter, like pine pollen or lycopod spores, perhaps little altered, the product being dependent on the nature of the original organic matter. Surmising that kerogen might be some such substance not much altered, we tried to make artificial shale. Dried Florida fuller's earth was taken, 75 parts, and lycopodium spore dust, 25 parts, to represent the supposed lycopodiaceous Lepidodendron spores from our forests by the lagoon, and the mixture v/as moistened and made into a brick with gentle heat. It was then broken up and distilled in a laboratory retort. Crude oil was obtained equal to 23"8 gallons per ton, sp. gr. •9.30, and setting point 35° F. (2° C), and sulphate of ammonia 3"3 lbs. per ton. It was found, however, that lycopodium dust, treated with benzene C^H^, Soxhlet fashion, gave up 21 per cent, in solution, which, on evaporation of the benzene, yielded a yellow-brown viscous oil. After thorough extraction of the oil in this way, the remaining insoluble matter of the spore dust was taken and made into a brick as before, and in the proportion of 25 per cent, of the original dust. On retorting, crude oil was obtained equal to 17 gallons per ton, sp. gr. •930, and sulphate of ammonia 1 lb. per ton. The crude oil, specific gravity and setting point, and the amount of ammonia agreed very well with the figures got from the Torbanehill mineral and the higher shales. Others have ascribed the organic matter in shale to lycopodiaceous spores, and it is quite reasonable to consider that such material contributed to some extent at least to the formation of the Tor- banehill Mineral and oil-shale. As peat gives paraffin products on distillation very like those of shale, it is probable that shale contains ordinary vegetable or organic matter that has undergone decay to substances of a humic acid nature, which have been rendered insoluble and preserved by chemical com- Origin of Oil-Shale. 165 bination with the metallic oxides of the clay or water, the alumina, lime, &c. Oil-shale, therefore, may be composed of (1) vegetable matter which has been made into a pulp by maceration in water and preserved by combining with the salts in solution as already mentioned ; (2) richer materials of many kinds, such as spores, which nature has provided with means for protection against decay ; and (3) a proportion of animal matter. In accounting for the differences between the different shales, and between shale and torbanite, &c., we must remember that during the deposition of the sediments, as the lapse of time was very great, the climate must have varied to some extent, and the algae and plankton generally of the lagoon must have changed also, together with the shore vegetation, producing pollen, spores and seeds. The differences and varieties may have arisen from changes in the proportion or nature of the humus, the spores, and the animal matter. And there are also the modifications produced by age, and the different conditions to which they have been subjected during their long history in the earth, such as warmth from depth or from proximity to intruded igneous rock. Again, shale may be considered as torbanite containing a larger proportion of earthy matter from its original deposition, or perhaps shale is simply a torbanite that has deteriorated with age. For, as already indicated, the crude oil diminishes and the ammonia increases as a general rule with the age of the shale. In old peat the proportion of nitrogen is sometimes, if not always, greater than in new peat of the same bog, owing to the nitrogen-free compounds decaying more rapidly than the nitrogenous compounds under the special circumstances. Recent plants subjected to destructive distillation yield a very acid distillate, peat less so, brown coal still less, while Torbanehill Mineral has a distillate slightly acid at the beginning and alkaline further on, while shale is very alkaline throughout. Hence the decrease of crude oil and increase of ammonia may partly be the result of age. No doubt part of the nitrogen is in combination in the kerogen,* and this part may through time have increased in proportion ; but the richness * The composition of the organic constituents of good average shale, repre- senting the kerogen referred to in this Memoir, is given by Dr. Mills, F.R.S. (Destructive Distillation, 4th Edition, p. 50) : — Carbon Hydrogen Oxygen Nitrogen Sulphur 25 27 per cent. 3-67 5-65 114 0-49 36-22 Part of the nitrogen and sulphur are no doubt in combination in the kerogen; but excluding the ash, nitrogen and sulphur, the percentage composition is — Carbon . . . . . .73 05 Hydrogen ...... 10-62 Oxygen ...... 16-33 10000 This corresponds to C^HjuO. The proportion here between carbon and hydrogen is ,100 carbon to 14-5 hydrogen. IT 166 Chemistry of the Oil-Shales. of the oldest shales in ammonia is more than we would expect from this cause alone. The common coals used as fuel in the works when subjected to low- temperature distillation in the laboratory retort-tube in the same manner as shale, in 1890, gave 21 to 31 gallons of crude oil per ton, and 8 to 11 lbs. of sulphate of ammonia per ton. The coke left in the retort was 57 to 62 per cent. The crude oils had a specific gravity heavier than water, 1-020 to TOGO. The following are examples : — Beiihar Tripiuy, No. 1, kept some time No. 2, „ ,, No. 2, fresh Falkirk Coal Co Walker & Cameron .... Crude Oil. Sulphate of Ammonia. Coke. ' 1 Gallons per Ton. Sp. Or. Per Cent. 31-37 1-040 9-5 56-23 24-63 1-051 8-6 56-86 24-3 1-020 10-3 60-2 •20-9 1-014 10-0 61-7 28-1 1-064 8-0 58-5 j Mr. Stoddart of Howden has kindly supplied the following figures regarding yields of oil from coal got by Dr. Penny about 1860. The gallons of crude oil per ton amounted to — Boghead 128, Wemyss 70-4, Methil brown 90, Methil black 52. Capeldrae 1st quahty 81, 2nd quality 63, Overton 64, Wellwood 46, Rochsoles 72, Auchenheath 78, Knight- wood 36. The specific gravity of the crude oil of Torbanehill mineral and the upper shales being higher than that of common shale, depends, no doubt, on the higher proportion of compounds of the benzene-ring type. The more ancient shales give a greater proportion of the chain or paraffin type of compounds. Petroleum from the ancient formations belongs to the simpler paraffin type, while from the more modern it tends rather to the more complex ringed type of compounds. Petroleura in "West Lothian Shale-fields. Minerals found in our shale-field are natural gas, liquid petroleum, asphaltum, elaterite, ozokerite, albertite and anthracite. As already mentioned, native petroleum was found near Broxburn in sedimentary strata about 10 fathoms below the Dunnet Shale. In 1886, in Xo. 5 or Sandhole pit, near the refinery, while cutting a level westward tlirough incHned strata, at the above-mentioned position, there was a constant oozing of petroleum and brine, together with a strong smell of gas. A well was made and the petroleum gathered at intervals for over a year. About 200 barrels in all were got. The. specific gravity of the oil was -830, the setting point (or highest temperature at which it congeals or ceases to flow) was 61° F. (16° C). It had a brown colour by transmitted, and green by reflected, light. Refined in the laboratory it produced — Naphtha, Burning Oil, Intermediate Oil, Lubricating Oil, Solid Paraffin. M. pt. 103° F. (.39-4= Loss in Refining Sp. gr. -700 5-0 „ -730 5-2 „ -80-2 341 -840 10-5 -865 16-7 12-5 16-0 1000 Petroleum in Oil-Shale. 187 The burning oil of this material had bromine-absorption 6" 5 per cent, against Russian burning oil 0, American burning oil 11 per cent, and shale burning oil 40 per cent., all tested comparatively. The brine that accompanied the petroleum had sp. gr. 1*095 (sea-water being r025). It gave 11,000 grains or 25 oz. of total solids to the gallon, or 14'4 per cent. The salts present were chlorides of sodium, potassium, calcium, magnesium, with trace of ferric chloride. Am- monium chloride was present in amount equal to O'Ol lb. per gallon. There was only a trace of sulphuric acid. Regarding the origin of this petroleum, it may be noted that all ordinary fermentations and decompositions on the surface of the earth are the result of microbe action ; and they may also be involved in the changes that take place in the strata below the surface. Kero- gen and petroleum may possibly originate from the same kinds of organic matter, but acted on by different microbes, soon after de- position or subsequently. It is highly probable that when the Coal- measures were laid down there was a much larger proportion of car- bonic acid in the atmosphere than now, which, on account of the power of this gas to absorb radiant heat, would produce the warm moist climate that generally prevailed in the Carboniferous period, and also from its solvent action would increase the salts in solution in the ocean and lakes, and influence the microbes. Petroleum everywhere seems associated with brine or salt from an ancient sea. The anti- septic action of the brine would kill off many kinds of microbes and give the advantage to others that would multiply and might thereby produce petroleum. In the locality of the Sandhole pit petroleum the Dunnet seam produces only about 12 gallons of crude oil, but no sill is known to be near enough to give the crude oil by high tempera- ture distillation, and the shaly strata seem too impervious to have had it intruded from a distance. In this case it is probable that the petroleum was not the product of high temperature distillation of the shale by the heat of intruded igneous rock, never far distant in this field. It is more likely that the brackish lagoon became charged with sea-water and was separated from the ocean. Concentration then took place, and the petroleum here, as elsewhere, was formed at a not very high temperature, after being deeply covered up. E. W. Binney {Proc. Manchester Lit. and Phil. Soc, Vol. III., p. 136) described petroleum from a peat bog, which he believed to be subject to infiltration of sea- water, thus probably giving rise to the circum- stances necessary for the production of the petroleum ; and there are other examples of petroleum from peat bogs. There would be no chance of the high temperature required for ordinary distillation in these cases, and we have here the specific action of definite microbes at ordinary temperatures. Even if the effect of the concentrating brine in an inland sea were to destroy all microbe life and leave the organic matter to pure chemical reactions, we might have products of destructive distillation in the depths of the earth, at far lower temperatures than we require in the laboratory. There is a general law to the effect thai reactions which take place instantly or speedily at a high temperature take place also at rapidly decreasing ratios as the temperature falls ; about twice as slow for a lowering of 10° C. (Ilolleman's " Inorganic Chemistry," p. 1()). In many cases the reaction has practically ceased for ordinary temperatures ; but in geological time the reaction tells 168 Chemistry of the Oil-Shales. particularly at the increased temperatures got deep in the earth. We may remember also, in this connection, the