THE GAS ENGINEER'S POCKET-BOOlt COMPRISING BELATING TO THE MANUFACTURE, DISTRIBUTION, AND USE OF COAL GAS AND THE CONSTRUCTION OF GAS WORKS BY HENKY O'CONNOE FELLOW OF THE ROYAL SOCIETY, EDINBURGH ASSOCIATE MEMBER OF THE INSTITUTION OF CIVIL ENGINEERS PAST PRESIDENT OF THE SOCIETY OF ENGINEERS THIRD EDITION, REVISED LONDON CROSBY LOCKWOOD AND SON 7, STATIONERS' HALL COURT, LUDGATE HILL 1907 Library BIIADBURY, AONXW, * CO. LD., POINTERS, LONDON AND TONBRIDOK. TO HIS OLD CHIEFS CORBET WOODALL, ESQ., M.lNST.C.E. SIR GEORGE LIVESEY, M.lNST.C.E. GEORGE CARELESS TREWBY, ESQ., M.lNST.C.E. IN ACKNOWLEDGMENT OF MUCH VALUABLE INFOEMATION RECEIVED FROM THEM BY THE AUTHOR DURING HIS WORK UNDER THEIR DIRECTION HENRY O'CONNOR 274327 PREFACE. IN placing this compilation before his readers and in particular, his brother Engineers of the Gas Industry it may not be out of place for the Author to indicate the circumstances which have led, in the first instance, to the preparation of the Tables, Notes, and other matter comprised in the volume, and now to their issue in the present form. Having frequently during the course of his professional career experienced the want of any book containing those numerous tables, data, &c., which, with the spread of engineering knowledge, are every day becoming more and more necessary to the Gas Engineer for reference, he has for many years been in the habit of making and preserving, for his own use, full notes from every available source. These notes have formed the basis of the present work, and the fact that they were originally intended only for his own personal use has rendered it in many cases well-nigh impossible for the Author to acknowledge the sources of his information. He desires, however, to express here his indebtedness to both the Journal of Gas Lighting and the Gas World, whose full and careful reports, given from time to time, of papers read and discussions held at the various meetings of Engineering Societies, at which questions con- cerning the Gas Industry have been under review, have afforded him the means of obtaining a considerable portion of the matter here presented. VI PKEFACE. In deciding the plan upon which the matter should be arranged, it appeared to the Author that the most suitable method was to take the various processes consecutively as they occur in the course of Gas-making, and to treat of the Construction of the Works separately from the Manufacture of the Gas. The diagrammatic form of tabulating has been followed wherever it seemed to be preferable, and the dimensions of the volume have in consequence been increased from the ordinary pocket-book size, so as to enable the diagrams to be better seen and read. The Tables have been most carefully checked, and every precaution taken to render them as accurate as possible. Should, however, any error be detected in them, the Author will feel much obliged for information of the fact ; while he will welcome any communication upon the subject generally with which readers may be pleased to favour him. H. O'C. Edinburgh, 1897. NOTE TO THIRD EDITION. IT is very gratifying that another edition of the POCKET- BOOK has been speedily called for, and the opportunity has been taken of amending and supplementing the text of the book where advisable, and of bringing the Statutory Regula- tions for Testing the Illuminating Power and Purity of Gas up to date, as revised August, 1906. TABLE OF CONTENTS. GENERAL CONSTRUCTING MEMORANDA. General Mathematical Tables. PAGE Squares, Cubes, Square Roots, Cube Roots, Reciprocals and Logarithms 1 Logarithms, description of 23 Area and Circumferences of Circles in hs, ^ths, and ^ths . 24 Properties of Circles . . . 41 Weights and Measures 42 Decimals of 1, cwt., mile, year, inch, foot, lb., ton . . . 45 Equivalent English and Metric Weights and Measures . . 56 Cubic Feet into Cubic Metres, and the reverse . . . 58 Sizes of Drawing Paper, and Colours used in Drawings . . 59 Weights of Materials 60 Foundations 64 Footings 65 Damp Courses and Inverted Arches 66 Brickwork notes 67 Courses (diagrams) 70 Scaffolding notes 72 Strength of Mortar 72 Portland Cement notes 73 Facing and Pointing 74 Resistance to Crushing 75 Stonework notes 76 Painting notes 76 Glazing notes . . . 77 Roof Coverings . . 78 Proportions of Treads and Risers to Staircases . . . .81 Viii CONTENTS. X>AGE Timber notes 81 Breaking Loads on Wooden Pillars (diagram) .... 84 Safe Loads on Wooden Beams and Joists . , . . 85, 86 Dead and Live Loads 87 Water Power, Specific Heats 88 Radiant Heat 89 Factors of Safety ft . . 89 Weight of Flat Rolled Iron 90 Birmingham and American Gauges 96 Weight of Zinc, Thickness of Tin Plates . . :. . . 96 Tin-Plates, Dimensions and Weights . .. , . .-.. . 97 Copper Nails 98 Corrugated Iron Roof Sheeting 98 Electrical Conductivity and Melting Point of Metals . . 98 Castings 99 Case- Hardening 100 Breaking Strength, Elastic Strength, and Modulus of Elasticity 101 Proportions, Strengths, and Weights of Bolts, Nuts, and Washers 102 and Strengths of Riveted Joints . . . . 104 Strengths, and Weights of Rivets . . . .106 Strengths of Ropes and Chains . 109 Testing Iron and Steel . . . '/. . . . . .113 Weights of Cast Iron Pipes 115 Average Dimensions of Socket and Flanged Connections . 116, 118 Diagrams of Weight of Cast Iron Pipes 120 Proportions of Pipe Flanges 122 Weight of Lead and Composition Pipes ... 123 Whitworth Screw Threads . . . .'_.'." .125 Weights of Sheet Metals (diagram) , . . \ . . 128 Weight of Half-round Iron end Sheet Brass ..... . . 130 Weight of Round and Square Iron and Steel . . ... 131 Wrought Iron Girders 132 Diagram of proper Size of Rolled Joists ... . . 134 Moments of Inertia and Resistance of Beams . .136 Girders 138 Plates . . 140 Least Radius of Gyration 141 Arches 143 Unloading Materials and Storage (Construction). Space required by different Coals 145 Coal Stores 145, 148 CONTENTS. IX PAGE Stabling and Koads 146 Railways and Locomotives 148 Crane Hooks . 150 Retort House (Construction). Hydraulic Cranes 151 Conveyors and Grabs 152 Fire-Clays and Bricks 152 Retorts 153 Dimensions of Retort Houses . . . . . . .154 Settings 155 Hydraulic Mains . .159 Ascension Pipes 160 Hydraulic Main Valves 161 Connections in Gas Works 162 Condensers (Construction). Dimensions necessary 163 General notes 163 Loss of Heat in Air and under Water 164 Deposition of Tar 165 Tar and Liquor Tanks . 165 Boilers, Engines, Pumps, and Exhausters (Construction). Horse-power and Space required .... . . 166 for 24-inch Pressure 167 to pass Gas 167 Steam Pressures 169 Losses in Boilers and Electric Plants 169 Proportions of Boilers 170 Strength 171 Safety Valves .176 Boiler Chimneys 176 Lightning Conductors ..." 181 Steam and Exhaust Pipes 182 Distance between Bearings of Shafts (diagram) . . . 183 Notes on Pumps 184 Flywheels and Toothed Gearing 187 Belt Gearing 188 X CONTENTS. PAGE Rope Gearing . . . 189 Gas Engines 190 Values of Explosive Mixtures 193 Scrubbers and Washers (Construction). Dimensions necessary . . . . * . . ,-. . .195 Absorptive Power of Water . . . . ;.>-; . . . 196 Reaction of Cyanides . . _..... *;-,,* 196 Purifiers (Construction). Area required . . . . .. . . . . . 197 Arrangements of Purifier Connections . .; -< 199 Claus Process . . . . . ... .**> i*7 ; r>: . . 201 Gasholder Tanks (Construction). General notes and Natural Slopes of Earths . ".-' ... 202 Resistance of Earth Backing . . ... . . . 204 Formula for Strength of Tank Walls . . . .";'.- . 205 Pressure of Water against a Tank Side . - . : : ;/ . 206 Thickness of Sheets for Wrought Iron Tanks (diagram) . . 208 Concrete Tank Walls . . j^ 209 Gasholders (Construction). General notes . . . . - :;,*^7 /*? ,^ n ] ^ , 211 Rivets required for different Thicknesses of Plates . . . . 212 Force of the Wind . , . . ."","....'..".. . - 215 Allowance for Wind and Snow . . . . ' ! _. ......'/-'. 217 Guide Framing notes - 220 Diagram of Pressures thrown by Holders . . , . . . . 221 Formulae for Multipost Gasholders . ... . ... 222 Cantilever ., .. ., .... / . 223 Notes on Cups and Grips ... .. .. ./ v im>S; ^^ Strains on Gasholder Sheeting . , ^ .- . 225 Workshop Notes. Station Meters 229 General Dimensions 230 CONTENTS. atl MANUFACTURING. Storing Materials. PAGE Stacking Coal . 231 Igniting Point of various Coals 232 Retort House (Working) Carbonising notes 233 Effects of Temperature on Distillation 235 Make of Gas per Hour 237 Climatic Effects on Carbonisation 239 Generator Furnaces 240 Regenerator Furnaces 241 Labour required for Carbonising 245 Curing Stopped Ascension Pipes 246 Table of Effects of Heat 247 Pyrometers 249 Residuals from Coal . . 251 Gas from different Substances 253 Condensing Gas. General notes 255 Tests for Napthalene 256 Exhausters, &c. Effects of Air on Gas 258 Combustion of Fuels in Boilers . ,,..., 259 Boiler Incrustations . .... 261 Test for Pure Water .... . 261 Washing ana Scrubbing. Quantity of Ammonia removed 262 General notes ... 263 Cyanogen ... 265 xii CONTENTS. Purification. PAGE Analyses of Oxides 267 Notes on Oxide Purification 269 Lime . 270 Kemoval of Sulphur Compounds 272 Carbon Dioxide 272 WeldonMud 274 Revivification in situ 275 Oxygen in Purification 276 Arresting Cyanogen Compounds 277 Composition of Purified Illuminating Gas 277 Gasholders (Care of). Diffusion of Gases 279 Painting notes 279 Distributing Gas. Flow of Gases through Pipes 281 Diagrams of Distributing Power of Pipes 282 Lead required for Jointing 285 Dimensions of Pipes 286 Jointing Material . . . 288 Dimensions of Socket Joints 289 Testing Mains 291 Rack and Pinion Valves 293 Service Pipes ' . . . . . 296 Wrought Iron Tubing 297 Diagram of Comparative Pressures 299 Napthalene HOI Cold Enrichers 301 Diagram of the Number of Cubic Feet per Id. for different prices per 1,000 Cubic Feet 303 Diagram of Comparison of Prices of Gas in Sterling and French Moneys 304 Relative Values of Illuminating Agents . ... 305 Vitiation of Air 307 Height of Lamps 309 CONTENTS. xiii PAGE Ventilation notes 311 Comparative Costs of different Lights 313 Gas Stove notes 314 Warming by Steam 315 Heats of Fires 317 Balloons 318 Wet Meters . . 319 Dry Meters . 320 Testing. Elementary Bodies 322 Air. Gas, and Water . . 323 Saturated Hydrocarbons 325 Tension of Aqueous Vapour 327 Explosive Mixtures ......... 329 Lbs. Water heated and C02 produced 331 Expansion and Weight of Water 333 Melting Points 334 Boiling Points . 335 Specific Heats 336 Freezing Mixtures 337 Radiation of Heat 339 Heat Units evolved by different Substances 341 To Prepare Chemical Indicators 342 Normal Solutions 344 TwaddeU 346 Burners 348 Composition of Coal Gas 349 Comparative Analysis of Coal and Carburetted Water Gas . . 352 Values of Illuminating Gases 353 Illuminating Values of Hydrocarbons 355 Temperatures of Flames 357 Photometers 358 general notes 360 Diagram for Correcting for Irregular Burning of Candles . . 362 Gas. . . 364 of Tabular Numbers 366 for Correcting for Tabular Numbers .... 368 Harcourt's 1- Candle Pentane Unit 369 Hefner Unit . 370 CONTENTS. Dibdin's 10- Candle Unit . . . . t . . . . 371 To Test Lime . . . . . . .' . .372 Oxide 373 Ten per cent. Acid Solution 375 Diagram for use with Harcourt's Colour Test . . . . 377 Specific Gravities of Gases . . . ..... . 379 Testing Coals . . . . . . . . . . . 380 Diagrams showing actual Grains Sulphur from Grains BaS0 4 . 383 Enriching Processes. Cost of Enrichment . . ... . . . . 385 Benzol as an Enricher . . . . . >:,"< , 387 Acetylene . . . . . . .' -* r Xv '- 39 Carburetted Water Gas Plant . . . ' . . . . 393 Calorific Value of Water Gas . ~ " . , 399 Dowson Gas . . . . . . '.'';" . ... 400 Peebles Process . . . js .^ ',-- ,vl ' - .402 Suction Gas Producer . . . 403 Products Works. Sulphate Making ' v . 404 Coal Tar Products - 5 , .; n -406 Analysis of Coal Tar f v , Supplementary. Statutory and Official Regulations for Testing the Illuminating Power and Purity of Gas . . . . .; s ., _ . . 410 Notification of Gas Referees for 1906 . . . ... 412 Ten-candle Pentane Lamp . . The Table Photometer . The Metropolitan Argand No. 2 425 Tabular Numbers . . . .* ' .* A ^- s \ l . . . 426 Test for Sulphuretted Hydrogen 428 The Gas Calorimeter 430 Gas Referees' Standard Burner 435 Table giving Illuminating Power of Gas 436 English, French and German Glossary of Terms used in Gas Works . 437 THE GAS ENGINEEK'S POCKET-BOOK. GENERAL MATHEMATICAL TABLES. No. Square. ; Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 1 1 1 i-ooo 1-000 1-000000 000000 301030 2 4 8 1-414 1-259 500000 301030 176091 3 9 27 1-732 1-442 333333 477121 124939 4 16 64 2-000 1-587 250000 602060 96910 5 25 125 2-236 1-709 200000 698970 79181 6 36 216 2-449 1-817 166667 778151 66947 7 49 343 2-645 1-912 142857 845098 57992 8 64 512 2-828 2-000 125000 903090 51153 9 81 729 3-000 2-080 111111 954243 45757 10 100 1,000 3-162 2-154 100000 000000 41393 11 121 1,331 3-316 2-223 090909 041393 37788 12 144 1,728 3-464 2-289 083333 079181 34762 13 169 2,197 3-605 2-351 076923 113943 32185 14 196 2,744 3-741 2-410 071429 146128 29963 15 225 3,375 3-872 2-466 066667 176091 28029 16 256 4,096 4-000 2-519 062500 204120 26329 17 289 4,913 4-123 2-571 058824 230449 24824 18 324 5,832 4-242 2-620 055556 255273 23481 19 361 6,859 4-358 2-668 052632 278754 22276 20 400 8,000 4-472 2-714 050000 301030 21189 21 441 9,261 4-582 2-758 047619 322219 20204 22 484 10,624 4-690 2-802 045455 342423 19305 23 529 12,167 4-795 2-843 043478 361728 18483 24 576 13,824 4-898 2-884 041667 380211 17729 25 625 15,625 5-000 2-924 040000 397940 17033 26 676 17,676 5-099 2-962 038462 414973 16391 27 729 19,683 5-196 3-000 037037 431364 15794 28 784 21,952 5-291 3-036 035714 447158 15240 29 841 24,389 5-385 3-072 034483 462398 14723 G.E. GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 30 900 27,000 5-477 3-107 033333 477121 14241 31 961 29,791 5-567 3-141 032258 491362 13798 32 1,024 32,768 5-656 3-175 031250 505150 13364 33 1,089 35,937 5-744 3-207 030303 018514 12965 34 1,156 39,304 5-830 3-239 029412 531479 12589 35 1,225 42,875 5-916 3-271 028571 544068 12235 36 1,296 46,656 6-000 3-301 027778 556303 11899 37 1,369 50.653 6-082 3-332 027027 568202 11582 38 1,444 54,872 6-164 3-361 026316 579784 11281 39 1,521 59,319 6-244 3-391 025641 91065 10995 40 1,600 64,000 6-326 3-419 025000 602060 10724 41 1,681 68,921 6-403 3-448 024390 612784 10465 42 1,764 74,088 6-480 3-476 023810 623249 10219 43 1.849 79,507 6-557 3-503 023256 633468 9985 44 1,936 85,184 6-633 3-530 022727 643453 9760 45 2,025 91,125 6-708 3-556 022222 653213 9545 46 2,116 97,336 6-782 3-583 021739 662758 9340 47 2,209 103,823 6-855 3-608 021277 672098 9143 48 2,304 110,592 6-928 3-634 020833 681241 8955 49 2,401 117,649 7-000 3-659 020408 690196 8774 50 2,500 125,000 7-071 3-684 020000 698970 8600 51 2,601 132,651 7-141 3-708 019608 707570 8433 52 2,704 140,608 7-211 3-732 019231 716003 8273 53 2,809 148,877 7-280 3-756 018868 724276 8118 54 2,916 157,464 7-348 3-779 018519 732394 7969 55 3,025 166,375 7-416 3-802 018182 740363 7825 56 3,136 175,616 7-483 3-825 017857 748188 7687 57 3,249 185,193 7-549 3-848 017544 755875 7553 58 3,364 195,122 7-615 3-870 017241 763428 7424 59 3,481 205,379 7-681 3-892 016949 770852 7299 60 3,600 216,000 7-745 3-914 016667 778151 7179 61 3,721 226,981 7-810 3-936 016393 785330 7062 62 3,844 238,328 7-874 3-957 016129 792392 6949 63 3,969 250,047 7-937 3-979 015873 799341 6839 64 4,096 262,144 8-000 4-000 015625 806180 6733 65 4.225 274,625 8-062 4-020 015385 812913 6631 66 4,356 287,496 8-124 4-041 015152 819544 6531 67 4,489 300,763 8-185 4-061 014925 826075 6434 68 4,624 314,432 8-246 4-081 014706 832509 6340 69 4,761 328,509 8-306 4-101 014493 838849 6249 70 4,900 343,000 8-366 4-121 014286 845098 6160 71 5,041 357,911 8-426 4-140 014085 851258 6074 72 5,184 373,248 8-485 4-160 013889 857332 5991 73 5,329 389,017 8-544 4-179 013699 863323 5909 74 5,476 405,224 8-602 4-198 013514 869232 5829 GENERAL MATHEMATICAL TABLES. , Square Cube Recip- Loga- Differ- No. Square. Root. Root. rocal. rithm. ence. 75 5,625 421,875 8-660 4-217 013333 875061 5753 76 5,776 438,976 8-717 4-235 013158 880814 5677 77 5,929 456,533 8-744 4-254 012987 886491 5604 78 6,084 474,552 8-831 4-272 012821 892095 5532 79 6,241 493,039 8-888 4-290 012658 897627 5463 80 6,400 512,000 8-944 4-308 012500 903090 5395 81 6,561 531,441 9-000 4-326 012346 908485 5329 82 6,724 551,368 9-055 4-344 012195 913814 5264 83 6,889 571,787 9-110 4-362 012048 919078 5201 84 7,056 592,704 9-165 4-379 011905 924279 5140 85 7,225 614,125 9-219 4-396 011765 929419 5079 86 7,396 636,056 9-273 4-414 011628 934498 5021 87 7,569 658,503 9-327 4-431 011494 939519 4964 88 7.744 681,472 9-380 4-447 011364 944483 4907 89 7/J21 704,969 9-433 4-461 011236 949390 4853 90 8,100 729,000 9-486 4-481 011111 954243 4798 91 8,281 753,571 9-539 4-497 010989 959041 4747 92 8,464 778,688 9-591 4-514 010870 963788 4695 93 8,649 804,357 9-643 4-530 010753 968483 4645 94 8,836 830,584 9-695 4-546 010638 973128 4596 95 9.025 857.375 9-746 4-562 010526 977724 4547 96 9.216 884,786 9-797 4-578 010417 982271 4501 97 9,409 912,673 9-848 4-594 010309 986772 4454 98 9,604 941,192 9-899 4-610 010204 991226 4409 99 9,801 970,299 9-949 4-626 010101 995635 4360 100 10,000 1,000,000 10-000 4-641 010000 000000 4321 101 10,201 1,030,301 10-049 4-657 009901 004321 4279 102 10,404 1,061,208 10-099 4-672 009804 008600 4237 103 10,609 1.092,727 10-148 4-687 009709 012837 4196 104 10,816 1,124,864 10-198 4-702 009615 017033 4156 105 11,025 1,157,625 10-246 4-717 009524 021189 4117 106 11,236 1,191,016 '10-295 4-732 009434 025306 4078 107 11,449 1,225,043 10-344 4-747 009346 029384 4040 108 11,664 1,259,712 110-392 4-762 009259 033424 4002 109 11,881 1,295,029 10-440 4-776 009174 037426 3967 110 12,100 1.331,000 10-488 4-791 009091 041393 3930 111 12,321 1,367,631 10-535 4-805 009009 045323 3895 112 12,554 1,404,928 10-583 4-820 008929 049218 3860 113 12,769 1,442,897 10-630 4-834 008850 053078 3827 114 12,996 1,481,544 10-677 4-848 008772 056905 3793 115 13,225 1,520,875 10-723 4-862 008696 060698 3760 116 13,456 1,560,896 10-770 4-876 008621 064458 3728 117 13,689 1,601,613 10-816 4-890 008547 068186 3696 118 13,924 1,643,032 10-862 4-904 008475 071882 3665 119 14,161 1,685,159 10-908 4-918 008403 075547 3634 B 2 GAS ENGINEER'S POCKET-BOOK. No. Square. pnhA Square Cube - Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 120 14,400 1,728,000 10-954 4-932 008333 079181 3604 121 14,641 1,771,561 11-000 4-946 008264 082785 3575 122 14,884 1,815,848 11-045 4-959 008197 086360 3545 123 15,129 1,860,867 11-090 4-973 008130 089905 3517 124 15,376 1,906,624 11-135 4-986 008065 093422 3488 125 15,025 1,953,125 11-180 5-000 008000 096910 3461 126 15,876 2,000,376 11-224 5-013 007937 100371 3433 127 16,129 2,048,383 11-269 5-026 007874 103804 3406 128 16,384 2,097,152 ;11-313 5-039 007813 107210 3380 129 16,641 2.146,689 jll-357 5-052 007752 110590 3343 130 16,900 2,197,000 11-401 5-065 007692 113943 3328 131 17,161 2,248,091 11-445 5-078 007634 117271 3303 132 17.424 2,299,968 11-489 5-091 007576 120574 3278 133 17.689 2,352,637 11-532 5-104 007519 123852 3253 134 17^56 2,406,104 11-575 5-117 007463 127105 3229 135 18,225 2,460,375 11-618 5-129 007407 130334 3205 136 18,496 2,515,456 11-661 5-142 007353 133539 3182 137 18,769 2,571,353 11-704 5-155 007299 136721 3148 138 19,044 2,620,872 11-747 5-167 007246 139879 3136 139 19,321 2,685,619 11-789 5-180 007194 143015 3113 140 19,600 2,744,000 11-832 5-192 007143 146128 3091 141 19,881 2,803,221 11-874 5-204 007092 149219 3069 142 20,164 2,863,288 11-916 5-217 007042 152288 3048 143 20,449 2,924,207 11-958 5-229 006993 155336 3026 144 20,736 2,985,984 12-000 5-241 006944 158362 3006 145 21,025 3,048,625 12-041 5-253 006897 161368 2985 146 21,316 3,112,136 12-083 5-265 006849 164353 2964 147 21,609 3,176,523 12-124 5-277 006803 167317 2945 148 21,904 3,241,792 12-165 5-289 006757 170262 2924 149 22,201 3,307,949 12-206 5-301 006711 173186 2905 150 22.500 3,375,000 12-247 5-313 006667 176091 2886 151 22.X01 3,442,951 12-288 5-325 006623 178977 2867 152 23.104 3,511,808 12-328 5-336 006579 181844 2847 153 23,409 3,581,577 12-369 5-348 006536 184691 2830 154 23,716 3,652,264 12-409 5-360 006494 187521 2811 155 24,025 3,723,875 12-449 5-371 006452 190332 2793 156 24,336 3,796,416 12-489 5-383 006410 193125 2775 157 24,649 3,869,893 12-529 5-394 006369 195900 2757 158 24,964 3,944,312 12-569 5-406 006329 198657 2740 159 25,281 4,019,679 12-609 5-417 006289 201397 2723 160 25,600 4,096,000 12-649 5-428 006250 204120 2706 161 25,921 4,173,281 12-688 5-440 006211 206826 2689 162 26,244 4,251,528 12-727 5-451 006173 209515 2673 163 26,569 4,330,747 12-767 5-462 006135 212188 2656 164 26,896 4,410,944 12-806 5-473 006098 214844 2640 GENERAL MATHEMATICAL TABLES. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 165 27,225 4,492,125 12-845 5-484 006061 217484 2624 166 27,556 4,574,296 12-884 5-495 006024 220108 2608 167 27,889 4,657,463 12-922 5-506 005988 222716 2583 168 28,224 4,741,632 12-961 5-517 005952 225309 2578 169 28,561 4,826,809 13-000 5-528 005917 227887 2562 170 28,900 4,913,000 13-038 5-539 005882 230449 2547 171 29,241 5,000,211 13-076 5-550 005848 232996 2532 172 29,584 5,088,448 13-114 5-561 005814 235528 2518 173 29,929 5,177,717 13-152 5-572 005780 238046 2503 174 30,276 5,268,024 13-190 5-582 005747 240549 2489 175 30,625 5,359,375 13-228 5-593 005714 243038 2475 176 30,976 5,451,776 13-266 5-604 005682 245513 2460 177 31,329 5,545,233 13-304 5-614 005650 247973 2447 178 31,684 5,639,752 13-341 5-625 005618 250420 2433 179 32,041 5,735,339 13-379 5-635 005587 252853 2420 180 32,400 5,832,000 13-416 5-646 005556 255273 2406 181 32,761 5,929,741 13-453 5-656 005525 257679 2392 182 33,124 6,028,568 13-490 5-667 005495 260071 2380 183 33,489 6,128,487 13-527 5-677 005464 262451 2367 184 33,856 6,229,504 13-564 5-687 005435 264818 2354 185 34,225 6,331,625 13-601 5-698 005405 267172 2341 186 34,596 6,434,856 13-638 5-708 005376 269513 2329 187 34,969 6,539,203 13-674 5-718 005348 271842 2316 188 35,344 6,644,672 13-711 5-728 005319 274158 2304 189 35,721 6,751,269 13-747 5-738 005291 276462 2292 190 36,100 6,859,000 13-784 5-748 005263 278754 2279 191 36,481 6,967,871 13-820 5-758 005236 281033 2268 192 36,864 7,077,888 13-856 5-768 005208 283301 2256 193 37,249 7,189,057 13-892 5-778 005181 285557 2245 194 37,636 7,301,384 13-928 5-788 005155 287802 2233 195 38,025 7,414,875 13-964 5-798 005128 290035 2221 196 38,416 7,529,536 14-000 5-808 005102 292256 2210 197 38,809 7,645,373 14-035 5-818 005076 294466 2199 198 39,204 7,762,392 14-071 5-828 005051 296665 2188 199 39,601 7,880,599 14-106 5-838 005025 298853 2177 200 40,000 8,000.000 14-142 5-848 005000 301030 2166 201 40,401 8,120,601 14-177 5-857 004975 303196 2155 202! 40,804 8,242,408 14-212 5-867 004950 305351 2145 203 41,209 8,365,427 14-247 5-877 004926 307496 2134 204 41,616 8,489,664 14-282 5-886 004902 309630 2124 205 42,025 8,615,125 14-317 5-896 004878 311754 2113 206 42,436 8,741,816 14-352 5-905 004854 313867 2103 207 42,849 8,869,743 14-387 5-915 004831 315970 2093 208 43,264 8,998,912 14-422 5-924 004808 318063 2083 209 43,681 9,123,329 14-456 5-934 004785 320146 2073 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 210 44,100 9.201,000 14-491 5-943 004702 322219 2003 211 44,521 9^393,931 14-525 5-953 004739 324282 2054 212 44,944 9,528,128 14-500 5-902 004717 320336 2044 213 45,309 9,003,597 14-594 5-972 004095 328380 2034 214 45,790 9,800,344 14-028 5-981 0046-73 330414 2024 215 40,225 9,938,375 14-002 5-990 004651 332438 2010 216 40,050 10,077,090 14-090 o-ooo 004630 334454 2006 217 47,089 10,218.813 14-730 0-009 004608 336460 1996 218 47,524 10,300,232 14-704 0-018 004587 338450 19S8 219 47,901 10,503,459 14-798 0-027 004500 340444 197'.) 220 48,400 10.048,000 14-832 0-030 004545 342423 19(51) 221 48,841 10,793,801 1400-8 6-045 004525 344392 1961 222 49,284 10,941,048 14-899 0-055 004505 340353 1952 223 49,729 11,089,507 14-933 0-004 004484 348305 1943 224 50,170 11,239,424 14-960 0-073 004404 350248 1935 225 50,025 11,390,025 15-000 0-082 004444 352183 1925 226 51,070 11,543.170 15-033 0-091 004425 354108 1918 227 51,529 11,097,083 15-000 o-ioo 004405 350020 1909 228 51,984 11,852.352 15-099 0-109 004380 357935 1900 229 52,441 12,008,989 15-132 0-118 004307 359835 1893 230 52,900 12,107,000 15-105 0-120 004348 301728 1884 231 53,301 12,320,391 15-198 0-135 004329 303612 1870 232 53,824 12,487,108 15-231 6-144 004310 305488 1808 233 54,289 12,049,337 15-204 0-153 004292 367356 1800 234 54,750 12,812,904 15-297 0-102 004274 309216 1852 235 55,225 12,977,875 15-329 0-171 004255 371068 1844 236 55,090 13,144,256 15-302 0-179 004237 372912 1830 237 50,109 13,312,053 15-394 6-188 004219 374748 1829 238 50,044 13,481,272 15-427 0-197 004202 370577 1821 239 57,121 13,651,919 15-459 0-205 004184 378398 1813 240 57,000 13,824,000 15-491 0-214 004107 380211 1800 241 58,081 13,997,521 15-524 0-223 004149 382017 1798 242 58,504 14,172,488 15-550 0-231 004132 383815 1791 243 59,049 14,348,907 15-588 0-240 004115 385000 1784 244 59,530 14,520,784 15-020 0-248 004098 387390 1 770 245 00,025 14,700,125 15-052 6-257 004082 389100 1709 246 00,510 14,880,930 15-084 6-265 004005 390935 1702 247 01,009 15,009,223 15-710 6-274 004049 392097 1755 248 01,504 15,252,992 15-748 6-282 004032 394452 1747 249 02,001 15,438,249 15-779 6-291 004010 390199 1741 250 02.500 15,025,000 15-811 6-299 004000 397940 1734 251 63,001 15,813,251 15-842 6-307 003984 399074 1727 252 03,504 10,003,008 15-874 6-316 003908 401401 17-20 253 04,009 10,194,277 15-905 6-324 003953 403121 1713 254 64,510 10,387,064 15-937 6-333 003937 404834 1700 GENERAL MATHEMATICAL TABLES. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 255 65,025 16,581,375 15-968 6-341 003922 406540 1700 256 65,536 16,777,216 16-000 6-349 003906 408240 1693 257 66,049 16,974,593 16-031 6-357 003891 409933 1687 258 66,564 17,173,512 16-062 6-366 003876 411620 1680 259 67,081 17,373,979 16-093 6-374 003861 413300 1673 260 67,600 17,576,000 16-124 6-382 003846 414973 1668 231 68,121 17,779,581 16-155 6-390 003831 416641 1660 262 68,644 17.984,728 16-186 6-398 003817 418301 1655 263 69.1(59 18;i91,447 16-217 6-406 003802 419956 1648 264 69,^96 18,399,744 16-248 6-415 003788 421604 1642 2651 70.225 18,609,625 16-278 6-423 003774 423246 1636 266 70,756 18,821,096 16-309 6-431 003759 424882 1629 267 71,289 19,034,163 16-340 6-439 003745 426511 1624 268 71,824 19,248,832 16-370 6-447 003731 428135 1617 269 72,361 19.465,109 16-401 6-455 003717 429752 1612 270 72,900 19,683,000 16-431 6-463 003704 431364 1605 271 73,441 19,902,511 16-462 6-471 003690 432969 1600 272 73,984 20,123,648 16-492 6-479 003676 434569 1594 273 74,529 20,346,417 16-522 6-487 003663 436163 1588 274 75,076 20,570,824 16-552 6-495 003650 437751 1582 275 75,625 20,796,875 16,583 6-502 003636 439333 1576 276 76,176 21,024,576 16-613 6-510 003623 440909 1571 277 76,729 21,253,933 1C-643 6-518 003610 442480 1 565 278 77,284 21,484,952 16-673 6-526 003597 444045 1559 279 77,841 21,717,639 16-703 6-534 003584 445604 1554 280 78,400 21,952,000 16-733 6-542 003571 447158 1548 281 78,961 22,188,041 16-763 6-549 003559 448706 1543 282 79,524 22,425,768 16-792 6-557 003546 450249 1537 283 80,089 22,665,187 16-822 6-565 003534 451786 1532 284 80,656 22,906,304 16-852 6-573 003522 453318 1527 285 81,225 23,149,125 16-881 6-580 003509 454845 1521 286 81,796 23,393,656 16-911 6-588 003497 456366 1516 287 82,369 23,639,903 16-941 6-596 008484 457882 1510 288 82,944 23,887,872 16-970 6-603 003472 459392 1506 289 83,521 24,137,569 17-000 6-611 003460 460898 1500 290 84,100 24,389,000 17-029 6-619 003448 462398 1495 291 84,681 24,642,171 17-059 6-627 003436 463893 1490 292 85,264 24,897,088 17-088 6-634 003425 465383 1485 293 85,849 25,153,757 17-117 6-642 003413 466868 1479 294 86,436 25,412,184 17-146 6-649 003401 468347 1475 295 87,025 25,672,375 17-176 6-657 003390 469822 1470 296 87,616 25.934.336 17-205 6-664 003378 471292 1464 297 88,209 26^98,073 17-234 6-672 003367 472756 1460 298 88,804 26,463,592 17-263 6-679 003356 474216 1455 299 89,401 26,730,899 17-292 6-687 003344 475671 1450 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Cube Root. | Root. Recip- rocal. Loga- rithm. Differ- ence. 300 90.000 27,000,000 17-320 6-694 003333 477121 1415 301 90,601 27,270,901 17-349 6-702 003322 478566 1441 302 91,204 27,543,608 17-378 6-709 003311 480007 143(5 303 91,809 27,818,127 17-407 6-717 003301 481443 1431 304 92,416 28,094,464 17-436 6-724 003289 482874 142(5 305 93,025 28,372,625 17-464 6-731 OOH279 484300 1421 306 93,636 28,652,616 17-493 6-739 003268 485721 1417 307 94,249 28,934,443 17-521 6-74(5 003257 487138 1413 308 94,864 29,218,112 17-549 6.753 003247 488551 1407 309 95,481 29,503,629 17-578 6-761 003236 489958 1404 310 96,100 29,791,000 17-607 6-768 003226 491362 1398 311 96,721 30,080,231 17-635 6-775 003215 492760 1395 312 97,344 30,371.328 17-663 6-782 003205 494155 1389 313 97,969 30,664,297 17-692 ! 6-781) 003195 495544 1386 314 98.596 30,959,144 ; 17-720 6-797 003185 496930 1381 315 99,225 31,255,875 1 17,748 6-804 003175 498311 1376 316 99,856 31,554,496 17-776 6-811 003165 499687 1372 317 100,489 31,855,013 17-804 6-818 003155 501059 1368 318 101,124 32,157,432 17-832 6-826 003145 502427 1364 319 101,761 32,461,759 17-860 6-833 003135 503791 1359 320 102,400 32,768,000 17-888 6-839 003125 505150 1355 321 103,041 33,076,161 17-916 6-847 003115 506505 1351 322 103.684 33,886,248 17-944 6-854 003106 507856 1347 323 104,329 33,698,267 17-972 6-861 003096 509203 1342 324 104,976 34,012.224 18-000 6-868 003086 510545 1338 325 105,625 34,328,125 18-028 6-875 003077 511883 1335 326 106,276 34,645,976 18-055 6-882 003067 513218 1330 327 106,929 34,965,783 18-083 6-889 003058 514548 1326 328 107,584 35.287,552 18-111 6-896 003049 515874 1322 329 108,241 35,611,289 18-138 6-903 003040 517196 1318 330 108,900 35,937.000 18-166 6-910 003030 518514 1314 331 109,561 36,264,691 18-193 6-917 003021 519828 1310 332 110,224 36,594,368 |18'221 6-924 003012 521138 1306 333 110,889 36,926,037 118-248 6-931 003003 522444 1302 334 111,556 37,259,704 18-276 6-938 002994 523746 1299 335 112,225 37,595,375 18'303 6-945 002985 525045 1294 336 112,896 37.933,056 18-330 6-952 002976 526339 1291 337 113,569 38,272,753 18-357 6-959 002967 527630 1287 338 114,244 38,614,472 18-385 6-966 002959 528917 1283 339 114,921 38,958,219 18-412 6-973 002950 530200 1279 340 115,600 39.304,000 18-439 6-979 002941 531479 1275 341 116,281 39,651,821 18-466 6-986 002933 532754 1272 342 116,964 40,001,688 18-493 6-993 002924 534026 1268 343 117.649 40,353,607 18-520 7-000 002915 535294 1264 344 118,336 40,707,584 18-547 7-007 002907 536558 1261 GENERAL MATHEMATICAL TABLES. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 345 119,025 41,063,625 18-574 7-014 002899 537819 1257 346 119,716 41,421,736 18-601 7-020 002890 539076 1253 347 120,409 41,781,923 18-628 7-027 002882 540329 1250 348 121,104 42.144,192 18-655 7-034 002874 541579 1246 349 121,801 42,508,549 18-681 7-040 002865 542825 1243 350 122,500 42.875,000 18-708 7-047 002857 544068 1239 351 123,201 43,243.551 18-735 7-054 002849 545307 1236 352 123,904 43,614,208 18-762 7-061 002841 546543 1232 353 124,609 43,986,977 18-788 7-067 002833 547775 1228 354 125,31(5 44,361.864 18-815 7-074 002825 549003 1225 355 126,025 44,738,875 18-842 7-081 002817 550228 1222 356 126,736 45,118,016 18-868 7-087 002809 551450 1218 357 ! 127,449 45,499,293 18-894 7-094 002801 552668 1215 358 ! 128,164 45,882,712 18-921 7-101 002793 553883 1211 359 128,881 46,268,279 18-947 7-107 002786 555094 1209 360 129,600 46,656,000 18-974 7-114 002778 556303 1204 361 130,321 47,045,881 19-000 7-120 002770 557507 1201 362 131,044 47,437,928 19-026 7-127 002762 558709 1198 363 131,769 47,832,147 19-052 7-133 002755 559907 1195 364 132.496 48,228,544 19-079 7-140 002747 561101 1192 365 133,225 48,627,125 19-105 7-146 002740 562293 1188 366 133,956 49,027,896 19-131 7-153 002732 563481 1185 367 134,689 49,430,863 19-157 7-159 002725 564666 1182 368 135,424 49,836,032 19-183 7-166 002717 565848 1178 369 136,161 50,243,409 19-209 7-172 002710 567026 1175 370 136,900 50,653,000 19-235 7-179 002703 568202 1172 371 137,641 51,064,811 19-261 7-185 002695 569374 1169 372 138,384 51,478,848 19-287 7-192 002688 570543 1166 373 139,129 51,895,117 19-313 7-198 002681 571709 1163 374 139,876 52,313,624 19-339 7-205 002674 572872 1159 375 140,625 52,734,375 19-365 7-211 002667 574031 1157 376 141,376 53,157,376 19-391 7-218 002660 575188 1154 377 142.129 53,582,633 19-416 7-224 002653 576341 1151 378 142,884 54,010,152 19-442 7-230 002646 577492 1148 379 143,641 54,439,939 19-468 7-237 002639 578639 1145 380 144,400 54.872,000 19-493 7-243 002632 579784 1141 381 145,161 55,306,341 19-519 7-249 002625 580925 1138 382 145,924 55,742,968 19-545 7-256 002618 582063 1135 383 146,689 56,181,887 19-570 7-262 002611 583199 1132 384 147,456 56,623,104 19-596 7-268 ! -002604 584331 1129 385 148,225 57,066,625 19-621 7-275 : -002597 585461 1126 386 148,996 57,512,456 19-647 7-281 -002591 586587 1124 387 149,769 57,960,603 19-672 7-287 -002584 587711 1121 388 150,544 58,411,072 19-698 7-294 -002577 588832 1118 389 151,321 58,863,869 19-723 ! 7-299 -002571 589950 1115 10 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 390 152,100 59,319,000 19-748 7-306 002564 591065 1112 391 152,881 59,776,471 19-774 7-312 002558 592177 1109 392 153,064 60,236,288 19-799 7-319 002551 593286 1106 393 154,449 60,698,457 19-824 7-325 002545 594393 1103 394 155,236 61,162,984 19-849 7-331 002538 595496 1101 395 156,025 61,629,875 19-875 7-337 002532 596597 1098 396 156,816 62,099,136 19-899 7-343 002525 597695 1095 397 157,609 62,570,773 19-925 7-349 002519 598791 1092 398 158,404 63,044,792 19-949 7-356 002513 599883 1090 399 159,201 63,521,199 19-975 7-362 002506 600973 1087 400 160,000 64,000,000 20-000 7-368 002500 602060 10S4 401 160,801 64,481,201 20-025 7-374 002494 603144 1082 402 161,604 64,964,808 20-049 7-380 002488 604226 1079 403 162,409 65,450,827 20-075 7-386 002481 605305 1076 404 163,216 65,939,264 20-099 7-392 002475 606381 1074 405 164,025 66,430.125 20-125 7-399 002469 607455 1071 406 164,836 66,923^16 20-149 7-405 002463 608526 1068 407 165,649 67,419.143 20-174 7-411 002457 609594 1066 408 166,464 67,911,312 20-199 7-417 002451 610660 1063 409 167,281 68,417,929 20-224 7-422 002445 611723 1061 410 168,100 68,921,000 20-248 7-429 002439 612784 1058 411 168,921 69,426,531 20-273 7-434 002433 613842 1055 412 169,744 69,934,528 20-298 7-441 002427 614897 1053 413 170,569 70,444,997 20-322 7-447 002421 615950 1050 414 171,396 70,957,944 20-347 7-453 002415 617000 1048 415 172,225 71,473,375 20-371 7-459 002410 618048 1045 416 173,056 71,991,296 20-396 7-465 002407 619093 1043 417 173.889 72,511,713 20-421 7-471 002398 620136 1040 418 174^724 73,034,632 20-445 7-477 002392 621176 1038 419 175.561 73,560,059 20-469 7-483 002387 622214 1035 420 176,400 74,088,000 20'494 7-489 002381 623249 1033 421 177,241 74,618,461 20-518 7-495 002375 624282 1030 422 178,084 75,151,448 20-543 7-501 002370 625312 1028 423 178,929 75,686,967 20-567 7-507 002364 62G340 1026 424 179,776 76.225.024 20-591 7-513 002358 627366 1023 425 180,625 76,765,625 20-615 7-518 002353 628389 1021 426 181,476 77,308,776 20-639 7-524 002347 629410 1018 427 182,329 77,854.483 20-664 7-530 002342 630428 1016 428 183,184 78,402,752 20-688 7-536 002336 631444 1013 429 184,041 78,953,589 20-712 7-542 002331 632457 1011 430 184,900 79,507,000 20-736 7-548 002326 633468 1009 431 185,761 80,062,991 20-760 7-:>r,4 -002320 634477 1007 432 186,624 80,621,568 20-785 : 7-559 ' -002315 635484 1004 433 187,489 81,182,737 20-809 7-565 -002309 636488 1002 434 188,356 81,746,504 20-833 7-571 -002304 637490 999 GENERAL MATHEMATICAL TABLES. 11 No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 435 189,225 82,312,875 20-857 7*577 002299 638489 997 436 190,096 82,881,856 20-881 7-583 002294 639486 995 437 H>0,lh59 83,453,453 20-904 7-588 002288 640481 993 438 191,844 84,027. (572 20-928 7-594 002283 641474 991 439 192,721 84,604,519 20-952 7-600 002278 642465 988 440 193,600 85,184,000 20-976 7-606 002273 643453 986 441 194,481 85,76(5.121 21-000 7-612 002268 644439 983 442 195,364 8(>,3r>o,3SS 21-024 7-617 002262 645422 981 443 196,249 86,938,307 21-047 7-623 002257 646404 979 444 197,136 87,528,384 21-071 7-629 002252 647383 977 445 198,025 88,121,125 21-095 7-635 002247 648360 975 446 198,916 88,71(5. 53(5 21-119 7-640 002242 649335 973 447 199,809 89,314,623 21-142 7-646 002237 650308 970 448 200,704 89,915,392 21-166 7-652 002232 651278 968 449 201,601 90,518,849 21-189 7-657 002227 652246 967 450 202,500 91,125,000 21-213 7-663 002222 653213 964 451 203,401 91,733,851 21-237 7-669 002217 654177 962 452 204,304 92,345,408 21-260 7-674 002212 655138 960 453 205,209 92,959,677 21-284 7-680 002208 656098 958 454 206,106 93,576,664 21-307 7-686 002203 657056 956 455 207,025 94,196.375 21-331 7-691 002198 658011 954 456 207.936 94,818,816 21-354 7-697 002193 658965 951 157 208,849 95,443^993 21-377 7-703 002188 659916 949 458 209,764 96,071,912 21-401 7-708 002183 660865 947 159 210,681 96,702,579 21-424 7-714 002179 661813 945 460 211,600 97,336.000 21-447 7-719 002174 662758 943 461 212,521 97,972,181 21-471 7-725 002169 663701 941 462 213,444 98,611,128 21-494 7-731 002165 664642 939 463 214,3(59 99,252,847 21-517 7-736 002160 665581 937 464 215,296 99,897,345 21-541 7-742 002155 666518 935 465 216.225 100,544,625 21-564 7-747 002151 667453 933 466 217,156 101,194,696 21-587 7-753 002146 668386 931 467 218,089 101,847.563 21-610 7-758 002141 669317 92!) 468 219,024 102,503,232 21-633 7-764 002137 670246 927 469 219,961 103,161,709 21-656 7-769 002132 671173 025 470 220,900 103,823,000 21-679 7-775 002128 672098 923 471 221,841 104,487,111 21-702 7-780 002123 673021 921 472 222,784 105.154,048 21-725 7-786 002119 673942 919 473 223,729 105^823,817 21-749 7-791 002114 674861 917 474 224,676 106,496,424 21-771 7-797 002110 675778 915 475 225,625 107,171,875 21-794 7-802 002105 676694 913 476 226,576 107,850,176 21-817 7-808 002101 677607 911 477 227,529 108,531,333 21-840 7-813 002096 678518 910 478 228,484 109,215,352 21-863 7-819 002092 679428 908 479 229,441 109,902,239 21-886 7-824 002088 680336 905 12 GAS ENGINEERS POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 480 230,400 110,592,000 21-909 7-830 002083 681241 904 481 231,361 111,284,641 21-932 7-835 002079 682145 902 482 232,324 111,980,168 21-954 7-840 002075 683047 900 483 233,289 112,678,587 21-977 7-846 002070 683947 898 484 234,256 113,379,904 22-000 7-851 002066 684845 89(5 485 235,225 114,084,125 22-023 7-857 002062 685742 894 486 236,196 114,791,256 22-045 7-862 002058 686636 893 487 237,169 115,501,303 22-069 7-868 002053 687529 891 488 238,144 116,214,272 22-091 7-873 002049 688420 889 489 239,121 116,936,169 22-113 7-878 002045 689309 887 490 240,100 117,649,000 22-136 7-884 002041 690196 885 491 241,081 118,370,771 22-158 7-889 002037 691081 884 492 242,064 119,095,488 22-181 7-894 002033 691965 882 493 243,049 119,823,157 22-204 7-899 002028 692847 880 494 244,036 120,553,784 22-226 7-905 002024 693727 878 495 245,025 121,287,375 22-248 7-910 002020 694605 876 496 246,016 122,023,936 22-271 7-915 002016 695482 874 497 247,009 122,763,473 22-293 7-921 002012 696356 873 498 248,004 123,505,992 22-316 7-926 002008 697229 871 499 249,001 124,251,499 22-338 7-932 002004 698101 869 500 250,000 125,000,000 22-361 7-937 002000 698970 868 501 251,001 125,751,501 22-383 7-942 001996 699838 866 502 252,004 126,506,008 22-405 7-947 001992 700704 864 503 253,009 127,263,527 22-428 7-953 001988 701568 862 504 254,016 128,024,864 22-449 7-958 001984 702431 860 505 255,025 128,787,625 22-472 7-963 001980 703291 859 506 256,036 129,554,216 22-494 7-969 001976 704151 857 507 257,049 130,323,843 22-517 7-974 001972 705008 856 508 258,064 131,096,512 22-539 7-979 001969 705864 854 509 259,081 131,872,229 22-561 7-984 001965 706718 852 510 260,100 132,651,000 22-583 7-989 001961 707570 851 511 261,121 133,432,831 22-605 7-995 001957 708421 849 512 262,144 134,217,728 22-627 8-000 001953 709270 847 513 263,169 135,005,697 22-649 8-005 001949 710117 846 514 264,196 135,796,744 22-671 8-010 001946 710963 844 515 265,225 136,590,875 22-694 8-016 001942 711807 843 516 266,256 137,388,096 22-716 8-021 001938 712650 841 517 267,289 138,188,413 22-738 8-026 001934 713491 839 518 268,324 138,991,832 22-759 8-031 001931 714330 837 519 269,361 139,798,359 22-782 8-036 001927 715167 836 520 270,400 140,608,000 22-803 8-041 001923 716003 835 521 271,441 141,420,761 22-825 8-047 001919 716838 833 522 272,484 142,236,648 22-847 8-052 001916 717671 831 523 273,529 143,055,667 22-869 8-057 001912 718502 829 524 274,576 143,877,824 22-891 8-062 001908 719331 828 GENERAL MATHEMATICAL TABLES. 13 No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 525 275,625 144,703,125 22-913 8-067 001905 720159 827 526 276,676 145,531,576 22-935 8-072 001901 720986 825 527 277,729 146,363,183 22-956 8-077 001898 721811 823 528 278.784 147,197,952 22-978 8-082 001894 722634 822 529 279,841 148,035,889 23-000 8-087 001890 723456 820 530 280.900 148,877,000 23-022 8-093 001887 724276 819 531 281,961 149,721,291 23-043 8-098 001883 725095 817 532 283,024 150,568,768 23-065 8-103 001880 725912 815 533 284,089 151,419,437 23-087 8-108 001876 726727 814 534 285,156 152,273,304 23-108 8-113 001873 727541 813 535 286,225 153,130,375 23-130 8-118 001869 728354 811 536 287,296 153,990,656 23-152 8-123 001866 729165 809 537 288,369 154,854,153 23-173 8-128 001862 729974 808 538 289,444 155,720,872 23-195 8-133 001859 730782 807 539 290,521 156,590,819 23-216 8-138 001855 731589 805 540 291,600 157,464,000 23-238 8-143 001852 732394 803 541 292,681 158,340,421 23-259 8-148 001848 733197 802 542 293.764 159.220,088 23-281 8-153 001845 733999 801 543 294,849 160,103,007 23-302 8-158 001842 734800 799 544 295,936 160,989,184 23-324 8-163 001838 735599 798 545 297,025 161,878,625 23-345 8-168 001835 736397 796 546 298,116 162,771,336 23-367 8-173 001832 737193 794 547 299,209 163,667,323 23-388 8-178 001828 737987 793 548 300,304 164,566,592 23-409 8-183 001825 738781 792 549 301,401 165,469,149 23-431 8-188 001821 739572 791 550 302,500 166,375,000 23-452 8-193 001818 740363 789 551 3U3,601 167,281,151 23-473 8-198 001815 741152 787 552 304,704 168,196,608 23-495 8-203 001812 741939 786 553 305,809 169,112,377 23-516 8-208 001808 742725 785 554 306,916 170,031,464 23-537 8-213 001805 743510 783 555 308,025 170,953,875 23-558 8-218 001802 744293 782 556 309,136 171,879,616 23-579 8-223 001799 745075 780 557 310,249 172,808,693 23-601 8-228 001795 745855 779 558 311,364 173,741,112 23-622 8 233 001792 746634 778 559 312,481 174,676,879 23-643 8-238 001789 747412 776 560 313,600 175,616,000 23-664 8-242 001786 748188 775 561 314,721 176,558,481 23-685 8-247 001783 748963 773 562 315,844 177,504,328 23-706 8-252 001779 749736 772 563 316,969 178,453,547 23-728 8-257 001776 750508 771 564 318,096 179,406,144 23-749 8-262 001773 751279 769 565 319,225 180,362,125 23-769 8-267 001770 752048 768 566 320,356 181,321,496 23 791 8'272 001767 752816 767 567 321,489 182,284,263 23-812 8-277 001764 753583 765 568 322,624 183,250,432 23'833 8-282 001761 754348 764 569 323,761 184,220,009 23-854 8-286 001757 755112 763 14 GAS ENGINEER S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 570 324,900 185,193,000 23-875 8-291 001754 755875 761 571 326,041 186,169,411 23-896 8296 001751 756636 7GO 572 327,184 187,149,248 23-916 8-301 001748 757396 759 573 328,329 188.132,517 23-937 8-306 001745 758153 757 574 329,476 189,119,224 23-958 8-311 001742 758912 756 575 330,625 190,109,375 23-979 8-315 001739 759668 754 576 331,776 191.102,976 24-000 8-320 001736 760422 753 577 332,929 192,100,033 24-021 8-325 001733 761176 752 578 334,084 193,100,552 24-042 8-330 001730 761928 751 579 335,241 194,104,539 24-062 8-335 001727 762679 749 580 336,400 195,112,000 24-083 8-339 001724 763228 748 581 337,561 196,122,941 24-104 8-344 001721 764176 747 582 338,724 197,137,368 24-125 8-349 001718 764923 74(5 583 339,889 198,155,287 24-145 S-354 001715 765669 744 584 341,056 199,176,704 24-166 8-359 001712 766413 743 585 342,225 200,201,625 24-187 8-363 001709 767156 742 586 343,396 201,230,056 24-207 8-368 001706 767898 740 587 344,569 202,262,003 24-228 8-373 001704 768638 739 588 345,744 203,297,472 24-249 8-378 001701 769377 738 589 346,921 204,336,469 24-269 8-382 001698 770115 737 590 348,100 205.379,000 24-289 8-387 001695 770852 735 591 349,281 206,425,071 24-310 8-392 001692 771587 734 592 350,464 207,474,688 24-331 8-397 001689 772322 733 593 351,649 208,527,857 24-351 8-401 001686 773055 731 594 352,836 209,584,584 24-372 8-406 001684 773786 730 595 354,025 210,644,875 24-393 8-411 001681 774517 729 596 355,216 211,708,736 24-413 8-415 001678 775246 728 597 356,409 212,776,173 24-433 8-420 001675 775974 727 598 357,604 213,847,192 24-454 8-425 001672 776701 726 599 358,801 214,921,799 24-474 8-429 001669 777427 724 600 360.000 216,000,000 24-495 8-434 001667 778151 723 601 361,201 217,081,801 24-.-) 15 8-439 001664 778874 722 602 362,404 218,167,208 24-536 8-444 001661 779596 721 603 363,609 219,256,227 24-556 8-448 001658 780317 720 604 364,816 220,348,864 24-576 8-453 001656 781037 719 605 366,025 221,445,125 24-597 8-458 001653 781755 718 606 367,236 222,545,016 24-617 8-462 001650 782473 716 607 368,449 223,648,543 24-637 8-467 001647 783189 715 608 369,664 224,755,712 24-658 8-472 001645 783904 714 609 370,881 225.866,529 24-678 8-476 001642 784617 713 610 372,100 226,981,000 24-698 8-481 001639 785330 711 611 373,321 228,099,131 24-718 8-485 001637 786041 ,710 612 374,544 229,220,928 24-739 8-490 001634 786751 709 613 375,769 230,346,397 24-758 8-495 001631 787460 708 614 376,996 231,475,544 24-779 8-499 001629 788168 707 GENERAL MATHEMATICAL TABLES. 15 No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 615 378,225 232,608,375 24-799 8-504 001626 788875 706 616 379,456 233,744,896 24-819 8-509 001623 789581 704 617 380,689 234,885,113 24-839 8-513 001621 790285 703 ' 618 381,924 236.029,032 24-859 8-518 001618 790988 702 619 383,161 237,176,659 24-879 8-522 001616 791691 701 620 384,400 238,628,000 24-899 8-527 001613 792392 700 621 385,641 239,483,061 24-919 8-532 001610 793092 699 622 386,884 240,641,348 24-939 8-536 001608 793790 698 623 388.129 241,804,367 24-959 ! 8-541 001605 794488 697 624 389^376 242,970,624 24-980 8-545 001603 795185 695 625 390,625 244,140,625 25-000 1 8-549 001600 795880 694 626 391,876 245.314,376 25-019 8-554 001597 796574 693 627 393,129 246,491,883 25-040 8-559 001595 797268 692 628 ; 394,384 247,673,152 25-059 8-563 001592 797960 691 629 395,641 248,858,189 25-079 8-568 001590 798651 690 630 396,900 250,047,000 25-099 8-573 001587 799341 689 631 398,161 251,239,591 25-119 8-577 001585 800029 688 632 399,424 252,435,968 25-139 8-582 001582 800717 687 633 400,689 253,636,137 25-159 8-586 001580 801404 685 634 401,956 254,840,104 25-179 8-591 001577 802089 684 635 403,225 256.047,875 25-199 8-595 001575 802774 683 636 404,496 257,259,456 25-219 8-599 001572 803457 682 637 405,769 258.474,853 25-239 8-604 001570 804139 681 638 407,044 259,694,072 25-259 8-609 001567 804821 680 639 408,321 260,917,119 25-278 8-613 001565 805501 679 640 409,600 262,114,COO 25-298 8-618 001563 806180 678 641 410,881 263,374.721 2V318 8-622 001560 806858 677 642 412.164 264,609,28 25-338 8-627 001558 807535 676 643 ' 413,449 265,847,707 25-357 8-631 001555 808211 675 644 414,736 267,089,984 25-377 8-636 001553 808886 674 645 j 416,025 | 268,836,125 25-397 8-640 001550 809560 673 646 ! 417,316 j 269,586,136 25-416 8-644 001548 810233 672 647 i 418,609 270,840,023 25-436 8-649 001546 810904 671 648 i 419,904 272,097,792 25-456 8-653 001543 811575 670 649 421,201 273,359,449 25-475 8-658 001541 812245 669 650 422,500 274,625,000 25-495 8-662 001538 812913 668 651 423,801 275,894,451 25*515 8-667 001536 813581 667 652 425,104 277,167,808 25-534 8-671 001534 814248 666 653 426,409 278,445,077 25-554 8-676 001531 814913 665 654 427,716 279,726.264 25-573 8-680 001529 815578 664 655 429,025 281,0 1U75 25-593 8-684 001527 816241 663 656 430,336 282,800,416 25-612 8-689 001524 816904 662 657 431,649 283,593,393 25-632 8-693 001522 817565 661 658 432,964 284,890,312 25-651 8-698 001520 818226 660 659 434.281 286,191,179 25-671 8-702 001517 818885 659 16 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 660 435,600 287,496,000 25-690 8-706 001515 819544 658 661 436,921 288,804.781 25-710 8-711 001513 820201 657 662 438,244 290,117,528 25-720 8-715 001511 820858 656 663 439,569 291,434,247 25-749 8-719 001508 821514 654 664 440,896 292,754,1)44 25*768 8-724 001506 822168 653 665 442,225 294,079,625 25-787 8-728 001504 822822 652 666 443,556 295,408,296 25-807 8-733 001502 823474 651 667 444,889 296,740,963 25-826 8-737 001499 824126 650 668 446,224 298,077,632 25-846 8-742 001497 824776 650 669 447,561 299,418,309 25-865 8-746 001495 825426 649 670 448,900 300,763,000 25-884 8-750 001493 826075 648 671 450,241 302,111,711 25-904 8-753 001490 826723 647 672 451,584 303,464,448 25-923 8-759 001488 827369 646 673 452,929 304,821,217 25-942 8-763 001486 828015 645 674 454,276 306,182,024 25-961 8-768 001484 828660 644 675 455,625 307,546,875 25-981 8-772 001481 829304 643 676 456.976 308,915,776 26-000 8-776 001479 829947 642 677 458,329 310,288,733 26-019 8-781 001477 830589 641 678 459,684 311,665,752 26-038 8-785 001475 831230 640 679 461,041 313,046,839 26-058 8-789 001473 831870 639 680 462,400 314,432,000 26-077 8-794 001471 832509 638 681 463,761 315,821,241 26-096 8'798 001468 833147 637 682 465,124 317,214,568 26-115 8-802 001466 833784 637 683 466,489 318,611,987 26-134 8-807 001464 834421 636 684 467,856 320,013,504 26-153 8-811 001462 835056 635 685 469,225 321,419,125 26-172 8-815 001460 835691 634 686 470,596 322,828,856 26-192 8-819 001458 836324 633 687 471,969 324,242,703 26-211 8-824 001456 836957 632 688 473,344 325,660,672 26-229 8-8: J 8 001453 837588 631 689 474,721 327,082,769 26-249 8-832 001451 838219 630 690 476,100 328,509,000 26-268 8-836 001449 838849 629 691 477,481 329,939,371 26-287 8-841 001447 839478 628 692 478,864 331,373,888 26-306 8-845 001445 840106 627 693 480,249 332,812,557 26-325 8-849 001443 840733 626 694 481,636 334,255,384 26-344 8-853 001441 841359 625 695 483,025 335,702,375 26-363 8-858 001439 841985 624 696 484,416 337,153,536 26-382 8-862 001437 842609 623 697 485,809 338,608,873 26-401 8-866 001435 843233 622 698 487,204 340,068,392 26-419 8-870 001433 843855 622 699 488,601 341,532,099 26-439 8-875 001431 844477 621 700 490,000 343,000,000 26-457 8-879 001429 845098 620 701 491.401 344,472,101 26-476 8-883 001427 845718 619 702 492^04 345,948,088 26-495 8-887 001425 846337 618 703 494,209 347,528,927 26-514 8-892 001422 846955 617 704 495,616 348,913,664 26-533 8-896 001420 847573 616 GENERAL MATHEMATICAL TABLES. 17 No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 705 497,025 350,402,625 26-552 8-900 001418 848189 615 706 498,430 351,895,816 26-571 8-904 001416 848805 614 707 499,849 353,393,243 26-589 8-908 001414 849419 614 708 501,264 354,894,912 26-608 8-913 001412 850033 613 709 502,681 356,400,829 26-627 8-917 001410 850646 612 710 504,100 357,911,000 26-644 8-921 001408 851258 611 711 505,521 359,425,431 26-664 8-925 001406 851870 610 712 506,944 360,944.128 26-683 8-929 001404 852480 610 713 508,369 362,467,097 26-702 8-934 001403 853090 609 714 509.796 363,994.344 26-721 8-938 001401 853698 608 715 511,225 365,525.875 26-739 8-942 001399 854306 607 716 512,656 367,061,696 26-758 8-946 001397 854913 606 717 514,089 368,601,813 26-777 8-950 001395 855519 605 718 515,524 370.146.232 26-795 8-954 001393 856124 604 719 516,961 371^694,959 26-814 8-959 001391 856729 603 720 518,400 373,248,000 26-833 8-963 001389 857332 603 721 519.841 374,805,361 26-851 8-967 001387 857935 602 722 521,284 376,367,048 26-870 8-971 001385 858537 601 723 522,729 377,933,007 26-889 8-975 001383 859138 600 724 524,176 379,503,424 26-907 8-979 001381 859739 599 725 525.625 381,078,125 26-926 8-983 001379 860338 598 726 527,076 382,657,176 26-944 8-988 001377 860937 597 727 528,529 384,240,583 26-963 8-992 001376 861534 597 728 529,984 385,828,352 26-991 8-996 001374 862131 596 729 531,441 387,420,489 27-000 9-000 001372 862728 595 730 532,900 389,017,000 27-018 9-004 001370 863323 594 731 534,361 390,617,891 27-037 9-008 001368 863917 594 732 535,824 392,223,168 27-055 9-012 001366 864511 593 733 537,289 393,832,837 27-074 9-016 001364 865104 592 734 538,756 395,446,904 27-092 9-020 001362 865696 591 735 540,225 397,065,375 27-111 9-023 001361 866287 590 736 541,696 398,688,256 27-129 9-029 001359 866878 589 737 543,169 400,315,553 27-148 9-033 001357 867467 589 738 544,644 401,947,272 27-166 9-037 001355 868056 588 739 546,121 403,583,419 27-184 9-041 001353 868644 587 740 547,600 405,224,000 27-203 9-045 001351 869232 586 741 549,081 406,869,021 27-221 9-049 001350 869818 586 742 550,564 408,518,488 27-239 9-053 001348 870404 585 743 552,049 410,172,407 27-258 9-057 001346 ,870989 584 744 553,536 411,830,784 27-276 9-061 001344 871573 583 745 555,025 j 413,493,625 27-295 9-065 001342 872156 583 746 556,516 415.160.936 27-313 9-069 001340 872739 582 747 558,009 416,832,723 27-331 9-073 001339 873321 581 748 559,504 418,508,992 27-349 9-077 001337 873902 580 749 |:>ei,ooi 420,189,749 27-368 ! 9-081 001335 874482 579 G.E. 18 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 750 562,500 421,875,000 27-386 9-086 001333 875061 579 751 564,001 423,564,751 27-404 9-089 001332 875640 578 752 565,504 424,525,900 27-423 9-094 001330 876218 577 753 567,009 426,957,777 27-441 9-098 001328 876795 576 754 568,516 428,661,064 27-459 9-102 001326 877371 576 755 570,025 430,368,875 27-477 9-106 001325 877947 575 756 571,536 432,081,216 27-495 9-109 001323 878522 574 757 573,049 433,798,093 27-514 9-114 001321 879096 573 758 574,564 435,519,512 27-532 9-118 001319 879669 573 759 576,081 437,245,479 27-549 9-122 001318 880242 572 760 577,600 438,976,000 27-568 9-126 001316 880814 571 761 579,121 440,711,081 27-586 9-129 00^314 881385 570 762 580,644 442,450,728 27-604 9-134 001312 881955 570 763 582,169 444,194,947 27-622 9-138 001311 882525 569 764 583,696 445,943,744 27-640 9-142 001309 883093 568 765 585,225 447,697,125 27-659 9-146 001307 883661 567 766 586,756 449,455,096 27-677 9-149 001305 884229 566 767 588,289 451,217,663 27-695 9-154 001304 884795 566 768 589,824 452,984,832 27-713 9-158 001302 885361 565 769 591,361 454,756,609 27-731 9-162 001300 885926 565 770 592,900 456.533,000 27-749 9-166 001299 886491 564 771 594,441 458,314,011 27-767 9-169 001297 887054 563 772 595,984 460,099,648 27-785 9-173 001295 887617 562 773 597,529 461,889,917 27-803 9-177 001294 888179 562 774 599,076 463,684,824 27-821 9-181 001292 888741 561 775 600,625 465,484,375 27-839 9-185 001290 889302 560 776 602,176 467,288,576 27-857 9-189 001289 889862 559 777 603,729 469,097,433 27-875 9-193 001287 890421 559 778 605,284 470,910,952 27-893 9-197 001285 890980 558 779 606,841 472,729,139 27-910 9-201 001284 891537 558 780 608,400 474,552,000 27-928 9-205 001282 892095 556 781 609,961 476,379,541 27-946 9-209 001280 892651 556 782 611,524 478,211,768 27-964 9-213 001279 893207 555 783 613,089 480,048,687 27-982 9-217 001277 893762 554 784 614,656 481,890,304 28-000 9-221 001276 894316 554 785 616,225 483,736,625 28-017 9-225 001274 894870 553 786 617,796 485,587,656 28-036 9-229 001272 895423 552 787 619,369 487,443,403 28-053 9-233 001271 895975 551 788 620,944 489,303,872 28-071 9-237 001269 896526 551 789 622,521 491,169,069 28-089 9-240 001267 897077 550 790 624,100 493,039,000 28-107 9-244 001266 897627 549 791 625,681 494,913,671 28-125 9-248 001264 898176 549 792 627,624 496,793,088 28-142 9-252 001263 898725 548 793 628,849 498,677,257 28-160 9-256 001261 899273 547 794 630,436 500,566,184 28-178 9-260 001259 899821 546 GENERAL MATHEMATICAL TABLES. 19 No. Square. ~ . , Square Cube - Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 795 632,025 502,459,875 28-196 9-264 001258 900367 546 796 633,616 504,358,336 28-213 9-268 001256 900913 545 797 635,209 506,261,573 28-231 9-271 001255 901458 545 798 636,804 508,169,592 28-249 9-275 001253 902003 544 799 638,401 510,082,399 28-266 9-279 001251 902547 543 800 640,000 512,000,000 28-284 9-283 001250 903090 542 801 641,601 513,922,401 28-302 9-287 001248 903633 541 802 643,204 515,849,608 28-319 9-291 001247 904174 541 803 644,809 517,781,627 28-337 9-295 001245 904716 540 804 646,416 519,718,464 28'355 9-299 001244 905256 540 805 648,025 521,660,125 28-372 9-302 001242 905796 539 806 649,636 523,606,616 28-390 9-306 001241 906335 538 807 651,249 525,557,943 28-408 9-310 001239 906874 537 808 652,864 527,514,112 28-425 9-314 001238 907411 537 809 654,481 529,475,129 28-443 9-318 001236 907949 536 810 656,100 531,441,000 28-460 9-321 001235 908485 536 811 657,721 533,411,731 28-478 9-325 001233 909021 535 812 659,344 535,387,328 28-496 9-329 001232 909556 535 813 660,969 537,366,797 28-513 9-333 001230 910091 534 814 662,596 539,353,144 28-531 9-337 001229 910624 533 815 664,225 541,343,375 28-548 9-341 001227 911158 533 816 665,856 543,338,496 28-566 9-345 001225 911690 533 817 667,489 545,338,513 28-583 9-348 001224 912220 532 818 669,124 547,343,432 28-601 9-352 001222 912753 531 819 670,761 549,353,259 28-618 9-356 001221 913284 530 820 672,400 551,368,000 28-636 9-360 001220 913814 529 821 674,041 553,387,661 28-653 9-364 001218 914343 529 822 675,684 555,412,248 28-670 9-367 001217 914872 528 823 677,329 557,441,767 28-688 9-371 001215 915400 527 824 678,976 559,476,224 28-705 9-375 001214 915927 527 825 680,625 561,515,625 28-723 9-379 001212 916454 526 826 682,276 563,559,976 28-740 9-383 001211 916980 526 827 683,929 565,609,283 28-758 9-386 001209 917506 525 828 685,584 567,663,552 28-775 9-390 001208 918030 524 829 687,241 569,722,789 28-792 9-394 -001206 918555 523 830 688,900 571,787,000 28-810 9-398 001205 919078 523 831 690,561 573,856,191 28-827 9-401 001203 919601 522 832 692,224 575,930,368 28-844 9-405 001202 920123 522 833 693,889 578,009,537 28-862 9-409 001200 920645 521 834 695,556 580,093,704 28-879 9-413 001199 921166 520 835 697.225 582,182,875 28-896 9-417 001198 921686 520 836 698,896 584,277,056 28-914 9-420 001196 922206 519 837 700,569 586,376,253 28-931 9-424 001195 922725 519 838 702,244 588,480,472 28-948 9-428 001193 923244 518 839 703,921 590,589,719 28-965 9-432 001192 923762 517 20 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Cube Root. Root. Recip- rocal. Loga- rithm. Differ- ence. 840 705.600 592,704,000 28-983 i 9-435 001190 924279 517 841 707.281 594,823.321 29-000 9-439 001189 924796 516 842 708,964 596,947,688 29-017 9-443 001188 925312 516 843 710,649 599,077,107 29-034 9-447 001186 1)25828 515 844 712,336 601,211,584 29-052 9-450 001185 D263-J2 r.ii 845 714,025 603,351,125 29-069 9-454 001183 926857 513 846 715,716 605,495,736 29-086 ! 9-458 001182 927370 513 847 717,409 607,645,423 29-103 9-461 001181 927883 513 848 719,104 609,800.192 29-120 9-465 001179 928396 512 849 720,801 611,960,049 29-138 9-469 001178 928908 511 850 722,500 614,125,000 29-155 9-473 001176 929419 511 851 724.201 616.295.051 29-172 9-476 001175 929930 510 852 725,04 618.470,208 29-189 9-480 001174 930440 509 853 727,609 620,650,477 29-206 9-483 001172 930949 509 854 729,316 622,835,864 29-223 9-487 001171 931458 508 855 731,025 625.026,375 29-240 9-491 001170 931966 508 856 732,736 627^222,016 29-257 9-495 001168 932474 507 857 734,419 629,422.793 29-274 9-499 001167 932981 506 858 736,164 631,628,712 29-292 9-502 001166 933487 506 859 737,881 633,839,779 29-309 9-506 001164 933993 505 860 739,600 636,056,000 29-326 9-509 001163 934498 505 861 741.321 638,277,381 29-343 9-513 001161 935003 504 862 743,044 640.503^928 29-360 9-517 001160 935507 504 863 744,769 642,735,647 29-377 9-520 001159 936011 503 864 746,496 644,972,544 29-394 9-524 001157 93651 4 502 865 748.225 647,214,625 29-411 9-528 001156 937016 502 866 749,956 649,461,896 29-428 9-532 001155 937518 501 867 751,689 651,714,363 29-445 9-535 001153 938019 501 868 753,42 N 4 653,972,032 29-462 9-539 001152 938520 500 869 755,161 656,234,909 29-479 9-543 001151 939020 499 870 756,900 658,503,000 29-496 9-546 001149 939519 499 871 758,641 660,776,311 29-513 9-550 001148 940018 498 872 760,384 663,054,848 29-529 9-554 001147 940516 498 873 762,129 665,388,617 29-546 9-557 001145 941014 497 874 763,876 667,627,624 29-563 9-561 001144 941511 497 875 765,625 669,921,875 29-580 9-565 001143 942008 496 876 767,376 672,221,376 29-597 9-568 001142 942504 496 877 769,129 674,526,133 29-614 9-572 001140 943000 495 878 770,884 676,836,152 29-631 9-575 001139 943495 494 879 772,641 679,151,439 29-648 9-579 001138 943989 494 880 774,400 681,472,000 29-0(55 9-583 001136 944483 493 881 776,161 683,797,841 29-682 9-586 -001135 944976 493 882 777.924 686,128,96 29-698 9-590 -001134 945469 492 883 779,689 688,465,387 29-715 9-594 -001133 945961 491 884 781,456 690,807,104 29-732 9-597 -001131 946452 491 GENERAL MATHEMATICAL TABLES. 21 No. Square. Cube. Square Boot. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 885 783,225 693,154,125 29-749 9-601 001130 946943 490 886 ! 784,996 695,506,456 29-766 9-604 001129 947434 490 887 786,769 697,864,103 29-782 9-608 001127 947924 489 888 788,544 700,227,072 29-799 9-612 001126 948413 489 889 790,321 702,595,369 29-816 9-615 001125 948902 488 890 792,100 704,969,000 29-833 9-619 001124 949390 488 891 793,881 707,347,971 29-850 9-623 001122 949878 487 892 795,664 709,732,288 29-866 9-626 001121 950365 486 893 797,449 712,121,957 29-883 9-630 001120 950851 486 894 799,236 714,516,984 29-900 9-633 001119 951338 485 895 801,025 716,917,375 29-916 9-637 001118 951823 485 896 ; 802,816 719,323,136 29-933 9-640 001116 952308 484 897 | 804,609 721,734,273 29-950 9-644 001115 952792 484 898 806,404 724,150,792 29-967 9-648 001114 953276 484 cqn OOv/ 808,201 726,572,699 29-983 9-651 001112 953760 483 900 810,000 729,000,000 30-000 9-655 001111 954243 482 901 811,801 731,432,701 30-017 9-658 001110 954725 482 902 813,604 733,870,808 30-033 9-662 001109 955207 481 903 815,409 736,314,327 30-050 9-666 001107 955688 480 904 817,216 738,763,264 30-066 9-669 001106 956168 480 905 819,025 741,217,625 30-083 9-673 001105 956649 479 906 820,836 743,677,416 30-100 9-676 001104 957128 479 907 822,649 746,142.643 30-116 9-680 001103 957604 478 908 824,464 748,613^312 30-133 9-683 001101 958086 478 909 826,281 751,089,429 30-150 9-687 001100 958564 477 910 828,100 753,571,000 30-163 9-690 001099 959041 477 911 829,121 756.058,031 30-183 9-694 001098 959518 477 912 831,744 758,550,528 30-199 9-698 001096 959995 476 913 833,569 761,048,497 30-216 9-701 001095 960471 475 914 835,396 763,551,944 30-232 9-705 001094 960946 475 915 837,225 766,060,875 30-249 9-708 001093 961421 474 916 839,056 768,575,296 30-265 9-712 001092 961895 474 917 840,889 771,095,213 30-282 9-715 001091 962363 474 918 842,724 773,620,632 30-298 9-718 001089 962843 473 919 844,561 776,151,559 30-315 9-722 001088 963316 473 920 846,400 778,688,000 30-331 9-726 001087 963788 472 921 848,241 781,229,961 30-348 9-729 001086 964260 471 922 850,084 783,777,448 30-364 9-733 001085 964731 471 923 851,929 786,330,467 30-381 9-736 001083 965202 470 924 853,776 788,889,024 30-397 9-740 001082 965672 470 925 855,625 791.453,125 30-414 9-743 001081 966142 469 926 857,476 794,022,776 30-430 9-747 001080 966611 469 927 859,329 796,597,983 30-447 9-750 001079 967080 468 928 861,184 799,178.752 30-463 9-754 001078 967548 468 929 863,041 801.765,089 30-479 ! 9-757 001076 968016 467 GAS ENGINEER'S POCKET-BOOK. No. Square. Cube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 930 864,900 804,357,000 30-496 9-761 001075 968483 467 931 866,761 806,954.491 30-512 9-764 001074 968950 466 932 868,624 809,557,568 30-529 9-768 C01073 969416 466 933 870,489 812,166.237 30-545 9-771 001072 969882 465 934 872,356 814,780.504 30-561 9-775 001071 970347 465 935 874,225 817,400,375 30-578 9-778 001070 970812 464 936 876,096 820,025,856 30-594 9-783 001068 971276 464 937 877,969 822,656,953 30-610 9-785 001067 971740 463 938 879,844 825,293,672 30-627 9-789 001066 972203 463 939 881,721 827,936,019 30-643 9-792 001065 972666 462 940 883,600 830,584.000 30-659 9-796 001064 973128 462 941 885,481 883,237,621 30-676 9-799 001063 973590 461 942 887,364 835,896.888 30-692 9-803 001062 974051 461 943 889,249 838,561,807 30-708 9-806 001060 974512 460 944 891,136 841.232,284 30-724 9-810 001059 974972 460 945 893,025 843,908,625 30-741 9-813 001058 975432 459 946 894,916 846,590,536 30-757 9-817 001057 975891 459 947 896.809 849.278,123 30-773 9-820 001056 976350 458 948 898,704 851,971,392 30-790 9-823 001055 976808 458 949 900,601 864,670,349 30-806 9-827 001054 977266 457 950 902,500 857,375,000 30-822 9-830 001053 977724 457 951 904,401 860,085,351 30-838 9-834 001052 978181 456 952 906,304 862,801.408 30-854 9-837 001050 978637 456 953 908,209 865,523,177 30-871 9-841 001049 979093 455 954 910,116 868,250,664 30-887 9-844 001048 979548 455 955 912,025 870,983.875 30-903 9-848 001047 980003 455 956 913,936 873,722,816 30-919 9-851 001046 980458 454 957 915,849 876,467,493 30-935 9-854 001045 980912 454 958 917,764 879,217,912 30-951 9-858 001044 981366 453 959 919,681 881,974,079 30-968 9-861 001043 981819 452 960 921,600 884,736,000 30-984 9-865 001042 982271 452 961 923,521 887,503,681 31-000 9-868 001041 982723 452 962 925,444 890,277,128 31-016 9-872 001040 983175 451 963 927,369 893,056,347 31-032 9-875 001038 983626 451 964 929,296 895,841,344 31-048 9-878 001037 984077 450 965 931,225 898,632,125 31-064 9-881 001036 984527 450 966 933,156 901,428,696 31-080 9-885 001035 984977 449 967 935,089 904,231,063 31-097 9-889 001034 985426 449 968 937,024 907,039,232 31-113 9-892 001033 985875 449 969 938,961 909,853,209 31-129 9-895 001032 986324 448 970 940,900 912,673,000 31-145 9-899 001031 986772 447 971 942,841 915,498,611 31-161 9-902 001030 987219 ! 447 972 944,784 918,330,048 31-177 9-906 001029 987666 447 973 946,729 921,167,317 31-193 9-909 001028 988113 ! 446 974 948,676 924,010,424 31-209 9-912 001027 988559 446 GENERAL MATHEMATICAL TABLES. 23 No. Square. ICube. Square Root. Cube Root. Recip- rocal. Loga- rithm. Differ- ence. 975 950,625 926,859,375 31-225 9-916 -001026 989005 445 976; 952,576 929,714,176 31-241 9-919 -001025 989450 445 977 954,529 932,574,833 31-257 9-923 -001024 989895 444 978 956,484 935,441,352 31-273 9-926 001022 990339 444 979 958,441 938,313,739 31-289 9-929 001021 990783 443 980 960,400 941,192,000 31-305 9-933 001020 991226 443 981 962,361; 944,076,141 31-321 9-936 001019 9916-69 442 982 964,324 946,966,168 31-337 9-940 001018 992111 442 983 966,289 949,862,087 31-353 9-943 001017 992554 441 984 968,256 952,763,904 31-369 9'946 001016 992995 441 985 970,225 955,671,625 31-385 9-950 001015 993436 441 986 972,196 958,585,256 31-401 9-953 001014 993877 440 987 974,169 961,504,803 31-416 9-956 001013 994317 440 988 976,144 964,430,272 31-432 9-960 001012 994757 439 989 978,121 967,361,669 31-448 9-963 001011 995196 439 990 980,100 970,299,000 31-464 9-966 001010 995635 439 991 982,081 973,242,271 31-480 9-970 001009 996074 438 992 984,064 976,191,488 31-496 9-973 001008 996512 437 993 986,049 979,146.657 31-512 9-977 001007 996949 437 994 988,036 982,107,784 31-528 9-980 001006 997386 437 995 990,025 985,074,875 31-544 9-983 001005 997823 436 996 992,016 988,047,936 31-559 9-987 001004 998259 436 997 994,009 991,026,973 31-575 9-990 001003 998695 435 998 996,004, 994,011,992 31-591 9-993 001002 999131 434 999 998,001 997,002.999 31-607 9-997 001001 999565 1000 1.000.0001,000,000,000 31-623 10-000 001000 The common Logarithm of any number is the power to which, if 10 be raised, the said number is the result thus : 10 2 = 100 therefore Log. = 2- 10 2 - 42 = 263 = 2-42 10- 2 - 42 = .0263 =2-42 To multiply by the aid of logarithms add the logarithms of the numbers together and find the corresponding number of the logarithm obtained. To divide lij the aid of logarithms subtract one logarithm from the other. To extract any root divide the logarithm by the index of the root and find the corresponding number of the logarithm obtained. To raise a number to any power multiply the logarithm of the number by the index of the power, and find the corresponding number of the logarithm obtained. To fi?id proportion by the aid of logarithms add together the logarithms of the second and third terms and subtract the logarithm of the first term ; the answer is the corresponding number of the logarithm obtained. GAS ENGINEER'S POCKET-BOOK. Areas and Circumferences of Circles. AREAS AND CIRCUMFERENCES OF CIRCLES. 25 ^ r u^ if} ift iQ \r\ j^-s i<^ |^ ^ ^ ZO Z& CO ^O - - t^" t^- t- l^- ^ccccccccioeococococowoococcicccccccccccccoccccco socsoiaio^csaiooooooooooooooi-irHS >a , . .- . . . . ^ ; r _,^H^H^I^HC< 1 CjCH -* t< -t< ic ic ic c c ic ic c c 5 o m o ic Q ic >c ic is is 10 ia ic m >c ic ic ws in 10 ic in is m oCi-HO5(M(NOO'*i>Ct-. Ci-Ht^COGOC>OiOiiCr-l(M-** OO OO OO OO OO OO OO C30 GO C^ O^ Ci O5 Ci Oi Ci O O O O O O QCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCO"*'*-*'*-*-^ AREAS AND CIRCUMFERENCES OF CIRCLES. 27 28. GAS ENGINEERS POCKET-BOOK. ^ ,-H ,_| rH * O ^ > - tC C"i O O "X) f: cp cc Ci i^ -t--lSC5Or-HiSOl(p iisaococorHcc'*isb^t*ooJHeo < aiiO5pfc-aopi-ieiei5 < * 1 B to H o 4n -H i*s i"- oo o cO CO b- OO O5 rH CC IS '-b b- OO rH rt< IS i I"- O5 rH SC -t< S '- <3 IS IS IS IS IS IS CO CO CC CO tO tO b- b- b- b- b- b- OO OC CC X X V. Hw -It nfco HN *l=o "I" 1 "-I" OrH (NCp rH a CO b-t30 O> AREAS AND CIRCUMFERENCES OF CIRCLES. 29 ' 10 - c CO -H O bcboiOcboobo tOtOt-t-t-t^-OCGCGCGOOOOiOiOiOi OiOiOiOiOiOiCiOiOiOiOiOiOiOiOi O ^ 5 " C-lGpt-rH-rHfOC^rHrHitprHrH b o N CO CC CO -t< *-t< -** -HH -HH i<2 1C 1C O JO OiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOi S O CO . O G^ Oi Oi tO O rH 'SGOCOCOCOCOGOCOCOQCCOOOCOCOCOCOGCCOGOGCGOOiOiOi SO OO OO O> Q i-< C " fr> Cp rH ^ -r4 O O l> O> O rH CO ^ Q ! O O O *-H rH rH rH rH C^ d C^ C^l 71 CO CO CO CO CO '"f* "Hr 1 "H^ -Hj^ 1.C IQ OOCOCO^OOCCCGOGOOCGCCOCC'CX.OOaOOCGCGOGOCCCOGOOOCO a 00 O O OO rH rH t- CO -^ CO * O O Q GO OO * O rH gcp^^t-OiCprHCp^ip^pt-OiTlC^lCp-^ipt-OiOrH^cp .-OiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOiOOOO ii ^ ^ ^ Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi Oi O 75 CC O O CC O5 f^ 30 GAS ENGINEER'S POCKET-BOOK. B oo O * 04 oe " < t O O J-H Q te^a O O < t> to 9 H o i i< 9 *< c oo *e W 'M M 'M (M i>) <>\ S t> OO O rH C-l CO M C^ IM C i o b- 30 o rH e -*> rH CO - lO (^ tp t- p 00 rH CO >p -f 1C O Op 1C O rH O 00 -* HH < -* i in >n > 10 io n p > ? -H -H ^H -n -H -H -H ^ ^H -* * * ^ -H ^ -* -* -^ t- o . o rH n o > l-rH?ai1t3rH M C<1 GO -M C<1 GO OO OO >^ lO lO >C iO 1C lO lO lO >C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C O iC 1C 1C O C 1C tO 'O tO tO 'O tO to l~~ t-~ l-- b- h- h- b- t- 30 WCCCCJCCCCCCOCCCCICCOICIOtCJCCCCCJCCCCCICICCO 32 GAS ENGINEER'S POCKET-BOOK. ic cc oo cs o r (c ^H < I r I (M - b- t- GO GO \ !>1 n ic c ic c >c ic c >c >c >c >c uc us c c >c Ci CS O O O O O O O ^+*-4.oi ol el -44 09 e & is is c ic ic c ic o O 1C 1C >C 1C 1C 1C 1C 1C 1C 1C 1C >C 1C 1C 1C 1C 1O 1C 1C 1C 1C 1C 1C -^ O (f-1 4rl t- O CC 1^ O CO 1C b- s 'T-l n iC 00 -1 1C 00 n CSOOOi-l ' -H i-H (M 5O SO CC CO aCC5C5C5C5CVJiCSC5asOSOlCS I- ^H T-H (>1 Cp -^ ? l^ CJD O O r-l CO ^ p 00 OS OS i?q CO -H 1C p b- C 1C 1C IS 1C 1C 1C iC 1C 1C 1C 1C 1C 1C fH O f^ 1^ O CO GO O> CX> i^l ^H OO t-* O Ij- CO *" <3 fH iH CO ' C3 Ci 1C b- CS C-l -^H 00 01 -* ('- CS AREAS AND CIRCUMFERENCES OF CIRCLES. 33 G.E. GAS ENGINEERS POCKET-UUOK. 10 6r CO ; i lb-o5cododcsooo i<^l?qCOiO>nif oooooooooooc _ _ _ _ _ _ _ _ CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO \ _J CO I (N6 g r^ O 3 HS R-I9H9 AREAS AND CIRCUMFERENCES OF CIRCLES. 35 'OOOOOOOOOO 'COWCOCOCOCOMCOCO^-*^-*-*^-^-*'*-*^^^-*^ IcsC^C^CO^lOt OOOi lrHC^^I>l>CJO^CpTHiOI>l>Op l&ooooooo^T^FHT^r^T^F^T^fNiN^ifqcq^cqeq ^ii^NC^C^C^C^^C^C^C^INtNlNfNfNC^C^C^C^C^C^MfNffCI PI o i ^^^^^cccococococccocc^wwwSM^^cocococo r^ O co 05 "^ co co co co co co co co co co co co co co co co co co co co co co co co w o I 00 CO I CO CO CO CO CO CO CO to" CO CO CO CO CO CO CO CO t^* ^ l>- t^* 6^ l^ t* t** 'cocococococococococococococococococococococococo [o o ^o ^o ; ^H i fH ^TH ZH ^* 4n An i IH ^ tt co co l>- OO OO QO OO OO OO OO Ci ^ C5 C5 Gi OS Oi O O O O r5C iC CO CC CO CO CC CO CC CC CO t* t> t~~ t* t> lr* OC' OO OO OO OO OO co^^^^^^^^^^cccc^cx^w^cccccccccccc in I ^^^^^^^^^^'^^^^^^^^i^wbiatQicibid s < p I 'MIMfMlMtMlMCOOOCOCCCCCOCOCOCCCCCOCCCCCCCCCCCOCO _C ^cbdi^OO^OSCCOOrHCCC^C^THt^C^cbr- (t-i (COCirH O5O5OiOOi-Hi IC^C^COCO-^lCi-COtOtCt^t^CCOOCOOl ~ (N(MC CO O5 O5 O5 O w|- H* HS 2|2 SS AREAS AND CIRCUMFERENCES OF CIRCLES. 37 CO CO CO CO CO CO CO tO CO CO CO CO CO CO CO CO CO CO CO CO iCiCiClClClCiCiClCiOiCiClClCiCiCiCiCCOCOCOCCCCCO 1C 1C 1C 1C 1C >O lO C 1C 1C C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C O 1C 1C 1C 1C -t>-t>-t-COCX)CCQOQOOOaOCOOOOOQOCOODOOOOOOCOCOCC GAS ENGINEER'S POCKET-BOOK. AREAS AND CIRCUMFERENCES OF CIRCLES. 39 0) i-i <- l>- l> t^- l>* !> !> Ir* t*- l>" t* t^ t^ !> t^ CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO GO GO GO GO GO 05 . iooaicoiooioiaioioioir5^noinocococococos ti i t ? ? i> t- t> b- t- i>- ooooooooooooooooooooo cooooooooooooooooooooooo jjccfdcccocoeccocccceccccccccccoccccccccccececeoco ooooooooooooooo MCCCOCCCOWCOCOCCWCOCOCCCCCO b- CO Oi O PROPERTIES OF THE CIRCLE. 41 To find Area of a Segment of a Circle. From the area of a sector having same arc subtract the area of triangle whose 2 sides = radius of circle and base = chord of segment. The volume of a sphere = diameter 3 x -5236. Area of oval = major diameter x minor diameter X '7854. To find the Length of a Side, the diameter being given : For a Hexagon, multiply the diameter by *577 Octagon, . ., '414 Decagon, -325 Dodecagon, ,, -268 The square of any number containing a fraction equals the whole number multiplied by its next higher digit -4- the square of the fraction, as follows : 2 = 8 X 9 +1 2 = 8 X 8J + i 2 = 8 X 8i + Properties of the Circle. Circumference = diameter X 3-1416 or 3i. Diameter x '8862 = side of equal square. Diameter x '7071 = inscribed square. Diameter 2 X '7854 = area of circle. Length of arc of circle = no. of degrees X "017453. f Cosine Radius GAS ENGINEER'S POCKET-BOOK. i co o co o ^ US l^H Cl r* r-( M & !3<0 n i> Oi J O >~*< CO O i !o o I II II K? 00 ^ .2 s a & & (M 97^ all? I? "S5 C0 i I i-l ^Q O O i-l CO 00000 ** N oo ** > o r-t * * eo 10 i CN| O O i-H r-t r-l ! O C6771 '7604 8438 9271 tf 0130 '0964 1797 2630 3464 4297 5130 5964 -6797 '7630 8464 ,9297 0156 -0990 -1823 2656 3490 4323 '-5156 5990 -6823 '7656 8490 9323 T 32 0182 -1016 1849 2682 3516 4349 ' -5182 6016 ,'6849 >7682 8516 9349 i 0208 1042 1875 2708 3542 4375 1-5208 6042 -6875 ,'7708 8542 9375 A * 0234 1068 1901 2734 3568 4401 i '5234 6068 ,-6901 '7734 8568 9401 A 0260 I-1094 1927 2760 3594 4427 5260 6094 -6927 '7760 8594 9427 tt 0286 1120 '1953 2786 3620 4453 5286 6120 -0953 '7786 8620 9453 i 0313 1146 i'1979 2813 3646 4479 5313 6146 '6979 i'7813 8646 9479 It 7 0339 1172 2005 2839 3672 4505 5339 6172 j-7005 |-7839 8672 9505 T ? ff 0365 1198 2031 2865 3698 4531 5365 6198 -7031 7865* 8698 9531 ft 0391 1224 2057 2891 3724 4557 5391 6224 '7057 7891 8724 9557 i 0417 1250 2083 2917 3750 4583 5417 6250 7083 7917 8750 9583 tt 0443 1276 2109 2943 3776 4609 -5443 6276 '7109 -7943 8776 9609 ft 0469 |-1302 2135 2969 3802 4635 '5469 6302 '7135 -7969 8802 9635 H 0495 i-1328 2161 2995 3828 4661 '5495 6328 7161 7995 8828 9661 1 0521 -1354 2188 3021 3854 4688 j-5521 6354 7188 8021 8854 9688 tt 0547 :-1380 2214 3047 3880 4714 -5547 6380 7214 8047 8880 9714 H 0573 -1406 2240 3073 3906 4740 -5573 6406 7240 8073 8906 9740 If 0599 ;1432 2266 3099 3932 4766 5599 6432 7266 8099 8932 -9766 I 0625 '1458 '2292 3125 3958 4792 5625 6458 7292 8125 8958 9792 it 0651 1484 i -2318 3151 39S4 4818 5651 6484 7318 8151 8984 9818 H 0677 '1510 i'2344 '3177 4010 4844 5677 6510 7344 8177 9010 9844 H 0703 -1536 '2370 '3203 4036 4870 '5703 6536 7370 8203 9036 9870 1 0729 >1563 ;-2396 3229 4063 4896 -5729 6563 7396 8229 9063 9896, 0755 1-1589 1-2422 3255* 4089 4922 5755 6589 7422 8255 9089 9922 if -0781 -1615 -2448 3281 4115 4948 5781 6615 7448 8281 9115 9948 H 0807 1641 2474 3307 4141 4974 5807 6641. W4 -8307 9141 9974 Ounces in Decimals of 1 Ib. Ozs. "Lbs. Ozs. Lbs. Ozs. Lbs. i 015625 5 3125 104 65625 i 03125 5 34375 11 6875 I 046875 6 375 114 71875 1 0625 6* 40625 12 75 H 09375 7 4375 12| 78125 2 125 7i 46875 13 8125 2* 15625 8 5 tat 84375 3 1875 8| 53125 14 875 S| 21875 9 5625 14i 90625 4 :25 9ft 59375 15 9375 ^ 28125 10 625 M| 9687 DECIMALS OF 1 TON. Decimals of 1 Ton, COCOOlCOC^OOuSi-HaO^rHt^-* CO CO COC-i I O i llQOlCOS''*iOSCOCOCCt>>COOOOSOSOOi 1 i li-HCNCNlCO?O^I'^iOlO COOSCO-* CO CO O-* tO-OOOOOOOSOlOOrHT-H OOOOOOOOOOOOOOOOOOOrHr-(rH^H co GO GO GO GO GO CC OS OS OS OS OS OS OS O O O O O O O O O O O O O CO CO t^ l>" COCOOSCO(NQO>Oi (QO-^i I COCOOSCOOrHOO-*i-tl>"* COCO "*O5COCOCOt>WC-i i C OS CO GO i I CO O 1C O t>-* tOCO O !M CO C 00 CO t^ i-l tO O eo aOGOOOCOODCOOSOsOSOS O-l C~^ C 1 ! tOCOOStO -*oscppocot--c-^' N 65 c I OS **< COS^OSCOGOC^t^fNtOi-HtOOtC >J-0^-l>CO-*O.COCO(Mt--r- (f.O-COCO;^P^i^t^^o6oobqC OS ^ GO CO t^~ *~^ tO O *C OS "^ GC CO ^^* C^ o to to to to to to to to to to to to to to to to t^ i>* t^* ^ i>* t'* f* t^* tOCOO5tOCC i >C 1C 1C C 1C C 1C 1C C C XC 1C S 1C tO O to| tO tO o DECIMALS OF 1 TON. 51 iCC;cOGCi?