molecular and atomic mobility in solids, as shown, for instance, in metals. Distillation of Oil-Shale by Intrusive Igneous Rocks. The effect produced on oil-shales by the intrusion of igneous rocks depends on the proximity, the temperature and mass of the intruded matter, and the amount of water, with its cooling power, in the sedi- ments which are invaded. Specimens of Broxburn Shale were taken some distance apart from localities beneath the dolerite sill near New- bigging, about a mile N.N.E. of Uphall. Two samples gave low results, 23 gallons each ; but the other two yielded 31 gallons each, and the igneous rock may therefore have been further off. Again, near Drum- shoreland, a basalt dyke, about 100 feet broad, runs for a mile or two througli the Roman Camp field, where for a distance of about 70 feet on either side the shale has been rendered useless. It is obvious that the heat from the molten material has distilled the shale. There was no gas in the burned seam, Ijut the cracks and crevices of the igneous rock itself were charged with inflammable gas under considerable pressure. When the dyke was reached in the mine, it was covered by a thin compact layer, and after its removal there was a sudden discharge of brackish water, which contained 785 grains per gallon of total sohds, consisting of lime, magnesia, and alumina as carbonate and chloride, but with no sulphate. When the shale was suddenl}^ distilled by the igneous rock, there would be no escape for the sudden pressure of oil vapours but into the molten material itself, and the temperature would be high enough to convert them into permanent gas. When an intrusive sheet occupies the position of a productive oil-shale, the former often contains pockets or small hollow spaces partly filled with liquid or solid hydrocarbons — evidently the products of distillation. For example, at Albyn Mine, Broxburn, where a basalt sill about 5 feet thick takes the place of the Broxburn grey seam (9) for a considerable distance, these cavities, partly filled with viscous hydrocarbons, appear in the igneous rock. It is a yellowish-grey semi-solid mineral wax. When analysed by R. Tervet, London, it gave : carbon 84*35 per cent., hydrogen 12*83 per cent., nitrogen 1*68 per cent. — total 98*86 per cent. There were traces of sulphur. The cavities were lined with calcite. The wax darkened on exposure to air. Around some cavities barite was found. The temperature of the intruded matter could not have been very high, otherwise the hydrocarbons would probably have been converted into permanent gas. It is remarkable that the curly seam, lying only 8 feet below this sheet, is not in the least affected — another indication of moderate temperature. The Dunnet Mine proceeds from the Broxburn Oil Co.'s Albyn Crude Works in the direction of East Mains Steading, cutting through the strata at an angle. At 16 feet under the Dunnet it enters a dolerite sill of unknown thickness, for 10 feet. 'There are cavities in the sill with liquid petroleum and sometimes with semi-solid or solid bitumen. At 6 feet above the top of the sill there is a shale about 1 foot thick, which has been completely destroyed by the heat, and no doubt the hydrocarbons in the cavities are from its distillation. The Dunnet Distillation by Intrusive Sills. 169 Shale, 8 feet higher up, seems not affected but is of the usual quahty ; but it contains here and there specimens of albertite. The cavities are lined with calcium carbonate or calcium and magnesium carbonate. The liquid petroleum has 25 per cent, loss in refining, and in this agreed with crude oil from the retorts and differed from the petroleum got in the sedimentary strata of the Sandhole pit. The following is the analysis of the Dunnet Mine petroleum from the sill, and for com- parison the analysis of Broxburn Crude Shale Oil, and these may be compared with the analysis of Sandhole pit petroleum on p. 166 : — Naphtha, Burning Oil, Gas Oil, Lubricating Oil, Paraffi i Loss in Refining Sp. gr. •740 •810 •840 •865 •885 uunnet iretroieum. Sp. gr. •866, v.Tuae onaie uii Sp. gr. -868. S. pt. 65° F. S. pt. 83° F. 4'5 per cent. 3^5 per cent. 361 320 • • >» 4-0 6-6 6-0 190 18-0 8-8 110 M. pt. 106° F. M. pt. 115°F 26 "0 per cent. 100-0 25'5 per cent. 1000 The figures show a great similarity between the destructive dis- tillation underground, and the destructive distillation in the retorts. The bromine absorption in the burning oil of the Dunnet petroleum was, however, only 3'0 per cent, against 41^6 with shale burning oil. In 1884 the Hut bore was put down a little to the north of Albyn Works. At a depth of 496 feet the Dunnet Shale was passed through. Then came 10 feet of blaes. After that came 34 feet of what was repre- sented as "hard limey sandstone." This, no doubt, is the sill and its thickness in this bore. It was a steam-driven chisel bore, the only one tried by the company. When passing through this the rods came up coated with crude petroleum of semi-solid consistency ; sp.gr. •842 and setting pt. 75° F. (24° C). Hydrocarbons exist in meteorites. They seem, along with ammon- ium compounds, to exist in all volcanic gases. They are expelled by heat from granite and basalt. The lava of Etna contains soHd paraffins and Hquid oil in bubble-Uke pockets. Massive rocks far from active volcanoes contain hydrocarbons. Obsidians formed by the rapid cooling of lavas still retain water, ammonium chloride and bit- uminous or ammoniacal substances. The universality of the association of hydrocarbons with igneous rocks, and the vastness of the quantity when all are considered together, have caused several great authorities to conclude that these hydrocarbons are of cosmic or inorganic origin and not the products of life. (George F. Becker, U.S. Geol. Survey, Bulletin 401, 1909). At the present time plants or animals dying in air or in well aerated water, as in the most of the ocean, are resolved into gases or materials soluble in water, except hard materials such as shells : for the most part the soft organic parts disappear completely. But under special cir- cumstances where air is soon excluded, there are accumulations of organic matter, peat bogs for instance. Mud in many locahties has been found by different investigators to be charged with petroleum- or ozokerite-like bodies ; for instance, Stettin Gulf, near Ludwigshof ^ 170 Chemistry of the Oil-Shales. Saltmarsli at Bouche d'Erquay, Brittany, Portuguese East Africa, South Australia, &c. In tlie Mediterranean, between Cyprus and Syria, and also at Gulf of Suez, there is petroleum in the mud of the sea floor along with ammonia and iron sulphide. There is often a vast amount of Hfe in a mile depth of water, and in certain circumstances at present petroleum or kerogen is accumulating in considerable quantities. Potonie (loc. cit.) gives instances of this. Oxidised substances of a bituminous nature may be got from oxidation of hydrocarbons ; or, in other circumstances, as organic matter de-oxidised so far on the way to produce petroleum. Heavy hydrocarbons, liquid or soHd, may be direct productions from organic matter, or they may in other cases be built up from light hydrocarbon gases by polymerisation, or oxidation, or cumulative resolution, under pressure, &c. Refined mineral oils resist oxidation in the dark, but on exposure to light and air oxidation takes place through time. Spirit • 7 10 exposed to light and air gets heavier, and deposits a heavv, viscous, nearly colourless oil of sp. gr. 1-0425, containing acids. Burning oil exposed to hght and air through time deposits a brown tar, and this on fiu-ther free exposure becomes a brittle solid. The still grease that distils over near the end of a crude oil distillation becomes a brittle solid under the action of oxidising agents. These reactions correspond to some extent with the formation in nature of m neral pitch and asphalt from petroleum by evaporation and oxidation. Natural Gas in West Lothian Oil-Shale. Natural gas is plentiful in the Broxburn district. Twenty-five years ago water issued from many of the old bore holes charged with large quantities of gas, which was odourless, and combustible. In course of time, owing to the mineral workings, the water ceased to rise, and the bore holes were covered with soil, but the gas continued to reach the surface, reacted on it, and caused a smell like that of a choked sewage pipe, with sulphuretted hydrogen present. Thus long, narrow strips through the fields were rendered barren for some years. The waterlogged strata that had previously held down the gas had been drained dry by the workings, sometimes more than a mile away, and the gas escaped along the outcrop of certain porous rocks. From a bore hole at Middleton Lodge, about thirty years ago, there was a constant flow of water, and, regularly every month, gas was evolved with con- siderable force and noise, which, on hghting, burned for a day or two as a great column of flame seen from afar. At one natural vent at Broxburn the chemical reactions going on have caused the surface soil to have a temperature of 40° F. (22° C.) higher than that of the ordinary soil of the neighbourhood. There are two sources of the natural gas of this field — viz., the fire-damp given off by the coal and oil-shale, and the permanent gas created by the molten igneous rock when intruded into positions occupied by oil-shale. V. The Process of Manufacture. 1 . The crude oil works consist of benches of retorts, the condensers, and the ammonia house. They are generally placed in the middle of Processes of Manufacture. 171 the shale-field, and much of the shale is tipped from the miners' hutches into the breaking machine. As it is expensive to haul it far under- ground, pits or mines are sunk over the field, and the shale is brought in railway waggons to be emptied by hydraulic machinery into the breaking machine, but not from a greater distance generally than four miles. If shale lies several miles distant, a crude oil work is built and the crude oil is sent to the refinery by tank waggons. The shale is broken into small pieces by passing between two toothed drums, being too tough to break like road metal. From the breaker it falls into hutches (small waggons), which are taken up an incline by wire rope or chain to the top of the retort-bench, and emptied into the retorts. Development of Retorts. The first retorts tried by James Young were of the horizontal iron type, like those employed at the time in the manufacture of coal-gas. Coal is distilled in gas-making at a very high temperature with the object of making permanent gas, and as little liquid product as possible. Shale, on the other hand, is distilled at a low temperature to obtain liquid and solid products, and a small quantity of gas. Horizontal retorts (Fig. 68) were improved in shape, size, and build, Fig. 68. — Horizontal Retort. and were used in several of the smaller works till about 1880. They gave a large yield of burning oil as, for example, 27 gallons of crude oil were obtained from the Broxburn Shale, and the oil yielded 51 1 per cent, burning oil and naphtha, 5 per cent, of medium oil, 10 per cent, of lubricating oil, and only 5 per cent, of paraffin scale— total pro- ducts, 71^ per cent. Young soon discarded this form of retort, and adopted the vertical 172 Chemistry of the Oil-Shales. type (Fig. 09). It was a vertical tube about 10 feet long and a foot in diameter, with a hopper on top from which the shale could be dropped without escape of gas, and it ended below in a trough of water, through which the spent sliale was drawn every hour. New shale was dropjied from the hopper at hourly intervals, half an hour after the drawing, and the shale remained about eight hours in the heat. About 1860 steam was introduced into the bottom of the retort, which greatly improved the quantity and quality of the crude oil, as it diffused and moderated the heat and swept the products rapidly out of the high temperature. Old vertical retorts (Fig. 69), improved in form and lengthened, were used by some until 1880. Fig. 69.— Old Vertical Retort. Many forms of retort were tried, each introducing some new feature. One, which was highly successful and widely adopted for a time, was patented by N. M. Henderson in 1873. It was made of cast-iron, one and a half inches thick, fifteen feet long, of oval section two and a half feet by one foot. The charge was 18 cwt., which lay sixteen hours without movement in the retort, distilling off the crude oil, ammonia water, and permanent gas. Thereafter the spent shale, which contained about 12 per cent, of carbon, was dropped into the furnace below to act as fuel for the next charge. Four retorts were built into one oven and over one furnace, and one of the four was dropped every four hours to maintain the succession of heat. The permanent gas of the distillation was burned in the furnace or in the oven above, and steam superheated in this oven was introduced Modern Retorts. 173 into the retort. This type required much less fuel and at the same time made an easily refined crude oil, richer in heavy oil and solid paraffin than the crude oil of the older retorts. The old vertical type, fired by coal alone, was dependent on the attention of the fire- men, whereas Henderson' s retort gave the right temperature mechani- cally. The distillation was downwards. A little coal was generally used as extra fuel. The Young and Beilby retort (Fig. 70) was patented in 1881. Four metal retorts were connected with a large hopper above, common to the four. The distillation was upwards through the cold shale of the hopper, where the crude oil was condensed and redistilled. Each Fia. 70. — Young and Beilby Retort. retort had a metal upper part where the oil was distilled from the shale at a low temperature. After being practically spent of oil, the shale passed down through a lower part of the retort built of firebrick, where it was subjected to as high a temperature as possible without fusing, and was there acted on by steam. Thus the carbon was converted into a mixture of carbonic acid and carbonic oxide (the temperature was not high enough for perfect water gas), and the steam giving up its oxygen to the carbon yielded nascent hydrogen to combine with the nitrogen to form ammonia, and the excess of hydrogen went for fuel. The lower part is therefore a producer of ammonia and gas. The shale lay eighteen hours in the retort. This type greatly increased the permanent or fuel gas, and gave a larger yield of sulphate of ammonia. At intervals in the bench of retorts there was one for coal to act 174 Chemistry of the Oil-Shales. as a gas-producer to supplement the retort gas, and the ammonia from it was also saved. The retorts now in operation are framed on the Young and Beilby principle, two of which are described as examples. The Hetulerson Retort, No. 6726, 1889 (Fig. 71), in its newest form (Patent No. 26,647, 1901) has two toothed rollers at the bottom that support the weight of the column of shale, and, revolving at a regulated pace, Fig. 71. — Henderson Retort. keep the shale always in motion, which is discharged into a hopper below. There is a large hopper above to do away with charging by night. The products come ofT at the bottom of the top hopper. As regards aid from coal, Mr. Henderson adopted a separate gas-producer (the Wilson). Compared with previous types, the length of this retort was greatly increased, as the cheapest way of exposing the shale to a larger heating surface for a longer period, and thereby increasing the ammonia, while working at a temperature low enough to diminish wear and tear and ensure long life to the retort. In this Bryson Retort. 175 type the flattened form is adhered to, so that, even in the centre, the shale is never far from the heat, and thus any necessity for over- heating the outside is avoided. The present length adopted is 14 feet for the upper or iron part and 20 feet for the brick part. The section is oblong, 2 feet 9 inches by 1 foot 3 inches at the top of the metal part, and -4 feet 8 inches by 1 foot 10 inches at the bottom of the brick part. The total height from the ground-level to top of the hopper is 63 feet, and about 15 tons of shale are placed in it at a time. The shale remains in the heat of the retort for thirty hours. Fig. 72. — Bryson Retort. Thus the yield of oil was augmented by several gallons and the ammonia greatly increased, and the labour expenses much reduced. Each retort puts through over 4 tons per twenty-four hours, and enables the crude works to be made very compact. The retort patented by Messrs. Bryson, Jones, & Fraser, and generally called the Bryson Retort, Patent No. 7113, 1895 (Fig. 72), is also a very long one, and differs from that last described in having a circular cross-section. It has a table below to support the column of shale, and there is a revolving arm to maintain the movement of the shale downwards. The bottom hoppers converge so that a single line of rails under the centre of the bench receives the spent shale 176 Chemistry of the Oil-Shales. from both sides in a hutch. By these means labour is reduced to a minimum. The retorts described are all of the continuous-working variety, except Henderson's 1873, and the horizontal types, which were intermittent. The old vertical retorts gave a crude oil that was dark and tarry, sp. gr. '880 to -895. Henderson's 1873 pattern gave a green coloured crude oil sj). gr. -865 to '870, with 2 J per cent, more solid paraffin, a lubricating oil that was much more viscous, and 2^ per cent, more total products. The newer retorts give more crude oil per ton, which is not quite so easily refined and involves more loss in refining ; but the total refined products are more on the whole, and, what was not anticipated, the solid paraffin is increased. Long exposure to high heat tends to make paraffin break up into paraffin and olefine of smaller molecule. Olefines by deposit- ing carbon can become converted into paraffin Olefines at moder- ately high temperatures sometimes contract in volume and form condensation products containing paraffin. Retort Condensers. A main, common to a bench of many retorts, is led to the conden- sers from the retorts. On the way the vapours are chilled by passing through a tower in which water for the steam boilers is heated in pipes. The condensers are great stacks of vertical four-inch pipes, and the ammonia water and crude oil collected from them are run through a box called a separator, in which the water at once goes to the bottom and is run into one tank, while the oil rises to the sur- face and is run into another. The old vertical and Henderson retorts gave less than 3000 cubic feet of permanent gas per ton ; the new ones, of the Young and Beilby type, give about 10,000 cubic feet. This gas on leaving the condensers is scrubbed from ammonia and naphtha by passing up water towers, and finally up a heavy oil tower. The heavy oil showered down catches the light naphtha, which is afterwards distilled from it. The permanent gas, thus freed from all condensable matters, is caught by a fan which, giving a few inches of suction on the side next the condensers, forces the gas under a few inches pressure into the main that supplies the burners at the bottom of the retort flues. There is ^-inch suction on the retort- main that receives the retort exits. These modern types, with a good shale, require no help from coal in the distillation, except at the beginning. J. J. Coleman invented a method of extracting gasolene from the permanent gases by compression and cooling. The final cooling was made from 40° to 50° below zero F. (-40° to -45° C.) by expansion of the compressed cooled gases. Young's Company found that 1^ gallons were obtained at a cost of 2^d., while by the oil tower, three quarters of a gallon was got at a halfpenny per gallon. The oil obtained had sp. gr. -700 to '715. Coleman's method was soon given up. The brick part of the modern retorts is a gas-producer, in which the carbon is consumed by steam. Under 1000° F. the action of steam on carbon gives carbonic acid, COg, and hydrogen. At 1000° F. (538° C.) a little carbonic oxide, CO — a combustible gas — is formed. Higher temperatures increase the proportion of carbonic oxide. At 1800° F. Products of Distillation. YJI (782° C.) the. action is practically complete, only a small proportion of carbonic acid being formed. The shale in the brick part of the retort rises perhaps to 1300° F. (704° C.)- At that temperature steam acts on carbonic oxide CO, to form carbonic acid gas, CO.2, and hydrogen. Ammonia gas by itself begins to break up into its elements about 900° F. (482° C), and the decomposition is complete at 1400° F. (760° C). But protected by sufficient steam, the ammonia can exist at a much higher temperature. With great excess of steam, all the nitrogen goes into ammonia quantitatively. With the com- paratively small excess of steam that is practicable in a working retort, a proportion of the ammonia formed is decomposed into its elements, but the greater the excess of steam the smaller is the loss. The quality of the crude oil depends much on the temperature at which it is formed and to which it is afterwards exposed — a high temperature being injurious. An extreme case is using shale for gas-making. The shale of the Broxburn seam, when distilled in the gas works at a bright red heat, gave nine gallons of crude oil (or gas tar), sp. gr. -952, which was a thin mobile liquid containing little solid paraffin ; and sulphate of ammonia 8J lbs. per ton. This is the result of high temperature and absence of steam. Steam is a powerful reagent at the temperature of the retorts. Tervet in- creased the yield of ammonia by passing hydrogen into the retorts. Irvine increased the solid paraffin by introducing ammonia. This action of ammonia partly accovmts for the higher yield of paraffin in the recent type of retorts. Beilby found that a limited intro- duction of air increased the solid paraffin. Sulphur acts on paraffin at a high temperature to give sulphuretted hydrogen, H.^S, and ole- fine. Free sulphur is sometimes got in the condensers with the crude oil. Ammonia or a little oxygen in the retort unites with the sulphur and keeps it from attacking the hydrocarbon molecules. In the Henderson 1873 type, with its mild temperature and excess of steam, the shale of the Broxburn seam that contained 1-5 per cent, of sulphur dropped r4 of it into the furnace in the spent shale, and it contained 1 per cent, even when taken from the fu.rnace. 