-lt>'rHCOOiCC}''lCOCCt> t ' iCOCiC t^- l>- QC GO O O3 O O r I i I i ! C^l C^ CO CO -f -*< C '~ >^ O C l^- t>- OO CO C5 CS 5oopot-t^cccccr. c^ciOOi-ti-te^cqeoeow^-*ooowfr (>1 * oo eo t ^ o o >o o ^** QO eo i- I i i b-t-t*t-ttb-oooOGOooooQ666o6a6QbabooQOooooao cocococococococococococococococococococococococococococo C^GOlCrHGO-^jHOJ^ CO CO CO ** TH 1C 1C CO CO *> GOGCGOGOGOGOGOGCCOCO -(MCOi ICOOlO OiCOQO(Mt-i lOOiCC5-+iGOCOt-i ICOOiCO-rtHCOCOt^(NCOi llO -i-i CO' cocococoeococococococococococococococococococoeococococo OCOC5CO(MCOli-ICO-*^Hl>-'*i eOCOa>COi ICOi llCOiCO5-*lC5COCOC-(7>r-*COi-HlCOlCO5-*iC!COaOC 1C 1C ip COCOOSCOC*Hi-lO>'* 1C 1C 1C 1C 1C ip ip 1C 1C 1C 1C 1C ip 1C ip ip 1C 1C ip 1C 1C 1C ip 1C 1C 1C ip C i tOO-^i (t^-^l COCO COC-^ ~ O5 *< O5 CO " ip 1C 1C ip 1C 1C 1C 1C ip 1C ip ip 1C p 1C 1C ip 1C 1C 1C ip 1C 1C 1C ip ip 1C 1C COCOO5CO-*l COCO CO(MOOCi-(00-*i-HO-* ip 1C 1C ip 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C ^Ir-lt^-^ COCO CO-^*l COCO t 1 * l>- OO OO GO OO OO OO 66 GO OO OO CO OO OO GO OO GO COCOCSCO-IOO-*l!-lOS'COCOC-f ICOO 'fe g 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C 1C O 1C 1C 1C 1C 1C 1C 1C CO CO CO CO CO J DECIMALS OF 1 TON. 53 rHOO^i-Ht^-*! CO CO s CO CC CO CO CO CO ^ "*+< i l(?l(MCOCO'^l - ^llplOlOCpCOl--tOOQOOS ^ TfH ^H -^ ^ ^H ^ t> t- b t !> 10 i i co M< i i os **< I-H co o 10 t- ,-H CO O COCOOSCO(MQOiOi-lOO^i-lt>"* COCO COlMOOlOrHCO^i-lOS-*! ^OSCOCOCOt^fNt^r-ICOr-liCOiOOSitlOSCOCOC^t-CNlCOi ICOOlO OrHi-HC<|IMCOCO'^l'^l'^llOlCCOCOl>-b-OOGOOOOSO5OOi li I 0000000000000000- cococococococococccocococococococo cccococococococococo COCO OCS^ COCOCOCOCOCOCOiOCOCOCOCCCOCCCOCOCOCOCOCO OOQOOOOOOOQOOOOO COCOCOCOCOCOCCCO CO CO CO CO CO CO CO to CO CO CO CO CO CC CO CO t^- IT lr l>* t~ l>- l>- l>- t> l>- l> CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO ^COCOb-< OOi ii ii 10 m io ic m 10 10 i^ c o 1 COCOCOCOCOCOCOCOCOCOC COCO CO- -*l COCO CO(Bco fi cocooicoc^aoini --ti coco coc^coini 100^1 i --- t~* t^- t~^ ^^ t>- t* t>- cococ>cc(Mooini loo-^i it^-ti coco coc 'oc'fi-HCi-* o o 23 I-H ^ - t" GO GO G^ Gi OOGOQOGOOOQOGSGJGJGJGSGJGJGSGSGiGJGJGSGSGiGiGSGJGSGiGiGi GSG5G>GJGJGSG5G5GiG5G5G5G5GJGSGSG5G5G5G5GiG5GiGSGSG5G5GJ GJ Gd Gd Gd Gd Gd G) Gi G) G} G) - G - - aOQOOO - Gd _. G) . G^ . G) OCCGJ5CS-'*' O Gs mOiCCOOfMt^r-HtCOinGl^GOCOt^i-HCOOiCGJ^QOCOt^lMySrHlO t t co co o o o o 1-1 i-t fH e"* o o o o C5 O^ Ci C5 GT5 tOCO ^GS-^ CCOlGOiOi (GC^i-HO^^ t** QO OO OO O$ Gi O O f^ rH C^ OOOOOOi-H^Hi-Hi-Hi f O O) O O C* O G^ C"i C". G) Ci GAS ENGINEER'S POCKET-BOOK. Equivalent Weights. Metric. English. 1 milligramme = -0154 grain. 1 centigramme = -1543 1 decigramme 1-5432 1 gramme = 15-4323 1 decagramme = -3527 oz. 1 hectogramme = 3*52/4 1 kilogramme = 2-20462125 Ibs. 1 millier or tonne = 19-6841 cwts. English. Metric. 1 grain = 1 drachm = 0648 gramme. 1-7718 1 oz. = 28-3495 1 Ib. = 4535926 kilogramme. 1 stone = 6-3503 1 quarter = 12-7006 1 cwt. = 50-8024 1fr\n I 1016-048 l/OIl - -s 1-01605 metric tonne. Equivalent Liquid Measures. Metric. English. 1 centilitre | . 10 cubic centimetres |" U17b P mt 1 decilitre = -1761 1 litre = -2201 gallon. 1 decalitre = 2-2009 1 hectolitre = 22-009 1 cubic metre = 220-09 English. Metric. 1 gill or quartern = -1420 litre. 1 pint = "5679 1 quart = 1-1359 1 gallon = 4-5435 Equivalent Measures of Length. Metric. English. millimetre = 03937 inches. centimetre = 3937 decimetre = 3-93704 metre = \ 39-3704 3-2809 feet. decametre = 32-8087 ,. hectometre = 109-3623 yards. ( 3J80-369 feet. 1 kilometre = < 1093-623 yards. ( 62138 mile. EQUIVALENT MEASURES OF LENGTH. 57 English. linch 1 link 1 foot 1 yard 1 fathom 1 rod, pole or perch 1 chain 1 furlong Imile 1 admiralty knot or nautical mile Metric. 25'4 millimetres. 2012 metre. 3048 91439 1-82878 5-02915 20-11662 201-1662 0-20117 kilometre. 1609-3296 metres. 1-6093296 kilometres. 1-85315 Pounds Square inches Circular inches Cylindrical inches Cubic inches > feet Cylindrical inches feet Cubic inches Cylindrical inches 00893 = cwts. 00045 = tons. 007 = square feet. 00546 = 0004546 = cubic feet. 00058 = 003607 = imperial gallons. = Ibs. avoirdupois of wrought iron. steel. copper. brass. X X X X X X X X 6-232 = X '002832 X 4-895 X '281 283 3225 no:? 7 26 4103 2636 4908 2168 2223 2533 2385 2042 3223 207 3854 zinc. lead. tin. mercury. wrought iron. steel. copper. brass. zinc. lead. tin. mercury. Metric Equivalents. To convert grains into grammes grammes into grains drachms into grammes ounces (avoirdupois) into grammes pounds cubic centimetres into grains drachms ,, ., ounces (avoirdupois) pints into cubic centimetres litres into ounces (avoirdupois) gallons into litres 0-065 15-5 3-9 28-4 453-6 15-5 0-29 0-036 X 473 X 35-5 X 3-8 58 GAS ENGINEER'S POUKET-BOOK. To Convert Grammes, Decigrammes, Centigrammes and Milligrammes to Grains. 1 gramme = 15 '4323 grains. 2 = 30-8646 ., 3 v =46-2969 4 ., = 61-7292 5 = 77-1615 6 grammes = 92-5938 grains. 7 ., = 108-0261 ., 8 = 123-4584 ., 9 = 138-8907 For the number of grains in a decigramme shift the decimal point one place to the left, thus, 1 decigramme = 1-54323 grains. For the number of grains in a centigramme shift the decimal point two places to the left, thus, 1 centigramme = -154323 grains. For the number of grains in a milligramme shift the decimal point three places to the left, thus, 1 milligramme = -0154323 grains. Cubic Feet into Cubic Metres. Cubic feet. Cubic metres. Cubic feet. Cubic metres. Cubic feet. Cubic metres. Cubic feet. Cubic metres. 1 0283 31 8778 61 1-7272 91 2-5767 2 056!) 32 9061 62 1-7555 92 2-6050 3 0849 33 9344 63 1-7838 93 2-6333 4 1133 34 9627 64 1-8122 94 2-6616 5 1416 35 9910 65 1-8405 95 2-6899 6 1699 36 1-0193 66 ' 1-8688 96 2-7182 7 1982 37 1-0477 67 , 1-8971 97 2-7466 8 2265 38 1-0760 68 1-9254 98 2-7749 9 2548 39 1-1043 69 1-9537 99 2-8032 10 2831 40 1-1326 70 1-9820 100 2-8315 11 3115 41 1-1609 71 2-0104 200 5-663 12 3398 42 1-1892 72 2-0387 300 8-494 13 3<>S1 43 1-2175 73 2-0670 400 11-326 14 3%4 44 1-2459 74 2-0953 500 14-157 15 4247 45 1-2742 75 2-1236 600 16-989 16 4.~>30 46 1-3025 76 2-1519 700 19-820 17 4814 47 1-3308 77 2-1803 800 22-652 18 5097 48 1-3591 78 2-2086 900 25-483 19 5380 49 1-3874 79 2-2369 1.000 28-315 20 5663 50 1-4157 80 2-2652 1,500 42-472 21 5946 51 1-4450 81 2-2935 2.000 56-620 22 6229 52 1-4724 82 2-3218 2500 70-787 23 6512 53 1-5007 83 2-3501 3000 84-944 24 6795 54 1-5290 84 2-3785 4000 113-240 25 7079 55 1-5573 85 2-4068 5000 141-574 26 7362 56 1-5856 86 2-4351 6000 169-888 27 7645 57 1-6140 87 2-4634 7.000 198-184 28 7928 58 1-6423 88 2-4917 8000 226-480 29 8211 59 1-0701; 89 2-5200 9 000 254-814 30 8494 60 1-6989 90 2-5483 10.000 j 283-148 OUBIO METRES INTO CUBIC FEET. 5-9 Cubic Metres into Cubic Feet. Cubic Cubic Cubic Cubic Cubic Cubic Cubic I Cubic metres feet. netres feet metres feet. metres feet. 1 35-3156 31 1094-7836 61 2154-2516 91 3213-7196 2 70-6312 32 1130-0992 62 2189-5672 92 3249-0352 3 105-9468 33 1165-4148 63 2224-8828 93 3284-3508 4 141-2624 34 1200-7304 64 2260-1984 94 3319-r><>64 5 176-5T80 35 1236-0460 65 2295-5140 95 3354-9820 6 211-8936 36 1271-3616 66 2330-8296 96 3390-2976 7 247-2092 37 1306-6772 67 2366-1452 97 3425-6132 8 282-5248 38 1341-9928 68 2401-4608 98 3460-9288 9 317-8404 39 1377-3084 69 2436-7764 99 3496-2444 10 353-1560 40 1412-6240 70 2472-0920 100 3531-560 11 388-4716 41 1447-9396 71 2507-4076 110 3884-716 12 423-7872 42 1483-2552 72 2542-7232 120 4237-872 13 459-1028 43 1518-5708 73 2578-0388 130 4591-028 14 494-4184 44 1533-8864 74 2613-3544 140 4944-184 15 529-7340 45 1589-2020 75 2648-6700 150 5297-340 16 565-0496 46 1624-5176 76 2683-9856 160 5650-496 17 600-3652 47 1659-8332 77 2719-3012 170 6003-652 18 635-6808 48 1695-1488 78 2754-6168 180 (1356-808 19 670-9964 49 ' 1730-4644 79 2789-9324 190 (1 709-964 20 706-3120 50 1765-7800 80 2825-2480 200 7063-120 21 741-6276 51 1801-0956 81 2860-5636 250 8828-900 22 776-9432 52 183(5-4112 82 2895-8792 300 10594-468 23 812-2588 53 1871-7268 83 2931-1948 350 12363-46 24 847-5744 54 1907-0424 84 2966-5104 400 ;14126-24 25 882-8900 55 1942-3580 85 3001-8260 500 1 7657-80 26 918-2056 56 1977-6736 86 3037-1416 600 21189-36 27 953-5212 57 2012-9892 87 3072-4572 700 24720-92 28 988-8368 58 2048-3048 88 3107-7728 800 28252-48 29 1024-1524 59 2083-6204 89 3143-0884 900 31784-04 30 1059-4680 60 2118-9360 90 3178-4040 1000 38847-16 Demy . Medium Royal . Imperial Elephant Sires of Drawing Paper. 20 X 15 22 X 17 24 X 19 31 X 21 27 X 23 Columbier . Atlas . Double Elephant . Antiquarian . Emperor . 34 x 23 . 33 X 26 . 40 X 26 . 52 X 29 . 68 X 48 60 GAS ENGINEER'S POCKET-BOOK. Colours used in Architectural and Engineering Drawings. For Brickwork in plan or section (to be executed) Brickwork in elevation. Flintwork or parts of brick- work to be removed Granite . Cement or Stone . Concrete . Clay Earth . Plaster . Slate Tiles .... Wood English Timber, not Oak . Oak or Teak Fir Timber . Mahogany . Iron, wrought cast . Lead Copper Brass Gunmetal .. Glass Leather . Meadow land Sky effects . Crimson Lake or Carmine. Venetian red or Crimson Lake and Burnt Sienna (light). Prussian Blue. Violet Carmine. Sepia. mottled with Burnt Umber. Burnt Umber. Sepia (light). Indigo with Crimson Lake. Indian red. Burnt Sienna. Raw Burnt Indian yellow. red. Prussian blue. Payne's Grey. Indigo or light Indian-ink. Crimson Lake with Gamboge. Gamboge. Dark Cadmiums. Cobalt mottled. Vandyke brown. Hooker's Green. Cobalt Blue. Weight of Materials. MATES LAJLS. Weight of One Cubic Foot. Cubic Feet per Ton. Ibs. 37 60A 52 feet = 1 chaldron . . . ""2 Brickwork 100 22| in cement . . . . 110 20 Bricks, red kiln 135 17 common 110 20f London Stock .... 115 19| Welch fire 150 15 Cement, Portland .... 84 26$ cask 4 bushels = . 5 feet 2 cwt. Roman 60 37* cask 5 bushels = . . 6 feet 4 cwt. Chalk 140 to 166 15 to 13J Clay . .... 120 to 135 18| to 17 WEIGHT OF MATERIALS. 61 MATERIALS. Weight of One Cubic Foot. Cubic Feet per Ton. Ibs. Coal, Cannel and Welsh . 84 26f Newcastle 80 28 Coke 47 48 Concrete 120 18} Earth 95 to 126 23J to 18 Flint 164 13| Glass, Crown . . 157 Flint 187 12* Plate. ... 184 12i Gravel 112 to 120 21f to 18 Iron, cast 450 5 wrought 487 4f Lime, stone 53 42 chalk 44 51 Mortar, from (old) .... 88 25^ ,, to (new) 119 19 Sand, pit 90 23^ to 25 river 118 19 Shingle . .. ... Slate .. . 13i ., Purbeck ... 133 Yorkshire Craigleith ... ill Derby ... 15 Portland ... 14f Bath ... 16 Marble 12J to 13 Tiles, average 112 20 Oil of Turpentine 54| 41 Linseed 58f 38 Whale 57| 39 Rain Water (252 gallons per ton) 35 Sea (224 ) . . 64 35 Gallon of water = 10 Ibs. = 211 \ cubic inches. 6J ,, = 1 cubic foot nearly. Roofing 1 square of 100 feet slating = 10 cwt. and timbers = 15 tiling = 15* and timbers = 21 .. ,. with 7 Ib. lead =10 ,, , and timbers = 17 , with 6 Ib. lead = 8 , and timbers = 15 with 16 gauge zinc = 3 1 ., , and timbers = 10J 62 GAS ENGINEER'S pocKET-BooK r Miscellaneous Articles. One barrel of tar = 2G gallons. Battens = boards 7 inches wide. Bushel of coal = 80 Ibs. coke = 45 quicklime = 70 Chaldron of coal = 25 cwts. coke = 12i to 15 cwts. Fodder of lead = 19J cwts. Hundred of deals = 120 in number. nails =120 Load of bricks = 500 lime (1 ton) = 32 bushels. sand = 36 Planks = boards 12 inches wide. Sack of coal = 224 Ibs. Square of planking = 100 superficial feet. slate =100 Weight of Ear Cwt. 1 cub. yd. sand . . = 30 1 ,' gravel . = 30 1 , mud . . = 25 1 , marl . . = 26 1 , clay . . = 31 1 , chalk . .'= 35 to 36 1 cannel coal = 81 to 87 ths, Rocks, etc. 1 cub. yd. sandstone 1 shale . 1 ., quartz 1 ., granite . 1 ., trap . 1 slate . Cwt. . = 39 . = 40 . = 41 . = 42 . = 42 . = 43 Natural Slopes of Earths with the Horizontal or Angles of Eepose. Gravel, average . 40 and sand mixed . 38 Dry sand . 37 to 38 = 1-33 to 1 Sand .... . 21 to 22 = -263 to 1 fine dry . 32 Vegetable earth or peat . 28 = 1-89 to 1 new . . 34 Compact . 48 to 50 = -09 to 1 Loamy . 40 = 1-2 to 1 Shingle, average . 39 to 40 = 1-2 to 1 clean. . 36 Rubble, average . . 45 = 1 to 1 Clay, well dried . . 45 = 1 tol stiff or dry mud . 45 as 1 to 1 wet, average . 16 ., London . 15 Coal 33 = 1-66 to 1 1 cub. yd. rock in large pieces = when excavated 1*50 c. yds. 1 medium as dug = .. 1 -25 to 1-30 c. yds. 1 chalk . . . . = 1-30 c. yds. 1 .. sand and gravel . = ,, 1*07 1 clay and earth . . = .. 1-2 to 1-25 c. yds. RESULTS OF POWER. Observed Eesults of Power (Nystrom). 63 Work Effects Description of Works. hours per Force. Velocity of ft. Ibs. per Horses. day. second. A man can raise a weight by a single fixed pulley . . 6 50 0-8 40 0-072 ., working a crank 8 20 2-5 50 0-090 onatreadwheel(horizontal) in a tread wheel (axis 24 .8 144 0-5 72 0-130 from vertical) . . . 8 30 2-3 69 0-125 draws or pushes in a hori- zontal direction 8 30 2-0 60 0-109 pulls up or down . . . 8 12 3-7 44-4 0-080 can bear on his back . 7 95 2-5 237-5 A horse in a horsemill, walking moderately 8 106 3-0 318 0-577 running fast 5 72 9 648 1-178 An ox in a horsemill walking moderately 8 154 2 308 0-518 A mule 8 71 3 293 0-308 An ass 8 33 2-65 87-4 0-160 On bad foot roads like those in Peru a man can bear . . . 10 50 3-5 175 Llama of Peru can bear 10 100. 3-5 350 Donkey can bear . . . 10 200 3-5 700 Mule can bear 10 400 5-0 2000 Man Power. Efforts exerted for short periods of time. R.A. rule. Pushing a load horizontally .... 100 Ibs. Pulling 70 Tractive force in dragging a cart . . . 40 Lifting a weight from the ground by the hands .150 Carrying on his shoulders 120 On a winch for continuous work . . . .15 to 20 Ibs. When a number of men are pulling on a rope, the effort per man will average very much below the above quotation, and the greater the number the less the average per man. 24 men will not pull half as much again as 12 men. The most advantageous application of a man's power in hauling is in a slanting direction downwards, as his weight is added to his strength. Power of Horses. Rate (miles per hour) =2 3 3 4 4J 5 Tractive force in Ibs. = 166 125 104 83 62 41 64 GAS ENGINEER'S POCKET-BOOK. To set out a perpendicular measure a base of 4 parts, perpendicular measuring 3 parts and diagonal 5 parts. To Divide a given Line into any number of Equal Farts. Let A B be the line to be divided, then at B erect perpendicular B C, then on the line A C set out the divisions by any convenient scale, and from the points as D E F draw lines perpendicular to A B, which will cut at G H K the divisions required. This method is useful for making scales to uneven dimensions. Excavating. A man can dig from 5 cubic yards in hard gravel to 10 cubic yards in loose ground per day. 1 ton of light soil =18 cubic feet. Carts usually hold 2 tons or 45 cubic feet. Piles driven until they are in firm ground will stand 1000 Ibs. per sq. inch of area of head, but when depending only upon the friction of their sides 200 Ibs. per square inch. On sloping ground step and stair the foundations. A cubic yard of earth, before digging, will occupy about 1^ cubic yard when dug. A dobbin cart will contain f cube yard. Earth waggon, small size. H u large , 3 Wheelbarrow . . . ^ A single load of earth = 27 cubic feet = 21 bushels. A double = 54 1 cubic yard of gravel =18 bushels in the pit. 1 = 24 when dug. When formed into embankments gravel sinks nearly \ in height and decreases \ in bulk. If earth is well drained, it will stand in embankments about \\ to 1. Foundations. 6 of good aggregate to 1 of ground lias lime will answer every purpose in ordinary cases, and should be about a foot wider than the bottom course of footings, or 6 inches on each side. SAFE PRESSURES ON FOUNDATIONS. 65 Whenever large weights occur, as on foundations of columns, angles of buildings, &c., Portland cement should be used in place of lias lime ; the dimensions can be increased if desirable. Foundations in water are formed sometimes by rows of wooden piles so fastened together as to form a pier for the horizontal beams to be fixed upon, as in wooden bridges. A great objection to wooden piles is the fact that in water, fluctuating by the tide, the timber decays at the water-line and therefore requires to be sheathed with copper. The following- Pressures may be used with safety pei- superficial foot for Foundations : Tons. Rock. . . . . . . .13 Chalk 4 Solid blue clay and gravel . . 3 to 6 London clay 2 12 in. by 12 in. piles well driven . . 20 to 30 Well punned ground will sustain 1 ton per square foot, if punned each foot as filled in ; if not, not more than ^ ton per square foot. Gravel, good in foundation will uphold 5 tons per square foot. Sandy gravel, near water, 1 tons per square foot. Foundation always 2 ft. 6 in. below ground line. Tons per sq. ft Moist clay and sand (prevented from spreading laterally) . 1-36 Coarse sand and dry clay 2'27 Firm bedded broken stones on dry clay 3 '18 Loose impermeable beds with piling 1-82 and concrete . . . 2*73 It is necessary at all times to allow sufficient room for men to work in a trench where it has to be excavated more than 3 feet deep. In loose ground a man can throw up about 10 cubic yards per day, but in hard or gravelly soils 5 yards will be a fair day's work. Three men will remove 30 yards of earth a distance of 20 yards in a day. A yard of concrete requires about 3 hours' labour to mix and throw in, or, if in heavy masses and the materials handy, about 2 hours. Burning clay into ballast is done by making a fire of small coal or coke breeze, and casing the same with clay, laying alternate layers of fuel and clay until the mass is burnt through. 2 tons of small coals will burn about 25 cube yards of earth. It is used for roads and concrete walls, and very frequently ground for mortar as a sub- stitute for sand, but it is essential that when used for such a purpose it be well burnt. Value, reckoning coals at 15s. per ton, 2*. Qd. per cubic yard. 19 cubic feet of sand. 18 ditto clay, 24 ditto earth, 15 ditto chalk 20 ditto gravel, will each weigh 1 ton. Footings Projection at bottom on each side should not be less, than half the thickness of wall at base, diminishing in regular offsets, and height not less than projectio \ CUE. V 66 GAS ENGINEER'S POCKET-BOOK. Punn all trenches before putting in concrete for foundations, and drain off all surface water permanently. Sewerage about 5 feet head per mile is required to maintain a flow and to overcome friction in small pipes. Temperature increases about 1 F. for every 60 feet below the level of the ground. Damp Course. This is to prevent the moisture rising in the walls, and should be placed from 6 to 12 inches above Jhe ground line. It can be made of slates laid in Portland cement, but recently asphalte has been adopted and is effective and economical. A glazed earthen- ware damp course, with ventilating spaces through its centre, has also been suggested. Damp Courses for External Walls (Prof. H. Adams) : A course of slates throughout the thickness, 3 to 6 inches above ground line. A double course of slates in cement, 3 to 6 ins. above ground line. A layer of asphalte, j to ^ inch thick, ,, A layer of cement, ,, ., Taylor's patent glazed and perforated stoneware slabs, above ground line. A layer of melted pitch with sufficient coal-tar mixed in to prevent it setting too brittle. A layer of sheet lead 4 Ib. to 8 Ib. per square foot, with 1 in. laps (the best). A layer of asphalted (! " jj j? ?) )j > " = 40 -3 Safe load should equal ^ breaking load. Hard red bricks have sp. gr. 2-136, and will absorb 4-56 % water. Soft 1-981, 8-81 % Fire ., 2-000, 5'17 % 1,000 stock bricks weigh 60| cwts. 1.000 red kiln 63 liOOO paving 45 The essential quality of a brick is hardness, and that it shall not absorb more water than one-sixth its weight. The highly vitrified brick only absorbs one-thirteenth to one-sixteenth its weight. The characteristics of a good brick are : (1) it should be free from flaws ; (2) it should have a good ring when struck ; (3) the surfaces of the sides and faces must be level, not hollow or rounded excepting the u frog" ; (4) the surfaces must not be too smooth, or the mortar will not adhere thereto ; (5) the brick must be well burnt ; and (6) a brick should not contain any white patches nor show small stones or rough particles, when broken. If a brick be made red-hot, and when dropped into water does not break up, it is of very good quality. Bricks, unless of very bad quality, are not much affected by the solvent power of rainwater or the acids it holds in solution. Analysis of a Brick Clay of Average Quality. Silica 49-44 Alumina 34-26 Ferric Oxide .... 7'74 Lime 1-48 Magnesia 5'14 Alkalies . . Water .... 1-94 100-00 English bond consists of alternate courses of headers and stretchers. Flemish bond consists of headers and stretchers alternately in every course. Brickwork in mortar weighs per cubic foot, 100 Ibs. cement 110 1 rod of brickwork requires 1^ cubic yards chalk lime and 3 yards sand ; or 1 cubic yard stone lime and 3 yards sand ; or 36 bushels cement and 36 bushels sharp sand. 4,350 bricks required per rod reduced work if set 4 courses 1 foot high. 1 rod of brickwork weighs about 15 tons and contains 235 cubic feet bricks and 71 cubic feet mortar. 70 GAS ENGINEERS POCKET-BOOK. ii FLEMISH BOND CORNERS. 71 f ^ mo Hi 1 I 4 I fHK [1 i ( 72 GAS ENGINEER'S POCKET-BOOK. A bricklayer should lay 1,000 to 1,500 bricks per day in mortar (1 cement to 3 sand). English bond gives the strongest building possible, and warehouses and other buildings in which strength is essential should be built in this style. The rule for the thickness of walls under the Metropolitan Building Act is, T _HL ~N 1) Where T = thickness to be found, H = height in feet, L = length in feet, N =the constant. 1) = diagonal of the face of the wall. The constant N = 22 for dwelling-houses, 20 for warehouses, and 18 for public buildings. Brick on edge coping should be set in 1 Portland cement to 2 or 3 sand. 1 square of pointing requires 1 bushels sand, \ bushel lime, and small per cent, of cement. To Preserve Scaffold Cords. Dip when dry into a bath of 20 grains sulphate of copper per litre of water and keep in soak for 4 days, then dry. The copper salt should then be fixed in the fibres by a coating of tar ; to do this, pass the rope through a bath of boiled tar, hot, drawing it through a thimble to press back surplus tar. and suspend on a staging to dry and harden. Scaffolding. The putlogs or cross-pieces are generally 6 feet long, one end bearing on the ledgers and the other end resting in the wall ; upon these are placed the boards to form the stage. In scaffolding great care should be taken to see it is well braced. Resistance to tensile strain per square inch of Mortar in Brick joints after setting for 168 days. Common stock bricks, with masons' mortar (1 lime, 2 sand \ smithy ashes) . Common stock bricks, with bricklayers' mortar (1 lime 1 sand, 1 smithy ashes) Firebricks, with bricklayers' mortar masons 27-5 Ibs. 33-8 ,. 28-6 .. 24-0 Masons' mortar loses about 13 % on second mixing, and bricklayers 28%. Bancroft. Crushing load Crushing load per sq. inch. per sq. foot. Portland cement 1 to 1 sand and gravel 1*18 tons 170-.") tons. 1 to 3 ., -81 ., 115-5 .. 1 to 6 -03 91-0 .. Lime and sand lose one-third of their bulk when made into mortar. Cement and sand ., ., Sand in mortar prevents cracking, and makes it go farther ; also permits air to get to the lime while setting. PORTLAND CEMENT. 73 Coarse is preferable to fine sand for cement mortar, up to the size that passes a sieve with 12 and is stopped by one with 16 wires to the inch. Below the grade of sand that will pass 40 and be stopped by 60 wires to the inch there is no practical difference in the value of any sands so far as the size is concerned. The best sand for mortar should, when magnified, show a sharp angular formation, not a round or pisolite grain ; and as the porosity of a mortar affects its hardening, especially in the case of non- hydraulic limes, the size of the grains should be excessively fine. Should be as free as possible from dirt. Good mortar will not part easily when wet, or crumble under finger when dry. Trap or granite sand, when sharp, appears to be the best kind of all for the purpose. A bricklayer's hod measures usually 16" X 9", and =s 1,296 cubic inches. It will hold 20 bricks, or f cubic foot mortar (= nearly a half bushel). Lime, or cement and sand, to make mortar, require as much water as is equal to one-third of their bulk, or about 5 barrels for a rod of brickwork built with mortar. Directions for using Portland Cement. All sand, gravel, broken bricks, or other material used for making the concrete, should be clean and perfectly free from all loamy, clayey, or earthy substances whatever, otherwise failure is sure to result, notwithstanding the undoubted excellence of the cement. Clean cold water should be used, and only just sufficient to mix to the consistency of stiff mortar. The water should be added by means of a can with a large rose, so as to spread the water evenly over the materials, the materials being thoroughly turned over and mixed while this is being done. The use of a bucket should be strictly prohibited, so as to avoid risk of deluging the concrete and washing away the cement. For stucco work only fresh water is to be used. In order to obtain uniformity in the strength of the work, it is necessary that a thorough admixture of the cement with the other material be made the dry mixture should be turned over twice before the water is applied, and again turned over twice in the process of wetting. No more cement should be mixed or gauged up at one time than can be used before the setting process takes place. Cement that has partially set and is mixed up again will never harden properly. For making concrete, six to eight parts of sharp sand or clean rough gravel, to o ae of cement may be used. For stucco work, the sand must be clean, the undercoat should be three parts of sand to one of cement, and the finishing coat, equal parts of sharp fine sand and cement, carefully avoiding mixing the mortar with too much water. The brickwork or other absorptive material on which the Portland cement is to be used must be first well wetted. 74 Careful attention to these directions is most essential to obtain a satisfactory result. When making cement blocks or paving slabs, it is sometimes con- sidered advisable to steep them in a solution of sodium silicate for 10 to 14 days. The cause of disintegration of mortar during frosty weather is the expansion due to the conversion of the water, contained in the mortar, into ice, the expansion equalling a 10 % increase in volume. Facings and Pointing. There is always considerable risk in using a brick for facing, unless it is known to stand the weather ; this is especially the case with red bricks. A great diversity of opinion and practice exists as to pointing. Ordinary Tuck pointing consists of well raking out the joints, filling in with coloured mortar, and then laying on a neat parallel joint with white mortar or stopping. The brickwork is also in most cases first coloured to obtain a uniform appearance. Flat pointing is merely raking out the course joints and filling in again with blue mortar. Lime is much improved if Portland cement is added thereto, and well mixed with it. Roman cement is about one-third strength of Portland cement. Plaster of Paris. Weight per striked bushel = 64 Ibs. cubic foot = 50 The adhesive power of Portland cement is at least f of the cohesive, when new, and in time it will become fully equal to it. L. J. Af elder and R. C. Brown. Cement. Magnesia causes expansion and crumbling or flaking ; Sulphur destroys either stone or concrete. Coefficient of expansion of cement = 0-0000145 iron = 0-0000137 to 0-0000148 The Monier system of making concrete has proved itself from 5J to 12 times as strong as that made in the ordinary way. It has been proposed to coat ironwork which is to be imbedded in brickwork with cement, instead of asphalte or paint. Make concrete in foundations three times as wide as the brick wall to be built upon it. Concrete should be turned at least twice dry and twice wet. About 25 gallons water required per cubic yard concrete. Volume of Spaces per Cent, in Concrete Materials. Limestone, crushed, to pass through 3 inch ring, 51 per cent. A AQ J> 5> 24 ,, 36 2 on Ay 14 42 Gravel, to pass through 24 34 RESISTANCE TO CRUSHING. 75 Shingle 33 per cent. Thames ballast (including sand) . . . 17 Limestone and gravel mixed equally, to pass through 3 inch ring 34 Good concrete will bear 31-6 tons per square foot in compression, and 3'1G tons per square foot in tension. Safe Load that may be put upon a superficial foot on Granite piers . . . = 40 tons (crushing commences at 300 tons) Portland stone piers . . = 13 .. 90 ,, Bath stone piers . = 6 ., 40 Brickwork in cement and sand (1 to 1) . . . = 5 ., ,. 40 Rubble masonry . = 4 .. , 40 Firebrick ...... as 6 .. ., 50 Lias Lime (concrete foundations) . . = 5 ., 20 Ordinary brickwork in lime mortar . . = 3 ., ., 24 Pine (yellow) . . = 34 340 ,. Gravel or stiff clay . . = 2 Resistance to Crushing (Stones). Per square inch. Per square foot. Granite, average 5*4 781 Limestone -. 3-06 441-1 Sandstone 1-87 268'9 Victoria stone (granite and Portland cement steeped in solution of flint), average . . 3'71 534 Ibs. per cubic in. Crushing commences on Sandstone, strong . . . 5,000 to 9,000 ordinary . . 3,000 to 5,000 weak . . . 2,000 Limestone, compact . . 8,000 strong magnesian 7,000 weak 3,000 granular . . 4,000 to 4,500 Chalk 300 to 400 Whinstone .... 9,000 to 17,000 Granite 6,000 to 11,000 Mungall. Safe Resistance to Loads per square foot. Rock 13 tons. Chalk 4 n Solid blue clay and gravel 3 to 6 London clay 2 12" X 12" wood piles, well driven to 4 blows = " 20 to 30 ,' 76 GAS ENGINEER'S POCKET-BOOK. A factor of safety of one-fifth of crushing weight, if the load be dead, and of one-tenth, if the load be live, may be taken. In laying stone the joints should be in contact from face to tail. and be thoroughly wetted on surface before laying. The Test for the Porosity of Stone. Weigh the stone when dry and weigh it after immersion in a pail of water. If a sandstone absorbs not more than half a gallon per cubic foot it is a good building stone. Granite consists chiefly of quartz 50 to 60 per cent., felspar 30 to 40 per cent., mica 10 per cent. ; best with most quartz and less mica. The composition of granite is about Silica 72-07 Alumina 14-81 Oxide of iron . . . . 2-22 Potash 5-11 Soda . .... * ** 2-79 Lime . . . . - ? ' . 1-63 Magnesia. . . . . . '"* 0-33 Water, &c. . ... . -. 1'09 Portland Stone. Average composition : Silica . . . " 1-20 Carbonate of lime . . . 95-16 Carbonate of magnesia . . 1*20 Iron and alumina . . . 0'50 Water s.ncl loss .- . . 1'94 Bitumen Trace 100-00 Sandstone should consist of small grains of quartz and only small quantity of carbonate of lime and no uncombined particles of iron. Bath stone weight is 123 Ibs. per foot cube. York stone weight 156 Ibs. per foot cube. H. Adams. 2 inch York paving weighs per square foot 26 Ibs. 39 52 65 78 Covering 1 Power of Paint. 10 Ibs. white lead . . . \ ' 3 superficial yards, 1st coat. 4 pints linseed oil . . 10 Ibs. white lead . . .\ ' WO superficial yards, 2nd coat. . 1 pints spirits of turpentine ) PAINTS. 77 10 Ibs. white lead 2 oz. litharge . 2 pints linseed oil 113 superficial yards, 3rd and 4th coats. 2 pints spirits of turpentine . J 1 pint varnish will cover about 16 square yards one coat. 100 square yards of painting, 4 coats, will require about 48 Ibs. white lead or colour paint, 4 Ibs. putty, 1\ quarts oil, 1 Ib. red lead, \ Ib. size, 2^ pints turpentine, \ Ib. pumice-stone, 1 quire glass-paper, 1 Ib. driers. Paint should contain 1 pint turps to f gallon raw and \ gallon boiled linseed oil. A good paint for wooden structures should consist of from 66 to 75 per cent, pigment, and the balance oil, c. Boiled linseed oil specific gravity should be '947 Haw ., '932 to -937 flash point ,, 500 F. Oxide of iron paints are said to oxidize their oil and gradually destroy it. White lead = Pb. C. 3 , The effect of sulphur upon white lead is to change the carbonate of lead into a sulphide, which becomes soluble in condensed moisture or rain-water. To Test White Lead. If pure carbonate it will not lose weight at 212 F. 68 grains should be entirely dissolved in 150 minims of acetic acid diluted with 1 fl. oz. distilled water. Plumbago mixed with hot coal-tar forms a good coating for rough ironwork. It is said that none of the metallic oxides, commonly used as pigments, chemically combine with the linseed oil in the painting mixture. Thickness of Sheet Glass. No. or Weight in ozs. per sq. ft. Thickness, inches. No. or Weight in ozs. per sq. ft. Thickness, inches. 12 059 21 100 13 063 24 111 15 071 26 125 16 077 32 154 17 083 36 167 19 091 42 200 78 GAS ENGINEERS POCKET-BOOK. The Average Weight of the Materials Covering and Bearing on Roofs, &c. , may be taken roughly as follows : Description of Material. Weight per Foot Super. Common rafters 7 Ib f-in. boarding 1-Jn. Battens 3-in. by -'-in Felt . 2i 3J If Zinc If Corrugated iron . Slates . $ Tiles .... 20 Wind | pitch about 5 !> ..... ,, V* M Snow Slate, 1 in. thick Paving-stone, 2 in. thick Tiles, 1 in. thick Marble, 2 in. thick 22 25 27 5 15 28 9 28f In calculating the safe load on a floor, from 1^ cwt. to 1 cwt. per superficial foot is generally allowed for ordinary work, and from 2 cwt. to 4 cwt. for factories and warehouses, including the weight of the floor itself. Table to facilitate the Calculation of the Area of any Eoof. Rise or Pitch. Angle. Proportion. One-sixth of span . One-quarter of span . . e > 18 25 26 35 1 to 1-05 or 1 to 1 1-12 1 It 30 00 1 1-20 1 n One-third of span . . 33 42 1 1-20 1 H One-half of span . ':; .. 45 00 1 1-41 1 If Two-thirds of span . . 53 00 1 1-67 1 I* Three-quarters of span 56 20 1 1-80 1 If Equilateral . ... 60 00 1 2-00 1 2 Whole pitch . 63 30 1 2-83 , 1 2 Multiply span by the number found in the proportion column ; this gives the superficial area of the roof on the slope. Load on roof may be taken as 50 Ibs. per foot superficial ; this includes weight of roof, and provides for extra strains thrown on it by snow, wind, &c., from 5 to 6 tons safe load per inch of section of ties. Slates should not be laid at less than 26 with horizontal. SLATING. 79 Roof Coverings. Roofs covered with slates or shingles should have a pitch of not less than one-fourth the width of span ; but the roof may be truncated if a lower pitch is required. Allowance for Wind and Snow. Weight of snow on horizontal surface . = say, 15-5 Ibs. per sq. ft. Wind pressure on surface at right angles to line of impact = 24*6 Do. do. in specially exposed positions = 31'0 ,, D. K. Clark. Laths for Queens and slates should be 12 inches apart. Duchess and Princesses 10 Countesses 8i , Provide for removing Rainfall per Hour. From roofs ... .5 inches in depth. Flagged surface ... 2 Gravelled . . . . 0-5 Meadows, or grass plots . . 0'2 Paved surfaces . . .1 Rainfall, maximum, may be taken as 1J inches in 21 hours in cal- culating size of rain-water pipes. SLATES. Sizes. Squares covered by 1000. Weight per 1000. Weight per square. Doubles 13 in. X 6 in. 2 15 cwts. 7i cwts. Ladies . . 16 X 8 4i 25 51 Countesses . 20 X 10 7 40 5f Duchesses . 24 X 12 10 60 6 To test slates, place on edge half immersed in water for 12 hours ; if water has spread up to near the top of slate, reject it ; if not risen more than \ inch, may be considered non-absorbent. Or weigh a slate before and after immersion, and the difference will show quantity of water absorbed ; should not be more than ^th part of weight of slate. Good slates should be compact, with a metallic ring when struck, the edge not friable, incapable of absorbing or retaining much moisture hard and rough to the touch. Weight of Zinc Slating Nails. 1 inch go about 340 to the pound. H 290 H 220 if o 2 90 80 GAS iiSGlNEER'S POCKET-BOOK. Curved roofs of 25 to 30 feet span, rise span may be used if 10 B.W.Gr. corrugated iron sheets, rivetted together with tie rods every few feet, continuous angle iron skewbacks, and thin rods from the centre, to prevent sagging in tie rods. Use two nails to fasten each slate, say 1J inch long, of copper. Lowest coarse of laths for slates should be 1 inch higher than the o there. Fall in gutters should be 1 in 50 at least. Thick asphalted or inodorous felt is made in rolls 25 yards long by 32 inches wide. Sheathing felt is made in sheets 32 inches X 20 inches. Dryhair ., , 34 X 20 No. 0, 12 oz. per sheet. No. 3, 2 Ibs. per sheet. No. 1, 1 Ib. No. 4, 2i No. 2, H Ibs. No. 5, 3 Willesden roofing is supplied in rolls of 50 and 100 yards X 27 inches wide (in two qualities), or 54 inches wide if required. Allport's patent wire-wove waterproof roofing, a strong covering material made upon japanned or tinned steel wire gauze, is made in sheets 40 in. X 28 in., 42 in. X 26 in., 49 in. X 26 in. ; a lighter quality is made in sheets 42 in. x 26 in. In laying lead, where possible avoid soldered joints. Use not more than 10 feet sheets, and then fix roll. Lay to a slope of not less than 1 inch in 10 feet. Weight and Thickness of Sheet Lead. Weight in Ibs. per square foot. Thickness in inches. Weight in Ibs. per square foot. Thickness in inches. 1 017 7 118 2 034 8 135 3 051 9 152 4 068 10 169 5 085 11 186 6 101 12 -203 Usual Thickness of Sheet Lead in use. For aprons, 5 Ibs. per square foot ; for roofs, flats, gutters, &c., 7 to & Ibs. ; for hips and ridges, 6 to 8 Ibs. Proper Proportion of Tread to Riser on Staircase, projection of Nosing not included. Width of tread 12 inches, rise should be 5 inches. 11 io 2 I) 6 6* 6* 6| PROPORTIONS OF TREADS AND RISERS. 81 Another method is to multiply the tread by the riser, both in inches, and the sums should equal 72. Another rule Width of tread 6 inches, height of risers 8J inches. ? 10 11 12 18 A further method of obtaining the Proportion of Stair Treads and Risers 1*" IS" fc" 6' Thus 9-inch tread requires 7-inch risers. Stone steps upheld both ends should have 6-inch bearing at each end. one end only should have 9 inches built into wall. Timber. Timber should never be so enclosed in a building that the air cannot circulate around it, or it will decompose. When timber has to be fixed near the ground, or in any damp place, it may be coated with a thin solution of coal tar and fish oil mixed with finely powdered clinkers from the forge. All timber should be thoroughly seasoned before any preservative is used. One method of preserving timber is to dry it and apply a weak solution of corrosive sublimate, or of nitric acid and water, and then paint it with white lead and oil. Another method is to soak the timber for from 2 to 12 hours in melted napthalene at a temperature of about 200 F. The timber used in building operations for carpenter's work is imported from Memel, Riga, Dantzic and Sweden ; and that for joiner's work from Christiania, Stockholm, Gefle, Onega and other northern ports. In selecting timber the most convenient sizes are 12 inches square ; G.E. a 82 GAS ENGINEER !? POCKET-BOOK. choose the brightest in colour, where the strong red grain appears to rise to the surface ; avoid spongy hearts, porous grain, and dead knots. (La-xton.} (1) Seasoned timber is about twice as strong as green timber ; (2) well seasoned timber loses some of its strength when moisture is re-absorbed ; (3) when free from knots and flaws timber in large pieces is as strong, per inch section, as when in smaller pieces ; (4) knots weaken timber as greatly whether it is for use as a strut or as a tie ; (5) long leafed pine is as strong as average oak ; (6) bleeding a tree does not impair the quality of its timber. Timber joists should, where possible, be left open to the atmosphere at the ends, and not built into the wall. Iron joists should have a space at the ends to allow of expansion, and should be built in pockets. Planks are 11 inches wide ; deals. 9 inches ; and battens. 7 inches. Loads on Floors. Floors of factories, workshops, and warehouses should be able to carry a load of 2 cwt. per square foot. Floors of large buildings such as public buildings, lecture halls, churches, and chapels, should be able to carry a load of 1 cwt. per square foot. Floors of dwelling- houses need only be strong enough to carry a load of 120 to 140 Ibs. per square foot. Basement floor joists should rest on sleepers, which should not be laid on stone. (U.S. Assoc. of Superdts. of Bridges and Buildings.) In Tension. In Compression. Shearing. With Grain. Across. With Grain. Across. With Grain. Across. White Oak l,0001bs. 200 Ibs. 900 Ibs. 500 Ibs. 200 Ibs. 1,000 Ibs. Pine 700 50 700 200 100 ., 500 Red 900 50 800 200 Norway 800 800 200 Cedar . . 800 ,. 800 200 ., 400 Chestnut . 900 1,000 250 150 .. 4,00 All per square inch safe stresses. To calculate dead distributed safe load on timber (rectangular section floor joists, &c.) 1,100, if fir 4 ft x (P x 1.900, if oak = load in Ibs. b = breadth in inches. d = depth ., ,. L = span (R. A. Rule.) A crowd of men closely packed = 120 Ibs. per square foot. A cart horse =14 cwt. STRENGTH OF TIMBER. 83 Strength of Timber. (Ranldne's " Civil Engineering.") Wood. Resistance to Shearing per Square Inch in Ibs. Along the Fibres. Across the Fibres. Oak Ash and elm . Spruce or white fir . Red pine 2,300 1,400 600 500 to 800 4,000 Wood. Weight required to crush 1 Square Inch in the direction of the Fibres. Weight required to indent 1 Square Inch 2\j inch deep across the Grain. Ash Fir (white) Fir (yellow) Oak Pine Cwt. 80 50 52 80J 36 Cwt. 12i 5 5J 18 H Wood. Weight required to break a Stick 1 Inch Square by Tensile Stress. Ash Tons. 41 Fir (white) Fir (yellow) ... Oak Pine H P 1 Time required for Seasoning. (Laslett.) Pieces 24 inches and upward square require about Pieces under 24 inches to 20 20 16 Oak. Months. , 26 22 18 14 10 6 Fir. Months. 13 11 9 7 5 3 G2 84 GAS ENGINEER'S POCKET-BOOK. Breaking Load in Tons on Square Yellow Pine Pillars, firmly fixed and equally loaded. 6 7 8 91011 12 I I li. 77 / 1 i 1 4 2 / 1 1 Z t i i / j- I / 1 i 1 -1 L / / 1 i 5 , / 1 / / I I / / / /.., 1 / / / I 1 / // L ^ / 1 / 7 1_ / /"/"i 1 1 / / 1 / / 71 L ./ / / lJ_j j. j 1 / / / / 1 1 T / j / / i If II /. (J. j / 1 IIIIZ:? ' / / / 7 / / i 1 ///? A/ '-jJ-L // / / / / /// i / i 1 / / <, / J-L 1 77, / y { ////, // LLfl v 7 : 1 / , / y L Af/ / . / / 7vZ HH- 1 7 j. i / / / / / Z22 22 7 Z Z / / / / r / / / ({tit V / 7 / / / ' / / ) / / , / v / / / / / 7 / / ' // / W''// ty L! / / // J-'J-t/i -y '2 / l ^777/ / / / t / ^ // / // / /// ' 2 ' 7 LLjj.'I. / / / / ! 2Z z 7 ////// / / / 7 , 4 t_/_ / / > /// // y/ / / 2 [2] J2ZJZ!, / ' y / / '. y// -- f / ^ // r ./ 7 Z ///, ^ C > ^ x / / 2 / / / ' V / V 7 7 / /7 /7 y // x x / / / 77 7 '//'//////'/ / / 7 7 , 7/2 A/A/2//2zZ / / / 7 ^/ ^ T^ : / ' ^ 2 / f / / ^ \ ^ / / / /y/ifafr ^ z2 Z (1^1 ^ / / f -, ^ 5? about from (heavy) (heavy) 150 86 120 14 8 10 6^ 1 to 2 65 90 4 Ibs. j ?5 cwt. )J 5 Ibs. ;> tons. Theoretical H.P. of falling water = '00189 Q.H. Q = volume in cubic feet of water flowing per minute. H = fall of water in feet. GAS ENGINEER'S POCKET BOOK. Power of water fall (theoretically) : Gallons per minute x lOlbs. x height of fall in feet 33,000 = H.P. Head of water in feet x '434 = Ibs. per square inch. Velocity of water in a uniform diameter cast iron pipe of smooth bore = 48 A f< f + * dieter in feet. length in feet (Hawksley.) Quantity of water discharged from a channel or pipe = 100 sectional area of / head in feet current in square feet V length in feet x h y draulic mean de P th - (Downing.) Frictional Loss in Hydraulic Bams. (" Hicks' Formula.") F = -04 P D P = total load in Ibs. D diameter in inches. F = frictional resistance in Ibs. 1 inch mercury = 13*4 inches water = 345'4 millimetres. 3^&ths inch mercury = 12 inches water. 1 gallon salt water = 10-272 Ibs. 1 ton =35 cubic feet =218 gallons. Specific Heat. Specific heat = proportion of heat required to heat a substance through 1 degree compared with equal weight of water. Specific heat of water = 1. Specific Heats. Brickwork Chalk .... Charcoal . Coal (anthracite) . (bituminous) . Coke 192 215 241 201 241 203 Glass Graphite Ice . Stonework . Wood average . . -190 . -202 . -504 . -197 . -550 Speed of Sound. In air at = 1.093 feet per second. Add 2 feet for every degree Centigrade. In water = 4,780 feet per second. In copper = 11,666 In iron = 16,822 RADIANT HEAT. 89 Comparative Powers of Substances for Reflecting Kadiant Heat. Polished brass Silver . Tin . Steel 100 90 80 60 Lead . Glass Lampblack . (50 10 Table of Coefficients of Linear Expansion for 1 Degree Centigrade Glass Platinum Cast iron Wrought iron Copper Lead Zinc Brass 0000085 0000085 00001 000012 000017 000028 00003 000019 12OOOO Tooooo 85000 58000 35000 34000 52000 Specimens vary in their expansions, and the above Table is only approximate. Factors of Safety. (Umvin.) Live Load. In Structures Dead Load. Temporary Structures. Permanent Structures. subjected to Shocks. Wrought iron and steel 8 4 4 to 5 10 Cast iron . . . r> 4 f> 10 Timber 4 10 Brickwork . . . 6 Masonry 20 20 to 30 One B.T. unit oi electricity = 1,000 watts for 1 hour. One H.P. = 746 watts. One B.T. unit of electricity = li HP. very nearly. Sizes of Wire Gauges in Decimals of an Inch. Size. Birmingham Wire Gauge. Imperial Standard Gauge. Size. Birmingham Wire Gauge. Imperial Standard Gauge. 1 312 300 13 093 092 2 281 276 14 078 080 3 265 252 15 070 072 4 234 232 16 062 064 5 218 212 17 054 056 6 203 192 18 046 048 7 187 176 19 042 040 8 171 160 20 038 036 9 156 144 21 034 032 10 no 128 22 031 028 11 125 116 23 028 024 12 109 104 24 025 022 90 GAS ENGINEER'S POCKET-BOOK in vdiy ao ic a ocot-oeoi>-ocot~ocot-oiot- civTHT-iarr HOaO?OiO:C--cOGOCCO^OCO?riCCO'-< -* 1C 1C O t^ CO O5 O O rH (N CO -*l >C 1C ^S t^ CO C5 CSOi-li-lO'MOOiCiOCCt^QOO III 1?9JV J0 ^99.1 oiquo ^OOjI V JO S[BIU109(J It .I9^9UIT?ia co o co o t- O5 I-H cc 10 i> o i i cc c^ o o; i^- >c cc c-i O O i I SC "-- '-C C^l t- - C 1C ?O t~- GO CV ea W ^* * *e o 3? P t t- oo O C -^ o ao O CJ OOOOOOOOOOOOO.-(i-ii-ii-Hi-i(M(M WEIGHT OF ONE LINEAL FOOT OF FLAT ROLLED IRON. 91 t^ i- t~ 00 00 00 ;iO T* T* Tj< (N rH rH O OS CO ^- rH gSSig I- 1- OO CO oo Ci OI O> O O O rH O O 10 CO O 0 00 r O i- 00 O rH (M , ^ 00 rH 1C 00 rH i- i- 00 CO OO OI Ci Oi i&?999 OJ^t^i-00000000 'T^vO-^iC^OO OCOCOOOO' lO rH 1^ CO Oi *O i 1 1^ r- ^- 1- i~ so 007HCOipGCOCqp I- . r- iO * 00 O 00 1- "O CO CO O O rH n o oo (M (M CO (M (M 1 O OrHCO'ti^OOCiCCi ^C >O i CO p co rH o c; co i c>i t~ r-H CO 1O t- O r-l , rH I-COOiOr-li-CO' I16ISHI 3* 2 II _ HM . CO a+ c -5 92 GAS ENGINEER'S POCKET-BOOK. O 1- 1- t-- CO CO Cl SrHrn'rHrHrHrn'rH 3 S rH 2 rt *~ *~ ^ CO Cr. cV. Ci < OrHrHrHCMCMCMCO CO CO -t -*<*< o >O v-O O 5O ',O 1- h- !- CO CO C~. *M O rH ITJ CO rH Cl ^2 01 7^ -p 9 CN S ID CO OrHfN^ifflSOb-Cl CO -p OJ 0 >O 'O 1- CO CO b- OS rH CO I OOCOCOCOOCiCi ig CO (O CO O a o <> o to o o t- c " o i o c CN-^ri /- i- t- t - CO CO GO 00 O -M -t 1- O CO CO ^ add 9'1 run of L or T = 5J, tlien 5J O CO * O 'O to 1~ 1- t- O ^O rH O CM CO CO Oi -pOCOOi rHCN^O t- t- 1- 1- CO CO CO CO ooo lOCOrH-^l^OCOO Cl CO O O t~ CS O i- o i o i i i> i- r- ^ CO CO t^ rH 1C Oi rH 0-1 CO ^ O t- 00 < -* M rH 1~ O CO f-H Oi '. .. t.- CO CO CN) CM CM CO sllls he wei L iron j Oco X WEIGHT OF ONE LINEAL FOOT OF FLAT ROLLED IRON. 93 sal COl'-rHiOO^CO'N

7-1 "p O ip O> ^T^^C^SciC-lcfl CM CN O co coOiCO^>pcob-o coj>>pco^cpcot IO5O5O5OOrHrH r-lr-IC-llNCOCOCO-* 4(<4tl>oiboig OCoSojiNipOOrH ipOO^HTtl (N IN O O O rH rH rH S5 OS 01 OOOOCOOrH ^-HrHrHr-KNfNO-l rHO'OOOOlOlO COl^ t- t- jf- Jt- t- !- 00 00 00 00 CO CO CO 00 O3 OS co co -f * in >c m o COOlOrHC-lCO^O Ot-COC; OrHCN o m to '.o -o 5 5 --0 o t- r- 1- m c-i co co -p ;* o co o 01 t- uo co rH cr. i^ 10 co rn si i~ >n co I-H c-icNcocococoeoco eocococococococo 13 a * D 73 H Si i! H>< S* _J s if O-*i :i .s-v, & X o|, Sa 94 GAS ENGINEER'S POCKET-BOOK. "'" ' '"'" ' 18 338 ?ggS 'O O O -* 71 , ' rH OCOOCOOCOlOOOO* 1- rH O Oi CO 1 - rH >O ~ l~ X O rH 71 CO lO 00 ^ *? -t -t- i* > . 00 00 00 OS OS OS O O O 1-1 rH rH 71 I 71 71 71 71 71 71COCOCOCOCOCOCO 71 CO CO CO -^ *# -rj< rt< O C O '-C "C *C I' 71 71 71 71 71 71 71 71 71 71 7-1 71 71 71 71 71 (71 ip t- O CO -p OS 71 >p 1- O CO p OS 71 O 00 rH T? OrHrHrH,lH71jl7-l CICOCOCOCO^'^'^' O^-CT. rHO-;iOt-C3rHMIit- sg (71 71 71 71 71 71 71 71 71 71 94 O4 8 CQ -o i- r- - 1~ j OrHCOOOOOOrHCOiO'-OCO T1-M7I71717ICOCOCOCOCOCO 1-7 I - ". ^- 7C ?: 'C X 1 O 71 "* O 1^ ^. rH CO O C^ ^t X ?7; T' 7'l I - rH -,C O >O 71 71 71 71 CO CO CO CO CO CO * -^ h X -C Oi 71 lO t^ rH rf J- O O CO CO 1- rH iO Oi -t 00 rf O 1^ GO CS rH 71 CO ^ "^ i~ "-C I - I~ Jt^- 00 OC iGOOOCOOS OSOSOSOSOSOSOSOS OOt-<71CO"*j~->O;p7t7it~oo co-*7 1 oto;o-t7i ocoiocoocooooocoioa ^0 O ^C 'O *-O '^) "-O '^ "^ t^. I>- t t^- t- l>- f~ OO OO Ci O O rH rH 71 CO CO ^ >OSOCOiOl-~OSrH COOCOOrH-^-OCO o I 71 71 CO CO -^ -? O O : ~ -C t - l~~ -> X> OS .Tfcp7l-ppipCi CO^-rH>p 1^,^^^,^,^,^, Jj.^^^^,^-^-* "iO>O->t~t~I^OOOOOSCS O 71 CO * OS O rH CO * O O 71 CO -t O )7H SSS7l?^S ftSScop^:? 1 -; S^os-S: 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 71 Ir 4^ WEIGHT OF ONE LINEAL FOOT OF FLAT ROLLED IRON. * H5 O CO to O CO '-O O CO to O CO to O 55 S3 S 35 * jjjjj <* 5 55 g OOliOCOOCOiOCCOCOOCO OCOCO 00 O COOCOOCOiOCOO 3 rH CN CO O p 1- CO p rH "M CO O O 1~ CO O rH Ol TQ O p t~ CO O O G". CO i~- p *O O ^ CO O} rH i O Ol O CO rH 4t< l~ O CO i> Cs 01 O Jr- O CO O Oi Ol >b CO rH 4j< /- O t-t-l-t~OOCOC0010iOiCiO pprHrHrHrHOlOlOlCOCOCOT?! 5O-o2S^t^GOCOCO^ 8' iO 'O to tO tO 1 I 1~ I>- GO CO CC' CO CO C7. 'C7. C7- C7. O O O O rH )l^-iO^O1OCit OCOO3 OCOt^OCOOlOOitO>CCOOlO Jr-HOlCO^lpOp^-GOp p O rH Ol CO -^ lO p p t~ 'O) CT. O i O 01 -t tO 00 O Ol iO t~ O> rH i to -O to to to 1- i- 1- t- - CO CO CO CO CO Oi C: C51 O ?h-iOCOOCOiOCOOCOOCO OCOOCOOCOOCOOOOiOCOO CO 1- p O CO 01 rH O CO I- p O CO 01 rH O CO t~ p O CO Ol rH O St^-COOt tocoo rHCOiOtOCO OrHCOiOtO OiOOiOiO otOtOtOtO ODOrHCOlOO >io oiooooopioojrtoioo i 1 (M 00 iO 1~ CO O i-H OOrHOlCOTfiOiOOl^COOi OOrHC-lCO^^iOtO^-ClOCiO Ol Ol Ol Ol Ol Ol Ol Ol 71 Ol CM Ol CO CO CO CO CO CO CO CO CO CO CO CO ^tt p ^ 00 01 p p ip p CO ^- rH ip p 4f OO 01 p p p p CO 1- rH --O O OOOrHrHO10101COcV54t J cylinders, large . . -094 = ?> small . -06 = JL Brass . -17 Lead . i . -31 Zinc . 25 _ 4- Copper . '17 _ 4 Tin . 25 16 Bismuth , -154 z i Babbitt Metal. Proportions of Babbitt metal for running in cast iron boxes 1. For light work . . .50 tin, 5 antimony, 1 copper. 2. heavy . . . 46 8 ,, 4 .. Attrition Metal. One copper, 3 best tin, 2 regulus of antimony ; heat separately and then mix and add 3 more parts tin ; on remelting add twice the quantity of tin to one of above mixture. Delta Metal. Cast, Copper, 55-94 per cent. ; zinc, 41 -61 per cent. ; iron, '81 per cent. ; manganese, -81 per cent. ; lead, '72 per cent. ; phosphorus, 013 per cent. ; nickel, a trace. Wrought. Copper, 55-8 per cent. ; zinc, 40-07 per cent. ; lead, 1-82 per cent. ; iron, 1'28 per cent. ; manganese, '96 per cent. ; phosphorus, -Oil per cent. ; nickel, a trace. Boiled. Copper, 55'82 per cent. ; zinc, 41-41 per cent. ; manganese, 1-38 per cent. ; iron, -86 per cent. ; lead, -76 per cent. ; nickel, '06 per cent. ; phosphorus, a trace. Hot-punched Metal. Copper, 54-22 per cent. ; zinc, 42-25 per cent.; lead, 1-1 per cent. ; manganese, 1'09 per cent. ; iron, -99 per cent. ; nickel, -16 per cent. ; phosphorus, '02 per cent. Tensile strength of cast = 35 tons per square inch. forged = 42 Will not weld, but can be soldered. H2 100 GAS ENGINEER'S POCKET-BOOK. To Case harden. Make the surface bright, heat to red heat, rub with prussiate of potash, and quench in water. Or, better, heat the iron in a close box filled with bone dust and cuttings of horn and leather. (Unwin.) Colours and Temperatures for Hardening Tools. Pale straw = 430F. for lancets, &c. Dark yellow = 470F. razors. straw = 470F. penknives. Clay yellow = 490F. chisels and shears. Brown = 500F. adzes and plane irons. Very pale purple = 520F. ., table knives. Light purple = 530F. ., swords and watch springs. Dark = 550F. ., softer swords and watch springs. blue = 570F. small fine saws. Blue = 590F. ., large saws. Pale blue = 610F. saws, the teeth of which are set with pliers. Greenish blue = 630F. very soft temper. To unite two pieces of lead, the surfaces to be joined are scraped bright, and between them there is immediately inserted a very thin leaf of lead amalgam that is, lead-foil that has been saturated with mercury. On passing a soldering iron along the seam, or by heating in some other way, the mercury is vaporised and driven off. The lead is left free in an extremely fine state of division, and in that state readily fuses, and forms a sound joint between the adjacent parts. STRENGTHS AND MODULUS OF ELASTICITY. 101 1 1 I 1 1 I I 1 1 I I 1 1 1 1 1 1 I III III I g" I g" I 8"S I s bo 3 1 1 1 3 1 1 r 3 1 3 1 3 1 333 1 3 1 1 3- 1 i i i i i 4 > )> * U -0-9 (W.I.G.) Diameter of Rivets for Plates of Different Thicknesses. Thickness of Plates = t. Diameter of Rivets = d. Diar. of Rivets after Riveting = r04d. Inches. Inches. i 0-60 A 0-624 t 0-67 p 0-72 0-73 0-78 1 0-79 H 0-85 0-85 1 0-91 T5 0-90 l 0-91 0-95 tf 0-97 I f 1-04 1-12 it 1-10 1-17 1 1-20 14 1-24 Resistance to Shearing. When rivets fit the holes exactly, shearing stress = P area of cross-section. If the section is rectangular, and pressure perpendicular to one 3 H side, = ^- If the section is circular or elliptical, and pressure perpendicular 4- P to one side, = _ 3 a If the section is square, and pressure acts parallel to a diagonal, = ^. 8 a STRENGTH OF RIVETED JOINTS. 107 Resistance to Torsion. 12 x 33,000 x HP. Twisting moment = 2 ir N Resistance to twisting = Shearing stress x Z^ Z, for cylindrical bars = 0*196 d 3 b Z, , hollow do. do. = 0-196 d ^~ d ^ t di Z t square bars = 0-208 side 3 Average Proportions of Rivets to Diameter of Hole. The shearing resistance of steel rivets is little greater than of rivet iron, owing to its necessary soft quality. Small rivets for plates less than f inch thick may be riveted cold. Strength of Riveted Joints to Plates. Joint. Riveting. Cover Straps. Pitch of Rivets. Diameters. Strength of Joint to Plate. Lap Butt Lap Butt Single )> Double 1 2 1 2 3d 3d 5-5<2 55 55 57 69 69 72 Shearing resistance of iron or steel bars = |ths their tenacity. Rivet iron, shearing resistance, in Ibs., per square inch 49,(>00 steel 52,800 Values of Riveted Joints and Apparent Tenacity in Lbs. per Square Inch. Iron Plates. Steel Plates. Plates Steel Plates. Single riveted, drilled . punched Double ., drilled . .. punched Treble drilled . 0-88 0-77 0-95 0-85 1-00 0-90 1-06 1-00 1-08 40,500 35,400 43,700 39,000 45,000 62,000 55,800 65,700 62,000 67,000 lakmg iron at 46,000 Ibs. per square inch, and steel at 62,000 Ibs. 108 GAS ENGINEER'S POCKET-BOOK. Apparent Shearing Resistance of Rivets in Riveted Joints. (Unwin.) Iron rivets in punched holes . . . 46,000 Ibs. per square inch. drilled ., ... 43,000 ., Steel punched ., ... 53,000 drilled ... 49,000 ' Proportions of Rivets. The height of a finished snap-head should be from fths to fths the diameter of shank. Allowance in length necessary for this = 1| times the diameter ; in machine riveting add |th to th more. Allowance for countersunk riveting = diameter of shank. Strength of double riveted joint = 70 per cent. single = 56 (Herring.) Diameter of rivets in plates under inch thick should be twice the thickness of the plate. Diameter of rivets in plates above inch thick should be 1^ times the thickness of the plate. Proportion' of rivets to thickness of plate diameter = 1-2 *J thickness of plate. (Unwin.) Advantage of machine riveting is that the rivet is still hot when the head is finished. Pressure on rivets by machine = about 25 tons. Holes in iron should be punched, and afterward drilled out |th inch larger to prevent starring and damage to the surrounding metal, or drilled full size in all girder work. Kivets are not considered reliable in tension. The best way with steel plates is to anneal them after punching if of inch to f inch thickness, or the holes rimered after punching. Above this thickness all plates should be drilled. The sharp square edge of a drilled hole is not likely to add any strength to the rivet, but rather the reverse. If the plates through which a rivet is to be passed are more than 6 inches in all it is distinctly better to use bolts. The old plan of driving a conical drift into the rivet holes is an objectionable method of ensuring agreement, as it injures the plates, but if the holes are rimered when in position the punched hole is improved in strength. With very soft, ductile plates, it is believed that the injury done in punching is comparatively small if the punch be sharp. But with rigid plates the injury is apparently serious, the plates being weakened 15 per cent, to 30 per cent. (Unwin.) To fill up the hole and form a head, from 1'3 to T7 times the diameter should be allowed in ordinary riveting, and about three- fourths the diameter if countersunk rivets are to be used. Machine riveted work is slightly stronger than hand work. STRENGTH OF ROPES AND CHAIKS. 109 "S O C3 HN ;p ^ 1 oicco^^o^^o | gS -If -If - ?l C^l CO "^ CO GO O "5 lO GO "^ O lO O i irHrHi IC^CO-^^O IN rH rH rH w 410 03 coj^ji ^ ^ic^ rH(NiOQO(NOCOC5 rH rH rH (N (N CO CO 1 S sjf* j Igs rH rH C^ C^l CO "^ U5 tr^ QO O^ C^l 1C rH rH ill rH rH rH rH C^ C^ C^ C^ CO CO CO "HH ''H II rr:fc^liIM w 1 tSli l5JH _g -*) -* HN HN rH rH C^ C^ CO CO ^H ^ *O ^O b* GO Oi 110 GAS ENGINEER'S POCKET-BOOK. Strength and Weight of Hemp and Wire Bopes. TARRED ITALIAN HEMP. HAWSER LAID. WIRE ROPE. HAWSER LAID. Circum- ference. B. W. Weight of One Fathom. Iron B. W. Steel B. W. Weight of One Fathom. Inches. Tons. Lbs. Tons. Tons. Lbs. i 11 15 I 17 221 1 30 3 1-0 94 H 89 43 1-35 1-5 li 94 57 2-15 6-25 2-5 2 1-44 93 4-0 11-2 3-5 2i 5-0 4-5 8 2'16 1-5 6-0 19-5 5-75 2f 7-73 6-5 3 3-0 2-02 9-2 24-5 7-5 3 i __ 10-93 27-5 8-5 s* 4-2 2-9 12-5 45-0 10-75 5-6 3-8 15-75 54-5 13-25 4* 6-75 4-7 21-0 66-87 17-75 5 8-0 6-0 24-8 21-5 5J 11-0 7-1 30-0 83-0 26-5 6 14-25 8-5 36-2 100-0 31-5 6* 16-1 10-0 42-75 40-6 20-6 11-7 48-35 42-5 7| 21-75 13-3 55-0 46-75 8 25-75 15-0 59-0 51-75 8J 28-0 17-0 65-33 58-42 9 30-5 19-0 w 33-75 21-3 10 36-0 23-6 10i 38-9 26-0 11 42-0 28-5 11* 45-1 30-0 12 48-5 34-0 STRENGTH OF ROPES AND CHAINS. Round Ropes of Iron and Steel Wire. (R. A. Rule.) Ill \v , ; i f IRON WIRE. STEEL WIRE. Circum- ference in Inches. weignt per Fathom in Ibs. , Safe Load in Breaking Load in Safe Load in Breaking Load in Tons. Tons. Tons. Tons. 1 1 0-33 i-o 0-83 2-5 li 1-5 0-58 1-75 1-25 3-75 4 2 0-7 2-1 2' 6 2 4 1-25 3-75 3;33 10 2* 6 1-86 5-6 5-33 16 3 8 2-95 8-85 8- 24 3* 11-5 3-88 11-65 10-66 32 4 15-5 4-92 14-75 13-33 40 *i 19 6-55 19-65 17- 51 5 23 7-73 23-2 21- 63 5i 28 9-36 28-1 25-33 76 6 34 11-32 33-95 30-. 90 6J 40 13-3 40-0 35-33 106 7 46 15-1 45-3 41 123 Steel wire ropes are usually made from f to g inch diameter, but can be had up to 3 inches diameter. When made with a hempen core they are more pliable, and for that reason more generally adopted for the purpose of transmitting power, when the wire rope takes the place of the leather straps which are more usually employed. One advantage of the use of rope gearing is the greater distance over which the power can be transmitted. In testing steel cables, the result will only equal about 75 per cent, of the aggregate strength of the individual wires. Safe working strain in tons of iron chains = (diameter in eighths of inches) 8 10 Weight in Ibs. per fathom of iron chain = (diameter in eighths of inches) 2 Safe working strains in tons of rope = circumference' Weight in Ibs. per fathom of tarred rope = White rope is about ^ lighter. 8 circumference* Safe Working Loads in Iron Chains. Diameter, inch Load. Tons. Cwts. 14 16 10 Diameter. 1 inch 7 Load. Tons. Cwts. I) 11 13 112 GAS ENGINEER'S POCKET-BOOK. Approximate Strength of Chains. The square of the diameter in eighths = the weight of chain in Ibs. per fathom. The square of the diameter in eighths divided by 2 = breaking weight in tons. Safe load = J. (F. Rogers.) Temperature of iron when welding. 1,500 to 1,600 F. Strains in Ropes round Pulleys. (R. A. Tests.) Two treble blocks used. Weight lifted = 59 cwt. 109 Ibs. Position where Strain is taken. Strain. Holding after Lowering. Raising. Lowering. Free End. 15-37 5-91 6-62 1st return 2nd 3rd 4th 5th 6th 13-28 12-0 10-67 9-7 8-7 6-105 7-10 8-42 9-42 10-56 12-28 13-56 7-84 8-84 9-60 10-56 11-77 12-0 Total, excluding free end 60-45 61-34 60-61 The free end has no share in supporting the weight. When a weight is being raised, the strain on the running end is greatest, the sum of all the friction being at that end, and on the standing end least. When the weight is being lowered the reverse is the case. Safe Working Loads on Hemp Hopes. Circumference. Load. * Circumference. Load. 1 inch = If cwt. 5* inches = 2 tons 14 cw li = 4 6 = 3 4 2 = 7 H = 3 IBi 2i ,, = 11 ,, 7 = 4 ?i 3 ,, - 16 ft = 5 Si - 21 8 = 5 14 4 = 28* 8* = 6 7 4* = 36 9 = 7 1 5 = 44* Testing Iron and Steel, If a fracture of iron gives long, silky fibres of a leaden grey hue, the fibres cohering and twisting together TESTING IRON. 113 before breaking, it may be considered a tough soft iron. A medium, even grain mixed with fibres is a good sign. A short blackish fibre indicates badly-refined iron. A very fine grain denotes a hard, steely iron, apt to be cold-short and hard to work with a file. Coarse grain, with brilliant crystallised fracture, and yellow or brown spots, denotes a brittle iron, cold-short, working easily when heated. This iron welds easily. Cracks on the edge of bars are a sign of hot-short iron. Good iron is readily heated soft under the hammer, and throws out but few sparks. Nitric acid will produce a black spot on steel ; the darker the spot the harder the steel. Iron, on the contrary, remains bright if touched with nitric acid. Good steel in its soft state has a curved fracture and a uniform grey lustre ; in its hard state, a dull, silvery, uniform white. Cracks, thread, or sparkling particles denote bad quality. Good steel will not bear a white heat without falling to pieces, and will crumble under the hammer at a bright red heat, while at a middling heat it may be drawn out under the hammer to a fine point. (" Journal of Gas Lighting.") Contraction at point of fracture should be about 10 per cent, for plates, 15 per cent, for T and L iron, and 20 per cent, for round or square bars. (Kirkaldy.) Iron or steel subjected to stresses above half their ultimate strength are permanently disabled. Breaking strength equals 39 (1 + C. 2 ) tons per square inch (C. = per cent, of carbon). (Bauschinger.) In calculating the weight of metals up to 100 C., the temperature can be omitted as the difference is so small (USQO). An iron rod one square inch in section exerts a force of one ton by contraction in decreasing in temperature 9 C. Wrought iron increases 10 fr 00 of its length for every ton per square inch of tension up to the limit of elasticity. (Unwin.) The expansion due to a tension of one ton per square inch is pro- duced by a rise in temperature of from 12 to 15 F., according to the quality of the iron. Wrought iron expands by heat f^th more than cast iron, while tension causes twice as much stretch in cast iron as in wrought iron when within the elastic limit. 27 F. increase or decrease of temperature causes an expansion or contraction, equals a stress of one ton per square inch, if the metal be fixed at each end. Strength of wrought iron and steel increases with a rise of temperature up to about 500 F., beyond which point the metals become plastic and will flow under almost any strain. (Professor 11. C. Carpenter.) The tensile strength of steel diminishes as the temperature increases from zero until a maximum is reached between 200 and 300 F. ; the total decrease being about 4,000 Ibs. per square inch in the softer steels, and from 6,000 Ibs. to 8,000 Ibs. in steels of over 80,000 Ibs. tensile strength. From this minimum the strength increases up to 400 to 650 F. ; the maximum being reached earlier in the harder steels, and the increase amounting to from 10,000 Ibs. to 20,000 Ibs. per square inch above the minimum strength at from 200 to 300 F. (J. E. Howard.) GE. T 114 GAS ENGINEERS POCKET-BOOK. Effect of Temperature on the Strength of Steel and Wrought Iron. Taking the initial temperature at C., with an increase of tempera- ture of 200 C., the strength of wrought iron is reduced 5 per cent. At 300 Cent. 10 per cent. 400 27 500 62 At 600 Cent. 81 per cent. ., 800 89 1,000 96 The ratios between cast iron, wrought iron, and steel are 13'34, 10, and 10*7 respectively. Diminution of Strength of Copper hy Heat. (Franklin Institute.) Temperature above Diminution of Temperature above Diminution of 32 degrees. Strength. 32 degrees. Strength. Degrees. Degrees. 90 0-0175 660 0-3425 180 0-0540 769 0'4389 270 0-0926 812 0-4944 360 0-1513 880 0-5581 450 0-2046 984 0-6691 460 0-2133 1000 0-6741 513 0-2446 1200 0-8861 529 0-2558 1300 1-0000 Weight of Cast Iron Pipes. (See also page 286.) In Ibs. per lineal foot. The weight of two flanges or one socket may be reckoned weight of 1 foot : THICKNESS OF METAL. t a t { 1 1 1| H Inches. 2 8-7 12-3 16-1 3 12-4 17-1 22-2 4 16-1 22-1 28-3 5 19-8 26-9 34-4 42-3 6 2B-4 31-9 40-6 49-7 7 27-1 36-8 46-7 56-8 8 30-8 41-6 52-8 64-3 9 34-4 46-0 58-9 71-7 10 fl-4 65-1 79-0 93-3 CAST IRON PIPES. 115 Weight of Cast Iron Pipes (continued'). In Ibs. per lineal foot. The weight of two flanges or one socket may be reckoned weight of 1 foot : THICKNESS OF METAL. Bore 1 i 1 1 i l H li Inches. 11 56-4 71-0 86-4 101-8 12 77-3 93-7 110-4 127-4 14 89-6 108-4 127-5 147-0 15 115-7 136-1 156-8 16 123-1 144-7 166-6 18 137-9 161-8 186-2 20 178-9 205-8 260-3 22 225-4 284-8 24 245-0 309-3 All cast iron pipes above 6 inches diameter should be cast on end, spigot up, and about 4 or 6 inches cut off afterwards in a lathe to remove the spongy portion. Eule for the Weight of Pipes. (Molesworth.) D = outside diameter of pipes in inches. d = inside iv = weight of a lineal foot of pipe in Ibs. w = It, (D 2 - d a ). k = 2-45 for cast iron = 2-64 for wrought iron = 2-82 for brass = 3-03 for copper = 3'86 for lead. 116 GAS ENGINEER'S POCKET-BOOK. Ordinary Stock Dimensions of Spigot and Faucet Connections. The thickness of Metal is in proportion to Pipes. SHORT BEND. Diameter. 2 in. 3 in. 4 in. 5 in. 6 in. Tin. Sin. 9 in. 10 in. 12 in. A 9 m HI 13{ 14* 1*| 18* 16} m J3 B 12 u 16 17 * 1* 1* 20U 22 221 2* R Si H 9 10 HI 11 12 13 13 13* LONG BEND. Diameter. 2 in. Sin. 4 in. 5 in. Gin. Tin. 8 in. 9 in. 10 in. 12 in. A 6* 6 T 3 7 7* 8* H 12fi 1*1 12| 14* B Hi 13 H| 17* ttf 19| 19f 21* 2| 25i B 2| H 4 *J 3 H Ie 84 Si *0i |TH BEND. Diameter. 2 in. Sin. 4 in. 5 in. 6 in. Tin. 8 in. 9 in. 10 in. 12 in. A 71 9 10* 10* 10* 10* m 13ft 16* in B 9 10| 11 lit 12ft 13* in 21 1 19 1C) II 15.} lf| WI in 17| 16ft 20| 2*| 3RJ 24J Average Weights of Connections. Internal Diameter. Tees. Collars. Syphons. Caps. Cwts. Qrs. Lbs. Cwts. Qrs. Lbs. Cwts. Qrs. Lbs. Cwts. Qrs. Lbs. 2 1 17 12 2 14 009 :? 2 11 25 2 25 1(5 4 039 015 2 1 4 21 5 1 1 1 22 4 14 1 2 6 120 020 4 1 7 1 13 7 1 3 21 2 20 4 1 25 1 21 8 2 1 21 037 427 023 9 2 3 14 ion 4 2 14 2 24 10 3 2 11 1 14 4 3 25 035 12 427 127 610 1 14 14 637 200 707 1 1 25 15 7 18 210 707 137 16 8 1 7 2 2 14 7 2 25 1 3 14 18 9 1 21 3 14 11 1 2 1 11 20 10 1 14 314 12 2 14 2 1 25 24 16 3 500 13 3 1 7 SOCKET BENDS. 117 Bend. 118 GAS ENGINEER'S POCKET-BOOK. Ordinary Stock Dimensions of Flanged Connections. D lu. H In. 2 In. 2* In. 3 In. 3i In. 4 In. H In. 5 In. 6 d 2* 2 3i 3 3| il 5 e H 5 5| 6fl F 6 6 7 H 8i 9 10 10* 12 H 9 10 11 12 12i 121 14 16* 18| R 6 5& 6 6| 11 H 10| 10 tt No. of Holes in Flange 4 4 4 4 4 4 4 4 6 Centres of Holes . . In. *i In. ** In. 6* In. 5! In. 6| In. 7 In. 8 In. 8J In. 10 D In. 1* In. 2 In. 2* In. 3 In. 3i In. 4 In. 4* In. 5 In. 6 d, n 2tt 3i 3 3^ *4 4 5| 5 6tf F 6 6i 7 n 8i 9 10 10i 12 L 81 9| 91 10* 11 HA HI 12* 12i R 15 16| H* 18i 161 16* 16i 18* 13i No. of Holes in Flange 4 4 4 4 4 4 4 4 6 Centres of Holes . . In. H In. 4| In. H In. 5! In. 6^ In. 7 In. 8 In. 8i In. 10 D In. H In. 2 In. 2i In. 3 In. 3i In. 4 In. H In. 5 In. 6 d 2* 2^ 3i 3 5 3! H *f 5f 6 6tf F 6 6 7 7^ 8* 9 10 10* 12 A 7& 7tf 9* 9^ 9 9 10 12A 12J B 7f 6J 9i [5 9i 3 5 9i 10 12* 12} No. of Holes in Flange -4 4 4 4 ^ 4 4 4 6 Centres of Holes . . In. 4i In. *f In. 6* 1 In. B| In. 64 In. 7 In. 8 In. 8* In. 10 FLANGED CONNECTIONS. 119 u - 120 GAS ENGINEER S POCKET-BOOK. Diagram showing Weight of small Cast Iron Pipes of different Diameters and Thicknesses. 1 60 xi" 2" 3" 4" 5" 6" 7" 8" 9" 10" n" 12" Bore. WEIGHT OF CAST IRON PIPES. 121 Diagram showing Weight of Cast Iron Pipes of different Diameters and Thicknesses. 20' 30 Diameters. 40" 48" 122 GAS ENGINEER'S POCKET-BOOK. Weight of Cast Iron Gas Pipes. Internal Diameter. Thick- ness of Metal. Internal Diameter. Thick- ness of Metal. Inches. Inches. Cwts. Qrs. Lbs. Inches. Inches. Cwts. Qrs. Lbs. (1 & 1 3 14 4 730 jl 1 7 15 I 8 1 2 A 1 16 16 f 910 2* 2 028 j 18 i 11 1 f 3 i 3 18 1 20 f 13 2 4 si 1 1 13 21 i 14 & 5 1 138 i ^ 22 15 rt 6 IS 2 1 15 24 9 17 2 1- 7 ft 2 3 15 30 i 26 1 8 33 3 1 24 Cs 36 i| 34 3 1 9 4 10 42 46 2 o 10 1 426 48 1_3_ 51 12 1 5 2 20 Proportions of Pipe Flanges, (Unwin.) Thickness of flange = f thickness of pipe ( = If joint is made with lead ring, thickness = 1 1 Width of flange outside pipe = twice diameter of bolt + 1 bdt Diameter of bolts = 0-01 6 diam. of pipe x Number of bolts = 2 + diameter of pipe Diameter of bolt hole = diameter of bolt + BarfFs process protects iron by forming on its surface a coating of magnetic or black oxide of iron, by subjecting the iron for some time to the action of superheated steam at a high temperature. Dr. Angus Smith's process consists of heating the iron to 310 F. and plunging it in a bath of pitch maintained at a temperature of at least 210. A little oil may be added to the pitch. Tar with a little tallow and resin forms a good coating to be applied cold. The requisites of a good paint for the preservation of iron and steel are stated by Mr. Woodruff Jones to be these : (1) It should firmly adhere to the surface and not chip or peel off; (2) It must not corrode the iron, otherwise the remedy may only aggravate the disease ; (3) It must form a surface hard enough to resist frictional influences, yet elastic enough to conform to the expansion and con- traction of the metal by heat and cold ; (4) It must be impervious to, and unaffected by, moisture and atmospheric and other influences to which it may be exposed. LEAD PIPES. 123 A Coating for Cast Iron Pipes. A bath made up of gas tar, Burgundy pitch, oil and resin, is kept at 400 F., and the pipes are laid in this until they are of the same heat as the bath, when they are set up on end to drain off. Weight of Lead Pipe per Foot Run. Diameter. Light. Middling, i Strong. Diameter Light. Middling. Strong Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. ^ in. pipe 1 1 H 2 in. pipe 6 8 in 2 1 11 2 2| : 10 1 y I 3 4 3 , 3i , 10 U 12 13 13 15 H 2* 4 H 4 , 14 16 17 If 3 4 5 4i ,, , 14 17 22 if 5 7 8 5 , 15 22 25 2 5 6 8 5 , 22 2i 8* 11 6 , 22 A Table Showing the Weight of Lead Pipes per Length in Lbs. Bore. Length. Common. Middling. Strong. Inches. Feet. Lbs. Lbs. Lbs. 4 15 16 I 15 24 27 30 1 15 30 40 43 H 12 36 44 53 H 12 48 56 67 2 10 56 70 83 g 10 70 89 100 Weight of Composite Pipe per Yard. inch inside diameter Lbs. Ozs. 13 fj lo 2 4 4 12 Usual Length of Coil. . 50 yds. . 50 . 50 . 50 50 . 40 30 . 25 20 124 GAS ENGINEER'S POCKET-BOOK. Weight of Block Tin Tubes per Yard. | inch inside diameter I Lbs. Ozs. 8 91 11" 14 1 1 inch inside diameter 2 inches diameter 2| 3 Weight of Copper Pipes. Per foot. . . 1| Ibs. 4 inches diameter . Lbs. Ozs. . 1 7 . 1 14 . 2 6 . 2 15 Per foot 3 Ibs. Soldering Tin. Flux may be resin and sweet oil, spirits of salts (hydrochloric acid), killed with zinc cuttings, or Baker's mixture. Solder. Two parts tin, 1 lead, melts at 340 F. Blow Pipe Solder. 1 parts tin, 1 lead. Flux. Dissolve zinc in hydrochloric acid until effervescence ceases ; filter the liquid, add i spirits of sal-ammoniac, and dilute with rain water. Flux. One part lactic acid, 1 part glycerine, 8 parts water. These two fluxes will not rust iron or steel. Weight of Black Sheet Iron and Boiled Brass. Wire Gauge. Per Sheet, 72 x 24 in. Per Sheet, 72 x 30 in. Per Sheet, 72 x 36 in. P r sq. foot. Sl:eet Brass, per sq. foot. Nos. Qrs. Lbs. Qrs. Lbs. Qrs. Lbs. Lbs. Lbs. 10 2 14 3 4 3 21 6* 5f 11 2 '4 2 19 3 6 5 Bi 12 1 26 2 12 2 25 H 4 13 1 20 2 4 2 16 4 4i 14 1 13 1 23 2 5 3| 3| 15 1 8 1 17 26 3 3 i 16 1 2 1 10 17 22 2f 17 27 1 6 13 H *l 18 24 1 2 8 2 2 1 - 19 21 26 3 1} If 20 18 23 27 }i 21 16 21 25 11 if 22 15 19 23 H H 23 14 17 20 H i 24 12 15 18 1 15 oz. 25 . 11 13 16 14 oz. 14 oz. 20 10 12 () 14 13 oz. 12 oz. SCREW THREADS. Whit worth' s Screw Threads. 125 Diar. of Screw. Diar. at bottom ofThread. Area at bottom of Thread. No. of Threads per In. Width of Nuts across Flats. Depth of Bolt Head. Diar. ofBolt Head. Inches. Inches. Inches. Inches. Inches. Inches. 'nches i 0929 006 40 338 A-j-JL F JL + JL i f 1341 1859 0141 0271 24 20 448 525 f + t* 4+4 f 4 2413 0457 18 6014 ^- + JL p i- + i 2949 0883 16 7094 il + JL p JL + JL I 4 346 0940 14 8204 1S + JL B | tt i 3932 1214 12 9191 |-fJL B w 4 4557 1626 12 1-011 1 + JL B i s 5085 2027 11 1-101 1 A F 1 11 571 2565 11 1-2011 IA + JL B ^-j-JL H F 6219 3037 10 1-3012 11. + JL F 1+4 14 ii 6844 3687 10 139 l|-f _JL B ll i 7327 4026 9 1-4788 iJL-i-A B f + 15 7952 4966 9 1-5745 lfg + i B 13 F 14 I*" 8399 5540 8 1-6701 1| + A B 8 U H 942 6969 7 1-8605 113-J--3. p 8+4 if 4 1-067 8941 7 2-0483 2A p 2 i it 1615 1-0592 6 2-2146 2A + JL B ] A + J_ H 2865 1-2999 6 2-4134 2f + -V F IA 2 ! if 3688 14715 5 2-5763 2A + JL B 1 1 + - - if 49 1-7525 5 2-7578 2| P }!+f 2 I if 5904 1-9865 41 3-0183 3j*- F 2 7154 2-311 41 3-1491 3 i + 4- B 11 3 2 8404 2-6602 41 3-337 3A + JL B 31 1-9298 2-9249 4 3-546 31 + A B iii-i- j_ 3| 2f 2-0548 3-3161 4 3-75 3f 2 ig + - 1 - 2* 2-1798 3-7318 4 3-894 31 + J& F 2A 3f 2f 2-3048 4-1721 4 4-049 4-3- F 2^ + ~ 3 j 3J 2f 2-384 4-4637 31 4-181 4JLB 2 ! + f 2 4 2i 2-509 4-9441 3J 4-3456 4-5- 4- JL F 4A 3 8 2-634 5-4490 3 2 4-531 4 + JL B 2f 4| 3* 2-884 6-5325 3i 3 3-106 7-5769 H 3f 3-356 8-8457 3 3-574 10-032 3 4- 3-824 11-481 ?1 H 4-055 12-914 4 4f 4-305 14-556 2 f 5 4-534 16-145 2f 5 4-764 17-826 2f 5 5-014 19-745 2 f 5f 5-238 21-548 2! 6 5-488 23-654 2* 126 GAS ENGINEER'S POCKET-BOOK. Wrought Iron Bolts (Whitworth Thread). Diar. of Screw. Safe Working Load, allowing a Stress 4,000 to 10,000 Ibs. Inches. 4,000. 5,000. 6,000. 7,000. 8,000. 9,000. 10,000. 26 33 . 40 46 53 60 67 ft 56 70 84 98 112 126 141 i 108 135 162 189 216 243 271 182 228 279 319 365 411 457 .| 253 347 409 478 546 614 683 & 376 470 564 658 752 846 940 * 485 607 728 849 971 1,092 1,214 & 650 813 975 1,138 1,300 1,463 1,626 r 818 1,013 1,216 1,418 1,621 1,824 2,027 a 1,026 1,282 1,539 1,795 2,052 2,308 2,565 t 1,214 1,518 1,822 2,125 2,429 2,733 3,037 1,474 1,843 2,212 2,580 2,949 3,318 3,687 1,660 2,013 2,415 2,818 3,220 3,623 4,026 if 1,986 2,483 2,979 3,476 3,972 4,469 4,966 i 2,216 2,770 3,324 3,878 4,432 4,986 5,540 H 2,787 3,484 4,181 4,878 5,575 6,271 6,969 ii 3,576 4,470 5,364 6,258 7,152 8,046 8,941 ij 4,236 5,296 6,355 7.414 8,473 9,532 10,592 H 5,199 6,499 7,799 9,099 10,399 11,699 12,999 ij 5,886 7,357 8,829 10,300 11,772 13,243 14,715 'l|: 7,010 8,762 10,515 12,267 14,020 15,772 17,525 1| 7,946 9,932 11,919 13,905 15,892 17,878 19.865 2 9,244 11,555 13.866 16,177 18,488 20,799 23,110 2* 10,640 13,301 15^961 18,621 21,281 23,941 26,602 2 11,699 14,624 17,549 20,474 23,399 26,234 29,249 2f 13,264 16,580 19,896 23,212 26,528 29,844 33,161 2| 14,927 18,659 22,390 26,122 29,854 33,586 37,318 2j 16,688 20,860 25,032 29,204 33,376 37,548 41,721 2| 17,854 22,318 26,782 31,245 35,709 40,173 44,637 2 19,776 24,720 29,664 34.608 39,552 44,496 49,441 3 21,796 27,245 32,694 38,143 43,592 49,041 54,490 3* 26.130 32,662 39.195 45,727 52.260 58,792 65,325 3 30,307 37,884 45,461 53,038 60,615 68,192 75,769 3f 35,382 44,228 53,074 61,918 70,765 79,611 88,457 4 40,128 50,160 60,193 70,224 80,256 90,288 100,320 4 45,924 57,405 68.886 80,367 91,848 103,329 114,810 4 51,656 64,570 77,484 90,398 103,312 116,226 129,140 4f 58,224 72,780 87,336 101,892 116,448 131,004 145,560 5 64,580 80,725 96,870 113,015 123,160 145,305 161,450 H 71,304 89,130 106,956 124,782 142,608 160,434 178,260 5J 78,980 98,725 118,470 138,215 157,960 177,705 197,450 5| 86,192 107,740 129,288 150,836 172,384 193,932 215,480 6 94,616 118,270 141,924 165,578 189,232 212,886 236,540 SCREW THREADS. Whitworth's Standard Screw Threads, 127 Outside Diameter in Inches. Diameter at bottom of Thread. Nearest Size for Drilling Number of Threads per Inch. Outside Diameter in Inches. Diameter at bottom of Thread. Nearest Size for Drilling Number of Threads per Inch. | 093 i 40 ft 455 y 12 i 112 32 * 508 33 11 I 134 165 & H 24 24 1 571 622 i 1 11 10 1 i 5 g 186 241 i 20 18 if 684 732 i 10 9 i 295 16 tf 795 i 9 346 23 14 1 841 i 8 I 393 1 12 Hoop Iron. B. W. Gauge. Width in Inches. Weight per Foot Run. Weiht per 100 Foot Run. B. W. Gauge. Width in Inches. Weight per Foot Run. Weight per 100 Foot Run. Lbs. Lbs. Lbs. Lbs. 12 2* 91 91-78 16 1| 27 26-52 13 2* 71 71-23 17 1* 21 20-84 13 2 63 63-31 18 1 16 16-16 14 If 48 47-15 19 7 12 12-37 15 H 36 36-37 20 ' 1 087 8-84 15 if 33 33-34 Rust Joint Cement for Cast Iron Tanks and Cisterns. Cast iron borings . . . 