0-25 per cent, went to the permanent gas, 0-028 to the crude oil, and 0-02 to the ammonia water. In the present retorts much more sulphur is sent into the crude oil, water, and gas. Results of the Shale Distillation. The results of the shale distillation are : — Spent shale, that is of no value at present, while its removal involves expense ; permanent gas used as fuel for the retorts themselves ; cnide oil ; and ammonia water. Distillation of Ammonia Water. The ammonia water is now distilled in tower stills, the first used being that of Beilby (Fig. 73). There are others now in operation, of which the Henderson type is an example (Fig. 74). The ammonia water heated by interchange of heat with the spent ammonia water is run on at the top, and goes from tray to tray, acted on by steam of 30 lbs. pressure, blown in at the bottom of the 178 Chemistry of the Oil-Shales. column. Hence the water boils, and the volatile ammonia com- pounds are expelled as gas and caught in sulphuric acid. The sul- phuric acid used to refine the oil is separated from the tar by washing with hot water, and the recovered acid is saturated with the ammonia gas and sent into the market as sulphate of ammonia. This recovered acid gives a solution which has to be boiled down to obtain the salt, but the quantity got only serves for a fraction of the ammonia. The rest is passed into a cracker-box of fresh sulphuric acid, in lead pipes, with holes in the part laid along the bottom. There is a constant stream of sulphuric acid flomng in, and also a constant current of Fig. 73. — Beilby Ammonia Column StiU. ammonia gas. The sulphate forms as salt, and falls along a sloping bottom into a well, from which it is lifted by a steam injector and thrown into a box at the side to receive it. The acid requires to be diluted with water, and instead of fresh water the solution of sulphate made from the recovered acid is run in, and the separate evaporation of it saved. In the ammonia water from the retorts, there is fixed ammonia equal to 1 lb. per ton of shale, sometimes more if there is insuction of air anywhere, which is generally recovered by putting lime into the lower trays of the tower. In the water there are sulphur compounds, sulphide, sulphite, hyposulphite, and persulphides, and in the heat of the tower-still these react on each Crude Oil and Petroleum. 179 other to give free sulphur, which collects in masses and tends to choke the passages of the still. The milk of lime run into the tower helps to keep it clear. r\ n n 11 iLJUU wIAV Fig. 74. — Henderson Ammonia Column Still. Two Trays. Comparison of Crude Oil and Petroleum. The crude oil of petroleum is got without the expense of mining and retorting. A bore is put down and is tubed, and the oil flows like a fountain, or is brought to the surface by a pump. The gentle processes of nature used in creating petroleum, extending over long periods of time, give a crude oil much easier to refine than that pro- duced by the rapid and violent method of the shale retort, which yields unsaturated hydrocarbons and a little sulphur in some molecules. Crude petroleum in its first distillation separates a considerable proportion of burning oil which requires only one treatment each with oil of vitriol and with soda to render it fit for the market. Our burning oil requires three or four distillations, and hence the battle of com- petition is fought at a great disadvantage. A gigantic bench of 60 retorts, say, with 250 tons of shale put through per day, gives a very thin stream of crude oil and ammonia water. One compensation is the presence of ammonia ; another is, that the repeated distillations enable much more homogeneous products to be made. 'J'he great secret of oil-refining is thorough separation of one product from 180 Chemistry of the Oil- Shales. another. Naphtha renders burning oil dangerous, and intermediate oil hinders it from rising in the wick, and light oil or solid paraffin in lubricating oil reduces its viscosity. Petroleums vary in composition. That from Pennsylvania consists principally of the paraffin series, and the heavy oil at the end of a distillation contains solid paraffin. Ohio and Canadian petroleum consist largely of paraffins, but they have more sulphur compounds, which necessitate a special finishing treatment, or chemicals in the distillation ; but the sulphur compounds are easily struck out. Californian petroleum has a greater mixture of different series of hydrocarbons, and gives asphalt at the end of distillation instead of paraffin. The Californian petroleum, from the Tertiary strata, seems much nearer the original organic compounds in its nature than the Pennsylvanian petroleum from the Devonian rocks. Russian petroleiun comes from Tertiary rocks and is composed of naphthenes, a series of cyclic hydrocarbons. Some petroleums cause the plane of polarisation of light to rotate to the right, others to the left, which is almost conclusive proof that these petroleums, at any rate, are not of purely inorganic origin. The Refinery. 2. The refinery consists of (1) stills for the repeated distillation of the oil ; (2) stirring-tanks, in one set of which the oils are treated with strong sulphuric acid, and in another with caustic soda ; (3) paraffin-houses, in which the heavy oil containing the solid paraffin is cooled and pressed, and where there are great refrigerating machines ; (4) paraffin refinery ; (5) stock tanks for the finished product ; (6) filling shed with cooperage, where the products are filled into barrels and tanks to send to the customers ; and sometimes (7) a candle-house to make the solid paraffin into candles ; and occasionally (8) vitriol chambers to make the sulphuric acid required, and concentrating plant. Further, there are engineers' shops, smithies, carpenters' shops, saw-mills, plumbers' shops, clerks' offices, &c. &c. All have to be arranged for convenience, cheapness of communication, and safety from fire. The crude oil is settled from the ammonia water and shale-dust, and pumped up into a high charging tank, from which the oil can flow by gravitation into the stills. There are heat interchangers on the top of the stills, so that the cold oil-feed flowing in is heated by the vapours distilling out. There are high charging tanks behind each bench of stills and low tanks to receive the distillates. With every distillation, steam, more or less superheated, is introduced into the stills ; hence there are steam-boilers at hand. Water converted into steam expands about 1700 times. Our oils expand only one or two hundred times, and when distilled without steam a great deal of oil has to be evaporated before the vapours mount up to the exit pipe. Their specific heat and heat of vaporisation are not great, and they readily condense on the top of the still to fall back and be redistilled with some decom- position. When steam is introduced it cushions and protects the gaseous molecules from decomposition, and rapidly sweeps them into the condenser. Further, the presence of steam lowers the boiling point of the oil in much the same way as a vacuum or reduced pressure. Refining and Separation of Paraffin. 181 Refinery Operations. Distillations and Chemical Treatments. The crude oil distillation is meant to be a destructive one to some extent, and the steam admitted is limited. If the crude oil be treated directly with oil of vitriol and caustic soda the loss is very great. Or if too much steam is used in the distillation the loss with the treat- ments is great, as the steam drives the oil over unchanged. The distillation converts tarry or resinous matters capable of uniting with the chemicals into the required hydrocarbons. Steam is limited when near the end of the second distillation also ; but when the bulk of the heavy oil and paraffin is passing over the proportion of steam is high. The once-distilled oil is stirred up with oil of vitriol and the black viscous tar settled out. The oil is run by gravitation into another tank, where it is treated with caustic soda, and here another black viscous tar is separated. The settled oil is pumped up to the charging tank of the next distillation. The stirring with chemicals is sometimes done with mechanical stirrers, but oftener with ^ir, pumped into the bottom of the tanks (Fig. 81, p. 186.) At each distillation a fractionation is made, that is to say, the oil is separated into naphthas, burning oils, and heavy oils. In the crude distillation sometimes only the naphtha or spirit is separated and all the rest distilled together as " green oil." The burning oil is left with the heavy oil and paraffin so as to keep the mixture liquid at a comparatively low temperature for the acid treatment, otherwise a high temperature would be required, and this would cause the acid to attack the olefines. The amount of oil of vitriol used is limited for the same reason, as well as for economy. After the first treatment with oil of vitriol and soda, the next dis- tillation separates burning oils of various gravities and the heavy oil containing paraffin. The burning oils are distilled again, sometimes repeatedly. The oils vary in specific gravity in different works, and at different times in the same works, to suit the requirements of the market. Separation of the Solid Paraffin. The heavy oil is cooled in shallow tanks set in sheds open to the wind, and afterwards with freezing machines. The old cooling drums, dipping into the oil and paraffin and raising a film to be scraped off at the other side, are no longer used, as they chill the mixture too rapidly and prevent proper crystallising of the solid. Ammonia machines are now always used, some beginning with ammonia solution, and others with dry gas liquefied by pressure. The ammonia solution machines cool a solution of chloride of calcium which cannot be frozen by the machine, and this chilled brine is put into a tank filled with alternate compartments ; wider ones for the oil and paraffin and narrower ones for the brine. The oil and paraffin lie there for hours exposed to the cold, and the solid paraffin separates out in good crystals. In the Beilby cooler, the paraffin mass lies undisturbed until chilled to the extent required. In the Henderson cooler, a scraper goes slowly round, removing the chilled mass from the cold plate and letting 12 182 Chemistry of the Oil-Shales. the warmer material forward to the cold. Paraffin is a bad conductor of heat, and, in the Beilby cooler, the paraffin mixture requires to lie a long time and necessitates a large plant, but gives a better crystal. In the Henderson cooler much more can be put through and yet a sufficiently good crystal is obtained. Some works utilise the cold more by passing the paraffin mixture through pipes, chilled directly by the evaporating ammonia gas, which produces more sudden chilling, and causes some paraffin to thicken in an amorphous state difficult to separate from the oil. From the cooling machines the paraffin mass, after being broken up by machinery, is pumped through filter Fig. 75.— Henderson's Sweating Trays. Cross vertical section of a sweating house on the tray system. D are the trays, lying on horizontal pipes C, which are supported by vertical pipes at the side. A are the steam pipes for heating. presses. The paraffin cake collects in the press and the oil flows into its own tank. When the cooling is done by the ammonia gas without the interposition of the brine, many more filter presses are required on account of the amorphous paraffin. The paraffin from the filter presses is generally further squeezed in cloths in hydraulic plate presses. At this stage it is called " paraffin scale," from the scale-like appearance of the flattened plastic crystals. The heavy oil separated from the solid paraffin is called " blue oil," which is treated with oil of vitriol and soda, and is distilled again and separated into the various fractions according to gravity required. These, after cooling and pressing from soft paraffin, and when further Extraction of Paraffin. 183 treated with oil of vitriol and carbonate of soda, are ready for the market. If the solid paraffin is thoroughly separated from the lubricating oil, the latter becomes proportionately heavier in gravity and more viscous, and the setting point is lowered. The solid paraffins are refined by a sweating process. In some works the cakes of paraffin scale from the filter presses are not squeezed in hydraulic plate presses to separate the oil, as this process requires much hand labour, and the paraffin, with a proportion of oil, passes directly from the filter presses to the paraffin refinery. The paraffin is melted, cooled into cakes, and put on wire-gauze shelves in a house kept warm by steam pipes. As the temperature rises the oil sweats out and also the softer paraffin, leaving the hard paraffin on the shelf freed from colouring matter. The process is repeated to improve the colour. N. M. Henderson has a sweating apparatus that reduces the labour Ei=i -iii — Uf- a ■^ A ;SSJ=r.- 1 -==S1 Fig. 76. — Vertical Section of Henderson's Cell-Sweating House. to a minimum, and has been adopted all over the world. The house containing the apparatus is filled with great trays several inches deep, in whicii wire-gauze shelves are placed two inches from the bottom. Water flows into each tray up to the shelf, and two inches of melted paraffin are run on the top of the water. The doors are open, and the wind cools and solidifies the paraffin . Artificial wind is created to help the cooling. When the paraffin is solid, the water is run off below, which leaves the great cake of paraffin lying on the wire-gauze shelf. The doors are shut, spent steam from pumps and engines is turned into the heating pipes, and the paraffin is gradually sweated. The sweatings are run into receivers according to melting point and colour. When finished, the wax is melted out by putting steam into the pipes, which are used as supports for the trays, and the refined wax is run into its own tank (Fig. 75). Mr. Henderson has patented another method of sweating which has certain advantages over the tray method (Figs. 7(3-78). There are vertical cylinders 9 feet high, and 17 inches diameter, with a central 184 Chemistry of the Oil-Shales. cylinder? inches diameter, open at top and bottom inside the other one. The space for the paraffin is between these cyhnders, and this space has a bottom with exit-pipe, and a false bottom a few inches above it, up to which water is filled before charging the paraffin. Three plies of wire gauze are laid around the central tube in the paraffin space. There =13 Fig. 77. — Plan of Henderson's Cell-Sweating Hon.=e. is thus on cooling, a paraffin cylinder of 5 inches radial thickness cast around the central tube. The paraffin crystallises first at the outside, throwing the oil and soft paraffin towards the gauze. After solidification and running off the water below, the chamber containing these cells is shut and gradually heated up as in the tray stove, and the Figs. 76, 77, and 78 represent Henderson's Cell- sweating arrangement. Fig. 7G shows a house in vertical section. It contains 72 cylindrical cells (A), of which four are shown. B is the charging pipe. C is the run-off pipe, first for the sweatings and after- wards for the wax. D is the steam pipe for heating. Fig. 77 is the house in plan, showing twelve of the cells in section. B is the charging pipe, C C run-off pipes, and D steam pipes for heating, imder the cells. Fig. 78 (a) is a vertical section of the lower part of a cell : and (h) a'] plan of the same; A being the central tube open' to the air above and below, B the wire gauze to keep a road for the drainings to escape, C the space for the paraffin, D the false bottom, and E the exit. Fig. 78. — Plan and Section of a Cell. sweatings always have free passage among the gauze. Rows of cells vent into one pipe below, in which a slight vacuum is kept up by a steam injector near the pipe exit. The cells of thin sheet-iron are much cheaper to erect and repair than trays ; nearly double the quantity of paraffin can be sweated in the same space and time, and The Oil-Stills. 185 the fractionation is much more perfect, giving a larger yield of refined wax {Jour. Soc. Chem. Indust., xxx. p. 269). Some paraffin is refined by mixing with about 30 per cent, of naphtha ; it is then cooled in cakes and pressed, the naphtha flowing out and carrying the colouring matters. The cakes of paraffin are melted, and the naphtha is distilled ofE and condensed. The paraffin is thoroughly steamed till the smell of naphtha disappears. In all cases the melted paraffin is stirred with animal charcoal, settled, and filtered through paper. It is then ready for the candle- house or the market. The Stills. In the distillations the bulk of the oil is distilled off from boiler-stills, which are ^f rizontal cylinders, the charge being two or three thousand gallons, and the residue is run into round cast-iron-bottomed stills (Fig. 82, 4) to be distilled to dryness and coked. The still coke of the crude oil is valuable. When the coking is in progress, much perma- nent gas is given off, very pure, of high luminosity, and valuable for lighting or fuel (Beilby and M'Arthur). These gases used to be passed into the atmosphere and lost ; now they are all carefully utilised after scrubbing light spirit from them. Henderson's method is shown in Figs. 79 and 80. At the exit from the worm-tank condenser there is a U-tube seal pipe of sufficient depth to withstand the vacuum used. Between this seal and the tank rises a pipe with two-way cock, by which there is communication with a vertical pipe venting into the atmosphere when the still is not working, or with a pipe for drawing off the gases when the still is working. The latter gas-pipe is water- sealed in a hydrauhc main, by which the gases pass to a vacuum pump {Jour. Soc. Chem. Indust. xxx. p. 268). (See Figs. 79 and 80.) Fig. 79. — Henderson'.s System of Re- covery of Still Gases. Fig. 80. — Henderson'sSystem of Recovery of Still Gases — another view. Figs. 79 "and 80 illustrate Henderson's method of utilising the permanent gases evolved in the distillation of the oils. A is the worm-tank condenser, B the exit of the distillate to the receiver with a U-tube to prevent the gases escap- ing along with the oil. The gases are taken upwards through a two-way cock, which sends them, when necessary, by the pipe D into the atmosphere, but in general to the vacuum pump through the pipe E, which lutes into water in main F. 186 Chemistry of the Oil-Shales. N. M. Henderson connects boiler-stills into a series (Fig. 82), the oil flowing from one to another, and each giving ofi a distillate of a fixed specific gravity. They are worked continuously, save when temporarily stopped for cleaning operations. At the end of the series is a residue still with cast-iron bottom, which, when charged, is disconnected and another residue still is put on to the series. By this method twice as much oil is put through as when the stills are separate, and the distillation is more perfect and requires less oversight. In a crude oil distillation by the old method, naphtha passed over first, and was run into its own tank. At a certain specific gravity the distillate was run into another tank. The temperature in the still gradu- ally rose, together with the sp. gr.* of the distillate, the latter giving in succession burning oil, interme- diate oil, heavy oil with parafiin, and at the end still grease. The specific gravity had to be constantly tested to fix when the materials should be turned into another tank. With the connected stills, the first always discharges naphtha, the second burning oil, the third intermediate oil, and the fourth heavy oil and paraffin. There is considerable power of adjustment to suit what is required. In the manipulation with oil of vitriol, the tar from the finishing treatment is used to give a first treatment to the crude oil distillate. The tar from this oil is washed with hot water to separate the sulphuric acid, which is sent to the ammonia house, and the tar, neutralised with soda tar, is settled and burned as liquid fuel under the stills, Fig. 81. — Acid or Soda Washer, stirred with air. Fig. 82.— Connected Boiler Stills (1, 2, 3) with Residue Still (4). being blown into .spray with superheated steam. It burns like a jet of gas, with smokeless flame, and the chimney gases have no more sulphur than from coal. Quantities of Chemicals used. — To the crude oil distillate is given acid, equivalent to more than 2 per cent, of oil of vitriol, the after treatments of the light oil ^ per cent., and the finishing treatment of burning oil 1 to 2 per cent., according to previous treatment, &c. Distillation of Crude Oil. 187 The blue oil receives about 1 per cent, of oil of vitriol and a finishing treatment after fractionation from 2 to about 4 per cent, oil of vitriol. The caustic soda treatments are about 1 per cent, of solution of 60^ Tw., or 1"3 sp. gr., except in the finishing treatment, when the burning oils receive very weak caustic soda, and the lubricating oils carbonate of soda solution. To the blue oil is given dry caustic soda in the still, from 2 to 5 lbs. to 100 gallons. The form of still is shown in Fig. 83. Fig. 83.— Heavy Oil Still. The following is a scheme of refinery operations. O.V. means Oil of Vitriol, and C.S. Caustic Soda : — [Table 188 Chemistry of the Oil-Shales. 02 CO o o oi Ph > O >T3 d o . -^il- ea =*^ So 20 $ i oft- 'S •O — a o TJ o o U ^1 d <* iiS — SI. cS-iJ d _o. o =1 s Si *2 -co eao 05O = d£ Ot: o -o cS — «>! dl Products of Manufacture. 