5 Ibs. Powdered sal-ammoniac . 1 oz. Flour of sulphur . . 2 ozs. Another and perhaps better cement is mix with water. Cast iron borings . Powdered sal-ammoniac Flour of sulphur . 6 Ibs. ) 1 oz. \ mix with water. 128 GAS ENGINEER'S POCKET-BOOK. Working Safe Stresses in Ibs. per Square Inch. Tension. Compression. Shearing. Cast iron . f '_," 3,000 10,400 2,700 Wrought iron bars . . 10,400 10,400 7,800 plates . 10,000 10,000 7,800 Soft steel, untempered . 17,700 17,700 13,000 Cast ., 52.000 52,000 38,500 Copper . . 3,600 3,120 2,300 Brass . . . . 8,600 2.700 Gun metal . 3,120 2,400 Phosphor brouze . 9,870 7,380 Comparative Weights. Cast Iron. Bar Iron. Steel. Brass. Copper. Gun Metal. Lead. Yellow Pine. Cast iron = 953 925 807 83 8288 64 16-0 Bar iron = .048 1 973 909 806 8087 67 16-8 Steel = 076 1-020 1 933 89 8917 688 17-0 Brass = i:>3 1-1 1-07 1 95 9558 737 18-8 Copper = 213 1-151 1-123 1-05 1 1-0004 774 19-3 Gun metal = 208 1-150 1-121 1-046 99 1 773 19-0 Lead = 504 1-5 1-453 1-357 1-29 1-292 1 24-0 Yellow pi ne= 1 Weight of a Foot Superficial of Parts of an Inch in Thickness. > i j. 4 I 1 1 I 1 IriPh. Steel . . 2-05 5-1 10-2 15-3 20-4 25-5 30-6 35 '7 40-8 W.iron . 2-50 5-00 10-00- 15-00 20-00 25-00 30-00 35-00 40-00 C. iron 2-35 4-69 9-37 14-06 18-75 23-44 28-12 32-81 37-50 Brass . . 2-84 5-68 11-35 17-03 22-70 28-38 34-05 39-72 45-40 Copper . Lead, cast 2-89 3-70 5-78 7-39 11-56 14-78 17-34 22-17 23-12 29-56 28-90 30-95 34-68 44-34 40-46 51-73 40-24 59-12 WEIGHT OF DIFFERENT METALS. 129 Weight per Square Foot of Various Thicknesses of Different Metals. 30 28 26 24 Standard Wire Gauges. 29 27 25 23 22 21 20 ig 18 17 16 15 14 13 , ] | & Lead. i i i | I i , 1 \ / i i 1 / i ' ' i j i ' i ' i j | ] / 1 1 i 1 i 1 i I i /\ 1 1 i i | /\ i ' i / : '! 1 1 i ' i i / i 1 M 1 1 i l i / i 5 1 ; i I i I / i [ 1 1 i i i i , i i i [ i ' i i ' 1 i 1 /, i i 1 1 1 ' 1 i j 1 / 1 1 Copper. i i ' i | J 1 j / ' / ! ' ' ! ' ! i i 1 i 1 , i i / i 1 i y i i , y Brass. * ! ' i i i /\ 4 / 1 i ' i i i / , / Steel. ! 1 1 i 1 / i ' i/ 4 Wrot Iron i i ' 1 1 i l / i / /i /x 1 ' i 1 j 1 J ' \ i i / / ' y * ! ' ' I ' 1 l 1 i / fi Cast lion i ! ! j , ' 1 1 1 / i /i / 2| 2 and Zinc. i i ] ' 1 1 i / i / i ' i 1 1 1 i / i j / 2 E J ' 1 ' ' i 1 ' 1 // / . // / ' i 1 /I i / ' / $ / , i 1 1 1 ] , i | / ! / | f \ / ! i [ 1 ' ' J i i i 3 1 i 1 I 1 i i ' i / A / V / i J ! ! ' ' 1 1 i / / i/ 2 / i i j i i ' ' ' ' / ] / ^ y i i ' 1 1 1 [ [ / 1 / / / 2 i i ) 1 i ! ! ! , ' i ! / i 7 / J / i i ' 1 1 i ' ' i ] | 2 / ; ' Z !/ i O I '' i l i i i / ! / /' 7 A ! i 1 i y / \ / i i i ' i , 1 / / / / , / i i i ii_l! i ' i i j / 1 / A 2 i 1 2 1 i 1 1 1 / | 1 / / / / ] i I y ' | / / / v i B ' ! ' 1 ' i '/ i ', y / /\ i i ro J | ' ,| 1 / , '/ > ' 1 i i IU i i * I//! 52 i i 1 1 ' 1 1 ' f v/ /, , i jj !' ' 1 y\ 2 // j i t i j i '/ 1 /v / 1 i S" 1 1 ' ' t Y 1ZJL i i ! ) ' ft // i , 1 i i j 'V ' yx/. / 1 i i 1 i i i r t w i , i i J '> Bf J ! i / m i , i i i i r K 1 i i 1 t I//P i i i / x i, | i ' i ! ! i \-JA iiii 1 i i 1 i , j i ^ g i , * | J , VJ. [ 1 1 i i&Af^*&f&f^*if Thickness of Metai in parts of an inch. 130 GAS ENGINEER'S POCKET-BOOK. Handy rule for weight of Wrought Iron Plate : 1 superficial foot of i inch plate weighs about 10 Ibs. Bound Rods, To find breaking weight of, square of diameter in \ inches = B. W. diameter* in j inches = wdght in ^ ^ yard Resistance to shearing of wrought iron bars, ultimate = 18 to 20 tons per square inch. Weight of Half-round Iron and Steel Bars. Breadth in Inches. Thickness in Inches. Sectional Area, Square Inches. Weight per Lineal Foot. Iron. Steel. 5 * 0-249 0-83 0-85 H i 0-273 0-91 0-93 if i 0-364 1-21 1-24 3 0-395 1-32 1-34 it 3 0-451 1-50 1-53 2 S 0-514 1-71 1-75 2i 1 0-859 2-86 2-92 2 1-097 3-66 3-73 Weight of Sheet Brass in Ibs. per Square Foot. Thickness. Weight Thickness. Weight Thickness. Weight Binn. in Binn. in Birin. in Wire Inches. Ibs. Wire Inches. Ibs. Wire Inches. Ibs. Gauge. Gauge. Gauge. No. 3 0-259 10-9 No. 11 0-120 5-05 No. 19 0-042 1-77 4 0-238 10-0 12 0-109 4-59 , 20 0-035 1-47 0-220 9-26 ,. 13 0-095 4-00 , 21 0-032 1-35 , 6 0-203 8-55 . 14 0-083 3-49 , 22 0-028 1-18 . 7 0-180 7-58 , 15 0-072 3-03 , 23 0-025 1-05 . 8 0-165 6-96 , 16 0-065 2-74 , 24 0-022 0-926 , 9 0-148 6-23 , 17 0-058 2-44 i 25 0-020 0-842 . 10 0-134 5-64 , 18 0-049 2-06 , 26 0-018 0-758 Comparative Strengths of Steel, Wrought Iron, and Cast Iron. Relative areas required to withstand a given strain. Tension. Torsion. Compression. Steel .... 2-23 3'33 1'43 Wrought iron . . . 4-44 5-00 5-23 Cast iron . . . 9-45 36*00 2'45 The cohesive power of iron and cement equals 40 to 47 kilometres per square centimetre. Iron embedded in cement docs not rust. WEIGHT OP BOUND AND SQUARE RODS. 131 Strength of Double-Headed Bails (Steel) Breaking weight at centre = 30 (a ~ + M67 t d*) a = area of one flange in inches. d = depth over all of rail in inches. d" = vertical distance apart of centres of flanges. t = thickness of web. L = length of span in inches. Weight of Hound and Square Iron and Steel. Iron. Steel. Iron . Steel. 1 Rd. Sq. Rd. Sq. 1 Rd. Sq Rd. Sq. I II || E| II I ii &! tt _iJ S| a S3 4V) bD c4 II 3>1 S S S^ VJ |l ii Sj 6 3 || *3 ^3 M H Ins. Lbs. Lbs. Lbs. Lbs. Ins. Lbs. Lbs. Lbs. Lbs. A 0-092 0-117 0-094 0-120 *1 11-82 15-05 12-06 15-35 i 0-164 0-208 0-167 0213 H 13-25 16-87 13-52 17-21 4 0-256 0-326 0-261 0-332 14-77 18-80 15-06 19-18 1 0-368 0-469 0-376 0-478 2 16-36 20-83 16-69 21-25 & 0-501 0-638 0-511 0-651 2| 18-04 22-97 18-40 23-43 I 0-654 0-833 0-668 0-849 2f 19-80 25-21 20-19 25-71 ft 0-828 1-060 0-845 1-076 H 21-64 27-55 22-07 28-10 1 1-023 1-302 1-043 1-328 3 23-56 30-00 24-Oi; 36-60 1-237 1-576 1-262 1-607 H 27-65 35-21 28-21 35-91 j 1-473 1-875 1-502 1-912 81 32-07 40-83 32-71 41-6.5 is 1-728 2-201 1-763 2-245 4 36-82 46-87 37-55 47--81 * 2-004 2-552 2-044 2-603 4 41-89 53-33 42-73 54-40 if 2-301 2-930 2-347 2-988 4|- 47-29 60-21 48-23 61-41 i 2-618 3-333 2-670 3-400 4! 63-01 67-50 54-07 68-85 i| 3-313 4-219 3-380 4-303 4f 59-07 75-21 60-25 76-71 4 4-09V 5-208 4-172 5-312 5 65-45 83-33 66-76 85-00 i| 4-950 6-302 5-049 6-428 5j 72-16 91-87 73-60 93-71 i* 5-890 7-500 6-008 7-750 5| 79-19 100-83 00-78 102-85 6-913 8-802 7-051 8-978 5| 86-56 110-21 88-29 112-41 if 8-018 10-208 8-178 10-412 6 94-25 120-00 96-13 122-40 9-204 11-719 9-388 11-953 61 102-27 130-21 104-31 132-81 2 10-472 13-333 10-681 13-600 e| 110-61 140-83 112-82 143-65 K 2 132 GAS ENGINEER'S POCKET-BOOK. NOTES ON WROUGHT IRON GIRDERS. Depth. The depth of girders in ordinary cases should be from ^ to Jg of span, if intended to serve as a parapet may be increased to |, in flooring . Weight. The weight in tons may be found approximately by multiplying the load to be carried by the total length of girder and dividing by 400. Strain. The safe strain when not given may be assumed at 5 tons in tension or 4 tons in compression per square inch. Bearing Surface. The bearing surface in square feet may be found by dividing the weight on abutment by one of the following constants according to the material of abutment, viz. : Granite 25, limestone 25, sandstone 15, firebrick 10, strong red brick 7, weak red brick 3. Camber. Half an inch rise per 10 feet length of girder. Area of Flanges. Section of top or bottom flange to girder at intermediate points from centre. 1. Distributed load. J, W x 2 -=; - = Section area of top or bottom flange in centre in square inches. 2. d = distance of point from nearest support. = Sectional area of flange at any other point in square inches. 3. x = Sectional area at any point. j? ^ - = distance of such section from nearest support. W Example. A girder 20 feet long carries a distributed load of 40 tons, and is2 feet deep, By (1) 40 x 10 = 10 inches sectional area. 2x4x5 By (2) Sectional area required 3 feet from end. 40 x 3 2x4x5 = 3 inches sectional area.. By (3) Suppose flange to be made of 3 plates, each 3'3 inches area, centre section will be 10 inches; section outside first plate will be 0-6 inches ; section outside second plate will be 3*3 inches. 10 x 2 x 4 x 5 _ 1Q feet distance of sec tion of 10 inches from support. feet 6 ii from en< length of plate 6 feet 6 inches. = 6 feet 6 inches distance of section of 2 plates from end = (20 feet - 13 feet 2 inches) = WROUGHT IRON GIRDERS. 133 3-3x2x4x5 _ 3 f eet 3 incheg digtance of sect i on o f j plate 40 from end = (20 feet - 6 feet 6 inches) = 13 feet 2 inches length of second plate. I 4 - 20(0' -I - 20'.0' p 73.2; ._- .4 jr----6. 6 --- tj Sction3-)" Section 6 6 Section 10 In rolled joists ith of the area of web may be included in each of the areas of the top and bottom flanges when calculating the strength of the joist. To find the net area of a joist in inches A _ W ^ . f -7- 5 = inches area if wrought iron. To find W = distributed load A X ^ X d = depth of girder in feet c ~ L x W ,, a = net section in inches 7^ =pr \j X U L = span > I x \\r S = tons strain per square inch 5 r -, o X A X (I 134 GAS ENGINEER'S POCKET-BOOK. /-s s, 'So f>> i 1 When it is required to know the nearest stock size of joist for any load and span find the load on bottom line, and note the vertical line for this load, then find the span on left hand side, follow the horizontal line opposite the span until it cuts the 4-> CO ! 3 a ,3 1 ?H 1 a s o > o 40 M 5 -i p3 on gj '' JS ii^.] nl:i Solf" sllll ^PJ d ' 3 "To Solid Circle. R = = -- = M Hollow Circle. Solid Elliptical Section. immMfa \ = -7854 BD 3 R = -7854 CBD2 MOMENTS OF INERTIA. Hollow Elliptical Section. T = -7854 (BD 3 - B'D rr , R _ -7854 C (BD 3 - B P' 3 ) 137 One Flange. I = | JBD 3 + B'D' 3 - (B' - B) D" 3 6D >.;. I = iBD 3 - (B - K) (D- C) 3 + BD' 3 - (B' - K) (D f - C' Wooden Joists (square or rectangular) " ^^ 0-23 a oak = Breaking weight in tons on centre. Cast iron beams 2d x area of bottom flange in inches _ L Area of top flange should equal one-third that of bottom flange. 138 GAS ENGINEER'S POCKET-BOOK. Wrought iron beams with top and bottom flange 6d x area of bottom flange in inches + th area of web _ ~L~ B and d in inches, L in feet. Rivet holes deducted when calcu- lating area of web and flange. Box girders are about 8 per cent, stronger than single plate girders. Relative Strength of Beams or Girders. Relative Strength. Supported at one end and loaded at the other = 1 ,, load distributed 2 both ends ,, at centre 4 ., distributed = 8 Firmly fixed at both ends and =16 Eule for Distributed Breaking Weight on Steel Joists. 8 x D x strain on bottom flange L D = depth. L = length. Strain = area of bottom flange -f Jth area of web x 28 tons per inch. Board of Trade Eegulations for Bridges. Greatest stress per square inch in any part not to exceed 5 tons either in tension or compression when made in wrought iron. When of cast iron the factors for dead load are taken and that portion of the load which is moving is doubled. When of steel the greatest stress per square inch not to exceed OJ tons. Fonts et Chausse"es allow 3-81 tons per square inch in wrought iron girders in compression or tension. Cast Iron Girders. If supported at both ends and centre load W = j- , ., distributed load W ='^L With distributed load, if d = A L, W = A 4-17 =AL,W = A5 If load is placed on top flange, area should = B If load is placed on bottom flange, area of top flange should = -g- Depth at ends should = CAST IRON GIRDERS. 139 With a test load = W, safe deflection equals inch per foot of span In the above W = breaking weight in tons. a = area of bottom flange in inches. d == depth of girder in inches over both flanges. L = span of girder in inches. If the depth of a wrought iron plate girder equals -JT , then strain on top or bottom flange at centre in tons equals distributed load. If the depth of a wrought iron plate girder equals , then strain on top or bottom flange at centre in tons equals 1 distributed load. If the depth of a wrought iron plate girder equals ,then strain on top or bottom flange at centre in tons equals 1^ distributed load. Continuous Girders. The distance of the point of contrary flexure from pier, when the load on each span is equal, is span. When the load is greater on one span than the other the distance equals (7 load on first span - load on the other \ - x span I 8 load on first span / The pressure on the abutments (7 load on. first span - load on the other \ Tfi ~ / / The pressure on centre pier equals f span (load on first span + load on the other). Thickness of Web Plates Required to Resist Diagonal Forces. (Chas. Light.) Thickness Net Unsupported Distance in Inches, whether between Pillars or Booms. of Web. 24 27 30 33 36 39 42 45 48 51 Inches. i 1-5 1-2 1-0 8 '7 6 5 45 4 36 A 2'8 2-2 1-8 1-5 1-3 1-2 I'O 9 ' '8 4-3 3'5 3'0 2'6 2'2 1-9 1-7 1-5 1-3 1-2 _z_ 6'3 5'3 4-5 3-9 3'4 2-9 2-6 2'3 2'0 1-8 i 8-7 7'4 6-3 5-5 4'8 4'2 3-7 3'3 3-0 2-7 JL 11-2 9-8 8'5 7'4 6'5 5-7 5-1 4'6 4-2 3'8 14-0 12-3 10-8 9-5 8'4 7'5 6-7 6-0 5-4 4'9 . 17-0 20-0 15-0 17-9 13-4 16-1 11-9 14'5 10-6 13-0 9'5 11-7 8'5 10-5 7-6 9-5 6-8 8-6 6-3 7 '8 Tabular numbers show safe thrust in tons per foot width of plate. Tabular numbers under distance required must not be less than the shearing force per foot of plate. no GAS ENGINEER'S POCKET-BOOK. Limits of Weights. &c,, of Wrought Iron that can be used without Increase of Cost. Length. Width. Area. Weight. Depth. Plates . . Bar Iron . L & T bars . Channel or E.J. . . 15 ft. 30 to 35 ft. 35 ft. 35 ft. 4 ft. flat bars, Gin. breadth and depth added H . . Y . 28 sq. ft. 4 cwt. 4 ,, 4 4 7 ins. Transverse Strength of Plates. (Deduced from Rankine.) Plate supported at 2 sides, distributed load, strength = Square 16W central L Circular, supported all round, distributed load, strength 3-1416 X Circular, supported all round, central load, strength 9-42 x Skbd* If firmly riveted to an immovable abutment, strength equals 1'5 above strengths. Formula to obtain Ultimate Strength of Angle, or Tee Iron or Steel Struts (as for struts in roof trusses). Breaking load in Ibs. per square inch of area of cross-section of pillar = Coefficient length in inches 2 least radius of gyration 2 x K Coefficient for wroughtiron equals 40,000. K = if both ends flat or fixed, 36,000 to 40,000. Coefficient for cast iron equals 80,000. K = if both ends hinged, 18,000 to 20,000. Coefficient for soft steel equals 52,000. K = if one end flat or fixed, other hinged, 24.000 to 30.000, LEAST RADIUS OF GYRATION. 141 least Eadius of Gyration. (Adapted from " Trautwine.") Equal Angles. Xl X X 1 X = -20 |J X ii. x i26 lfxlfxf = -35 2 x2 x^ = '40 2 x2 x $ = '38 2 x 2 J x i = '45 9i x 2ix ^ = '49 2|x2Jxi = - 2|x2fxi = 3 x3 x = 3 x3 x = 4x4x f= -81 4x4 x f= -80 5x5x ^=1-00 5x5x1 = -98 6x6 x i 7 g=M9 6x6x1 =1-17 Unequal Angles. 3 x2 3 x2 3 x2J 3 x2J 3^x3 = -64 x3 x3 x3 x3 x f = '67 x | = -65 5 x4 x f = -87 5 x4 xl =-86 6 x3x ^='82 6 x3ixl =-81 6 x4 x I 7 6 = '92 6 x4 xl =-91 6|x4 xl 10 =-93 7 x3fxl 8 = -84 Equal Tees. Unequal Tees. 1 xl -26 l|x l|x J=r-37 2 x2 xA = -43 2 xl x i = ' 3 x3 x 3x3i x 4 x4 x 3 x 2- x 3 x 3^- x 4 x2 2 x i = - 4 x3 x |= 4 x 3- x - = 4r- x 3-^- x - ~~" 5 2 x2|x | = O X 4: X T = ^ 86 88 91 72 70 Roughly, weight of wrought iron bridge may be assumed For 30 feet spans, single line, 5 cwt. per foot run 60 6 > 100 9 150 12 200 15 Dense crowds average 120 Ibs. per square foot. For flooring, H cwt. to 2 cwt. per square foot, exclusive of weight of flooring 142 GAS ENGINEER'S POCKET-BOOK. In storehouses, from 2 cwt. to 4 cwt. per square foot. Under no circumstances is a girder of less than ^th of the span advisable. Bolt Centres in Angle Irons. -c -i-fl q J.--IA ' A. B. I '*-' A. 11 f I 3| 2 1* 7 8 2 If 1* 41 3 If 1* 5 B. 24 c. If 1* 1* If 9 . _ _ 4^ x area of web below centre of gravity xtoliett I iron ^ \u breaking weight. A distributed load causes stresses only one-half as great as a centre load. A load at end of a projecting beam or cantilever causes stresses four times as great as a centre load. Size of L Iron laths for Slate Roofs. Distance Apart of Principals. Laths 12 Inches Apart. Laths 1 Navy allowance for storage = 48 . Coke in bays measures per chaldron 52 to 52^ cubic feet per chaldron. Coke diminishes in weight by exposure to the weather. (See also p. 232.) Average Weight of Various Coals. Per Cub. Ft. Solid. Per Cub. Ft Heaped. Cub. Ft. per Ton. Heaped. Per Cub. Yd. Solid. Anthracite Bituminous Cannel Coal as stored 85-4 Ibs. 78-3 .. 7i>-8 58-3 Ibs. 49-8 48-3 ., 38-4 c. ft. 45-3 40-4 2,160 Ibs. 2,100 2,190 1,150 Coal Stores. Coal stores in the open should be paved with a slope to carry off rain water. Ventilation of coal stacks may be effected by constructing open piers of brickwork or wood, or inserting perforated pipes, round which the coal is laid ; or wicker tubes. 146 GAS ENGINEER'S POCKET-BOOK. In designing walls for coal stores the object to be attained is to keep the centre of gravity of the mass of the wall as much towards the inner side as possible, as the strength of a wall to resist side pressures varies as the distance from the centre of gravity to the outside edge of the wall at the base, and as the weight on the foundations. On this account walls with panels sunk in are usually adopted. There can be little or no assistance from cross walls inside coal stores, or from the end walls, more especially when the walls are thick, a necessity where much coal has to be stored. The corners of such buildings frequently develop cracks from top to bottom of the walls nearly vertical, which would entirely remove any advantage which the side walls might have otherwise given. Probably the cause of these cracks is the expansion taking place in long walls exposed to the sun while the end walls are cool and shaded. Iron ties are not reliable when imbedded in the coals, as when the latter heat the ties extend, and the tension on the walls is relaxed ; and this may cause the wall to overturn through the upsetting of the centre of gravity of the wall. Mr. F. Marshall has designed a coal store with the floor a series of inverted pyramids, the sides of which are built of " Monier " concrete arches, the bottom points of the pyramids being so arranged that the coal may pass out in a regulated quantity on to a conveyer, and by this carried to the retort house. Stabling. Floor space required in stables per horse . . 120 square feet. Width of stalls for horses 6 feet. Width of building from wall to wall for stables 1 H ., Height of stables 12 A horse requires about 30 to 40 Ibs. food per day. Capacity of oat bins required per ton . . . 75 cubic feet. Capacity of hay lofts required per ton . . 500 Roads. A layer of hydraulic concrete at least 8 inches thick, or a foundation of 12 inches of gravel, well rammed in, with 1 inch of sand on top, should be laid under paved roads. Asphalt for roadways and for traffic should be 2 inches thick ; pavement of yards, covering of roofs, inch to 1 inch thick ; damp courses, | inch to f inch. The road surfacing asphalt is crushed, heated to 275 or 300 F., s^*ead uniformly where wanted, and stamped, rolled, and smoothed with heated irons. Coke breeze for tar paving footpaths best made by using water with the tar to ensure the distribution through the whole of the breeze. Twenty-four gallons tar to the yard of breeze is sufficient. RESISTANCE OF COMMON ROADS. 147 Grooves in Hobson's floor plates are best filled in with 112 Ibs. pitch, 85 Ibs. sand, and 56 Ibs. cement, with a little creosote oil on second boiling to make it pliable ; remainder filled in with tar concrete and rendered with 4 parts coarse sand to 1 part cement. Resistance to Traction on Common Eoads. (F. V. Greene.) . 10 Ibs. per ton. Asphalt . o 15 , Wood . Best stone blocks Inferior stone blocks Average cobble stone Macadam Earth 21 . 41 ,, , . . 33 , . 50 ., , on J7U ,, . . . . 100 , . 200 . Resistance of Surface of Different Roads. Stone tramway, exclusive of gravity . . . 20 Ibs. per ton. Paved roads ., . 33 Macadamised roads . 44 to 67 Gravel . 150 Soft sandy or gravelly ground, exclusive of gravity 210 The limiting gradients in ordinary roads are Asphalt 1 in GO ; wood, 1 in 25 ; macadam, 1 in 20 ; and granite, 1 in 15 ; but there are instances of macadam roads as steep as 1 in 6. The average resistance to traction upon road tranways is about 30 Ibs. per ton with a minimum of 15 Ibs. and maximum of 60 Ibs. per ton. Sir G. Molesworth stated (1895) that the greatest economical gradient for ordinary locomotives w r as 1 in 40. To set out a curve make a template to sketch. Where A C = the chord B D = versed sine. A pencil held at B when the template is moved round and kept close to nails at A and C will mark the curve required. L 2 1 48 GAS ENGINEER'S POCKET BOOK. Unloading Materials. A coal store should be well roofed in. and have an iron floor beddeo in cement, all supports passing through and in contact with the coal should be of iron or brick ; if hollow iron supports are used they should be made solid with cement. Under no conditions must a steam or exhaust pipe or flue be allowed in or near any wall of the store, nor must the store be within 20 feet of any boiler furnace or bench of retorts. (Prof. V. B. Lewes at Soc. Arts, 1892.) Tractive Power of Locomotives. D = diameter of cylinder in inches. L = length of stroke in inches. T = tractive force on rails in Ibs. P = mean pressure of steam in cylinders in Ibs. per square inch. W = diameter of driving wheel in inches. W In Permanent Way Work. Eight yards run of metals require 2 lengths rail cost (1894) 4 Is. 9d. per ton. 8 sleepers 2s. 4d. each. 2 pairs fishplates . . . . Wd. pair. 8 bolts at 1 Ib. (G = 5 Ibs. 11 ozs.) . 11*. per cwt. 32bolts(6 = 31bs.lOozs.) . . Ss.Wd. per cwt. Labour costs, say, Is. per yard run. Average weight of cast steel crossings (Vicker's patent), say 5 cwt. ; price, 1894, 32*. per cwt. Average cost of switchrails and stockrails, 1894, 5. Materials acquired per Mile of First Class Railway. Steel rails, bull headed, at 85 Ibs. per yard 133* tons. Chairs, 3,872, at 50 Ibs 86 Fishplates, steel clip, 352 pairs, at 40 Ibs. . fij Bolts and nuts, 1,408, at H Ibs.. . . 1 ton. Spikes, 7,744, at 1J Ibs 4| tons. Trenails, solid oak, 7,744 Keys, oak . 3,872 Sleepers, creosoted, 1,936 [n relaying, the old materials may be credited at 55 per cent, of the cost of the new work RESISTANCE ON RAILWAYS. 149 Usual Type of Bail used on English railways. The bull head of steel of 90 Ibs. per yard of an average length of 30 feet. Bessemer steel is most used. Rails are drilled at ends, and the bolts are of steel. Test for rails is one to three blows of a 1-ton weight falling from various heights ; the rail, placed on bearings 3 feet 6 inches apart, must not show any signs of fracture or exceed a given permanent set ; sometimes a further test is made by hanging a dead weight of 40 tons in centre of 3 feet bearings, giving a maximum deflection of -inch and no per- manent set after one hour's suspension. Eesistance of Curves. (Morrison.) W = weight of vehicle. R = radius of curve. F = coefficient of friction of 'wheels on rails = '1 to '27 according to weather. D = distance of rails apart from tread to tread. L = length of rigid wheel base. . A WF(D + L) Resistance due to curve = ^5 ZK. Elevation of Outer Rail on Curves. Width of gauge in feet x velocity in miles per hour 2 ( e i eva ti O n in 1*25 radius of curve in feet ~ I inches. Axle Tests are that they should be placed on solid bearings 3 feet 6 inches apart, and subjected to five blows of a 2,000 Ibs. weight falling 20 feet, the axle being reversed after each. For wagons the ultimate tensile resistance should be 35 to 40 tons and 25 per cent, elongation in three inches. Resistance of Trains. W = weight of carriage without wheels and axles. 10 = wheels and axles. D = diameter of wheels on tread. d = journal. F = coefficient of axle friction = say -035 with grease, '018 with oil. / = ,, n rolling friction = about -001. R = resistance of vehicle =/ (W 4- w) + ( WF 150 GAS ENGINEER'S POCKET-BOOK. Crane Hooks, deduced from Experiments at London and North Western Railway Company's Works. (Diameter of link of chain in Aths of an inch \ - g J = working load m tons. 6 = diameter of chain. K _ ( 1'15 times diameter due to twice area of 6 up to 10 tons. 1 1*2 _ ,, above 10 tons. A = 3 X Je -f C, B = % A + -9 C, E = If A, D = A X '8. S =A x J, T = Ax|, R = A, M = C, F = C. HYDRAULIC CRANES. 151 EETOET HOUSE. Best site for a Gas Works is the lowest point to be served, and, at the same time, close to the point of delivery of the raw material, such as a railway, canal, or river. Average consumption per head 2,000 cubic feet per annum in large towns ; 1,600 cubic feet per annum in medium sized towns ; 1,000 cubic feet per annum in small towns. Area of ground required for 7,000,000 cubic feet per day, 17 acres inclusive. (A. Colson.) Hydraulic Power pressure usually adopted 700 Ibs.per square inch. Old Beckton Hydraulic Cranes, nine in number, lift a total weight of 20 cwt. each designed to discharge 40 tons an hour with a lift of 60 feet. Two horizontal high pressure pumping engines equals 75 horse- power each, with 17 inches diameter and 17 feet stroke accumulator each engine would work the nine cranes ; but with a lift of 90 feet, as afterwards arranged, both engines are required. Cranes are multiplied 10 to 1, lifting chain travelling at 60 feet in 10 seconds, and the ram 6 feet in same time. Even with 90 feet lifts the cranes can easily lift 40 tons per hour, and have done considerably over that quantity. On the same pier are six steam cranes of the best type, requiring two 30 horse-power boilers to keep them going, whereas, with hydraulic power, two 20 horse-power boilers work one pair of pumping engines sufficient to actuate six cranes. The practical efficiency of the distribution of hydraulic power in towns may be taken as 50 per cent, to 60 per cent, of the power developed at the works. Loss of head due to velocity in hydraulic pipes (Gallons per minute) 2 X length of pipe in yards 3 X diameter of pipe in inches Friction of the ram of an accumulator may be taken as 2 per cent. Friction in steam engine pumping into accumulator may be taken as 8-3 per cent. Thickness of Hydraulic Cylinders. d. Where d = external diameter of the cylinder in inches, D = internal diameter of the same, also in inches. Loss of power by multiplying gear upon hydraulic rams varies from 7 per cent, when direct acting, to 50 per cent, when multiplying 16 to 1. Velocity of water in feet per second = 8 V height of fall in feet, where there is no deduction from the force for friction or other resistance. 152 GAS ENGINEER'S POOKET-BOOK. Saving by use of Conveyor and Priestman Grab. At a works using about 49,000 tons per annum _ Old style In barge 4 men 6,s-. ) On run 2 6#. ( per day. On crane 1 man 6*. 7 men plus wear and tear of trucks and run equals about 4d. per ton. New style -In barge 1 man 4*. 5d. } Conveyor engine 1 3*. 9d. V per day. Crane 1 4,9. M. \ 3 men plus wear and tear of elevator, conveyor engine, fuel, and interest on 1.200 (cost of elevator, conveyor, and engine), about l-8Qd. per ton. d. Craneman . . v . , = '45 per ton. Engineman and bargeman . = -60 ., Interest, wear and tear . . = -42 Coke, 6 sacks per day, and oil = -33 ., Average Composition of Fireclays. Peroxide Silica. Alumina, of Iron. Lime. Magnesia. Potassa. Titanic Acid. Soda. 65-0 28-0 4-6 0'3 0'35 1-2 0.25 0'3 Composition of Fireclay. Silica (Si0 2 ) . . . . 59 to 96 per cent. Alumina (A1 2 3 ) . . . . 2 to 36 Oxide of Iron (Fe 2 3 ) . 2 to 5 ., Lime, Magnesia. Potash, Soda . traces. The more alumina that there is in proportion to the silica, the more infusible the fireclay. (J. Hornby.) Dinas Bricks. Silica 95 per cent. Alumina and oxide of iron . 2 to 3 Lime 1 to 2 ., These bricks swell on burning, linear expansion 0-9 to 3-4 per cent., after being heated for 14 days to 1700 C. Silica in ordinary Stourbridge firebricks = (55 per cent. , Welsh = 95 Specific heat of fireclay . . . . = 0'21 ' FIREBRICKS. 153 Tests of Firebricks at Royal Arsenal. Cracked At. Crushed At. Stourbridge . 1,478 Ibs. 1,156 , per square inch 2,400 Ibs. per square inch i i - M O <> 5 > 1,512 ,, Newcastle Plympton Dinas . . . Kilmarnock . Glenboig . . 889 , 1,689 , 1.123 , 2.134 , 1,067 > 2,666 1,288 3,378 ., 1,556 ;, 5? Cubes 1 inch sides, cut from soaps, were used and placed between pieces of sheet lead. Fireclay Blocks Weigh per 100. Inches. 18X 9X3 24X16X3^ 24xl2x3i 1 3 2 8 17 19 3 1 1 1 Ellis and Grahamsley's, f Newcastle. 12X 9X 6x3| 1 15 }wV1oVi 9X 9X 6x3| 1 3 12 X 9X 6x3| 1 11 2 1 Mobberley and Perry's. General Notes. Ewell bricks are soft and not suitable for use where clinker bars- are liable to be used, and should be set in Bwell loam. Dinas firebricks fuse at about 3,880 to 3,930 F. Firebricks from magnesia are being made, and recommended for very high heats, containing 95 to 97'8 per cent, pure magnesia ; they are set in a mortar made up of magnesia powder. About \ ton of fireclay is required per 1,000 Newcastle firebricks used. If there be a thick joint or the broken corner of a brick where the flames from the furnace can get a hold upon, it will rapidly hollow out the brickwork at that point ; joints should therefore be very thin. Fireclay suffers no deterioration of quality from rain. Twenty-one cubic feet of dry ground fireclay firmly packed = 1 ton ; \1\ cubic feet of blocks = 1 ton. Retorts. A good retort will sound metallic when struck, but if under-burnt or unduly cracked will give a dull sound. H. Eeissner's Rule (Berlin Gas Works), 15 per cent, retorts in reserve in midwinter. For machine stoking with 20 feet through retorts, Mr. West suggests a space of 21 feet 6 inches in front of beds each side at least, and 18 feet extra length from the centre of the end retort to enable the machines to be run out of the way. 154 GAS ENGINEER'S POCKET-BOOK. The lowest point of the roof trusses should be 32 feet high from stage or floor line, at 11 feet from face of retort stack. Height of tie-beam of roof in retort house should be at least 20 feet above floor line. It is best not to allow floor joists in stage retort houses to bear upon the brickwork of the setting, owing to the great expansion and contraction of the latter. Openings in the roof of retort houses near the eaves have been objected to as likely to drive the smoke downwards. The openings in side walls of retort houses for ventilation should be above the level of the top of beds. Provide as few doorways on floor line as possible in retort house. Concrete under retort settings should be at least 1 foot below floor line. Space in front of benches should be 22 feet or 25 feet if machinery is to be used. It is likely to be cheaper to build the retort house of sufficient width to erect upon the stages the ordinary coal hoppers and bins, from which the coal can be elevated direct to charging hopper at any part of the machine's progress along the stage, by an elevator attached to the machine. (A. F. Browne.) Mr. Wyatt's Rule 1 foot run of retort house per ton carbonised per day or 6,000 cubic feet with floor area of 1,000 feet per ton per day, and costs 18 per cent, of total capital at a rate of d. per cubic foot all provided. Drain pipes to stoke-holes 9 inches diameter best laid with a fall of 3 inches in each 100 feet run, with 3 feet x 3 feet manholes to about every 100 feet (1 foot 9 inches of ground above the shallowest end). The loss of power in distributing energy by compressed air equals 50 per cent. Heat of one bed of retorts has heated a boiler 3 feet 6 inches diameter 9 feet long after heating the retorts, but this heat would have been better utilised if heating the retorts. A temperature of 1,500 F. is often found in flues of moderate sized works. Jointing for Mouthpieces to Clay Retorts. Two parts of sulphate of lime mixed with water, mixed well with six parts iron borings, with solution of sal-ammoniac, or three parts fireclay and 1 part iron borings (by weight) mixed with ammoniacal liquor. Cross Tie Rods to Benches should be capable of resisting a breaking strain of 60 tons, and longitudinal tie rods 100 tons, it is practically impossible to prevent the expansion of a setting when first lighted up, and the tie rod nuts should be only hand tight, and should be slackened if found necessary. End Bnckstaves for Stage Setting should be 12 inches x 5 inches H iron, 4 at each end, and tie rods to same 2 inches diameter. The top of a setting should be well covered or blanketed to prevent loss of heat by radiation. Division walls of settings should be not less than 18 inches thick. Space around Retorts should not be more than 4 inches wide at any point in clay retort settings. SETTINGS. 155 Clay retorts should be not less than 3 inches thick. Smooth inside surfaces to retorts assist in preventing the accumu- lation of carbon and in its subsequent removal. No setting should be used until at least 14 days after completion, and then gradually heated. Twenty-one inches X 15 inches x 20 feet D retorts will easily carbonise 5 cwt. of Newcastle coals in 6 hour charges. Through retorts are more economical than singles. Circular retorts allow a large space above the charge, and are therefore bad. The use of Thicker Walls in front of the bench has been advocated for the stoppage of the ascension pipe trouble. Coke is sometimes removed hot by a conveyor under the mouth- pieces, and carried by it to an elevator where it is quenched by water from a perforated pipe, raised and piled in place, the elevator being so arranged that a swivel spout at the top allows it to be placed where desired. The Size of the Mouthpiece should never be made, in any direction, smaller than the retort, as the coke can then be easily removed with- out jamming ; neglect of this precaution has caused the mouthpiece to be removed when drawing coke with machinery. " Use plenty of walls to support retorts, and of good thickness, the small increased quantity of fuel required to heat them is more than compensated by the life of the retorts and setting generally." " The brickwork in a setting should only be sufficient to uphold the retort, and to be of as small an area as possible at many points rather than large areas at few points." Allow 25 square inches Air Space per retort between fire bars in open hearth furnaces. In ordinary furnaces allow plenty of room above the fuel so that the CO may be converted into C0 2 before it passes among the retorts, say equal to the area of the fuel. Ordinary furnaces evaporate 12 cubic feet of water per 24 hours. With coal in furnaces, more space in flue ways required with increased supply of air. About 50 per cent, of the heat generated in an ordinary furnace escapes unused up the chimney. Allow about twice the theoretical quantity of air to ordinary furnaces, or some of the CO will pass away without being converted into C0 2 Each 3 Ibs. C requires 8 Ibs. O, or 35 Ibs. (460 cubic feet) of atmo- spheric air, for complete combustion. To estimate furnace efficiency : If T = temperature of smoke gases, t = temperature of air. o = specific heat of a cubic metre of CO 2 (= up to 150 C. = 0'4l! from 150 to 200 = 0'43, from 200 to 250 = 0'44, from 250 t to 300 = 0-45, from 300 to 350 = 0'46), c = specific heat of a cubi'j metre of or N (about 0-31), then the loss of heat, a, in the furnace for every kilogramme of carbon burnt, expressed in calories, is x = 1-854 (T - c + 1-854 (T - Q 100 ~'* C. 156 GAS ENGINEER'S POCKET-BOOK. Calorific value of 1 kilogramme carbon is 8080 calories ; therefore = proportionate heat lost by fire 1 kilogramme carbon forms T854 cubic metres of C0 a at C. and 760 minimum pressure. (Dr. G. Lunge.) Structural Cost per Mouthpiece of Different Settings. (W. R. Chester, 1894.) s. "* ' 55 16 5) )5 ti V 5- ~l I 1 , -M 176 GAS ENGINEER'S POCKET BOOK. Safety Valves. According to the Board of Trade rules the area of a safety valve for a boiler working at 50 Ibs. pressure is 576 square inches per square foot of firegrate. Another rule is A = g^-p + a Where a = area of guides of valve, P = absolute pressure of steam in pounds per square inch, W = weight of steam evaporated per hour in pounds, A = area of valve in square inches. Theoretically, only 7'5 per cent, of the calories developed in the furnace of a boiler appears as work in the engine. (Hirsch.) At a rough computation, petroleum burnt as fuel under a boiler should need only three-fifths the storage room of coal for the same duty ; and whatever further advantage calcium carbide has in point of compactness is mainly due to the superior efficiency of the gas engine to the steam engine. A non-condensing engine requires 3 Ibs. of coal per I.H.P. per hour. A condensing 2 Ibs. Set Boilers in mortar made of soft sand 2 parts, lime 1^ parts, sharp sand 1 parts, except where the bricks or lumps touch the boilers, when fireclay should be used. Mr. C. Gandon found that the foundations of a boiler made of furnace clinker and cement, with three layers of firebrick bedded in fireclay, had caught fire from the flues, and the whole mass of the foundations was on fire. Large flues around boilers cause a slow passage of gases. Area of chimney = 1<5 (area o firegrate in Squar ***? ^/height of chimney in feet Superheaters in boiler flues for superheating steam give a gain of 10 per cent, to 25 per cent., according to type of engine used. In Lancashire boilers all furnace flue seams should be below the grate bars, longitudinal joints of shell butted and fitted with covers inside and out, double riveted zigzag, with outer rows twice the pitch of the inner ones. For ordinary draught, when, say, from 20 to 25 Ibs. of coal is burnt per hour per square foot of firegrate, the average proportions to allow per I.H.P. are square foot of firegrate. 2| of heating surface. 1J cubic feet of water space. I of steam space. English coal will evaporate 8 to 9'88 Ibs. water at and from 212 F. Scotch coal will evaporate 6'69 Ibs. water at and from 212 F. Fuel consumption per I.H.P. may be anything from 1-3 Ibs., according to class of boiler, engine, and method of working. Boiler Chimneys. Allow 3 square feei chimney area for each full-sized Lancashire boiler, or 4 square feet for a single boiler ; height of chimney same as others in neighbourhood, preferably not less than 90 feet high. CHIMNEYS. Dimensions of Chimneys. (R. Wilson.) 177 Area of Top Height of Chim- ney. Feet. Lbs. of Coal per Hour per 1 Foot Area at Top of Chimney. Height in Inches of Water Balanced by Draught Pressure. H.P. of each Square Foot of Chimney at 7 Ibs. Coal per H.P. Area of Top of Chimney in Feet per H.P. for 1 or 2 Boilers. of Chimney in Feet per H.P. where several Boilers work Area of Flue in Feet per H.P. together. 30 78-24 218 7-3 146 091 182 40 90-35 296 8-4 126 077 155 50 101-01 364 9-4 113 070 140 60 110-65 437 10-3 103 C64 129 70 119-52 5 11-2 095 059 ' 119 80 127-77 58 11-9 089 055 111 90 135-52 656 12-6 084 052 105 100 142-85 729 13-3 08 05 100 125 159-71 911 14-9 071 044 089 150 174-96 1-09 16-3 065 04 082 175 188-98 1-26 17-6 060 038 075 200 202-03 1-45 18-8 056 035 070 225 214-28 1-64 20-0 053 033 066 250 225-87 1-82 ,i 21-0 05 031 063 275 236-90 , 1-99 22-0 048 03 06 300 247-43 2-18 23-0 046 028 057 Armstrong proposes from 20 to 40 per cent, above these sixes, and to allow for additions to boilers it would be advisable to exceed above sizes to that extent. Proportion of Chimneys. Diameter of base, ^th height. Brickwork 9 inches thick for the top 25 feet. Brickwork 14 inches thick from 25 to 50 feet from the top. Brickwork 18 inches thick from 50 to 75 feet from the top. Brickwork 23 inches thick from 75 to 100 feet from the top. Increasing 4^ inches thick for every extra 25 feet. Knle for Area of Chimney if 21 Ibs. of Coal are Consumed per Square Foot Grate Area per Hour. Area of firegrate, in square feet, X H + *J height in feet = area in square feet. Or, one-eighth to one-tenth grate area = area of chimney. .Draught of Chimneys. 1 cubic foot air at 30" Bar. and 60 F. = 0-0763 Ibs. and varies as absolute temperature. Then if chimney gases are at 550 F- 0-0763 X (460 + 60) 4b'0 + 550 0-0763 - 0-0393 = 0-037 Ibs. per foot height per square foot area of chimney or height of chimney for 1" draught in feet 5-21 (= Ibs. per square foot of 1" pressure) _ ^ ,, ~&WT- Or, approximately draught in inches of water = 0-0075 x height chimney. Then 0-0075 x 111 - 1 -0575 inches draught. of chimne G.E. 178 GAS ENGINEERS POCKET-BOOK. To Find Size of Chimney Required. For a low-pressure engine, when above 10 H.P., the area of the chimney in square inches should be 280 times the horse-power of the engine divided by the square root of the height of the chimney in feet. (Joshua Milne, of Olclham.) Or, multiply the square root of the chimney height in feet by the square of its narrowest internal diameter in feet ; half the product will be the horse-power the chimney is equal to. 90 v TT P Or, for circular chimney, the diameter = ^/height in feet Or, firegrate should /have 1 foot area per horse-power, one-fifth area of firegrate, gradually diminishing to a chimney which shall' have one-tenth area of firegrate, is excellent proportion. (Cresy.) O r> 2 x 112 x cubic feet evaporated per hour __ S q uare i nc hes \/height in feet area> Coal Consumable by Chimneys of Different Sizes. (D. K. Clark.) Chimney. Coal. Hour. Grate Area. Chimney. Coal per Hour. Grate M.rea. Height. Diameter. Height. Diameter. Feet. Ft. Ins. Lbs. Sq. Ft, Feet. Ft. Ins. Lbs. Sq. Ft. 40 1 4 142 9-5 110 3 8 1777 118-4 50 1 8 248 16-5 120 4 2208 147-2 60 2 390 26-0 135 4 6 2964 197-6 70 2 4 574 38-3 150 5 3858 257-2 80 2 8 801 53-4 165 5 6 4896 326-4 90 3 1076 71-7 180 6 6086 405-7 100 3 4 1394 93-0 200 6 8 7920 526-6 Diameter = height ; coals consumed, 15 Ibs. per square foot per hour. Metropolitan Board of Works Regulations as to Factory Chimneys. Base of shaft to be solid up to top of footings ; projection of footings equal all round, and to thickness of wall at base. Width of shaft at base, just above footings : If square on plan, at least T ^th total height. If octagonal on plan, at least JLth total height. If circular on plan, at least J 5 th total height. Batter at least 2J inches in every 10 feet, or 1 in 48. Brickwork at least 8J inches thick at top and for 20 feet down, and increased 4 inches for every 20 feet additional height ; firebrick lining to be separate, and not included in above thicknesses. Cornice not to project more than the thickness of walls. CHIMNEYS. 179 Velocity of gases up the chimney being proportional to the square root of the height, increased duty would be better obtained by larger diameter than by greater height. The heavier the materials of which a shaft is built the greater would be its stability, the foundations being good. Batter of chimneys may equal 1 in 36. Theoretical draught power of chimneys with external air = 60 F.; internal heated air = 580 F. (coefficient in practice *3). Height of Chimnev in Feet! Draught in Inches of Water. Theoretical Velocity in Feet per Second. Cold Air Entering. Hot Air at Outlet. 50 367 40-0 80-8 60 440 43-8 87-6 70 514 47-3 94-6 80 587 50-6 101-2 90 660 53-7 107-4 100 734 56-6 113-1 120 880 62-0 123-9 150 1-101 69-3 138-6 175 1-285 74-8 149-6 200 1-468 80-0 160-0 225 1-652 84-8 169-7 250 1-836 89-4 178-9 275 2-020 93-8 187-6 300 2-203 98-0 196-0 (Bancroft.) The wind pressure on chimney shafts may be taken as acting upon the centre of gravity and in a horizontal direction, and the over- turning moment equals the height of the centre of gravity (/-) above the point at which it is desired to obtain the strength, as at a J, x wind pressure on chimney ; the least moment of stability must therefore exceed this {for figure see next page). The pressure of the wind will tend to move the centre of pressure on a b, towards the leeward side. To obtain the moment of stability of any shaft take weight of shaft above a b x ^ a b. Kankine says a factor of safety of 2 is necessary for round shafts and of | for square shafts. It has been said that the limiting position of the centre of pressure is permissible to be at one sixth of the diameter from the leeward side for square shafts, and one quarter of the diameter from the side for round shafts, only when the brickwork becomes infinitely thin. Firebrick lining to boiler chimneys need not be more than one half, or at most two thirds, the total height. If wind pressure on square shaft = 1 then ., hexagonal shaft = '75 octagonal shaft = '7 3 circular shaft = -5 (Bancroft.) N2 180 GAS ENGINEERS POCKET-BOOK. LIGHTNING CONDUCTORS. 181 Chimney shafts should not be joined to any other work of buildings, in case of settlement or expansion. Grouting is not advisable, as wet mortar possesses little adhesive power ; and the building should not proceed at a greater rate than 2 feet to 3 feet per diem. Only one course of headers should be used in large chimneys to three or four of stretchers. Capping stones should be light and joined with copper cramps at joints, as iron rusts and expands, when the stone may split and fall. Stock bricks will bear a heat of 600 F. without damage. Higher heat at exit of chimney than 580 F. or 305 C. is wasteful. Less exhaust than inch water bad. 580 F. gives a head of external air equal to half the height of chimney. By the usual rule, the external diameter at base of chimney should be about ith of the height, and the batter f g inch to inch per foot on each side. It is frequently stated in treatises on chimney designs that the diameter at the base should be ^th to ^th the height, but, having regard to the paramount importance of width of base, the width obtained by this rule is insufficient. For further remarks on chimney shafts, see Bancroft on " Design of Tall Chimneys." Lightning Conductors. Copper is the best ; but, when corrosion is not anticipated, iron of larger dimensions may be used (conductivity of iron equals |th that of copper). General dimensions of copper conductors : Rods inch diameter, tubes f inch diameter, | inch thick ; or bands 1 inch wide f inch thick. General dimensions of iron conductors : Kods 1 inch diameter, bands 2 inches wide x f inch thick. Radius of protection of lightning conductors equals height from ground. Sir William Thomson's (Lord Kelvin's) note advocates the use of the flat (tape or sheet) form of conductor in preference to the tubular or solid; and, if copper be used, its weight should be about 6 oz. to the foot ; if iron, about 35 oz. It quotes Lodge's recommendation that the conductor should be connected with the water or gas mains if in any part of its course it goes near them, but concedes that independent grounds are preferable. It gives the usual advice as to electrical connection with masses of metal built into a building, and warns against the neighbourhood of small-bore fusible gas pipes and indoor gas pipes in general. It prefers clusters of points, or groups of two or three, along the ridge rod, to other arrangements, and regards chain or link conductors as of little use. That the area protected is one of a radius equal to twice the height of the rod from the ground, or even, as some conductor manufacturers aver, a radius equal to the height, is denied. No such thing as a definite area exists. That lightning follows the path of least resistance is also controverted, for, in exceptional instances, when the flash is of a certain kind any part >f a building is liable to be struck, whether there is a conductor or not 182 GAS ENGINEER'S POCKET-BOOK. Lightning may also, contrary to what is generally held, strike twice in the same place. Doorways of barns, chimneys, and fireplaces are dangerous places, but the smaller articles of steel, such as knives, &c., have no influence on the path of discharge. The best made-ground for the earth-plates is, for some flashes, but a very poor one ; damp earth or running water are still the best terminations known. Steam Pipes. Thickness of steam pipe in IGths of an inch equals diameter (inches) -f- 4 up to 100 Ibs. pressure. D P Above this T = + T = thickness in inches. TjOOO Steam should have a velocity of about 6,000 feet per minute through steam pipes ; same for ports of engine. To find diameter of steam pipes for any engine : * / Sq. of cylinder diar. in inches x piston speed in feet per mm. 6,000 = The required diameter of steam pipe. 100 feet of 4-inch pipe would waste as much heat per annum as the consumption of 50 tons of coal would supply. With an efficient lagging it is to be supposed that most, if not all, of this would be saved. (Mr. G-eipel.) Allow 1 inch expansion in 50 feet in steam pipes. A 4 H.P. engine requires only 2-inch diameter steam connections. Exhaust Pipe. To prevent undue back pressure velocity of steam should not be greater than 4,000 feet per minute. To find diameter of exhaust pipe : Square of cylinder diameter x piston speed in feet per minute 4,000. The square root of the quotient gives diameter of pipe in inches; same for ports of engine. Condensation. The water required for condensation is about 20 times that required for the feed - approximate area of condensing surface = heatinjr surface x 0*7. Comparative Efficiency of Non-conducting Materials. (Emery.) Wood felt 1-000 Mineral wool, No. 2 -832 with tax -715 Sawdust -680 Mineral wool, No. 1 M>7<> Charcoal '(J',V2 Pine wood, across fibre '553 Loam, dry and open '550 Slaked lime '480 Retort carbon -470 Asbestos -363 Coal ashes '345 Coke in lump '277 Air space undivided '136 DISTANCE BETWEEN BEARINGS OF SHAFTS. 182 Diagram showing Span between Bearings of Shafts. Feet centres of Journals. C = 6 C = 4-5 From the rule S = C v S = span between bearings in ftet. % where D = diameter of shaft. f 5 to 6 for shaft only, without pulleys. C = ] 4-5 to 5 lor shaft, with ordinary number ' of pulleys and wheels. 184 GAS ENGINEER'S POCKET-BOOK. Non-Conductors for Steam Pipes. (Prof. J. M. Ordway.) Lbs. Wate Lbs. Water Heated Heated Substance, 1 Inch Thick. 10 F. Substance, 1 Inch Thick. 10* F. Heat Applied, 310 F. per Houi Heat Applied, 310 F. per Hour through through 1 Sq. Ft. 1 Sq. Ft. Loose wool . 81 Air alone . . . 4S-0 Live-geese feathers . 9-6 Sand .... 62-1 Carded cotton 10-4 Best slag wool . . 13-0 Hair felt . . . 10-3 Paper .... 14-0 Loose lampblack Compressed ditto . . 9-8 10-6 Blotting paper, wound tight 21-0 Cork charcoal White pine charcoal . 11-9 13-9 Asbestos paper, wound tight 21-7 Anthracite coal powder 35-7 Cork strips, bound on 14-6 Loose calcined mag- Straw rope, wound nesia 12-4 spirally . . . 18-0 Compressed calcined Loose rice chaff . 18-7 magnesia . 42-6 Paste of fossil meal Light carbonate of with hair 16-7 magnesia . 13-7 Paste of fossil meal Compressed carbonate with asbestos . 22-0 of magnesia . 15-4 Loose bituminous coal Loose fossil meal . . 14-5 ashes 21-0 Crowded fossil meal . 15-7 Loose anthracite coal Ground chalk (Paris ashes 27-0 white) 20-6 Paste of clay and Dry plaster of Paris . 30-9 vegetable fibre 30-9 Fine asbestos 49-0 Notes on Pumps. A man exercises more power with an ordinary pump handle than with a crank and handle. The power exerted by an ordinary man in working a pump handle continuously must not be estimated above 25 Ibs. The suction and delivery pipes of pumps should not be less than one half the diameter of the barrels ; and if the length be great, they should be larger ; also with large pumps or pumps working fast it is well to have a greater proportion of pipe area (in some cases the pipe is made as large as the barrel). The suction pipe should also be larger than the delivery pipe, as in the suction pipe there is only the atmospheric pressure to overcome the friction, whereas in the delivery pipe there is the whole power of the pump. The following is a safe rule for the sizes of suction pipes. An advantage is gained by using a large suction pipe, even if the inlet of the pump be smaller than the pipe. Inch. Inch. Inch. Inch. Inch. Inch. Inch. Size of pump 2 2-J- 3 34- 4 5 6 Siee of suction 1 H 2 2 2 3 4 PUMPS. 185 These sizes hold good for double pumps, as each barrel draws alternately, and therefore the pipe need not be increased in size. In laying a long length of suction pipe make sure that it falls along its whole length from the pump towards the well. If there is any point higher than the pump end of the pipe it will form a pocket or trap from which it will be very difficult to draw the air. It is always desirable to have a foot valve in the suction pipe to retain the water when the pump is standing. To avoid concussion and equalise the working of the pump it is well to place a vacuum vessel on the pipe just before it enters the pump. Formula for calculating the power required to raise water : Gallons per minute x height in feet = horse-power 3,300 Add for friction according to the machinery used and length of piping. Capacities of Pumps. Dia- meter. Inches. Area in Inches. Displacement in Gallons per Foot of Travel. Dia- meter. Inches. Area in Inches. Displacement in Gallons per Foot of Travel. i 0129 0005 4* 14-18 6125 | 0490 0021 4i 15-90 6868 1104 0047 4f 17-72 7655 I 1963 0084 5 19-63 8480 3068 0132 H 21-54 9348 ! 4417 0190 5 23-75 1-026 i 6018 0259 5f 25-96 1-121 i 7854 0339 6 28-27 1-221 ii 9940 0429 6J 30-67 1-325 H 1-227 0530 6i 33-18 1-433 if 1-484 0641 8| 35-78 1-545 H 1-767 0763 7 38-48 1-662 if 2-073 0895 74 41-28 1-783 if 2-405 1038 7f 44-17 1-908 if 2-761 1192 7f 47-17 2-037 2 3-141 1356 8 50-26 2-171 *i 3-546 1531 8| 53-45 2-309 2i 3-970 1717 8} 56-74 2-451 21 4-430 1913 8| 60-13 2-597 2J 4-908 2120 9 63-61 2-747 2* 5-411 2337 9* 67-20 2-903 2| 5-939 2565 9} 70-88 3-062 ' 2 6-491 2804 9f 74-66 3-225 3 7-068 3053 10 78-54 3-393 S| 7-669 3313 10* 82-51 3-564 3* 8-295 3583 10* 86-59 3-740 N 8-946 3864 lOf 90-76 3-920 3* 9-621 4156 11 95-03 4-105 N 10-32 4458 11* 99-40 4-294 3| 11-04 4769 IH 103-8 4-484 3 11-79 5193 nf 108-4 4-682 4 12-56 5426 12 113-0 4-881 186 GAS ENGINEER'S POCKET-BOOK. The following rule shows how to determine the dimensions of the feed pump : Let D = diameter of steam cylinder in inches. L = length of stroke up to point of cut-off in inches. s = stroke of pump. d = diameter of pump. v = volume of steam obtained from 1 cubic foot of water at the given pressure. Then d = 21 Force pumps should be twice the diameter of the pipes in connec- tion. Horse-power required to raise water equals quantity of water to be raised in gallons per minute X 10 X height to be lifted in feet divided by 33,000. Add to for losses by slip of valves and friction. Table of Pedestal Proportions. (Unwin.) Dia- meter of Journal. Inches. Length of Bearing. Inches. Height to Centre. Diameter of Bolts. Size of Bolt Holes. Length of Base. Centres of Cap Bolts. Centres of Base Bolts. Thick- ness of Step at Bottom. li 2* 4 \ |xi 81 H *i ito& 2 3 2f fxii 11 4f 9 /ii I H 8* *k | ixU 13i H 10J 5 7 TO 16 3 4 81 i i xif 15i *l |2| 1 i 3i !* 4 1 Uxif m 7 H! 1 J 4 5 H l| HX2 20 7* WJ 7^ i 10 16 5 6 6 If lfX2i 24 9i 19| i t 6 7 7 1| 1JX2J 28i llf 23f JL 13 10 16 7 8 8* Two li lfX2i 12i 1 i 8 9 9* . H 1IX2J 14 tt 1 9 10 10i if l*X2i 15} 1 1 10 11 11* if 2 X2f m 1 li 12 13 18J 2* 2|X3| 21 1 li From seven inches upwards the pedestals have two bolts on each side, both in cap and base plate. Length of Engine Journals. The higher the speed the greater the length of journal required. At 150 revolutions per minute one diameter is sufficient ; at 1,500 revolutions per minute 6 or 8 diameters are better. Coefficient of Friction with Dry Surfaces, Metal on metal 0'15 to 0-20 Wood 0-25 to 0-30 Millboard ., 0.20 GEARING. 187 When polished steel moves on steel or pewter properly oiled the friction is about of its weight ; on copper or lead |, on brass . Metals working on same metals give more friction than when on different metals. 3 /p x i Diameter of engine crank shafts = & P = pressure of steam on piston. Z = length of crank in feet. K=80 for iron, 120 for steel. Safe Speed for Flywheels. Maximum safe circumferential velocity of cast iron flywheels is 80 feet per second. Speed should not exceed in revolutions per minute 1530 mean diameter in feet. Width of Rim of Pulley for Belts of Various Widths. (Unwin.) Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Width of belt 2 3 4 5 6 8 10 12 Widthofpulley 2| 3J 5 6 7 9* llf 14 Thickness of edge of rim equals 0'7 thickness of belt -j- '005 times the diameter of pulley. Radius of rim face equals 3 times to 5 times the breadth of rim. Diameter of pulleys should not be less than 6 to 8 times the dia- meter of a wrought iron shaft suitable for transmitting the power transferred to the belt, and the diameter of the smaller of two pulleys should not be less than about 18 times the belt thickness. Breaking weight of machine belting, leather, per square inch equals 1'9 tons. Leather hose and driving belts for machinery treated with castor uil have been found to last longer, and when impregnated will not slip. A 3-inch belt treated with castor oil equals a 4i-inch belt without oil, and will last more than twice as long. Proportion of Teeth of Wheels. Depth = pitch x '75 Working depth = x '70 Clearance = ., x '05 Thickness = pitch x '45 Width of space = ., x -55 Play = x -10 Length beyond pitch line = pitch x -35. Common Proportion of Keys. (Unwiu.) Diameter of eye of wheel or boss of shaft = d Width of key = 1> = \d + Mean thickness of sunk key = t = \d + J key in flat = ?i= fal + -,! 188 GAS ENGINEER 8 POCKET-BOOK. In toothed wheels T. of tooth = -48 pitch. Width of space = '3 pitch. Height above pitch line = '3 pitch. Depth below pitch line = '4 pitch. A good new leather belt has a tenacity of from 3,000 to 5,000 lbs c per square inch of section. Coefficient of friction is about '423 between ordinary belting and cast iron pulleys. If leather belting has a tenacity of 1,000 Jbs. per inch of width the strength of a riveted joint may be taken at 400 Ibs., a butt-laced joint at 250 Ibs., and an ordinary overlapped laced joint at 470 Ibs. Effective working stress of ordinary single belts 50 Ibs. light double 70 ,, heavy double 90 Diameter of pulley should be more than 100 times the thickness of the belts around it. Ratio between two pulleys ought not to exceed 6 to 1. Convexity of pulleys equals J inch per foot in width. Centrifugal action on belts may be ignored at ordinary speeds up to 3,000 feet per minute. Internal friction in ropes driving pulleys is the principal destructive agent. Breaking strain of good icpes = 4 tons per square inch. Working = 300 Ibs. per square inch. Ropes should not be driven above 4,700 feet per minute. Cotton appears to be best for driving pulleys. It is said that belts should be made heavier and run more slowly than ordinary rules state to save cost in long run and prevent stoppages for relacing and repairing. At intervals of three months each belt '-should be scraped cle:m and dubbed. Working Tension of Belts (Leather). Thickness of Belt (in Inches) . . T 3 H A } T 5 f * ft i tt i Tension in Lbs. pr Inch Width GO 70 80 100 120 140 160 180 200 220 24o Single. Double. Usual Proportions. Width of Belt (in Inches) . 2 3 4 6 8 10 12 15 Thickness (Inch) . . . . 0-14 17 20 24 28 32 35 3D Working Tension in Lbs. per Inch of Width . . 45 55 64 78 90 101 110 124 ROPE GEARING. 189 Horse-power of different sized Manilla Ropes at different speeds Working stress = ^th, breaking stress = Jfeth strength of splice. Horse-powers. 5 10 15 20 25 30 35 40 45 ISO 140 130 a 70 * 1 60 10 20 25 30 35 40 45 Horse-powers. 190 GAS ENGINEER'S POCKET-BOOK. Width of Belts in Inches when Velocity of belt in Ft. per Sec. The Horse-power Transmitted is 1 2 4 5 l 10 15 20 25 1 15-7 31-4 47-0 63-0 2* 6-3 10-6 18-8 25-2 31-2 46-8 5 3-1 6-3 9-4 12-6 15 c, 23-6 31-4 47-2 H 2-1 4-2 6-3 8-4 10-4 15-6 21-0 31-2 42-0 52-4 10 1-5 3-2 4-7 r,-4 :> 11-8 15-7 23-6 31-4 39-2 12i 1-3 2-5 3-7 5-0 6-4 9-4 12-6 18-8 25-2 31-2 15 1-1 2-1 3-1 4-2 5-2 7-8 10-5 15-6 21-0 26-2 20 79 1-6 2-4 3-2 3-9 5-9 7-9 11-7 15-7 19-6 25 63 1-3 1-9 2-6 3-1 4-7 6-3 9-4 12-6 15-6 30 1-1 1-6 2-2 2-6 3-9 5-2 7-8 10-5 13-1 35 1-3 1-7 22 3-4 4-5 6-8 9-0 11-2 40 1-5 2-0 2-9 3-9 5-9 7-8 9-8 45 1-8 2-6 3-5 5-2 7-0 8-8 50 1-fi 2-4 3-2 4-7 0-3 7-8 60 1-3 2-0 2-fi 3-0 5-2 6-5 70 1-1 1-7 2-2 3-4 4-5 5-6 80 1-5 2-0 2'1 3-9 4-9 90 1-3 1-8 2-6 3-5 4-4 100 1-2 1-fi 2-4 3-1 3-9 Thickness of belt inch. (Unwin.) Modern Gas Engines. Compression of charge = 89 to 90 Ibs. per square inch. Initial pressure at moment of explosion = 300 Ibs. per square iivSi Consumption per effective horse-power = 16 - 48 cubic feet. Actual efficiency = 28'26 per cent. Mechanical efficiency = 86 per cent. Fuel consumption per I.H.P. = 0'8 Ib. anthracite coal. Gas Engines. The consumption of gas is now under 16 cubic feet per horse-power. The governors of gas engines control the valve that admits gas to the cylinder. When the speed is low gas is admitted, and an explosion puts new energy into the flywheel ; when the speed is high, no gas is let in and no explosion takes place. Ignition is chiefly by means of a Bunsen flame in England, and by electric spark on the Continent. In the " Otto " cycle gas engines the gas and air are drawn in by a forward motion of the piston, on the return stroke it is compressed, at the commencement of the next forward stroke it is ignited and the piston is moved forward, the return stroke expelling the products of combustion. Modern gas engines of best type compress the charge to from 40 to 6Q Ibs. per square inch before ignition. GAS ENGINES. 191 Mean effective pressure in " Otto" cycle gas engines = 50 to GOlbe. per square inch. Gas engines of 100 brake horse-power and upwards are now made to consume not more than 20 cubic feet of town gas per horse-power per hour at full load. Experiments made show that the deleterious effect of burnt gases is much overrated in the case of coal gas products in gas engines. (F. Grover.) Consumption per brake horse-power per hour at half load with gas or steam engines is about 40 per cent, more than at full load. Gas Engines. Cubic Feet Gas B. H. P. per B. H. P. Hour. Simplex . . . 8'79 . . . 20-38 Atkinson Cycle . . 4-89 . . . 22-5 Forward . . . 4-8 . . 23-97 Otto Crossley . . . 14-7 . . . 241 Atkinson's Differential 2-6 . . 25-7 Griffin .... 12-5 . . . 28-5 Clerk's Eiigiiu . . 7-2 . . . 30-4 Horse-power of Gas Engine. The indicated horse-power is equal to the mean effective pressure in pounds per square inch multiplied by the length of the stroke in feet by the area of the piston in square inches and by the number of explosions per minute, and divided by 33,000. Gas engine diagrams prove that the rise in pressure which takes place in the gas engine through the gas exploding at the dead point relatively slowly is not more rapid than that which occurs on the admission of high-pressure steam to the steam cylinder. Mechanical efficiency of a gas engine, about 80 to 85 per cent. Gas engines can be run to within 3 to 4 per cent, of the normal rate. Temperature in cylinder of gas engines, 2,500 F. to 3,000 F. The work expended in compressing gas does not increase pro- portionally with the pressure, but is relatively much less with high pressures. Average gas, 1 to 8 to 12 of air in gas engine. Only 2J times the power is needed to increase a pressure of 10 atmospheres tenfold i.e., to raise it to 100 atmospheres. A good steam engine develops one I.H.P. per kilogramme coal of a calorific power of 8,500 calories. A cubic metre of gas develops 5,300 calories, and one I.H.P. in a gas engine with a thermal duty of 50 per cent, in favour of the gas engine. (Hirsh.) Exhaust pipes from gas engines should have easy bends. At ordinary atmospheric pressure and temperature mixtures of gas and air will not ignite explosively, if at all, when the air amounts to about fourteen times the bulk of a given quantity of gas, and similarly the mixtures will not ignite explosively if too much gas be present. 192 GAS ENGINEER'S POCKET-BOOK. One pound of a mixture of oxygen and coal gas in the proportions required for complete combustion would upon ignition develop about the same energy as 3^ Ibs. of gunpowder. With coal gas at 3*. per 1,000 cubic feet and coal at 15*. per ton the gas engine consuming 20 feet per I.H.P. per hour = a steam engine consuming 9 Ibs. of coal per I. H.P.per hour. (T. L. Millar.) With lighting gas the cost of running large gas engines is about tfce same as for steam engines, lighting gas being much dearer than generator gas for power purposes, especially for engines above 12 H.P. Gas consumption in Dessau tramcars worked by gas engines = 31 -2 cubic feet per mile run. including loss in compression, which is very little. (Herr von Oechelhauser.) Gas Engines for Tramcars. An 8 H.P. engine (Otto type) : charge of compressors = 8 miles supply, cost = Id. per mile for gas. From 4 to 6 gallons water are required per I.H.P. to cool gas engine cylinders. In cooling the cylinders of gas engines 35 per cent, of the thermal units in the gas are lost. Capacity of circulating tanks should equal 23 to 30 gallons per I.H.P. To Find Size of Dry Meter for Gas Engines. Brake horse-power x 3'4 -f- 5 = number of lights. The size of supply pipe to engine can be found by reference to table of meter dimensions. To Find Size of Exhaust Pipe. From 1 to 5 brake horse-power, 1 inch to If inches diameter. Above that size, diameter in inches = 0-528 X H.P. ' 57 . The heat of exhaust pipes is great, and likely to burn wood if too near. Bends of 6 inches or more radius only should be used ; no elbows or tees. Turn the outlet of the pipe to look downwards. To Prevent Excessive Noise in Exhaust Pipe. The pipe can be carried into a drained pit and surrounded with stones, over which a covering of straw can be placed. Quantity of Water Required for Cooling Cylinder. About 5 gallons per I.H.P. per hour if taken direct from mains, and led to under side of jacket at clearance end of cylinder, and removed from upper side at the opposite end. If hard water is used, add a handful of washing soda to tank every month. Circulating Tank's Capacity. Twenty to 30 gallons per I.H.P. with pipes from 1 inch to 3 inches diameter, according to size of engine. The return pipe is usually a little larger than the flow, with a rise of at least 2 inches per foot leading to the tank at the normal water level. GAS ENGINES. 193 Value of Explosive Mixtures. (Dugald Clerk.) Mixture. Maximum Pressure of Explosion above Atmosphere in Ibs. per Square Inch. Time of Explosion. Gas. Air. 1 vol. 13 vols. 52 0-28 second. 1 11 63 0-18 1 9 69 0-13 1 7 89 0-07 1 5 96 0-05 Temperature before explosion, 64 F. Pressure before explosion, atmospheric. Examine the ignition tube occasionally to see that no soot has been deposited by the Bunsen flame. Before starting compress the gas bag and then turn on gas, turning the engine meanwhile to remove the air which may have accumulated in the gaspipes. To stop the engine shut the gas-cock near cylinder not at the meter. The ratio of heat converted into work in a gas engine is greater than in a steam engine. Average heat units lost in the jacket or cooling water, 35 per cent. ,, exhaust, 37 per cent. Otto or Four-Cycle Gas Engines. An explosion takes place every four strokes, or one per double revolution of the crank shaft, viz., piston advances, drawing in the explosive charge ; it then returns, compressing the mixture ; next ignition takes place, the piston is driven forward, and on retiring finally expels the waste products of combustion. The consumption of ordinary illuminating gas in modern gas engines equals from 20 to 26 cubic feet per I.H.P. per hour for moderate to small powers, and for larger powers 18 to as low as 15 cubic feet has been obtained, and with the compound type as low as 10. This, if supplied with Dowson gas, means only '8 Ibs. of coal per I.H.P. per hour. The mechanical efficiency may be taken as from 80 to 85 per cent, at full power, and from 70 to 75 per cent, at half power. Messrs. Crossley state that with town gas at 3*. per 1,000 the working cost of a gas engine of 14 horse-power nominal and up- wards is greater than that of a steam engine. It has been proved that by scavenging the power of a gas engine can be increased 10 per cent., or the consumption of gas reduced, keeping the power the same. With coal gas it is a moot point if the products of combustion hurt the next charge in gas engines. Gas engines are most economical at full power. G.E. O 194 GAS ENGINEER'S POCKET-BOOK. A speed test made with a Moscrop recorder on a single-cylinder double-acting " Kilmarnock " Otto cycle engine showed a variation of 2| per cent, at powers varying from normal full load down to one third. Value of Coal Gas of Different Candle Powers for Motive Power. (C. Hunt.) Candle Power. Consumption Cubic Feet per I.H.P. Relative Value for Motive Power. Relative Value for Lighting. 11-96 30-31 i-ooo 1-000 15-00 24-41 1-241 1-254 17-20 22-70 1-335 1-438 22-85 17-73 1-709 1-910 26-00 16-26 1-864 2-173 29-14 15-00 2-020 2-436 Oil Engines. The oil consumed per hour equals from -7 Ib. with American oil to -86 Ib. with Kussian per indicated horse-power. A Priestman oil engine, using oil above 75 F. flashing point, developed 1 brake horse-power per 1-25 Ib. oil. (W. Anderson.) In a Priestman oil engine tested by Professor Unwin 69 and -86 Ib. oil used per I.H.P. 84 '94 B.H.P. Thermal efficiency 13-31 per cent. Loss of heat in cooling water 47-54 per cent. Mechanical efficiency 82 to 91 per cent. Loss of heat in exhaust gases 26-72 per cent. To find Leaks in connections under Suction. By fixing a small governor on the byepass of the exhauster, weighted to 2 inches, a pressure will be thrown on the plant up to the hydraulic, any leaks showing themselves and explosions prevented. SCRUBBERS AND WASHERS. 195 SCRUBBERS AND WASHERS. Herr Reissner's Rule 5 cubic feet to 6 cubic feet per 1,000 cubic feet per 24 hours of scrubbers. Wyatt's Rule. 100 cubic feet internal capacity of vessels (scrubbers and washers) with a gas contact of from 15 to 27 minutes per ton per diem. Gas in scrubbers should equal 1 per cent, of the maximum daily make to give requisite contact time. Horizontal net sectional area of all the scrubbers is 2 square feet per ton per day maximum make. Capacity of scrubbers should be 15 cubic feet per 1,000 feet of gas per diem, the vessel being one third the diameter of its height. (Kichards.) Another Rule. Scrubbers should be equal to allowing a contact for 10 to 15 minutes of greatest make. Height is an advantage, so that the gas may be easier broken up and wetted surfaces presented. Tower scrubbers usually 6 or 7 times the diameter high. Scrubbers should be cylindrical. Height equal to 6 or 7 times the diameter. Capacity equal to 9 cubic feet per 1,000 cubic feet per diem maximum make. (Herring.) Newbigging's Rule for tower scrubbers, 9 cubic feet per 1,000 cubic feet gas made per day. The washer or scrubber wherein the gas is broken up into small streams passing in contact with wetted surfaces is preferable to that in which the water is divided into small drops and which fall through the gas, as the bulk of the gas is at least 100 times, and more often 1,000 times, that of the liquid. A good scrubber should so distribute the water or liquor that the whole of the surfaces exposed to the gas in its passage should be evenly wetted, with length of contact and such contact ensured. The use of a washer requiring a separate engine must be compared with the extra cost of the fuel required, in one throwing some 3 or 4- inches pressure upon the exhauster. Scrubbers filled with coke will collect tar and cause a lowering of illuminating power by absorption of light-giving hydrocarbons. When coke is used in a tower scrubber a space of 6 inches is usually left above each layer before the next tier of sieves. Average Surface presented to Gas in Scrubbers. When filled with coke . . . *3 or 8| sq. feet per cubic foot. 3-inch drain pipes -54 17 9 fifi 91 55 55 >' ' !) ** >5 J) boards . . TOO 31 Scrubber Boards should be inch thick with f inch or inch space between. Boards 11 inches deep, inch thick, set f inch apart, are used in tower scrubbers with success. o? 196 Ten volumes of water at 60 F. and 30 inches pressure will absorb 7,800 volumes ammonia. 25'3 . sulphuretted hydrogen. 10-0 1-25 37 156 156 156 160 carbonic acid. defiant gas and probably other hydrocarbons, oxygen. carbonic oxide. nitrogen. hydrogen. light carburetted hydrogen. When water has been saturated with one gas and is exposed to the influence of a second it usually allows part of the first absorbed to escape, while an equivalent quantity of the second takes its place. Thus a large volume of an easily soluble gas can be expelled by a small quantity of a difficultly soluble one. (Dr. Frankland.) Liquor distributers sometimes fixed half way up scrubbers where only one scrubber is in use. The whole of the ammonia can be removed from the gas in practical working by using 3 gallons water per ton of coal carbonised, and the quantity of NH 3 per 1,000 cubic feet need not exceed "3 to '4 grains at the outlet of the clean scrubber. Quantity of water required in tower scrubbers from 10 to 18 gallons per 10,000 cubic feet gas made. When more than one washer is used the liquor should be made to flow from the one the gas enters last through to the first, so that the gas meets the stronger liquor first. Provide byepasses to all the different parts of the works. Washers. About 28 gallons of liquor of 10 oz. strength can be obtained from 1 ton Newcastle coal. Reaction of cyanides (Prussian blue) : 6NH 4 CN 4 446 42 3NH 4 Fe(CN) 6 + 2Fe 2 Cl 6 = 3Fe"Cy a ,2Fe'" a Cy 6 orFe 7 Cy 1Q + 12AmCl. Pressure thrown by washers varies from 1 to 4 inches. PURTFIERS. 197 PURIFIERS. In fixing upon size of purifiers note should be taken of the quality of coal likely to be used for manufacturing gas. Some Midland coals produce gas containing nearly double the amount of H 2 S which is to be found in Newcastle coal. Have the purifiers large enough is an excellent rule. Scotch coals produce large quantities C0 2 . Clegg's Rule for Area of Purifiers. 1 foot area per 3,600 cubic feet, maximum make, per diem. Hughe ^ Rule for Area of Purifiers. 1 square yard sieve per 1,000 subio feet, maximum make, per diem. Newbigging's Rule for Area of Purifiers. Maximum daily make x 6 = square feet area each purifier. Newbigging's Rule for Area of Purifiers Connections. Inches, diameter = ^/area of purifiers in feet For large purifiers deduct one-eighth. Beckton practice : 1 square foot of purifier area per 2,500 cubic feet made per diem. Allow, say, 1 square yard of active grid per 1,000 feet of gas per day. Sulphur purification requires for 2,000,000 plant 8 boxes 32 feet x 32 feet X 6 feet deep, with 4 trays for lime and 3 for oxide 1 cubic foo: contents of each purifier per each 376 cubic feet per diem. (A. Colson..) Purifying shed for above, 320 feet x 60 feet. (A. Colson.) Rate of passage of gas through lime purifiers should not exceed 2,000 cubic feet per foot of surface per 24 hours. (G. Anderson.) Purifiers (where lime only is used and no sulphur clauses) should allow a contact of 15 minutes of greatest make, or cubical contents = ^ hour's make, with 5 tiers lime, each 2J inches thick. C. Hunt's Rule for Area of Each Purifier in a series is not less than O'l square foot for every per cent, by volume of the maximum quantity of C0 2 experienced. C0 2 varies from 1 to over 3 per cent. Lime and oxide purifiers when worked in conjunction require from 20 to 30 square feet per ton. (C. Hunt.) G. C. Trewby's Rule. 320 feet for each vessel per 1,000,000 cubic feet of daily manufacture. Four feet area per box per ton of coal carbonised per day with 6 purifiers in the series, 4 for lime and 2 (catch) for oxide. (F. Livesey.) Wyatt's Rule. 100 superficial feet of sieves per ton per day 1,620 cubic feet to house the purifiers with a floor area of 50 square feet per ton per diem, 133 cubic feet total capacity of vessels, gas contact of 15 to 27 minutes, area of covers of purifiers 3 square feet per ton per diem. 198 GAS ENGINEER'S POCKET-BOOK. Lime and oxide sheds : 810 cubic feet of building structure floors area of 25 square feet per ton per diem. Wyatt's Eule. 33 cubic feet or 50 superficial feet per ton per day, contact time 5 to 8 minutes. The useful surface for passage of gas should be rd the volume of the oxide, time of contact 48 seconds, bulk should equal -^th of the gas passed per hour, with 1 layer 24 inches thick ; material showed 15-65 per cent, total sulphur and 11'75 per cent, free sulphur, while with 4 layers each 6 inches thick it showed 14'96 and 9'03 per cent, respectively. (Messrs. Delseaux and Renard.) In the Beckton method of 8 purifiers an area of 0'4 foot per 1,000 cubic feet of gas per vessel is sufficient. (L. T. "Wright.) Allow half a square foot per 1,000 cubic feet maximum daily make for area of each purifier. (Herring.) Purifying surface may range from 1-3 to 4 square feet per 1,000 cubic feet gas per day. Area of each purifier should equal 676 square feet per million per day. Speed of gas through purifiers should be as slow as possible. Herr Eeissner's Eule. Purifiers. Five trays with oxide in each, 1'17 square feet area per-1,000 cubic feet in 24 hours if 4 purifiers, all included in above. Catch purifier with 4 to 6 trays sawdust. Use purifiers of large area : with lime, 2 to 4 tiers of sieves with layer of lime 6 to 9 inches thick ; with oxide, 2 or 3 tiers of sieves with layer of oxide 18 inches deep on each. Purifiers (construction notes). Thickness of cast iron purifier plates should never be less than | inch. The usual width of same f> feet. Flanges of bottom plates should be 2| inches x f inch over and above the thickness of plate. Strong and deep brackets should be fixed under lute, as strain is greatest at this point. (F. S. Cripps.) Cast iron plates for purifiers, if made larger than 5 feet by 5 feet, are liable to twist in casting. Flanges should not be less than 3 inches deep, and thickness about inch to I inch ; plates inch thinner. Depth of water lute in purifiers varies from 12 inches in small purifiers to 30 inches in larger ones ; width from 4J inches to 8 inches. Seals of purifiers should never be less than 18 inches deep. Diameter in inches of pipes in connections to purifiers should equal the square root of area of purifiers in feet. Arrangements of Purifier Connections. (Dempster.) PURIFIER CONNECTIONS. 