189 The crude oil obtained from shale is substantially a mixture of the paraffin and olefine series, with a small admixture of naphthenes and benzenes, which constitute the finished products. Both the paraffin and olefine series occur in the naphthas and burning oils ; but when we come to the heavy products there is a separation, for the solid paraffin consists of members of the paraffin series alone and the lubricating oil separated from it, of olefines with admixture of liquid paraffins. In addition to these products, the crude oil contains the materials of the tars separated by the chemicals, in which there are no doubt many compounds not yet determined, for their in- vestigation is both difficult and disagreeable, and some of them decompose very easily. There are phenols, cresols, and hydrocarbons with less hydrogen than olefines ; there are pyrene and chrysene ; there are also the quinoline and pyridine series of bases. These last are difficult to decompose, and can be got by themselves for separation from each other and examination. The leucoline (quinoline) series was investigated by Robinson and Goodwin [Trans. Roy. Sac. Edin., Vol. XXVIII., p. 561 ; Vol. XXIX., pp. 2(55, 273), and the pyridine series by Garrett and Smythe [Trans. Choii. Soc, 1902, 1903). Shale- oil naphtha contains one-half per cent, of pyridine bases. Dr. Thomas Gray investigated the phenols of naphtha soda tar [Jour. Soc. Chem. Iniustry, XXL, p. 815). The members of the olefine series have a higher specific gravity than those of the paraffin series, and the series with still less hydrogen than the olefines possess an even higher specific gravity. These last are struck out by the oil of vitriol, which reduces the specific gravity of the oil left. The more unsaturated hydrocarbons and the sulphur compounds have an odour like garlic. A small trace of these gives the penetrating smell to paraffin oil, and its removal, without destroy- ing any of the right products, is the problem of the refiner. The oil of vitriol used in refining combines with the pyridine bases and other basic substances, the bulk of the phenols, the sulphur compounds, and the hydrocarbons that are less saturated than olefines. The caustic soda solution extracts phenols and acids. If the olefines are not attacked by excess of oil of vitriol, the caustic soda tar is black. In the finishing treatments an effort is made to extract the last traces of the compounds more unsaturated than olefines, and also the sulphur compounds, and for this purpose sufficient acid is given to attack a little of the olefines. Hence compounds are formed which give a white emulsion with soda solution. Any trace of the soda sulpho-compound left in the burning oil causes crust in the wick of the lamp, and care has to be taken to wash it all out. vi. Products of the Manufacture. The products of manufacture will be discussed under two heads : (1) their composition and properties, and (2) their uses. 1. THE COMPOSITION AND PROPERTIES OF THE PRODUCTS OF MANUFACTURE. 1. The Permanent Gases of the Retorts. — These are used for fuel. The composition varies with the state of the retort at the time and 190 Chemistry of the Oil- Shales. with other circumstances. Excess of nitrogen indicates that air has been sucked in bv the action of the exhauster. 1 1 Young & Beilby Ketort. Herinand Tyi^e. (Prof. W. Foster.) Henderson's 1873 Retort. Henderson's New Retort, 1901. Bryson Ketort. (Bryson.) Carbonic Acid aud HgS Olefines Oxygen Carbonic Oxide, C . Marsh-gas . Hydrogen . Nitrogen 20-7 1-G 3-6 1-16 8-66 21-68 42-6 18-0 5-0 2-0 0-0 38-4 28-7 7-9 26-0 1-2 ro 7-8 9-2 38-6 16-2 22-08 1-38 1-18 9-77 3 70 55-56 6-33 100-0 100-0 100-0 100-00 2. Shale Naphthas are thin, limpid, mobile, colourless liquids, completely volatile at ordinary temperatures. They generally consist of 60 to 70 per cent, of olefines and other hydrocarbons acted on by fuming nitric or sulphuric acid ; the rest being principally of the paraffin series. Broxburn Naphtha, sp. gr. -735, was subjected to many fractional distillations in the Le Bel Henninger apparatus of 6 bulbs. The olefines, &c., were separated with concentrated sulphuric acid, and what remained was washed with water and soda solution. The results were as follows : — Range of Volumes. Loss by Treatment. Parafifius. 01e6nes, &c. 1. Temperature. Volumes. Per Cent. 26 to 37°C. . 4,000 2,800 30 70 2. 37 ,, 45,, 5,000 3,200 36 64 3. 45 „ 58,, 2,275 1,225 46 54 4. 58 „ 65 „ 9,300 5,125 45 55 5. 65 ,, 67,, 4,900 2,600 47 53 6. 67 „ 69,, 14,200 7,200 50 50 7. 69 „ 72„ 10,110 5,160 49 51 Tn the oil from the Henderson 1873 retort, there was often no benzene, but in the oil from the existing retorts the benzene series is distinctly represented. In Broxburn Naphtha, sp. gr. -735, the fractions boihng between 55° and 75° C. gave 2-6 per cent, benzene, and the fraction 100° to 105° C. gave 2-5 per cent, toluene. The members of this series were found to distil at temperatures under their boiling points when distilled pure ; and, where they were ex- pected, fractions sometimes showed no trace of them. The naph- thenes methyl-tetramethylene, pentamethylene. and hexamethylene were got in distinct quantities. (B. Steuart, Jour. Soc. Chem. Ind. XIX., p. 986.) Friedrich Heusler has examined the fraction of Scottish paraffin oil boiling below 110° C. (naphtha or spirit), and found paraffins 42 per cent. ; naphthenes 10 per cent. ; aromatic hydrocarbons Products of Manufacture. 191 7-3 per cent. ; olefiues 39 per cent. He proved the presence of benzene, toluene, metaxylene, and cumene, and the absence of naphthalene. The corresponding figures he obtained for Saxon lignite — of vegetable origin — were : — paraffins 16, naphthenes 4, aromatic hydrocarbons 45, and olefiues 31 per cent. 3. The burning or lamp oils are transparent, nearly colourless, thin liquids, having both the paraffin and olefine series in large pro- portion. There are 30 to 40 per cent, of unsaturated hydrocarbons that can be taken out with fuming sulphuric acid. 4. The lubricating oils are transparent, yellow-coloured, bright liquids with considerable viscosity. For oils from the same source, the viscosity varies with the specific gravity ; but for oils from different sources the specific gravity is no gauge for the viscosity, as the lower gravity of oil may have the higher viscosity. They are to a large extent olefines, but mixed with liquid paraffins. 5. The solid paraffins are colourless, tasteless, odourless bodies, composed of saturated hydrocarbons. They are able to resist the action of the strongest chemicals, which makes them useful for many purposes. They are good insulators. They are somewhat plastic for a good many degrees below their melting points, and hence low melting point candles sometimes bend with their own weight in hot weather. The flashing point of wax of M. pt. 128° F. (53° C.) is 375° F. (190° C). Heated in a bath in air the vapours do not ignite spontaneously at 620° F. (327° C). The solid hydrocarbon we now call paraffin was extracted from Tegernsee petroleum by Fuchs in 1809. Buchner separated it in comparative purity in 1819. Reichenbach, in 1830, obtained it from wood tar, investigated its properties, and called it by its present name. About the same time Sir Robert Christison of Edinburgh extracted it from Rangoon petroleum. Laurent got it from bituminous shale in 1830, and Dumas in 1835 from coal-tar. Selligue, in France, seems to have been the first to manufacture it for sale ; and Rees Reece made paraffin candles, in 1850, from paraffin obtained from Irish peat. Young obtained some paraffin from his Alfreton petroleum in 1848, and he was the first to manufacture paraffin in large quantity — viz., in connection with the Scottish paraffin oil industry. The following table gives the properties of average samples of the usual products : — Flash Point Tint. No. 500 glass Boiling Point Viscosity by a certain Pipette. Sp. Gr. Range. Lovibond. 2-inch Cell. Range. Motor Spirit Spirit or Naphtha .... •715 ^ •735 V •740J Lowest temperatures. Colourless. 120°F.-300°F. 140 „ 320 „ ISO „ 380 „ Special Oil, or Water-white Oil •785 100^.-120°^ 310 „ 500 „ Crystal Oil •800 115 „ 125 „ 6-5 340 „ 575 „ No. 1 Burning Oil . ■805 110 „ 135 „ 0-75 310,, 580,, Lighthouse Oil .... •810 145 „ 160 „ l^n 390 „ 573 „ Mineral or Marine Spenn •830 200 ,, 230 „ 2^0 450 „ 075 ,, Mineral Colza •840 220 „ '240 „ 5 500 „ 700 „ Gas Oil •855 200,, 230,, 450 „ 710 „ Gas Oil, Grease Oil, Cleaning Oil . •870 275,, 300,, 500,, 720,, Lubricating Oil ... . •865 275 „ 300 „ 1.5" 575 „ 710 „ 44 seconds. " ■ • • • j -875 300 „ 310 „ 18 J -inch Cell. 575 „ 800 „ 47 J» 1» • • • • •8-5 320 „ 340 „ 15 650 „ 870 „ 55 •890 330,, 350 „ 16 720 „ 875 „ 70 192 Chemistry of the Oil-Shales. In determining the flashing point tlie Abel apparatus is used ; the whole apparatus for the lower flaohing burning oils, and the cup of it for heavy oils. The tint is taken by diflterent methods. The method of taking the boiling range most recognised is that of Engler. The viscosity or body is generally taken with a pipette, each company having its own standard tube. There are viscosimeters by Redwood and by Engler that are used as standards of reference. The boiUng range of oils, taken with a new Baly & Chorley high temperatm-e sodium-potassium thermometer (1893), is set forth in the annexed table — Lub. Oil. Lub. Oil. Lub. Oil. Oil. Oil. 890/5 885/90 865 840 1 830 Temp. Sp. Gr. Temp. Sp. Gr. Temp. Sp. Or. Temp. Sp. Or. Temp. Sp. Gr. First drop over . 725-F. 675°F. 575'F. 450°F. 5(I0°F. 1st 10 per cent, over 745 „ •886 705 „ •878 600 „ •856 500 „ •806 1 610 „ •818 2nd 10 745 ,, •888 715 „ •880 605 „ •857 530 „ •823 515 „ •821 3rd 10 750 ,, •889 720 „ •882 610 „ •858 545 „ •829 5-20 „ ■824 4th 10 „ „ 700 ,, •891 730 „ •884 615 „ •860 .560 „ •836 530 „ •826 5th 10 770 „ •895 740 „ •887 620 „ •861 570 ,, •839 540 „ •829 6th 10 780 „ •S98 755 „ •890 630 „ •863 .585 „ •843 550 „ •830 7th 10 790 „ ■901 775 ,, •893 635 „ •864 605 „ •847 565 „ •831 8th 10 803 „ •904 795 „ •898 650 „ •80S 630 ,, •852 585 „ •832 9th 10 820 „ •907 830 „ •904 670 „ •872 660 ,, •656 615 „ •834 (95 „ „ ) 830 „ 840 „ 680 „ 675 „ 630 „ (97-5 „ „ ) 850 „ 850 „ 695 „ 690 ,, 645 „ 10th 10 875 „ •'mi 880 „ •912 710 „ •879 : 700 „ •803 675 „ •841 10,000 fluid grains were distilled from a copper flask, and the distillate was collected in 10 per cent, fractions and the sp. gr. of each fraction taken. 2. THE USES OF THE PRODUCTS OF MANUFACTURE. Naphtha or spirit, completely volatile at ordinary temperatures, is got at different specific gravities and boiling points according to requirements — "660 for gasolene, for instance, and "700 to '720 for motor spirit. Ordinary naphthas, '725 to "745, are largely used for lighting purposes in special lamps in workshops, shipbuilding yards, &c. ; and, for solvent purposes, in dissolving india-rubber, for water-proofing, &c., and removing grease from clothes, &c. ; for dissolving gums and resins, wool-washing, paint-mixing, in the pre- paration of varnishes and of alkaloids, extraction of oils and fats, in linoleum making, and largely also for the refining of paraffin wax. It has been employed for freezing machines, and also as a local anaesthetic. Burning oils are used for lamps of many forms, sp. gr. varying from -785 to -830, and flashing point from 105° F. (40° C.) to 230° F. (110° C). Scottish oils have been free from lamp-accident fatalities since thei^ manufacture over sixty years ago. The special, or water- white oil (sp. gr. '785), is serviceable for continuous burning lamps for buoys, lightships, &c., which can be retrimmed only at long intervals, from a week to a month. These burning oils are also utilised for combustion in oil engines. Lighthouse oil is specially safe for light- houses. Marine sperm is employed on board ships, with lamps slightly modified to suit the heavier oil, and it does not give off vapour that can ignite until much above the boiling point of water. Mineral colza (sp. gr. "840) is used also with special lamps. Use of Products of Manufacture. 193 Intermediate oils (sp. gr. -840 to "870) are used for gas-making. They are very pure, require no refining for the gas, and are employed where gas-lime is objectionable. They produce gas of high illuminat- ing power, and they are largely used for enriching coal or water gas. Oil-gas, compressed, is used for lighting railway carriages. Safe itself under pressure, it has also the power of rendering acetylene safe. Acetylene is very rich in light-giving power, but is by itself explosive, so that it may not be stored under greater pressure than 3"6 lbs. per square inch. If one part of acetylene be mixed with four parts of oil-gas, the Home Office Regulations allow pressures up to 150 lbs. p:}r square inch. Intermediate oils are employed for combustion in oil engines. Large quantities are now used as fuel by the Royal Navy. Mineral oils of all kinds, but chiefly the intermediate oils, are used for cleaning purposes, for removing rust from iron, and gummy matter which collects on machinery bearings when vegetable or animal oils are used as lubricants, &c. Intermediate oils are also employed for grease m.aking. In the tropics heavy mineral oils are effective for protecting wood work from the white ants (termites.) Lubricating oils are made with sp. gr. varying from 'SGo to "OlO, and are used either alone or mixed with vegetable or animal oil. Mineral oil prevents vegetable or animal oil from undergoing spon- taneous combustion on cotton waste, &c., and thus greatly increases the safety of these fatty oils for ,employment in mills (Galletly). Shale lubricating oils do not decrease so rapidly in viscosity by heating as some other mineral lubricating oils. Vegetable or animal oils, by the action of steam at high temperatures, produce free fatty acids, which corrode cylinders and the boilers, when, for instance, they are returned to the boilers of marine engines from the condensers. Mineral lubricating oils are quite neutral and safe under the same circum- stances. Some companies, therefore, produce cylinder oils. The solid paraffin is used in vast quantities for candle making. The usual grades are— melting point 130°, 125-127°, 118-120°, and 110-112° F. (54°, 52-53°, 48-49°, 43-44° C). The sticks of matches are dipped into the softer paraffin, M. pt. 100° F. (38° C), as a phos- phorus flame does not readily kindle wood, and dipping the end of the match-stick in melted paraffin helps the kindling in place of the old sulphur method. Soft paraffin is largely employed for miners' lamps, hand-lamps, lamps for household purposes, and ship lamps, owing to its safety, the flash point being 355° F. (180° C). Paraffin is used also for vestas, tapers, and night lights. Paraffin is used for waterproofing cloth, boots, walls, cartridges ; for coating the insides of barrels, vats, and other vessels, to prevent the wood giving a taste to the delicate substances in the vessels, such as butter, mineral waters, beer, cider, &c. A thin coating is service- able for protecting metal articles or machinery from rust or decay. It is employed for insulating purposes in electricity, as splints in surgery, for making thin sections for the microscope, as a medium for salves, for extracting perfume from flowers, supplying material for bees to make into comb, for waxing thread, floors, &c., and for many other purposes. Still grease is the amorphous distillate from the end of the crude oil or heavy oil distillations, and is employed for grease making. 194 Chemistry of the Oil-Shales. Still coke, which is the residue left in the still on distilling crude oil to dryness, is an important product. It is serviceable for gas fires in private houses, and is a favourite fuel in drawing-rooms. It is employed as a smokeless fuel for yachts, as carbon for electrical purposes, and for making moulders' blacking. &c. Sulphate of ammonia is a manure extensively used by agriculturists at home and abroad, and is particularly in demand for growing sugar beet. A solution may be employed for the prevention or extinction of fire. Liquid fuel. — At present the tars extracted with chemicals are used as liquid fuel for the stills, together with dregs and residues not fit for any other purpose. Our ordinary products are too valuable to be used for fuel. Crude petroleum and petroleum residues are now largely in demand throughout the world for firing steamships and railway trains, and our own oils might partly be used for tliat purpose in time of war. Only the cheapest Intermediate Oils are at present used by the Admiralty. The thermal value of oil-fuel is in general more than one and a half times that of coal, and it can be burned without producing smoke, can be stowed more compactly, easily, and rapidly, and requires fewer firemen in the stoke-hole. The following publications may be consulted for a general descrip- tion of oil- works : — Iltyd J. Redwood : Mineral Oils and their By- products. Sir Boverton Redwood : Petroleum, 2nd Edit., Vol. I., p. 418. Mills : Destructive Distillation (with a Bibliography at the end). Brunton : Proc. Inst. C.E., 1881. Steuart : The Gas Institute Trans., 1887 ; and Jour, of Soc. of Chem. Industry, 1889, p. 100. Articles in Ure's Dictionary and Muspratt's Chemistry, Thorpe's Dictionary of Applied Chemistry, &c. For special branche;; : — Beilby : Jour, of Soc. of Arts, 1885 ; and the following communications in The Jour, of Soc. of Chem. Industry : —Nitrogen and Ammonia: Beilby, 1884, p. 216; 1891, p. 120; Tervet, 1883, p. 445. Retorts : Rowan, 1891, p. 436 ; Beilby, 1897, p. 876 ; Henderson, 1897, p. 984 ; Crichton, p. 988 ; Bryson,p. 990 ; Irvine, 1894, p. 1038 ; Tervet, 1895, p. 1028. Gas : Beilbv, 1887, p. 212. Paraffin : Beilby, 1885, p. 321 ; Tervet, 1887, p. 355"! INDEX. Abbeyhill Shales, 4, 27, 42. Abden Fish-Bed, 87. Accidents in blasting, 107. Addiewell, 26. Admiralty Fuel Oil, 193, 194. Airdrie Shale, 141, 146. Albertite, 159. Alderston, 29. ■ Bellsquarrv and Newpark Dis- trict, 28-30. " Alfreton coal-pit, 136. Almond,pre-glacial channel of River,76. Almondell, Pumpherston Shales near, 45. Ammonia water, distillation of, 177. Analyses of crude oil from the different seams, 155, 156, 157. Scottish shales, 154. Arch, Dechmont, 12, 31, 60. • Kirkliston, 12, 77. — Pumpherston, 12, 53, 60, 67. Pentland, 13, 80. Arthur's Seat lavas and volcanic rocks, 3. Ash, Barracks, 8, 13, 18, 30, 31, 41, 47, 50, 62, 71, 74. Cross wood, 17. Port Edgar, 61, 62, 69, 73, 74. St. David's, 83. Shale, 159. _^_ Two-foot, 13, 59, 64. Auchengray, shales near, 19. Australian Shales, analyses and works results, 162, 163. Barnton railway cutting, contact phenomena in, 15. Barracks Ash, 8, 13, 18, 30, 31, 41, 47, 50, 62, 71, 74. Limestone, 8, 18, 30, 31, 33, 36, 37, 41, 47, 50, 62, and footnote. Beilby ammonia column still, 177, 178. retort, 173, 174. Bell, Robert, 142. Bellsquarry, 29. Binny ozokerite, 142, 14.3. Sandstone, 9, 18, 21, 24, 32, 37, 48, 50, 55, 58, 62, 71, 75, 82. Bitumen, 159. Blackband ironstone, 52. Blaokbrao Fault, 26, 27. Blackburn House, 31. Blackmire railway cutting, section in, 24. " Blaes," 7. Blasting and explosives, 105. Boghead gas coal, 137. • Mineral, 142. (See Torbanehill Mineral. ) Bore missing shale, 95, 96. Boring, cost of, 96. • methods of, 96. — ■ — percussive, 96. Brattice boards and cloth, section, 123, 124. Breccia, desiccation, 3, 90. explosion, 74. Breich Shale-field, 31, 32. Brick arching, 119. walling, 119. Brotherton Fault, 20. Broxburn District, 48-52. Marls, 9, 18, 22. 23, 32, 41, 48, 50, 56, 64. Broxburn Shales, 18, 22, 25, 32, 33, 37, 41, 48, 50, 55, 58, 75, 85. sections of, at Dalmeny, 76. ■ — — — ■ . Mid - Calder and Broxburn, 41. sections of, at Philpstoun and Champfleurie, 63. ■ (See Shales.) Burdiehouse and Straiton Shale- fields, 84-87. Limestone, 8, 17-18, 21, 24, 28-29, 35-36, 39, 40, 46, 54, 57-58, 61, 69, 72, 75, 78, 80, 83, 85, 88. Burning or lamp oils, 139, 186, 189, 191, 192. Burntisland, sections near, 80, 81. Shale-iield, 80-82. Cadeli,, H. M., 1, 2, 6, 41, 50, 54, 63, 69, 71. Calciferous Sandstone Series, 3. Calder Fault, 11,42. Camps Shale, 8. 21, 24, 36, 39, 41, 47, 49, 54, 58, 69, 73, 74, 75, 77, 78, 83. Carboniferous Limestone Series, 3. Carlops District, 87-88. Carlowrie, bores at, 75. Carriage inclines, 131. Cartridges. 105. Cements, Quccnsferry. 66, 67, 69, 70, 72, 77. Index. Cementstone Group, 3, 4, 42. Champfleurie and Philpstoun Shale- fields. 60-65. Shale, 5U. 55, 58, 63, 76. Charging and firing explosives, 106. Chemical composition of chief shales, 154-159. — of crude oil and ammonia, 143-158. CUapperton Hall Trough, 48. Burdiehouse Limestone at,46. Cleaning shot-holes, 105. Coai, Cobbinshaw Main Limestone and, 19-20, 26, 27, 33, 52, 65. Houston. 9-10, 19, 23, 26, 32, 33, 37, 42, 51, 56, 59, 64, 77, 82, 86. Coalheugh Head, Shale at, 27-28. Coal-measures, 3. Coal, Parrot. Westfield, Fife, 142. Two-foot, 19, 23, 26, 31, 37, 51, 59, 64, 142. Cobbinshaw Field, 16-20. Main Limestone and Coal, 19-20, 26, 27, 33, 52, 65. Cobbinshaw, South. Shale, 142. Column still, Bcilhy ammonia, 177, 178. ■ Henderson's ammonia, 177, 179. Comparison of crude oil and petroleum, 179. Competition, America and Russia, 137. Composition of products of manu- facture, 189. Constituents of crude oil, 189. Comstone at Selms, 42. Corston Hill lavas and volcanic rocks, 4, 17, 27, 29, 42. Corstorphine, 6. Cousie Braes, 129. Cousland and Seafield Shale-fields, 32-33. Craigleith Sandstone, 6. Craigs diamond bore, 47. "Creep," 110, 111. in coal or shale, 1 10. trouble with, 110. flection of strata in highly- inclined mines, 110. Crofthead, Burdiehouse Limestone near, 39. Crosswood volcanic asli, 17. C!rude oil and ammonia of f^halc as determined in the laboratoiy, 143. — works, 170. Crum Brow^, Prof., 143. Cuddie Braes, 129. Cut chain braes, 129. Dalmahoy area, 79. Shale, 6, 70, 72, 79. Dalmeny and Queensferry Shale-fields, 71-77. Dam Shale, 26, 33. Deans and Living.ston Shale-fields, 33-37. Decay of timber, 118. Dechmont Arch, 12, 31, 60. Deugnon, v., 137. Diagram showing process of manu- facture, 188. Distillation of ammonia water, 177. oil-shale by igneous rocks, 168. Drake, E. L., 137. Drawing shale, 128. Drumshoreland, diamond bore at, 46. Duddingston Section. 67. Shale-field, 65-71. Dunnet Marls, 21, 37. Sandstone Group, 8, IS, 31, 36, 41, 47, 48, 49. 53, 62, 69, 73, 78, 8l, 83. Shale, 18, 21, 24, 30, 31, 32, 33, 3(5, 37, 41, 47^49, 54, 58, 62, 71, 74, 75, 77, 78, 81, 8.5, 86. Oakbank Pit. 116. Duntarvie Castle, 55. Dykefoot, Dunnet Shales at, 21. Dykes, sandstone, 69. East Broadlaw, limestone at, 57-58. Ecclesmachan District, 56-60. — — neck at, 13, 57. Enrichment of gas, 193. Explosives used, quantity and cost of gunpowder and fuse, 107, 103. Fan ventilation, 123-125. Fault, Blackbrae, 26, 27. Brotherton, 20. .Calder, 11,42. Ecclesmachan, 56. Langside-Blackbum, 30, 31. — Mddleton HaU, 11, 33, 34. — — Murieston, 11, 27, 29, 37, 42. Ochiltree, 12, 52. 