199 Arrangements of Purifier Connections. (Dempster) continued. F 5 JxM : 1 o-J 0- a i 1 E 3 E ^ r-zs ol C i 01 . 5 21 ol . 9 r tHJ 200 GAS ENGINEER'S POCKET-BOOK. Arrangements of Purifier Connections. (Dempster) continued. Flanges of purifier plates should be planed (not necessarily the whole width, a strip | inch or f inch wide each side and at ends being sufficient), a layer of vulcan cement or red and white lead being put into the joint before it is bolted up. The alternative method is to have a fillet cast on inside of flange and the joint caulked with iron borings and sal-ammoniac and sulphur. It is usual to keep purifiers and gasholders away from retort houses to avoid chances of lighting up at escapes or explosions. Fastenings to purifiers should be strong enough to resist pressure, equal to a column of water the height of the depth of lute, upon the whole area of the cover, the weight of cover causing the gas to blow the water from the lute, CLAUS PROCESS. 201 Valves or ground plugs should be provided for permitting the air to enter while the cover is lifted, and should at least equal one-third the diameter of the connections to the purifiers. Side sheets of purifier covers should be made thicker than the top sheets, as the level of the surface of the water is where the plates will first rust. Crown sheets may be of No. 12 Birmingham wire gauge. Purifiers in the open can be kept warm in winter by the use of hay or straw, and cool in summer by spraying water over the covers. If the top of the purifiers are kept 18 inches above ground the material can be easily removed and wheeled in. Lifting of purifiers is best done by straps at the sides of the covers. Purifier sieves usually made 2 inches thick with f-inch taper deal bars, and distance blocks, oak side strips 1 inch by 2 inches, and fastened by f-inch bolts or rivets. Usual thickness of layers. Oxide, 2 feet 6 inches deep ; lime, 1 foot deep. About 701bs. quicklime will remove C0 2 per 1 ton coal. Oxide heated to 70 C. revivifies easier. Lime should be sulphided below 40 F. 135 gallons water required per cubic yard dry lime, making 2\ yards slaked material. One cubic yard kiln lime weighs 11 cwts. Mr. W. King has erected a purifier house without valves U tubes, which can be filled with water to prevent the passage of the gas, being used. The Glaus Ammonia Process of Purification. The gas, having passed through a tar extractor, is then passed through several scrubbers filled with broken ganister bricks, and here meets ammonia gas, and in the first two scrubbers ammoniacal liquor freed from C0 2 and H 2 S, the gas being entirely freed in its passage from C0 2 and H 2 S. while of ammonia there remains at the outlet of the last scrubber only the usual faint traces, and the bisulphide of carbon is reduced by from 20 to 70 per cent. Arrangements are made that in 5 towers the scrubber liquor is heated to a carefully regulated temperature for the purpose of driving off the CO 2 and H 2 S with as little loss as possible of ammonia. It is then passed through 3 more towers, in the second of which it is exposed to free steam, which deprives it of all traces of C0 2 and H 2 S, and also of all ammonia, except what may be present as fixed in the form of sulphocyanide of ammonium ; in the third tower the hot vapours (187) are condensed .to 120 or less, and are then ready for use again to remove the impurities. All the sulphur gases driven off from the liquor are deposited in a chamber in the form of pure sulphur, equal to from 10 Ibs. to 141bs. per ton of coal used. 202 GAS ENGINEER'S POCKET-BOOK. GASHOLDER TANKS. As a general rule the bearing capacity of grou the surface is greater than at the surface itself, but in all cases bore- holes should be made to see that the solid ground upon which it is proposed to lay the bottom of the tank is fairly level, and that it is of sufficient depth. In some cases the strata of, say, ballast, which would safely carry the tank walls, &c., have been cut through, or nearly so, and when the tank has been completed the level of the walls has varied considerably. The larger the number of the borings taken around a proposed gas- holder tank site the better to ensure that the foundation is level and equally weight-resisting. If any doubts exist as to the solidity of the ground where the tank is proposed to be placed it is better to put up an iron or steel one, which may be made to rest on piles and cross timbers. It is often better to raise the level of the wall of the tank when water is found in the subsoil which may afterwards injure the nature of the foundation. For tanks up to 36 feet deep and inside diameters of 150 feet : ith the depth of tank = thickness of concrete walls, ith = piers, ith = width of piers. (Wyatt, 30th April, 1889.) The well or sump which is sunk before commencing a tank may be lined with steining (open brickwork without mortar), or merely timbered with stout timbers if it is proposed to fill up the sump when the tank is completed. In some cases large pipes (cast iron) have been let in as the excavation proceeded, without jointing, and thus formed an excellent backing to prevent the sides falling in. The sump should be at least 3 to 5 feet deeper than the lowest part of the excavation to be made for the tank ; often a considerable amount deeper will lessen the after expense with tanks in bad ground. Sometimes more than one sump is found necessary, or drain pipes have to be laid to convey the water to the pumps, which should always be in duplicate. Natural Slopes of Earths with the Horizontal Line or Angles of Repose. Gravel average 40 degrees or 1*2 to Dry sand average 38 or 1-30 to Sand average 22 or 0'27 to Vegetable earth average ... 28 or 1-89 to Compact earth average . . . . 50 or 0'7 to Shingle average 39 or 1-25 to Rubble average . c . . . 45 or 1-0 to Clay, well dried, average . . .45 or 1-0 to Clay, wet, average . . . . . 16 or 8-3 to Peat average 28 or 1 '89 to 1 GASHOLDER TANKS. 203 General Tank Notes. An Iron or Steel Tank saves excavation and expenditure on foundations in many cases. Steel tanks should be well grouted in, in many places, when lowered on to their bed. Steel tanks require more maintenance than stone or brick ones, and more steam for preventing freezing of the water during frosty weather. Cost of a steel tank usually one-half to two-thirds that of an excavated brick or concrete one. Cost of steel tanks about 3'3d. to 3'7d. per cubic foot capacity. Cost of brickwork tanks about 4'4d. to 5'9d. per cubic foot capacity. The plates in the bottom row of a 50 feet deep X 190 feet diameter tank have been made If inch thick X 4 feet 4 inches wide X 24 feet 9 inches long. It is usual to put the flanges of cast iron tank bottom plates inside and the flanges of the side plates outside. Tanks may with advantage be left large enough to allow of an extra lift when being first designed and laid out, although it may not be at the moment required. The larger the volume of water in a tank the less the liability to freeze. Thickness of Tank Walls at any point in inches = Pressure of water (pounds per square inch) X radius of tank in inches Cohesive force of wall in pounds per square inch - pressure of water. Force of water tending to burst a tank outwards = 62'5 x diameter of tank x (depth). Pressure on wall of tank due to earth backing therefore equals resistance of earth X outside diameter of tank X (depth 2 ). Resistance of the weight of wall equals half the cubic contents of the wall in feet X weight of 1 cubic foot of the wall. Resistance of the cohesion of the material of the wall equals cohesive force X height 2 x average thickness of wall. Cohesive force of bricks in cement 1 (cement to 3 sand) equal to 31,680 Ibs. per square foot. Resistance of earth backing dry equal to \ an equal column of water. (Sir B. Baker.) Resistance of earth backing, water-logged, equal to 1^ an equal column of water. (Sir B. Baker.) Resistance of earth backing, clay or earth, equal to 1,200 Ibs. per square foot. (Newbigging.) 204 GAS ENGINEER'S POCKET-BOOK. Ultimate Resistance of Loam Earth per Square Foot in Ibs. E. A. Tests. Mean Depth of Anchorage below Inclination of Force drawing the Anchorage (in a Direction perpendicular to its Face). Surface. Vertical. 1 i * i 1 foot 808 933 1,244 1,300 1,430 1 foot 6 inches . . 1,040 1,458 2.100 2,180 2,360 2 feet 1,925 2,700 3,880 4,032 4,370 3 feet .... 3,024 4,400 5.860 6,160 6,750 4 feet 5,470 8,000 10,660 11,200 12,260 5 feet .... 14,112 22,000 29.330 30,800 33,730 In damp sand the resistance would be half that in earth. A factor of safety in tank walls of 3 is ample. Resistance of Different Earths to Horizontal Compression. (M. Arson.) Sand 2.050 Ibs. per square foot. White tufa (a light stony powder) 1,640 ., ., Vegetable earth mixed with gravel 900 The earths were well watered and punned. The Backing to Gasholder Tank Walls should be well punned and watered to cause it to have direct pressure upon the wall, as cracks are almost invariably found in a vertical direction and only open a very slight distance, which would suggest that the walls have then taken up the support of the backing. Clay has often been known to sustain a pressure of water of 15 Ibs. per square inch, or about 1 ton per square foot. One cubic yard* puddle weighs about 2 tons. Puddle may be thrown from a height of 20 feet with advantage, but should not be laid in layers of more than 10 inches at a tine. Where clay is to be found upon the site it will probably be cheaper to construct a puddle tank than a rendered one. Fuddle. Work the clay well up with water to break up the original formation, and bring about a new arrangement of the particles, adding sufficient water to fill up every pore. If possible, expose the clay before tempering for a considerable time to the air. It should be opaque, not crystallised, with a dull earthy fracture, and exhale an argillaceous smell. Tenacity and power to retain water is the principal requirement. If a roll well worked up by hand to eight or ten times its thickness be suspended, while wet, by one end it should not break. It should retain its original quantity of water when formed into a basin and filled for 24 hours, if covered up to prevent evaporation. (W. Gallon.) Puddle should be put in in layers of not more than one foot, and should be thrown in with force to cause it to adhere to that already in. The top of the puddle should be carefully covered when any dirt is being put in to form a backing, as any grit in the puddle may cause a leak, owing to the grit preventing a thorough adherence of the two layers of puddle. TANK WALLS. 205 Puddle should be laid over the whole of the surface of the dumpling and connected all round to that under and on the outside of the wall without any break. Brick tanks with f inch cement (neat), in two coats, can be made without puddle, and will prove quite tight. Should a leak show itself when the pumping has stopped for testing the soundness of the tanks stock-ramming may be employed to fill up the space where the leak occurs. In doing this a hole is first cut in the wall or floor of the tank and a pipe inserted down to the puddle level, and then cartridges of clay are put in the pipe and forced down with rammers. These latter are frequently made with the heads so that several men can use their strength to ram the clay well into the hole. In puddled tanks the pressure of the water is thrown upon the puddle and earth backing, and not upon the wall itself, while with a cement-rendered tank the pressure is upon the wall. Hoop iron or thicker wrought iron bands are often imbedded in the cement of a tank wall, and considerably add to the strength. They should be bent round and turned back at the ends, and laid so that they hook one into the other and form a continuous band. Where no backing is used to help Tank Sides to resist the pressure of Water the thickness of the Cylinder may be calculated as follows : When the thickness is less than g^th the radius the thickness = Pressure in Ibs per square inch - ; - -r-. - : - X radius m inches. Safe strength in Ibs. per square inch This regards the material as only subjected to tensile strain. To find the Thickness at base of Wall to resist the overturning with the pressure of quiet water level with its top and no backing (wall with vertical back and sloping face) : Thickness of base at foot = (Hf 2 ft. x factor of safety*) + (batter ^Tt. x sp. gr. of wall) 3 X sp. gr. of wall. Eequired moment of stability of wall *Factor of safety = V> * - Overturning moment of water. Where cylindrical hoops are placed around tanks, to find the distance apart at which they should be fixed to each to sustain the same strain Fix upon the number of straps required then for the first, fjl X total No. of straps X depth of tank Total No. of straps = Distance from top of tank for 1st strap. For the second strap, ^/ 2 x total No. of straps X depth of tank Total No. of straps. = Distance from top of tank for 2nd strap. And so on for each strap, substituting for the 1 and 2 in above formulas the number of the strap from the top. /( 206 GAS ENGINEER'S POCKET-BOOK. To find the Pressure of Water against a Tank Side. Multiply the vertical depth in feet of its centre of gravity below the surface of the water X the area of surface pressed in square feet X 62'5 = pressure in Ibs. The pressure of liquids being always perpendicular to the surface at any point, if the wall be vertical the pressure is horizontal. The centre of pressure is always one third of the vertical depth from the bottom. Table showing the Pressure in Ibs. per Square Foot, and Pressure against a Plane 1 Foot Wide from Top to those Depths. Depth in Feet. Pressure per Square Foot. Pressure on Plane. Depth in Feet. Pressure per Square Foot. Pressure on Plane. 1 62 31 26 1,625 21,125 2 125 125 27 1,687 22,781 3 187 281 28 1,750 24,500 4 250 500 29 1,812 26,281 5 312 781 30 1,875 28,125 6 375 1,125 31 1,937 30,031 7 437 1,531 32 2,000 32,000 8 500 2,000 33 2,062 34,031 9 562 2,531 34 2,125 36,125 10 625 3,125 35 2,187 38.281 11 687 3,781 36 2,250 40^00 12 750 4,500 37 2,312 42,781 13 812 5,281 38 2,375 45,125 14 875 6,125 39 2,437 47,531 15 937 7,031 40 2,500 50,000 16 ,000 8,000 41 2,562 52,531 17 ,062 9,031 42 2,625 55,125 18 ,125 10,125 43 2,687 57,781 19 ,187 11,281 44 2,750 60,500 20 ,250 12,500 45 2,812 63,281 21 ,312 13,781 46 2,875 66,125 22 ,375 15,125 47 2.937 69,031 23 ,437 16,531 48 3,000 72,000 24 ,500 18,000 49 3,062 75,031 25 1,562 19,531 50 3,125 78,125 When water is pressing on each side of a wall at different levels the pressure at any point can be found by setting off at, say, each foot depth the pressure on the wall due to the one height of water and upon the other side the pressure due to the other height. Deducting the lesser pressure from the greater gives the pressure upon the wall. Example. A wall 10 feet long has water to its full height, 5 feet on one side and 3 feet high on the other ; the pressures are as shown in fig. on next page. The excess of pressure on the high water side is always equal to the pressure on that portion 9f it at the low water level. TANK WALLS. 207 In calculating the strength of Tank Walls the tank may be supposed to break in two halves upon the axis of the cylinder ; the force tending to open the two halves is the pressure of the water, and the opposing forces are the backing, the cohesive nature of the material in the wall, arid the weight of the masonry. The overturning moment of the water in Ibs. = 62'5 X diameter of tank X de P th of tank3 6 The moment of resistance of the earth backing = constant X depth of tank 2 external diameter of wall X Moment of resistance of the weight of the masonry = 112 X thickness of walls 2 X external diameter of walls x depth of tank 2 Moment of resistance due to cohesion = 30,700 X depth of tank 2 X thickness of walls. Dimensions all in feet. Pressure due to Head of Water may compress the earth left in to form dumpling in tank and cause leakage. See resistance of earths to pressures, page 204. Iron bands are inserted in the concrete at East Greenwich tank of 5 inches X ^ i nc ^ na ^ iron, riveted to form complete rings, and placed 2 feet apart vertically. A Water-tight Concrete can be made when two volumes of sand are added to one of Portland cement, ground fine enough to allow nine- tenths to pass through a sieve with 14,400 meshes in each square inch. A coarser cement passing only three-fourths through the same sieve will not make a water- tight concrete when mixed with only one and a half times its volume of sand. 208 GAS ENGINEER'S POCKET-BOOK. Thickness of Sheets of Wrought Iron for Tanks of Different Diameters and Depths. Factor of safety, |th. Deduction for rivet holes, 40 per cent. 20 30 40 Depth in feet. CONCRETE TANK WALLS. 209 When the first batch of concrete is mixed, the quantity of water per bushel of dry materials should be noted, and the same propor- tions held to with the other batches, uniformity in this respect being of the utmost importance. As much water should be added as will give a mixture that allows a man treading over it to sink in to a depth of at least 6 inches. No stones used for concrete should be larger than will pass through a mesh 2 inches square. Concrete should not be dropped or made to slide down a shoot, and inferen- tially it should be laid with a spade without a fall of any kind, and then it requires to be trodden down. Stout bars of flat iron laid into the walls of a concrete tank, and hooked together to form a complete ring on edge are said to give great strength to the same. The expansion of iron and cement con- crete being nearly equal prevents fracture between the two materials. Firebrick rubbish and furnace clinkers form with sand or sharp grit excellent material for concrete. Concrete composed of 1 part cement to 10 or 12 coke breeze is porous. A good coat of asphalt will render a tank quite water-tight. A coating of hot asphalt and tar is also used to render cement tanks water-tight. Rendering is usually done with equal parts Portland cement and sand, arid laid on from inch to f inch thick, with a final layer of neat cement carefully trowelled on about inch thick. French engineers usually specify a much greater thickness of cement and sand in equal parts, without the neat cement layer. Portland cement rendering usually made of 1 cement to 3 of well washed sand. External mouldings and linings to water tanks neat cement. A simple Rule to avoid loss in Cupping is, when constructing, to make the tank measured from the rest-stones the full depth of the various lifts, plus a depth equal to the difference between the dis- placement of the inner and outer lifts, and add a margin of 3 inches. Pumps for gasholders should be made with an outer casing to the bottom of the pipes to be pumped, so that the pump may be removed for repairs without an escape of gas. Tank, 114 feet x 31 feet deep, at Wellingborough, made with Portland cement concrete 7 to 1, and puddled at back, no rendering, concrete over dumpling (of clay) 6 inches thick. Wall of tank 123 feet diameter x 30 feet deep = 3 feet 6 inches thick at bottom to 2 feet thick at top. A cast iron tank 112 feet diameter X 25 feet deep has been erected, weighing about 500 tons. Concrete made with clinkers ana broken firebricks and retorts said to be stronger in tension than if made all Thames ballast. thickness of Sheets of Brought Iron for Tanks. = P ressurein f . Ibs -P e 7q uareinch x radius in inches sate strength See diagram opposite. G.E. P 210 GAS ENGINEER'S POCKET-BOOK. GASHOLDERS. General Notes. Mr. G-. Livesey stated (1882) that 201. per 1,000 cubic foot capacity was a usual cost of gasholders of moderate size. Two holders of about equal size should be provided in all works. When extending, holder capacity should be doubled by the addition of one holder of equal capacity to all the previous ones combined. Single lift holders should not be usea except for less than 10,000 cubic feet capacity. Height of lift should = Holders above 500,000 cubic feet capacity should be three lifts. When weight is required to give necessary pressure increase the thickness of sheets and cups. No necessity to break joint in side sheets, as load is much below the strength of the sheets. It should be borne in mind that 'the larger the sheets the less rivets are required, and the liability to leakage is reduced. The strain on top sheets diminishes in exact proportion to the rise, and is uniform throughout the top sheets. Usual rise = 20 Shapeof dome equals segment of a sphere. With rise = diameter , No. 11 Birmingham wire gauge sheets are 20 sufficient up to, say, 175 feet diameter, but when larger, No. 10 sheets and an increased rise would be better. Rivets ^ inches diameter. The crown curb in trussed holders has not much work to do. The best form of curb is an angle iron or steel, but in larger holders where the compressing strain may equal 200 tons other pattern curbs must be adopted. Mr. Livesey considers 40 Ibs. per foot as the maximum wind force likely to be exerted on a gasholder ; and 57 per cent, of this force is exerted on the cylinder as compared with a flat surface. When diagonal bracing of sufficient strength is in use, the side strength of the columns or posts need not be great as the strain is resisted by the bracing. For moderate sized gasholders. Mr. G. Livesey and Mr. C. Hunt prefer cast iron columns. Theoretically if pressure is brought upon a cylinder it tends to expand it in all directions. In a gasholder at New Jersey, U.S.A., which overturned in a gale, all the columns but one fell outwards. Mr. Foulis considers 50 Ibs. per square foot should be allowed for as wind pressure on gasholders. Mr. Cripps suggests gussets to connect the first row of top sheets with the top row of side sheets in small holders. NOTES ON GASHOLDERS. 211 To find the strain on top sheets 18-3 Weight of side sheets in tons = gtrain angle of top in degrees (Half diameter of holder 2 + rise 2 ) X effective pressure of gas X diameter of holder in feet g . ^ 8 X rise It is essential that gasholders should be maintained perfectly level. The Old Kent Road type of gasholder "is one of that class of structures in which it is impossible to foresee the exact intensity and nature of the stresses." (Sir B. Baker.) Steel curbs are better than iron as they stand a higher compressive strain. Two angles, one set at each end of the first and thicker row of top sheets, is the easiest and simplest method of constructing a curb where considerable strain has to be resisted, as each inch of section is profitably utilised. Radial rollers spread the wind pressure on one quarter of the guides. Tangential rollers spread the wind pressure on one half of the guides. The two combined spread the wind pressure on three quarters of the guides. Mr. Webber considers the two combined spread the wind pressure on two-thirds of the guides. With tangential, or these combined with radial rollers, the pressure from the curb is better distributed, and the strain upon the guides is thrown in a tangential direction, thereby bringing the diagonal bracing directly into use in the position it is best able to resist the strain. Stays to inner lifts of gasholders are usually made of T iron trussed, but in large holders channel and H iron frequently take the place of the T. Channel iron forms, on the outer lifts, both a stay and also a guide path for the next inner lift roller. Vertical stiffeners require securely fastening to cups and grips. Vertical rows of thicker section* plate are not advisable, as the riveting to the next rows on either side is not so tight. Sometimes the stiffeners are riveted to the side sheets by rivets at very close pitch, sometimes at 1 foot apart, and at others only attached to cup and grip. Gasholder sheets should never be allowed to oxidise, but receive a coat of boiled oil immediately they are planished and punched. An average gasholder contains more than 40 feet run of riveting and joint per 100 cubic feet. It is not considered advisable to rivet crown sheets to trussing in holders, as it prevents the sheeting ballooning out into a spherical shape, and throws great strain on the rivets. (Cripps. ) P2 212 GAS ENGINEER'S POCKET-BOOK. Weight of bell of holder is almost equal to that of the guide framing in wrought iron or steel. All rivets should be well brought up with the set, firmly held and properly riveted, if a sound job is to be secured. All holders should be well painted every year. Wyatt says about 20 Ibs. weight of wrought iron is used per superficial foot of sheeting (inclusive of the guide framing). Of this 12 Ibs. is the holder proper and 8 Ibs. the framing. (October, 1887.) Side sheets vary in thickness from No. 11 in large holders to 17 Birmingham wire gauge in small ones. The depth of each lift must never be less than ith of the diameter of the holder ; and it will work better if it be Jth or |th the diameter. With holders up to 120 feet diameter, it is cheaper to put in a light trussing than to place a wooden framing in the tank ; but above this size it is more economical to put a timber framing to receive the holder when down. The trussing of a gasholder should never be more than 10 to 12 per cent, of the floating weight. (Cripps.) Useless weight due to trussing of holders may cause an increase ot 10 to 12 per cent, in the fuel account of the boiler supplying steam to the exhauster engine. Large single lift gasholders are often made so light that weights are required to cause them to throw sufficient pressure. In this case water troughs should be employed so that the water can be run in at night when pressure is required, and the back pressure in works relieved during the day in running off the water. Mr. C. Hunt prefers cast iron columns for holders of moderate size, as a cast iron column is cheap and easy to construct. It has been proposed to carry the pipe from the meter to the governor house, and there connect it by a valve to the town mains before leading it to the gasholders, so that in case of a stoppage at the gasholders it can be at once turned on direct into the town, a governor being used to give warning of the necessity of turning on the valve. Bivets Bequired to Join Different Thickness Plates in Gasholder Construction. (C. and W. Walker.) | inch to | inch require $ inch rivets at 2 inches pitch. " " 2| ," " M 2 ,- 4 .. ., 1 inch ,, ,, If inches .. ;; ;, 11 1 1 1 n f " i f ?? i ,. 10 B.W.G. 10 B.W.G. 10 B.W.G. 10 B.W.G. ^ inch tinch ra n f Riveting (single) to No. 11 plates (double) = 3 Uh weight of plates. = Ath (single) | inch plates 1 inch pitch = (double) = STRAINS ON CROWNS. 213 Biveting to irons 2 inches to 6 inches pitch average $th'of weight of plates. Not possible to join a thin plate to a thick one and make a gas- tight joint, therefore the second plate from curb should be half way between outer plate and crown sheeting in thickness. Reduce the thickness of sheets gradually to ensure tightness. Always rivet a thin sheet to a thick one, not the thick to the thin. Allowance for lap of plates When the lap equals 1 inches add ^ inch or 7 per cent, (no rivets). Allowance for waste on rivets, 10 per cent. for rivets, bolts, and laps over and above plates to $. Expansion of cast iron 100 feet long = f inch for 100 F. (Horton.) wrought iron =^ 100 F. copper ' =1-28,, 100 F. Iron expands with tension and contracts with compression i^th Of its length per ton per square inch. (Cripps.) Table showing the Strains on a Holder 200 feet diameter, with Different Rises of Crown, (V. Wyatt.) Rise of Crown of Holder in Feet. Surface of Domeequals 6-2832 R. V. SquareFeet. Ratios of Dome to Plane Sur- face Area. Radius of Dome. Tension on of Dome. Tension on 1 Foot in Length of Dome. Compres- sion on One Sec- tion of Top Curb. 31416 I'OOOO 10 31730 1-0100 505 528* 3-40 331 15 32091 1-0214 340 348 2-20 213 20 32672 1-0400 260 272 1-80 161 25 33300 1-0600 212 222 1-40 126 40 36442 1-1600 145 151 0-96 70 50 39250 1-2500 125 131 0-83 51 100 62832 2-0000 100 104 0-67 00 Doubling the rise of the crown reduces the strain on the top sheeting one half ; here it is well to break joints as strength is required, and 96 per cent of the plates can be ordinary square sheets. Strain being equal on all crown sheets, they should be of equal thickness. diameter Radiating strips are unnecessary. Usual rise of crown = in the form of a segment of a sphere, in this case No. 11 gauge sheets are sufficient for gasholders of moderate size, but for 200 feet diameter holders No. 10 gauge sheets better and larger rise. Rivets in crown sheets should be ^ inch diameter. Trussed holders require only moderate curbs. Cheapest (and easiest and simplest to construct) curb, is two angles of iron or steel, one at each end of a flat plate. 214 GAS ENGINEER'S POCKET-BOOK. Messrs. C. and W. Walker construct all their holders to one curve for ithe top, which is an arc of a circle 405 feet radius, but for holders under 50 feet diameter give them a greater rise than this. Strain on crown sheeting varies almost inversely as the rise. Rise of crown sometimes made '875 of an inch per foot in diameter, which is the form it would take with a bursting pressure. It has been suggested that a radius of 400 feet for gasholder crowns should be used, as inch sheets are then strained to what they will safely bear in most gasholders. Pressure of snow may cause a load of 5 Ibs. per square foot over th the area of a holder, and the centre of gravity may be (say) th diameter from edge. (F. S. Cripps.) 1 cubic foot fresh snow 5 to 12 Ibs. . . Trautwine. 1 snow compacted by rain 15 to 50 Ibs. Weight of gasholder bell equals weight of 1 cubic foot water X area on water line in feet X pressure thrown in feet, or, Area X 5-2083 = Ibs. per inch pressure. (F. S. Cripps.) Equilibration chains to gasholders. Formula for required weight of chains : w = weight of 1 foot vertical of gasholder in Ibs. G = specific gravity of iron in ditto. W = weight of 1 foot of chain in Ibs. N = number of chains. To find the weight of a gasholder W = weight in Ibs. A = area of water surface in sq. ft. p = pressure in inches thrown. then, W = A To find pressure of a gasholder : W = weight in tons. d = diameter in feet. p = pressure in inches. 547 W FORCE OF THE WIND. 215 Force of the Wind. Velocity. Force. Miles per Hour. Feet per Second. Lbs. per Square Foot. 1 1-47 005 Hardly perceptible. 2 2-93 012 3 4-40 044 Just perceptible. 4 5-87 048 5 7-33 123 Gentle pleasant breeze. 10-0 229 10 14-67 300 Pleasant brisk gale. 20-0 915 15 22-0 1-107 20 29-34 1-968 30-0 2-059 25 36-67 3-075 Very brisk gale. 40-0 3-660 30 44-01 4-429 50-0 5-718 35 51-34 6-027 High winds. 40 58-68 7-873 60-0 8-234 Hard gale. 70-0 11-207 50 73-35 12-300 Very high winds. 80-0 14-638 60 88-12 17-715 A storm. 90-0 18-526 100-0 110-0 22-872 27-675 A great storm. 80 117-36 31-490 A hurricane. 120-0 32-926 130-0 38-654 90 132-02 39-852 140-0 44-830 100 146-7 49-200 150-0 51-462 120 176-04 70-860 216 GAS ENGINEER'S POCKET-BOOK. Velocity and Pressure of Wind. (Another Rule.) Miles Hour. Feet per Second. Lbs. pei- Square Fcot. Miles per tlour. Feet per Second. Lbs. per Square Foot. Miles per Hour. Feet per Second. Lbs. per Square Foot. 1 1-46 0-005 18 26-40 1-620 35 51-33 6-125 2 2-93 0-020 19 27-86 1-805 36 52-80 6-480 S 4-40 0-045 20 29-33 2-000 37 54-26 6-845 4 5-86 0-080 21 30-80 2-205 38 55-73 7-220 5 7-33 0-125 22 32-26 2-420 39 57-20 7-605 6 8-80 0-160 23 33-73 2-645 40 58-66 8-000 7 10-26 0-245 24 35-20 2-880 41 60-13 8-405 8 11-73 0-320 25 36-66 3-125 42 61-60 8-820 9 13-20 0-405 26 38-13 3-380 43 63-06 9-245 10 14-66 0-500 27 39-60 3-645 44 64-53 9-680 11 16-13 0-605 28 41-06 3-920 45 66-00 10-125 12 17-60 0-720 29 42-53 4-205 46 67-46 10-580 13 19-06 0-845 30 44-00 4-500 47 68-93 11-045 14 20-53 0-980 31 45-46 4-805 48 70-40 11-520 15 22-00 1-125 32 46-93 5-140 49 71-86 12-005 16 23-46 1-280 33 48-40 5-445 50 73-33 12-500 17 24-93 1-445 34 49-86 5-780 60 88-00 18-000 Formula for obtaining the Velocity of High Winds from the Pressure. Velocity = V 10 X pressure. Formula for obtaining the Pressure of High Winds from the Velocity. A maximum wind pressure of 56 pounds per square foot is recom- mended in calculations for railway bridges and viaducts. Greatest pressure of wind recorded in pounds per square foot at : Aberdeen . 41 Liverpool Armagh . . 27 London . Birmingham . . 27 Valentia Edinburgh . 35 Yarmouth Falmouth . 53-7 Brussels Glasgow . . 47 Paris Greenwich . 42 Bombay Halifax . . 30-2 Calcutta . Holyhead . 64 Madras . Kew . 27 90 20-2 65-6 42-2 22 17 38 40 34 WIND PRESSURES. 217 Allowance for Wind and Snow. Weight of snow on horizontal surface = say 15*5 Ibs. per square foot. Wind pressure on surface at right ) 9 ,. fi 1K angles to line of impact ' I ' Wind pressure on surface in spe- ) Q1 .n IK* cially exposed positions I ~ dl ' bs ' " (D. K. Clark.) According to returns' from the Greenwich Observatory during 20 years the greatest pressure equal to 28 Ibs. per square foot from the west. Velocity of the wind (feet per second) squared x -002283 = Ibs. pressure per square foot. At the Eiffel Tower it was found that the wind was 3 times as strong at 303 metres from the ground as it was at 21 metres, the velocity at the higher level in summer exceeding 8 metres per second during 39 per cent, of the time and 10 metres per second during 21 per cent. Observations at the Eiffel Tower show an increase of 33 per cent, in velocity and pressure of wind per 100 feet in height. Within certain limits the intensity of wind-pressure increases with the area of the receiving surface ; but over large areas the maximum is not reached in practice, owing to the wind moving in concentrated gusts. In designing structures, although 56 Ibs. per square foot might be looked upon as the standard, this should be modified according to the circumstances of the case, viz.: with the height from ground level, the unsupported width, and the angle of incidence. Pressures, according to received tables, varied from 16 Ibs. at ground level, to 80 Ibs. at a height of 200 feet ; and, in the latter case, from 80 Ibs. at a width of 10 feet to 40 Ibs. at a width of 1,000 feet, while the multiplier for angle varied from 0'45 at 5 degrees to TOO at 60 to 90 degrees. (Professor Adams.) Sir G. Stokes recommends that the rate of travel of cup anemometer should be multiplied by 2-4 instead of 3 to get the velocity, and that velocity 2 x 0'0035 should equal pressure instead of velocity 2 x 0'005. Maximum wind pressure usually allowed = O'Ol v 2 ; ^ = velocity of wind by cup anemometer. In France velocity of storms is taken at 100 miles per hour, and pressures up to 60 Ibs. per square foot over the effective area of 1 truss of a solid truss bridge, or T5 trusses of an open trussed bridge. In America wind pressures of 30 Ibs. per square foot are allowed on large surfaces and from 40 to 50 Ibs. per square foot on small surfaces. Velocity of high winds = VlO v 360 x No . of columns = sectional area required. 24 x depth 2 + diameter 2 For wrot. iron. g n 11 6 24 125,000 1,250 15 4 15 16 6 14 12 4 24 150,000 1,500 15 6 17 6 15 5 13 6 14 2 24 250,000 2,500 20 6 19 3 21 18 15 30 Round Station Meters. Capacity per Hour. Capacity per Revolution. Diameter Inside. Depth Inside. Diameter of Flanges. Diameter of Con- ; nections. Ft. Ins. Ft. Ins. Ft. Ins. Inches. 600 5 2 3 2 3 2 9 2 900 7-5 2 10 2 3 3 4 3 1,200 10 3 2 2 8 3 8 3 1,500 12-5 3 4 3 3 10 4 1,800 15 3 6 3 4 4 4 2,400 20 3 9 3 6 4 Bi 4 3,000 25 4 4 4 7 5 3,600 30 4 3 4 2 4 10 6 4,000 40 4 9 4 6 5 4 6 5,000 50 5 4 8 5 7 6 6,000 60 5 5 4 5 7 8 7,000 70 5 6 5 6 6 1 8 8,000 80 5 10 5 8 6 5 8 10,000 100 6 4 6 2 6 11 9 12,500 125 6 10 6 2 7 5 10 15,000 150 7 7 10 7 7 10 17,500 175 7 3 7 6 7 10 12 20;000 200 8 7 6 8 7 12 25,000 250 8 9 6 8 7 12 30,000 300 8 5 9 8 9 14 MANUFACTURING. 231 STORING MATERIALS. Coal when exposed to the air changes m character, the change consisting in a diminution of agglomerating as well as of lighting power, and probably also of heating power. The change is more rapid the higher the temperature and the more divided the coal. In the small pieces the change in the character of the coal is greater on the surface than in the interior. In heaps of coal per- meated by the air the change is greater in the centre than on the surface. When the air cannot penetrate to the centre the surface undergoes the greatest change. Small coal washed is less liable to change than unwashed. Large pieces of coal are only liable to change after a certain number of years' exposure to the air. The small coal is affected very quickly if it happens to be under conditions likely to raise its temperature. In a few months it is capable of entirely losing its agglomerating and lighting power. Heaps of small coal become heated, but stacks of large coal do not heat to an appreciable degree. Small coal should not be stacked in too large heaps. Coal stacked in low heaps does not become heated. Heat increases with the height of the stack, and at about the height of 3 or 4 metres the temperature rises progressively and then descends without having exceeded 60 C. or 70 C. The inner temperature of a stack 2 metres high does not usually exceed 40 C. to 50 C. (M. de Lachomette.) Storing coal in the open may cause a loss of from 30 to 40 per cent, in the quantity of gas to be obtained from it. North Wales coals and certain cannels are said not to depreciate appreciably through exposure when stored in the open, while certain Scotch coals have been known to lose 50 per cent, in value in 3 months. All coals exposed to the air absorb oxygen, the volume of which may be 100 times that of the coal. The loss and increase of weight are produced more slowly the larger the pieces of coal. (M. de Lachomette.) The yield of gas from coal before exposure being equal to 26*36, fell to 6-60 after being subjected for 4 days to 400 C., and at 8 days to nil. The illuminating power also diminishing very quickly. (M. de Lachomette.) Powdered coal containing from 1*6 to 8'3 per cent, oxygen when subjected to the prolonged action of air and of stagnant and running water is not appreciably affected with regard to composition, yield of coke, or calorific power. (M. Georges Arth.) The drier the coal when stacked the less the liability to heat, and all trampling or compression should be avoided. The only thing to be done with heated coal is to open it out and allow it to cool, or the heating will spread. M. Morin suggests connecting the two ends of a thin platinum wire, about 0-0008 inch diameter, laid through the thermometer to a 232 GAS battery and galvanometer, when the varying resistance due to the rise and fall of the mercury will be shown upon the galvanometer, and the temperature of anything may be observed at a distance, such as in a heap of coals. Another form of indicator for showing when coals are heated above a certain temperature might be made by means of the two wires from a battery covered with gutta-percha and the one wound round the other, so that when a sufficient heat was formed to melt the covering the two wires would be in contact, and could be made to Aug an electric bell. Igniting Points of Coals. (V. B. Lewes.) Cannel . . . 098 F. = 370 C. Hartlepool . . . 760 ., = 408 Lignite . . . 842 == 450 Welsh steam . . . 870J = 477 When Wire Ropes have to run over small pulleys or capstans the number of wires should be increased. In the case of cranes sometimes as many as 270 are used. Average consumption of Coal per Passenger Train Mile equals 30 Ibs., or about 1 Ib. to If Ib. for hauling 10 tons 1 mile. Consumption of coal per square foot of firegrate per hour varies from 60 Ibs. to 80 Ibs. When large Stocks of Coke are stored in the open an increase in weight of 15 to 20 per cent., due to wet weather, has at times been found. (C. Gandon, Gas Institute. 1887.) See also p. 145. Stacking coke in large quantities deteriorates the quality. 100 Ibs. coke can absorb 50 Ibs. water. Increased quantity of breeze due to use of coke breaker only about 5 per cent, of coke broken, or 1 cwt. per ton of broken coke for sale. Less when broken while warm (say 1 bushels per ton). Oils flashing below 73 F. are not allowed to be stored in warehouses or shops in England. CARBONIZING. 233 RETORT HOUSE MANUFACTURE, The gas produced in part of the retort nearest the front is not usually so good in quality or quantity as that from other parts. Uneven charging reduces the temperature of the retorts and makes a poorer coke. Uneven charges cause the evolution of gases of little or no illu- minating power from the thin portion, while the thicker portion is not properly burnt off in the allotted time, and gas is lost. Retorts which allow but little room above the coals are to be preferred, as then the gas passes quickly away from contact with the heated surface of the retort, which causes the decomposition of some of the olefiant gas. The production of the hydrocarbon compounds from the coal takes place at a comparatively low temperature ; these hydrocarbon com- pounds are then broken up into simpler forms by the passage through the retort and exposure to its heated sides. Deep charges cause caking of the outer portion before the inner is worked off, the outer portion having been quickly gassified. The coke then is giving off sulphur. The thick charge cools the retort, and the gas then made is less and the tar high. (GL Anderson.) Charge should fill the retort as full as will allow convenient charging and drawing. Deep charges of coal cause caking on the exterior for some hours before the interior of the charge is worked off. The whole of the outer surface is giving off sulphur for some hours after it has given off its gas. The large mass cools the retorts for some time, while tarry vapours are being formed instead of gas. Large retorts at low heats conduce to deposition of soot and napthalene. The sulphur given off from damp coals is greater than from dry. At high temperatures the gas produced contains methane (CH^.) and free H ; and more free C in the tar and in the compounds of carbon belonging to the aromatic series derived from benzene (C 6 H 6 ) and H is separated, and napthalene, anthracene, phenanthrene, chrysene, &c. are formed. (Dr. Lunge.) At low temperatures the hydrocarbons formed belong to the paraffin series (methane), having the general formula CnH 2 n + 2, along with olefines (C^H 2 %). (Dr. Lunge.) With low heats the yield of ammonia is generally lower, which is also the case with high makes. Low temperatures, with 9,000 c*ubic feet of gas per ton, will yield, with a certain coal, 16 gallons tar, but the same coal at high tempera- tures will yield 9 gallons tar and 11,000 cubic feet of gas. (Davis.) If coal were distilled at low temperatures and the gases afterwards subjected to greater heat in separate retorts, where the heat could be accurately controlled, better results might accrue. (Foulis.) Mr. Hunt, testing in a small iron retort, found that the greatest number of candles per ton was obtained with a temperature of 234 GAS ENGINEER'S POCKET-BOOK. 1,600 F., and he considers the best heat for ordinary working is the lowest that will thoroughly carbonize in the allotted time, the stopped pipes with high heats causing loss beyond the gain by the higher temperatures. There is a certain temperature at which each coal may be made to yield the best results, both as to quantity and quality. When gas is being evolved from coal the temperature of the retort is not even along the length of the retort. When a substance is subjected to a high heat and to an advanced state of decomposition the products produced are generally of a simple nature. The higher the heats the greater the proportion of hydrogen and methane and the lower that of C. Temperature in retorts = 1,800 to 2.000 F. = temperature in hydraulic main of only 140 to 180 F. = 110 to 150 F. at outlet of latter. (J. Hornby.) Temperature in retorts rarely more than 2,2CD F. Cherry red is the best heat for iron retorts. A good orange is about right for clay retorts. If the heat of retorts is 1.000 C. (1,832 F.) before the charge is in the heat of the coals near the walls will be about 800 C. (1472 F.) and in the centre of the coals 400 C. (752 F.). The upper layer of evolved gas will be at a temperature of 1,000 C., and the lower, near the coal, 600 C. (1,112 F.) (Prof. Lewes.) If a long piece of gas piping, closed at one end, is passed through a hole in the retort lid with the open end to the air it can be used to obtain the heat of the retort at different points. (L. T. Wright.) The velocity of gas in its passage through highly heated retorts is about 5 feet per second during the maximum evolution of the gas. Damp coals cause steam in the retort, which is afterwards condensed in the condensers, and which has a tendency to lower the tempera- ture of the retort. Loss between working in summer and winter equals 9*6 per cent, in favour of the former, in the sperm value obtained from similar coals. Very high yields of gas are only obtainable with excessive use of fuel. Clay retorts usually worked at 1,082 C. At a yield of 118 cubic feet per square foot of retort, cast iron could be melted (= + 2,100 F.) in the top flue, and silver in the bottom flue ( = + 1,749 F.). The greater proportion of the CS 2 is formed after the useful gases have been driven off from the coal, and is increased if the coal be wet when put in the retort. Best temperature for Newcastle coal is dull orange or 2,010 F. Clay retorts are bad absorbers of heat compared with iron retorts. Water vapour in the retort seems to have some protective action on napthalene. (L. T. Wright.) The maximum production per square foot of retort surface may be taken as 126 cubic feet per ton, or 14-7 tons of coal carbonized per 1,000 square feet per 24 hours. There are certain paraffin hydrocarbons in the coal which are split up into simpler members of the same series and into olefinea TEMPERATURE OP DISTILLATION. 235 Fractional distillation is a means of separating liquids with boiling points at least 30 F. apart. Cannel coal carbonizes in about five-sixths the time of caking coal, and the greatest quantity of gas is evolved during the first hour of charge. Temperature of gas as it leaves the coal about 170 F. The more rapidly the coal is carbonized the better are the results. (W. Foulis.) Products. Percentage of Coal. Calories per ton of the Coal. Percentage of Heat of Combustion of Coal. Coke . . . 65-66 4,682,683 62-09 Gas (Dry) . Tar ... 17-09 7-81 1,929,252 671,231 25-58 8-90 Loss . . . 258,866 3-43 1 7,542,032 100-00 Loss occurs through the endothermic process of carbonization, as the coal appears to liberate heat and not absorb it. (Euchene and Mahler's results.) Residuals and Impurities at Outlets of Retorts in Percentage by Weight of Crude Gas. (Prof. Wanklyn.) Tar 33 per cent Watery vapour 50 Ammonia 2 C0 2 5 H 2 S 2 to 5 S. as sulphuret of carbon and organo-sulphur compounds . '15 to '3 Result of Heating to about 1000 C. (Prof. Lewes.) Ethane becomes ethylene and hydrogen. Ethylene methane and acetylene. Acetylene benzene, styrolene, retene, &G. Variation in Quantity of C0 2 and H 2 S according to the Heat of Distillation. (Lewis T. Wright.) CAKING COALS. Yield of Gas per Ton. Grs. of CO, per Cubic Foot. Grs. of H a S per Cubic Foot. 7,856 8,547 11,128 16-92 18-38 19-37 3-16 4-69 5-87 CANNEL COAL. 7,853 10,047 32-60 39-27 4-80 4-97 The "salts" usually found mixed with tar in the hydraulic and foul mains are probably sal-ammoniac, and are formed by high heats. Crude gas contains about 1 per cent, ammonia, weighing from 5J Ibs. to 8 Ibs., and about 5 per cent. C0 2 and H 2 S. 236 GAS ENGINEER'S POCKET-BOOK. Result of Carbonization at Different Temperatures. (L. T. Wright.) Temperature. Gas. Cubic Feet perTon Illu- minat- ing power Candles per Ton. H. Cit. Me- thene per Cent. Ole- fines Cent. CO. pei- Cent. N. Cent. Dull red. Hotter . Bright orange 8,250 9,693 10,821 12,006 20-5 17-8 16-7 15-G 33,950 34,510 36,140 37,460 38-09 43-77 Test 1 os 48-02 42-72 34-50 Testlost 30-70 7-55 5-83 Test lost 4-51 8-72 12-50 Test lost 13-96 2-92 3-40 Test lost 2-81 At a low rate of distillation nearly all the gas is evolved at 1,340 F. At the highest rate of distillation 66 per cent, of gas is evolved at 1,339 F. When the yield of gas per ton is under 9,000 cubic feet the temperature of the bottom flue is not above 1,580 F., but with a temperature there of 1,680 F. the yield increased to 9.378 cubic feet per ton. (L. T. Wright). Temperature of Retort. Make of Gas. Gallons of Tar. Remarks. 600 F. 750 to 800 F. 1000 F. 1830F. 2010 F. . Feet per ton. 400 1,400 6,000 8,300 10,000 68 13 to 14 gals. 9 coke very friable. faint red heat, bright cherry red heat, orange heat. Low temperatures give little ammonia. Medium temperatures give most ammonia. Higher temperatures give rather less ammonia but more CS 2 , H 2 S, and cyanogen. Make per Ton, Cubic Feet. NH S per Ton. Percentage of Coal asNH 3 11,620 10,162 9,431 7,512 Ibs. 7-411 7-894 7-504 6-391 0-331 0-352 0-335 0-285 Temperature of Retort. Make of Gas. Illuminating power Illuminants. 2,000 F. 2,160 F. Per Ton. 9,800 11,000 Candles. 16-54 12-00 Lbs. Sperm. 525 452 (L. T. Wright.) HOURLY MAKE OF GAS. 237 Coal carbonized at 2,000 yielding 9,800 cubic feet of lfr-54 candle gas equal to 555 Ibs. illuminating matter, but if carbonized at 2,160 will yield 11,000 cubic feet gas of 12 candle-power equal to 452 Ibs. illuminating matter. If caking coal be carbonized at 600 F. (hardly red in a dark place) only 400 cubic feet of gas per ton are evolved, and most of the hydrocarbons are resolved into tar. At low heats 600 F. tar and oils are formed but little gas, while at higher heats gas is formed with less tar. At a low red heat in daylight about 6,500 feet are produced per ton. At 750 to 800 F. about 1,400 cubic feet gas and 68 gallons tar or crude oil are given off ; at 1,000 (a faint red in subdued day- light) about 6,000 cubic feet gas ; and at 1,830 (a bright cherry red) about 8,300 cubic feet with 13 or 14 gallons tar are evolved ; and at 2.010 (orange) about 10,000 cubic feet per ton with 9 gallons tar. (Gesner.) Composition of Gas from Newcastle Coal Carbonized at Different Heats. (Thorpe.) Gas per ton of coal, cubic feet . . 8,250 9,692 12,006 Illuminating power, candles . . . 20-59 17*80 15*60 Unsaturated Hydrocarbons, per cent. 7'55 5-83 4-51 Marsh Gas 42-72 34-50 30-70 Carbon Monoxide .... 8'72 13'50 13'96 H 38-09 43-77 48'02 N. 2-92 2-40 2-81 Percentage and Specific Gravity of Gas .during each of Five Hours' Charge. First hour 46-6 per cent, gas given off '677 average specific gravity. Second hour 27-4 -419 Third hour 16-0 '400 Fourth hour 7'3 -322 Fifth hour 2'7 Another experiment gives First hour 51 -3 per cent, gas given off specific gravity not taken. Second hour 33-5 Third hour 11-8 ' Fourth hour 3-4 1 ton coal distilled a about 1,650 F. will be carbonized in 6 hours. V 2,010 F. The greatest quantity of gas from caking coal is evolved during the second hour. 238 GAS ENGINEER'S POCKET-BOOK. Wigan Caunel (1 ton) produced First hour 3,320 cubic feet. Second hour .... 2,940 Third hour 2,660 Fourth hour .... 1,040 (Herring.) Six-hour Charges. At end of first hour one-sixth of the total quantity of gas is given off, at commencement of second hour the coal becomes soft, and during the second, third, and fourth hours yields gas from innumerable small jets, at the fifth hour it is compact and doughy, the gas issuing from throughout the mass. At the commencement of the sixth hour it is still black as at first, and the evolution of gas, which has been fairly uniform, commences to decrease very rapidly. At 5 hours gas almost ceases to issue, and coke becomes incandescent and brittle. Quality of gas nearly uni form for first five hours, but deteriorates greatly the last hour, often being not more than 3 candles. Four-liour Charges. Periods of three-quarters of an hour correspond to those of one hour in above remarks. The work done in the retort during the last hour of the charge, amounting to about 5 per cent, of the whole, is also getting the retort in a condition of heat to receive the next charge. It has been proposed by the " Journal of Gas Lighting " to connect the mouth- piece of the retort by means of, say, a 2-inch or 3-inch tube, provided with a cock, with the interior of the setting, and divert the gas yielded during the last hour of the 6-hour charge, so that it may assist in heating the retorts, and not deteriorate the quality of the gas already made. First hour | volume of 10 candles ; second hour and half, volume of 17 to 18 candles ; third hour, i volume of 14 candles ; remainder, 8 to 10 candles at high heats, making 11,000 feet gas of 14 candles. (Butterfield.) _, Gas made Hours - percent. 1 16*6 Gas strongly impregnated with tar. 2 . ... Coal becomes soft. 3 . . . . In a state of intumescence and yielding. 4 . . . .Gas from innumerable small jets. 6 . . . . A compact and doughy mass. 6 . . . . Coal still black, yield of gas decreasing rapidly, sulphur compounds being evolved, quality about 3 candles. CLIMATIC EFFECTS ON DISTILLATION. 239 From tests of a Scotch coal, giving an average of 11,250 cubic feet per ton of 30'18 candle power, Mr. W. Wallace, F.I.C., found a variation both in illuminating power and pounds of sperm per ton, according to the temperature : Lbs. Sperm per Ton. Illuminating Power. In January . 1,136 29-44 February . . . 1,140 29-56 March 1,122 29-08 April . ... ,135 29.41 May . ,218 31-58 June . . . . ,208 31-32 July .... ,209 31-34 August . . . ,209 31-34 September . ,178 30-54 October .... ,146 29-72 November . ,139 29-53 December . . . ,124 29-14 Average . 1,164 30-18 Or by temperatures Degrees Fahr. Lbs. Sperm per Ton. Illuminating Power. 36 to 40 ,108 28-73 41 to 45 . . . . ,124 29-14 46 to 50 ,142 29-61 51 to 55 .182 30-65 56 to 60 ,206 31-27 61 to 69 . . ,215 31-50 Average . 1,163 30-15 Proportions of coal, coke, and tar used per ton in firing retorts : 2| cwts. of coke are used per ton of coal carbonized with gaseous regenerative firing. 3 to 4 cwts. of coke are used per ton of coal carbonized with ordinary furnaces. 1 ton of tar is equal to about 2 tons of coke in firing. Loss in direct fired settings through heat dissipated up chimneys. Of N and C0 2 or and CO = 5943'4 B.T.U. out of 14550 B.T.U. from 1 Ib. C, or 41 per cent. Any increase of air above the theoretical quantity required increases the loss up the chimney. 50 per cent, is usually the quantity lost as then the excess air is only 20 per cent. Too little air in direct fired settings reduces the heat per 1 Ib. fuel in increased proportions. 240 GAS ENGINEER'S POCKET-BOOK, Pounds fuel used per 100 Ibs. coal carbonized : Coke Breeze 17-36 Ibs. 2-74 Ibs. The above are calculated from the quantity used in a week of 6 days. March 21st, 1892. Composition of Gases in Generator Furnaces. EBELMAN'S GASOGENE. SIEMEN'S GENERATOR. Air. Air and Steam. CO . 33-3 27-2 26-0 C0 2 0-5 5-5 4.5 N 63-4 53-3 67-5 0-5 a 2-8 14-0 100-0 100-0 100-0 First analysis most like the exact chemical proportions for the entire conversion of carbon into CO without C0 2 which are 34J per cent. CO and 65 per cent. N. Amount of Primary and Secondary Air should be tried and fixed in each case when using regenerator furnaces. Best materials only should be used in such settings. Areas of openings for introduction of primary and secondary air and gas ducts vary considerably, and should all be made so that they can be altered as required by a sliding brick or tile. Only a comparatively low temperature is required to convert fuel to CO, and thus the admission of cold air under the furnace bars enables the furnace to last long, owing to less wear and tear, and prevents the formation of clinker, ash only being found between the bars. In regenerator furnaces the gases, before combustion, should be of uniform quality and temperature, and should then be directed into and distributed over all the interior of the setting. The arrangement should be such that combustion shall not be complete until just before the burnt gases are leaving the setting and are about to enter the flues of the regenerator. The limit of heat which may be employed in a setting is the fusible point of the brickwork in the hottest part, and the producing power of the setting is governed by the temperature of its coldest part. It is impossible to introduce air into a gas-fired retort setting and properly distribute it for combustion, without it becomes heated to the necessary temperature for combustion with the primary gases. It is only by analysis of the gases that it can be accurately ascer- tained if the primary and secondary air are being used in their proper proportions. With ordinary settings M. Euchene calcnlates that 12-8 per cent, of heat evolved from the coke, ets., is lost by radiation through walls, etc. REGENERATIVE SETTINGS. 241 Secondary air should be heated to about 1.800 F. One third the heat generated by the combustion of fuel is made when CO has been formed, the balance being generated when this is converted into C02 Saving in fuel with generator settings = about 25 per cent. ,, ,, regenerator = 50 Theoretically 1,100 F. are required in the producer. Practically 1,800 F. Composition of producer gases by volume. Ideal. Actual. CO .... 34-7 per cent. 25-7 per cent. CH 4 2-75 H 65-3 per cent. 14-06 N 52-74 C0 2 4-75 Temperature at combustion chamber . 2,600 F. ., crown of setting . . 2,400 F. entrance to regenerators 2,150 F. ,. outlet of last waste gas flue 1,000 F. The smaller the percentage of ash in the coke used for regenerative firing the better, but, if porous, 10 per cent, of ash can give good results. A vacuum of three-fifths is sufficient at outlet of last waste gas flue. Analysis of gas at last waste gas flue : CO . . .0-710 . . .0 C0 2 . . . 16-6 |N. . . . 83-3 Of each 1 Ib. coke placed in regenerator furnaces, 18 per cent, is ash, 78f carbon, 3* H. Of the carbon 90 per cent, is converted to CO and requires for complete combustion about -45 Ibs. O. For the hydrogen about -26 Ibs. is required, or a total of -71 Ibs. O equal to 3 - l Ibs. of ordinary air to be raised, say 1,800 F. Specific heat of air = 0-2374, therefore 3-1 Ibs. x 0'2374 x 1800 = 1324-7 units of heat. There is always a considerable loss of heat through the N. passing away hot into the air. No gain of energy with gaseous fuel, but rather a loss. The advantages being that the absolute conversion into CO 2 can be made to take place at any or several desired points, which might be impossible to reach by means of direct firing, and, again, the loss of heat which is radiated from the furnace in a direct fired oven is not so great, as the intensest heat is only obtained at the point where the heat is required. O.E. E 242 Heat in recuperators should not be more than a dull red below the secondary air inlet, as this will probably mean too little secondary air being used. No blue flame should be visible at outlet of flue, as this shows unconsumed CO. About one-third the total heat evolved by the fuel is used in transforming the solid into gaseous fuel. Producer gas in Siemen's furnace with coal containing 70 per cent, fixed carbon, 16 per cent, of coal gas, 14 per cent, ash oxygen and nitrogen (coal equals about 7,200 calories). Producer gas consists by weight of 16 parts coal gas, 163*3 of CO, and 222 of N. Coal gas = 10,000 calories, CO =2,400 calories, then the total calories = 551,920 against 700,000 for the coal proper. (Sir J. Lowthian Bell.) 2 to 3 per cent. C0 2 in generator gases shows very good working. 5 to 6 fair 10 ., defective (W. Thorner.) Wide furnaces prevent the fire burning too low. There should be no exhaust on furnace except when drawing up the heats. Less air is required with a light than a heavy coke. Ordinary furnaces allow a large proportion of the CO to escape without being oxidized to C0 2 . About 25 per cent, of the heat evolved in an ordinary furnace passes up the chimney, of which only one-fourth is required for the necessary draught. Breeze consists of much earthy matter, and but little carbon, which makes it a weak fuel, and much scoriae is deposited when burning it. Briquettes are made on the Continent to burn coke dust and tar or pitch for heating the furnaces. Tar and coke dust are sometimes mixed on the retort house floor and then used as fuel. Briquettes are also made by hydraulic pressure, the proportions being 10 per cent. pi j ch to the quantity of breeze. Clegg stated that when tar was less than 3d. per gallon it paid to burn it in the furnaces, at present it only pays to burn when less than f d. Advantage of tar firing is the slow and even rate of supply as compared with coke firing, by which the necessary air supply is much lessened, and the consequent cooling effect of the inert gases is not so great. The superiority of liquid fuel over solid is principally due to the H contained in it, H evolving five times the heat, weight for weight that carbon does on combustion. The use of steam does not appear to have any beneficial effect when employed to inject tar into retort furnaces ; it has been shown by Mr. Dexter that no increased heat can possibly result by its use, but that rather does it tend to lower the heats. Twenty gallons tar required to carbonize 1 ton coal equals about 6 gallons tar per 3 bushels coke. REGENERATIVE SETTINGS. 243 Provide a good quantity of water in the ash pans as the steam prevents the formation of clinker, and prevents the over-heating of the fire-bars. It is a moot point if the water gas made from the evaporation in the ash pans is an advantage or not, the amount of heat absorbed in converting water to and H being very great, but being taken from the lower layers of the furnace it does not materially affect the heat of the bulk of the fuel, while the gain from the burning of the hydrogen is considerable. A jet of steam is of assistance under the bars of generator settings. The steam from the ash pans is converted into CO and H in passing through the red-hot fuel in the furnace. Quantity of water evaporated per furnace per hour equals about 3 gallons. Steam required for producer equals about 32 Ibs. per 100 Ibs. C consumed or 3-70 Ibs. water per 100 Ibs. coal carbonized. Clinkering is reduced about one-third in regenerator settings. Clinkering should be done often enough to prevent such an accumulation as will stop the air- way between the fire-bars. Clinker is due to the combination, under the influence of heat, of the inorganic, or incombustible matter of the coke (the ash of the coal). This consists principally of silica, alumina, lime, iron, &c., which fuses together to form a kind of slag. (Hornby.) Furnaces require repair about every six months. Average life of clay retort 900 working days. Clay retorts will carbonize about 4,000,000 cubic feet. Iron retorts about 650,000 cubic feet of gas, and they are done. The broken surface of a brick is much sooner acted on by heat than is the smooth face which has a protecting skin upon it. Lumps are therefore to be preferred where possible. The saving due to the producer may be taken at 52-26 per cent. regenerator 47-74 100-00 If a blue flame is seen at outlet of chimney of regenerative retort settings CO is being passed away, and more secondary air should be let in. Generator gas should consist of 34'7 per cent. CO and 65-3 per cent. N. Chimney gases should contain 21 per cent. C0 2 , 1 per cent. O and 78 per cent. N. Air rapidly absorbs heat, and when passed over heated surfaces it becomes raised in temperature approximating closely to that of its surroundings. The waste gases in a regenerator setting have been known to be reduced in temperature from 1,200 F. to 500 to 600 F. by the incoming of the secondary air, all of which heat is being saved and used again in the furnaces. B2 244 GAS ENGINEER'S POCKET-BOOK. 1 lb. C converted to C0 2 yields 14,544 heat units. About double the necessary air required in a direct fired fur- nace. By the higher heats of regenerative furnaces Mr. Foulis increased the producing power of the works 60 per cent. One-half per cent, of free in the waste gases may be considered good working. The depth of fuel should be kept as regular as possible. The use of tar as fuel causes difficulty in controlling furnaces, and regular and complete combustion. The loss of gas from clay retorts in good working order is not at all important. (L. T. Wright.) However hot the retort, an immediate and heavy fall in temperature must follow the introduction of the charge, to be worked up again to its maximum in the allotted period. (A. F. Browne.) 4 per cent, air reduces the illuminating power 25 per cent. 1 per cent, of common air diminishes the illuminating power 6 per cent. 45 per cent, of air renders the gas non-illuminative. 1-inch back-pressure in retorts equals l-24th candle power lost. The sulphur compounds are decomposed at a temperature of about 400 F. In gas from wet coals the olefiant gas is reduced one-third. Crude gas contains 4 per cent, by volume of gaseous impurities (H 2 S and C0 2 gas). About 1 per cent, by volume of the crude gas is ammoniacal About 3 per cent, by volume of the crude gas is C0 2 . About 1J per cent, by volume of the crude gas is H 2 S. Luting generally made of 2 parts clay to 1 part spent lime. If the coke were drawn immediately it became incandescent, say about half-an-hour before the charge was done, much of the trouble with the sulphur compounds would be avoided, High; heats give a.harder coke generally. Gas coke contains C, N, S, H, and 0. Coke contains about 88 per cent, carbon. Coke when drawn from the retort and slaked contains about 25 per cent, moisture. Coke averages 1,360 Ibs. per ton of coal, with about 4 per cent, ash in the coke. About 34 gallons water required to quench 1 ton coke, of which not more than 671bs. water remains permanently in the coke. If steam be introduced along with the air into a coke-making plant, a larger percentage of ammonia can be extracted. 59 Ibs. slack coal required in furnaces to carbonize 2 cwt. coal. 41 Ibs. lump coal required in furnaces to carbonize 2 cwt. coal, say 570 Ibs. coal per ton. In the petroleum-heated locomotives on the Great Eastern Railway, a thiti coal fire 6 inches thick (an ordinary one being 18 to 24 inches), mixed with lumps of chalk to keep the bars covered, is used so as to keep sufficient heat up, when stopping, to re-light the oil when re-starting. NH 8 in ascension pipes, say 560 grains per 100 cubic feet, LABOUR REQUIRED TO CARBONIZE. 245 Men Employed in Making say 3,000,000 Cubic Feet per Diem (Hand Charging). s. d. Retort house work only, 17 (first-class) men, made up of firemen and scoop drivers .... at 1 Foreman 20 (second-class) Men (stokers) 10 (third-class) Men (fire-rakers) . ... 7 Coal trimmers 1 Pipe cleaner 1 Scurfer 1 Flue cleaner ....... 1 Lobby boy 1 Fitter . . . . The above represents the number of men employed on each shift of eight hours. (January 13th, 1893.) Total Number of Men Required to Charge 240 Retorts with 240 Tons of Coal per Diem at Glasgow, Working 8-hour Shifts. (A. Wilson.) Manual Labour. Machine Work. 60 Stokers 6 Charging machine men 15 Firemen 6 Drawing machine men 15 Ashmen 15 Firemen 30 Coalbreakers 15 Ashmen 10 Bogie drivers 10 Coke men 10 Coke men 6 Pipe cleaners 3 Waterboys 1 Lid cleaner 3 Foremen 6 Lid men 146 men. 3 Coal breaker men 3 Locomotive boys Also 7 horses to draw out the coke. 3 Shunters 3 Foremen 77 men. Number of Men Employed on Furnaces (during 8 hours). li firemen clean 2 fires and fill 4. 4 firemen in 24 hours attend 4 fires (cleaned every 6 hours). 1 fireman attends the equivalent of 6 '01 fires (on the ordinary open double grate system). Number of men employed on furnaces (during 8 hours) of 15 sets. " Buffalo Bill " settings (1 furnace to five sets). "2\ firemen clean 4 fires and feed from the top every 2 hours. 1\ firemen in 24 hours attend 3 fires (fires cleaned every 6 hours). 246 GAS ENGINEER'S POCKET-BOOK. 1 fireman attends the equivalent of 12 fires (on the ordinary open double-grate system). Each stoker may be made to handle an average of 4 ton coal per day. Charging should be performed in rather less that one minute. The air compressor at the South Metropolitan Gasworks used with the "West stoking machinery, shows a high duty, the mechanical efficiency is 80*3 per cent., the compression efficiency is 82*1 per cent., and the air delivery equals 369*3 cubic feet per I.H.P. per hour. To Prevent Stopped Pipes they should be kept cool, and light seals in the hydraulic maintained in liquor and not tar. Space between ascension pipes and front wall of bench should not be less than 8 inches. Water may be introduced at the top of the ascension pipe and allowed to trickle down the sides of the pipe. Stopped pipes sometimes attributed to oscillation and pressure in the retorts from the dip and the exhauster. Thick tar and soot and stopped ascension pipes are sometimes caused by porous parts in retorts, either new or recently cleared from carbon, which allow the gas to pass through and burn in the setting, while the soot and tar are carried up and deposited in the ascension pipe and hydraulic. The obvious cure is to paint the inside of the retort after such clearing of carbon and when new, with thin fire- clay mortar, and thus close the pores. Suggestions for the Curing of Stopped Ascension Pipes. Allow water to trickle down the interior from the top. Place a bowl of water, or rag, or waste soaked in oil, small coal soaked in water, or pieces of solid grease, inside the retort, just below the bottom of the ascension pipe. Keep open all doors, windows, or other available apertures. Bring a supply of cold air, from outside, to the front of the bench by means of pipes. Keep the retorts charged to their utmost capacity. Lower the heats of the retorts ; this also clears the hydraulic by causing oily tar to pass off from the coal. Loss from stopped pipes has been known to exceed 10 per cent, of the gas to be obtained from the coal. Stopped ascension pipes usually caused through excessive heat from setting. To diminish the trouble, walls in front of benches should be 14 inches and not 9 inches thick. Rapid radiation of heat and smooth interior surface, said to obviate stopped pipes. To prevent stopped ascension pipes, leave the retort mouthpiece and the pipe open to the air. The temperature of the pipes must be moderated by a supply of water which is led into them by a U-shaped tube screwed into their upper ends. The water drips into this tube from a supply above it. 03 to 70 ounces water per retort per hour required. EFFECTS OF HEAT. 247 The gas in the ascension pipes is usually of a temperature of about 200 F. Air circulating round the pipes and mouthpieces. Water supplied internally or externally. Liquor supplied internally or externally. A lump of coal in the mouthpiece. A handful of oily waste in the mouthpiece. Animal fat in the mouthpiece. Increase in length of rising pipe. Plate or plates inside mouthpieces to prevent radiation of heat from inside retort. Lining mouthpiece with fire-clay. Air or water jacket to ascension pipe. Carbon deposited in the retorts is generally increased by increase of pressure. An oscillation caused by a badly working exhauster causes a greater deposit of carbon than a steady exhaust. Pressure and oscillation are the chief causes of deposition of carbon. The pressure on retorts is sometimes as high as 15 inches water where an exhauster is not in use and the carbon deposit is then considerable. The carbon deposited in the retorts consists of the richest illu- minants of the gas which have been solidified instead of carried forward in the gas. If there be a heavy pressure in retorts some of the hydrocarbons are deposited as carbon in the retorts. Under pressure some of the most valuable hydrocarbons are deposited in the retort as carbon or scurf. The removal of the carbon from sloping retorts is easy, as the position of the latter causes a current of cool air to pass up when both doors are opened. Carbon or scurf is removed by a chisel bar, or by allowing the oxygen of the air to burn the deposit until it is thin enough to remove easily ; this should be done about once a month. The carbon in a retort being highly non-conducting, causes con- siderable waste of fuel, and should therefore never be allowed to get very thick. Clay retorts are practically gas-tight up to about J-inch pressure. To prevent carbon deposits, reduce the dip and the back pressure as much as possible. Table of the Effects of Heat. Soft iron melts Cast iron melts . Gold melts Copper melts Silver Bronze ., (copper parts, tin 1 part) 16 Degrees. Fahr. . 3,945 . 2,786 , 2,016 . 1,996 1,873 1,750 Degrees Fahr. Brass melts (copper 3 parts, zinc 1 part) . . . 1,690 Brass melts (copper 2 parts, zinc 2 parts) . . . 1,672 Diamond burns . . 1,552 Bronze melts (copper 7 parts, tin 1 part) . . 1,534 248 GAS ENGINEER'S POCKET-BOOK. Table of the Effects of Heat continued. Degrees. Degrees. Fahr. Fahr. Bronze melts (copper 3 Steel becomes a full yellow 470 parts, tin 1 part) . 1,446 Steel becomes a pale straw Enamel colours burn . . 1,392 colour . . . . 450 Iron red hot in daylight . 1,272 Tin melts . 442 Iron red hot in twilight . 884 Steel becomes a very faint Iron red hot in dark 800 yellow . . . . 430 Charcoal burns . . . 802 Tin 3 + lead 2 + bismuth Heat of a common fire 790 1 melts 334 Zinc melts . . . . 773 Tin and bismuth, equal Mercury boils . 660 parts, melts . . . 283 Linseed oil boils . . . 640 Sulphur melts . 218 Lowest ignition of iron in Bismuth 5 + tin 3 + lead the dark 635 2 melts . . 212 Lead melts . ... 612 Water boils 212 Steel becomes dark blue, Wax melts . . . . 149 verging on black . 600 Tallow melts . 92 Steel becomes a full blue . 560 Acetic acid congeals . . 50 Sulphur burns . 560 Olive oil congeals . 36 Steel becomes blue . . 550 Water freezes . . . 32 Steel becomes purple 530 Milk freezes 30 Steel becomes brown, with Vinegar freezes . . . 28 purple spots . . . Steel becomes brown 510 490 Sea water freezes Strong wine freezes . . 28 20 Bismuth melts . . . 476 Turpentine freezes . 14 Colours of Different Temperatures. (Becquerel.) I )egrees. Degrees. Fahr. Fahr. Faint red 960 White heat. . . . 2,370 Dull red .... 1,290 Bright white heat . 2,550 Brilliant red . . . 1,470 Brilliant white heat . . 2,730 Cherry red . . . . 1,650 Melting point of cast iron 2,786 Bright cherry red 1,830 Welding heat . . . 2,800 Orange . . . . 2,010 Greatest heat of iron blast Bright orange . 2,190 furnaces 3,300 600 F. Faint red in dark room. 662 F. Mercury boils. 810 F. Antimony melts. 1,869 F. Brass melts. 1,873 F. Silver melts. 1,996 F. Copper melts. 2,786 F. Cast Iron melts. Temperature of iron when red glow has disappeared, 404 C. It is said that no reliability can be placed on Wedgewood's pyro- meter. PYROMETERS. 249 Pyrometers. One part of zinc and 4 parts of copper melts at 1,050 C. ; 1 part of zinc and 6 parts of copper melts at 1,130 C. ; 1 part of zinc and 8 parts of copper, at 1,160 C. ; 1 part of zinc and 12 parts of copper, at 1,230 C. ; and 1 part of zinc and 20 parts of copper, at 1,300 C. The difficulty of getting pure metals to make these alloys, and of keeping them at the initial proportion, is against their use. The expansion of metals, clays, liquids and gases under heat is also used with varying success. The Lamy pyrometer, based on the decomposition of carbonate of lime under heat, is one of the best ; but it will only register between 700 and 900 C. Herr C. Schneider proposes the use of nitrifiable test cones, con- taining silica 65 per cent., alumina 8'3 per cent., ferric oxide 8'7 per cent., lime 10*6 per cent., and potash 7'6 per cent., or in vary- ing proportions, to test the heat of chambers with heats from 1,150 C. to 1,700 C. The greater the quantity of silica the more refractory the cone, the above mixture melting at 1,150 C. ; and by the substitution of 8 per cent, of boracic acid for the equivalent of silica the melting point equals 960 C. Or crystallized borax 193 parts, marble 50 parts, china clay 52 parts, sand 96 parts, will melt at 960 C. Seger's standard fusible cones are used to determine the tempera- tures at which fusion occurs. These cones are tetrahedra, compounded of mixtures of clay and sand with certain fluxes. For temperatures from 1,300 to 1,700 F., soda and lead oxide form the flux ; while boric acid is used for temperatures from 1,700 to 2,050 F. The same flux is used with gradually increasing proportions of alumina and silica up to 3,450 F. The last cones of the series, which are stated to fuse at temperatures from 3,500 to 3,950 F., consist of pure aluminium silicate. Mr. P. Mahler's calorimeter consists of a shell or hollow cylindrical vessel, enclosed in another containing water at a known temperature. The shell being hermetically closed, pure oxygen, at a pressure of several atmospheres, is admitted, and the fuel fired by an electric spark, when the pressure of the compressed oxygen causes complete and almost instantaneous combustion. The heat generated is trans- mitted to the water surrounding the shell, the temperature of which rises immediately. Mr. Mahler uses only one grain of combustible. When gas is tested a vacuum must be produced in the shell before gas is admitted, and the quantity of oxygen necessary for com- bustion previously determined. Illuminating gas ignites with oxygen at a pressure of five atmospheres, producer gas requires a pressure of about half an atmosphere in the oxygen. To find temperature of a furnace weigh a piece of metal, place in furnace, withdraw when heated and immerse in a known weight of water Then T l - w *<%- + T t where Tj = temp, of metal before immersion w = weight of water T-2 = ,j water S = specific heat of pyrometer Ta= after s = water (=1) W = weight of metal. 250 GAS ENGINEER'S POCKET-BOOK. Tallow . Spermaceti Wax, white Sulphur Tin Bismuth . Lead . Zinc . Temperature of Fusion. Degrees. Degrees. Fahr. Fahr. . 92 Antimony . 810 . 120 Brass . . . 1,650 . 154 Silver, pure. 1,830 . 239 Gold, coin . . 2,156 . 455 Iron,cast,medium 2,010 . 518 Steel . . . 2,550 . 630 Wrought iron 2,910 . 793 Melting Points of Fusible Alloys. Tin. Lead. Bis- inuth. Degrees. Fahr. Tin. Lead. Bis- muth. Degrees. Fahr. 2 3 5 199 8 15 430 1 1 4 201 1 2 440 3 2 5 212 8 17 450 4 1 5 246 4 10 470 1 1 1 255 1 3 480 2 2 1 292 4 14 490 3 3 1 310 8 33 500 4 4 1 320 1 5 510 H 1 330 4 25 520 2' 1 340 4 30 530 4 1 365 1 10 540 1 1 370 1 12 550 6 1 380 1 25 560 4 7 420 An average sample of coal gives the following figures : Carbon (C) 82*12 per cent. Hydrogen (H) 5-31 Nitrogen (N) 1-35 Sulphur (S) 1-24 Oxygen (0) 5'69 ,, Ash . 4-29 ,. (Lancet.) Percentage of coal in its use : 10,000 cubic feet gas = 17 per cent. 10 gallons tar = 5'1 ., Condensed liquor = 7 - 9 Coke = 70 (Professor Lewes, 1894.) RESIDUALS FROM COAL. 251 Approximate composition of bituminous coal : C 80-0 per cent. N 1-5 per cent. H 5-0 5-0 S 1-5 Ash 3-0 Moisture 4-0 per cent. Calorific value 8,020 thermal units. (Professor Lewes.) Cannel coal -specific gravity 1-1 to 1-4, organic matter consists of C = 70 to 85 per cent. ; = 5 to 15 per cent. ; H = 5*5 to lO'O per cent. ; N = 1 to 2 '5 per cent. ; S = 0'5 to 2 '5 per cent. ; Ash 5 to 20 per cent. Ash from average Newcastle coals .- Silica 60 Peroxide of iron 16 Alumina 12 Lime 10 Potash 1 Magnesia 1 2 to 4 gallons of water per ton is the average moisture in mechanic.il combination. Laboratory tests of coals are generally 15 to 20 per cent, higher than actual working results. About 16 gallons of water are produced by carbonizing 1 ton coals. Gas made per ton Gas Light & Coke Co \ year to December, 1892, 10,949 cubic feet. Coke made '617 ton per ton. Breeze '064 C0 2 in crude gas . . . . 2' 5 to 3 per cent. H 2 S 1 to 2 CS 3 is formed by the action of sulphur vapour upon red hot carbon. Tar can be carbonized in ordinary clay retorts if allowed to -run into the ascension pipe on to a fire clay tile fitted in the mouthpiece to prevent any accumulation of tar behind the lids, 40 gallons being burnt off in 6 hours. Iron retorts are however better. Tar conduit pipes should be large, say 2-inch. Paper becomes charred at 400 P. Table showing conversion of the elements of coal on carbonization = CH 4 & C 2 H 4 etc. N J 35 - 26 free-in gas and | in tar, 48*68 in coke. 252 GAS ENGINEER S POCKET-BOOK. A good gas coal should contain as large a percentage of H over and above that required to combine with the as possible, and this should not be less than 4 per cent., while 5 per cent, will show a high quality coal. To obtain the quantity of H Avhich will oxidize on carbonization divide the percentage of O by 8 and deduct the dividend from the percentage of H. Total quantity of carbon in coal = 82 per cent. Gas contains = 16 Coke and tar = 66 Caking coal has specific gravity 1*25 to T35, and the organic matter in it consists of 80 to 90 per cent. C, 4-5 to 6 '0 per cent. H, 5 to 13 per cent. 0, and 1 to 2-5 per cent. N, average ash 7*5 per cent., sulphur 0'5 to 2'5 per cent. (Butterfield.) Lancashire Coal. Newcastle Coal. Welsh Coal. Scotch Coal. C per cent. 80-70 83'60 86-26 78-50 H 5-50 5-28 4-66 8-33 o 8-48 4-65 2-60 8.33 N 1-12 1-22 1-45 1-14 S 1-50 1-25 1-77 1-45 Ash 2-70 4-00 3-26 4-00 Coal contains from 50 to 80 per cent, by weight, of carbon. Average composition 80 per cent. C, 5 per cent. H, 8 per cent. 0. 4 per cent, ash, 1J per cent. S, 1 per cent. N. Coke equals 61 per cent., specific gravity equals 1-279, weight per cubic foot equals 80 Ibs. Bituminous coal contains from 6 to 10 per cent, water. In most Tars there are 40 per cent, of compounds capable of conversion into illuminating gases. An ordinary sample of tar will yield at least 16,000 cubic feet of 15 candle gas per ton of 200 gallons, with coke, free from ash, weigh- ing about 10 cwt., and if produced at proper temperatures equal to foundry coke, ammonia equal to the production of 16 Ibs. sulphate per ton of tar. The theory of the tar process as used at Widnes is that a fresh charge of coal cools the retort for a time, during which a considerable quantity of tarry vapours are being given off from the coals, and these tarry vapours are carried along the duct, as the second retort is called, and there gasified into permanent gases instead of being deposited in the condenser mains as tar. The volume of Gas from Wood Charcoal amounts to 250 litres per kilogramme, and, when prepared on a large scale, it contains C0 2 9-14 per cent., CO 18-08 per cent., H 49-11 per cent., CH 4 16-04 per cent., O 0-26 per cent, N 7-37 per cent. (Comptes Rendus.) Wood Gas gives about 8,000 cubic feet per ton of poor gas. Mr. W. King, of Liverpool, found that the average yield per ton of tar thoroughly dried at 212 F. before carbonization was 12,000 cubic GAS FKOM DIFFERENT SUBSTANCES. 253 feet 01 4-candle gas, 5 cwt. charcoal (worthless for fuel), 33 per cent. CO, and very little tar. By the Dinsmore process, following a coal gas carbonization, afcout 10,000 cubic feet per ton of 19-candle gas are obtained from a poor coal. One Ton Split Wood yields 11,000 cubic feet per ton of 16 candles, with 4 cwts. charcoal, and 1 to lcwts. of tar, with a large quantity of C0 2 (9 to 18 per cent.). Cork refuse made 18,000 cubic feet gas per ton of good quality and purity. (N. H. Humphrey.) Pine Wood Sawdust carbonized at 1,500 F. yields 12,300 to 15,700 cubic feet per ton of dried material of 15 candles (specific gravity 590 to -620), and contains about 7'5 per cent, illuminants, 33 per cent. H, 27 per cent, CH 4 , 32 per cent. CO. High heats, light charges, and plenty of red-hot surface have been found best when carbonizing wood for gas-making purposes. Peat perfectly dried and compressed yields at red heat 11,000 cubic feet per ton of 17 to 18 candle gas with 9 cwts. coke, 15 gals, tar, and a quantity of ammonia. (Butterfield.) Peat, average composition : Water 16-4, C 41 -0, H 4-3, 23 '8, N 2 '6, ash ll'S ; sp. gr. 1-05 ; gives 8,400 B. T. U.'g per 1 Ib. The tar should be removed as Boon as its temperature is down if. 100 to 110 F. Gas washed with the heavier hydrocarbons, as in a tar seal in p hydraulic main, absorbs a number of the lighter hydrocarbons which would otherwise remain in the gas and give it a higher illuminating power. If too much tar is allowed to remain in the hydraulic main, the heat of the incoming gas gradually boils off the lighter oils and causes the formation of pitch. The gas which enters the hydraulic main from the ascension pipe, carries with it a number of hydrocarbon vapours, condensing at from 140 to 160 F. Mr. L. T. Wright proposed to run in water to keep the temperature of the hydraulic main at about 100 F., and thereby reduce the quantity of impurities in the gas. The lighter hydrocarbons which condense at temperatures above 100 F., do not injure the illuminating power of the gas, and may absorb any excess of napthalene. (Herring.) If a hot liquid is used in the hydraulic mains, weak ammoniacal liquor would be likely to liberate its ammonia, and increase the amount of that impurity to be removed later on. Gas as it leaves the retorts is enveloped in very minute tarry vesicles which require friction to break thtm up. Gas on leaving the dip-pipe should pass through water and not tar. Liquor may be run in to replace tar in hydraulic twice a day. Hydraulic main tar will, at 130 F., dissolve upwards of 70 per cent, of napthalene, so that it will be seen what a powerful factor in re- moving this is eliminated by using liquor seals in the hydraulic mains. The liquor in the hydraulic main consists of sulphocyanide and hyposulphate of ammonia, also some carbonate and sulphide. 254 GAS ENGINEER'S POCKET-BOOK. Anti-dip-pipes should be worked so that there is a pressure in the retorts, and then no deleterious gases are drawn in through cracks in the retorts. Mr. Gandon found an increase of 300 to 400 feet per ton with anti- dip pipes. At outlet of hydraulic main -3 to -5 of the condensable constituents are deposited. (Professor Wanklyn.) Half to one- third the condensable vapours are deposited in the hydraulic mains. Crude gas contains about 143 grains ammonia per 100 cubic feet, 2-95 per cent. H 2 S., 2-04 per cent. C0 2 . In the hydraulic main, for every 100 volumes free ammonia there are about 24 volumes CO 2 and 11 volumes H 2 S. Temperatures found in Ascension Pipe. (W. Foulis.) 18 Inches from 12 Feet from 22 Feet from Mouthpiece. Mouthpiece. Mouthpiece. 890 to 518 F. 444 to 167 F. 246 to 144 F. Temperature in retort, 18 inches from mouthpiece, 1,110 to 1,040 F. Temperatures fell as above during charge, always getting lower as charge was worked off. Gas made equalled 10,000 cubic feet per ton. If only 6,000 cubic feet per ton were being made, temperature, at 18 inches from mouthpiece, in ascension pipe would probably be only 4 00 to 500 F. Temperature of gas leaving hydraulic main, 50 to 60 C., or 110 to 150 F. Temperature of gas leaving condenser, 15'5 C. Temperature of foul main averages about 110 F. to 138 F. Usually considered, the temperature of gas in leaving the retort squais 200 to 300 F.. but unless it is as high as 480 F. thickening t)f the tar in the hydraulic, and choking of the ascension pipe will certainly occur. The gas leaving a retort freely has only a temperature of 220 to 830 F., owing to the great absorption of heat on its assuming a gaseous form. Temperature of gas 3 feet above mouthpiece 150 to 170 F.; 17 feet from mouthpiece 120 to 135 F. M. Euchene gives (1900) chimney gases, ordinary retorts, 1,787 F. Temperature in gas in retort, at first 1,166 F., at end of charge 1,355 F., average 1,260 F., but as the volatile products come off early, average taken as 1,202 F. Temperature in retort mouthpiece from 788 F. to 824 F. Temperature in hydraulic main 176 F. Temperature in charge in retort 932 F. in first half -hour, rising to 1,740 F. during distillation. CONDENSING GAS. 255 CONDENSING. The Products of one Ton of Newcastle Coal after Carbonization are: Lbs. Per Cent. 10,000 cubic feet of gas . . 380 . . 17-0 10 gallons of tar . . . . 115 ... 5-1 Virgin gas liquor . . . . 177 . .7-9 Coke 1,568 . . . 70-0 2,240 100-0 One ton of coal yields 5 per cent, weight of tar (approximately). (Wanklyn.) About 8 feet of H 2 S is contained per 1.000 cubic feet of Newcastle coal gas. About 25 cubic feet of CO 2 is contained per 1,000 cubic feet of Newcastle coal gas. 7 to 12 per cent. CO is present in coal gas. CO has a greater diluting effect than H. H has a greater diluting effect than marsh gas. 10 to 13 gallons tar. and 13 to 30 gallons water are deposited by the time the gas reaches the outlet of the condensers. The idea which some engineers had of leaving the gas with the tar as long as possible was, that they believed the latter absorbed C0 2 and H 2 S, but the quantity of rich hydrocarbons also absorbed was not taken into account. Doing away with the condenser at Kichmond practically raised the illuminating power of the gas f candle. (T. May.) If gas be condensed below 45 F. the illuminating power is reduced, extreme cold having a detrimental effect on the illuminating power. The tar should be removed from the gas as soon as possible until the latter has been cooled to about 105 F. If the heavy tar oils and pitch are allowed to continue with the gas which is above 90 F. they absorb hydrocarbons from the gas. The gas enters the condenser main at about 122 F. The temperature of the gas should be gradually reduced to 90 F. before it enters the condensers. Condensation is required to remove all the tarry vesicles, and if this be done the temperature of the gas may be left to take care of itself as it will be cooled later on to atmospheric temperature. The condensers are best kept at the normal temperature of the air. If above or below this, the action of the purifier is interfered with. Much inconvenience in scrubbers and washers may be avoided by arranging condensers so that the gas is not cooled excessively. If the gas is not properly condensed before it enters the scrubbers the efficiency of the latter will be impaired. The richer the gas the greater the loss of hydrocarbons by exposure to low temperature. 256 GAS ENGINEER'S POCKET-BOOK. When the condensation is carried below 60 F., and friction is made to take place napthalene is frequently deposited. It is better to have napthalene in the works than in the district. Napthalene deposition in the works can be prevented by the use of liquor seals in place of tar, by quickly removing the tar from contact with the gas, and by long condensing or foul mains. Keeping up the temperature at outlet of condensers to 60 to 75 F. will prevent the deposition of napthalene at that point, but may send it into the district. It has been suggested to keep the temperature of the tar and liquor in the hydraulic main at about 100 F. so that the tar may retain a portion of the napthalene and bi-sulphide of carbon which it will not do at 160 F. If gas is thoroughly dried no napthalene is deposited. One method of clearing the napthalene from condensers is to run a small stream of liquor periodically into the first three or four compartments. Poor gas may tend to the deposition of napthalene as certain hydrocarbons have the power of carrying others of different specific gravity. A sudden cooling of the gas causes deposits of hydrocarbons and napthalene. Napthalene fuses at 176 F., boils at 423 F., is not soluble in water. To cure this trouble avoid wet coal keep your heats as even as possible. Tests for Napthalene, Dilute ammoniacal liquor with sulphuric acid, and if napthalene be present it becomes rose colour and smells of napthalene. Kedden liquor with nitric acid super-saturated with muriatic acid. If napthalene be present it will tinge a piece of firwood a rich purple. In order to dissolve napthalene in the condensers, Mr. Carpenter arranged a condenser to be reversible. When the outlet became partly choked it was made the inlet. The tarry vapours of the hot gas dissolved the deposit, which was quickly run off by the seals. The liquor from the condensers contains sulphocyanide, sulphate and hyposulphite among the fixed salts of ammonia. Analysis of Grade Gas leaving Condensers. (Butterfield.) By Volume. Per 100 Cubic Feet. NH 3 . . O'f>5 to 0-95 percent. C0 2 . . . 1-2 1-8 , H 2 S .. . 0-9 1-5 CS 2 . . . 0-020 0-035 , Cyanogen . 0-05 O'lO Napthalene . 0-005 0-015 200 to 300 grains 980 1470 570 28 50 12 950 50 100 35 TESTS OF GAS AFTER CONDENSERS. 257 Analysis of Crude Gas Leaving Condensers. (Professor Wanklyn at South Metropolitan Gas Co., Old Kent Road.) lu 1000 volumes SH 3 equals C0 3 equals . NH 3 equals 12*1 volumes. 15 3-6 Impurities in Condensed but Unwashed Gas. (Lewis T. Wright.) C0 2 H 3 S Grains per Cubic Foot. Volume per Cent. Grains per Cubic Foot. Volume per Cent. Newcastle Yorkshire Silkstone Derbyshire Cannels . 12 12 12 to 19 30 1-5 1-5 1-5 to 2-3 3-7 9 8 6 to 12 3 to 6 1-4 1-3 1 to 2-0 0-5 to 1-0 Tar made per ton, Gas Light and Coke Co., half-year to December, 1892, 10-58 gallons. Average Analysis of Gas (Newcastle Coal) after Condensers. H ... Methane . . . Carbon Monoxide . Hydrocarbons light C0 2 . . . . 47 per cent. 35 5 3-5 i-o 1-5 N H 3 S NH 3 . Cyanogen CS, . . Napthalene . . ( 3'0 per cent. 1-7 0-7 o-i 0-03 o-oi ;Butterfield.) NH 3 at outlet of condensers, say 300 grains per 100 cubic feet. GE. 258 GAS ENGINEER'S POCKET-BOOK EXHAUSTERS, ETC. By exhausting at 120 F., and passing gas direct to the scrubbers, an increase of from '5 to -75 candle resulted at Croydon. To relieve the consequent back pressure in scrubbers, warm water was tried, but nearly double the water was required to remove the ammonia from the gas. When byepassing the condenser the exhauster frequently becomes choked with sticky tar. Temperature of gas at exhauster usually 110 to 120 F. without fcmdensers giving 110 F. at inlet of condenser. Increase of pressure raises the inflammability of gaseous mixtures having a combustible gas as one of their ingredients. One of the evils of over-exhausting is the admission of furnace gases with the coal gas, and the consequent deterioration of the illuminating power of the latter ; another is the increase of fixed ammonia and reduction of free ammonia by the admission of air or furnace gases. 1 per cent, air has no effect on illuminating power. 2 per cent, air lowered 17-candle gas to 13*45 candles at Ramsgate. 5 10-59 Use Creosote Oil as a Lubricant for foul gas exhausters (Mr. Bacon, of B. Donkin & Co.). It is also said that castor oil forms the best lubricant for exhauster, and should have specific gravity '960 ; if below '955 it is impure. Another test of purity consists in adding zinc chloride, and then, if pure, the oil will turn yellow. Sperm oil may also be tested with zinc chloride, but this, if pure, turns milky. For lubrication of the working parts of the exhauster, a mixture of pure colza, tar, oil, and naptha has been found the best for the purpose. In the use of oil for lubrication uniformity of distribution is as important as the regularity of supply. A dry spot on a bearing will at once cause heating, and, if allowed to continue, cutting will be the result. No oil has yet been made that can economically lubricate all the journals of a mill. An oil running a heavy engine would not do to run a spindle or a fast-revolving dynamo. The former runs slowly, and has great pressure and strain on its journals, and consequently requires an oil that will not spread too quickly, but with low gravity and high viscosity. The latter needs a pure mineral oil, viscous and quick spreading, to enable it to enter into the closest parts of the bearing as rapidly as the speed at which it revolves necessitates. Mineral lubricants, or compounds of mineral and animal, are the safest, and produce the best results. Professor Thurston says, " Rancid oil will attack and injure machinery. Mineral oil does not absorb oxygen, whether alone or in contact with cotton waste, and cannot, therefore, take fire spontaneously ; animal and vegetable oils do. Mineral lubricating oils are used on all kinds of machinery : they are the safest and cheapest lubricants, and generally superior to COMBUSTION OP FUELS. 259 animal and vegetable oils and greases." A mineral oil flashing below 300 is unsafe. Gumming is due to the action of free acid upon the metal bearings of machinery. J. J. Kedwood remarks, " Mineral oil has the least action on metals, none on iron or brass ; tallow oil has most action on iron ; castor, olive, and lard oils have most action on brass ; rape seed has most action on copper." Heat of Combustion of Various Fuels. Substance. Average Heat from 1 Ib. Fuel. Thermal Units. Equivalent Evaporation from and at 212 F. per Ib. of Fuel, in Ibs. Water. Carbon (pure) .... Coal gas Coal gas, per cubic foot, at 62 F. Coal, good average quality . Coke Hydrogen ..... 14,560 17,800 630 14,700 13,500 62,000 15-07 18-43 0-70 15-22 13-87 64-20 Peat (dessi cated) . . . . Peat, 25 per cent, moisture . Petroleum oils (benzine, etc.) Petroleum crude .... Petroleum refuse, " astaki " . . Straw Sulphur "Wood, air dried .... Wood, dessi cated .... Wood, charcoal dessicated . 10,000 7,000 27,500 20,400 20,000 8,000 4,000 8,000 11,000 13,000 10-35 7-25 28-56 21-13 20-70 8-40 4-14 8-28 11-39 13-46 Theoretically, 11 Ibs. air is required per 1 Ib. coal to supply the necessary oxygen ; practically, 22 Ibs. air is required. 1 Ib. coke evaporates about 9 Ibs. water. 1 Ib. |th cubic foot water. 1 Ib. coal 9 Ibs. water. 1 Ib. slack 4 Ibs. Pounds of Water Evaporated per Ib. of Fuel. (B. Donkin & Co.) Breeze or dust gas coke as burnt on Perret's grate, 5| Ibs. water. Dust Welsh coal 8J Ordinary Welsh coal on ordinary grate . 9 Large gas coke 7 Another authority gives : Lbs. of water evaporated at 212 per Ib. of fuel. 7'4 Ibs. per Ib. breeze. 7-5 Ibs. per Ib. coke. 11-4 Ibs. per Ib. Welsh coal. 62 260 GAS ENGINEER'S POCKET-BOOK. Kelative Heating Power of Fuel, (Fritz.) Lbs. of Water Evaporated by 1 Ib. of Fuel. Fuel. Theoretical. In Steam In Open Boilers. Boilers. Anthracite 12-46 _ Coal 11-51 5-2 to 8 5-2 Charcoal. 10-77 6 6-75 3-7 Coke 9 to 10-8 5 8 Brown Coal . 7-7 2-2 5-5 1-5 to 2-3 Peat 5-5 to 7-4 2-5 4-5 1-7 2-3 Wood .... 4-3 to 5-6 2-5 3-75 1-85 2-1 Straw . . . . 3-0 1-86 1-93 Gas reduced to Ibs. coal . 4 6 In heating boilers the average amount of theoretical heating power of fuel that is utilised is only 47 per cent., the remainder being lost through imperfect combustion, radiation, and other causes. Evaporative Power of Fuel. Another set of tests gave : Ib. coke evaporates 9 Ibs. water (feed water supplied at 212 F.). coal 9 ;; slack 4 ;, ,, oak (dry) 4 pine 2J An average of 27 coals for fuel measured about 40 cubic feet per ton. Cost of evaporating 10 Ibs. of water from steam boilers. Breeze at 4/6 per ton = Q'OSGd. Coke at 12/- per ton = 0'097d. Welsh coal at 20/- per ton = 0-107d. Coke and coal are usually considered of equal calorific value, weight for weight. Boiler should be fed by small quantities and often, so that the draught of the chimney does not carry away the fuel improperly com- bined to form a permanent invisible gas ; smoke is only the re- condensing of gases that having been liberated by heat, have been allowed to cool back again and lapse back to their constituent parts before chemical union has arranged their molecules so as to render them invisible, when they enter the atmosphere and become absorbed in it. Andrew's patent fuel for boilers and retort furnaces consists of 40 gallons tar to 1 chaldron (21 cwt.) breeze, and sets hard in a few days. BOILER INCRUSTATIONS. 261 Average Water Consumption in Steam Engines. Non-condensing . . 25 to 40 Ibs. per I.H.P. per hour. Condensing . . . 18 30 Compound . . . 16 ,, 20 ., Triple expansion . . 13J 15 Heat feed water of boilers to 212 F. if possible. The usual course adopted by the engine and boiler minders is to inject tallow into the boiler to prevent priming. To Prevent Boiler Incrustations. Two ounces muriate of ammonia in boiler twice a week. Carbonate of soda. Frequent blowing off. Any fatty deposit on the interior surface of a boiler-plate greatly hinders the transmission of heat. (J. Hirsh.) Use caustic soda and soda ash for prevention of depositions of carbonate and sulphate of lime in boilers. 1 ounces pure caustic soda per 1,000 gallons for each grain carbonate of lime in feed water, and If ounces carbonate of soda (soda ash) per 1,000 per grain. Remove all sediment from boiler through blow-off cock every twelve hours. Ordinary feed water may be said to contain *05 per cent, solid matter, or 35 grains per gallon (in a boiler of 100 H.P. this equals 1 Ib. solid matter deposited per hour). By heating the feed water a large proportion of this may be kept out of the boilers. Test for Pure Water. 1. Evaporate a few drops on a piece of glass ; scarcely a trace of solid matter should remain. 2. Add nitrate of silver ; no turbidity (indicating chlorides or hydrochloric acid) should be produced. 3. Add chloride of barium ; there should be no turbidity (indi- cating sulphates). 4. Add oxalate of ammonia ; there should be no turbidity (indicat- ing lime). 5. Add hydrosulphuric acid; there should be no dark tinge (indicating lead or copper). Carbonates of lime and magnesia are deposited slowly at 150 F., but at from 280 to 300 the deposition is rapid (except 2 or 3 grains per gallons, which remains dissolved). Sulphate of lime is deposited at 307. 11 Ibs. air required theoretically for 1 Ib. coal burnt, but double this necessary with natural draught in boilers. The proportion of carbonic acid gas in the boiler flue should lie between 11 per cent, with bituminous and 15 per cent, with anthracite coals, with a small percentage of oxygen and no carbonic oxide. Heat at outlet of chimney may be reduced to 300 C. without injury to draught. When a jet photometer is fixed in the exhauster house, the gas should be purified by means of small lime and oxide purifiers before admission to the photometer. 262 GAS ENGINEER'S POCKET-BOOK. WASHING AND SCRUBBING. Gas should be free from tar before it enters the washers and scrubbers, or the efficient working of the latter will be impaired. Clean water scrubbers require from 2 to 3 gallons water per 1 .000 cubic feet of gas passed through them. Quantity of water required in standard washer scrubber 10 gallons per ton. This removed 241 grains NH 3 and reduced the C0 and 1I 2 S some 30 per cent. ; 50 square feet of wetted surface is exposed to the gas per cubic foot of machine. 13'7 gallons of water used in Kirkham Hulett and Chandler's washers per ton of coal carbonized and liquor produced was of 15 ounces strength. (King's Cross Works, 1881.) Water at ordinary temperature absorbs 700 times its volume of ammonia gas. Cold water will absorb about 1,000 times its bulk of ammonia gas. Water in scrubbers should not be lower than 50 or hydrocarbons will be deposited. At a temperature of 60 F. liquor of 14 ounces strengtli cannot reduce the ammonia in the gas it is in contact with to a lower degree than 54 grains per 100 cubic feet. (L. T. Wright.) At a temperature of 183 F. water will not absorb ammonia. Where there is plenty of washing and scrubbing room, water at 70 F. lias been used and good results obtained. If the water used to abstract ammonia is warm it wWl afterwards freely give off ammonia into the air. The water used in scrubbing has a distinctly deteriorative action on the illuminating power of the gas. If gas be lowered in temperature below 40 F. it has to be raised in scrubbers, and napthalene will be deposited in them. Average yield of ammonia per ton equals 6-8 Ibs.. or 1-5 per cent, by volume, or 467 grains per 100 cubic feet at outlet from retorts. About one-half of the total ammonia in the gas is removed by the scrubbers. NH 3 removed by condensation . . . 42-7 per cent. NH 8 first scrubber . . . 43-3 NH 3 second . . .14-0 (C. Hunt.) Ammonia is produced in a greater amount during the earlier period of the charge, and cyanogen during the latter hours. Lancashire and Yorkshire coal generally contains a larger propor- tion of ammonia than Durham coal. The ammonia in Midland Counties coal varies from G2-7 to 14T2 ounces per ton. Equal and thorough wetting of the material in the scrubber is necessary to ensure good working. With tower scrubbers extreme cold may have a detrimental effect on the illuminating power. SCRUBBING, 263 About 26 to 36 gallons of 10 ounce liquor are produced per ton of coal If gas be passed through a coke or clinker-filled scrubber, saturated with tar. it will injure the gas by as much as 2 candles. A lead-lined scrubber containing weak acid might be used for the elimination of the last few grains of ammonia, and thus water be saved. If liquor which has once passed through a scrubber be purified partly from H 2 S and C0 2 , it can be made to remove nearly all the H 2 S and much"of the C0 2 " when used again in the scrubber. In ammoniacal liquor, |ths of the ammonia is combined with C0 a and H 2 S and can be freed by boiling, the remaining ith is combined with hydrochloric, sulphuric, and other acids which cannot be freed by boiling. "lOOO cubic feet crude Newcastle coal gas contains about 8 cubic feet H 2 S, 25 cubic feet C0 a . About eight times the ammonia present in the crude gas would be required to eliminate all the C0 2 and H 2 S in the gas. A strong solution of ammoniacal liquor is required to effectually remove as large a proportion as possible of the H 2 S and C0 2 from the gas in the washers. Of the total volume of ammonia in the gas there will be 1-2 per cent, available for combining with the C0 2 and the hydro-sulphuric acids which will be able to remove 0'6 per cent, of C0 and 0*18 per cent. H 2 S. One combining equivalent NH 3 will absorb C0 2 or H 2 S to the extent of H to 1^ combining equivalent of one or both of these acid bodies. (Butterfield.) 100 volumes NH 3 combine with about 12J volumes H 2 S. 100 volumes NH 3 combine with about 50 volumes C0 2 . In a washer using 7 ounce liquor which thus became one of 14 ounce strength, the latter was found to contain 5,000 cubic inches of C0 2 and H 2 S equal to 357 cubic inches per ounce of strength, and the cost of dry purification by the dry process was reduced by 20 per cent. Maximum tension of ammonia gas in coal gas is about 0'45 inches mercury. When the quantity of water is reduced owing to smaller makes, the impurities in the gas travel further forward in the apparatus before being removed from the gas. Scrubbers remove about 2 grains CS 2 per 100 cubic feet. Ammoniacal liquor will remove ammonia from the gas in propor- tion to its own strength of ammonia only, therefore too strong ammonia used over the first scrubber may have the effect of increas- ing the quantity of the ammonia in the gas if the amount present before the gas enters the scrubber is less than the equivalent quantity in the liquor being used for washing purposes. In gas liquor of average strength there is generally from 60 to 70 per cent, by volume of carbonic and hydro -sulphuric acid in pro- portion to the volume of ammonia. 1 gallon 10 ounce liquor contains 4,704 cubic inches C0 2 and 1,362 cubic inches H 2 S, with 6,066 cubic inches other foul gases or equal to 57 cubic feet C0 2 , 16 cubic feet H a S. (G. Livesey.) 1 cubic foot NH S = 316-77 grs. 264 GAS ENGINEER'S POCKET-BOOK. The roost probable proportion of ammonia to C0 2 in gas liquor would be 2 volumes NH 3 to 1 volume C0 a , but with NH, and H 2 S, 1 of NH 3 to 1 of H S is more likely. Ammonia combines with CO 2 to form ammonium bicarbonate (NH 4 HC0 3 ). Ammonia combines with ELS to form ammonium sulphohydrate (NH 4 HS) ; or, Ammonia combines with C0 2 to form ammonium monocarbonate (NH 4 ) 2 C0 3 . Ammonia combines with H 2 S to form ammonium sulphide. Ammoniacal liquor is a weak solution of ammonium bicarbonate (NH 4 HC0 3 ), ammonium sulpho-hydrate (NH 4 HS), together with appreciable quantities of sulpho-cyanide (NELCNS) and thio-sulphate (NH,) 2 S 2 3 . (Lancet.} Analysis of Ammoniacal Liquor. (Professor Lewes.) Ammonia sulphide carbonate chloride thio-cyanate sulphate thio-sulphate ferro-cyanide; JFree Fixed Grammes per Litre. 3-08 39-lfi 14-28 1-80 0-19 2-80 0-41 Water will dissolve at 60 F. and 30 inches barometer, an equal volume of C0 2 . Water will dissolve at 32 F. If volume of C0 2 . Water will dissolve at 23 F. 4-37 volumes of H a S, and -001 volume of CS 2 . Water will dissolve at 60 F. and 30 inches barometer 783 volumes of NH 3 . Water will dissolve at 183 F. no NH 8 . 1 Twaddel equals about two ounces strength by distillation. Factor for Rendering Degrees Twaddel into Ounces Strength. (Lewis T. Wright.) Description of Liquor. Saturation. Distillation. Natural 2-18 2-54 1-80 2-43 caimel coal . 1-68 2-22 Final product . t . . 1-62 2-00 M J f 1-68 2-04 J )) * i 1-59 1-92 From clean water scrubbers 1-64 to 1-83 CYANOGEff. 265 Caking coals contain from 1-56 to 1-9 per cent. N, but of this amount only 11-59 to 15*72 per cent, comes off as>NH 3 during distillation. Yield of ammonia greatest at medium heats. (L. T. Wright.) . Of the total N in the coal, 14-5 per cent, passes off as ammonia, 1-56 per cent, as cyanogen, 48 '68 per cent, in coke, 35-26 per cent, in the gas. (Professor W. Foster.) The greater the proportion of fixed ammonia the less the purifying power of the liquor for the elimination of H 2 S or CO,. The liquor from the scrubbers contains carbonate and sulphide of ammonium, some free alkali and sulphocyanide, hyposulphite and sulphate. If sufficient ammonia be presented to the crude gas all the H 2 S, C0 2 , and C 2 S will be removed. if liquor could be made to give off the H 2 S and C0 2 which it has taken up in the scrubbers and could be used over again these impurities might be removed almost entirely by the ammonia. Hill's Process of " ammonia purification " consists of bringing the liquor, after use in the scrubbers, to nearly boiling point, when the CO 2 and H 2 S are driven off and the ammonia can then be used again in the scrubbers for the further elimination of C0 2 and H 2 S. By Hill's process the liquor was heated to 180 F.. when the C0 2 and H 2 S were driven off as follows : NH 4 HC0 3 = NH 3 + H 2 O + C0 2 , and NH 4 HS = NH 3 + H 2 S. To prevent the loss of ammonia the gases were passed through a scrubber supplied with liquor at 160 F. which it was supposed would arrest any ammonia gases. To obtain sufficient ammonia to remove all the C0 2 from the crude gas, the liquor has to be treated twice for the removal of the CO^ previously taken up. Cyanogen. The quantity of cyanogen recoverable from coal gas varies with the temperature of carbonization, from 5,000 grains with low heats to 10,000 grains with high heats per ton of coal. The most favourable temperature in the retorts for the formation of cyanides equals 2,200 F. Cyanogen is the gaseous compound of carbon and nitrogen. To Recover the Cyanogen. First remove all the NH 3 and then pass the gas through soda or potash in solution in presence of an iron salt, when from 4 to 4 Ibs. of crystallized ferrocyanide of soda or potash is recoverable per ton of coal. Spent products in gas works rarely contain more than 15 per cent, of ferrocyanide of potassium. (M. Perthuis.) Ammoniacal liquor made per ton, Gas Light and Coke Co. half year to December, 1892 : -279 butts per ton of 10 ounce strength by distillation, 266 GAS ENGINEER'S POCKET-BOOK. Impurities in Coal Gas after passing Scrubbers. (Butterfield.) H 2 S 500 to 800 grains x CO 2 700 to 1,100 L per 100 cubic feet. CS 2 30 to 45 ., J Average Composition of Gas after leaving Scrubbers. (Professor V. B. Lewes.) H 48-55 per cent, by volume. Methane 39' 70 Illuminants 3-30 C0 2 2-50 CO 2-00 O 0-45 N 3-50 1^ If the scrubbing is properly done, the gas should not contain more than 1-4 per cent. C0 2 , 0*3 per cent. H 2 S, and from 38 to 42 grains CS 2 per 100 cubic feet with no ammonia. Gas after leaving scrubbers contains about 400 grains H 2 S and 35 to 40 grains OS, and other sulphur compounds. There is generally some ammonia (say 50 grains per 100 cubic feet) at outlet of tower scrubbers, but if a washer-scrubber be in use the quantity will be reduced to 2 grains per 100 cubic feet. When water contains even traces of ammonia it will not take up the last grains of ammonia from the gas. The formation of cyanogen compounds is due to a secondary reaction between the ammonia primarily formed and the glowing carbon : C 2 + 4NH 3 = 2NFf 4 CN + 2H 3 ; this requires a high temperature. PURIFICATION. 267 PUF.IFYING. Gas loses about 3 per cent, by volume in passing through the purifiers, due to the elimination of the C0 (2'25 per cent.) and H 2 S (0-75 per cent). 25 cubic feet of C0 2 per 1,000 cubic feet gas reduces illuminating power about two candles, or, in other words, 1 per cent. C0 2 diminishes illuminating power 5 per cent., if gas is of 16 c. p. CO is present in coal gas to the extent of from 3 to 8 per cent. I'l per cent. S in coal equals 1*2 per cent, of H S in the gas. (Butterfield.) Crude gas contains about 8 feet of sulphuretted hydrogen per 1.000 feet of gas from Newcastle coal. Sulphuretted hydrogen is 1 part H, 16 parts S ; specific gravity is T178 ; 100 cubic inches weigh 36*51 grains. In ordinary use a purifier is turned off before it has ceased to remove H 2 S, the usual test being that the next box shows a foul test. Oxide of iron will at times absorb CS 2 . but will again give this off quite suddenly, possibly owing to the affinity of S for CS 2 , which can be disturbed by a slight increase in temperature. If gas containing CS 2 is passed through a mixture of sawdust and sulphur the quantity of CS 2 will be reduced 50 per cent. Oxide of iron, after fouling, contains some free sulphur and iron sulphide ; and revivification converts this into sulphur and hydrated iron oxide by the action of moisture and air. Analysis of Bog Ore (Dry basis). Ferric oxide 60 to 70 per cent. Organic matter 15 to 25 Silica 4 to 6 Alumina ...... 1 When in use the material would contain about 30 to 40 per cent, water. Bog ore is a hydrated sesquioxide of iron (Fe , O 3 , 3 H 0). Composition of Bog Ore : H 2 50 per cent. Hydrated oxide of iron, active . 20) q 9 inactive . 12} * Vegetable matter 18 ,, Bog ore when ready to place in purifier should only contain 25 per cent, moisture. Westbury Natural Oxide contains about 66 per cent, hydrated peroxide of iron, 28 earthy matter, 6 uncombined water. (N. H. Humphreys.) Bog ore contains 30 per cent. Fe 2 , O 3 , and 55 per cent, moisture. 268 GAS ENGINEER'S POCKET-BOOK. Analysis of O'Neill's Oxide. (June, 1875.) Water per cent 22-30 Fibre ......... 11-60 Peroxide of iron 65-42 Silica -57 Loss . -11 100-00 One cubic foot of oxide weighs 56 Ibs. "One ton of oxide should eliminate the H 3 S from 3,000,000 cubic feet of Newcastle coal gas, which contains about 8 cubic feet of H 2 ^ per 1,000." " An average quantity of oxide for 2,000,000 cubic feet of gas is ono ton when oxide only is used." " One ton bog ore should purify from 1,250.000 to 1,500,000 cubic feet of gas from H 2 S before becoming spent." It ia better when using new oxide for the first time to mix a little old with it, to reduce the percentage of moisture. A little old oxide mixed with new assists its action at first, as will also the presence of a slight quantity of ammonia in the gas. One equivalent of hydrated peroxide combines with about three equivalents of H 2 S. 36 parts of hydrated peroxide of iron will combine with 17 parts of H 2 S. Room must be allowed for expansion of material upwards when revivified in situ. Oxide should be laid in layers of from 12 to 18 inches thick. Best method of using oxide is 2 layers of 18 inches thick. (Hawkins.) Oxide of iron is laid as thick as 2 feet 6 inches in some purifiers. A thick layer of oxide, say 3 feet thick, will often have to be turned off, on account of back pressure, when only just put to work, but, as a rule, with thick layers of oxide no great increase of pressure need be feared if there be good scrubbing and washing beforehand. Oxide usually laid about 10 inches to 12 inches thick on the grids. Oxide should be laid about 10 inches thick to revivify. Gas should not be allowed to enter a purifier much above the temperature of the oxide therein^ The avoidance by every possible means of high temperatures in the purifiers, or during the revivification, of the spent material is advis- able. (M. Godinet.) Gas purified by oxide of iron is said to have a yellow tinge, while that purified by lime is whiter, the colour of the former being due probably to the presence of CO 2 . Reaction in Oxide Purifiers. Fe 2 3 H 2 + 3 H 2 S = Fe 2 S 3 + 4 H 2 ; or Fe 2 8 H 8 O + 3 H 2 S == 2 Fe S + S + 4 H 2 O. OXIDW PURIFICATION. 269 Action of air when revivifying upon Fe 2 S 3 + 4 H 2 0. 2 Fe 2 S 3 + 3 2 = 2 Fe 2 3 + 3 S a . 12 Fe S + 9 2 = 6 Fe 3 3 + 6 S 2 . Oxide (bog ore) should remove 1st time 16 per cent., 2nd 6 per cent., 3rd 5 per cent, sulphur. Another authority gives^- Reaction of Oxide of Iron, (70 o/ to 83 /o) Fe 2 3 H 2 + 3 H a S = Fe 2 S 3 + 4 H 2 0. (17 % to 30 o/o) ' = 2 FeS + S + 4 H 2 0. When revivifying Fe 2 S 3 + 3 + HO = Fe 2 3 H 2 + 3 S. Also hydrated oxide of iron removes H 2 S as per equation : Fe 2 3 3 H 2 + 3 H 2 S = 2 Fe S + 6 H 2 + S, and is revivified in the air as follows : 2 FeS + 3 H 2 + 20=30 + Fe 2 2 H 2 O + 2 S. H 2 S unites with the iron and forms sulphide of iron, the H, com- bining with in the oxide forming water. After use in purifier the oxide is in the form of sulphide of iron, the iron absorbs and leaves the sulphur in a free state. It is not advisable to use oxide containing more than 55 per cent, to 60 per cent, free sulphur, as its utility is impaired, but when revivified in situ it can be made to take up 75 per cent. Artificial oxides work best with from 20 to 30 per cent, moisture bog ores with 10 to 20 per cent. Oxide can be used until it has taken up 60 per cent, by weight of sulphur, but has no action upon C0 2 . New oxide, when revivifying, combines very rapidly with the in the air, causing rapid evolution of heat. Value of spent oxide should be sufficient to purchase all purifying material necessary for purification of gas from H 2 S. It has been found that by treating spent oxide with caustic, lime, and soda sulphate at a certain temperature, an increased yield of sulphocyanates and f errocyanides are obtained equal to about 40 per cent, above that obtainable by treatment with water. Analysis of Spent Oxide, (J. Hepworth.) Per Cent. H 2 14-0 S 60-0 Organic substances insoluble iii alcohol . . . 3'0 Organic substances soluble in alcohol consisting of calcium ferrocyanide and sulphaequinde, ammonium cyanidequinde, sal-ammoniac hydrocarbon . . . 1'5 Clay and sand 8'0 Calcium carbonate, ferric oxide, &c 13-5 ioo-o About one-half the total sulphur present in coal passes forward to the purifiers. The quantity of H 2 S requiring to be removed by the purifier may range from 200 to 2,000 grains per 100 cubic feet 270 GAS ENGINEER'S POCKET-BOOK. Order of Value for Purifying Coal Gas of the Principal Limestones of this Country, (Hughes.) 1. The white chalk limestone of Merstham, Dorking, Chaiiton, Erith, and other parts of the chalk range surrounding the metropolis. 2. The grey chalk limestone, from the lower beds of chalk. 3. The blue beds of the upper and middle Oolites. 4. The lower white and grey limestones of the Oolites. 5. The most calcareous and crystalline beds of the carboniferous or mountain limestone, colours grey and bluish. 6. The magnesian limestone of Yorkshire and Derbyshire. 7. The white lias limestone. 8. The blue lias limestone. 9. The Silurian limestone of Wenlock, Dudley, &c., and the coraline limestones of Plymouth and the neighbourhood. Theoretical value of chalk when made into lime is 100 Ibs. chalk equals 56 Ibs. CaO as per equation : CaCO 3 =Co 2 + CaO. 100 = 44 + 56 In practice 1 ton chalk makes on an average 1 yard lime ; (13,596 tons chalk made 13,300 yards lime). (Actual experiment, 17th May, 1893.) Lime. 25 striked bushels or 100 pecks equals 1 hundred of lime. 46.656 cubic inches, 1 cubic yard, or 27 cubic feet containing 21 bushels, equal 100 lime. ] bushel of quick lime weighs about 70 Ibs. ] cubic foot stone 54 1 cubic yard quick 1,460 1 ton equals 32 bushels. About 40 Ibs. of lime are required to purify a ton of coals in large works. Lime used in large and medium sized works in purification with oxide or other supplemental method ranges from 3'3 to 5'5 cubic yards per million cubic feet of gas. By the rotation method of purifying, 1 yard unslaked lime is required per 35 tons of coal used. 165 Ibs. Irish unslaked lime will clean about 35,000 cubic feet of gas. Quantity of lime required to extract C0 2 , about 3'3 yards per million cubic feet. Chalk lime is best for purification of gas from C0 2 . Lime often contains 5 to 20 per cent, of earthy matters which may cause it to become caked in the purifiers. LIME PURIFICATION. 271 Lime ready for the purifiers generally contains 30 to 10 per cent, of water above that required for the making of hydrate of lime. 1 bushel quick lime increases to 2^ when slaked, and this should purify 10,000 cubic feet of gas. (Richards.) Caustic lime when slaked about doubles in bulk as CaO + H a O equals CaH 2 2 . 28 parts of lime combine with 9 parts of water to form hydrate of lime or slaked lime. 28 parts of pure lime will combine with 22 parts of C0 2 . 28 parts of pure lime will combine with 17 parts of H 2 1S. 74 parts by weight of pure hydrated lime should combine with 44 parts of C0 2 or with 34 parts of H a S. Sometimes when lime is used to remove C0 2 , H 2 S and C8 2 an oxide vessel is used last, to act as a catch purifier to take up any H 2 S that may be driven off from the sulphide vessel. When lime only is used for purification the sulphur is wasted. Wet lime will purify double or treble the gas dry lime will. (S. Anderson.) Dry CO when present in a purifier containing dry hydrate of lime will not combine with it, but the addition of moisture causes the CaOH 2 + C0 2 to become CaOC0 2 + H 2 0. When water is added to lime" calcic hydrate is formed as per equation : CaO + H 3 = CaOH 2 0. Excessive water in the lime will cause the latter to cake and then impede the passage of the gas. Lime usually laid about 4 inches thick on the grids. 1.650 Ibs. of lime will take up about 425 gallons of water when being mixed up for the purifier, or about 1 gallon of water to 4 Ibs. of lime. Lime should be slaked two or three days prior to use in purifiers or it may cake ; slaking increases the bulk about 2^ times ; it should be as pasty as possible, and take the form of nodules about f inch to 1 inch in diameter. Dry lime is not so porous or so efficacious as a purifying material. Mr. P. Egner (U.S.A.) proposes to prepare lime for purifying as follows : a thin layer, 4 or 5 inches deep, of unslaked lime should be laid out, and nearly the whole quantity of water poured over the lime. As the lime slakes it is turned over with long pronged rakes, then one-tenth of its bulk of screened coke breeze added and thoroughly mixed and moistened until a handful will stick together when tightly squeezed Removal of Carbonic Acid. Here lime purification should be adopted ; the material to be hot and divided in several layers. No special system of revivification need be followed. 1 Pressure thrown by a lime purifier with sieves covered with from 12 to 15 inches of lime should never exceed 1 inch during its working. 272 GAS ENGINEER'S POCKET-BOOK. Pressure thrown by 8 layers of lime 10 inches thick has been as low- as 1J inch for a considerable period. Lime is usually placed in layers of 4 to 6 inches thick. Approximate action of lime on H 2 S in purification is expressed probably by the following equation : CaOH 2 + H 2 S = CaS + 2 H 2 Lime meeting C0 2 in gas without H 2 S forms calcium carbonate CaO + C0 a = CaC0 3 Lime first attacks both the C0 3 and H 2 S, forming carbonate and sulphide of calcium, but later the"C0 2 , having a greater affinity for the lime, drives off the H 2 S and forms carbonate of calcium only. When gas containing C0 2 and H 2 S meets lime : CaH s O f + 2 H 2 S = CaS, H 2 S + 2 H 2 ^ " or CaH 2 O a + H 2 S = CaS + 2 H 2 f formed simultaneously, and CaO + C0 a = CaC0 3 afterwards the CaS + C0 2 + H 2 = CaC0 3 + H 2 S the H a S being driven forward owing to the greater affinity of the C0 a decomposing the CaS ; but if air is admitted a certain portion of the H 2 S is converted into free sulphur and it cannot then be sent forward. About 70 Ibs quicklime is required per ton of coal in small works. 130 ,, ., cannel. 1 bushel quicklime weighs about 70 Ibs. = 1'3 cubic feet. 1 cubic foot chalk lime ,, 45 = 771 bushels. 1 cubic yard ,, ,, 1,460 = 20.9 1 ton ,, measures ,, 32 bushels. Lime ready slaked for the purifiers should weigh about 90 Ibs. per bushel. Mr. Forstall has suggested passing the slaked lime through sieve with 1 inch square mesh set at an angle of 70 with the floor, and the lime should not be wet enough to cling to the sieve. If lime be allowed to become too dry and powdery C0 2 will speedily slip, and if too wet the result is not satisfactory ; both extremes should be avoided. If cold gas be introduced into a hot material the latter is rendered powdery, and if hot gas is introduced into a cold material it is made too wet. Removal of the Sulphur Compounds. The cost of removing the sulphur compounds may be taken aa over Id. per thousand cubic feet. Where oxide of iron is used there should be a large purifying surface and prolonged contact with the purifying material, which should be in one or several layers according to the use or non-use of SULPHUR COMPOUNDS. 273 inert materials. Where revivification is effected in the open air, the material should be heaped up on its removal from the purifiers, and, as soon as it becomes heated, spread in layers from 8 to 12 inches thick. Where continuous revivification is employed the volume of air or oxygen should be injected without interruption and in exact proportion to the make of gas, the material to be kept warm and moist. In the case of purification by lime the material should be divided into several layers and used cold if it is desired to retain more of the sulphide of carbon, otherwise hot. Oxygen should be employed for revivification. Quantity of Sulphur Compounds from Same Coal. Yield of Gas Sulphur per 100 Cubic Feet per Ton. other than H2S. grains. 6,893 ...... 13-9 8,370 ...... 19-1 9,431 ...... 26-7 10,772 ...... 36-9 11,620 . . . . . . 44-1 If C0 2 be allowed to pass into a sulphided lime purifier it will liberate some of the H a S and CS 2 already taken up and form car- bonate of calcium in its "place. If H 2 S be allowed to pass into a properly sulphided lime purifier it changes the monosulphide to a polysulphide, which has no effect upon the CS 2 . Of the 45 grains S. other than H 2 S in coal gas per 100 cubic feet, the C0 2 purifiers remove 10 grains, the sulphided purifiers remove 25 grains. Carbon bisulphide (CS 2 ) is usually removed by a lime purifier, through which a quantity of gas free from C0 2 but containing H 2 S has been passed, the H 2 S combining with the lime to form sulphide of lime, which latter will remove practically all the CS 3 . The removal of the sulphur compounds is not rendered more certain by the admission of 1 to 2 per cent, of air at Nos. 3 or 4 purifiers at Kotherhithe. (A. F. Browne.) Probable action in sulphided lime purifiers. CaS + CS a =CaCS 8 or, CaSH 2 + CS 2 == CaCS 3 +H 2 O or, CaS 5 + CS 2 = CaS 2 CS 2 + S 3 The calcium pentasulphide may also combine with the admitted in the air thus : or with C0 2 thus : . G.E. C0 2 274 GAS ENGINEER'S POCKET-BOOK. Laming material consists of sulphate of iron, 250 kilogrammes ; slaked lime in powder, 4 hectolitres, inert material, 7 hectolitres. The stability of the sulphide of lime, as measured by the action upon it of C0 2 , depends largely upon the temperature at which the sulphide is formed. The energy of union as between calcium sulphide and CS 2 is sharper and much more complete when the sulphide is prepared from hot lime, and is maintained at about the temperature of 75 F. Sulphide so made and used is said to have 30 per cent, greater efficiency ; and by chilling the vessel the efficiency can be reduced to nil. A very small quantity of C0 2 passing into a sulphide vessel materially decreases the efficiency. Weldon mud is a bye product from the manufacture of bleaching powder with lime and air, and consists principally of hydrated oxides of manganese (Mn0 2 and MnO) and of calcium. Weldon mud will absorb about four to five times the H 2 S that oxide of iron will, forming sulphide of manganese and water. Weldon mud equals about 52 per cent, water and 26 per cent, manganese dioxide, and should remove 28'1 per cent. S first time, 16*7 per cent, second time, 5 -8 per cent, third time. About 1 per cent, of air is considered best with Weldon mud when it is used for the first removal of H 2 S. About 10 to 15 grains H 2 S per 100 cubic feet is contained in the gas when it reaches the check purifiers, where lime or Weldon mud is found more active for such small quantities than oxide of iron. Weldon mud with about per cent, of air has continued active in this position for two to three years, and is said to represent a labour saving as against lime of 1 to 16 ; the pressure thrown decreases with time, whereas with lime and oxide it increases. Comparative quantity of oxide shifted at Beckton per 100,000,000 cubic feet gas made, 503 cubic yards as against 50 cubic yards of Weldon mud ; this refers to the material used in the primary elimination of H 2 S. In the all lime purifying method about 1J per cent, air is about the best quantity. The use of air greatly mitigates the bad smells given off by oxide when it is first removed from the purifiers, and doubles the length of time the purifiers will last without recharging. Air used with lime purifiers will cause the sulphur taken up by the lime to be converted into free sulphur to the extent of 10 per cent., instead of being driven off by the C0 2 . The use of air (1 per cent.) in purification enables the oxide to absorb some 25 per cent, sulphur before it need be removed for complete revivification. Purifiers by the air process have been filled with oxide, and not again discharged until the material contains nearly 60 per cent, of sulphur. More than 3 per cent, air not only reduces the illuminating power, but is inclined to cake the oxide and to raise the temperature of the material. The admission of air or oxygen to the purifiers effects an oxidation REVIVIFICATION IN SITU. 275 of the sulphur compounds of the lime, and sulphur is deposited as such in the foul lime. (Butterfield.) Air may be used in a sulphide vessel to reconvert a polysulphide into a monosulphide, or to render a box sulphided at a low tempera- ture active. Steam, when used to inject air into purifiers, has been found to prevent the caking of the oxide ; it has been suggested to introduce it at the inlet to first purifier so as to raise the temperature to 100. Revivification by steam jet in situ may set fire to the grids. Mr. Carpenter admits 1 per cent, air into the third or fourth purifier and thus obtains the desired effect on the ones required for the removal of the sulphur compounds. When air is used (2 per cent.) to aid purification in oxide vessels the use of ammonium hydrate (ammoniacal liquor 4 Twaddel) sprinkled on the oxide before use is found to increase the life of the charge from 80 to 100 per cent. (R. G. Shadbolt.) Two and a half per cent, air used in purification lowered 17'3 candle gas to 13*45 candles. Three per cent, air used in purification lowered 17*3 candle gas to 13-04 candles. Five per cent, air used in purification lowered 17'3 candle gas to 10-59 candles. Seventeen and a half per cent, air used in purification lowered 17'3 candle gas to 1-0 candle. An arrangement for pumping into the gas at the inlet of the puri- fiers 3 per cent, air carburetted with tar of specific gravity 1-196, kept at a temperature of 170 by a steam coil, was patented by Mr. Hawkins, to remove the loss of illuminating power occasioned by the use of such a large quantity of air. The specific gravity of the tar after leaving the carburettor was 1'218. The only objection appeared to be the possibility of a deposit of napthalene in the mains during severe winter weather. The illuminating power appears to have been maintained throughout the district. The quantity of air necessary, according to theory, for continuous revivification of oxide is 2 per cent, air for 1 per cent. H 2 S. A slight margin in excess is, however, necessary in practice for safety. It is said that the higher temperature in a purifier, due to the increased chemical activity of the purifying material when air is used, prevents the deposition of some of the valuable hydrocarbons, which in the ordinary way would be condensed ; the napthalene on the under side of a purifier cover in winter clearly showing that such a deposition will take place. Advantages claimed for the use of with oxide of iron purifi- cation are Almost complete revivification of oxide in situ ; increased illuminating power ; greatly augmented percentage of sulphur in spent oxide, and consequent higher market value ; the purification more efficiently conducted, with half the purifying space and two-thirds of the material ; a corresponding saving in capital and labour. Lime can be wholly used in conjunction with oxygen for the puri- fication of gas. By the regulation of quantity of to quantities T2 276 GAS ENGINEER'S POCKET-BOOK. of impurities sulphur compounds can be removed. Purifying space and plant now required for lime reduced by more than one-half, lime used by nearly one-half, and labour in proportion. Auxiliary oxide of iron purifiers are rendered unnecessary. Very considerable saving is caused by improvement in illuminating power. Sulphur deposited possibly recoverable. (W. A. Mel. Valon.) With oxygen and lime only and average of 620 grains S per 100 cubic feet at inlet, 2 cubic yards lime per million cubic feet kept sulphur compounds down to an average of 6 to 8 grains per 100 cubic feet, and the illuminating power maintained at 16*5 candles. (W. A. Mel. Valon.) Proportion of Oxygen Required for Purification. 0*1 per cent., by volume of oxygen for every 100 grains, H 2 S per 100 cubic feet removes all the H 2 S and C0 2 , and reduces the sulphur compound to 7 or 8 grains per 100 cubic feet of purified gas. One foot pure is sufficient to remove 1 ,000 grains H 2 S in the crude gas; or *1 per cent, by volume of per 100 grains H $ per 100 cubic feet. One half the volume of H 2 S in the gas is required of oxygen to revivify the oxide in situ. No increase in heat is found in the oxide when using 0. When oxygen is used with lime purifiers the H 2 S first taken up by the lime is not expelled again by the C0 2 , but the S is thrown down in the form of grains of pure sulphur, leaving the lime as active for the C0 a as if no sulphur had been retained. To Prepare Oxygen. When air is compressed over water, the components of the atmos- phere are taken up in direct ratio of the pressures employed. On releasing the pressure, there is proportionally more oxygen in the evolved gases ; by repeating the process eight times 97-3 per cent, oxygen can be obtained. Composition after Successive Pressures. N. 79 66-67 52-5 37'5 25-0 15'0 9-0 5-0 2-7 O. 21 33-33 47-5 62'5 75'0 85'0 91-0 95-0 97'3 For a material to revivify in situ it must have a strong affinity for O, so as to combine with it energetically as it passes through the gas. Cyanogen. It would appear from the reactions expressing these changes that the cyanogen exists in coal gas exclusively in the forms of cyanide and sulphocyanide of ammonium. Fsrj-ocyanide of iron is formed if cyanogen and ammonia in only small traces are allowed to get to the oxide purifiers ; this reduces the activity of the oxide for the removal of H 2 S. A large portion of the cyanogen combines with the iron in the purifiers to form a ferrocyanide or Prussian blue, but the quantity is reduced if first passed through lime. CYANOGEN. 277 Average per cent, of sulphocyanic acid, ammonia, and potassium ferrocyanide obtained from 12 German gasworks HCNS = 2-62, NH 3 =l-87, K 4 FeCy+ 3aq=5'l. One ton of coal by the Glaus ammonia process yields J Ib. Prussian blue and If Ibs. copper sulphocyanide. Leybold found cyanogen equal to about 4 Ibs. of ferrocyanide in 10,000 cubic feet of gas, of which nearly 95 per cent, remained in the scrubbed gas. When lime is used for purifying the gas, the cyanogen is lost ; and if iron be used the cyanogen is converted largely into sulphocyanide in which form it is not so readily available. But when the gas after it leaves the scrubber is brought into intimate contact with precipitated oxide of iron, suspended in an alkaline solution, as recommended by Knublauch, the cyanogen is easily obtained as ferrocyanide, almost free from sulphocyanide. Removal of the Cyanogen Compounds. To ensure material rich in Prussian blue keep the stuff very moist at a low temperature, have a large purifying surface and long con- tact. When revivifying in the open air spread the material in very thin layers kept quite moist ; but if in situ inject cold air saturated with moisture at great speed. In the case of continuous revivifica- tion the opposite process must be adopted, owing to the presence of less sulphide of iron in the purifiers. Oil gas tar will remain on the sides of purifier covers, also petroleum oil. Composition of Purified Illuminating Gas. COMMON GAS. Authority. Permanent Gases, H, CO, He, &c. Illuminating Compounds or Light Bearers. Impurities, NH;, C &C.' Bunsen . . . ' Letheby (12 candle gas) Odling ,j . . . ;, . . . ' ,, . . . . . . ? . 87-12 93-00 96-42 93-92 89-83 90-03 96-01 6-56 3-80 3-05 3-56 3-67 3-63 3-53 6-42 3.20 0-53 2-53 6-50 0-40 0-46 CANNEL GAS. Letheby (22 candle gas) Odling .... Two analyses of water \ gas as sold in New York / 84-05 88-00 / 78-90 \SM6 13-00 10-81 15-29 15-29 2-50 1-19 4-8 3-5 278 GAS ENGINEER'S POCKET-BOO^. Composition of Purified Coal Gas. (Professor V. B. Lewes, 1890.) Per Cent. H 47-9 Illuminants, ethylene series . . . 3*5 .. benzene . . . 0'9 ., methane ... . . 7'9 Methane . . . " . . . 33-3 CO 6-0 C0 3 0-0 O 0-5 N 0-0 100-0 5,000 cubic feet lime will absorb about 5 tons H 3 S. This sulphided lime will absorb about 3 tons CS a . STORING GAS. GASHOLDERS (CARE OP). It takes a considerable time for the diffusion of gases of different densities even when of great difference of density, when in conditions usual in gasholders. Diffusion of Gases, The velocity of diffusion of different gases is inversely propor- tional to the square roots of their densities. Density. Air=l 1 (V/Density. Velocity of diffusion. Air = 1 Hydrogen . Nitrogen. . . . Oxygen Carbon dioxide . . 0-06926 0-97130 1-10560 1-52900 3-7790 1-0150 0-9510 0-8087 3-830 1-014 0-949 0-812 (Graham.) Gases of different specific gravity will mix in time, but, owing to the temperature of either the incoming gas or the heat of that in the holder, the mixing may take a considerable time, the warmer gas keeping to the top of the holder. From the heat of the sun, the crown of a gasholder becomes so hot that it cannot be touched with the hand, being at least from 113 to 122 F. (W. Ley bold.) The contact of ordinary coal gas with water is found to cause a rapid diminution in illuminating power. (Irwin.) Carburetted water gas stored in a holder for 17 days, lost 1 candles in value at Blackburn. Napthalene in gas holder inlet pipes is usually found to commence at and continue below the level of the surrounding water. Do not lower a telescopic holder in a gale so as to leave the upper lift only exposed. As the centre of gravity is very near the crown, it is the more easily overturned, while, if the second lift is out of the water its weight brings the centre of gravity considerably lower. Frost has been known to cause the sides of brick tanks to bulge inwards and prevent the holder moving up and down. Fainting Notes. Gasholders should be first made clean by scrubbing and brushing with wire brushes, any bubbles of the old paint being scraped off with an old file sharpened at the edge. Before painting a holder well scrape the old paint and remove old blisters and scales which might cause a lodgment of water and consequent oxidation of the plates. 280 GAS ENGINEER'S POCKET-BOOK. With paint, too much oxide is not good for the oil which is then oxidized too quickly and rendered natureless, so that the paint eventually powders off. (Wood.) A Coating for Gasholders. Mix and raise to boiling point, 1 gallon of tar and Ib. asphalte, then add 1 pint coal naptha and Ib. tallow. Use warm. The outer surface of gasholders may be covered with paint, or tar mixed with tallow, and it has been proposed to do this in the spring and also autumn each year. Oil gas tar is an excellent paint for gasholders. Tar for painting should only be raised sufficiently high in tempera- ture to drive off all the water, should be fluid when cold, too'thick for use, and can be thinned with turpentine, 1 turps, to 4 tar ; 1 gallon will cover 64 square yards of metallic surface. Bed lead sets harder and sooner than white lead. Contents of crown, to find : Square the radius of the holder, multiply this square by 3 ; to the product add the square of the rise and multiply by -5236. In filling the holder with gas it is best to use a high-class coal, and so compensate for the air in crown, as it is difficult to expel the latter. DISTRIBUTING GAS. 281 DISTRIBUTION. Mains. Services. Meters. Quantity of gas, in cubic feet, discharged per hour by any main can be found as follows : Where h = pressure of gas in inches of water. d = diameter of pipes in inches. S = specific gravity of gas (air = 1) L = length of pipe in yards. (Dr. Pole.) Another rule is (Molesworth's Pocket Book.) And another is x= 1,000 ^/pL (Spon's Pocket Book.) The first is the most correct. Flow of Air in Pipes. (Hawksley.) Velocity in feet per second = head in inches of water x diameter of pipe in feet length of pipe in feet Head in inches of water = length of pipe in feet X velocity Io6,800 diameter of pipe in feet Contents of pipe = square of diameter X '7854 x length ; contents in cubic feet X 6-26 = gallons. Weight of cast iron pipe = K (D 2 d 2 ). K = (for cast iron) 2-5. Flange equals, say. 1 foot of pipe in weight. In a 24-inch pipe delivering 240.000 cubic feet per hour into one 18-inch pipe and two 14-inch pipes at a distance of about 2,000 yards 47 20 the pressure was reduced from - to 282 GAS ENGINEERS POCKET-BOOK. Capacity of pipes. 500 750 1000 1250 1500 16,000 15,000 14,000 DELIVERING POWER OP PIPES. Capacity of pipes. 283 9" 9" -V \ ja^Av jo S9iput ut sojnss 5 55 55% H 5 tei-le 55 H ts 5 N Cl rt ci M -H w N N \ \ \ 1 jj- TjflJ- ke \ \ n / 1 t m - - - - - ~ \ \ \ . \ \ \ \ \ V \ \ | . \ \ ^ \ ^ \ ^ \ E \ V, ^ ^ \ ^ V . \ \ t \ s. j 5 f"\ * ^ \ \ j \ V \ \ \ \ \ S^ ^ ^ i \ \ \! \ ^ g \ \ \ \ \\ \ V y \ \ \ \ s \ ^ ^ ^ \ \ s s. ^ \\ \ s < ^ l Jj ^ X v ^ 5 \ \ \ \ s 5 "" ^ 5 \ \ s, s ^, ^ X, v^ < fc \ ^ s S^ \ v *> ^ s^ s s. v r \ s \ X \ -^ \ ^ v Ky S f ^ "" ^ *- L^ g f k k s ( x k - ^ \\ s 5 ^ X t v E f^ s\ \ 5 " >s "^ B ,\ s sN 1 x ^ s^ x, > N N s ^ -V \ KS,^ ^ k^ "^s. ^ \ \ > -^ _ ^^ ^. ^ *--, ^ i 5 "^ r- ^> *\ ^ __ ^ 0-. *--, =: >, -^ - ^ t=T ^ ^ i" ^ s -^ ^: - - _ _i _ 250 500 750 1000 1250 Length in yards. i75o 284 GAS ENGINEER'S POCKET-BOOK. Capacity of pipes. 250 500 750 1000 1250 1500 1750 2000 4" 2" 4" 10. tr I i" .. ?? LEAD REQUIRED FOR JOINTING. 285 Relative Carrying Capacity of Gas Pipes. (Compiled from Tables by Norwalk Iron Co., U.S.A.) Inches. 24 = 1-00 . 12 = 0-17 10 = 0-10 . 8 = 0-06 7 = 0-04 . 6 = 0-03 5 = 0-0189 4J = 0-0141 . 4 = 0-0102 3 = 0-0069 . 3 = 0-0045 2i = 0-002835 2 = 0-001485 . IA = 0-000810 IA = 0-000450 . 1 = 0-000225 Comparative Areas. . 1-00 . . 0-25 . 0-175 . . 0-111 . 0-085 . . 0-0625 . 0-0434 . . 0-0351 . 0-0278 . 0-0212 . 0-0156 . . 0-0108 . 0-0069 . . 0-0039 . 0-00272 . 0-00173 High Pressure Gas Delivery. (F. H. Oliphant.) Cubic feet per hour = 42 a .1 1 P and p are gauge pressures at intake and discharge ends of pipe plus 15 Ibs., 1 is length in yards, a for different sizes of pipes is : Diameter Diameter Diameter Diameter inside. a inside. a inside. outside. Cl 0-25 0-0317 4 34-1 14-25 15 863 0-50 0-1810 5 60 15-25 16 1025 0-75 0-5012 6 96 17-25 18 1410 1-0 1-0000 8 198 19-25 20 1860 Rivetted or cast iron pipes. 1-5 2-9300 10 350 20 2055 2-0 5-9200 12 556 24 3285 2-5 10-3700 16 1160 30 5830 3-0 16-5 18 1570 36 9330 286 GAS ENGINEER'S POCKET-BOOK. ,... GO- Weight SO Ibs. each. -#-Jr> Weight- /20/6s.each. 9' 01 5" J 6 . _. a* 0" j , 4" W*iyhr2?0.0.*act>. A !(-*-> ty \i ( 'J, & '> l ^ { *L ! V ** - -9' 0" Weiyht 2? 2.0 aocA. __y Trf p- r - ^i i j 23 "> ** a^ i 7" * j_ Weiyht3? O.O.each. 4 i : i i j y^ uiu^ 8* * Weight 3* 2.0.each. r^/^ i i 'i 4 5 i* ^ ^""^asi^ ---. 9" g- tt i/ Q >! DIMENSIONS OF PIPES. 287 288 GAS ENGINEER'S POCKET-BOOK. 3 ?, Jp H J! Mains. 48-inch Socket joint requires 90 Ibs. lead and 8 yards yarn. 1H 72 6 10S ?f 60 ,. 5 90 ,, ., 48 4 72 32 18-2 ,. 14-9 ,. 11-5 10-4 8-2 7-7 6'5 ., 5 4 2'6 Flange joints made with wrought-iron ring J-inch thick placed between flanges and bolted up, afterwards run with lead and set up. Yarn weighs 1 qr. 23 Ibs. per 250 yards equals 1 coil. All mains above 6 inches diameter should be cast vertical so that a few inches at the end may be cut off and any porous part removed. Cast iron pipes should be of close grain and equal thickness throughout. This can be found by rolling them on two rails or metal edges and noting if there be a heavy side by the pipes always rolling to one position, and they should emit a bell-like sound when tapped with a hammer. They should be tested to from 90 to 130 Ibs. per square inch, and tapped while under pressure ; if water is seen oozing from cracks or flaws the pipes should be rejected. Weight in Founds and Depth of Lead for Ordinary Lead Joints. 48 Flange 36 ., Socket . 36 Flange 30 Socket 30 24 Flange , Socket , 24 Flange , 18 5 Socket . 12 5 J> V 11 1 J 10 ) 9 . ? 8 J 5 J 7 J . , 6 5> 5 5 J 4 5> > 3 >J J> Diameter of Pipe. Weight of Lead. Depth of Lead. Diameter of Pipe. Weight of Lead. Depth of Lead. Inches. Lbs. Inches. Inches. Lbs. Inches. 2 If }i 12 18i 2f 3 2f If 13 21 2f 4 4 If 14 23J 2| 5 5i 1* 15 26 2* 6 7 2 16 28 2i 7 8| 2 17 31 2i 8 9 10* 12* 2* 2| 18 19 32 34 2f 2| 10 1H 2i 20 35 2 11 16i 2* 24 48 3 For pipes up to 8 inches in diameter the lead is taken at inch thick, and for pipes from 9 inches diameter upwards the lead is taken at inch thick. PIPE JOINTS. 289 Dimensions of Cast Iron Pipe Flanges to bear 75 Ibs. Pressure. (Briggg.) lit Thickness 1 of Body. 1 Thickness 1 of Boss. S- tcj r Thickness I of Flange 1 Finished. J i!.c 33 ofe o -0* Diajneterofl Bolt Holes. 1 Outside 1 Diameter 1 of Flange. 1 Diameter 1 of Bolts Inside. Number of 1 Bolts Diameter j of Bolts. | 3 328 40 1-25 50 56 55 6* &i 4 ^ H 3U 42 1-2S 51 57 61 4 4 ft 4 354 .43 1-30 53 59 61 8 5 I 5 380 46 1-35 56 63 61 9 7* 6 ft 6 406 49 1-40 60 67 68 10j 6 I 8 453 55 1-50 66 74 68 12* ]OA 8 # 10 510 61 1-60 73 81 81 15 13-5- 10 1 12 563 67 1-70 80 89 93 17f 15ft 10 i 16 6(57 79 1-90 93 1-01 93 22 19* 14 i DLme:i3lons of Socket Joints. (Unwin.) Where t = thick n-jss of: pipe and d = diameter of pipe. * to 0-025^ + 0-6 =0'045fl? + 0-8 =0'01rZ + -25 to O'Ol^ + '375 I = 0-09d + 2| to 0-ld + 3 and J = Thickness of Pipes for 90 Ibs. Pressure per Square Inch up to 20 Inches Diameter, and up to 75 Ibs. Pressure per Square Inch up to 60 Inches Diameter. Ins. Ins. Ins. Ins. Ins. Ins. Ins. ins. Ins. Ins. Ins. Ins. Diameter of Pipe . 4 8 12 16 20 24 30 36 42 48 54 60 Thickness . . f 7 16 i Ta i } lo- t K i tt 1 G.B. 290 GAS ENGINEER'S POCKET-BOOK. Dimensions of Turned and Bored Pipes in Inches. Dia- meter of Pipe. Thick- ness. Depth of Socket. Thick- ness of Rim. Thick- ness of Socket. Dia- meter of Pipe. Thick- ness. Depth of Socket. Thick- ness of Rim. Thick- ness of Socket. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. 2 * 3 i A 11 $| m 3 I 3f -1 1 12 4J l 4 & 4 H 13 I 4i 11 TS 5 6 f 4 4* if H ? 14 15 I 5 2 If 2 l" 5 7 * I* 1 16 1 5 2 1 8 * 4* M g 17 I 5 2* IJL 9 10 i if if 18 20 tt y 4 24 if THICKNESS or RIM THICKNESS or SOCKKT THICKNESS Weight of Socket 2 inches diameter = 4-54 It 2* = 6-64 3 := 11-2 4 : 14-45 5 : 21-0 6 , 24-8 7 33-0 8 ^s 37-36 9 41-7 10 . 52-30 11 I = 57-27 of Cast Iron Pipes. 12 inches diameter = 90-54 Ibs 15 = 112-36 18 20 21 24 30 36 42 48 = 147-64 = 179-0 = 188-0 = 250-0 = 346-0 = 480-0 = 589-0 = 707-0 Weight of socket equals '9 foot of pipe. Weight of socket turned and bored and thickened spigot equal to 1*1 feet of pipe. Weight of flange equals 1 foot of pipe. Depth of Socket. Jointing Space. 2 inches and 3 inches diameter 3 inches f inch 4 to 8 4 9 20 ., 4* - 21 30 ., 5 Above , 6 LAYING MAINS. 291 To Test Mains in District. The portion of main to be tested must be isolated by bagging or water-logging, and a pressure put upon it by a motive power meter or small holder. The quantity of gas or air required to keep up the initial pressure equals the loss through leakage. Coating for Pipes. A composition of Burgundy pitch, oil, resin, and gas tar is made up in a bath, into which the pipes are lowered, where they remain until they attain the heat of this composition, which is about 142 F. They are then taken out and placed in such a position as to allow all unnecessary matter to run off. To find the force tending to dive off a bend on a line of pipes sub- jected to internal pressure. The resultant force in the straight pipe on either side of the bend being equal to the area, A, of the pipe, X the intensity,^?, of the pressure, and acting axially. The resultant of these two forces is A X p X 2 sin. _. where is the angle subtended by the bend. Pipes up to 9 inches diameter should never have less than 1 foot 9 inches of ground above them ; above this size the depth should be increased at least 6 inches. Pipes laid in clinkers and ashes will, after a time, part with a con- siderable portion of their iron, leaving a substance which can be easily scraped with a penknife. Clay, however, forms a most excel- lent soil for pipe laying. It has been noticed that gas pipes are attacked at points where electricity leaves them when in proximity to electric tramways, and not where the current penetrates them. Pipes with rough interior surface have been known to reduce delivery of liquids 33 per cent, from that delivered when smooth. (Fitzgerald.) Never drill a larger hole than | inch in a 2-inch main. Never drill a larger hole than 1 inch in a 3-inch main. In small mains a f-inch bend may be fixed to a reducing socket and a 1-inch service carried from that without materially reducing the quantity of gas which may be passed, and at the same time this method renders a small main less liable to leak. Allow a fall of 3 inches per 100 yards in street mains ; or better, mains should have a fall of about 1 inch in 20 yards as a minimum. Lay mains with a fall of not less than | to 1 inch to every 9 feet length. Where pipes have to be carried across exposed positions, as when they are slung or fixed outside bridges, &c., they should be covered with felt or other non-conducting material. Sleepers may be used with advantage under mains when laying in bad and soft ground. The ground should be well consolidated under mains to prevent subsequent uneven settlement. U2 292 GAS ENGINEER'S POCKET-BOOK. To find a leak try with a pricking bar near each socket, and to the full depth of the bottom of the main ; and if gas be present, even in a very small quantity, it will burn with a more or less blue light. A broken pipe may be temporarily bandaged with stout calico well plastered with white and red lead, until a new pipe can be laid. When lead pipes are used for services they must be supported their entire length, to prevent sagging and subsequent accumulation of water and stoppage of supply. Service pipes may be made to last longer by receiving one or two coats of good oxide paint or hot.tar. It is better to use soap and water (soft soap is best) than to employ a light to try if a joint in a main be tight or no. Millboard joints should be well soaked in water and painted both sides with red and white lead. Gas valves should stand 5 Ibs. pressure on side opposite springs. One or more trunk mains should always come from the works and terminate at central points, whence the distributing pipes may start. A piece of tallow in the " gate " of the joint when running with lead prevents blowing even if the yarn or pipe be wet. If too much lead is left on the outside of a joint the caulking up may split the socket. The yarn should not occupy more than half the depth of the socket when driven hard in with the tool. Ordinary putty may be used instead of lead for temporary joints after the yarn is well rammed in. It is the return currents of electricity which are responsible for the electrolytic action ; and it seems to have the same effect on galvanised, tar coated, or so-called " rustless " pipes. Cement for the Repair of Leaks in Gas and Other Pipes. To 5 parts of Paris white add 5 parts of yellow ochre, 10 parts of litharge, 5 parts of red lead, and 4 parts of black oxide of manganese. The constituents should be well mixed and a small quantity of asbestos arid boiled oil added. The cement hardens in from two to five hours after application to the leaks, and exposes no fresh holes on drying. As the use of the cement does not involve the removal of the *pip es it is especially adapted for the repair of those which are difficult to get at. In South Boston, U.S.A., all mains are laid with cement joints, made by using two hard-twisted rolls of lath-yarn, and a mixture of 2 parts of common cement, one part Portland cement, and one part sand. Turned and bored pipes are cheaper to lay, but do not allow of any settlement, and consequently break easier than the open lead joint. Leakage in cubic feet per hour through holes in plates *J pressure in inches X diameter of hole in inches 3 X 1200. (F. S. Cripps.) RACK AND PINION GAS VALVES. 293 Dimensions of Rack and Pinion Gas Valves. Diameter of Valve. Diameter of Flanges. Diameter of Circle through centre of Bolt Holes. Length from face to face of Flanges. Number of Bolts. Diameter of Bolt Holes. Inches. Inches. Inches. Inches. Inches. Inches. 