56, 63, 65, 71, 75, 77. Winchburgh, 12, 52. 59. Fells Limestone, 9, 18, 22, 2.5, 50, 82. Shale, 18, 22, 23, 25, 32, 33, 42, 48, 50, 59, 64, 77, 86, 114. Fossils, lists of, from Mungle and Pumpherston Shell Beds, 93, 94. use of, 92. Fraser Shale, 19. Gallow-scrook, volcanic neck at, 14. Gavieside Field, 31. Gases and ventilation, 119. Gas oils, 136. — • — • permanent, of retorts, 189. recovery from stills, 185. Geikie, Sir A., 1, 8. General chemistry of the shales, 157. Grange Sandstone, 81, 83. " Grey Shale," 26, 27. Gypsum veins in shale, 45. Hailes Sandstone, 6. Harbumhead Hill, diamond bore near, 17. Hartwood, 20. Index. 197 Haulage, electric, 133. endless rope, plan and elevation of, 133. engine, 131. Henderson's ammonia column still, 177, 179. • continuous boiler stills, 186. sweating apparatus, 183. retorts, 172, 174. Hermand, 9, 21, 22, 24. History of oil-shale industry, 136. HopetounHouse,shoresectionsnear,66. Shales, 65. Sill, 67. Horses (haulage), 128. Houston Coal, 9-10, 19, 23, 26, 32, 33, 37, 42, 51, 56, 59, 64, 77, 82, 86. Marls, 10, 19, 23, 42, 51, 56, 59, 64, 77. Wood SiU, 44, 48, 49. Humbie and Winchburgh District, 52- 56. Dunnet Shale and Binny Sand- stone at, 55. Hurlet Coal, Renfrewshire, shale above, 142. Illieston, bores at, 45. IncUned shaft winding, 133. Inclines, self-acting, 128. IngUston and NewUston Shale-fields, 77-79. Intermediate oils, 193. Inverkeithing District, 82-84. Ironstone, blackband, 52. KERoaEN, 143. ^ nature and origin of, 163. Kingscavil, sandstone at, 65. Kirkliston, 77. Arch, 12, 77. Laboratory tube results, 145. Langside-Blackbum Fault, 30, 31. Leith, Water of, 6. Level di'iving, 101. cross-cuts, 105. " ends " or " upsets," 105. labour notes, 105. — method of boring, 102. shots, 105. bursters, 102. ordinary, 103. brairders, 102. mids and tops, 103. Levenseat Shale, 142, 146, 155. Limefield House, section near, 24. Limestone, Burdiehouse. {See Burdie- house.) Barracks, 8, 30, 31, 33, 36, 37, 41, 47, 50, 62 (footnote). Cobbinshaw Main, 19-20, 26, 27, 33,62. :-* .10 Fells, 9, 18, 22, 25, 50, 82. Riccarton, 65. 13 Liquid fuel, 194. Livingston and Deans Shale-fields, 33- 37. Lochgelly ironstone, 142. Longwall face, cross section and plan. 113. — — system, plan of shale mine, 112. working, 112. Lubricating oils, 136, 191. Maltha, 159. McLaren, Robert, H.M.. Inspector of Mines, regulations for shot-firing, 107. M'Lean Shale, Oakbank, 48, 142, 149. Marl, 10. Broxburn, 9, 18, 22, 23, 32, 41, 50, 64. Dunnet, 21, 37. ^ Houston, 10, 19, 23, 42, 51, 56, 64, 77. Methods of working, 108. removing stoops. 111. Mid-Calder District, 37-43. Shales, 98. Middleton HaU Fault, 11, 33, 34. Midhope Shale, 64-65. Millstone Grit, 3. Mine-driving, 99. — ■ — roof timbering, 100. in folded strata, 97. — — with level cross-cuts, 97. Minerals now or formerly used for oil-shale products, 141. Mode of access to oil-shales, 97. Moreau, a., 137. Mungle Shale, 19, 23, 26, 52, 142, 146. SheU Bed, 10, 19, 83, 87, 93. Murieston, Wester, 30. Fault, 11, 27, 29, 37, 42. Water section, 27-28. Naphtha, 136, 190, 192. Naphthenes, 189, 190. Natural gas in oil-shale fields, 170. Necks, volcanic, 13. — — at Binn's Hill, 13. • — Ecclesmachan, 13. ■ Gallowscrook, 14. Kirkliston, 78. — Niddry Castle, 13. Society, 71. Newfarm, 39, 42. NewUston, Dunnet Shale at, 77-78. Newpark, 28. New South Wales Shale, 162. Newyearfield, diamond bore at. 35. Nitrogen m shale, 148, 149, 1.57, 158. Oakbank Bio Shale, 142, 147. Oakbank Pit, 116. and bore, section of, 39-40. Wee Shale, 142, 147. Ochiltree Fault. 12. 52. 56, 63, 66, 71, 76, 77. 198 Index. Oils, burning, 139, 186, 191. intermediate, 136, 193. lubricating, 136, 191, 193. Oil-shale, distillation of by igneous rocks, 168. — Group, distribution of, 4-7. physical characters of, 7. process of manufacture, 166. strata, proving of, 87-90. Oil, yield of in relation to depth, 144. Old Red Sandstone at Selms, 42. Ooliths at 'Rosyth, 83. Overfold, 96. Ozokerite candles, Binny, 143. Paper shale, 86. Paraffin, soUd, 130, 191, 193. sweating apparatus, 183. Pardovan, sandstone at, 65. Pennsylvania oil-wells, 137. Pentland Arch, 13, 80. Peruvian guano, 137. Petroleum, imports of, 141. 'in oil-shale, origin of, 164, 167. 169, 170. ^ native, 166-170. statistics, 138-141. Phenols, 189. Philpstoun and Champfleurie Shale- fields, 60-65. Plan and section of highly-inclined stoops, 109. ^ stoop and room, 108. Playfair, Lord, 136. Polbeth Shale-field, 30. Port Edgar Ash, 61, 62, 69, 73, 74. • railway cutting, section at, 73. Prices of products, 137, 139. Products of manufacture, 136, 189. Properties of products of manufacture, 189-194. Proving of oil-shale strata, 91-94. Proximate composition of shale, 157. Pumpherston Arch, 12, 53, 60, 67. Oil Co., 98. Shale-field, 43-48, 114. Shales, 17, 21, 29, 33, 34-35, 39, 44-46, 54, 58, 61, 66, 67, 75, 77, 81, 85. Shales, section of, at Pumphers- ton, 44. Shell Bed, 10, 35, 66, 67, 70, 72, 77, 81, 92, 94. Pumping water : direct acting pumps, hydraulic pumps, and electric pumps, 127. Pyridine Bases, 189. QUEENSFERRY AND DaLMENY ShALE- FIELDS, 71-77. Cements, 66, 67, 69, 70, 72, 77. shore section at, 70. Quinohne Bases, 189. Raeburn Shale, 19, 23, 26, 33, 52, 64, 142, 146. Railways for hutches, 128. Raw and Raw Camps limestone quarries, 40. Refinery, the, 180. 'Operations, 181. distillations and treatments, 181-189. — — separation of solid paraffin, 181. • — — stills, 185. Results of shale distillation, 177. Retorts : Bryson's, 175. condensers, 176. development of, 171. — Henderson's, 172, 174. horizontal, 171. • old vertical, 172. .permanent gases of, 189. Yoimg and Beilby, 173. Riccarton, marine limestone at, 65. Roof and cro^\'n tree, 118. steel girder and vertical props, 11 8. • and vertical props, 118. Rosyth, Burdiehouse Limestone and ooliths at, 83. section at, 83. Russian petroleum industry, 138. — — production of petroleum, 141. Sandstone dykes in limestone, 69. Seafield Shale-field, 32, 33. Search for shale, 95. Sections, disturbed gi'ound, 96. Dunnet Shale, method of work- ing, Mid-Calder, 116. trial shaft and cross-cut, 97. working oil-shale in steps, 115. — — working vertical seams of shale, 117. Selms, comstone at, 42. Shale, Barracks, 37, 143. Big, Oakbank, 142, 147. Broxbm-n, 142, 148, 157, 158. Curly, Broxburn, 142, 145, 147. Dunnet, 143, 149, 150, 158, 159. Fells, 142, 146. Fraser, 142. Grey, Addiewell, 142, 146. Ust of oil producers, 141-143. Lower Wild, Oakbank, 142, 149. Mungle or Steuart, 142, 146. Oakbank New, 143, 151. Pumpherston No. 1, Jubilee, 143, 151. No. 2, Maybrick, 143, 151. No. 3, Curly, 143, 151. No. 4, Plam, 143, 152. No. 5, Under, 143, 152. Raebum or Damhead, 142. — — Raebum, 142. • above Hurlet Coal, 142. results of the distillation of, 136, 177. Index. 199 Shale-measures, geological position of, 3. ^ naphthas, 136, 190. Shales, chemical composition of chief. 143. — — and solvents, 159, 164. Shell Bed, Mungle, 10, 19, 83, 87, 93. Pumpherston, 10, 35, 66, 67. 70, 72, 77, 81, 92, 94. Shot-firing, 107. SiUs, dolerite, 14-15. contact alteration by, 15. 50, 55, 59. Sinking carriage, 101. pumps, 101. Solubihtv of shale and bitumens, 159. 164. Special methods of working, 115. Spontaneous combustion prevented by mineral oils, 193. Spragging shale, methods of, 114. Statistics, 138-141. prices of products, 137, 139. Still coke, 194. grease, 193. Stills, 185-189. connected boiler, 186. heavy oil, 187. residue, 185, 186. " Stoop and room," 108. Straiton, section at, 84. Sulphate of ammonia, 136, 140, 194. Sulphur in shale, 159. Swinebum diamond bore, 55, 56. Taebrax, 18, 19. Tars from crude oil, chemical nature of, 189. " Thick " Shale, 23, 25. " Thornton's " Shale, 25. Timbering of levels, 118. TorbanehiU Mineral, 1, 137, 142, 146, 155, 159-161. Torbanite of N.S. Wales, 162. Tuffs, volcanic, 13. ' with Houston Coal at Dal- meny, 77. Two-foot Ash, 13, 59, 64. Coal, 19, 23, 26, 31, 37, 51, 59, 64. Ultimate composition of shale, 157. Underground haulage, 128. United States Geological Survey, 140, 169. Ventilation and gases, 119. hand fan, 124. fans, 123. of longwall workings, 126. mine-driving, 101. Ventilation of workings, 123. plan and elevation of trap-door, 126. of "stoop and room" workings, 127. Vertical seams, working of, 117. shaft, j\Iid-Calder, 98. Viscosimeters, 192. Volcanic ash, etc. {See Ash, Neck, Lavas, etc.) Wardie Shales, 6. Washers for acid and soda, 186. West Calder Shale-field, 20-28. Vv^estfield, Fife, 142. Shale, Rutherglen, 146. Westwood, diamond bores at, 15. Whitehouse Point, shore sections at, 70. WiESMANN, A., & Co., 137. Wilson, J. S. Grant, 2, 63, 71. Wilsontown, 16. Winchburgh and Humbie District, 52- 56. Fault, 12, 52, 59. Working seams close to each other, 114. Wyndford diamond bore, 15, 49. Yield of crude oil and sulphate of AMMONIA, 146-153. Addiewell Grey Shale, 146. Airdrie Shale, 146. — ■ Barracks Shale, 143. Broxburn Curly Shale, 145, 147. Grey Shale, 145, 147. Shale, 145, 148. Dunnet Shale, 149-151. Fells Shale, 146. ■ Levenseat Shale, 146, 155. Mungle Shale, 146. — — • — Oakbank Big Shale, 147. Lower Big Shale, 147. ^— M'Lean Shale,149. New Shale, 151. Wee Shale, 147. Wild Shale, lower, 149. ■ Pentland Shale, 148. — • — ■ — Pumpherston Shales, 151-153. Raebum Shale, 146. — — TorbanehiU Mineral, 146. Yield of oil in relation to depth, 144. YouNO, James, 136, 137. Young's retort, 171. Plate I. FOSSILS FROM SCOTTISH OIL-SHALE STRATA. Figs 1-4 Fpom Ihe Mungle SKell-Bed. Figs 5 -8a In, and close lo, the Pumphepslon Shell-Bed, (iff J.4a 1 II mill Ii' 12 Figs 9-14b Common Fossils. (6230?) 31751-66 lOOO 2/12 BANKS & CO., LTD. Plate H C08BINSHAW ■?J'^fi£?'J( F££T ^00_ 900 !2eo m ItOO '-iM 2000 2*0^ IS 00 30OO JiS. Jf.C. miHi X^ BED o.sr n CAR LOPS s.s. . ASH ^ H.C. \<-^-\ D.S. w.s. BXS. if.S.'i C.OK cnosi \BURNTISLAND ' LofF.S. B.S. ''a.5.' c.s: B.L. ^r EOGAPt) LS'' 'LS. CSBBI/ LS. rt.C./,' c. : F.Si ' ,BYSA. D.S. I 3-L. LS. LP.S. Mf.HINE 3M£LL a£0 Q.S.i?DAL.S.) '^^'^^IGNEOUS ttOCKS aONJATITE. BK.D a-o.s. MARINE SHELL BED AbbPTiviations- C. L Cobbinshaw V.\m&s\xin^G//me/'too ^t Str^donj BBi Black Band Iponstone. R S. Raebupn Shale. MID.S. Midhope Shale. M.S Mungle Shale. 2'C. Two-Foot Coal. Pa. S Paper Shale faiStrayim oo/yj G- S. Qp&y Shale. H.C. Houston Coal. r S. Fells Shale LofFS. Limestone oF Fells Shale. B.S. Broxburn Shale. CH.S. ChampFleupie Shale. B"^ Sa Binny Sandstone D S. Dunnet Shale N.S. New Shale U D.S Under Dunnet Shale B*^s L. Barracks Limestone. C S Camps Shale B.L Burdiehouse Limestone PS Pumpherston Shale Q.CEM Queensferry Cennents. DAL S. Dalmahqy Shale OS. Oil Shale C. Coal LS. Limestone. LSTS. Limestones. (^0231') 3I7SI 8B lOOO 2 12 BANKS «, CO., LTD. Plate H. COBtlHSHAW . C ALDCK ■ MS. '■ ^ IXS.I.. jfC. t- mN6S Tt)H£ "^ ^.^.f.^. '^ COMPARATIVE VERTICAL SECTIONS OF SCOTTISH OIL-SHALE FIELDS. DRUMSHOflELIi NO PH ILFST OUN fUM PHEK STON MIO CALaE.fi m^^' qUEENSFSKKy * ' WM ' DUO OINGS TO/v ' D.S. t^at it''iml If." OS.I'OAL.S.) P, Uvuul SHCiL BCO i^ni^ASH fJ^ICNEOUS ROCKS ^buhntisland BYSA D.S. Abbrsviabions - C.L Cobbinshaw hmtstant^Oi/mrj^n ^ Stvilm/ B B I Black Bjnd Ironstone R S Raeburn Shale MIDS, Midhope Shale MS Mungle Shale 2C. Two foot Coal Pa S Paper Shale ,V.&/w/^