2 6^ 5 i 8i 4 | 3 8 4 a 4 10 8 2 111 4 | 5 10J 9 Hi 4 1 6 12 10 HI 4 | 7 14^ 12 llf 6 8 15i 13 6 9 17 Mi 13i 6 10 18 16J 13| 6 12 20J 17 16 6 i 14 22 19 16i 6 j. 15 23 20 17 6 1| 16 24i 21 18 6 H 18 26^ 23 18 6 H 20 29 25 20 8 If 21 30 26^ 20 8 H 22 31 27 20 8 24 33 29J 20 8 1* 26 35 32i 20 8 27 36 32 20 8 11 30 39 35| 22 10 1* 36 46 42J 23 12 H 48 58 54J ^ 31 16 H Notes on Dr. Pole's Formula by F. S. Cripps. Let Q = the discharge of gas in cubic feet per hour. d = the diameter of pipe in inches. p = pressure of gas in inches of water. s = specific gravity of gas, air being 1. I length of pipe in yards. Then Q = 294 GAS ENGINEER'S POCKET BOOK. (1 350) 2 d*p _ From the above it is apparent that, other things being equal Q varies directly as ii inversely,, inversely d varies directly p varies directly as Q2 I varies directly p n inversely inversely , s varies directly as p inversely Q 2 A consideration, of the foregoing gives rise to the following axioms or rules ; Quantity Pres sure. (1) Double the quantity requires four times the pressure. Or, four times the pressure will pass double the quantity. (2) Half the quantity requires one-fourth the pressure. Or, one-fourth the pressure is sufficient for half the quantity. Quantity Length. (3) Double the quantity can be discharged through one-fourth the length. Or, one-fourth the length will allow of double the discharge. (4) Half the quantity can be discharged through four times the length. Or, four times the length reduces the discharge one-half. Quantity Diameter. (5) 32 times the quantity requires a pipe four times the diameter. Or, a pipe four times the diameter will pass 32 times as much gas. (6) A pipe one-fourth the diameter will pass l-32nd of the quantity. Or, l-32nd of the quantity can be passed by a pipe one-fourth the diameter. Quantity Specific Gravity. (7) The specific gravity stands in just the same relation to the volume as the length does (see Axioms 3 and 4). Pressure Length. (8) If the pressure is doubled the length may be doubled. And, conversely, if the length be doubled the pressure must be doubled. CRTPPS ON POLE'S FORMULA. 295 (9) If the pressure be halved the length may be halved. And, conversely, if the length be halved the pressure must be halved. From Axioms 8 and 9 it is evident that (10) The pressure required to pass a given quantity of gas varies exactly as the length of the pipe. Pressure Specific Gravity. (11) The pressure required to pass a given quantity or gas also varies exactly as the specific gravity of the gas. Hence if. the specific gravity of the gas were doubled, double the pressure would be required. Pressure Diameter. (12) l-32nd part of the pressure is sufficient if the diameter be doubled ; or, in other words, if you double the diameter you only require l-32nd of the pressure to pass the same quantity of gas. (13) If you halve the diameter, 32 times the pressure is required. And, conversely, if you increase the pressure 32 times, the diameter can be halved. Length Diameter. (14) The length can be increased 32 times if the diameter be doubled. And, conversely, if the diameter is doubled, the length can be increased 32 times and pass the same quantity of gas. (15) If the diameter be halved the length must be reduced to l-32nd to pass the same quantity of gas. And, conversely, if the length be made l-32nd of the distance, the diameter may be halved. Specific Gravity Length. (16) If the specific gravity be doubled, the length must be halved, and vice versa, to satisfy the equation. Specific Gravity Diameter. (17) The specific gravity follows the same laws as the length does in relation to the diameter. It must be borne in mind, when using the above rules, that all other conditions remain the same when considering the effect of one factor on another in the different pairs. (From the "Journal of Gas Lighting.") 296 GAS ENGINEER'S POCKET-BOOK. Service Pipes. If the distance from the main does not exceed 30 yards 1 to 10 lights require f inch wrought iron tube. 11 30 1 31 60 1 61 120 li 120 200 2 Allowing for partial closing of the pipes through corrosion ; | inch and smaller wrought iron tube should not be used. Lead, copper, compo. and brass tubes are measured by outside diameter ; iron pipes are measured by internal diameter. Cast iron pipes should be laid with a fall of J inch per pipe for outdoor mains, with ground well packed under joints before filling in, and not less than 21 inches from surface of ground. Service Pipes. (Shaw.) Greatest Number of Internal Diameter Burners allowed, of Pipe. at 5 Cubic Feet per Hour. Inches. | 10 25 45 Length of pipe, say, more than 100 feet. not 4 2 70 100 185 Length of pipe, say, more than 200 feet. not Services should be connected to gas mains by bend and hole in top of main. Half inch diameter services should only be used for public lamps. All services in doubtful soil should be thoroughly protected. Use hot pitch or a mixture of sand and tar in wooden troughs to prevent corrosion of service pipes. WROUGHT-IRON TUBES. 297 Average Weight of Butt-welded Gas Tubes and Fittings. Tubes Oength = 14ft.) Fittings. Bore. Weight per 100 Feet Run. Length re- quired to weigh 1 Ton. Weight of 10 Elbows. Weight of 10 Tees. Weight of 10 Crosses. Inches. Lbs. Feet. Lbs. Ozs. Lbs. Ozs. Lbs. Ozs. i 26-3 8,502 1 1 1 1 8 40-5 5,532 1 7 1 8 1 14 | 57-5 3.892 1 13 2 4 2 3 I 82-9 2,700 2 15 3 3 4 122-0 1,836 4 6 5 4 5 11 i 4 174-9 1,281 6 4 7 10 9 2 if 244-3 917 10 10 12 15 14 11 if 310-2 722 15 8 16 7 18 10 i* 359-5 623 15 12 20 21 4 2 421-0 532 22 6 27 31 4 2* 515-0 435 30 2 32 8 41 4 2 610-4 367 46 2 50 15 51 4 2| 658-8 340 55 10 68 8 80 10 3 759-3 295 73 8 85 5 88 12 3 878-4 255 101 121 129 4 1,032-3 217 126 144 158 Gas tubes are usually tested to 50 Ibs. per square inch. Water tubes to 300 Ibs., and steam tubes to 500 Ibs. Weight of 1,000 Feet of Gas Tube, Ordinary Quality. iinch = Cwts. Qrs. Lbs. i M 2 3 5 7 10 16 22 2 2 1 3 2 2 18 18 2 H i Q( If 2 2-! 2f 3 Cwts. Qrs. Lbs. 26 35 40 47 59 74 82 4 16 26 26 Table Showing Weight per Foot of Wrought Iron Tubing. Internal Diameter. GAS. WATER. STEAM. Weight per Foot. Weight per Foot. Weight per Foot. Inches. 1* H ii 2 2i Lbs. 1 1 2 3 4 5 Ozs. 14* H 15 10 2* i 101 Lbs. 1 2 2 3 4 6 Ozs. 15 7* 14 9 14 4 Lbs. 1 2 3 4 5 7 Ozs. 15* 8 Si 8 298 GAS ENGINEER'S POCKET-BOOK. Whitworth Threads for Gas and Water Pipes. Internal Diameter of Pipe. External Diameter of Pipe. Diameter at Bottom ot Thread. No. of Threads per Inch. Internal Diameter of Pipe. External Diameter ot Pipe. Diameter at Bottom of Thread. No. of Threads per Inch. Inches. Inches. Inches. Inches. Inches. Inches. i 3825 3367 28 li 2-245 2-1285 11 i 518 4506 19 2 2-347 2-2305 11 1 6563 589 19 2| 2-467 2-351 11 * 8257 7342 14 2* 2-5875 2-471 11 9022 8107 14 2| 2-794 2-678 11 f 1-041 9495 14 2* 3-0013 2-882 11 1 189 1-0975 14 2 3-124 3-009 11 1 309 1-1925 11 2| 3-247 3-1305 11 !i 492 1-3755 11 *| 3-367 3-251 11 H 65 1 -5335 11 3 3-485 3-3685 11 if 745 1-6285 11 3| 3-6985 3-5815 11 y 8825 1-705 11 H 3-912 3-7955 11 H 2-022 1-965 11 3! 4-1255 4-0085 11 if 2-16 2-042 11 4 4-340 4-223 11 Chart for Public Lighting. (Horstman.) Showing Lighting and Extinguishing Times for 3,650 hours' light per annum. J:: :::::::::;: ^ (^ 4*.,^ ' _ / \ / ^ / tfOJ8- V L ^ -, -t ,Z..:^t:. :::::::::/.: \ I ;*> . _ .\M- I , & I f ^ I Sin^iss:::::::!::::":::: > * ^ 7 ' / ^ / ;^::::::::$::::r::::~~ JAN. fB. \MA / APR. MAY JUNE 650M T Ml 114 II ittl li l|>yi fifKttC r)IOt7* IQI7M *, \ 7 joi. uc. stf./ OCT NOV. Kt 8 U2219 S ll Hit ( MpM 7 M t> 7(4 l| I3M I6ZS X W >. I . * \ I 7 ^ I. - 15 i ,,. IT :s / r- a:::5:::::::::;: 2 7 W /-. ^ \ *;oei> /* ^ go6. /_ Z \ " V " ^)04J, y >| ^ ^ \ blU . H - _ ^g- . ^ / V y ^ J s COMPARATIVE PRESSURES. 299 Comparison of Pressures in Inches of Mercury, Feet of "Water, and Pounds per Square Inch. 234567 8 9 10 IT Pounds per Square Inch. 12 13 14 IS 300 GAS ENGINEER'S POCKET-BOOK. 30 Ibs. pressure per square inch equals about a head of 70 feet, with a velocity of 66 feet per second. Therefore, area of pipe x feet per second equals discharge per second. Double pressure equals 1 times delivery. Four times length of main equals delivery. Double the pressure on the district increases the leakage about 50 per cent. Other authorities say loss by leakage is in direct proportion to the pressure. Mr. Hill found at Wallasey a loss of 1-7 per cent, between the station meter and the gasholder outlet due to temperature, and as the " Sales of Gas Act " allows 2 per cent, fast, and 3 per cent, slow, in the meters, he suggests that per cent, should be allowed off leakage on this account. With regard to district pressures it may be laid down as a safe rule that the lower the pressure can be kept, consistent with an efficient and proper supply, the lower will be the unaccounted-for gas. Gas at the depth to which the mains are laid, say 2 feet as the average, the temperature would be between 1 and 2 higher than that of the air. According to the Meteorological Office the mean air temperature for the United Kingdom may be taken as 48'69 F., so that 50 F. may be taken to be the average temperature of the street-mains at a depth of two feet. The mean rise of temperature between the main and the meter is 6 ; some meters show more and some less. (Lewis T. Wright.) Transmission of Gas of 0-55 Specific Gravity through Pipes and Bends (90). (Nelson W: Perry.) Inches Pres- sure. Cubic Feet. Delivered. Velocity of Flow in Feet per Second. Increase of Pressure per Bend. Total Increased Pressure for 25 Bends. Total Initial Pressure. 1 12,500 4-0 0-001 6 in. O'Oi ill. 1-04 2 18.000 6-0 0034 , 0-085 2-085 3 23,000 8-0 0-00<> , 0-1495 3-15 4 25,500 8-8 0-007I) , u-189 4-189 5 28,000 9-6 0-0081) . 0-215 5-215 6 32,000 11-0 0-0113 . 0-28 6-28 7 34,000 12-0 0-0135 . U-34 7-34 8 36,000 12-5 0-0147 , 0-39 8-39 9 38,500 13-0 0-0158 , 0-4 9-4 10 40,000 14-0 0-0183 , 0-46 10-46 Maximum pressure should not exceed twenty-tenths on district where possible. 1 to 2 inches pressure at works may be sufficient if the distributing mains are of sufficient capacity, and the district fairly level. NAPTHALENE. 301 Gas, after travelling ten miles, has been found to lose only about the coal by railroad, and generate hp e coa , electricity on the spot, than to generate it and transmit the current t WiO^ordlnary town gas of 16 candle power, 3,000 H.P. can be sent one mile for an expenditure of 1 H.P. = & per cent, of the power conveyed. Mr. Wright estimates the true loss as about 65 per cent, ot the unaccounted-for gas ; later, by another method, at 75 per cent. ; and now, from such examinations of the results of the inferential as he has been able to make (from the observation of the amount of water absorbed by the gas passing through consumers' wet meters), it appears to him safe to say that the bulk of the unaccounted-for gas is actual loss from the distributing system, always, of course, assuming the meter registration to be reasonably correct. Napthalene arises from the H of the gas passing through the main, by the action of the exosmose, and thus the carbon, deprived of its diluent, is deposited in its solid state. (Dr. Frankland.) If this were the case napthalene would always be deposited, which is not the case. Napthalene is found wherever there is a condensation of the aqueous vapour contained in the gas. If the aqueous vapour is removed from the gas, napthalene is not deposited under ordinary conditions of temperature and pressure. (Bremond.) Napthalene is generally only found when mains or services are laid less than 1 foot from the surface of the ground. Every deposit of napthalene equals a reduction of illuminating power in the gas. Naptha dissolves napthalene. No napthalene found in mains since water gas used at Blackburn. Napthalene is not likely to be found in mains if the gas contains more than 2 per cent, benzol. (Col. Sadler.) Of all enrichers, benzene, for the average consumer of gas, gives the greatest value for the money. Toluene and xylcne are better enrichers ; but their non-volatility precludes their employment. One gallon of benzol enriches 9,500 feet 1 candle, and 1 gallon of carburine will improve 2,800 cubic feet to the same extent (Mr. Hunt.) The temperature at which benzol volatilizes is a convenient one, as ordinary steam heat is all that is required. The amount of benzol vapour which common coal gas can per- manently retain, viz., over 50 grains per cubic foot at C., is greater by far than anything required to enrich low-quality gas to any reasonable extent. Benzol at a temperature of 70 to 80 C. will dissolve 2 to 2| Ibs. of sulphur per gallon, but when cooled to 25 C. it will only retain Ib. per gallon. Between 7 and 9 grains of benzol vapour will improve 1 cubic foot of gas between 4 and 5 candles. (Dr. Bunte.) 302 GAS ENGINEER'S POCKET-BOOKO The results of disillumined gas plus benzene are 0-0221 gramme per litre gives 1-3 candles 0-0385 , 4-1 0-0544 0-0630 0-0863 0-0881 0-1231 7-6 9-6 21-0 20-2 30-0 (Irwin.) Benzene gives about -4 candles per gallon per 1,000 cubic feet. Gas enriched 1 Candle by 1 Gallon of the Liquid. Benzol (chemically pure) .... 13,300 cubic feet. Benzol (90) 12,500 Carburine (680 specific gravity) . . . 5,700 Common petroleum spirit (700 specific gravity) 4,300 In an enricher a carbon atom combined with H 4 or H 3 is useless ; a carbon atom combined with H 2 possesses enriching power ; a carbon atom combined with H x possesses two or three times the enriching power of the foregoing ; and a carbon atom combined only with other carbon atoms again possesses two or three times the enriching power of a carbon atom combined with H. (W. Irwin.) By admitting alcohol vapour, in regulated amount, to the gas main, the illuminating power of the gas is unaffected thereby, though the freezing-up of the services is prevented. The alcohol is vaporized by steam or direct heating just before admission to the main, and the quantity is regulated according to the amount of gas passing per hour and the prevailing degree of cold. (Dr. J. Buel.) Disillumined Gas and Heptane (prepared by Fractionating Petroleum Spirit). 0-0528 gramme per litre gives 2-15 candles. 0-1010 ' 6-35 0-1516 11-10 Napthalene is the cheapest and greatest enricher, but it cannot be supplied with gas from the gas-works because of its non-volatility. It could, however, be used for the street lamps with a carburetting apparatus, which would give 50 per cent, more light for a mere fraction. Were separate mains employed and water gas used in con- nection with napthalene, the cost of street lighting would be reduced to a minimum. (W. Irwin.) In napthalene not more than 44 per cent, of the weight added to the gas is really utilized in emitting light. The napthalene in the gas in street mains may be held in suspen- sion, by admitting gasolene into the main outlet pipe leading from the works to the street main system, by reason of its greater affinity for it than moisture has. Napthalene melts at 174 F. and boils at 428 F, NUMBKli OF FEET FOR ONE PENNY. 303 8-S5- 8 8 g j; !*** I * =3 - J ^ Illll 8 4*S- 8 8P-S HUMBEIt Of CUBIC FftT fOH ONt PtNMY 304 GAS ENGINEER'S POCKET BOOK. Comparison of Prices of Gas in Sterling and French Monies. Price per 1,000 Cubic Feet. i2/- i3/- i4/- i5/- i6/- i7/- i8/- ig/- 20/- 2i/- 22/- 23/- 90 2/- 3/~ 4/~ S/~ 61- 7 1- 8/- g/- io/- xi/- Price per 1,000 Cubic Feet in Shillings and Pence. RELATIVE VALUES OF ILLUMINATING AGENTS. 305 Oxygen required for Complete Combustion. volume Methane requires . . . 2'0 volumes Oxygen. Hydrogen . . 0'5 Benzol . . . 7'5 Propylene . . 4-5 Ethylene . . 3-0 Carbon monoxide 0-5 (M. Casaubon.) Relative Values of Illuminating Agents. (Dr. Letheby.) In respect to their vitiating and heating effects on the atmosphere, when burning so as to give the light of 12 standard sperm candles. Thermal Units of Heat. Oxygen Consumed. Carbonic Acid Produced. Air Vitiated. Cubic Feet. Cubic Feet. Cubic Feet. Cannel Gas 1-950 3-30 2-01 50-2 Common Gas . . 2-786 5-45 3-21 80-2 Sperm Oil 2-325 4-75 3-33 83-3 Benzol . . . 2-326 4-46 3-54 88-5 Paraffin . 3-619 6-81 4-50 112-5 Camphine . . . 3-251 6-65 4-77 119-2 Sperm Candles 3-517 7-57 5-27 131-7 Wax . . 3-831 8-41 5-90 149-5 Stearic 3-747 8-82 6-25 156-2 Tallow . . 5-034 12-06 8-73 218-3 Gas Consumed and Carbon Dioxide Produced per hour to Yield an Illumination of 48 Candles. (16-5 Candle Gas.) (Professor Lewes, June, 1893.) Illumination Value per Cubic Foot. Gas Consumed. C0 2 Produced. No. of Adults to Produce CO 2 Flat flame No. 6 . 2-5 19-2 10-1 16-8 > 1. 5 2-1 22-9 12-1 20-1 i> * 1-9 25-3 13-4 22-3 London Argand 3-3 15-0 7-9 13-1 Regenerative . u-o 4-8 2-5 4-1 Paraffin Lamps 13-5 22-5 Candles, sperm 19 '(52 32-7 G.E. 306 GAS ENGINEER'S POCKET-BOOK. Duty in Candles of Various Burners at 5 feet per Hour. (J. H. Cox, Junior.) Duty in Candles. Standard Argand 16 Public lamps, average 13.] Good batswing after 1 year's use, rather dirty 10 Good batswing after being cleaned . . . 13^ Iron batswing. corroded and old . . , . 7^ Iron fishtail, corroded and old . . . *H Iron batswing, corroded and old . . , . 6 Iron batswing, corroded and old 3| Wasteful Argand . 5 Peebles' 5 feet regulator burner . . . ,14^ Bray's No. 8 flat flame burner . . . . 14 Borrowdail's governor burner. . . . c 13| Sugg's Christiania burner 14 A good unregulated burner under unnecessary pressure 8 Same burner regulated 12 Number 1 Argand, at 5 cubic feet per hour . .16 Number 1 Argand turned down to 3 cubic feet . . 8 Wenham lamp ground glass shade, at 45 . . 22 Average of above 18 burners . . . 11 Other Illuminants under Best Conditions. (J. H. Cox, Junior.) In candles per Id, Electricity (incandescent), at %d. per hour per 8 candle lamp 3J Candles Palmatine candles 6 to 1 lb., at 10d. per pound, 9 inches long burning 1 inch per hour. Illuminating power corrected to 120 grains per hour, 1 standard candles . Oil Petroleum burnt under best conditions in a 20 candle duplex lamp (oil at 1*. per gallon) 9i Burners when lighted uso less gas than when fumed on and not lighted ; a No. 3 burner lighted consumes 3 cubic feet, unlightcd 3i cubic feet per hour. Effects of different pressures on a No. 4 union jet burner : Pressure in inches . . 0'5 1-0 1-5 2-0 2*5 3'0 Consumption, cubic feet 3'9 5-6 7-0 8'45 9'6 10 5 Unit efficiency, candles . 3-0 2-4 1-9 15 1-35 I'll VITIATION OP AIR. 307 Carbon and Hydrogen Escaping Unconsumed per 100 parts C., Completely Burned. (W. Thomson, 1890.) Carbon. Hydrogen. Petroleum lamp, not burning at the full . with flame turned full on 1-204 0-309 Argand gas flame 0-025 0-011 0-254 Bray burner, consuming 4 cubic feet pur hour 1-112 0-095 Welsbach burner 1-5 0-379 Marsh-Greenall's heating-stove burning 5-62 cubic feet per hour 1-26 0-3 5-74 .... 3-76 1-18 7-10 .... 9-74 1-21 Thos. Fletcher's heating stove : with 8 Bunsen burners . . . . 4-33 2-46 burning 6-81 cubic feet per hour . 6-63 2-0 with 20 Bunsen burners with asbestos and fire-clay back consuming 8'14 cubic feet per hour . . . . 13-89 1-17 Heating stove 20-0 Vitiates per Hour. Units of Heat Generated. Cubic Feet. An adult man .... 215 190 Each cubic foot of gas burned . 8'5 600 Each pound of oil burned . candles burned . 150 160 | 16,000 Daylight on a well exposed table equals 4'6 foot candles. Minimum required for reading without fatigue equals 1 candle at 1 foot. Minimum required for fluent reading equals 1*4 to 2-3 candles at 1 foot. Minimum required for street lighting equals 0'09 candles at 1 foot. (Cohn and Wybauw.) The light from the edge of a petroleum lamp flame equals 62 to 63 per cent, of that from the flat side. The reflective power of a whitewashed ceiling equals a loss of light of only 20 per cent, (H. E. Harrison.) The intensity of illumination on a given surface is inversely as the square of the distance from the source of light. X 2 GAS ENGINEER'S POCKET-BOOK. Adults inhale about 1 pint of air at each breath and take 18 to 20 breaths a minute. The heat evolved by a gas flame is the best of all ventilating mediums, provided a simple means is secured for conveying the products of combustion out of the room. It is said that the injury done to books by gaslights is not due to the sulphur in the ,as but by what is called carbon oxysulphide, condensing on any object a foot or so below the ceiling. If a chimney is properly constructed it may be used for a venti- lating flue, and be able to give a pull of one and half to two tenths of an inch vacuum, which is sufficient to convey away all the vitiated air from a room if the flue pipes are large enough. Temperature cf air in rooms should not be more than 10 higher at 1 foot from the ceiling than at 1 foot from the floor. Two- tenths of an inch draught gives a velocity of air of about 6 feet per second. Inflowing air should, if possible, be warmed to within 10 or 15 of the temperature of the room. The rarer the atmosphere the larger the flame ; the denser the atmosphere the smaller the flame. When coal gas is burnt sulphur is liberated as sulphur dioxide, but this is not further oxidized to sulphuric acid (H 2 S0 4 ) unless the tem- perature falls so greatly that water is deposited. " A certain amount of sulphurous acid is no doubt formed wherever gas is burnt, and this may, in the presence of moisture, be converted into sulphuric acid, but when ordinary ventilation is used, the amount must be very trifling. Dust collected in rooms where no gas is burnt is found to contain an equal quantity of sulphates as that found in gas-lighted rooms. No instance of imperfect combustion has been ever substantiated against lighting-burners, nor even against heating-burners of good class when employed under their normal working conditions. (L. T. Wright.) C0 2 in gas has more effect on a flat flame than in an Argand in reducing the light, the depreciation being less the higher the candle power. No trace of CO or acetylene was found in the products of combus- tion from Welsbach, Argand, and Bray burners. (Lancet.} Two cubic feet H + 1 cubic foot O forms 2 cubic feet aqueous vapour. By heating the air and gas before combustion, the carbon particles in the gas are liberated earlier and brought to a higher temperature, at the same time they are kept at this temperature for a longer period. The burner tip should be of a non-conducting nature, as steatite, so as not to reduce the intensity of combustion. In Argand burners the supply pipes to the ring are generally of smaller area than the sum of the areas of the holes in the latter so as to reduce the pressure at the point of consumption. Angle at which the mean intensity of flat flame burners is obtained varies from 1-5 *o 10'25, average 4-68. (A. C. Humphreys.) PROPER HEIGHT OP LAMPS. 309 Sizes of Internal Pipes, Lead and Iron, According to Number of Burners Required, as Allowed by Blackpool Corporation Gas Department. Internal Diameter of Pipe. Greatest Length Allowed. Greatest No. of Burners. Internal Diameter of Pipe. Greatest Length Allowed. Greatest No. of Burners. Inches. | I Feet. 20 30 40 50 3 6 12 20 Inches. 1 H H 2 Feet. 80 100 150 200 40 60 100 200 Light absorbed by clear glass globes engraved globes . ,, globe of ordinary pattern obscured all over white opal globe painted opal globe 12 percent. 24 35 40 60 64 , Clear glass prevents 10*57 of the light from passing through it, ground glass stops 29'48, smooth opal glass over 52'83, and ground opal more, 55'85. Formula for determining the height of lamps for a known radius of lighting h = I J 2~= 0-7 I The proper height of any light should be - 7 of the area to be lighted by any one light. (Electrical Committee Chicago Exhibition.) The proper height of any light should be such as to give an angle of 7 to the most distant point it is intended to serve. (Professor H. Robinson.) For comparisons of lighting he reduces the various distances, etc., to a co-efficient. Candle power of lamp X height of lamp in feet distance from lamp to farthest point served in feet 3 With Argand or flat flame burners free to the air, the distribution of light upon a circumscribing sphere of radius 1 is equal, but this is not the case with regenerative or incandescent burners. (W. Hy. Webber.) Table of Lighting. (Deduced from R. Richards.) Street lighting Church ',', Theatre " Public halls lighting Workshop . Road or pavement . Walls . General . Pew or reading desk Auditorium General area candle foot. 2 to 310 GAS ENGINEER'S POCKET-BOOK. Table of Lighting, (Deduced from R. Richards) continued. Workshop lighting Benches 3^ candle foot. . Optical or fine work . .5 Domestic Corridors, passages, halls, etc. f . Living rooms . . . . | ., Library, study, or bedroom . \ ., . Table lighting ... 2 The sun's light equals about 5,600 candles placed at a distance of 30 centimetres. The moon's light equals about ^th candle placed at a distance of 3 '65 metres. The sun's light equals 5,500 candles placed at a distance of 12 inches (another authority). Formula to Find the Intensity of Light any Distance. Initial power of the light Intensity =- F di6tancea Formula to find the Initial Intensity of any Light. Initial intensity = intensity found at any point X distance of that point from the source of light 2 . Formula to find distance at which any Intensity will be found. /Initial power of the light Distance = V - Intensity desired Formula to find Intensity of Light falling upon a point in a horizontal plane from a source above it. Illuminating power of source X vertical height above plane Slant distance 3 German Experiments show that a light of 1 candle power can be seen 1-4 mile on a clear dark night, and 1*0 mile on a rainy night. American Experiments show that in clear weather a light of 1 candle power is visible at . . .1 mile. 3 (with a binocular) 2 miles. 10 ,, ,, }> 20 (faintly) . . . 5 33 (easily) . . . 5 Dutch Experiments show that a light of 1 candle power is visible at 1 mile 3} ,, 2 miles 16 ; , ., 5 VENTILATION. 311 A green light to be seen at 1 mile at sea must be of 2 candle power. 2 miles 15 ** n "* i? *> 4 n ,. 106 ,, The shade of green recommended is a clear blue green ; the shade of red a coppery red. Ked lights show better than green ones at the same distance. One light of whatever intensity is not perceptible to our eyes in presence of a light 64 times brighter. (Bouguer.) The intensity of illumination which is received obliquely is pro- portional to the cosine of the angle which the luminous rays make with the normal to the illuminated surface. (Dr. Atkinson.) Freshly fallen snow reflects 78 per cent, of light. White paper 70 sandstone 24 Ordinary earth, road surfaces, etc. 8 Old Rule for Numbers of Burners Required for Effective Lighting- Floor area in square feet 50 Ventilation Notes. Ventilation should be arranged so as to change the air in a room in 10 minutes as a maximum. With a 6-inch vertical flue 12 feet long the most economical burner to use is one of 1 cubic foot per hour capacity, this will remove 2,460 cubic feet of air per hour. The maximum consumption of gas in a ventilating flue should not exceed 5 cubic feet per hour for each circular foot area of section. The atmospheric and illuminating flame is the same in all cases where a large quantity of air has to be heated to a low temperature. The consumption of 1 cubic foot of gas in a ventilating shaft can be made to remove more than 2,400 times its own bulk. Normal air contains 0'364 grains C0 2 per foot. Air to be pure should not contain more than 7 grains C0 2 per cubic foot. Adult expires 15 cubic feet of air per hour, containing 4J per cent. C0 2 = '8 cubic feet per hour. Air at 60 should not contain more than 5 grains moisture. l Adult. 1 Cubic Foot Gas. Cubic feet of C0 2 per hour given off by . 0-8 0-5 Heat units given off by . . . . 480 620 Grains per cubic foot of water vapour Cubic feet of air actually used by . . 200 15 440 60 ,, vitiated in an unventi- latcd room . 1,200 800 312 GAS ENGINEER'S POCKET-BOOK. Ventilation should be 2,000 to 3,000 cubic feet per hour. About 3 cubic feet to 4 cubic feet per minute of air is required for each adult. Sleeping apartments should have about 1,000 cubic feet per occupant. Workshops and living rooms not less than 600 cubic feet per person. For each lamp or gas burner from 30 to 60 cubic feet of air is required per hour. A 4 -inch shaft 8 feet long, with the help of a jet of gas burning to | of a cubic foot per hour, will aspirate upwards of 1,100 cubic feet of air per hour in a still atmosphere, and with further assistance of a wind moving across the ventilator at a velocity of 4 feet per second, it will aspirate 3,126 cubic feet per hour. A 6-inch similar cowl, with a burner consuming 4 cubic feet of gas per hour, will, in a still atmosphere, aspirate about 2,500 cubic feet of air per hour, and with the assistance of wind moving at the velocity of 9 feet per second it will aspirate 6,840 feet per hour. (W. Sugg.) Professor Smithells concludes that when compounds of carbon and hydrogen meet oxygen the C is first oxidised and the H liberated, which is then converted into steam by oxidation. The light of the flame being due to carbon formed by the decomposition of hydro- carbons by the heat of the primary combustion, according to the equation : 3 C 2 H 4 = 2 CH 4 + 4 CH + 2 H 2 . Professor Lewes believes that the H rapidly, and the methanes slowly, diffuse to the outside of the flame, and are burned, producing heat sufficient to raise the temperature of the gas to 1,000 C., at which temperature the unsaturated hydrocarbons and the higher saturated carbons and hydrogen compounds being decomposed into acetylene, the heat rising to 1,200 C. changes the acetylene into C and O, and the C becoming incandescent gives off the light. Gas-flames with an ample supply of primary air when in contact with incandescent surfaces, do not discharge combustible gases among the products of combustion. Professor Macadam found that with 4*85 candle power per foot gas, the best value with a Welsbach S burner was 10*66 candle power per foot, with 7*12 candle power per foot gas it was 12*75 candle power per foot, and with 2*80 candle power per foot gas it was 13*63 candle power per foot. The loss by different glasses, etc., is shown as follows : Clear glass 1 cubic foot = 12*81 candle power. Mica .... =12-81 Amber glass 1 cubic foot= 12*18 Kuby glass . . = 9*06 When gas gets much above 24 candle power, it is not advantageous to employ the ordinary form of Welsbach C burner as supplied by the company at the time (1895). (Professor W. I. Macadam.) By a more perfect admission of gas and air in a Bunsen burner, a corresponding heat development ensues, and a light equal to 27 candles per cubic foot can be obtained with 16 candle gas and without a chimney with the Welsbach- Deuayrouze burner. COMPARATIVE COST OF DIFFERENT LIGHTS. 313 Number of Candle-power Hours which can be Provided at the Same Cost. (Prof. D. E. Jones.) Wax .... Stearine . . . . Incandescent electric light Coal gas (slit burner) . Acetylene and air (slit burner). . . . Oil gas .... Water gas and benzene . 33 77 440 625 716 1.660 1^666 Electric arc . . . 2,322 Schulke's petroleum-gas lamp . ... 2,250 Auer - Welsbach burner with coal gas . . 2,300 Auer - Welsbach burner with water gas . . 4,350 Comparative Cost of Different Illuminants (Germany). Gas Argand burner ....... 943^. small Wenham burner ...... 483*2. carburetted with napthalene, No. 2 Bray burner 574,*) 1. It is desirable that the stove should afford radiant heat only. 2. For this purpose some form of clay " fuel " is best. 3. Attention should be given to the packing of the " fuel " so as to avoid undue clogging or impeding the flow of the flames. 4. The stove should be supplied with separate burners with taps. 5. Some means of controlling the supply should be adopted. Governors or regulators are indicated. 6. A simple arrangement appears to be necessary by which undue drying of the warmed air may be avoided. 7. Indestructible enamel, or enamel little affected by the heat, should be used for coating the stove ; common paint, varnish or ordinary enamel should be avoided. 8. An efficient flue should in all cases be provided with gas fires, however, the flue pipe may be much smaller than the chimney required by coal fires. 9. The burner should be as far as possible noiseless. Pressure for gas stoves should not be less than four-tenths, eight- tenths best. One volume of gas requires 5 volumes air for complete combustion. Average mixture of gas and air in gas stove Bunseu burners is! 1 to 2-3, remainder 3'2 is supplied around the flame. On a large scale one pound of meat can be cooked by 1 cubic foot. of gas. Gases in flues of gas stoves consist of about : Oxygen, 12 pc J cent. ; Nitrogen, 84 per cent. ; CO 2 4 per cent. 40 cubic feet of gas in an average gas stove raised the temperature of a room 1,080 cubic feet, 5 F. GAS STOVES. 315 Size of Pipes and Lengths Allowed for Gas Stoves by Blackpool Corporation Gas Department. Average Inside Size of Oven. Distance of Stove from Meter. Pipe Required. 11 inches X 11 inches X 14 inches under 30 feet % inch. 11 Xll X14 if 60 A 14 X14 X24 if 30 I 14 X14 X24 if 60 I 15i X 15 X 24 if 30 15i Xl5i X24 if 60 1 19 X 18 X24 if 30 1 19 X18 X24 if 60 ., H Connect all gas stoves with a large gas supply and with full-way taps and fittings. The chimney should be closed with a wrought iron plate with a hole in it to allow the flue of the gas stove to pass through. One degree F. rise in temperature per 15*4 cubic feet gas consumed. Seven Ibs. coal required for same rise in temperature. (Professor Lewes.) Total calorific value of gas is constant, whether Bunsen or luminous flames are used, if complete combustion is assured. The latter, however, must be kept sufficiently far from the object being heated so that the flame may not impinge upon its surface, or soot will be deposited, forming a non-heat-conducting layer, and so diminish the energy of the flame. As regards the calorific value of the gas Carburetted water gas 145 Coal gas . . . 136 Mixed gas . . . 136 per 4 2 cubic feet. The permanent gas from the flue of a gas stove consists wholly of C0 2 , N and 0. (Lancet) Warming by Steam. When the external temperature is 10 below freezing point, in order to maintain a temperature of 60 One square foot steam pipe for each 6 square feet glass in windows. One square foot steam pipe for every 6 cubic feet of air escaping for ventilation per minute. One square foot steam pipe for every 120 feet of wall, roof, or ceiling. One cubic foot of boiler is required for every 2,000 cubic feet of space to be heated. 316 GAS ENGINEER'S POCKET-BOOK. One horse-power boiler is sufficient for 50,000 cubic feet of space. Steam should be about 112. Heating. 1 square foot of pipe surface heated to 200 will cause an average of 58 of heat in 150 cubic feet of air. Heating Rooms. 1 square foot of pipe surface is required for 80 cubic feet of space ; 1 cubic foot of boiler is required for 1.500 cubic feet of space ; 1 horse-power boiler is sufficient for 40,000 cubic feet of space. Allow 1 square foot pipe surface per 120 feet wall and ceiling space for steam heating. Allow 1 cubic foot for every 1 ,300 square feet wall surface when once warmed, but for preliminary heating about four times this amount is required, which also allows for ventilation. The length of piping required to represent 1 square foot of heating surface 36 inches of 1 inch wrought iron tubing to 1 square foot. 28 24 20 16 13 10 1! 2 2i 3 4 cast iron The allowance would be 18 square feet of heating surface for living rooms, 13 feet for bedrooms, and 20 feet for halls for each 1,000 cubic feet of air in the place to be warmed. 1 inch main will supply up to 70 square feet. 1 inch main will supply up to 150 square feet. 1 inch main will supply up to 300 square feet. 2 inch main will supply up to 600 square feet. 2J inch main will supply up to 800 square feet. (Gr. Chasser.) Percentage of Heat Evolved by Open Grates and Close Stoves. (D. K. Clark.) Open Grates. Close Stoves. Heat carried up the chimney Radiated and conducted heat absorbed by the walls . -i ' '. .-' . . ' Heat lost by radiation and conduction externally, and heat lost by imper- fect combustion .... 43 per cent. 42 15 24 54 22 100 per cent. !) 100 One pound of coal burnt in an ordinary grate requires for its combustion 300 cubic feet of air having a temperature of 620 F. (Sir Douglas Galton.) HEATS OF FIRES. 317 Quantity of soot given off by a coal fire burning house coal of different qualities. The amount is said to be on the average 6 per cent, of the carbon in coal. Bunsen burners should be made on the same lines as injectors, as the rush of the gas at the nipple causes the intake of air at the side holes. The full -pressure of the gas should therefore be allowed to proceed to the nipple. To Prevent Stoves from Busting. Melt 3 parts lard with 1 part powdered resin ; add black lead if desired. Brush over in a thin coat. Best Heats for Cooking. Roasting pork Veal . Pastry . . puff 320 F. 320 320 340 Beef . Mutton . Meat pies 310 F. 300 290 Heats of Different Fires. Heat of a common wood fire = 800 to 1,140 F. ., charcoal fire = 2,200 (about). coal fire = 2,400 Number of Grammes of Water Raised 1 through Equal Thickness of Plate. Copper Zinc Iron 918 292 156 Tin Steel Lead 150 from 111 to 62 . 79 Breeze mixed with tar (40 gallons to the ton) does not produce a smoky fuel, and retains its shape. The pitch used for agglomerating briquettes must not have had its binding qualities destroyed by the removal of its anthracene and heavy oils. A suitable pitch should soften at 75 C., melt at 100 to 120 C., remain hard at the normal temperature, and be capable of carriage in bulk. Its fracture should be dead black, conchoidal, clean and soft, without being greasy to the touch ; and the edges should not splinter when bitten by the teeth. So prepared, coke would burn as freely as bituminous coal. (W. Colquhoun.) Tar for making pavements should be heated until converted to pitch that will harden on cooling. If overheated it loses its elas- ticity, and pavements made with it disintegrate rapidly. Refuse materials, such as clinkers, may be employed, and the pitch should be run straight from the boiler on to them, well mixed and laid and rolled at once. One barrel of boiled tar will make 50 cubic feet of pavement. 318 GAS ENGINEER'S POCKET-BOOK. Proportions of Tar Concrete. Aggregate .... Sharp sand (clean) Coal tar .... Lias lime or Portland cement 7 parts. 2 6 2 . For the manufacture of tar paving it is usual to heat the stones over an iron plate, and then add tar which has been heated in open boilers, and the lighter oils evaporated at about 1 94 F. The time taken for this heating varies from four to twelve hours, as it is not desirable that the creosote oils should be distilled off. Briquettes. Good coal briquettes contain 5 per cent, of pitch if strongly pressed, or 7 to 8 per cent, if pressed with inferior or hard pitch. Balloons. The lifting power of a balloon is the difference between its weight and that of the air which it displaces. 1 cubic foot air weighs approximately -075 Ib. or 1-29 ozs. 1 hydrogen -005 -089 1 coal gas -043 -35 1 air heated to 200 C. weighs approximately -042 Ibs. Therefore lifting power of coal gas = '075 - -043 = -032 Ib. for each cubic foot contained in the balloon. The lifting power of hydrogen equals GO to 70 Ibs. per 1,000 cubic fest, that of coal gas being about 32 Ibs. Comparative Cost per Horse power per Hour. (Herr C. Korte.) Size of Motor (horse-power). | i I 1 2 3 d. 4 d. 6 Class of Motor. Hours daily. d. d. d. d. d. Gas motor (gas at 3s. 4d. j 5 7-92 5-76 3-72 2-88 2-52 2-40 2-28 per 1,000 cubic feet) . 1 Hydraulic motor (water at ) 6M. per 1,000 gallon sH 90 Ibs j 10 5 10 5-76 12-12 10-56 4-08 10-80 9-84 2-64 9-72 9-12 2-88 9-00 8-64 2-04 1-92 1-80 Electric motor (Berlin J 5 8-88 7-22 5-88 5-04 4-68 tariff) . . . .1 10 7-56 6-48 5-40 4-80 4-44 Compressed air motor J 5 15-00 11-64 8-40 6-96 6-00 5-40 4'32 (Paris tariff) . . . 1 10 13-08 10-44 7-68 6-48 5-84 5-16 4-08 Steam motor, with coal at f 5 4-20 2-88 2-40 2-04 i-so 12s. 6d. per ton .1 10 2-88 2-04 1-68 1-44 1-32 Steam motor, with coal at j 5 4-92 3-48 3-00 2-82 2-28 20s. per ton . . . 1 10 3-48 2-52 2-16 1-92 1-G8 Hot air motor, with coal at f 5 11-28 6-72 4-44 3-36 12s. 6d. per ton ( 10 6-48 4-08 2'76 2-16 ~ ~ WET METERS. 319 Extract from Hartley's "Analysis of Gas." A wet meter becomes slow to a certain limited degree in registration when worked above, arid fast to a lesser degree when worked below its proper speed, as will be seen from the following results of careful experiments : Meter working at 2.\ times its proper speed . rO2 per cent. slow. ,, its proper speed . . . correct. i of its proper speed . . '28 per cent. fast, i -c jft it >> To " It is therefore manifest that the surest way to attain accuracy will be to always work the test meter at its proper speed, and only use it with meters as liii'ge, or larger than itself. The closer the relation is in capacity between the test meter and the one under test, the more accurate will be the results ; as a rule, the former meter should not be less (or, at all events, much less) than one-tenth of the capacity of the latter. In testing large meters at one-fifteenth or one-twentieth of their speed, I have found it necessary to increase the allowance at times to as much as 1 and 1} .per cent. No definite rule can be laid down, however, because the extent of disturbance of the water level in the measuring wheel depends partly upon the relative areas of the wheel and meter case, and these vary with almost every meter. It may, however, be safely assumed that if a station meter, to which kind the application of a test meter should be generally restricted, registers 2 per cent, fast at one-tenth of its speed, it will be correct within the meaning of the act at full speed. The best plan would of course be to keep them within closer limits. Use a constant water level gauge in station meters, and keep a con- tinuous stream of water running in. A groaning station meter may be quieted by pumping in below the water line a hot water solution of soft soap and oil. Wet Meters. Lights. Capacity of Drum. Cubic Feet. Capacity per Hour. Cubic Feet. Diameter of Inlet. Dimensions over all. Back Height. Width. to Front. Inches. Inches. Inches. Inches. 2 083 12 15$ X 10 X 7 3 125 18 17 X 12i X 8f 5 25 30 | 18| X 15i x g| 10 5 60 1 21i X 19i X 121 15 75 90 1 24 X 2l| X 14$ 20 1 120 H 26| x 23| X 15 30 1-5 180 H 28| X 26* X 17| 50 2-5 300 28| X 26f X 22 60 3 360 H 28f X 26J X 25 80 4 480 2 33f X 30J X 28| 100 5 600 2 38$ X 35* X 29$ 150 7-5 900 3 40 X 39 X 31f 200 10 1,200 3 43| X 42 X 32 250 12-5 1,500 \ 46 X 45$ X 32f 300 15 1,800 ill 46 X 45$ X 45| 400 20 2,400 Q 49| X 48| X 48 500 25 3,000 51^ X 50^ X 62 600 30 3,600 / H 51^ X 50J X 65i 320 GAS ENGINEER'S POCKET-BOOK. Dry Meters. Lights. Mameter of Inlet. Capacity per Revolution. Capacity per Hour. Dimensions over all. Back Height. Width. to Front. Inches. Cubic Feet. Inches. Inches. Inches. 2 | 083 12 HI X 101 x 71 3 | 125 18 15* X Hi X 8 5 16 30 17 X 13 X 8| 10 I 4 3 60 19i X 15 X 10 15 1 416 90 21i X 16 X 11|- 20 H 5 120 24 X 18i X 12 30 if 83 180 25| X 20| X 14 40 if 1-25 240 29f X 23 X 17 50 if 1-428 300 32i x 251 X 21 60 if 1-6 360 33i X 27^ x 21 80 2 2-5 480 38J X 31i x 22 100 2 2-857 600 40| X 32i x 23i 120 *i 3-3 720 46i x 35* X 26 150 3 5-0 900 48 X 38 X 27 200 3i -g 6-6 1,200 56f X 42i x 29 250 3* i 7-3 1,500 56 X 45 X 32i 300 4 g 8-3 1,800 62 X 48 X 37 400 4 12-5 2,400 70 X 52 X 40 500 5 s 14-285 3,000 73| X 58 X 46 600 6 "v 22-222 3,600 77 X 58 X 50 800 7 J 25-0 4,800 88 X 61 X 52 1000 8 C 33-333 6,000 90 X 64 X 54 Standard Sizes of Unions for Connecting Gas Meters. (Board of Trade Standards Department, 1902.) Size of Meter No. of Lights. Diameter of Outside Thread of Boss. No. of Threads per inch. Diameter of Boss Opening to Admit Short Shank of Lining. Depth of Thread. Inches. Inches. Inches. 2&3 0-98 18 0-6(i 0-36 5 1-15 12 0-82 0-55 10 1-45 11 1-05 0-57 20 1-82 11 1-40 0-57 30 2-05 11 1-55 0-57 50 2-25 11 1-75 o-r>7 60 2-45 ' 11 2-00 0-57 80 & 100 3-02 11 2-30 0-57 PREVENTING METERS FREEZING. 321 Meters. Theoretical capacity of meters to pass gas is 6 feet per hour per light, though in practice larger quantities can be passed. All meters should be fixed perfectly level. The meter which is correct at a low pressure would be found to be Slow at a high pressure. In America the average tests of dry meters in one town was per cent, slow, and in another town | per cent. slow. Dry meters are liable to absorb the illuminants of the gas on the leathers which are always oily. Even the water in the photometer meter may have a thin stratum of oil on the surface which will some- times absorb the illuminants, and it ought, therefore, to be washed out occasionally, and filled only with distilled water having about 2 per cent, of pure, glycerine in it. To prevent wet meters from freezing, pack horse manure round them, or Turn off main cock and light a jet in house to consume the pressure in the pipes, unscrew plug and pour in, say, two table-spoonfuls of glycerine (for a three-light meter), allow a few minutes for the glycerine to come to the surface, and then shut off cock in house and turn main cock on again. 10 per cent, glycerine freezes at 30 F., 20 per cent, at 271 F., 30 per cent, at 21 F., 40 per cent, at F. (Veitch Wilson.) Glycerine is said to have the effect of reducing the illuminating power of the gas when used with water in a gas meter. Mixture used in E.A. Hydraulic Jacks to Prevent Freezing. Methylated spirits 7 gallons. /\ Area " Diamr ' Distilled water . 3 /-.A 7-854 - -3165 Mineral oil . . i , Carbonate of soda 250 grains. /. \ 15-708 = '447 A governor cone should be heavy enough to prevent oscillation, and a parabolic curve of a length equals twice the diameter (see drawing). To force gas down, say a mine, a jet of water may be sprayed into the top of pipe, and will cause an injector action according to the quan- tity of water in use. Area of governor bell some- times taken at 20 times area of base of cone. \ 23-502 548 ....31-416 = '6325 . 39-77 712 ... 47-624 = -779 54-978= -837 ...62-832 = '895 70-686 = -9485 ...78-54 --1-0 G.B. 322 GAS ENGINEER'S POCKET-BOOK. TESTING, Elementary Bodies, Symbols. Combining Weights. Specific Gravity. Melting Points. C. Aluminium Al 27-0 2-67 Antimony . . Sb 120-0 6-71 425 Arsenic As 74-9 f 5-67 j 5-9 Barium . . Ba 136-8 4-0 Beryllium . . Be 9-2 Bismuth . . Bi 208-0 9-8 270 Boron B 11-0 2-69 Bromine . . Br 79-75 2-966 Cadmium . Cd 111-9 8-65 315 Caesium . . Cs 133-0 Calcium . Ca 39-9 1-58 Carbon . . . C 11-97 Cerium Ce 139-9 Chlorine . . Cl 35-37 Chromium Cr 52-1 7-3 Cobalt . . . Co 58-6 f 7-81 \ 8-5 Copper Cu 63-1 8-93 1090 Didymium . . D 142-0 Erbium E 166-0 Fluorine . . F 19-1 Gallium . G 69-8 + 30 Gold . . . Au 196-2 19-3 Hydrogen . H 1-0 06926 Indium . . . In 113-4 7-42 Iodine . . I 126-53 4-95 Iridium . . Ir 192-7 22-38 Iron . . . Fe 55-9 7-8 1050 to 1600 Lanthanum . . La 138-0 Lead . . * Pb 206-4 11-35 334 Lithium ,... . Li 7-01 0-594 Magnesium Mg 24-3 1-74 Manganese Mn 55-0 8-01 Mercury . . Hg 199-8 13-59593 at C. - 40 Molybdenum Nickel . Mo Ni 95-8 58-6 8-8 Niobium . . Nb 94-0 Nitrogen . N 14-01 97137 Osmium . . Os 198-6 22-5 21-4 Oxygen O 15-96 1-10563 Palladium . . Pd 106-2 11-4 Phosphorus P 30-96 1-77 AIR, GAS, AND WATER, Elementary Bodies continued. 323 Symbols. Combining Weights. Specific Gravity. Melting Points. C. Platinum . . Pt 194-5 21-5 Potassium . K 39-04 0-865 62-5 Rhodium . . Kh 104-1 12-1 Rubidium . Rb 85-2 1-52 Ruthenium . . Ru 103-5 12-29 Scandium . Sc 44-0 Selenium . . Se 78-0 4-3 Silver Ag 107-66 10-5 1000 Silicon . . . Si 28-0 Sodium Na 22-99 0-974 95-60 Strontium . . Sr 87-2 2-54 Sulphur . S 31-98 2-00 Tantalum . . Ta 182-0 Tellurium . Te 125-0 6-25 Terbium . . Tb 148-5 Thallium . Tl 203-6 11-85 Thorium . . Th 231-5 Tin . Sn 117-8 7-29 235 Titanium . . Ti 48-0 Tungsten . W 184-0 Uranium . . U 240-0 18-4 Vanadium V 51-2 Ytterbium . . Yb 173-2 Yttrium . Y 89-0 Zinc . . . Zn 65-1 6-8 to 7-2 433 Zirconium . Zr 90-0 (In the case of gases, air = 1. , solids, water = 1.) Air, Gas and Water. Pressure of atmosphere = 14-7 Ibs. per square inch = 2116-8 Ibs. per square foot. Pressure of atmosphere equals 29-9 inches of mercury at sea level. 33-9 feet of water at sea level. 29 cubic feet of coal gas equals 1 Ib. approximately. 1 cubic foot of air at 62 F. equals -076 Ibs. Gas or air expands s ^ud of its bulk at 32 F. for each degree F. Water is at its maximum density at 39-2 F. (4" C.) and expands ith part of its bulk on freezing. Centre of pressure -jfrds depth from surface. 1 litre of fresh water =1 kilogramme = -001 cubic metre = '22 gallons = 2'2 Ibs. = '0353 cubic feet = 61 cubic inches. 1 ton of fresh water equals 1,016 kilogrammes, 1-0165 cubic metres, 1,016 litres. 1 ton of fresh water = 35'9 cubic feet = 224 gallons. 1 cubic metre of fresh water = 1,000 litres = 1,000 kilogrammes. 35-316 cubic feet = 220 gallons = 2,200 Ibs. 1 cubic foot of fresh water = 62-425 Ibs. = -557 cwts. = -028 tons. Y2 324 GAS ENGINEERS POCKET-BOOK. 1 cubic foot of fresh water equals 6-24 gallons, or salt water 64 Ibau 1 cubic inch of fresh water = '03612 lbs. = -003612 gallons. 1 gallon of fresh water = 10 Ibs. = '16 cubic feet. 1 cwt. of fresh water = T8 cubic feet= 11*2 gallons. Head of water in feet equals pressure in Ibs. per square inch X 2'30T, Pressure in Ibs. per square inch equals height in feet X '4335. Pressure of a Column of Water per Square Inch and per Square Foot in Lbs. Head. Pressure per Square Inch. Pressure per Square Foot. Head. Pressure per Square Inch. Pressure per Square Foot. Inches. Lbs. Lbs. Feet. Lbs. Lbs. m 260 25 10-82 1562-4 1 520 30 12-99 1874-9 1-041 35 15-16 2187-4 JL 1-562 40 17-32 2499-8 JL 2-083 45 19-49 2812-3 i_ 2-604 50 21-65 3124-8 tio 3-124 55 23-82 3437-3 3-645 60 25-99 3749-8 .8. 4-166 65 28-15 4062-2 JL 4-687 70 30-40 4374-7 I 10 0362 5-208 75 32-48 4687-2 2 0723 10-416 80 34-65 4999-7 3 1085 15-624 85 36-82 5312-2 4 1446 20-833 90 38-98 5624-6 5 1808 26-040 95 41-15 5937-1 6 217 31-248 100 43-31 6249-6 7 253 36-457 110 47-64 6874-6 8 289 41-666 120 51-98 7499-5 9 325 46-872 130 56-31 8124-5 10 362 52-08 140 60-64 8749-4 11 398 57-29 150 64-97 9374-4 12 434 62-5 200 86-63 13124 Feet. 250 108-29 16249 2 86 125-0 300 129-95 19374 3 1-30 187-5 350 151-61 22499 4 1-73 250-0 400 173-27 26248 5 2-16 312-5 450 194-92 29373 6 2-59 375-0 500 216-58 32498 7 3-03 437-5 600 259-90 38748 8 3-46 500-0 700 302-22 45622 9 3-89 562-5 800 346-54 52496 10 4-33 624-9 900 389-86 58746 15 6-49 937-4 1000 433-18 64996 20 8-66 1249-9 To Bend Glass Tubes. (Spon.) If. a sudden bend is wanted, heat only a small portion of the tub* to a dull red heat, and bend it with the hand held at the opposite ends. If the bend is to be gradual, heat an inch or two of it in length SATURATED HYDROCARBONS. 325 previous to bending it. If a gradual bend on the one side and a sharp one on the other, as in retorts, a little management of the tube in the flame, moving it to the right and left alternately at the same time as it is turned round, will easily form it of that shape. In bending glass, the part which is to be concave is to be the part most heated. An ordinary gas flame is quite sufficient* to bend glass by, but that of a spirit lamp is better. Series I. Paraffin Series, Marsh Gas. Saturated Hydrocarbons. (E. L. Price.) Generic Formulas CnH 2 n + 2. Illumina- Volume of Name of Hydrocarbon. Formula. Boiling Point F. Specific Gravity Water =1. ting Power. Candles, per 5 Cubic Gas from 1 Gallon GOF. 30 Inches Feet. Barometer. Methane . CH 4 gas gas 5-0 Ethane . C 2 H 6 gas gas 35-0 Propane . C 3 H 8 gas gas 53-9 Butane ^HIO 34 6 37 Pentane . C 5 H 12 98 102 626 620 - 6 F. 31 Hexane ^6^14 156 663 620 ' 6 F. 27 Heptane . CfHje 209 700 32 F. 25 Octane CgHig 258 . 719 320 F. 22 Nonane ' . C9H2Q 297 .728560-5 F. 20 Decane CioH 22 331 334 739560.5 F. 18 Endecane . CllH24 356 359 765610 F. 17 Dodecane . Ci 2 H 26 392_395 .757640.4 F. 16 Series II. Olefine Series, Saturated Hydrocarbons. (E. L. Price.) Generic Formula CnH 2 n. Name of Hydrocarbon. Formula. Boiling Point F. Specific Gravity Water =1. Illumina- ting Power. Candles, per 5 Cubic Feet. Volume of Gas from 1 Gallon 60F. 30 Inches Barometer. Ethylene . Propylene . Butylene . Pentylene . Hexylene . Heptylene. Octylene . C 2 H 4 C 8 H 6 C 4 H 8 QHio C 6 H 12 C?Hi4 CeHje gas gas gas 91 108 154 158 205 . 257 gas gas gas 655M F. 699320 F. 739630.5 F. .723620.6 F. 68-5 4 123-0 5 33 30 27 23 Ordinary coal gas of 15 to 16 candle power contains about 2 per cent, benzene. The effect of washing gas with mineral oil of '840 specific gravity is to reduce the illuminating power of the gas by about 50 per cent. The stability of nearly all hydrocarbons is destroyed when subjected to temperatures above 2,000 F. (B. H. Thwaite.) 326 GAS ENGINEER'S POCKET-BOOK. Bromide of potassium or concentrated sulphuric acid will absorb unsaturated hydrocarbons, but does not affect in diffused daylight the gaseous members of the saturated hydrocarbons. A piece of rag moistened with a mixture of terebene, linseed oil, and turpentine, and rolled into a ball, rose in temperature from 20 C. to 87 C. in the first hour, and began to fume ; and in the next hour increased to 310 C., fuming strongly ; half-an-hour later the rag burnt at a temperature of 360 C. (T. Wilton.) Corks freshly cut have been found to contain an appreciable quantity of ammonia, and may cause errors in gasworks analysis. Elastic Force or Tension of Aqueous Vapour in Inches of Mercury. Temp. Temp. Force. Force. Temp. Temp. Force. Force. Fahr. Cent. Inches. M.m. Fahr. Cent. Inche^ M.m. 320 1-81 4-6 67 19-4 662 16-8- 33 0-55 188 4-8 68 20-0 685 17-391 34 1-1 196 5-0 69 20-5 709 17-9 35 1-65 204 5-2 70 210 733 18-6 36 2-2 212 5-4 71 21-65 758 19-25 37 2-75 220 5-6 72 22-2 784 19-9 38 3-3 229 5-8 73 22-75 811 20-55 39 3-85 238 6-05 74 23-3 839 21-3 40 4-4 248 6-3 75 23-85 868 21-95 41 5 257 6-534 76 24-4 897 22-7 42 5-5 267 6-75 77 25-0 927 23-5 43 6-1 278 7-0 78 25-5 958 24-3 44 6-6 288 7-3 79 26-05 990 25-05 45 7-15 299 7-55 80 26-6 1-023 25-9 46 7-7 311 7-9 81 27-15 1-057 26-75 47 8-25 323 8-15 82 27-7 1-092 27-6 48 8-8 335 8-5 83 28-25 1-128 28-45 49 9-45 348 8-85 84 28-8 1-165 29-4 50 10 361 9-165 85 29-45 1-203 30-55 51 10-55 374 9-5 86 30-0 1-242 31-548 52 11-11 388 9-9 87 30-55 1-282 53 11-65 403 10 ; 25 88 3M 1-324 54 12-2 418 10-6 89 31-65 1-366 55 12-75 433 10-95 90 32-2 1-410 56 13-3 449 11-4 91 32-75 1-455 57 13-85 460 11-8 92 33-3 1-501 58 14-45 482 12-25 93 33-85 1-548 59 15 500 12-7 9t 34-4 1-597 60 15-55 518 13-15 95 35-0 1-647 61 16-05 537 13-55 96 35-5 1-698 62 16-06 556 14-1 97 36-05 1-751 63 17-15 576 14-55 98 36-6 1-805 64 17-7 596 15-1 99 37-15 1-861 65 18-3 617 15-7 100 37-7 1-918 66 18-9 639 16-2 WEIGHT OF AQUEOUS VAPOUR. 327 Volume of 1 Ib. Air at Atmospheric Pressure equals 14-7 Ibs. per Square Inch. Tempera- ture. Volume Tempera- ture. Volume. Tempera- ture. Volume. Degrees Fahr. Cubic Feet. Degrees Fahr. Cubic Feet. Degrees Fahr. Cubic Feet. 11-583 230 17-362 525 24-775 32 12-387 240 17-612 550 25-403 40 12-586 250 17-865 575 26-031 50 12-840 260 18-116 600 26-659 62 13-141 270 18-367 650 27-915 70 13-342 280 18-621 700 29-172 80 13-593 290 18-870 750 30-428 90 13-845 300 19-121 800 31-685 100 14-096 320 19-624 850 32-941 120 14-592 340 20-126 900 34-197 140 15-100 360 20-630 950 35-453 160 15-803 380 21-131 1,000 36-710 180 16-106 400 21-634 1,250 42-990 200 16-606 425 22-262 1,500 49-274 210 16-860 450 22-890 2,000 61-836 212 16-910 475 23-518 2,500 74-400 220 17-111 500 24-146 3,000 86-962 To Find the Weight of Aqueous Vapour in Air. (1) Weigh calcium chloride in a small basin ; cover the basin with a bell jar. Suppose the bell jar contains 1 cubic foot of air, weigh the basin after some time. The increase in weight will be the amount of aqueous vapour in 1 cubic foot of air. (2) Place calcium chloride, or pumice-stone dipped in strong sulphuric acid, in tubes (both substances absorb aqueous vapour). Weigh the tubes ; then pass 20 gallons of air through them. The increase in weight equals the amount of aqueous vapour in 20 gallons. This forms a chemical hygrometer. The maximum pressure of a vapour depends upon temperature and the kind of liquid used. At different temperatures the maximum pressure of water vapour has been carefully determined. Temperature C. Pressure inMilli- metres. Temperature C. Pressure in Milli- metres. 32 0-320 15 12-699 20 0-927 18 15-357 10 2-093 20 17-391 4-600 50 91-981 4 6-097 70 233-093 10 9-165 90 525-450 12 10-457 100 760-000 328 GAS ENGINEER'S POCKET-BOOK. Weight of I cubic foot dry air at 60 F. and 30 inches press of mercury is about 537 grains. Composition of the Atmosphere. By volume oxygen = 20*8, by weight = 23 nitrogen = 79-2, =77 It also contains a little ammoniacal gas, and from 3 to 6 parts in 10,000 of its volume of CO 2 . Carbon dioxide in atmosphere equals about 4 volumes per 10,000 of air. 1 cubic foot water at ordinary temperature and pressure dissolves 1 cubic foot C0 2 . The higher the temperature, the greater the amount of aqueous vapour held in suspension in the gas. The corrected volume of dry gases for both temperature and pressure equals observed volume X observed pressure X 17-33 observed temperature + 460 because the product of the volume and pressure of a gas is pro- portional to the absolute temperature. The density of liquid air is 910. (Dewar.) 100 cubic inches oxygen weigh 34-29 grains. 100 hydrogen 2'14 Minimum Quantity of Oxygen that will Support Combustion. (Professor Clowes.) Paraffin flame 16-6 per cent, oxygen. Candle 15'7 Methane 15-6 CO 13-35 Coal gas 11'35 Hydrogen 5'5 The quantity of moisture in coal gas saturated 20 C. and 760 millimetres equals 2 per cent, which has the effect of reducing the illuminating power 3' 3 per cent. 1 grain hydrogen occupies 46'73 cubic inches. To Find the Speed of Sound in Air. Let A = distance between the observer and the cannon in feet. B = seconds that elapse between seeing the flash and hearing the report. C as feet per second. EXPLOSIVE MIXTURES. 329 Force of Explosive Mixtures of Air and Glasgow Coal Gas, (Dugald Clerk.) Mixture. Maximum Pressure of Explosives Time of Explosion. Gas. Air. Square Inch. 1 volume 13 volumes 52 0-28 seconds. 1 11 63 0-18 1 9 ,, 69 0-13 1 7 89 0-07 1 5 96 0-05 Heat of explosion of gun cotton = 2650 C. = 4802 F. Explosive mixtures are more readily kindled upwards by a flame placed below them, than downward by one placed above them. Limiting Explosive Mixtures of Gases and Air, (Professor Clowes.) Upward Kindling. Downward Kindling. Per cent. Gas. Per cent. Gas. Per cent. Gas. Methane 5 to 13 6 11 Coal gas 5 to 28 9 22 Water gas 9 to 55 Hydrogen 5 to 72 CO 13 to 75 Ethylene 4 to 22 Coal gas, horizontal tube, 10-3 per cent, to 23 per cent. (L. T. Wright.) 10-3 per cent, of coal gas (18'75 candles and -45 specific gravity (air equals 1)) and 89*7 per cent, air is the lowest limit of an explosive mixture. 23 per cent, coal gas as above and 77 per cent, air is the highest limit. (L.T.Wright.) The limiting percentages of explosive gaseous mixtures are : For methane, 5 and 13 ; for hydrogen, 5 and 72 ; for carbon monoxide, 13 and 75 ; for ethylene, 4 and 22 ; for water gas, 9 and 55 ; for coal gas, 5 and 28. It was also proved that many mixtures which were outside, but close to, the above limits, and which could not be fired from above could be fired from below. An exceedingly small quantity of coal dust in air is sufficient to cause an explosion. 330 GAS ENGINEER'S POCKET-BOOK. Expansion by Heat and Melting Points (F.). Expansion. Melting point in degrees F. 1 1 Part in 180 1 Part in Fire brick .... 365,220 2,029 Granite . . from 187,560 1,042 ... to 228,060 1,267 Glass rod . . . . 221,400 1,230 tube. 214,200 1,190 crown . . . 211,500 1,175 plate 209.700 1,165 Platina 208,800 1,160 4,593 Marble, granular white dry 173,000 961 moist 128,000 711 black com- pact .... 405,000 2,250 Antimony . . . . 166,500 925 883 Cast iron .... 162,000 900 1,920 to 2,800 Slate 173,000 961 Steel 151,200 840 2,370 to 2,550 blistered . . . 159,840 888 untempered 167,400 930 tempered yellow . . 131,400 730 hardened . 146,800 816 annealed . . . 147,600 820 Iron, rolled 149,940 833 3,000 to 3,500 soft forged . . . 147,420 819 wire .... 146,340 813 Bismuth . ... 129,600 720 500 Gold, annealed . 123,120 684 2,058 Copper . . average Sandstone .... 104,400 103,320 580 574 1,975 Brass . . average 97,740 543 1,853 wire. 94,140 523 Silver 95,040 528 1,866 Tin . . . average 87,840 488 443 Lead . . . average 62,180 351 612 Pewter .... 78,840 438 Zinc (most of all metals) . 61,920 344 680 to 772 White pine . . . . 440,530 2,447 LBS. WATER HEATED AND COo PRODUCED. 331 Lbs. Water Heated and C0. 2 Produced from Various Gases. (Letheby.) Per Ib. Lbs. of Water Heated, O Air CO 3 Per Re- Viti- Pro- Per Ib. Cubic ' Per Ib. quired. ated. duced. Foot. O used. Cubic Feet. Cubic Feet. Cubic Feet. Lbs. Lbs. Lbs. H 93-4 467 62,030 329 7,754 Marsh gas . . . 47-2 826 23-6 23,513 996 5,878 Olefiant gas . 40-5 878 27-0 21,344 1,585 6,225 Propylene . . . 40-5 878 27-0 21,327 2,376 6.220 Butylene 40-5 878 27-0 21,327 3,168 6,220 Acetylene . . . 36-3 909 29-1 18,197 1,251 5,914 Benzole 36-3 909 29-1 18,197 3,860 5,915 C0 2 6-7 371 13-5 4,325 320 7,569 CS 2 . 14-9 689 5-0 6,120 1,239 4,845 H 2 S . 16-7 630 7,444 671 5,271 Cyanogen 14-5 435 14-5 6,712 925 5,142 Coal gas (common) . . 37-5 618 17-6 21,060 650 6,816 (cannel) 31-0 698 220 20,140 760 6,503 Wood spirit . . . 25-3 422 11-8 9,547 819 6,363 Lbs. Water Heated and C0 2 Produced from Various Substances. (Letheby.) Per Ib. Lbs. of Water Heated, 1F. O Air C0 3 Per Re- Viti- Pro- Per Ib. Cubic Per Ib. quired ated. duced. Foot. O used. Cubic Feet. Cubic Feet. Cubic Feet. Lbs. Lbs. Lbs. Alcohol . . . 24-6 533 16-4 12,929 1,597 6,195 Camphine . . . 38-9 880 27-8 19,573 7,134 5,942 Carbon 31-0 943 31-5 14,544 5,447 Ether . . . Paraffin , 30-9 40-5 664 878 20-4 27-0 16,249 21,327 3,217 6,158 6,220 oil . 40-5 878 27-0 21,327 6.220 Rape oil ... 38-7 801 24-3 17,752 6J23 Sperm oil . . . 38-7 801 24-3 17,230 6,088 Spermacetti . 37-0 815 25-2 17,589 6.088 Stearic acid . . . 34-6 783 24-0 17,050 0,061 Stearine 34-4 527 14-2 18,001 6,143 Wax .... 37-7 829 25-6 15,809 4,995 332 GAS ENGINEER'S POCKET-BOOK, Temperature of Combustion. (Letheby and Others.} Open Flames. Closed Vessel. InO. In Air. InO. In Air. H Degrees. 14,510 Degrees. 5,744 Degrees. 19,035 Degrees. 7,852 Marsh gas . . . 14,130 4,762 18,351 6,680 Olefiant gas 16,535 5,217 21,344 7,200 Propylene . . . 16,522 5,239 21,327 7,177 Butylene 16,522 5,232 21,327 7,177 Acetylene . . . 17,146 5,142 22,006 7,009 Benzole 17,146 5,142 22,006 7,009 C0 2 .... 12,719 5,358 16,173 7.225 CS 2 15,280 4,314 20,031 5,917 H 2 S .... 13,688 4,388 17,542 6,026 Cyanogen 13,488 5,028 17,645 6,167 Coal gas (luminous) . 14,320 5,228 18,101 7,001 Cannel gas . 14,826 5,121 19,046 7,186 Wood spirit . . . 11,435 4,641 14,902 6,347 Alcohol 13,305 4,831 17,223 6,629 Ether .... 14,874 5,150 19,225 6,953 Camphine 16,271 5,026 20.953 6,922 Expansion of Liquids, from 32 to 212 F. Volume at 32 = 1. Liquid. Volume at 212 Expan- sion. Liquid. Volume at 212 Expan- sion. Alcohol . Nitric acid . Olive oil Turpentine . Air . M100 1-1100 1-0800 1-0700 1-374 a A i 3 Sea water Water . . Mercury Spirits of wine 1-0500 1-0466 1-018 1-110 A * S a To find the weight of water that can be evaporated from and at 212 F. in Ibs. per Ib. of fuel 15 { o/ of + (4-28 X % H)} or, , Total heat of combustion 966 Coefficient of the Expansion of Gases. (Charles's Law.) AH gases expand ^rd part of their volume for every degree Centi- grade increase in temperature above ; or, in decimals, 0'00366B. FREEZING POINTS. 333 Expansion and Weight of Water from 32 to 500 F. Tempera- 1 ture. Relative Volume by Expansion. Weight of 1 Cubic Foot. Weight of 1 Gallon. H Relative Volume by Expansion. Weight of 1 Cubic Foot. Weight of 1 Gal on. Deg. F. Lbs. Lbs. Deg.F. Lbs. Lbs- 32 1-00000 62-418 10-0101 125 1-01239 61-654 9-887 35 99993 62-422 10-0103 130 1-01390 61-563 9-873 39-1 99989 62-425 10-0112 135 1-01539 61-472 9-859 40 99989 62-425 10-0112 140 1-01690 61-381 9-844 45 99993 62-422 10-0103 145 1-01839 61-291 9-829 46 1-00000 62-418 10-0101 150 1-01989 61-201 9-815 50 1-00015 62-409 10-0087 155 1-02164 61-096 9-799 52-3 1-00029 62-400 10-0072 160 1-02340 60-991 9-781 55 1-00038 62-394 10-0063 165 1-02589 60-843 9-757 60 1-00074 62-372 10-0053 170 1-02690 60-783 9-748 62 1-00101 62-355 10-0000 175 1-02906 60-665 9-728 65 1-00119 62-344 9-9982 180 1-03100 60-548 9-711 70 1-00160 62-313 9-9933 185 1-03300 60-430 9-691 75 1-00239 62-275 9-9871 190 1-03500 60-314 9-672 80 1-00299 62-232 9-980 195 1-03700 60-198 9-654 85 1-00379 62-182 9-972 200 1-03889 60-081 9-635 90 1-00459 62-133 9-964 205 1-0414 59-93 9-611 95 1-00554 62-074 9-955 210 1-0434 59-82 9-594 100 1-00639 62-022 9-947 212 1-0466 59-64 9-565 105 1-00739 61-960 9-937 250 1-06243 58-75 9-422 110 1-00889 61-868 9-922 300 1-09563 56-97 9-136 115 1-00989 61-807 9-913 400 1-1 54-25 8-700 120 1-01139 61-715 9-897 500 1-2 51-16 8-204 Freezing Points. Substances. Bromine freezes at Oil anise olive rose Quicksilver Water Centigrade. Fahrenheit. , 20 =40 10 = 50 10 = 50 15 = 60 39-4 = 39 = 32 334 GAS ENGINEER'S POCKET-BOOK. Melting Points and Expansions of Metals. Metals. Specific Heat. Melting Point. Coefficient of Expansion. C. F. Per Degree F. Aluminium, pure 231 | 704 to 899 1,300 to 1,650 I -00001235 Antimony . . . '0508 I 432 to 621 810 to 1,150 1 -00000601 Asphalt 100 212 Bismuth . . . 031 264 507 0000078 Brass .... 094 899 1,650 00001047 Bronze . . . . 921 1,690 Copper Gold, standard . . 0951 095 1,091 1,180 1,996 2,156 000001 00000821 pure . 1,250 2,282 Iron, cast (grey) . . 130 1,124 2,056 00000616 (white) 129 1,050 to 1,100 1,922 to 2,012 wrought . . 110 1,600 2,912 00000657 Lead .... 031 324 615 00001555 Mercury . . . 033 39-4 -39 . -00009984 Nickel . 109 1,543 2,810 00000695 Platinum . . . 038 1,693 3,080 00000493 Palladium . 1,500 2,732 Silver .... 057 1,001 1,834 00001063 Steel, hard . ) mild . . } 117 f 1,300 1 1,400 2,732 2,552 00000695 00000672 Tin ... . 057 230 444 0000121 Zinc .... 096 401 754 00001636 Melting Points of Solids. Substance. Melting Points. Substance. Melting Points. C. F. C. F. Butter 33-0 91 Sodium chloride 776 1,429 Calcium chloride 726 1,339 sulphate 865 1,589 C0 2 . 108 Spermaceti 49 120 Ice Iodine 115 32 239 Stearine . . j 43 to 49 109 to 120 Nitro-glycerine . 7 45 Sulphur . 112 234 Phosphorus 44 111 Tallow . . . 99 92 Potassium iodate 560 1,040 Turpentine 10 14 iodide 634 1,173 Wax, bees' . . 65 150 Silver nitrate . 198 389 paraffin . 45 114 BOILING POINTS. 335 Melting Points of Alloys, Tin. Lead. Bismuth. Softens at. Melts at, Degrees F. Degrees F. 5 3 8 202 1 1 1 254 2 2 1 292 4 4 1 320 2 1 340 4 1 365 1 1 365 371 6 1 381 2 6 372 383 2 7 377-5 388 2 8 . 395-5 408 1 2 441 1 3 482 1 5 511 Boiling Points, Latent Heat of Evaporation, and Heat from 32 F. of 1 Ib. Boiling Point. Latent heat of Evapo- ration of 1 Ib. Volume at 32 F. = 1. Volume at 212 F. equals. Total heal from 32 F. of 1 Ib. C. F. Alcohol .... 78 173 374 1-110 461-7 Ammonia . ... 60 140 Benzine .... 80 176 Bisulphide of carbon . . 47 116 Bromine .... 63 145 Ether 35 95 nitrous . 14 57 Iodine 181 347 Linseed oil ... 314 597 Mercury . . , 342 648 1-018 Nitric acid __ 1-110 Olive oil . 315 600 1-080 Paraffin .... 280 536 Petroleum . . . . 158 316 Quicksilver 350 662 Salt 413 775 Sulphur .... 236 447 Sulphuric ether . . . 38 100 175 210-4 Sulphurous acid 10 14 157 315 124 ro70 256-6 Water .... 100 212 965-2 1-047 1146-1 sea . 101 213-2 1-050 saturated brine 108 226 Wood spirit . . . 66 150 475 545-9 Zinc . 1,040 1,904 1-0029 336 GAS ENGINEER'S POCKET-BOOK. The specific heat of a body is the ratio of the quantity of heat required to raise that body 1 in temperature, compared to the quantity of heat required to raise an equal weight of water from 39 to 40 F. Specific Heats. Acid hydrochloric . . -600 Petroleum o -434 Alcohol . . '659 Phosphorus . -2503 Benzene . . . . -3932 Quicklime . -2169 Brickwork . . . -192 Soda . . f . -2311 Chalk . . ! . . -2148 Stonework . . ; . . -197 Carbon . . '2411 Sulphur . -2026 Charcoal . . -2415 Sulphuric acid, density 1 87 -3346 Coal, anthracite . . . -2017 ?> 5> ^ 30 '6614 bituminous . -2411 Sulphate of lead . -0872 Coke . . '203* lime . {'. . -1966 Ether . . . . -521 Turpentine . . V . '416 Glass . . . -1937 Vinegar . -92 Graphite . . -2019 Water at 32 F. . 1-0 Ice ... . . -504 212 F.. V . 1-013 Magnesium limestone . -2174 Wood, average . -550 Marble . . -2129 spirit . -6009 Olive oil . . -3096 * Increases as temperature rises. The atomic specific heat of carbon is expressed by the following formula : From to 250 C., it is C = 1-02 + 0"0077 ; from 250 to 1,000 C., it is C = 3-54 + 0'0246. (MM. Uchene and Biju-Duval.) Specific Heats of Oases, &c. Equal Pressure. Equal Volume. Equal Pressure. Equal Volume. Acetone . 0-4125 0-8244 Hydrogen 3-4046 0-2359 Air . 0-2377 0-2374 H 2 S . 0-2432 0-2857 Alcohol . 0-4534 0-7171 Hydrochloric vapour 0-4513 0-3200 acid 0-1845 0-2333 Ammonia . . 0-5083 0-2966 Light carburet- Benzole . 0-3754 1-0114 ted hydrogen 0-5929 0-4683 Binoxide of ni- Marsh gas . . 0-5929 0-3277 trogen . . 0-2315 0-2406 Nitrogen . 0-2440 0-2370 Bromine . ... . 0-0555. 0-3040 Nitric acid . . 0-2317 0-2406 Chlorine . . 0-1210 0-2962 oxide . 0-2262 0-3447 CO . 0-2479 0-2370 Oxygen . 0-2182 0-2405 C0 a . 0-2164 0-3307 Steam,saturated 0-3050 CS a . 0-1570 0-4140 gas . . 0-4750 0-2984 Chloroform. . 0-1567 0-6461 Sulphurous an- Ether 0-4810 1-2296 hydride 0-1553 0-3414 Ethylene . . 0-4040 0-4106 Turpentine . . 0-4160 2-3776 FREEZING MIXTURES. 337 Specific Heat of Water at Different Temperatures, Heat to Raise Heat to Raise Tempera- ture, F. Specific Heat. 1 Ib. Water from 32 F. to given Tempera- Tempera- ture, F. Specific Heat. 1 Ib. Water from 32 F. to given Tempera- ture. ture. Degrees. Units. Degrees. Units. 32 I'OOOO o-ooo 248 1-0177 217-449 50 1-0005 18-004 266 1-0204 235-791 68 1-0012 36-018 284 1-0232 254-187 86 10020 54-047 302 1-0262 272-628 104 1-0030 72-090 320 1-0294 291-132 122 1-0042 90-157 338 1-0328 309-690 140 1-0056 108-247 356 1-0364 328-320 158 1-0072 126-378 374 1-0401 347-004 176 1-0089 144-508 392 1-0440 365-760 194 1-0109 162-686 410 1-0481 384-588 212 1-0130 180-900 428 1-0524 403-488 230 1-0153 199-152 446 1-0568 422-478 Freezing Mixtures. Fall in Temperature. Degrees Cold pro- duced. Nitrate of ammonia . Water .... 1 part) 1 J From + 50 to + 4 F. 46 F. Dilute sulphuric acid . Snow . ... 2 3 + 32 - 23 55 Muriate of lime . Snow . . . . + 20 - 48 68 Phosphate of soda 9 Nitrate of ammonia . 6 ii + 50 - 21 71 Dilute nitric acid ^ Common salt . . . 1 From any temperature Snow or powdered ice 2 to - 5 F. Common salt Nitrate of ammonia . Snow or powdered ice 5 5 12 From any temperature to-25F. Sulphate of sodium . Dilute nitric acid . . 3 ) 2 J From 10 C. to - 18 C. Phosphate of sodium . 6 i Dilute nitric acid ' 5 I ii ii ^" Crystallized calcium chloride . 10 I ,, ,, -50 Snow . . . . 7 J Water (H 2 0) when freezing expands from 1 volume to 1-09. G. E. z 338 GAS ENGINEERS POCKET-BOOK. Expansion of Liquids in Volume from 32 to 212. 1.000 parts of water oil ... mercury . spirits of wine atmospheric air become 1,046 1,080 1,018 1,110 1,376 Latent Heat is the heat absorbed by any substance, without raising its temperature, in changing from the solid to the liquid state, or from the liquid to the gaseous state. Latent Heats of Fusion. Mercury Lead Sulphur 2-8 5-4 9-4 Bismuth Silver . Water 12-6 21-1 80-2 Latent Heat Liquefaction. Water at 39 F Bismuth Lead . Mercury 142-65 22-75 9-67 5-09 Silver Tin Zinc. 37-93 25-65 50-63 Comparative Powers of Solids for Conducting Heat. Gold . Platinum Silver Copper . Brass Iron, cast wrought Zinc 1,000 981 973 892 749 562 374 363 Aluminium Tin Lead . Marble . Bismuth . Porcelain Terra Gotta 305 304 180 24 18 12 11 Eelative Heat Conductivity of Metals. Silver equals 1,000. Silver Gold . Copper Mercury Aluminium Zinc Wrought Iron 1,000 981 845 677 665 641 436 Tin . Steel . Platinum Cast Iron Lead . Antimony Bismuth 422 397 380 359 287 215 61 RADIATION OF HEAT, 339 Comparative Powers of Solids for Absorbing or Radiating and Reflecting. Reflecting. Absorbing. Silver, polished . 97 per cent. 3 per cent. Gold .... 95 , 5 Copper 93 , 7 1 >5 Brass, bright polished 93 , 7 5> >5 dead 89 , 11 Speculum metal . . 86 , 14 Tin . 85 , 15 Steel, polished . . 83 17 Platinum, sheet . 83 5, 17 polished 80 20 Zinc' .... 81 19 Mercury . . . 77 23 Iron, wrought, polished 77 23 cast, . 75 25 Silver leaf on glass . 73 27 ., Ice . . . . . 15 85 Glass .... 10 90 Writing paper . . 2 98 ; Water. o 100 Marble .... 2 to 7 98 to 93 Quantity of Heat Lost per Square Unit of Surface. (Peclet.) Excess of Temperature of Gas over Air. 10 . 20 30 . 40 . 50 . Loss in Air. . 8 . . 18 . 29 . . 40 . 53 . Loss in Water. 88 266 5,353 8.944 13^37 Effect of Mixing Water at Different Temperatures. 1 Ib. of water at C. + 1 Ib. of water at 16 C. equals 2 Ibs. of water at 8 C. 1 Ib. of water at C. + 1 Ib. of water at 35 C. equals 2 Ibs. of water at 17-5 C. 1 Ib. of water at 16 C. + 1 Ib. of water at 35 C. equals 2 Ibs. of water at 25-5 C. 1 Ib. of water cooling from 16 to 8 raised the temperature of 1 Ib. from to 8. Convection is the transference of heat by particles. Conduction is the transmission from particle to particle. Z2 340 GAS ENGINEER'S POCKET-BOOK. British Thermal Unit equals quantity of heat necessary to raise 1 Ib. pure water 1 F. from 39-1 to 401. Calorie equals quantity of heat necessary to raise 1 kilogramme pure water 1 C. at or about 4 C. B. T. TJ. X '252 = Calories, or Calories X 3*968 = B. T. U. Joule's Law 1 B. T. D. equals 772 foot Ibs. work performed. Joule's law shows that the quantity of work required to raise the temperature of 1 Ib. of water, weighed in vacuum, from 60 to 61 F. equals 772*55 foot Ibs. at sea level in the latitude of Greenwich ; or the amount of work that is converted into heat by raising 1 Ib. of water 1 C. is 1,390 foot Ibs. (fths of 772). Metals all possess the same atomic heat = 6-4. To convert Fahrenheit to Centigrade 5 fF 32^ - - 9 C. To convert Centigrade to Fahrenheit - f- 32 = F. Comparison of the Value of Coal Gas for Motive Power and Lighting at Different Candle Powers. (C. Hunt.) Illuminating Power of Gas. Candles. Consumption per I.H.P. per Hour. Cubic Feet. Value for Motive Power. Value for Lighting. 11-96 30-31 1-000 1-000 15-00 24-41 1-241 1-254 17-20 22-70 1-335 1-438 22-85 17-73 1-709 1-910 26-00 16-26 1-864 2-173 29-14 15-00 2-020 2-436 Calorific Value of Coal Gas. (T. L. Millar.) Illuminating Power. Heating Power per Cubic Feet. Glasgow . Liverpool . . . Kilmarnock Manchester . . . Birmingham . London . . . Hoboken Berlin . . . 21 candles 21 25 16 and 19 candles 17* candles 16 813 heat units 770 680 654 639 624 617 549 Theoretical value in heat units of 1 cubic foot of gas of 16 candle power equals 660 to 670 (1 Ib. water heated 1 F.). HEAT UNITS FROM DIFFERENT SUBSTANCES. 341 The number of heat units obtainable in practice is : In the best bath heaters, about 600 ; in the best boiling burners, about 375. Effective heating duty of coal gas in small vessels equals 300 to 620 Effective heating duty of coal gas in ordinary flat-bottomed vessels with projecting rivets equals 520 units. Effective heating duty of coal gas in domestic pans and kettles equals 300 units. Effective heating duty of coal gas in small pans and kettles equals 150 units. (T. Fletcher.) 15 candle gas gives 620 heat units per cubic foot. 19 800 (N. H. Humphreys.) Carbon, when combined with hydrogen to form defiant gas (C 2 H 4 ) and acetylene (C 2 H 2 ), has a locked-up heat energy, as compared with the carbon forming marsh gas (CH^) of 31,300 and 75,430 heat units respectively which are developed as light and heat when the gases are burned. (YV. Young.) Heat Units generated by Complete Combustion. B.T.U. gross. Per Ib. net. B.T.U. gross. Per c. ft. net. Calories. Hydrogen (H) 62535 60791 326-2 272 34462 Carbon (C) to C0 2 . . . 14500 12906 7700 co 2 . . . 2495 1416 CO to C0 2 .... 4478 4234 323-5 24 OU Sulphur (S) . 4102 3916 Sulphuretted hydrogen (H 2 S) 4940 4420 450 403 Methane (Marsh Gas) (CH 4 ) . Ethane (C 2 H 6 ) .... Propane (C 3 H 8 ) 23620 21420 1024 1764-4 2521 919 3087 Butane (C 4 rI 10 ) . . . 3274 Ethylene (C 2 H 4 ) . 21713 20460 1603 1510 Propylene (C 8 H 6 ) . . . 21220 19830 2B77 2242 Butylene (C 4 H 8 ) . 20900 1970U 3921 2696 Acetylene (C,H 2 ) . . . 1476-7 Benzene (C G H C ) 17780 17100 3718 3574 Coal gas (17 candles) . . i <;;>< KS 650 Water gas .... 8200 7500 304 330 Producer gas . . . . 1897 160 water gas 983 The maximum temperature obtainable by the combustion of C equals about 5,000 F. The maximum temperature obtainable by the combustion of H equals about 5,800 F. 342 GAS ENGINEER'S POCKET-BOOK. One ton coal = 8,353,846-640 calories. 10,000 cubic feet gas . . . . = 1,635,000-000 An average Lancashire coal is said to have a calorific power of 13,890, which means that 1 Ib.of the coal would raise 13,890 Ibs. water through 1 F. of temperature. Relative calorific intensity of coke per Ib. = 2,114 C. ,i ,, tar = 2,486 C. (F. G. Dexter.) Latent heat >f steam . . .536 thermal units water .... 79 Maximum heat obtainable by air blast . . 2,500 The boiling point of hydrogen is found to be 234*5 below zero. Benzene or benzol (C 6 H 6 ) boils at 81 and freezes at C. Naphthalene (C 10 H ft ) melts at 80 and boils at 217 C. Anthracene (C 14 Hi ) melts at 213 and boils at a little above 360 C. To prepare Acetate of Lead Test Papers. Moisten sheets of bibulous paper with a solution of 1 part sugar of lead in 8 or 9 parts water and hold each sheet, while still damp, over the surface of a strong solution of ammonia for a few moments. Such papers will become tinged if subjected to gas containing O'OOl per cent, by volume of H 2 S for 24 hours, light being excluded during that time. To make Turmeric Papers. Six parts methylated spirit to 1 of turmeric powder by weight, to be well shaken from time to time for 3 days. Decant clear liquid and soak sheets of botanical or filtering paper in it, dry and keep in the dark. The papers should be a full yellow colour. One grain or more NH 3 per 100 cubic feet will cause the colour to change to brownish tint. To make Red Litmus Paper. Dissolve 1 oz. powdered blue litmus in 6 ozs. cold distilled water and shake well, allow to dissolve and filter, add gradually dilute H 2 S0 4 until it is changed to a red tint ; soak sheets of glazed paper in it and dry. These papers turn blue when exposed to gas contain- ing NH 3 . To make Lime Water. Dissolve 4 ozs. caustic lime in 1 quart water, shake occasionally, decant the clear liquid and keep it free from C0 2 . If gas containing C0 2 is bubbled through a portion of above, it forms CaC0 3 , the liquid becoming milky, thus : CaO + C0 a CaC0 3 . TO PREPARE INDICATORS. 343 If still clear, after bubbling for 3 minutes, the gas is probably quite free from C0 2 . All H 2 S must be removed from the gas by means of oxide of iron before making above test. To prepare Litmus for Indicating Acids and Alkalies. Digest solid litmus in hot water and evaporate to a certain degree, add a small quantity acetic acid. Evaporate again and add methy- lated spirit. Filter the precipitate and wash with spirit, dissolve with warm water and add a small quantity nitric acid. Keep exposed to the air to preserve the colour. Free C0 2 effects the change in colour of the solution. To prepare Cochineal for Analysis of Ammonia, Take 1 part methylated spirit and 4 parts water, keep at a gentle heat for some hours with about 10 grammes cochineal powder to every 1,000 cubic centimetres of the solution, cool and decant the clear liquid. Its yellow colour is changed to red by alkalies, and to yellow again by mineral acids and is not affected by C0 2 . The acid must be added to the alkali solution when using this indicator. To prepare Methyl-orange for estimating Ammonia in Gas. Dissolve 1 gramme of methyl-orange, in powder, in methylated spirit and make up to 1 litre with a solution of one part water and one part methylated spirit. The colour is changed to yellow by alkalies and then to red by acids ; it is not affected by C0 2 . To prepare Phenol-phthalein. Make an alcoholic solution which should be colourless, but an alkali causes it to become red, and this is again destroyed by an acid. Phenol-phthalein is affected by the presence of ammonia salts or C0 a . Standard Solution. For testing gas liquor (Will's test) 125 cubic centimetres NH 3 (specific gravity '880) to 1 litre H 2 0. 10 per cent, acid (specific gravity of strong acid). /I -067 = 9-8 per cent. acid. \10 parts to 90 of water. 10 per cent, acid = 1064-4 specific gravity. To prepare Standard Acid Solution for test of Ammonia. Measure a gallon of distilled water in a clean earthenware jar or other suitable vessel. Add to this 94 septems of pure concentrated sulphuric acid and mix thoroughly. Take exactly 50 septems of the liquid and precipitate it with barium chloride in the manner prescribed for the sulphur test. The weight of barium sulphate which 50 344 GAS ENGINEER'S POCKET-BOOK. septems of the test acid should yield is 13*8 grains. The weight obtained with the dilute acid prepared as above will be somewhat greater, unless the sulphuric acid used had a specific gravity below 1'84. Add now to the dilute acid a measured quantity of water, which is to be found by subtracting 13'8 from the weight of barium sulphate obtained in the experiment and multiplying the difference by 726. The resulting number is the number of septems of water to be added. If these operations have been accurately performed, a second precipitation and weighing of the barium sulphate obtainable from 50 septems of the test acid will give nearly the correct number of 13'8 grains. If the weight exceeds 13'9 grains, or falls below 13-7 grains more water or sulphuric acid must be added, and fresh trials made until the weight falls within these limits. The test-acid thus prepared should be transferred at once to stoppered bottles which have been well drained, and are duly labelled. (Metropolitan Gas Keferees.) To prepare the Standard Solution of Ammonia. Measure out as before a gallon of distilled water, and mix with it 20 septems of strong solution ammonia (specific gravity 0'88). Try whether 100 septems of the test alkali thus prepared will neutralize 25 of the test acid, proceeding according to the -direction given sub- sequently as to the mode of testing. If the acid is just neutralized by the last few drops, the test-alkali is of the required strength ; but if not, small additional quantities of water or of strong ammonia solution must be added, and fresh trials made, until the proper strength has been attained. The bottles in which the solution is stored should be filled nearly full and well stoppered. (Metropolitan Gas Keferees.) To prepare Potassium Hydroxide for determining C0 a . Use commercial stick potash, not purified by alcohol, dissolve 8 ozs. in a pint of distilled water for careful and exact tests, but for ordinary work, a more dilute solution may be used. To prepare Bromine for determining the Hydrocarbons. Make an aqueous solution of bromine almost saturated. Before measuring the absorption the vapour of the bromine must be removed by potassium hydroxide solution. A solution of bromine in potassium bromide is sometimes used. To prepare Cuprous Chloride Solution for determining CO. For the hydrochloric acid solution, place 100 grammes of precipi- tated cuprous chloride in a bottle and pour on 500 cubic centimetres of concentrated hydrochloric acid, into which put some copper spirals so as to reach to the top of the liquid. Sor the ammoniacal solution, place 40 grammes of precipitated cuprous chloride in a bottle and fill up with 400 cubic centimetres of water, into this bubble some ammonia gas, made by boiling some TO PREPARE NORMAL SOLUTIONS. 345 strong ammonia solution, the fumes from which are carried into the bottle containing the cuprous chloride, until the latter assumes a pale blue colour, then make the solution up to 500 cubic centimetres, and carefully stopper the bottle. To prepare Sulphuric Acid for determining the Hydrocarbons. The acid to be used must be strongly fuming acid (Nordhausen) which on cooling to a slight degree below usual temperatures, deposits crystals readily. It is used either on coke balls thoroughly saturated or in absorption pipettes with glass balls inside. Before measuring the absorption, the acid vapours must be removed by potassium hydroxide solution. To prepare Pyrogallic Acid Solution for determining Oxygen. Dissolve fresh pyrogallic acid in 3 times its weight of water (distilled). After pouring this into the absorption tube, put in eight times the volume of caustic potash solution. The absorption of oxygen is slow and requires about 5 minutes' agitation. To prepare Normal Oxalic Acid. This solution should contain 63 grammes per litre. Dissolve this quantity in distilled water and make up to 1 litre. Test against normal alkali. Do not use this acid with methyl-orange, and keep it out of direct sunlight. To prepare Normal Hydrochloric Acid. This solution should contain 36'5 grammes per litre. Dilute strong hydrochloric acid with distilled water and make it of 1*10 specific gravity at 60 F. Test against normal solution of sodium hydrate and dilute to normal strength. To prepare Normal Sulphuric Acid Solution. This should contain 49 grammes pure H 2 S0 4 per litre. Add strong sulphuric acid to distilled water, and when cool test by means of standard sodium carbonate solution, and add water to reduce to normal strength. When the solution is correct an equal quantity of the acid should exactly neutralize an equal quantity of the alkali. To prepare Normal Solution of Sodium Carbonate. The solution should contain 53 grammes pure Na 2 C0 3 per litre and the Na 2 C0 3 should be dissolved in the water, and, when at normal temperature, the amount made up to the exact quantity by adding distilled water. To prepare Normal Sodium Hydrate Solution. This solution should contain 40 grammes per litre. Dissolve about 44 grammes caustic soda, purified by alcohol, in distilled water, recently boiled and cooled, 346 GAS ENGINEER'S POCKET-BOOK. Or use 25 grammes clean metallic sodium in distilled water. Test with normal acid solution and dilute to proper strength. Specific gravity of solution 50 grammes per litre equals 1-05. 25 septems standard acid neutralize 1 grain NH 3 . 100 ammonia contain 1 grain NH 3 . Equivalent Normal Solutions. Nitric acid .63 grams per litre. Anhydrous carbonate of soda Sulphuric acid Sodic hydrate . Hydrochloric acid . Ammonia . 53 49 40 36-5 17 Degrees of Twaddell's Hydrometer compared with Specific Gravity. Twaddell. Specific Gravity. Twaddell. Specific Gravity. Twaddell. Specific Gravity. Twaddell. Specific Gravity. 1-000 6 1-030 13 1-065 19 1-095 1 1-005 7 1-035 13-4 1-067 20 100 1-4 1-007 7-4 1-037 14 1-070 21 105 2 1-010 8 1-040 15 1-075 21-6 108 2-8 1-014 9 1-045 16 1-080 22 110 3 1-015 10 1-050 16-6 1-083 23 115 4 1-020 10-2 1-052 17-0 1-085 23-2 116 4-4 1-022 11 1-055 18-0 1-090 24 120 5 1-025 12 1-060 18-2 1-091 25 125 5-8 1-029 Degrees Twaddell x 5 + 1' 000 equals specific gravity. Specific gravity - 1-QOO 5 Degrees Twaddell. To find the volume of air required to chemically combine with any fuel to support complete combustion : 1-52 { per cent, of C+3 (per cent, of H) -4 (per cent, of 0) } equals cubic feet per Ib. fuel, of air as at 62 F. and at one atmosphere. In above no notice is taken of the air required by the sulphur, which is only nominal. To find the volume of gaseous products on complete combustion of 1 Ib. fuel as at 62 F. at one atmosphere. (1-52 X per cent, of C) + (5-52 X per cent, of H) To find the weight of gaseous products on complete combustion of lib. fuel as at 62 F. at one atmosphere : (126 x per cent, of C) + (-358 x per cent, of H) LOSS OP LIGHT ON MIXING AIR WITH GAS. 347 To find the total heat of combustion of any fuel containing C and H: 145 { per cent, of C + (4-28 X per cent. H) j- The richer the gas the greater the quantity of required for complete combustion. 1 volume gas requires 5 volumes air for complete combustion. Results of different mixtures of Gas and Air on Light given by Incandescent Burners. (W. Foulis.) Illuminating Power Glasgow Gas. Air. per Cubic Foot- 1 . . . 7 . . . . 13-0 candles. 1 ... 5-8 ... 28-2 1 . . . . 4 . . . . 17-3 With gases of over 50 candle power the addition of small quantities of increases the illuminating power by combining rapidly with the H of the hydrocarbons and therefore not requiring the use of a similar quantity of O combined with N from the air, the N acting merely as a diluent, with low quality gases the quantity of possible to effect an increase is very minute. The addition of a small proportion of oxygen to coal gas was found by Dr. P. Frankland to sensibly increase the illuminating power, but the addition of even a small quantity of nitrogen materially decreases it. 1 per cent. N reduced the luminosity 1 per cent. Loss of Light by the addition of air to Coal Gas. (VVurtz.) Air. Loss of Light. 3-00 15-69 per cent. 4-96 23-83 11-71 41-46 16-18 57-53 25-00 , 84-00 , Loss of Light per Cent, by Mixing Air with Coal Gas. Air, per cent . 1 2 3 4 5 6 7 8 9 10 15 20 30 40 Loss of Light, per cent. 6 11 18 26 33 44 53 58 64 67 80 93 98 100 The reason CO 2 is a more harmful substance than N is that the specific heat of C0 a is nearly half as much again as that of N" and consequently the amount of heat taken up by CO, in being raised to the temperature of the flame is greater than that taken up by nitrogen. One per cent. C0 2 reducing the illuminating power about 4 to 5 per cent. C0 a , air, N, and water vapour, cool and dilute flames. H and CO dilute only. The addition of N to pure ethylene reduces luminosity in propor- tion to its volume, but probably when N is added to coal gas some of the tarry vapours are carried forward by it, and the luminosity is therefore not decreased to the same extent. 348 GAS ENGINEER'S POCKET-BOOK. Comparative Duty of Different Burners with 16-candle Gas. (Professor Lewes.) Burner. Flat flame, No. . > )> 5> J , ,,2. Light per Cubic Foot of Gas. . . 0-59 . 0-85 . 1-22 Burner. Flat flame, No. 6 . 7 >' .. M " Ordinary Argand Light per Cubic Foot of Gas. . . 2-15 . 2-44 2-90 > 3 > >J M * , 5 . 1-63 . . 1-74 ; .^ ' '. 1-87 Standard Regenerative . 3-20 . : . 10-00 Efficiency of Incandescent Burners with Different Quality Gases. (Foulis.) Ordinary Burner (Flat Flame). Incandescent Burner. Illuminating Power Corrected to 5 Cubic Feet Candles per Cubic Foot. Illuminating Power Corrected to 5 Cubic Feet. Candles per Cubic Foot. 23-1 4-6 117-3 23-40 17-9 3-6 90-3 18-07 16-2 3-2 87-9 17-59 14-6 2-9 84-4 16-89 13-5 2-7 81-9 16-39 The following Table gives the results obtained with Edinburgh gas when consumed from various burners : Five cubic feet are equal to : Candle Power. Bray No. 8 . . . . . . 25-00 Bray " Special " No. 8 . . . . 29-43 Bray Adjustable g . , . 5J ] 21-72 26-66 28-37 30-39 36-16 36-76 36-87 28-00 32-35 18-12 20-75 25-00 23-75 28-57 19-41 53-30 61-95 (Professor W. I. Macadam.) With a Union jet CH 4 and C 2 H are non-luminous. Milne's Old Regulator . Spon's Deflector and No. 7 Bray Noleton Duplex (No. Bray) Parkinson Regulator and No. 7. Bray Peeble's Regulator, No. | Welsbach " f Street Burner ; S " Burner C" COMPOSITION OF COAL GAS. 349 Average Composition of London Gas. (Dr. Letheby.) Common Gas. Cannel Gas. Twelve Twenty Candle. Candle. Hydrogen 46-0 27-7 Light carburetted hydrogen . . . 39-5 50-0 Condensable hydrocarbons . 3-8 13-0 Carbonic acid 0-6 o-i Carbonic oxide 7-5 6-8 Aqueous vapour 2-0 2-0 O'l 0.0 0-5 0-4 100-0 100-0 Analysis of London Gas at probably 12 Candle Power. (Thwaite.) Unsaturated hydrocarbons . Benzol .... Marsh Gas .... Carbon anhydride CO H O N Per Cent. 3-84 1-04 35-63 1-41 6-15 47-73 0-30 3-90 Analysis of Coal Gas, London. (Lancet.} Benzene (C a H 6 ) . Olefines (C 2 H 4 ) Carbon monoxide (CO) . Hydrogen (H) . Methane (CH 4 ) Nitrogen (N) . By Volume. 0-55 4-45 7-80 52-90 31-80 2-50 By Weight. 3-98 11-76 20-00 9-84 48-00 6-42 Average Composition of 16 to 17 Candles Caking Coal Gas. (L. T. Wright.) Per Cent. Hydrocarbons capable of absorption, say (CnHm) 4 Paraffins, treated as Marsh gas (CH 4 ) . . 38 CO 6 H . 48 to 50 N 2 350 GAS ENGINEER'S POCKET-BOOK. Electrical Memoranda. A " volt" is the standard or measurement of pressure. An " ampere " is the standard of quantity or measurement of the rate of flow. An " ohm " is the standard of resistance offered by 129 yards of No. 16 copper wire. A "Watt-hour r) is the standard of pressure x amperes x hours. A " unit" is the standard of kilowatt hours (1,000 Watt-hours) and will maintain a 16 c. p. lamp 15 hours. A unit of electricity = 100 cubic feet gas yielding 2 candles per cubic foot = 12 cubic feet gas in Kern burner = 8 cubic feet gas in high pressure burner. 4 Watts will produce 1 c.p., 764 Watts = 11. H.P. Heat from an incandescent electric 16 c. p. lamp is one-twentieth of an equal gas light. 1 unit of electricity gives as much heat as 6 cubic feet gas. 0*746 unit of electricity required to develop 1 B. H.P. per hour, practically, however, 0'85 unit of electricity is nearer. Price per unit x 1,000 = equivalent value of gas per c. ft. required to give 240 c. p. hours thousand feet. Composition of London Gas Companies' Coal Gas. (Professor Lewes.) South Metropolitan. Gas Light and Coke. Commercial. Hydrogen . . . ." 52-22 53-36 52-96 Unsaturated hydrocarbons . . 3-47 3-58 3-24 Saturated hydrocarbons . 34-76 32-69 34-20 CO 4-23 7-05 4-75 C0 2 0-60 0'61 0-75 N 4-23 2-50 5-10 O ; >. 0-49 0-21 o-oo Approximate Analysis of London Coal Gas. (Professor V. B. Lewes.) Unsaturated hydro- carbons, C 2 H 4 Saturated hydro- carbons, C fl H a . Saturated hydro- carbons. CH. CO . ' . N sv D; . by volume 52'0 per cent., by weight 9'6 per cent 3-0 1-0 34-0 5-0 4-5 o-o 0-5 7-7 7-1 49-9 12-8 11-5 O'O 1-4 The illuminating power is far more dependent upon the mode in which the C is combined than upon the actual percentage present in the gas. (W. Young.) COMPOSITION OF ILLUMINATING GASES. 351 Composition of Coal Gas by Volume. H . . . 34 to 53 per cent. CH 4 marsh gas 43 to 36 CO . 6 to 2-7 and C0 2 . 1 to 0-3 percent, C 4 H e defines 13 to 3-0 N . 3 to 5-0 Composition in 100 Volumes. (Sir H. Koscoe.) Illuminating N Power in Candles per 5 H. CH 4 . C n H 3 n. C a H 4 . CO. Cubic Feet. Cannel gas 34-4 25-82 51-20 13-06 (22-08) 7-85 2-07 Coal gas 13-0 47-60 41-53 3-05 ( 6-97) 7-82 Average Composition of Natural Gas in America. H Marsh gas . = 22 per cent. . = 67 Other bodies in small quantities= 11 100 Composition of Coal Gas, Water Gas, and a Mixture. (E. G. Love, 1889.) Coal. Water. Mixture. Hydrogen .... Marsh gas CO Ethylene Ethane Benzol vapour . . . . CO 2 N Specific gravity (calculated) . Calorific power, heat units Air required for combustion of 1 Ib. of gas, Ibs. 39-78 45-16 7-04 4-34 2-04 1-08 0-06 0-50 29-16 24-42 28-33 12-46 0-78 2-88 0-21 1-76 34-47 34-79 17-685 8-40 0-39 2-46 0-54 0-135 1-13 100-00 0-4644 19233-6 14-70 100-00 0-6551 13913-6 10-22 100-00 0-5597 16114-4 13-08 (Extract from paper by E. G. Love, at Baltimore, U.S.A., 1889.) 352 GAS ENGINEEK'S POCKET-BOOK. Comparative Analysis of Coal Gas and Carburetted Water Gas. (A. E. Broadberry.) Description of Gas. H a S. C0 3 . Illumi- nants. o. CO. H. Marsh Gas. *Bal- ance. Unpurified car- buretted water gas . 0-4 6-0 8-8 0-5 27-4 32-3 20-5 4-1 Unpurified coal gas from scrub- ber outlet 1-4 1-3 2-3 1-1 5-2 43-0 37-1 8-6 Combined gas, purified equals 35 per cent.car- buretted water gas 4-8 0-2 13-8 41-1 32-7 7-4 * Probably N. Specific gravity of combined gases, '5, H 2 S and C0 2 , calculated by explosion and absorption. Napthalene is a white, shining, crystalline substance, fusing at 176 F., and boiling at 423 F., but volatilizing when brought into contact with steam. It is not soluble in water, but readily dissolves in alcohol, chloroform, naptha, ether, or carbon disulphide. When napthalene is found, the condition of the coal should first be looked after. The use of wet coal, particularly if slack, should be avoided. A test is to neutralise the liquor with dilute sulphuric acid. If napthalene be present, the liquor assumes a rose colour, and the sulphate solution gives off the peculiar odour distinctly characteristic of napthalene. Carbon Monoxide (CO) is colourless, and has no taste, burns with a lambent blue flame on admixture with oxygen and forms C0 2 . Can be absorbed by a solution of cuprous chloride (Cu 2 C1 2 ). Carbonic oxide is a colourless gas which burns with a bright blue flame forming C0 2 , 2 or 3 per cent, in the air may prove fatal, it has no odour. Specific gravity is '968, 100 cubic inches, weighs 30 grains. Carbon Dioxide (C0 2 ) is colourless and has no smell, and is formed whenever carbon is burnt in excess of air or oxygen. Ethylene or Olefiant Gas (C 2 H*) is colourless and of a sweet taste, burns with a smoky luminous flame in air, explodes loudly when mixed with 3 volumes and fired, the same quantity being required to cause complete combustion. Methane or Marsh. Gas (CH^) is colourless, and burns with a non- luminous flame, is tasteless, and has no odour ; 1 volume CH 4 and 3 volumes explode with a light when 1 volume O remains. Marsh gas weighs 17'41 grains per 100 cubic inches. Density is -659. VALUES OP ILLUMINATING GASES. 353 Relative, Calculated, and Found Values of Gra&es. (Professor V. B. Lewes.) Illuminating Value. Calculated. Found. Methane . 8-4 5-2 Ethane . . 35-0 . . . 35'0 Ethylene . . . 60-9 . . 68'5 Acetylene .... 202-2 . . . 240'0 At between 1,500 and 1,600 F., ethylene is broken up into acetylene aud methane, with formation of benzene ; and at 1,832 F. napthalene and other bodies are formed, and at 2,000 F. are again broken down to acetylene, which then decomposes into C and H. (Professor V. B. Lewes.) Not more than 2 cubic feet per hour of ethylene or ethane can be used in a " London " Argand burner without smoking. The boiling point of ethane is 89-5 at 735 millimetres pressure. The density of liquid ethane was found to be 0-446 at and 0-396 at + 10-5. (Dewar.) Illuminating value of ethane 35, ethylene 68, acetylene 240. Propane is a perfectly colourless liquid, but much more viscous than liquid carbon dioxide. Heptane was found practically insoluble in water. Boiling point of phenanthrene equals 350 C. Olefiant gas burns well, 100 cubic inches weigh 30-57 grains. Density is -981. Acetylene is colourless and burns with a very brilliant flame. Specific gravity is -920. If chlorine is added to acetylene the mixture explodes. Specific gravity of CS 2 equals 1*29. CS 2 boils at 46 C. CS 2 vapour ignites at 300 F. (149 C.) when ethylene is not present. Benzene C 6 H 6 . Toluene C 7 H 8 . Xylene C 8 H 10 . Napthalene C 10 H Heptane C 7 H 16 . 8- Propane is obtained in a state of purity by heating propyliodide with aluminium chloride in a sealed tube to 130. After subjection to this temperature for twenty hours the tube is allowed to cool and subsequently placed in a freezing mixture. (A. E. Tutton.) Lithium hydride is formed by raising metallic lithium to a red heat in an atmosphere of hydrogen. The gas is absorbed by the metal forming a white powder on which the atmosphere acts only very feebly. When wetted the powder restores the hydrogen it has absorbed and the quantity given off is greater weight for weight than is obtainable from any other material. Argon density equals 19*940 to 19 - 941. Argon viscosity equals 121. Air equals 100. Specific gravity of graphite equals 2-15 to 2-35. G.E. A A 354 GAS ENGINEER S POCKET-BOOK. Specific gravity of hydrogen gas equals '069. A column of any perfect gas expands from 1 to 1*3665 between C. and 100 G. One cubic foot hydrogen weighs 37 grains, therefore to obtain weight of 1 cubic foot in gas of any gas, multiply half molecular weight if a compound gas, or molecular weight if a simple gas X 37. The atomic weight of an elementary gas X '0691 equals its specific gravity. Half the atomic weight of a compound gas or vapour X '0691 equals its specific gravity. One litre H gas at C., and 760 millimetres pressure, weighs 0*0896 grains. H liquefies at about - 200 C. Specific gravity equals 1'1056, liquefies at -14 C., and a pressure of 320 atmospheres. To obtain weight in grains of any gas : specific gravity X 537 (weight of 1 cubic foot air) = grains per cubic foot. The correct temperature of the boiling point of propane is found to be - 37 at 760 millimetres pressure. (Tutton.) Ammonia density, '589 ; weight of 100 cubic inches is 18'26 grains. The hydrocarbons in unenriched coal gas, which give it its luminosity, are principally methane, ethylene, and benzene vapour. Usually accepted theory of light is, that there are three distinct zones ; the inner zone consisting of unburned gas. the middle lumin- ous zone, where the H changes into water, developing heat, and consequent incandescence of C, and the outer zone, where the C becomes carbon anhydride. Flame Temperatures. (Professor V. B. Lewes.) Inner zone temperature rises from a compar.itively low point at the mouth of the burner, to between 1,000 and 1,100 at the apex of the zone. Here takes place the conversion of the hydrocarbons into acetylene : the luminous zone, in which the temperature ranges from 1,100 to a little over 1,300, with a decomposition of the elements of the acetylene formed in the inner zone ; the extreme outer zone, in which the cooling and diluting influence of the entering air renders a thin layer non-luminous, and finally extinguishes it. Temperature of Different Portions of Flame in Different Oases. (Professor V. B. Lewes.) Acetylene. Ethylene. Coal Gas. Non-luminous zone - Commencement of luminosity . . Near top of luminous zone . Degrees C. 459 1,411 1,517 Degrees C. 952 1,340 1,865 Degrees C. 1,023 1,658 2,116 ILLUMINATING VALUES OF HYDROCARBONS. 355 Temperature of the mantle of a coal gas flame is above the melting point of platinum. (Smithells.) Hydrogen and CO only require half their volume of for complete combustion, and therefore obtaining this quickly, give only a short flame. Methane requires twice its volume of 0, and thus gives a flame nearly four times as long. A flame of a given size requires a volume of gas, larger or smaller, according to the illuminating power of the gas. The cause of luminosity in coal gas flames is not attributable to any one hydrocarbon, but to the combined action of all that are present in the gas. (Professor Lewes.) The illuminating property of gas depends upon the presence of about 4 per cent, of unsaturated hydrocarbons. Illuminating Value of Hydrocarbons per 5 Cubic Feet of Vapour. (Professor Lewes, 1890.) Methane . Ethane Propane . Ethylene Propene . Candles. 5-2 . 35-7 56-7 . 70-0 123-0 Acetylene , Benzene . Toluene Napthalene Candles. . 240-0 . 420-0 . 741-7 , 900-0 The illuminating value of hydrocarbon gas, when consumed alone, may be approximately calculated from the heat of formation or stored-up potential energy of the elements present in each hydro- carbon. Methane Ethane . Ethylene Acetylene . Illuminating Value. Calculated. 8-4 . 35-0 . 60-9 , 202-2 Found. 5-2 35-0 68-5 240-0 (Professor Lewes.) Illuminat- ing Power, 5 Cubic Oxygen required per Cubic Foot Con- Yield C0 2 . Water Vapour. Quantity Present in Coal Gas. sumed. Candles. Cubic Feet. Cubic Feet. Cubic Feet. Marsh gas . 5-2 2 1 2 40 to 50 per cent. Ethylene . 70 3 2 2 Benzene 420* 820f H 6 8 Acetylene . 400 2 2 1 Minute quantity. Frankland. f Knublauk. A A2 356 GAS ENGINEER'S POCKET-BOOK. Mr. W. Young has shown that where feebly luminous gas, which contains a large surplus of potential or heat energy, is carburetted, this heat energy is utilized in raising the potential of the added hydrocarbons, with a consequent increase of light. Table Showing the Comparative Quantities of Various Gases of Different Qualities Required to Evaporate an Equal Quantity of Water. (J. Travcrs.) Cannel gas Newcastle coal gas South Wales . of 24 candles . 22 . 20 . . 16-5 14-5 , 13-5 . 10-5 and 20 % cannel 14-0 18-50 cubic feet. 19-75 20-50 21-75 22-00 22-50 28-00 23-50 The Value of Coal Gas at Different Candle Powers for Lighting and Heating. (D. Wallace.) Candle Power of Gases. Comparative Specific Gravity. Value for Heating. Value for Lighting. 14-75 26-24 33-07 1-000 1-187 1-298 1-000 1-295 1-496 i-ooo 1-769 2-230 The products of combustion of gas are, H 2 0, caused by the com- bination of the hydrocarbons of the gas with the of the air, and C0 2 , from the combination of the C with the O of the air. The proportion of sulphur in the products of the combustion of coal gas, which is converted directly into sulphurous anhydride, ranges from 89 to 99 per cent. Cannel enriched London- 16-candle coal gas gives about a 3-inch flame in a " London " Argand burner. Carburetted water gas. 22-candle power, gives only about a 2-inch flame, owing to the presence of less methane. (Professor Lewes.) The quantity of air admitted to the flame is principally influenced by the pressure at which the gas issues from the orifice. 5 cubic feet of gas at ffihs pressure equals 11-14 candle power. 5 cubic feet of same at ^ths pressure equals 20 candle power, (Professor W. I. Macadam.) Size of flame from carburetted water gas is less than with coal gas for same illuminating power. (Professor Lewes.) Light moves with a velocity of about 180,000 miles per second. The mechanical equivalent of light equals 749 foot Ibs. per hour per candle. (Professor Julius Thomson.) Professor F. Clowes finds that an atmosphere of 16-4 per cent. C. 80-5 per cent. N, and 3'1 per cent. C0 a will extinguish a candle, but TEMPERATURES OP FLAMES. 357 can support a coal gas flame or life, whereas an atmosphere that will extinguish a coal gas flame will not support life. A paraffin flame will not burn in less than 16*6 per cent. O. A candle 15'7 , 0. A methane 15'6 AGO 13-35 A coal gas H'35 AH 5-5 O. 0. 0. 0. (Professor Clowes.) Temperature of a Bunsen Flame, Henry W. J. Waggener xound that the highest temperature he could get was 1,704 C. or 3,100 F., which is only a little below the melting point of platinum (1,780 C.). The Temperature of Bunsen Flame. (Professor Warburg.) The highest temperature found was 1,704 C. Strontium flame is rose coloured. Sodium flame is blue green. Mr. Macpherson showed (1878) that there was a proportionate relation between the hydrocarbons absorbed by bromine, the durability of a 5-inch flame, and the illuminating power ; and that the illuminating power and the durability bore a fixed relation to the percentage of C in the gas. Durability test is ascertaining the time that a cubic foot of gas will make a flame 5 inches high. With the durability test, and a jet of ^th inch diameter, and 5 inches flame, Dr. Fyfe found that the quantity consumed was directly as the square root of the pressure. In setting the jet photometer to work it should be calibrated by means of a Bunsen photometer, and with gases of different qualities. The water line in a jet photometer should be adjusted at least once a day by turning off the gas and letting out all pressure, and setting the hand at zero by adding more water as required. 8-8 inches IQ Mercury = 12 inches water pressure. One cubic inch of mercury weighs 0-49 Ibs. Mercury gauges are about 13 to 14 times shorter than water gauges. When the two tubes of a pressure gauge are unequal the quantity of liquid displaced in each tube is equal, and in inverse ratio to their sectional areas. Different sizes of tubes in U pressure gauges have no effect upon the correct registration of the gauge, the absolute difference of level being the same for a given pressure despite the inequality of the glasses. 358 GAS ENGINEER'S POCKET-BOOK. Photometers, &c. The Board of Trade Standards Department nas settled that the cubical contents of the photometrical room is not to be less than 1,000 cubic feet. This is best about 12 feet long by 9 feet wide by 10 feet high. This will take a photometer 100 inches or 60 inches long between the gas and candles. But if the room is larger it will be better for the purpose 1,500 or 2,000 feet cubic contents are not too much. Such ventilation is required that there shall be an ample air supply moving at a low velocity. Ventilation of the photometer room is a very important point. The air removed from a photometer room should be 2,000 to 3,000 cubic feet per hour. Mr. J. Methven found that air at increasing temperatures, saturated with moisture, decreased the light emitted from a flame rapidly equals 10 per cent, between 50 and 75 F. The area which the light covers equals 1 at 1 foot, but at 2 feet equals 4, at 3 equals 9, and at 4 equals 16. 4=16 I FT. 2 FT. 3 FT, 4 FT. With the shadow photometer, square the distances of the two sources of light from the screen, and divide the one into the other. It has been found that the normal eye can detect a difference in strength of light and shadow of fths. With a Rumford photometer the error in reading need not be more than J^th, and should not in usual cases be more than 1 per cent. On a 100-inch photometer bar the divisions are more easily read than on a 60-inch one. 60-inch bar in photometer is preferable to 100-inch for ordinary gases from 14 to 30 candle power, owing to the better illumination of the disc. If fog is present the 60-inch photometer bar is best, owing to the difference in value between the gas and caudles causing the CALIBRATING PHOTOMETER BARS. 359 greater obstruction on the one side. If the standard should be made more nearly equal this advantage of the 60-inch bar would disappear. Formula for calculating the comparative light of two sources : divide the distance of one from the screen by the distance of the other and square the quotient. To Graduate Photometer Bar. 100 */^"_l 100 inches. The distance from the candle to any marks= where a = the number to be placed upon the mark. 60 *T 60 inches. The distance from the candle to any mark = - 1 To Find the Distance of any Mark in a Photometer Bar from the Standard. Distance between lights X (\/ number of candles 1) Number of candles 1 = distance to mark. To prove this distance from mark to light 2 dis to ce & o mmark to standard* With a Fixed Distance for the Standard from Disc. \/ Number of candles X fixed distance = distance of mark from light. With a Fixed Distance for the Light to be Tested from the Disc. fixed distance - = distance from standard. \/Number of candles required The disc should be examined that it be not too dry or too old or have been badly made ; sometimes the two sides of a Bunsen disc will give a different reading, through the different temperatures to which the sides are subjected. The Gas Referees for London insist that 5 of the 10 tests shall be made with the one side of the disc to the gas, and the other five with the opposite side. After making 5 of the 10 tests reverse the disc, so as to equalize any difference in colour of the two sides of the disc. If the disc in a Bunsen photometer is made with 3 spots fixed horizontally and the disc placed slightly obliquely, the per cent, of error is considerably reduced in reading. (Mr. Heschus.) 360 GAS ENGINEER'S POCKET-BOOK. A chisel-shaped crayon has been used instead of a grease-spot paper in a photometer. The crayon is cut to a chisel edge and fixed with the edge in a vertical position ; the light falling upon it through two slits in a f-inch tube in the axis of which the crayon is fixed, when the lights are even the edge disappears, and the surface appears as aflat. A photometer has been made in which the decomposition by light of ioduret of nitrogen, prepared by the action of a pure aqueous solution of ammonia at 20 upon iodine, and noting the quantity of nitrogen produced in a given time, and the distance of the light from the liquid. (L6on.) For obtaining the illuminating power from the calorific value of a coal gas Mr. B. H. Thwaite recommends the following formula : photometric value in candles calorific value 2280 decimally graduated 352-6 the Berthelot-Mahler calorimeter being used. The candle balance should be sufficiently sensitive to weigh ^th grain. Photometers with sliding candles are not now stamped by the Standards Department of the Board of Trade. Standard candles should be 8f inches from base to shoulder and are made of spermaceti with from 4 to 5 per cent, beeswax. The Gas Referees Instructions allow the use of a candle burning within 5 per cent, of the prescribed amount. The chief error in the amount of light emitted by a candle is due to variations in the character of the wick employed. Variation in Light-giving Power due to Position of Wick. (J. Methven.) Plane of curvature of both wicks parallel to plane of disc equals 1-999 candles. Plane of curvature of both wicks at right angles to plane of disc and bent away from disc equals 1*957 candles. Plane of curvature of both wicks at right angles to plane of disc and bent towards disc equals 1-933 candles. The cone at the top end of sperm candles should not be used in photometry, but a good cup should be made under the wick by revolving the candle in the hand when lighted, allowing the grease to fall off, the extra length of wick should be removed. They should now be burnt until the wicks bend over, a red point is seen showing through the flame, which should be of its maximum size. No candles should be used that gutter badly, smoke, or form badly shaped " cups " around the wick, or have the wicks greatly out of the centre, or too closely or too tightly woven wicks. The candles should burn at least 10 minutes before commencing to test, and they should be placed that the plane of the wicks are at right angles to each other. PHOTOMETER CANDLES. 361 In testing gas the candles having been made in a mould are taper and should therefore be cut in half, and about half inch of the wax at the middle end removed from around the wick very carefully so that the latter is not damaged. All candles burning more than 126 grains or less than 114 grains per hour should be rejected. The spermaceti employed in the manufacture of standard candles is a mixture of solid fatty ethers and a small quantity of oil, with about 5 per cent, of beeswax to prevent crystallizing. Flames of Argand gas burners vary 8| per cent, in a range of 22 F. (J. Methven.) A comparison between different candles showed a maximum varia- tion of 22'7 per cent., and in one case the average of 10 experiments gave a difference of as much as 15 per cent. (Report of Committee on Photometrical Standards, 1881.) Candles which have been kept about 8 years show a reading about 8 per cent, higher than new candles will do. Professor Lewes considers the candles of the present day emit less light than those in use at the time the Act was passed prescribing the standard. At 50 F. the light from 120 grains of sperm equals T198 candles or + 20 per cent. At 72 F. the light from 120 grains ol sperm equals 1'041 candles or -f 4 per cent. Flames of candles vary 13 per cent, in a range of 22 F. The gas in the photometer is to be lighted at least 15 minutes before the testings begin, and is to be kept continuously burning from the beginning to the end of the tests. The candles are to be lighted at least 10 minutes before beginning each testing, so as to arrive at their normal rate of burning, which is shown when the wick is slightly bent and the tip glowing. To correct for any difference in the rate of burning of the candles average illuminating power x 600 actual time taken to burn 120 grains. 362 GAS ENGINEER'S POCKET-BOOK. Time taken to consume 10 grains. 9'34" 9'39", 9' 45" 9'si" 9's?" i's" lo'g" IO ' J 5" 93 1 937 94 2 948 954 * 106 1012 TO i io's8" 8" io'25" r 41 40 Grains sperm consumed 39 in ten minutes. CORRECTING FOR IRREGULAR BURNING OF CANDLES. 363 To obtain the Correction for the Irregular Burning of the Candles by the Diagram. Find by the sloping cross lines, the actual candle power, and immediately above the figure corresponding to the number of grains burnt in 10 minutes, or below the figure corresponding to the time taken to consume 40 grains, proceed horizontally, and note the figure above " 40 ; " this will give the candle-power corrected for the quantity of grains consumed. The service into the photometer room from the main ought to be of small diameter, and also be of lead lined with tin or a pure tin pipe laid inside an iron one to protect it. The reason for this is that a smooth polished surface does not present any hold for napthalene to attach itself to, and it can be readily washed out with hot water. A very important matter in relation to the supply of gas to a photometer is that the gas should come direct from the main and not through any meter before it gets to the photometer. An Argand burner is the only one which can be relied upon to maintain a steady, vertical light in a photometer, and to give fair comparative results should the quality of the gas vary a candle or so up and down. Equal areas of the flames of gases, with illuminating power from 12 to 60 candles, have equal illuminating powers. To correct for any difference in the rate of burning of the gas average illuminating power X 5 actual rate of burning. 364 GAS ENGINEER'S POCKET-BOOK. * rr> N w in tii i H EXPANSION OF GASES. 365 Diagram to find Corrected Candle-power of Gas according to Quantity burnt per hour. To Use the Diagram. Find the vertical line corresponding to the quantity of gas consumed in ten minutes, and the sloping curved line corresponding to the candle-power corrected from the point where these cross, proceed horizontally to the centre line, when the figures thereon will show the actual candle power corrected for the quantity of gas consumed. Boyle's or Mariotte's Law. The volume of a given mass of any gas varies inversely as the pressure, thus 1 volume gas at 4 pressures = 2 ,, , ,,2 = ^ 55 55 55 -* 5? therefore if a volume of gas is measured at any barometrical pressure the volume at 30 inches is 30 : observed pressure : : volume of gas : required volume. The corrected volume of gas + water vapour for both temperature and pressure equals observed volume X (observed pressure - tension of aqueous vapour at observed temperature X 17'64 observed temperature + 460. Gas expands ^ of its own volume for every 1 C. 5*3 1 F. (Charles's Law.) therefore, to correct any volume of gas measured at any temperature (F.) the volume at 60 F. equals (observed temperature) - 32 + 492) : (60 - 32 + 492) = 520 :: volume : required volume. 366 GAS ENGINEER'S POCKET-BOOK. To Use the Diagram. Find the horizontal line corresponding to the barometrical pressure, and the vertical line corresponding to the temperature of the room ; at the point where these two lines cross note the tabular number by the diagonal curved lines. Height of Barometer. 990 980 970 960 95 940 930 920 910 900 890 880 870 860 1030 I IO2O IOIO o 1000 990 8 980 ' 970 960 g 950 940 930 920 910 Height of Barometer. TABULAR NUMBERS. Height of Barometer. 367 1090 1080 1070 1060 j 990 980 970 960 3 5 Height of Barometer. j To correct for temperature and barometrical pressure, average illuminating power X 1,000 tabular number. The " London " Argand can be used for any quality of gas up to 18 candles ; and from 18 up to 25 candles the new Preston 18-candle standard " London " Argand may be used. The new proposal of the Standards of Light Committee is, that the rate of consumption of the gas shall be set to give a light equal to 16 candles, and the candle-power calculated from the time taken to consume th cubic foot (two revolutions of the test-meter drum). 368 GAS ENGINEERS POCKET-BOOK. 900 95 Tabular Numbers. looo 1050 900 950 IOOO Tabular Numbers. 1050 ii 1 100 HARCOURT'S 1 -CANDLE PENTANE UNIT. 369 To obtain the Correction for the Tabular Number by the Diagram. Note the tabular number, proceed up the line immediately above these figures until it cuts the sloping line corresponding to the candle- power found by the photometer, proceed horizontally, and note the figure above the 1,000 ; this will be the actual candle-power of the gas at 60 temperature and 30-inch barometrical pressure. Mr. Vernon Harcourt's 1-Candle Pentane Unit. The gas used for this standard is made by bringing together in a gasholder, air and the highly volatile liquid pentane, in the pro' portion of one cubic foot of air and three cubic inches of pentane. The pentane to be used is a mixture of pentane with some paraffins of lower and higher boiling-points, and is prepared by distilling the light petroleum at 60 C., at 55 0., and twice at 50 C. The pentane thus prepared must satisfy the following tests : On agitation with ^th of its bulk of fuming sulphuric acid for five minutes it must impart to the acid only a faint brown colour ; its liquid density must be between -62 and '63 at 62 F. ; the liquid must evaporate absolutely without residue at the ordinary temperature when the tension of its vapour is not less than 7'5 inches of mercury; the density of the vapour compared with air must not be less than 2 '4 7, nor greater than 2-53. The standard 1 -candle pentane unit burner consists of a brass tube 4 inches in length and 1 inch in diameter, which the gas enters towards the bottom. The upper end of the tube is closed by a brass plug \ inch in thickness, in the middle of which is a round hole \ inch in diameter. Around the burner is placed a glass cylinder, 6 inches by 2 inches, the top of which is level with that of the burner, air entering through the gallery on which the chimney stands. Above the burner is supported, at a height of 63'5 millimetres, a piece of platinum wire about 0'6 millimetres in diameter, and from 2 to 3 inches in length. The air gas passes through a small meter delivering at each revolution ^th of a cubic foot, and then through a small governor fitted to regulate the flow to 0'5 cubic foot an hour. The height of the flame is adjusted by means of a delicate stop-cock until the top of the flame appears to touch, but not to pass, the horizontal platinum wire which is adjusted so as to be exactly over the flame and to extend not less than half inch beyond it. A Sugg 16 candle Standard Burner gives only about 0'6 per cent, of the full mechanical equivalent, while a Welsbach incandescent burner only gives 1*4 per cent., while electricity only employs about the same per cent, of the original heat energy of the coal used for generating. (Dr. H. Morton.) The burner used for Dibdin's 10-candle pentane standard is a modification of Sugg's standard " London " Argand burner. The height of the screen in the 10-candle pentane standard should be 2-15 inches above the steatite. G.E. B B 370 GAS ENGINEER'S POCKET-BOOK. Herr Von Hefner-Alteneck's Standard of Light. The unit of light should be a free burning flame, in still pure air, supplied by a section of solid wick and fed with amyl-acetate ; the wick-tube to be circular and of German silver, measuring 8 millimetres internal diameter, 83 millimetres external diameter, 25 millimetres high. Flames to be 40 millimetres high, measured from the edge of the wick-tube at least 10 minutes after lighting the lamp. A variation of 0'02 is allowed in the light measurement. The German standard candle with a 45 millimetre flame Hefner unit English standard candle Hefner unit The amyl-acetate lamp, devised by Herr Hefner- Alteneck. is practically a spirit lamp burning the vapour of amyl-acetate. The wick is contained in a round tube of German silver, 8 millimetres in diameter and 25 millimetres high. It is formed of a strand of cotton yarns, and is so regulated as to produce a flame 40 millimetres in height. It is supposed to give a light equal to one candle, but Mr. Dibdin found that the height must be increased to 51 milli- metres to equal the light of one candle by the Methven standard. The Carcel (French photometrical standard) is now proved to be 10 candles (English standard) as against the hitherto variously estimated 9-2, or 9'5, or 9'8 candles. (Journal of Gas Lighting, July llth, 1893.) Messrs. Kirkham and Sugg found the carcel to equal 9'6 candles. Table Showing the Illuminating Power of Different Gases after Carburetting with Gasolene in the same Carburettor. (J. Methven.) Quality of Quality of Gas before Gas after Carburetting. Carburetting. 10-1 .... 73-98 average of 2 tests. 10-0 .... 71-18 2 16-0 . . . . 70-05 ., 3 22-0 .... 67-77 ., 2 27-5 .... 70-09 2 It will be noticed that the resulting quality of the gas is about equal in each case. Mr. Vernon Harcourt's 1-candle pentane unit burner consists of a brass tube 4 inches in length and 1 inch in diameter, the upper end of which is closed by a brass plug J inch in thickness, in the middle of .which is a round hole inch in diameter. A glass cylinder 6 inches long x 2 inches in diameter is placed with the top level with that of the burner, air entering at the bottom. A piece of platinum wire, DIBDIN'S IO-CANDLE PENTANE STANDARD. 371 about O6 millimetres diameter, is fixed at 63*5 millimetres above the burner. The air gas is delivered at the rate of about half a cubic foot per hour, and the flame is adjusted so that the tip just touches the platinum wire. The gas is a mixture of 1 cubic foot of air and 3 cubic inches of pentane. The pentane used is mixed with a distillation of the lighter petroleums at 60 C., at 55 C., and twice at 50 C., and must pass the following tests : It must be of '62 to -63 liquid density at 62 F., and when agitated with 5 per cent, by volume of fuming sulphuric acid for 5 minutes, must only turn the acid a faint brown colour. It must entirely evaporate at ordinary temperatures when its vapour tension is above 7-5 inches of mercury. Its vapour density must be between 2 - 47 and 2-53. In regulating the height of the flame the eye should be screened from the luminous portion of the flame. As long as the bottom of the carburettor is covered by the pentane it does not matter what depth of the liquid is present. With the 10-candle standard the light is constant between 42 and 73 F. Pentane, 1 volume, air 576 volumes, measured at 60 F. ; or as gases, 20 volumes of air to 7 of pontane gas. Pentane is a product of the distillation of petroleum spirit, having a specific gravity of '630 and can be made always exactly alike ; a certain quantity of pentane will be taken up by atmospheric air if allowed to pass over its surface. The pentane employed to produce the air gas used in Mr. Harcourt's 1-camlle standard and in the carburettor of the 10-candle pentane Argand was obtained by purifying light petroleum by the successive action of sulphuric acid and soda solution, and then distilling at 60 C., at 55 C., and twice at 50 C. Dibdin's Pentane Argand Burner Dimensions. Number of holes .... 42 Diameter 0'028 inches = 0-71 millimetres Inside diameter of steatite . . 0-390 = 9-9 Outside . . 0-750 = 19-05 Diameter of inside of metal cone at top 0-930 ,. == 23-62 Chimney length .... 6-000 ., =152-4 Chimney, inside diameter . . 1-5 !, = 33-1 Height of cut-off .... 2-15 .. = 54-61 ., The centre of the flainc should be immediately over the terminal of the photometer bar. Dibdin's 10-Candle Pentane Argand Air Gas Standard. The burner is a specially constructed tri-current Argand burner, the annular steatite ring being perforated with 42 holes, each hole being 0'71 millimetre in diameter. The inner perforated cone is punctured with ten apertures 0-25 inch in diameter. The dimensions of the chimney being 6 inches high and 1 inches inside, the top of the flame should be maintained as nearly as possible at three inches B B 2 372 GAS ENGINEER'S POCKET-BOOK. above the steatite. The middle portion of the screen is cut away so as to leave, above the top of the steatite burner, an opening 2*15 millimetres in height and 1*4 inches in width, the lower portion of this opening being exactly level with the top of the steatite. The carburettor for the 10-candle pentane Argand consists of a circular vessel constructed of tinned plate 203'2 millimetres (8 inches) in diameter and 50'8 millimetres (2 inches) in depth, having a spiral division 25'4 millimetres (1 inch) in width. This division is made by soldering in a spiral strip of metal 4 feet 6 inches in length and 2 inches wide, gas-tight to the under side of the top of the carburettor, so that when the top is fixed on, the bottom of the strip comes close to the bottom of the vessel and is sealed by the pentane, so that the air has to pass over pentane for a distance of about 4 feet 6 inches, and becomes thoroughly saturated. At the end of the spiral division, near the side of the carburettor, a bird fountain is fixed for charging the carburettor and keeping it charged at a constant level with liquid pentane. The lower end of the inlet fountain is closed, and rests upon the bottom of the tank. Through the side of the tube, which is 0*4 inch (10*1 millimetres) in diameter, 16 holes, 1 millimetre in diameter, are bored, close to the bottom, and through these the pentane enters the carburettor. At one side of the inlet-tube, 1 inch from the lower end, a small tube 3 millimetres in diameter and 20 millimetres in length is connected thereto and turned upwards. The fountain inlet-tube is carried up through the top of the carburettor, and continued in the form of a bulb having a capacity of about 200 cubic centimetres. When the carburettor is being charged the gas must be ex- tinguished, to avoid the risk of the vapour firing and causing an explosion. To Test Lime for its Purifying Value. Take a small quantity of lime, weigh and add sufficient water to slake ; dry and re-weigh, when increased weight shows quantity of water required to convert the caustic to hydrate ; then, as 56 parts caustic lime will absorb 18 parts water, the percentage of the former can easily be ascertained. To test if lime has been thoroughly burnt, add dilute hydrochloric acid, when no great effervescence should be given off. To Find the Quantity of C0 2 or H 2 S that a Sample of Lime will absorb per cent, pure lime 5 X - Tnf\ = number of cubic feet of COa or H 2 S absorbable. 1 Ib. pure Fe 2 8 will unite with 0*603 Ib. or 6'7 cubic feet H 2 S. Water will take up ^th of its weight of lime, and is then saturated. When limestone is burnt the C0 2 is expelled as per equation CaC0 8 = CaO + C0 2 . One part pure CaOH 2 O will unite with -594 parts C0 2 or -460 H 2 S or 1-lb. pure lime will unite with 5 cubic feet of either CO, or H 2 S. To Test Caustic Lime. Take a sample of known weight and thoroughly slake it, dry in an air bath at 250 F., and weigh ; the TO TEST OXIDE OF IRON. 373 increase of weight will indicate the quantity of water taken up in rendering the caustic lime into hydrate. Nine parts of water will be absorbed for every 28*5 grains caustic lime, then 28-5 x difference in weight g = quantity of caustic lime. If, however, any of the lime has absorbed moisture from the air, this will not show it. Hydrated peroxide of iron equals Fe 2 s , 3 H 2 0, which unites with 3 H 2 S to form 2 FeS + fi H 2 + S, and on revivification 2 FeS + 3 H 2 O + 30 equals Fe 2 3 , 3 H 2 O + 2S. Sulphate of iron equals FeO, S0 3 , which unites with H 2 S and NH 3 to form FeS + NH 4 0, S0 3 . Lime equals CaO, which unites with the equivalent of H 2 to form CaOH 2 0, equals hydrate of lime, which combines with C0 2 to form CaOC0 2 + H ? 0, or with H 2 S to form CaS + 2H 2 0. When lime which has taken up H 2 S and become CaS + H 2 is presented to C0 2 it becomes CaOC0 2 -f- H 2 S, the H 2 S being driven off, owing to the greater affinity of CaO for C0 2 . Sulphide of lime (CaS) combines with CS 2 to form CaS, CS 2 equals sulphocarbonate of lime, which requires a longer contact for combination than is necessary with H 2 S or C0 2 . Hydrochloric acid will dissolve hydrated ferric oxide, but has little effect on anhydrous ferric oxide. To Test Spent Oxide of Iron, Lime, or Weldon Mud for Sulphur. Dry the sample at 212 F. until a constant weight is obtained, then place in a test tube with a little cotton wool at the bottom, pass a quantity of CS 2 (about three or four times the bulk of the oxide) through it, and allow the solution to fall into a flask, evaporate the CS 2 with heat, when the S will remain in the flask and the quantity can be easily found. Mr. A. J. Bale proposed to so arrange the apparatus for testing spent oxide for sulphur that the bisulphide of carbon is evaporated and condensed, and then to pass through the oxide to the evaporating flask to again go through the cycle until all the sulphur has been removed from the oxide, and by this means reduce the quantity of bisulphide necessary. When testing oxide by the bisulphide method, care should be taken that the oxide has been thoroughly revivified. Place dilute hydrochloric acid in a wide-mouthed bottle and stand in this a small vessel containing the spent oxide, connect to measuring tube immersed in water, overturn the oxide into the acid, when the quantity of H 2 S driven off will be found by the displacement of the water in the measuring tube. Twenty-five grammes spent oxide is the best amount, and, when fresh from the purifier, will evolve about 250 cubic centimetres of H 2 S. Four days will usually suffice to revivify oxide. Temperature of oxide while revivifying, and in presence of ample moisture, may reach 140 to 160 F. One ton of good oxide should purify 1 to 1 millions cubic feet before becoming spent. 374 GAS ENGINEER'S POCKET-BOOK. Volumes. 78,000 3,300 253 100 Volumes. Oxygen .... 3-7 CO 1-56 N 1-56 H 1-50 12'5 Light carburetted hydrogen 1 -(50 (Dr. Frankland.) Beckton Purifying Method. 2 carbonate vessels for the elimination of C0 2 2 oxide H 2 S 2 sulphide CS 2 etc. 2 weldon mud H 2 S driven off from sulphide vessels. 100 Volumes Water at 60 F. and 30 Inches Barometer will absorb Ammonia . Sulphurous acid H 2 S . C0 2 Olefiant gas One volume H 2 at C. dissolves 4-37 volumes H 2 S. H 2 S unites with an equal weight of NH 3 . 22 parts C0 2 unite with 17 parts NH 8 . Quantities of Gases Absorbed by Water at 20 C. at 760 Millimetres Pressure. Hydrogen . . 1-9 per cent, of the volume of water. N . . . . 1-4 O 2-9 Methane . . 3-5 GO . 2-3 C0 2 . . . 90-0 Ethylene . . 15-0 Acetylene . . 95'0 H 2 S' . . . 291-0 NH 8 . . . 74,000-0 To Find the Amount of C0. 2 in Gas Liquor. Add an excess of barium chloride to a known quantity of gas liquor, digest for 30 minutes at a gentle heat, filter, then dry, ignite, and weigh the precipitate. Every 98'5 parts of barium carbonate contains 22 parts C0 2 . To Estimat: the Quantity of Free Ammonia in Liquor. Take a glass measure graduated into 16 parts, fill with liquor and empty into a glass beaker, rinse the measure with distilled water and add rinsings to liquor in beaker with a few drops of methyl orange indicator. Kinse the measure with a little 10 per cent, acid solution and throw away rinsings, fill up measure with 10 per cent, acid solu- tion (specific gravity, 1,064-4 at 60 F.), and pour acid very gradually into beaker until the liquor is neutralized. The number of divisions of acid solution used equals ounces strength of liquor. To Estimate the Quantity of Ammonia in Liquor. Mix a known quantity of the liquor with an excess of caustic lime or soda, heat, and lead the evolved fumes of ammonia through a solu- 10 PER CENT. ACID SOLUTION. 375 tion of sulphuric acid (10 per cent.) until all the gases of ammonia are evolved, titrate the acid solution, with 10 per cent, alkaline solu- tion, note quantity of latter necessary to neutralize, deduct from quantity of acid solution used, equals strength of ammonia in liquor. Ounces strength of ammoniacal liquor is the number of ounces by weight of H 2 S0 4 (specific gravity 1,064-40 at 60) required to neutra- lize a gallon of the liquor. To convert degrees Twaddell to specific gravity (water equals 1 ) (Degrees x '005) + 1. To convert specific gravity into degrees Twaddell Deduct 1 and divide by -005. Every ounce strength of ammoniacal liquor equals '347 ounces of absolute ammonia. Specific Gravity of 10 per cent. Acid Solution at Various Temperatures. (L. T. Wright.) Temperature. Specific Gravity. Temperature. Specific Gravity. Temperature. Specific Gravity. F. c. F. C. F. C. 40 4-45 1068-10 54 12-23 1065-64 68 20-00 1062-72 41 5-00 1067-94 55 12-78 1065-45 69 20-56 1062-51 42 5-56 1067-78 56 13-34 1065-24 70 21-11 1062-30 43 6-11 1067-62 57 13-90 1065-03 71 21-67 1062-08 44 6-67 1067-46 58 14-45 1064-82 72 22-23 1061-86 45 7-23 1067-30 59 15-00 1064-61 73 22-78 1061-64 46 7-78 1067-12 60 15-56 1064-40 74 23-34 1061-42 47 8-34 1066-94 61 16-11 1064-19 75 23-90 1061-20 48 8-89 1066-76 62 16-67 1063-98 76 24-45 1060-97 49 9-45 1066-58 63 17-23 1063-77 77 25-00 1060-74 50 10-00 1066-40 64 17-78 1063-56 78 25-56 1060-51 51 10-56 1066-21 65 18-34 1063-35 79 26-12 1060-28 52 11-11 1066-02 66 18-89 1063-14 80 26-67 1060-05 58 11-67 1065-83 67 19-45 1062-93 85 29-45 1058-95 Test for Sulphuretted Hydrogen. The gas is dried and passed through U tubes containing cupric phosphate on one side and non-alkaline calcium chloride on the other, the difference in weight of the U tube giving the quantity of sulphuretted hydrogen in the amount of gas passed. (L. T. Wright.) Another Test for Sulphuretted Hydrogen. The gas is made to bubble through an acid solution of cadmium chloride in two or three Woulffe's bottles, when cadmium sulphide is precipitated, which may be washed, filtered and weighed, and the quantity of H 2 S thus obtained. Sheard's Test for Ammonia, H 2 S and C0 2 in Gas. Four absorption tubes are required and a filter tube containing cotton wool to absorb tarry matters when testing crude gas. In the 376 GAS ENGINEER'S POCKET-BOOK. first tube a certain quantity of half deci-normal strength sulphuric acid is placed; in the second a quantity of cupric sulphate 1 part and water 10 parts (30 cubic centimetres of this should absorb all the H 2 S from 500 cubic centimetres crude gas) ; in the third and fourth tubes, say, 30 cubic centimetres and 20 cubic centimetres of barium hydrate. The first tube is the test for NH 3 , the second for H S, and the other two for C0 2 . Pass, say, 500 cubic centimetres of sjas slowly through the apparatus, and then 1 ,000 cubic centimetres of air to ensure that the whole of the gas has passed over the whole of the apparatus. Wash out the glass scrubber of each absorption tube with a little distilled water. Titrate the contents of the first tube with -^Q ammonia HO, using cochineal as an indicator, note the quantity required to neutralize, and deduct this from the quantity of sulphuric acid placed in the tube X 74 = grains of ammonia per 100 cubic feet gas. Titrate the second tube with similar ammonia solution, and use methyl orange as indicator X 74 = grains H 2 S per 100 cubic feet gas. (Each cubic centimetre ^ acid = 74 grains NH 3 per 100 cubic feet of gas. Each cubic centimetre ammonia re- quired to neutralize = 74 grains H 2 S per 100 cubic feet gas.) Titrate the washings of the third and fourth tubes with HC1, deduct the quantity required to neutralize from equivalent of Ba HO, first put in tube X 0'24 = volumes per cent, of C0 a . Harcourt's Colour Test for H 2 S. Here the gas is passed straight through the acetate of lead solution until the correct colour is obtained, when the quantity of gas passed contains 0-0025 grains S, and as S exists in H 2 S in the proportion of 32 to 2 H by weight, the quantity of H 2 S can'be readily found. Harcourt's Colour Test for CS 2 . The gas containing CS 2 is made to pass over heated platinised pumice, when the equivalent amount of H 2 S is formed and made to bubble through a solution of acetate of lead until the latter is turned to a brown shade of a certain tint, when the quantity of gas passed over the pumice is noted, and to effect this an amount of H 2 S equal to 0*0025 grains S must have been in the gas, from which the quantity per 100 cubic feet may be ascertained. 7 or 8 grains per 100 cubic feet should be added to the quantity found by above test for other sulphur compounds not acted upon by above method. If the gas is not already freed from H a S it must be passed through an oxide purifier before being allowed to grt to the pumice. A diagram to facilitate the calculation of S from the divisions of the measuring cylinder commonly used, which latter equal cubic feet is shown. HARCOURT'S COLOUR TEST. Diagram for use with Harcourt's Colour Test. 500 Grains of Sulphur = D ivisioris of Measuring Cylinder. 140 130 378 GAS ENGINEER'S POCKET-BOOK. To Test for Presence of Acetylene. Bring the gas into contact with ammoniacal cuprous chloride solution when red acetylide of copper is formed ; aspirate the gas into a flask containing the blue cuprous chloride, agitate, and, if acetylene is present, the sides are at once coated with the red compound. The gas is bubbled through a small orifice under lime water, made by mixing slaked lime and water and decanting the clear liquid when time has been allowed for the mixture to settle. If C0 a is present in the gas the lime water becomes milky. Charge two absorption tubes with 20 or 30 cubic centimetres each deci-normal barium hydrate solution ; pass 500 cubic centimetres of gas through, then immediately 500 cubic centimetres air. Wash out the absorption tubes, add a few drops phenol-phthalein and titrate with deci-normal hydrochloric acid. Deduct quantity of acid re- quired to neutralize from equivalent of barium hydrate used equals amount of C0 2 absorbed from 500 cubic centimetres of gas X 0-241 = per cent, by volume X 1'92 = grains per cubic foot 0-0022 gramme C0 2 is equivalent to 1 cubic centimetre of deci- normal acid. 0'914 gramme equals weight of 500 cubic centimetres of C0 a saturated with moisture. 28,315 cubic centimetres equals value of 1 cubic foot. 15,432 grns. equals value of 1 gramme. To Detect Oxygen or Air in Coal Gas. Fill a graduated glass with gas and then bring in contact with a solution of pyrogallic acid, made alkaline with caustic potash ; when oxygen is absorbed, the rise of the acid in the graduated tube showing the quantity of oxygen absorbed from the gas, this quantity X 5 equals quantity of air. The quantity of oxygen is usually obtained by subtracting the weight of all the other constituents from the original weight of the substance being analysed. To Convert Percentage of C0 and H.,S into Cubic Inches per Gallon. . for H a Methods of obtaining Specific Gravity of Gases. Direct Method. Weigh a hollow vessel, in an exhausted state, then filled with air, and afterwards, when filled with the gas under test, weight of air ^ weight of gas equals specific gravity. SPECIFIC GRAVITY OF GASES. 379 Aerostatic Method. A balloon of. say, 1 cubic foot capacity is filled with the gas and the balloon weighted until it is just prevented rising in the air. Weight of air displaced by balloon - weight of balloon when weighted equals weight of gas ; then weight of air dis- placed ~ weight of gas equals specific gravity. Effusion Method. If any gases are expelled at same pressure through a small aperture in walls of minute thickness the squares of the velocity of expulsion are in inverse ratio to the specific gravity of the gases. Liquid Balance Method. If the lower end of a tube of some length be immersed in liquid the height of the liquid in the tube will vary according to the specific gravity of the "gas in the tube. Hydrometer Method. Place a hydrometer, with a hollow glass ball, hermetically sealed at top, into a glass cylinder partly filled with water, and cover all with a further glass bell and pass gas through the latter so that hydrometer ball is surrounded by the gas, when the hydrometer will rise and fall according to the specific gravity of the gas. Lux's Gas Balance Method. Pass air through the globe and note the position of pointer, and move scale to equal I'OO, then pass gas through and note the position of pointer, and the figure against same at pointer equals specific gravity of gas. The sensitiveness of the apparatus can be increased by, or diminished by, raising or lowering the centre of gravity of the balance from the centre of motion. To Determine the Specific Gravity of a Gas. (Greville Williams.) Pass air through one bottle potassium hydrate solution, two bottles sulphuric acid, 6 U-tubes of very active soda-lime, and 4 U-tubes of calcic chloride, and then through a glass globe with stop-cock at each side, and after passing through the globe through one more tube of calcic chloride. The air should be drawn through by an aspirator until the weight becomes constant and temperature regular. Shut tap of globe on aspirator side and remove rubber connection on that side and then close the other tap. Wipe the globe with a silk hand- kerchief and hang by platinum wire to one side of a balance. Counterpoise with globe of a little smaller capacity, using weights to exactly balance. Note these weights required and call weight of balloon and air. Pass the gas to be tested slowly through 6 U-tubes of soda-lime to remove all trace of C0 2 , and through 4 tubes of calcic chloride for one hour, then through the globe with a further tube of calcic chloride on outlet. Shut off the inlet tap and then immediately the outer tap. Fix and weigh as before equal to weight of balloon and gas. Specific gravity of the gas equals capacity of balloon or globe in cubic centimetres multiplied by weight of 1 cubic centimetre air at the temperature in C. of the test, less the difference in weight of the balloon divided by the capacity of the balloon multiplied by weight of 1 cubic centimetre air, 380 GAS ENGINEER'S POCKET-BOOK. To Obtain the Specific Gravity of any Coal. Weigh a small piece in and out of distilled water (02 F.) then Weight in air _ g . fi ' loss of weight when weighed in water Specific gravity of any substance X 1,000 equals weight in ounces (avoirdupois) per cubic foot. To Obtain Value of Gas in Grains Sperm per Cubic Foot. Illuminating power X 120 To Obtain Value of Coal per Ton in Ibs. Sperm. Value in grains sperm per cubic foot x cubic feet made per ton 7,000 or, Cubic feet made per ton g - X illuminating power X 3 175 Average Analysis of Bituminous Coal. Caking. Non-caking. Specific gravity . . . 1-267 1-279 C 80-05 77-19 H 5-92 5-2G O . . ' . . . . 8-98 12-01 N 2-21 1-89 S 1-13 -64 Ash 1-72 3-02 Determination of the Caking of Coal. (Louis Campredon.) The coal is powdered to pass through a sieve of 2.580 meshes per square inch, and a fixed quantity say 1 gramme of it is mixed with various amounts of uniformly fine sand. Each sample of coal and sand is heated to redness in a small porcelain crucible, and the character of the residue is observed when cool. From the various samples, the maximum quantity of sand which may be added to the given weight of coal with the production of a firm cake on heating is found. The weight of coal is t:;ken as unity in the scale of comparison ; and the caking power of coal which leaves a powdery residue is of course nil. The highest result found with any coal was 17 on this scale ; pitch gave 20. The illuminating power of 140 samples of caking coal varied from 12-5 to 18-5 candles, and the quantity purified by 1 cwt. lime varied from 10,000 to 18,000 cubic feet. TESTS OF COAL. 381 Table Showing the Changes Wood Undergoes in Becoming Coal. (Roscoe and Schovlcmmer.) C. H. O and N. Wood 50-00 6-00 44-00 Irish peat 60-02 5-88 34-10 Lignite from Cologne 66-96 5-25 27-76 Earthy coal from Da,x . . 74-20 5-89 19-90 Canncl coal from Wigan. 85-81 5-85 8-34 Newcastle Hartley . . . 88-42 5-61 5-97 Welsh anthracite . 94-05 3-38 2-57 Graphite 100-00 o-oo o-oo Average Analysis of Welsh Anthracite. (J. Hornby.) Per Cent. Fixed carbon 89'84 Ash 1-20 Sulphur 0-80 Moisture 2'25 Volatile matter 6'01 Lignite specific g'ravity equals 1*15 to 1'3. Bituminous coal, specific gravity equals 1-25. Tests of Coal. Dry coal at 100 C., weigh every 2 hours, and note lowest weight to obtain amount of moisture. To obtain quantity of coke or volatile matter, weigh coal in platinum crucible, burn off over powerful Bunsen flame until all gas is driven off, allow to cool in dessicator and weigh ; residue = coke. Original weight - coke = gases. To estimate quantity of asb, weigh coal in a platinum boat and heat it in a glass tube to red heat, air being slowly drawn through the glass tube ; cool and weigh boat. To find total quantity of sulphur, weigh coal with four times its weight of sodium and potassium carbonates mixed in molecular pro- portions in platinum crucible. Heat over Argand spirit lamp, and slowly increase to just below visible redness until coal becomes faintly grey, then raise heat to a faint red for 40 to 60 minutes ; cool. Products of Distillation of 1 Ton Newcastle Coal. Temperature of Distillation, 1,000 to 1,200 F. Gas . . 7,450 cubic feet. Tar ... 18J gallons. Coke . 1,200 Ibs. (Gesner.) Products of the Tar. Benzol . . 3 pints. Coal tar naphtha . . 3 gallons. Heavy oil and naph- thalene . . .9 . Temperature of Distillation, 750 to 800 F. Gas . . 1,400 cubic feet Crude oil . . 68 gallons. Coke . . 1,280 Ibs. Products of the Crude Oil. Eupion . . .2 gallons. Lamp oil . . . 22 Heavy oil and paraffin . . 24 ., 382 GAS ENGINEERS POCKET-BOOK. Composition of Fuels (Ash being Deducted). (Sir H. Roscoe.) Description of Fuel. Percentage Composition. C. H. N and O. 1. Woody fibre 2. Peat from the Shannon . . 3. Lignite from Cologne . . . 4. Earthy coal from Dax . 5. Wigan cannel 6. Newcastle Hartley 7. Welsh anthracite .... 52-65 60-02 66-96 * 74-20 85-81 88-42 94-05 5-25 5-88 5-24 5-89 5-85 5-61 3-38 42-10 34-10 27-76 19-90 8-34 5-97 2-57 The above shows the alteration in composition which wood has undergone in passing into coal. Average carbon in average gas coke equals 88 per cent. Average carbon in average anthracite equals 90 per cent. The in purified coal gas does not result from the distillation of the coal, but must have been admitted with the air either inten- tionally or accidentally. Gas only forms about 15 per cent, of the total products obtained from the distillation of coal. Experiments on small quantities of coal usually give results 7 per cent, in favour of the coal over working results. Sulphur in Coal. (J. Hepworth.) Sulphur in Volatile Products per Ton of Coal. Sulphur in Coke per Ton of Coal. Total Quantity of Sulphur per Ton of Coal. 'eS O O Q A B C D E F Lbs. 4-35 7-84 4-70 18-16 9-18 9-04 Percentage. 19 35 21 81 41 44 Lbs. 8-51 4-92 7-61 15-0 6-04 7-76 Percentage. 38 21 34 67 27 31 Lbs. 12-86 12-76 12-31 33-16 15-22 16-80 Percentage. 57 56 55 48 68 75 Average sulphur Left in coke Removed by p Coal per ton of coal, 13-80 Ibs. . . 6-53 Ibs urification from volatile products . 7*27 ...... . 13-80 s coals contain sulphur, principally combined with iron, of bisulphide of iron (FeS 2 ) or pyrites which become Bituminous in the form sulphide or protosulptiuret of iron (FeS) on the application of heat. Coal gas contains about 7 per cent. CO. * According to the Gas Referee's Reports gas always contains about 10 grains sulphur per 100 cubic feet when sent out. The whole of the sulphur in coal gas is converted into sulphur dioxide during combustion. (W. C. Young.) GRAINS OF BARIUMSULPHATE CORRECTED. 383 Diagram showing Grains of Sulphur per 109 Cubic Feet for each Grain of Barium Sulphate (corrected for Temperature and Pressure) . Tabular Numbers. 1040 IO2O IOOO 980 960 940 920 900 451 35 8 I 5 g O 384 GAS ENGINEER'S POCKET-BOOK. To Estimate Lbs. of Prussian Blue in Gallons of Cyanogen Liquor. Filter small quantity of liquor, take 5 cubic centimetres, acidify with dilute HC1 (1 part HC1, H H 2 0), precipitate the Prussian blue with a slight excess of Fe 2 Cl 6 (ferric chloride) solution. Collect precipitate on tilter, wash till free from acid, and dry at 100 C. Wash the dried precipitate with previously dried CS 2 (that is CS 2 not in contact with water) and allow to stand until the CS 2 has drained off or evaporated, and return it to drying oven until quite dry ; cool and weigh. Weight in gas X 2 = pounds per gallon. Per cent, of HCNS 2-62, NH 3 1-87, K 4 FeCy 6 + 3aq 5'10, from analysis of twelve samples of spent oxides in Germany. (J. V. Esop.) Some of the N in the coal combines with two equivalents of carbon to form cyanogen, which unites with sulphide of ammonium to form sulphocyanide of ammonium. If spent oxide be burned for making H 2 S0 4 the cyanogen com- pounds cannot be recovered. Spent oxide has been found to contain, with 25 per cent, sulphur, 12J per cent. Prussian blue. ENRICHING PROCESSES. 385 ENRICHING PROCESSES. Relative Cost of Enrichment from 16 Candles to 17-5. (Professor Lewes, 1891.) By Cannel (Livesey) 4'OOd. = 2-667^. per candle per 1,000 cubic feet Pintsch gas . . 3 64 = 2-427 Oil gas (Foulis) . 2-34 = 1-560 ., ., Maxim- Clark pro- cess . . . 1-64 = 1-093 ., Carburetted water gas . . . 1-01 =0-673 ., .. Tatham Oxy -oil process (probable) 0'91 = 0-607 Tatham Oxy -oil process (claimed) 0'50 = 0-333 Peebles process said to give 1,750 candles per gallon. Water gas process said to give 1,400 candles per gallon. Carburine, gasoline and benzol said to give 1,600 candles per gallon. Pintsch gas, liquid from compression, said to give 3,000 candles per gallon. Gas enriched 1 Candle by 1 Gallon of the Liquid. Benzol (chemically pure) .... 13,300 cubic feet. Benzol (90 per cent.) 12,500 Carburine (specific gravity '680) . . . 5,700 Common petroleum spirit (specific gravity -700) 4,300 (T. Stenhouse.) With 5 per cent, petroleum vapour there is no danger of explosion ; with 6-25 per cent, a feeble report; with 8-30 per cent, a loud report ; with 11 to 14 per cent, a violent report ; with 20 per cent, no explosion. (Journal of Gas Lighting.') 70 per cent, by bulk of producer gas lowers the flame temperature of water gas 400. (Walter Clark.) The lower the gas in illuminating power the more it costs to improve it. Mr. Foulis considers undiluted oil gas is better for enrichment and more economical than carburetted water gas. In distilling shale oil the gas has to be rapidly drawn off, or it would become permanent. Oxygen (up to \ per cent.) added to pure gas increases the illu- minating power (see Gas Journal, 1885, " Midland Association "). (B. W. Smith.) Formula to find Proportion of Enriching Gas Required. Initial candle-power co candle-power desired ~ Initial candle-power oo candle-power of enriching gas = percentage required. a.E. o o 386 GAS ENGINEER 8 POCKET-BOOK. Formula to find Quantity in Cubic Feet to be added to Initial 1,000 Cubic Feet. 1,000 ~ Initial candle-power candle-power desired Candle-power of enriching gas candle-power desired = quantity in cubic feet per 1,000. If gallons carburine (specific gravity 68) per 10,000 cubic feet gas required to enrich 1 candle by Clark carburettors. Enriching Value of Oil Gas due to Temperature of Distillation. (W. Foulis.) Coal Gas. Illuminating Power, cor- rected to 5 Cubic Feet per Hour. Oil Gas. Illuminating Power, cor- rected to 5 Cubic Feet per Hour. Percentage of Oil Gas added. Illuminating Power of combined Gas corrected to 5 Cubic Feet per Hour. Enrichment Value of Oil Gas calcu- lated to 5 Cubic Feet. Average Retort Tempera- ture. 20-74 20-45 18-51 16-84 14-65 64-05 60-88 62-11 61-10 74-00 4-20 4-90 4-52 4-38 4-00 24-28 23-69 21-59 20-85 19-77 105-20 86-60 86-60 108-30 117-00 1.100 V. 1,135 F. 1.145 F. 1,070 F. 1,000 F. Gasoline boils at about 40 C. Carburine boils at about 67 C. Specific gravity 0-680. Benzene boils at about 80-5 C. Specific gravity 0-885 at 15 C. Kussian mineral oil ('908 specific gravity) contains 20'5 grains sulphur per gallon. Russian burning mineral oil contains 10*3 grains sulphur per gallon. American 16*3 ,, American water white mineral oil contains 8'1 grains sulphur per gallon. American burning safety mineral oil contains 14*0 grains sulphur per gallon. Scotch mineral oil (for gas making) contains 49'S grains sulphur per gallon. (W. Fox and D. G. Riddick.) Petroleum contains about 85 per cent. C, 13 per cent. H, 2 per cent. ; specific gravity '87 ; weight 8'7 Ibs. per gallon. Petroleum oil contains about 73 per cent. C, 27 per cent. H ; specific gravity '71 ; weight 7*10 Ibs. per gallon. 162 cubic feet of 16-candle gas will retain the vapour from 1 gallon carburine at 59 F., and 30 inches pressure. (Professor W. Foster.) Where cannel is used for enrichment there is seldom much napthalene deposited. To produce gas from iron and steam, for every 1,000 cubic feet hydrogen produced, rather less than 1 cwt. iron would be required, (H. Kendrick.) BENZOL AS AN ENHICHEH. 387 The "Browne" Process of Making, Lighting, and Heating Gas from Crude Petroleum. An emulsion of 5 or 6 volumes of crude petroleum is made with 95 or 94 volumes of water. This emulsion is pumped slowly through a tube about 300 feet long under a pressure of 100 Ibs, on the square inch. One end of the tube is at the temperature of the air, the other is sufficiently hot to bring about chemical action between the vaporised contents, and hydrogen and carbon monoxide are liberated as permanent gases that are then passed through a coke-water scrubber and may afterwards be stored in a holder for use. The heat applied to the converting tube increases gradually from end to end. The light-giving value of the gas can be raised by allowing a greater proportion of petroleum to be added when about half-way through the converting tube. Mixtures of ethylene and oxygen in insufficient quantity to form explosive mixtures possess greater illuminating power than pure ethylene, the highest luminosity observed being with 75 per cent, ethylene and 25 per cent, oxygen. An increase of oxygen above this diminished the illuminating power. Wood Gas. One retort about 21 inches diameter by 9 feet 6 inches long will produce 12,000 cubic feet per day. One ton of wood will produce 8.000 to 11,000 cubic feet, of 9 to 16- candle gas. Eesiduals, charcoal 4 cwt., tar 1^ cwt. Benzene is as 500 to 900 candles per 5 cubic feet vapour, compared with napthalene. (Professor V. B. Lewes.) Benzene is probably not efficient when the gas requires enriching more than 1 to 2 candles. Benzene vapour should have an illuminating power of 700 candles per 5 cubic feet, with an enriching value of 3*9. (Professor V. B. Lewes.) A gallon of benzol has an enrichment value of only 4,500 candles, and carburine is only one-fourth as effective. (Mr. W. Young, of Peebles.) One gallon of benzol will enrich from 12,000 to 15,000 cubic feet, adding 1 candle-power to it. The cost to enrich 1,000 cubic feet to the extent of 1 candle-power with benzol is from %d. to Id. Four to 5 candles can be added to gas with 600 to 700 grammes benzol, and would be stable at 32 F. At 77 F. gas will hold four times the quantity of benzol which it will at 30 F. (Dr. Schilling.) Temperature required to vaporise benzol = -f- 212 F. It is unnecessary to heat benzol when using it as an enricher, except in very cold weather. The molecular structure of the benzol molecule is such that, of all the liquid hydrocarbons known, it is the one which may be expected to break up most readily.into that wonderful acetylene, which, according to some authorities, puts everything into the shade as a light pro- ducer. (T. Steiihouse.) Vapour tension of benzene (90 benzol) at 59 F. equals 58'9 milli- metres. 002 388 GAS ENGINEER'S POCKET-BOOK. 1,000 parts of water dissolve 1*45 parts of benzene, 0*57 parts of toluene, and 0*12 part of xylene. Benzene can be obtained by keeping acetylene for a long time just below a red heat. (Professor Mills.) From Manchester gas 3 '7 to 4-25 gallons of liquid per 10,000 cubic feet were dissolved out, containing 80 per cent, hydrocarbons of the benzene series (1884), with an enrichment value of 4,500 candles per gallon. (Gr. E. Davis.) At least three times the amount of petroleum spirit is required to repair the loss of a certain quantity of benzene, and there is also a great difficulty in getting the required amount into the gas without condensation. (Wilfred Irwin.) One cubic foot gas will permanently retain alone 50 grains benzol vapour at a temperature of 32 F. (T. Stenhouse.) Average Specific Gravities of Commercial Benzols. 90 per cent, benzol .... 0*880 to 0-883 50 Solvent Naphtha 90 per cent, at 160 C. Heavy naphtha . Pure benzene . Toluene Xylene 170 C. 0-875 to 0-877 0-870 to 0-872 0-874 to 0-880 0-890 to 0-910 0-920 to 0-945 0-883 to 0-885 0-870 to 0-871 0-867 to 0-869 One candle enrichment per gallon with benzol. C. Hunt gives .... 9500 cubic feet. Schilling ., . . . . 15600 J. F. Bell '.... 20000 Dr. H. Bunte .... 24500 One cubic foot benzol equals 40 candles (L. T. Wright). ,, 147 (Professor Falkland). ,, ,,184 (Knublauch). The higher the percentage of methane the greater the power of absorbing benzol. Benzene freezes at 32 F.,-and boils at 177 F. ; specific gravity at 60 F. 0-8833. Each grain absorbed per cubic foot of common gas increases illuminating power 10 per cent. (Letheby.) Enrichment per Gallon per 10,000 Cubic Feet with Benzene. Candles Enrichment. Bunte gives 3-6 Frankland 2-9 Hunt . . . - - 0-9 Knublauch JJ Stenhouse 1*3 L.T.Wright .... -0-8 W. Irwin ., with flat flame burner Argand . . 0'5 BENZOL AS AN ENRTCHER. 389 To enrich with benzol, the coal gas is made to pass over the surface of cold benzol, and the vapour rising from this is taken up and com- bines with the gas at once, the quantity absorbed being regulated by the area of benzol surface exposed and the rate at which the gas passes through the benzoliser. Gas enriched to 17 or 18 candles with benzene would be far better appreciated by the average consumer than 20-candle gas owing its illuminating power largely to olefines. Benzol will separate when the gas is exposed to great cold. (Dr. Buel.) Commercial benzol if used for enrichment may contain sufficient sulphur to cause an increase of 10 grains S per 100 cubic feet of gas per 1 candle of enrichment. Ninety per cent, benzol contains 25 per cent, toluol, therefore it is best to use the purest benzol for enriching, as the evaporation is not so rapid with toluol, nor the enriching value so great. The higher the boiling-point of the paraffin series of hydrocarbons the greater is their enriching value. (Wilfrid Irwin.) While for carburetting feebly illuminating coal gas about 8-8 grains of benzol or toluol, or 31-7 grains of pentane or hexane per candle per hour are required, with hydrogen double the quantity is required, and with carbonic oxide treble is required. (Dr. H. Bunte.) Candle Cubic Enrich- Feet of ment. Gas. 1 gallon pure benzol = 1 per 13,300 1 commercial benzol = 1 12,500 1 carburine (-689 specific gravity) . . . = 1 5,700 1 common petroleum spirit(-700 specific gravity) =1 4,300 (T. Stenhouse.) Gas will carry 3 per cent, benzol at 32 F. (Dr. Bunte.) 0-0033 gramme per litre per candle enrichment is required with toluene. 0*0034 gramme per litre per candle enrichment is required with benzene. 0*0028 gramme per litre per candle enrichment is required with benzene and H. 0*0115 gramme per litre per candle enrichment is required with heptane. 0-0027 gramme per litre per candle enrichment is required with xylene. 0-0026 gramme per litre per candle enrichment is required with napthalene and H. 0-0020 gramme per litre per candle enrichment is required with napthalene. 0-0064 gramme per litre per candle enrichment is required with phenol. (W.~ ' ' 390 GAS ENGINEER'S POCKET-BOOK. To Test between Petroleum Benzene and Benzene from Coal Tar. Use Syrian asphalte washed thoroughly with petroleum naptha to remove all constituents soluble. The colour of the mixture of the two benzenes after treatment with the asphalte varies from straw colour to dark brown according to the quantity of the coal tar benzene present, and these colours can be made to indicate the proportion of each benzene in the mixture. (Journal of the Society of Cliemical Industry.") Value of Acetylene as an Enriclier of Coal Gas. (Professor V. B. Lewes.) Composition of the Mixture. Illuminating Value. Enrichment Value of 1 Per Cent, in Candles. Coal Gas. Acetylene. Coal Gas. Mixture. 99-10 0-90 13 13-9 l-Oo 97-90 2-10 13 15-1 i-oo 96-00 4-00 13 17-3 1-07 95-20 4-80 13 18-4 1-12 91-00 9-00 13 23-5 1-16 89-50 10-50 13 25-3 1-17 85-00 15-00 13 33-0 1-33 83-25 16-75 13 36-1 1-36 66-90 33-10 13 60-5 1-43 55-50 44-50 13 76-7 1-43 16-70 83-30 13 175-2 1-94 oo-oo 100-00 240-0 2-40 The theoretical yield of acetylene is 25 Ibs. per 60 Ibs. of carbide approximate more correctly, 26 Ibs. to 64 Ibs. The following data for a 1,000 horse-power engine are based on the estimates of D. Adolph Frank, of Charlottenberg, and are intended to show the saving in space obtained. The engine is supposed to be run for 600 hours, and at 1-54 Ib. of coal per horse-power per hour would require about 420 tons, which would occupy about as many cubic metres. Liquid acetylene at 39 Ibs. per horse-power per hour would weigh about 108 tons, and occupy about 300 cubic metres, while carbide of calcium with 36 per cent, by weight of acetylene, need not occupy much more than 150 cubic metres, even after allowing for protective apparatus. In the latter cases the space occupied at present by the boilers would not be required. Acetylene with different proportions of air gives the following results : When 1,000 cubic inches of the mixture contain less than 77 cubic inches of acetylene, it will burn completely, producing water and carbon dioxide. When the proportion of acetylene is increased so that it forms from 77 to 174 cubic inches per 1,000 of the mixture, the product consists of water, carbon dioxide, carbon ACETYLENE. 391 monoxide and hydrogen, and the combustion is therefore imperfect. With larger proportions of acetylene free carbon and unaltered acetylene are left. When anything between 28 and 650 cubic inches of acetylene are present in 1,000 of the mixture it will take fire. (M. Le Chatelier.) Calcium carbide, CaC a -f H a O = C 2 H a + CaO. 1 Ib. CaC 2 makes about 6 cubic feet acetylene (C 2 H 2 ) of about 48 candle-power per foot. 10 volumes water will absorb 11 volumes acetylene gas at ordinary temperature and pressure. Iron burners are not suitable for use with acetylene gas, as the gas destroys the metal and enlarges the holes. Gas is evolved from calcic carbide until a pressure of 1,100 Ibs, per square inch is present. 87 Ibs. lime to 56J Ibs. C yield 100 Ibs. calcium carbide and 43f Ibs. CO. 100 Ibs. carbide yields 40*62 Ibs. acetylene and 115-62 Ibs. slaked lime, or 5*9 cubic feet of acetylene per Ib. carbide. Calcic carbide has specific gravity 2-262. is liquefied at '52 F. by a pressure of 21^ atmospheres. 1 Ib. liquefied calcic carbide will expand to 14 cubic feet at atmospheric pressure. Space required in generator 80 cubic inches per 1 Ib. carbide. 1 volume acetylene -f- 1 volumes air is slightly explosive. 1 , + 12 very * 1 +20 not Acetylene or ethine (C 2 H 2 ) is colourless, and burns with an intensely luminous flame, of the odour of rotten vegetables. Is made by the action of H 2 upon calcium carbide (CaC 2 ), the latter the produce of carbon and calcium burnt in an electrical furnace. Acetylene has approximately 15 times the lighting value of common gas, but has only two and a half times the heating value. Heat from 1 Ib. carbide during conversion to C,H 9 will boil 6 Ibs H 2 0. The Toxicity of Acetylene. M. Grehant found it is poisonous if inhaled in l.-n-ge quantities between 40 and 79 per cent. The amount of acetylene in Manchester gas never exceeds 0*05 per cent. 6-35 cubic feet C 2 H 2 gives 1 H.P. Specific gravity C. 2 H 2 = 0-91. 1 foot C 2 H 2 weighs about ;0688 Ibs. Comparison of Illuminating Value to Proportions of Acetylene. (Professor V. B. Lewes.) Analysis of Mixture. Acetylene at Top of Non-luminous Zone. Illuminating Value of Flame per 5 Cubic Feet. H. Acetylene. 65-5 43 -5 o-o 34-5 56-5 100-0 3-72 8-42 14-95 14-0 87-0 240-0 392 GAS ENGINEER'S POCKET-BOOK. Purified Lowe oil gas contains : H Saturated hydrocarbons, methane, &e. carbon, ethylene, &c. . CO N 22-6 31-9 13-4 29-2 0-6 2-3 100-0 (Professor Lewes, 1893.) Average Composition of Water Gas (Non-luminous). (Professor Lewes.) H . . 48-31 per cent. Methane . T05 per cent. CO . . 35-93 H 2 S . . 1-20 C0 2 . . 4-25 0-51 N . 8-75 Analysis of Water Gas. {Lancet). Hydrogen (H) Methane (CH 4 ) . Carbon monoxide (CO) Carbonic acid (C0 2 ) . Nitrogen (N) . Per Cent, by Volume. . 49-17 . 0-31 . 43-75 . 2-71 4-06 26 candle-power water gas consists of : Per Cent, by Volume. Hydrogen 34 Methane 15 Hydrocarbons absorbable by fuming sulphuric acid . 12-5 CO 33 Nitrogen from 0-5 to 5 Specific gravity equals 0'62 (air 1). (Butterfield.) Analysis of Carburetted Water Gas at Outlet of Exhausters. C0 2 . CO. CnH 2 n CH 4 H O . N 4-6 14-8 21-2 30-7 18-4 1-0 9-3 100-0 CARBURETTED WATER GAS PLANT. 393 Generator of million plant, generally 18 feet high, 10 feet diameter, with fire bars 4 feet from bottom, with 4 cleaning doors 8 feet from bottom, the upper portion coned to an opening about 2 feet diameter. Carburettor same size, but no doors, filled with checker bricks. Superheater 24 feet high, 10 feet diameter, also filled with checker bricks up to within 4 feet from top. Scrubber, 20 feet high, 6 feet diameter, filled with layers of wood strips placed checkerwise. Condenser, 20 feet high, 6 feet diameter, filled with 2-inch tubes. The generator, carburettor, and superheater are usually lined with fire-clay blocks 10 inches thick, with space of 2 inches between shells and bricks, tightly packed with a non-conductor. The blast inlet to the generator is below the fire bars, where the steam is also admitted. The blast inlet to the carburettor is at the top, and to the superheater at the bottom. Superheater usually 6 to 8 feet higher than the carburettor. Maximum pressure in shells, ordinary working, 40 inches water. Average 30 Pressure at which shells should be gas tight, 3 Ibs. per square inch. Pressure of air blast, 12 to 15 inches of water. Pressure of steam, 130 Ibs. per square inch. Blast mains usually No. 18 Birmingham wire gauge galvanized iron ; average blast 14 inches water. Blowers usually work 2,000 revolutions per minute. Temperature in generator should not be allowed to get below 1,000 C., and fuel of sufficient depth to convert the C0 2 to CO, provided, and the C should be in excess. Best temperature, about 1,100 C. Superheater must be kept at a temperature just below that required to separate the C from the oil vapours. Gradually increasing heats in carburettor and superheater best for fixing oil gas. Oil injected at from 25 to 30 Ibs. per square inch. Too low heats give a tarry stain on white paper held to pet cock on superheater. Too high heats give a deposit of carbon particles on white paper held to pet cock on superheater. Coke for feeding generators should be of even size and screened, giving little ash so that the steam may not pass through the fuel too freely. Coke must be fed regularly, say every two hours. Superheated steam obtained by use of boilers working at 130 Ibs. pressure. Blast pipes are often made of 16 Birmingham wire gauge, and are all connected by small pipes, so that the pressure is in all even when the fans are not running in every set. Two-inch safety tube is fixed just outside blast valve, so that if oil is leaking back through blast stop- valves on vessels the pressure causes a smoke to issue from the tube. One foreman superintends the work of gas making and clinkering. A gang of four men clinker three fires twice during eight-hour shift. 394 GAS ENGINEER'S POCKET-BOOK. A safety valve is fixed outside each blast inlet valve of the same bore as the pipe. Seal in seal pot, 3 inches. Tubes in condenser which comes after the scrubber, 1 inches diameter. In lighting up, fill up generator with coke and open the stack valve, shut generator charging door and turn on blast at generator ; when the brickwork of carburettor is red hot turn on blast there until superheater is red hot, and then put blast there until all are cherry red hot. If coke is required in generator before all are hot, shut all blast off and close stack valve, and then open charging door. In working, shut off blast first from generator, then carburettor, and then superheater, shut stack valve, then open oil feeder, and next turn on steam to generator and oil pumps. When gas making is finished, shut off oil, then steam to generator, open stack valve, and then open blast on superheater, carburettor, and generator. Average fuel required per 1,000 cubic feet gas made, 45 Ibs. Average oil required per 1,000 cubic feet gas made (distillate from Russian crude), 5'46. Candle power per gallon oil developed, 9-03. Percentage volume C0 2 in crude gas, 4 per cent, by volume. Illuminating power of gas, 24 '68 candles. Low heats or excess steam produce increase of C0 2 . Half million per day plant can be started in full working order in 3 hours. Temperature at which C decomposes water vapour to C0 2 and 2 H 2 equals 600 C. Temperature at which C decomposes water vapour to CO and H 2 equals 1,000 C. When steam superheated, or at, say, 130 Ibs. per square inch, is passed through fuel at 1,000 C., CO -j- H 2 are formed with about 3 per cent. C0 2 . To avoid explosions when lighting up, fill the generator to the top with fuel under slow fire without blast, and when blast is put on do not open the generator until it is at a working heat. Checker work requires renewing every six months (about) and should have superficial area of 16 square feet per 1,000 cubic feet made per diem, not including linings. By superheating, a considerable increase of illuminating power can be obtained with either crude petroleum (naptha) or pure paraffins. (Dr. H. Bunte.) The quantity of water gas produced from 1 Ib. of carbon is about 61 cubic feet at 600 F., and to produce this 4,200 heat units are absorbed, or about 70 units per cubic foot. With carburetfced water gas on a commercial scale 1,000 cubic feet of.22-candle gas can be produced from 50 Ibs. coke and 4 gallons oil*. Mix rich gases with poor ones as early as possible during manu- facture. ANALYSES OF CARBURETTED WATER GAS. 395 Analysis of Heating Gases Outlet of Outlet of Producer, Superheater. C0 2 . . . . 7-94 . . 15-10 CO 23-21 . . . 0-10 O .... .. 3-80 N 68-85 . . . 81-00 Proportions of C0 2 per Minute of Bun. Minutes 12345 Average. C0 8 . . 0-5 1-7 4-1 6-2 7-9 4'05 Percentage of CO., at End of Each Minute of a Five Minutes' Bun, at Outlet of Generator. (Butterfield.) 1st minute = 0-3 per cent. CO a 2nd = 0-6 3rd = 1-4 4th = 2-6 5th = 4-2 Average 1-82 Proportion of COa increases according to length of run. C0 2 in water gas varies from 1^ to 4 per cent. Only 3 per cent. C0 2 should be present in water gas, as it reduces the illuminating power of the gas. Percentage of C0 2 in uncarburetted water gas usually 4 to 5 per cent. CS 2 in carburetted water gas is about 4 grains. CO in crude carburetted water gas at Blackburn equals 28 or 29 per cent. Analysis of Crude Carburetted Water Gas. (Paddon and Goulden.) (Class of oil used, a rough distillate from Kussian crude.) H . 21-8 H 2 S and C0 2 . . 3-8 O 0-5 N . 2-2 CH 4 30-7 CnH 2 N .... 12-9 CO 28-1 At Blackburn, the total of five experimental runs with water gas (carburetted), 17,560,000 cubic feet gas of 22-77 illuminating power was made from 57,992 gallons " solar distillate " -875 specific gravity. 648,267 Ibs. coke was used, and 1,162,000 gallons water. Analysis of Water Gas. American English Practice. Practice. C0 2 .... 3-5 .. 3-87 CO 43-4 . . . 45-87 H 51-8 . . 49-55 N 1-3 ... 0-71 396 GAS ENGINEER S POCKET-BOOK, Carburetted water gas from coke should contain about 3 per cent. C0 2 . Carburetted water gas from coke should contain about 2 per cent. H a S. Sulphur compounds not exceeding 10 grains per 100 cubic feet. Cost of purifying Carburetted water gas equals l'043d. per 1,000 cubic feet. Carburetted water gas making requires only half the labour of coal gas, and saves -I7d. per 1,000 cubic feet for purification. Water gas can be enriched at the rate of 0-006 gramme per litre per candle. 26-candle carburetted water gas contains 60 percent, by volume of pure water gas. 26-candle gas is the most economical to make. Enriching value of 20 to 25 candle-power water gas (carburetted) equals about 20 per cent, more than its nominal value. (J. Methven.) Water gasper se has not any illuminating power. Solar distillate has specific gravity about -875 of flashing point 170 P. Solid residue from oil should not exceed 2 per cent, by weight. Water required for condensing carburetted water gas equals 90 gallons per 1,000 cubic feet. (A. G. Glasgow, 1892.) Approximate Analysis of Oil Gas Tar, from Condensers. (Paddon and Goulden.) Special gravity of Tar -996. Per Cent, by Volume. Per Cent, by Volume Without Water. Water 76-5 Benzene 0-28 1-19 Toluol 0-90 3-83 Light paraffins, &c. . . . Solvent naptha (zyloete) Phenol . . .... 2-0 4-15. only a trace 8-51 17-96 only a trace Middle oils (naptha, &c.) Creosote oil and green oil . . Napthalene .... 6-92 5-70 0-30 29-44 24-26 1-28 per cent, by weight Anthracene cake . . 0-22 contains 0-93 8-33 per cent. anthracene Coke 2-30 9-80 99-27 97-20 Loss , 0-73 2-80 100-00 100-00 CARBTJRETTED WATER GAS TAR, 397 Carburetted water gas tar contains about 70 per cent, water as it leaves the apparatus. Water used for cooling and scrubbing about 70 gallons per 1,000 cubic feet gas made, but this quantity is being reduced in modern plants to about 40 gallons. In America the production of oil gas tar by the Lowe process is about 12 per cent, of the oil used. To adequately protect petroleum tanks from lightning, it is neces- sary that all openings through which vapour can escape should be guarded with wire netting upon the principle of the Davy safety lamp. (Professor Neesen.) Joints in pipes for petroleum carrying should, preferably, be screwed, and when all oil has been removed from the threads, a good thick shellac varnish should be applied to the outside and inside threads. Yellow soap, treacle, honey, glue, mucilage, or glycerine are all quite petroleum proof. Canvas saturated with shellac varnish makes a good washer and might be used as the strip in riveted joints. Analysis of Belfast Carburetted Water Gas, C0 2 o . nil. nil. Unsaturated hydrocarbons CO Saturated hydrocarbons . H H . 10-7 per cent. . . 31-9 . 16-2 ., . , 33-7 7-5 100-0 C0 2 in crude gas 3'5 per cent. SH 2 .... -2 In water gas plant, at end of first minute gas should contain 0'3 per cent. C0 2 ; at end of second minute gas should contain 0'6 per cent. CO 2 ; at end of third minute gas should contain 1-4 per cent. C0 2 ; at end of fourth minute gas should contain 2*6 per cent C0 2 ; at end of fifth minute gas should contain 4*2 per cent. C0 2 . (Butterfield.) Crude water gas from coke (carburetted) will contain about 90 to 150 grains H 2 S per 100 cubic feet, and about 3 per cent. C0 2 , no ammonia, sulphur compounds not more than 10 grains per 100 cubic feet. Purification of water gas from C0 2 is twice that of coal gas. (Butterfield.) If air is forced through red hot coke, 1 Ib. of carbon in burning to CO liberates 4,451 -4 units of heat; but if burnt to carbon anhydride, 14,544 units. If there be sufficient body of carbon for this latter gas to pass through, it is decomposed with the absorption of 10,000 units of heat. 398 GAS ENGINEER'S POCKET-BOOK. One pound C requires 1J Ibs. 0, and forms 2j Ibs. CO, but air would contain for 1 Ibs. about 4 Ibs. N. If steam is forced through 1 Ib. C requires 1^ Ibs. steam to form CO. and this steam contains 1% Ibs. and $ Ib. H. One pound H burnt to water, yields 62,500 heat units, this -f- 6 = 10,416 heat units equal to quantity absorbed by the hydrogen ; and less 1,723 heat units (the heat already absorbed by the steam) equals 8,693 units, of which 4,500 will be supplied by the forming of CO, leaving 4,200 units to come from the previously heated coke. In practice more is taken from the coke, as the gases escape hot, (Norton H. Humphreys.) Steam brought into contact with an excess of carbon at 1,000 F. is decomposed into its component gases H and 0, and combines with the carbon to form CO + H. Equation of water gas production First action . 4 (H 2 0) + 2 C == 2 C0 2 + 8 H. Second action . 2 C0 2 + 8H + 2C = 4CO + 8H. (B. H. Thwaite.) The of steam attacks not only the surplus carbon, but also the hydrocarbon when mutually decomposing, as in water gas plants, bringing about the destruction of a large quantity of illuminating matter. (Young.) Ordinary producer gas contains about 30 per cent, by volume of combustible gases, and has a calorific value of about th that of 16- candle gas. If producer and water gas were mixed the mixture would consist of 30-5 H, 60 CO, and 60 N. Minimum temperature for formation of pure water gas, 1.800 F. To form sufficient heat for the production of 1 volume water gas 1'4 volumes producer gas are required. Temperature in water gas generator should never be lower than 1,000 C., and fuel should be of sufficient thickness to ensure as complete a conversion of the C0 2 to CO as possible. With hard anthracite coal it is possible to so arrange the tempera- ture in the generator that practically no C0 2 is formed, but with coke a percentage of the product is almost bound to be produced. H 2 S is also absent when anthracite is used, as it is formed from the S in the coke. Carburetted water gas plant at Blackburn Coke used per 1,000 cubic feet 30-8 Ibs. for generator. 6-1 boiler. ,/ 36-9 total. Oil, candles per gallon . . 6'97 Oil, specific gravity . . . '878 Mr. Foulis found that with ordinary water gas apparatus he re- quired 30 Ibs. to 40 Ibs. coke per 1,000 cubic feet of 30-candle gas using 6 gallons oil. CALORIFIC VALUE OF WATER GAS. 399 TJncarburetted water gas has only about half the calorific power of coal gas, but when carburetted to about 22 to 23 candles is about 85 per cent, to 95 per cent, the power. Semi water gas contains from 80 to 85 per cent, of the heating value of coal, and is the cheapest gas if supplied within a reasonable distance from the place of production. (A. Kitson.) Water gas from anthracite coal has a calorific value of 290 heat units. Water gas from bituminous coal has a calorific value of 350 heat units. (B. Loomis.) Difference in heating value of carburetted water gas and coal gas is as 9 to 10. Water gas, hydrogen, or mixtures of the two, when carburetted by the vapours obtained by decomposing hydrocarbons yield a flame which, although it may be of high illuminating value, is far shorter and smaller than the flame obtained from ordinary coal gas, and that in consequence of this it has to be burnt in larger quantities in order to obtain a flame which shall in appearance equal that of coal gas. This is due to the coal gas containing from 36 to 46 per cent, of methane, or light carburetted hydrogen, which gives body and length to the flame, and which only exists in carburetted water gas or hydrogen to the extent of from about 16 to 26 per cent. (Professor V. B. Lewes.) Carburetted water gas gives a small flame and lower durability than coal gas of equal illuminating power. Coal gas carburetted by petroleum gives larger flame and higher durability. The enriching value of 33-candle carburetted water gas is from 6 to 8 per cent, higher, and 47-candle carburetted water gas is 10 per cent, higher than when tested alone in the photometer. (A. Wilson.) Messrs. Frankland and Wright, and Dr. J. Louttit found by experiments with young rabbits that the effects of carbonic oxide were not more poisonous than ordinary coal gas. Approximate Cost of Water Gas per 1,000 Cubic Feet at 25 Candles. *. d. Oil, 4 gallons at 3%d . 12 45 Ibs. coke for generator, and 12 Ibs. for steam, J n 03 equal to 57 Ibs. at 12*. 6d. per ton . . . ( Labour 03 Purification 01 Wear and tear OJ 1 10 By the Van Steenbergh process 30 Ibs. to 40 Ibs. foundry coke are required per 1000 cubic feet gas made and carburetted with from 3 to 3 gallons naptha. Illuminating power equal to 22 candles ; loss of illuminating power by storage in cold weather, 2 candles. CO equal to 15 to 20 per cent. 400 GAS ENGINEER'S POCKET-BOOK. Composition and Illuminating Power of Gas from Van Steenbergh Process, with Different Fuels and 76 Naptha. (V. B. Lewes.) Gas Coke. Anthracite. Foundry Coke. Unpuri- lied. Purified. Unpuri- fied. Purified. H . 33-44 39-05 38-44 Marsh gas . . . 28-38 26-71 19-30 Illumiuants 11-14 9-27 7-49 CO . 19-00 13-50 23-81 C0 a . . . 2-24 (i'Ol 1-02 2-16 0-42 N . . . . 9-50 9-72 9-69 . 1-30 0-73 0-85 H 2 S . Illuminating power corrected nil ) 22-4 j' candles 0-35 nil 22-9 candles trace nil 21.8 candles. Manufacture of Dowsou Producer Gas. Superheated steam and air are passed through a generator con- taining a good body of incandescent fuel (preferably anthracite coal, but coke will do), the air supporting combustion ; the steam is decomposed, the combining with the C of the fuel, first making C0 2 , but on passing through the remainder of the hot fuel is reduced to CO, which is necessary to ensure that it has a sufficient affinity for to explosively combine with the of the air in the gas engine cylinders, while it must be remembered that each molecule of C0 2 makes two of CO. The gases are led through coolers and condensers when they are ready for use. 10 Ibs. of anthracite yield about 1,000 cubic feet of gas, but to this must be added 2 Ibs. of coke, required for the steam boiler. With Dowson gas 1 Ib. of fuel per I.H.P., or 1 Ibs. per break horse-power can be attained in a gas engine. Dowson gas is about equal to coal gas at Is. Qd. per 1,000 cubic feet, as about four or five times the quantity is required, and larger engines are necessary. One pound steam per 1 Ib. Welsh anthracite is usually allowed in Dowson gas. The producer must be kept hot, or tarry matters will be deposited. Dowson water gas has about one fourth or one fifth the explosive force of coal gas, but requires for its production^ only 14 Ibs. of anthracite coal per 1 ,000 cubic feet. Dowson producer gas contains from 45 to 48 per cent. N. Siemens producer gas generally contains 60 to 70 per cent. N, which renders rapid ignition difficult. FUEL GAS. 401 Heating value of Dowson gas, 150 British thermal units per cubic foot. Air required for complete combustion of Dowson gas equals 1 to 1, to 1J to 1, by volume of the gas. With Dowson gas the products of combustion must be expelled. In the Dowson producer 1 Ib. of steam is required per pound of anthracite. Dowson gas requires one and a half volumes of atmospheric air per volume of the gas for complete combustion. The initial pressure in gas engines is more than double that usually adopted in steam engines, and this gives the gas engine an advantage. A steam engine cannot convert into work more than 30 per cent, of the heat energy. A hot-air engine cannot convert into work more than 50 per cent, of the heat energy. An internally fired gas engine cannot convert into work more than 80 per cent, of the heat energy. (Professor Kennedy.) Coke for use in Dowson producers should be clean (not mixed with small coal or yard sweepings) and in pieces about 1 inch to 1^ inches cube. About 80 cubic feet Dowson gas made from coke are required per I. H. P. per hour. Gasholder required for Dowson gas for 100 I. H. P. plant is 8 feet diameter X 8 feet deep ; contents 400 cubic feet. Dowson gas has about one-fourth the explosive force of ordinary coal gas. The generator gas contains a large proportion of nitrogen and some C0 2 . CO does not ignite as rapidly as H. It is necessary to use a higher compression for a charge of generator gas than for ordinary town gas, so as to bring the molecules together. The volume of exhaust steam and products of combustion in a steam power plant is reduced 90 per cent, when gas power is used. If coal gas be subjected to sudden and severe refrigeration it will part with some of its valuable hydrocarbons, and this to a greater extent if the gas be stagnant. Nineteen to twenty candle gas, which has been purified by 2 per cent, air, does not lose any appreciable quantity of illuminating power during a travel of eight or nine miles through the town mains. Fuel Gas. Semi-water gas contains from 80 to 85 per cent, of the heating value of coal, and is the cheapest gas if supplied within a reasonable distance from the place of production. The producer consists essentially of a cylindrical shell of boiler- plate lined with fire brick. The internal diameter of the brick- work is 21 inches and the height from the grate to the top of the furnace is 3 feet. The grate is connected at one side with a steam and air injector, and on the other side with a gas supply-pipe. It is surrounded by a cast iron ashpit, A small reservoir or boiler is placed at one side, connected with which are two coils contained in .. D D 402 GAS ENGINEER'S POCKET-BOOK. the brickwork, the lower of which supplies steam and the upper one of which superheats it. Air channels are formed in the brickwork, arranged spirally, through which air is drawn by the injector and heated before mixing with the steam. The grate is provided with mechanism giving it a rotary and up-and-down movement to break up clinker or caking soft-coal. Five hundred cubic feet of gas per hour can be produced from 6 Ibs. or 7 Ibs. of coal. (A. Kitson.) Peebles Process. The retorts used in the Peebles process yield 500 cubic feet of gas per hour, and 5 cwts. (per ton of oil decomposed) of hard graphite coke. Heat required for fresh oil in Peebles process retorts equals 1,100 to 1,200 F. For condensible products, 1,400 F. Oil of '850 specific gravity gave 5 cwt. coke per ton at Perth. Enriching value of Peebles oil gas is 50 per cent, higher than the illuminating power when burnt alone. (S. Glover.) Peebles oil gas used as an enricher has prevented the stoppage of services with napthalene during the most severe winter. One ton of tar from Durham coal by the Peebles process yields 15,000 cubic feet of 25 candle gas, and 15 cwt. coke of good quality. (Bell.) Dr. Stevenson Macadam stated (1887) that he considered 6,885 Ibs. of sperm light as the theoretic value of the gas from 1 ton of oil. He found mixing oil, gas, and air entailed a loss of illuminating power ; after making all allowance for the admixture, he advocated the use of water gas as a diluent for oil gas. To gasify tar permanently about 2,000 F. is required. It has been suggested when supply of gas is short to mix about 2 gallons of tar per charge with the coals, and thus keep up the illuminating power. Oases passed over Gasolene at 50 F. will completely evaporate it, giving air an illuminating power of 60 candles, and poor gas an illuminating power of 80 candles. No condensation has been found in the syphon boxes in the district in Kochdale, when carburine has been used as an enricher. It is best when enriching with a cold process to put the enriching apparatus on the delivery pipe from the works. One Gallon Carburine (specific gravity 0'680) will raise 8,000 cubic feet 1 candle. Yield of Gas in Pintsch System equals 81 to 83 cubic feet per gallon of 51 candles ; compression to 150 Ibs. per square inch, reduces illuminat- ing power to 38 candles, and deposits one gallon hydrocarbon per 1,000 cubic feet. (J. Tomlinson.) Cost of fitting gas to railway carriages (Pintsch or Pope systems) equals about 5 per lamp, including its proportion of reservoirs, pipes, gauges, &c. Cost of working about ^ths of a penny per lamp per hour equals about one-half that of oil. Maintenance costs about 2*. per lamp per year. COMPRESSING COAL GAS. 403 Loss in Volume of Coal Gas when Compressed. (C. E. Botley.) Illuminating power of gas 16-50 candles. Pressure. Volume. Loss. Lbs. per Square Inch. Atmo- spheres. Gas put into Cylinder. Gas used per Meter. CuMc Feet. Per Cent. 45 3 510 510 nil. nil. 75 5 850 860 10 1-16 105 7 1,190 1,205 15 1-24 135 9 1,530 1,570 40 2-54 1G5 11 1,870 1,920 50 2-60 195 13 2,210 2,330 120 5-15 200 1*1 2,267 2,450 183 7-47 Notes on Suction Gas Producers. The gases made are said to be very equal in quality and character. The producer should be stoked every 2 or 3 hours, but can be left for 5 or 6 hours if necessary. If closed down for a week they will probably be found alight. Larger valves are required in the engines than for town's gas. The gas comes off in from 15 to 20 minutes after starting with all cold. Magneto ignition is necessary. H . CH 4 CO . N C0 3 . Average Composition of Suction Gas. . 57-41 B.T.U. 19-17 17-6 per cent. 1-6 18-6 54-4 7-2 99-4 60-17 136-75 r> D 2 404 GAS ENGINEER'S POCKET-BOOK. PRODUCTS WORKS. Chimneys in chemical works should be at least 250 feet high. The simplest form of sulphate plant is a boiler in which the liquor is heated, and from which a pipe to convey the vapours is carried to the sulphuric acid in the saturator where sulphate crystals are formed. The addition of lime or caustic soda to the liquor in the boiler causes the ammonia, combined with other gases which are in the liquid, to pass off as gas, and consequently be converted into sulphate. Seventeen parts pure ammonia combine with 49 parts pure sulphuric acid to form 66 parts sulphate of ammonia (2 (NHJ SOJ. Reaction of Ammonia cal Liquor and Sulphuric Acid. 2 NH 3 + H 2 SO, = 2 (NHJ S0 4 . The volatilization of the ammonia from gas liquor in all modern plant is effected by means of continuous working stills, viz., distilling a regular stream of liquor as it flows by its own gravity through the intricacies of a still heated by direct steam. To calculate amount of Sulphate of Ammonium to be obtained from Liquor. Ounce strength X 1'347 X gallons of liquor equals ounces weight of sulphate ; or, ounce strength X '0841 equals Ibs. sulphate per gallon. 2,000 gallons of 8-ounce liquor will produce 15 cwt. sulphate, requiring also 13 J cwt. of sulphuric acid, or, say, 1 ton sulphate per 100 tons of coal in small works. One per cent. N in coal equals 105 Ibs. ammonium sulphate (pure). (Butterfield.) Coal may be said to contain 1J per cent. N equal to 140 Ibs. sulphate of ammonia per ton ; it is not usual to obtain more than 27 or 28 Ibs. sulphate. In sulphate plant it is necessary that the condensers and purifiers be of ample capacity. Mr. Croll proposed to make sulphate of ammonia by passing the products of combustion from a coke furnace through a " coffey " still containing ammoniacal liquor, and then precipitating the sulphate in the usual saturator. He thus obtained an increase of sulphate per gallon of acid, and greatly lessened the quantity of H 2 S given off. Of the 1-7 per cent, of N in the coal, only about -25 per cent, appears as ammonia after carbonization. Some coals contain as much as 2 per cent. N. If all the N were converted into NH 8 , sulphate would equal 215 Ibs. per ton of coal. About 50 per cent, of the N remains in the coke. About '027 per cent, of the N in the coal forms in the SULPHATE MANUFACTURE. 405 purifiers calcium cyanide and calcium cyanate. If steam, water gas or hydrogen were passed through heated coke, a large proportion of the N could be removed, and afterwards converted, and with that already evolved with the gas a make of about 1 cwt. of sulphate per ton could be obtained. One ton sulphate equals about 5 cwt. NH.a One ton 10-ounce liquor equals about 51 Ibs. NH 3 equals 2 per cent. One ton sulphate equals 11 tons 10-ounce liquor. One ton coal produces 35 to 40 gallons 10-ounce liquor equal to 30 to 35 Ibs. sulphate. 7,000 gallons liquor require Yield as Compared with Theory. Hours. Per Cent. When heated by open fire from without . . 22 90'0 When heated by a steam coil (indirect steam) .18 . 92*0 When open steam is blown in . . . . 14 98*5 (Dr. Lunge.) The liquor in the saturator should be kept about 54 Twaddell. Efficient sulphate plant requires about 8 cwt. fuel per ton sulphate made. Temperature in sulphate well equals 75, after passing jet elevator 116. In the economiser 180. (S. Ellery.) The waste gases from the saturator have usually a temperature of 186 F., and by utilizing these the liquor can be raised to about 113 F. According to the reports of the Chief Inspector under the Alkali Works Regulation Act, the make of sulphate of ammonia was For 1894. Tons. In Gasworks . 110,748 Ironworks . 11,000 Shale works 23,105 Coke and Carbonizing Works . . . 4,973 Totals . . 149,826 To manufacture sulphuric acid, burn S, and pass with peroxide of nitrogen, air and steam, in regulated quantities to a large chamber, where H 2 S0 4 condenses, and is of sufficient strength for the manu- facture of sulphate (equation 2 S0 2 + N0 4 + 2 H 2 = 2 H 2 S0 4 + NO,). Sulphate of ammonia contains 20 per cent, of nitrogen, and nitrate of soda only 15 per cent. Three-quarters of a ton of sulphate has in it as much food for a crop as a ton of nitrate. Of course it is true that the nitrogen in the nitrate is accepted as being more effective than the nitrogen in the sulphate, but the outside difference in manurial power is certainly not more than 10 per cent. 406 GAS ENGINEER'S POCKET-BOOK. When it is also remembered that the more concentrated nature of sulphate means a saving of 25 per cent, on the carriage, and that it can often be bought at still lower rates from local gasworks, it is clear that for any other than very light sandy soils, sulphate rather than nitrate should be bought at present. Professor Somerville states that sulphate of ammonia and nitrate of soda are nearly of equal value per unit of nitrogen as manures, therefore 861bs. sulphate equals 112 Ibs. nitrate. Sulphate of ammonia has proved itself a better nitrogenous manure for mangolds than nitrate of soda. One-eighth cwt. sulphate of ammonia per acre on hay land is the best dressing ; or f cwt. sulphate equals 1 cwt. nitrate of soda. Preliminary nitrification of sulphate of ammonia is not necessary when using the latter as a manure. From Coal Tar are obtained by distillation the following valuable bodies : benzene, toluene, naptha, carbolic acid, creosote, anthracene, napthalene, and a residue of pitch. The benzene and toluene yield aniline whence the dyes magenta and methyl violet are obtained ; the phenol and creosote form the basis of valuable antiseptic and dis- infectant preparations, and the first-named is also the source of the dye aurine ; naptha is valuable chiefly as a rubber solvent ; naptha- lene yields napthylamine, abeta-napthol, vermillene, scarlet, and napthol yellow ; anthracene gives on treatment alizarin, from which a great number of beautiful dyes are prepared. By itself, also, coal tar has many applications, as, for instance, for making gas as fuel, and as a preservative for building materials. Then should be mentioned the legion of coal tar derivatives : antipyrin, antifebrin, analgen, exalgine^ salol, saccharin, and salicylic acid. (Lancet.) Constituents of Coal Tar. Average Weight Per Proportionate Weight of Constituents. Calorific Value. Cent. C. H. C. H. Units. Units. First runnings C 6 H 10 3 025714 004286 200 148 Light oil . . CgHu 7 061091 008910 474 307 Middle oils Ci2H places where incandescent burners are used for street-lighting, one street lamp in each street or group of streets may be provided under the lantern with a branch closed by a screw stopper. The Gas Examiner shall in such cases connect the pressure-gauge by screwing to it an |_-shaped pip e fitted with a union, by means of which it may be connected to the service pipe in the place of the screw stopper. The |_-shaped pipe is to be of such dimensions as to enable the pressure-gauge to be fixed outside the lantern but at about the game level as the incandescent burner. It should be provided with a tap. The gauge to be used for this purpose consists of an ordinary pressure-gauge enclosed in a lantern, which also holds a candle for throwing light upon the tubes and scale. The difference of level of the water in the two limbs of the gauge is read by means of a sliding scale, the zero of which is made to coincide with the top of the lower column of liquid. The Gas Examiner having fixed the gauge gas-tight, and as nearly as possible vertical on the pipe of the lamp, and having opened the cocks of the lamp and gauge, shall read and at once record the pressure shown. From the observed pressure one-tenth of an inch is to be deducted to correct for the difference between the pressure of gas at the top of the lamp column and that at which it is supplied to the basement of neighbouring houses. The pressure prescribed in the Acts of the three Metropolitan Gas Companies is to be such as to balance from midnight to sunset a column of water not less than one inch in height. Meters. Each of the meters used for measuring the gas consumed in making the various testings is constructed with a measuring drum which allows one-twelfth of a cubic foot of gas to pass for every revolution. A hand is fastened directly to the axle of this drum and passes over a dial divided into one hundred equal divisions. The dial and hand are protected by a glass. In the meter employed in testing the purity of gas the pattern of dial for showing the number of revolutions and the automatic cut-off hitherto in use shall be retaineo but in the meter employed for testing illuminating power, only the dial above described is needed. The meters should be provided with Fahrenheit thermometers. The stop-clock may be either attached to the meter or separate. The meters used for measuring the gas consumed in making the various testings having been certified by the Referees, shall, at least once in seven days, be proved by the Gas Examiners by means of the Referees' one-twelfth of a cubic foot measure. No meter other than a wet meter shall be used in testing the gas under these instructions. EE2 420 GAS ENGINEER'S POCKET-BOOK. APPENDIX A. TJie Ten- Candle Pentane Lamp. Mr. Harcourt's Ten-Candle Pentane Lamp is one in which air is saturated with peutane vapour, the air-gas so formed descending by its gravity to a steatite ring burner. The flame is drawn into a definite form, and the top of it is hidden from view by a long brass chimney above the steatite burner. The chimney is sur- rounded by a larger brass tube, in which the air is warmed by the chimney, and so tends to rise. This makes a current which, descending through another tube, supplies air to the centre of the steatite ring. No glass chimney is required, and no exterior means have to be employed to drive the pentane vapour through the burner. Figure 1 shows the general appear- ance of the lamp. The saturator A is at starting about two- thirds filled with pentane.* It should * CAUTION. Pen- tane is extremely in- flammable ; it gives off at ordinary tem- peratures a heavy vapour which is liable to ignite at a flame at a lower level than the liquid. TJie saturator must never have pentane poured into it when in position, if the lamp or tJie gas of the pnoiometer is alight. ILLUMINATING POWER AND PURITY OF GAS. 421 be replenished from time to time so that the height of liquid as seen against the windows may not be less than one-eighth of an inch. The saturator A is connected with the burner B by means of a piece of wide india-rubber tube. The rate of flow of the gas can be regulated by the stop-cock S 2 , or by checking the ingress of air at S^ For this latter purpose a metal cone, acting as a damper, is suspended by its apex from one end of a lever, to the other end of which is attached a thread for moving the cone up or down. The lever is supported by an upright arm clamped to the upper end of the stop-cock immediately beneath the cone. From the top of the lamp the thread descends to a small pulley on the table, and thence passes horizontally to the end of a screw moving in a small block, by turning which the Gas Examiner can regulate the lamp without leaving his seat. It is best so to turn the stop-cock 82 as to allow the flame to be definitely too high, but not to turn it full on, before letting down the regulating cone to its working position. Both stop-cocks should be turned off when the lamp is not alight. The chimney tube C C should be turned so that no light passing through the mica window near its base can fall upon the photoped. The lower end of this tube should, when the lamp is cold, be set 47 millimeters above the steatite ring burner. A cylindrical boxwood gauge, 47 millimeters in length and 32 in diameter, is provided with the lamp to facilitate this adjustment. The exterior tube D com- municates with the interior of the ring-burner by means of the connecting box above the tube $ and the bracket F on which the burner B is supported. A conical shade G is provided. This should be placed BO that the whole surface of the flame beneath the tube C may be seen at the photoped through the opening. The lamp should be adjusted ' by its levelling screws so that the tube E, as tested with a plumb-line, is vertical, and so that the upper Burface of the steatite burner is 353 millimeters from the table. A gauge is provided to facilitate this latter measurement. The tube C is brought centrally over the burner by means of the three adjusting screws at the base of the tube D. These three screws should not be quite screwed up, but only sufficiently so to keep the chimney tube central. The adjustment is facilitated by nvaans of the boxwood gauge. When the lamp is in use the stop-cocks are to be regulated so that the tip of the flame is about half-way between the bottom of the mica window and the cross-bar. A variation of a quarter of an inch either way has no material influence upon the light of the flame. The saturator A should be placed upon the bracket as far from the central column as the stop at the end will allow. If it is found that, after the lamp has been lighted for a quarter of an hour, the tendency of the flame is to become lower, the saturator may be placed a little nearer the central column. To prevent a gradual accumulation of dust in either the burner or the air-passage, a small cover of the size of the top of B and shaped like the lid of a pill-box should be kept upon the lamp when not in use. 422 GAS ENGINEER'S POCKET-BOOK. APPENDIX B. The pentane to be used in the 10-candle lamp should be prepared and tested in the following manner : PREPARATION. Light American petroleum, such as is known as gasoline and used for making air-gas, is to be further rectified by three distillations, at 55 C., 50, and 45 in succession. The dis- tillate at 45 is to be shaken up from time to time during two periods of not less than three hours each with one-tenth its bulk of (1) strong sulphuric acid, (2) solution of caustic soda. After these treatments it is to be again distilled, and that portion is to be collected for use which comes over between the temperatures of 25 and 40. It will consist chiefly of pentane, together with small quantities of lower and higher homologues whose presence does not affect the light of the lamp. TESTING. The density of the liquid pentane at 15 C. should not be less than 0*6235 nor more than 0*626 as compared with that of water of maximum density. The density of the pentane when gaseous, as compared with that of hydrogen at the same tempera- ture and under the same pressure, may be taken. This is done most readily and exactly by Gay Lussac's method, under a pressure of about half an atmosphere and at temperatures between 25 and 35. The density of gaseous pentane should lie between 36 and 38. Any admixture with pentane of hydrocarbons belonging to other groups and having a higher photogenic value, such as benzene or amylene, must be avoided. Their presence may be detected by the following test. Bring into a stoppered 4-oz. bottle of white glass 10 cc. of nitric acid, specific gravity T32 (made by diluting pure nitric acid with half its bulk of water) ; add 1 cc. of a dilute solu- tion of potassium permanganate, containing O'l gram of perman- ganate in 200 cc. Pour into the bottle 50 cc. of the sample of pentane, and shake strongly during five successive periods of 20 seconds. Tf no hydrocarbons other than paraffins are present, the pink colour though somewhat paler, will still be distinct ; if there is an admixture of as much as per cent, of amylene or benzene, the colour will have disappeared. APPENDIX D. The Table Photometer. The several parts of the apparatus stand upon a well-made au67 963 958 953 949 944 939 283 990 985 980 976 971 966 961 957 952 947 942 28-4 993 988 984 979 974 970 965 960 955 951 946 285 997 992 987 983 978 973 968 964 959 954 949 286 1-001 995 991 986 981 977 972 967 962 958 953 287 1-001 999 994 990 985 980 975 970 966 961 956 288 1-007 1-003 998 993 988 984 979 974 969 964 959 28-9 1-011 1-006 1-001 997 992 987 982 977 973 968 963 290 1-014 1-010 1-005 1-000 995 990 986 981 976 971 966 291 1-018 1-013 1-008 1-004 999 994 989 984 979 975 969 292 1-021 1-017 1-012 1-007 1-002 997 992 988 982 978 ' -973 293 1-025 1-020 1-015 rou 1-006 1-001 996 991 986 981 976 294 1-028 1-024 1-019 1-014 1-009 1-004 999 995 990 985 980 295 1-032 1-027 1-022 1-018 1-013 1-008 1-003 998 993 988 983 296 1-036 1-031 1-026 1-021 1-016 1-011 1-006 1-001 996 992 986 29-7 1-039 1-034 1-029 025 1-019 1-015 1-010 L-005 1-000 995 990 298 1-043 1-038 1-033 028 1-023 1-018 1-013 1-008 1-003 998 993 299 1-046 1-041 1-036 031 1-026 1-022 1-017 1-012 1-007 1-002 997 300 1-050 1-045 1-040 035 1-030 1-025 1-020 1-015 1-010 1-005 i-ooc 301 1-053 1-048 1-043 038 1-033 1-029 1-024 1-019 1-014 1-009 1-002 302 1-057 1-052 1-047 042 1-037 1-032 027 1-022 1-017 1-012 1-007 303 1-060 1-055 1-050 1-045 1-040 1-036 030 1-025 1-020 1-015 1-01C 304 1-064 1-059 1-054 1-049 1-044 1-039 034 1-029 1-024 1-019 1-01-1 305 1-067 1-062 1-057 1-052 1-047 1-042 1-037 1-032 1-027 1-022 1-01? 306 1-071 1-066 1-061 1-056 1-051 1046 041 1-036 1-031 1-026 1-02C 307 1-074 1-069 1-064 1-059 1-054 1-049 044 1-039 1-034 1-029 1-024 308 1-078 1-073 1-068 1-063 1-058 1-053 048 1-043 1-037 1-032 1-027 309 1-081 1-076 1-071 1-066 1-061 1-056 051 1-046 1-041 1-036 1-031 310 1-085 1-080 1-075 1-070 1-065 1-060 055 1-049 1-044 1-039 1-034 %* The numbers in the above table have been calculated from the formi temperature on the Fahrenheit scale, and a the tension of aqueous vapc volume at 60 and 30 incl ILLUMINATING POWER AND PURITY OF GAS. APPENDIX G. THE VOLUME OF GAS MEASURED OVER WATER AT DIFFERENT TEMPERA- ATMOSPHERIC PRESSURES. Bar. Thermometer Fahrenheit. 62 64 66 68 70 72. 74 76 78 8(X 82 84 280, 927 922 917 912 907 902 897 892 887 881 875 870 281 930 926 921 916 911 905 900 895 890 884 879 873 282 934 929 924 919 914 909 904 898 893 887 882 876 283 937 932 928 922 917 912 907 902 896 891 885 880 284 941 936 931 926 921 915 910 905 900 894 888 883 285 944 939 934 929 924 919 914 908 903 897 892 886 286 947 943 938 932 927 1 -922 917 912 906 901 895 889 28-7 951 946 941 936 931 925 920 915 909 904 898 *93 288 954 949 944 939 934 929 924 918 913 907 901 896 289 958 953 948 942 937 932 927 921 916 910 905 899 290 961 956 951 946 941 935 930 925 919 914 908 903 291 964 959 954 949 944 939 933 928 923 917 911 906 292 968 963 958 952 947 942 937 931 926 920 914 909 293 971 966 961 956 950 945 940 935 929 923 918 912 294 975 969 964 959 954 949 .-943 938 932 927 921 915 295 978 973 968 962 957 952 947 941 936 930 924 919 296 981 976 971 966 960 955 950 944 939 933 927 922 297 985 980 974 969 964 959 953 948 942 937 931 925 298 988 983 978 972 967 962 957 951 946 940 934 928 299 991 986 981 976 970 965 960 954 949 943 937 932 300 995 990 985 979 974 968 963 958 952 946 941 935 301 998 993 988 983 977 972 966 961 955 950 944 938 302 1-002 996 991 986 980 975 970 964 959 953 947 941 303 1-005 1-000 995 989 984 978 973 968 962 956 950 945 804 1-008 1-003 998 993 987 982 976 971 965 959 954 948 305 1-012 1-006 1-001 996 990 985 980 974 969 963 957 951 306 1-015 1-010 1-005 999 994 988 983 977 972 966 960 954 307 1-018 1-013 1-008 1-003 997 992 986 981 975 969 963 957 308 1-022 1-017 1-011 1-006 1-000 995 990 984 978 972 967 961 309 1-025 1-020 1-015 1-009 1-004 !98 993 987 982 976 970 964 310 1-029 1-023 1-018 1-013 1-007 1-002 996 991 985 979 973 967 17 ' 6 . 4 J^,"" ' ^' where h is the height of the barometer in inches, t the at t. If v is any volume at t and h inches pressure and V the corresponding pressure, V = v n. 428 GAS ENGINEER'S POCKET-BOOK. APPENDIX H. Test for Sulphuretted Hydrogen^ The apparatus represented by Fig. 12 consists of a plate with a circular channel half filled with mercury in which rests a bell-glass, held down in position by an arm and cap not shown in the figure. A central tube connected below with the gas-inlet rises nearly to the top of the bell-glass, and carries midway wires pointed and curved at the end, from each of which a slip of lead-paper hangs. OBD Fig. 12. A second pipe passing through the plate and terminating above in a short elbow provides an outlet for the gas, which is burnt as it issues from a governor burner passing gas at about the rate of five cubic feet per hour APPENDIX K. Sulphur Ibst. The apparatus to be employed is represented by Fig. 13, and is of the following description : The gas is burnt in a small Bunsen burner with a steatite top, which is mounted on a short cylindrical stand, perforated with holes for the admission of air, and having on its upper surface, which is also perforated, a deep circular channel to receive the wide end ot a glass trumpet-tube. There are both^in the side and in the top of this stand fourteen holes of five millimeters in diameter, or an equivalent air-way. On the top of the stand, between the narrow stem of the burner and the surrounding glass ILLUMINATING POWER AND PURITY OP GAS. 429 trumpet-tube, are to be placed pieces of commercial sesqui-carbonate of ammonia weighing in all about two ounces. The products both of the combustion of the gas and of the gradual volatilisation of the ammonia salt go upwards through the trumpet- tube into a vertical glass cylinder with a tubulure near the bottom, and drawn in at a point above this to about half its diameter. From the contracted part to the top the cylinder is packed with balls of glass about fifteen millimeters in diameter, to break up the current and promote condensation. From the top of this condenser there proceeds a long glass pipe or chimney slightly bent over at the upper end, serving to effect some further conden- sation, as well as to regulate the draught and afford an exit for the uncondensable gases. In the bottom of the condenser is fixed a small glass tube, through which the liquid formed during the testing drops into a flask placed beneath. The following cautions are to be observed in selecting and setting up the apparatus : See that the inlet-pipe fits gas-tight into the burner, and that the holes in the circular stand are clear. If the burner gives a luminous flame, remove the top piece, and having hammered down gently the nozzle of soft metal, perforate it afresh, making as small a hole as will give passage to two-thirds of a cubic foot of gas per hour at a convenient pressure. See that the tubulure of the con- denser has an internal diameter of not less than 18 millimeters, and that its Fig. 13. outside is smooth and of the same size as the small end of the trumpet- tube ; also that the internal diameter of the contracted part is not less than 30 millimeters. See that the short piece of india-rubber pipe fits tightly both to the trumpet-tube and to the tubulure of the condenser. The small tube at the bottom of the condenser should have its lower end contracted, so that when in use it may be closed by a drop of water. The india-rubber pipe at the lower end of the chimney-tube should fit into or over, and not simply rest upon, the mouth of the condenser. A central hole, about 50 millimeters in diameter, may with advan- tage be made in the shelf of the stand. If a beaker is kept on the table below, the liquid will still be preserved if by any accident the flask is not in its place. 430 GAS ENGINEER'S POCKET-BOOK. APPENDIX L. The Gas Caloj-imeter. The gas calorimeter, which has been designed by Mr. Boys, is shown m vertical section in Fig. 14. It consists, of three parts, which may be separated, or which, if not in position, may be turned rela- tively to one another about their common axis. The parts are (1) the base A, carrying a pair of burners B, and a regulating tap. The upper surface of the base is covered with a bright metal plate held in place by three centering and lifting blocks C. The blocks are so placed as to carry (2) the vessel D which is provided with a central copper chimney E and a condensed water outlet F. Besting upon the rim of the vessel D are (3) the water circulating system of the calorimeter attached to the lid G. Beginning at the centre where the outflow is situated there is a brass box which acts as a tem- perature equalising chamber for the outlet water. Two dished plates of thin brass K K are held in place by three scrolls of thin brass L L L. These are simply strips bent*ouud like unwound clock springs, so as to guide the water in a spiral direction inwards, then outwards and then inwards again to the outlet. The lower or pendent portion of this box is kept cool by circulating water, the channel for which may be made in the solid metal, as shown, on the right side, or by sweating on a tube as shown on the left. Connected to the water channel atlhe lowest point by a union are five or six turns of copper pipe such as is used in a motor-car radiator of the kind known as Clarkson's. In this a helix of copper wire threaded with copper wire is wound round the tube, and the whole is sweated together by immer- sion in a bath of melted solder. A second coil of pipe of similar con- struction surrounding the first is fastened to it at the lower end by a union. This terminates at the upper end in a block, to which the inlet water box and thermometer holder are secured by a union as shown at 0. An outlet water box P and thermometer holder are similarly secured above the equalising chamber H. The lowest turns of the two coils M N are immersed in the water which in the first instance is put into the vessel D. Between the outer and inner coils M N is placed a brattice Q made of thin sheet brass, containing cork dust to act as a heat insulator. The upper annular space in the brattice is closed by a wooden ring, and that end is immersed in melted rosin and beeswax cement to protect it from any moisture which might condense upon it. The brattice is carried by an internal flange which rests upon the lower edge of the casting H. A cylindrical wall of thin sheet brass, a very little smaller than the vessel D, is secured to the lid so that when the instrument is lifted out of the vessel and placed upon the table, the coils are protected from injury. The narrow air space between this and the vessel D also serves to prevent interchange of heat between the calorimeter and the air of the room. The two thermometers for reading the water temperatures and a third for reading the temperature of the outlet air are all near together and at the same level. ^The lid may be turned round into any position relatively to the gas inlet and condensed water drip that ILLUMINATING POWER AND PURITY OF GAS. 431 432 GAS ENGINEER'S POCKET-BOOK. may be convenient for observation, and the inlet and outlet water boxes may themselves be turned so that their branch tubes point in any direction. A regular supply of water is maintained by connecting one of the two outer pipes of the overflow funnel to a small tap over the sink. The overflow funnel is fastened to the wall about one metre above the sink and the other outer pipe is connected to a tube in which there is a diaphragm with a hole about 2'3 mm. in diameter. This tube is connected to the inlet pipe of the calorimeter. A piece of stiff rubber pipe long enough to carry the outflow water clear of the calorimeter is slipped on to the outflow branch and the water is turned on so that little escapes by the middle pipe of the overflow funnel, and is led by a third piece of tube into the sink. The amount of water that passes through the calorimeter in four minutes should be sufficient to fill the graduated vessel shown in Fig. 16 to some point above the lowest division, but insufficient in five minutes to come above the highest division. If this is not found to be the case, a moderate lowering of the overflow funnel or reaming out of the hole in the diaphragm will make it so. The overflow funnel should be provided with a lid to keep out dust. The thermometers for reading the temperature of the inlet and outlet water should be divided on the centigrade scale into tenths of a degree, and they should be provided with reading lenses and pointers, that will slide upon them. The them ometcrs are held in place by corks fitting the inlet and outlet water boxes. The positions of these thermometers should be interchanged every month. The thermometers for reading the temperature of the air near the instru- ment and of the effluent gas should be divided on the centigrade scale into degrees. The flow of air to the burners is determined by the degree to which the passage is restricted at the inlet and at the outlet. The blocks C which determine the restriction at the inlet are made of metal ^ inch or about 5 millimeters thick, while the holes round the lid which determine the restriction at the outlet are five in number and are |ths inch or 16 millimeters in diameter. The thermometer used for finding the temperature of the effluent gas is held by a cork in the sixth hole in the lid so that the bulb is just above the upper coil of pipe. The calorimeter should stand on a table by the side of a sink so that the condensed water and hot water outlets overhang and deliver into the sink. A piece of india-rubber tube reaching nearly to the base should be attached to the waste water-pipe, so as to avoid splashing, and another piece may conveniently be slipped on to the condensed water outlet so as to lead the condensed water into a flask, but care should be taken that the small side hole is not covered by the tube. A glass vessel must be provided of the size of the vessel D containing water in which is dissolved sufficient carbonate of soda to make it definitely alkaline. The calorimeter after use is to be lifted out of its vessel D and placed in the alkaline solution and there left until it is again required for use. The liquid should not, when the calorimeter is placed in it, come within two inches of the top of the vessel. The ILLUMINATING POWER AND PURITY OF GAS. 433 liquid must be replenished from to time, and its alkalinity must be maintained. lbo c- Mil- 1,1 METRt 5 . a.E. Fig. 16. F P 434 GAS ENGINEERS POCKET-BOOK. CALORIFIC POWER OP GAS. ifORM WITH EXAMPLE OF CALCULATION (see p. 418), Water. Air. Inlet. Outlet. Inlet. Outlet. 4 minutes 2 seconds = 242 8'45 0. 33-22 C. 15 C. 12 C. seconds. 23 One-sixth difference = 0'5. 23 23 Barometer, 29'9 inches ...1 Tabular 8-46 -21 Meter thermometer, 60 F. ) number = -997. 22 OQ 23 Water collected, 2-080 litres. ._ .p ? Condensed water in 20 minutes = 1200 seconds, 40-3 c.c. 22 21 .no 8-47 '24 Log. 24-77 = 1-3939 8-46 '24 Log. 3 = -4771 24 Log. 2-080 = -32W 5) 3-41 2-1891 3) -682 Log. -997 = 1-9987 33-23 Log. 155-0 8-46 Subtract 0-5 = 2-J004 = Gross calorific power. 154-5 Log. 40-3 = 1-605 Log. 242 = 2-384 Log. 1200 Log. -997 = 3-079 = 1-999 Log. 1-86 = -270 3-078 Gross 154-5 3-Q78 Log.. 15-2 = 1-181 139-3 = Net calorific power. ILLUMINATING POWER AND PUllITtf OF GAS. GAS REFEREES' STANDARD BURNER. (Applicable to the Old ^Regulations.) The burner which has been adopted as the Standard Burner for testing gas was designed by Mr. Sugg, and was called by him " Sugg's London Argand, No. 1." A half-sized section is appended, in which A represents a supply pipe, B the gallery, C the cone, D the steatite chamber, E the chimney. The following are the dimensions of those parts of the burner upon which its action depends : Inch. Diameter of supply pipes . . . 0'08 External diameter of annular steatite chamber 0*84 Internal diameter of do. . . . 0'48 Number of holes 24 Diameter of each hole .... 0'045 Internal diameter of cone : At the bottom 1-5 At the top 1-08 Height of upper surface of cone and of steatite chamber above floor of gallery 0-75 Height of glass chimney ... 6 Internal diameter of chimney . 1'875 FF2 436 < | i IS S 'i Q, O> 3 tfO ^5 O |g :s d fn rrj S O *i*b|t* COOOCOOo|cO003o6i[osO>OiO ifliftu-JiO O to to O O'OtOt-U-t-t-t- t-'t-OOOOCOCOOOOO pp|cOCS>rHCN|^!p?2oo|prH( b b ]>b ib D I to b ib ib >b i b ib >b -o |-b-b'b-i |tb^-b-i~-|i~-!b-b-t-oo|cbcbcocooococo> i to i coc -i> b- b- i J?- t- h- N. t- cb cb i p^;p^S|ScS2 7**?? jopSrH ISfeS* jt-S 8S 8 ^^^rj.U^'HoLoooooototoo S?^5!|Spo3S|p^^f iSSS S ^4(i-^4*4jb>b>bibibo ? eo-*Aj(4jbu-) tO Oi CN lO CO rH CM -^1 O tO tOtOt-1 t^t^t^t- OirH CM T(< Ip tb-boo'bltotbtot- lOUTMOCOtOtOtOtOtO OtOt>-l~ OrHCbib>b|ib>b>btbitbbtbh- 21 22J22 ! rH 04 CO ill s eocoeoeo|cococoi*i ^^^^i|^^-itib >b ibibibil'b'btbto i>btbtb i >b to to Boys', 430 Camber in girders, 132 Candle balance, 360 ends in photometers, 360 Candles, old, 361 , per gallon, 385 , standard, 360 Cannel, as an enricher, 386 Cantilever type gasholders, 223 Capacities for pumps, 185 of circulating tanks, 192 meters, 321 scrubbers, 195 station meters, 229 Capacity, measures of, 44 Carbide, yield of, 390 Carbon atoms in enrichers, 301 bisulphide, 273 , calorific value of, 156 di-oxide, action of lime on, 272 , causes loss of light, 347 - , description of, 352 in boiler flues, 261 water gas, 394 , per minute of run, 395 produced by gases, 331 lights, 305 , reduction of illuminating power by, 267 , removal of, 271 , testing for, 378 INDEX. escaping unconsumed, 307 , heat energy of, 341 , units from, 244 in coke, 382 furnaces, 241 retorts, 247 sloping retorts, 247 monoxide, diluting effect of, 255 , water in, 394 Carbonic acid, effect on rabbits, 399 Carbonising, 233 at different temperatures, 03 Fixing meters, 321 Flame, gas, cause of luminosity in, 355 temperatures, 354 Flames, effects of pressure on, 356 in rare atmospheres, 308 , oxygen required to support, 357 , theory of formation of, 311 , temperatures of changes in, 353 Flanged connections, dimensions of, 118 Flanges, area of, to girders, 132 for pipes, dimensions of, 289 of cast-iron tanks, 203 , proportions of, 122 to purifiers, 198 Flat plates, strength of, 143 pointing, 74 rolled iron, weight of, 91 Flaws in boiler plates, 175 Flemish bond, 71 Floor joists in basements, 82 retort houses, 154 Floors, loads on, - , safe loads on, 78 Flow of air in pipes, 281 Flue gases in boilers, 261 , proper proportions of, 240 Flues, arrangement of, 157 , blue flame at outlet of, 242 for boilers, 176 gas stoves, 314 , size of, 158 , temperatures in, 154 , vacuum in, 241 448 INDEX. Flux for soldering, 124 Flywheels, safe speed of, 187 Fog in photometer rooms, 358 Footings, 65 Footpaths of tar concrete, 146 Force of explosive mixtures, 329 the wind, 215 water (bursting), 203 pumps, 186 tending to drive off bends, 291 Forcing gas down mains, 321 Formation of cyanogen compounds, 266 Formula, Pole's, Cripps on, 294 Foot, decimals of, 48 Foul main, area of, 160 temperature, 160, 254 Foundations, 64 for boilers, 176 tanks, 202 in water, 65 , pressures on, 65 Fractional distillation, 235 Freezing of water in tanks, 203 mixtures, 337 points, 333 of benzene, 388 French and English gases, comparative prices, 304 words for gas apparatus, 437 Friction, co-efficient of, 186 in condensers, 165 of accumulator ram, 151 to separate tar, 159 Front walls to benches, 155 Frost, action on mortar, 74 in tanks, 279 Fuel, Andrew's patent, 260 , composition of, 382 , consumption per I.H.P., 176 , depth of, 157 , evaporative power of, 259 in generators, 393 of breeze, 317 , petroleum as, 176 , required for water gas, 394 sulphate plant, 405 Fuels, air required for, 346 , combustion of, 259 , space over, 155 , heating power of, 260 , temperature to convert to CO, 240 Furnace efficiency, to estimate, 155 flue seams for boilers, 176 Furnaces, air required in, 155, 240, 244 C in, 241 coal required in, 244 generator, 157 labour required for, 245 regenerative, 157 repair of, 243 temperature, to find, 249 -T water evaporated by, 243 Fusible alloys, melting points of, 250 Fusing point of napthalene, 256 Fusion, latent heats of, 338 , temperatures of, 250 GAIN with gaseous fuel, 241 Galvanised slate nails, 96 Gas, analysis of, 349 and air In burners, 312, 347 , benzene from, 388 , carburine retained by, 386 delivery at high pressure, 285 discharged through mains, rules, 281 , effective heating duty of, 341 engines, 190 , acetylene for, 390 , consumption in, 193 , diagrams, 191 , exhaust, 401 pipes, 191 for tramcars, 192 -, heat units lost in, 193 , horse-power of, 191 , mechanical efficiency of, 191 , meters for, 192 , pressures in, 190, 401 , scavenging, 193 , starting, 193 , stopping, 193 , thermal efficiency of, 166 enriched per gallon of oil, 385 evaporates gasolene, 402 flames for ventilation, 311 for motive power of different illuminating powers, 340 from condensers, analysis of, 256 iron and steam, 380 wood, 387 charcoal, 252 , heat units from, 340 heating before combustion, 308 , illuminating power of, given in table, 426 in gas stove flues, 314 generator furnaces, 240 , lifting power of, 318 , specific heat of, 336 , to obtain specific gravity of, 354 weight of, 354 , velocity of, in chimneys, 179 in railway carriages, 402 leaving retorts, 253 liquor, testing for CO-2, 374 free ammonia, 374 lost from clay retorts, 244 made from cork refuse, 253 by Din sm ore process, 253 from peat, resin, sawdust, 253 mains, depth of, 279 making process, Browne's, 387 meter unions, 320 oxygen required for combustion, 305 passed through sawdust and sulphur. 267 small on lice, 256 , pressures of, 323 Stove notes, 314 supply pipes, 315 suction producers, 403 , supply required or cooking. 31* tubing, weight of, 297 INDEX. 449 Gas valve testing, 292 washed in a tar seal, 253 with mineral oil, 325 works site, 151 Referee's standard burner 43ti notification, 412 Gaseous firing, 157 fuel, gain with, 241 products from combustion, 346 Gases, diffusion of, 279 Gasholder bell, to ascertain weight, 214 , care of, 279 carriages, 224 columns, strength of, 222 contraction of on lifting, 226 Gasholders, cost of, 210, 219 , curbs trussed, 210 , equilibration chains for, 214 , general notes, 210 guides, 220 , spiral, 220 for Dowson gas, 401 in gales, 279 joints, strength of, 225 of cantilever type, 223 , painting, 212, 279 , pressure of, 214 pumps, 209 sheets, rivets required for, 212 side sheets, thickness of, 212 single lift, 210 strains on top sheets, 210 , Wyatt's rules, 225 tanks, 202 , frost in, 279 , to increase weight of, 210 , trussing, 21 2 , weight of, 214 (diagram), 221 Gasolene, 302 evaporated by gas, 402 Gauges, mercury, 357 , pressure, 357 , in decimals of 1 inch, 89 Gearing, rope, 189 Generator for water gas, 393 furnaces, gases in, 240 , gas compression of, 401 gases, proportions of CO jin,242 , heat produced in, 158 setting, 157 Generators, fuel in, 393 , temperatures in, 393 German words for gas apparatus, 437 Girders, area of flanges to, 132 bearing surface for, 132 camber on, 132 cast iron, 138 continuous, 139 relative strength of, 138 thickness of web plates for, 139 wrought iron, notes on, 139 Glass sheet, thickness of and weight of, 77 tube, to bend, 324 G.B. Globes, absorption of light by, 309 Glossary of terms, 437 Glycerine for meters, 321 Governor bell area, 321 cones, 321 Grabs, saving by, 152 Graduating photometer bars, 359 Grains sulphur from grains BaSO* (diagram), 383 Granite, analysis of, 76 piers, safe load on, 75 Grammes, &c., to convert, 58 Grates, heat evolved by, 310 Gravel, safe load on, 75 Grips and cups, 224 Ground area required, 151 , bearing power of, 202 under mains, 291 Grouting in steel tanks, 203 Guide framing notes, 220 rollers, 224 Gun cotton, heat of explosion, 329 Gussets to gasholders, 210 Gutters, fall in, 80 Gyration, least radius of, 141 HALF-round iron, weight of, 130 Handholes in hydraulic mains, 159 Harcourt colour test, 376 Harcourt's pentane unit, 369 Hard coke, to obtain, 244 Hardening tools, colours of, 100 Hartley on testing station meters, 319 Haunching, 229 Head of water, 300 Heat absorbed by air, 243 at exit of chimney, 181, 261 conducting power of solids, 338 , effects of, 247 equivalent, 166 evolved by gas flame, 308 open grates, 316 , expansion, by, 330 from 1 Ib. of different substances, 335 in Peebles retorts, 402 lost by unit of surface, 339 when charging, 244 of combustion of fuels, 259 , to find, 347 retorts, to examine, 234 secondary air, 241 produced in generator, 158 , radiant, 89 required to gasify tar, 402 of different fires, 317 , specific, 88 transmission of, 176 units, 166 evolved by substances, 341 from carbon, 244, 397 gas, 340 hydrogen, 398 generated by lights, 307 lost in gas engines, 193 GO 450 INDEX. Heating and lighting by same gas, 356 coal, to indicate, 232 duty of gas, effective, 341 feed water, 261 gases, analysis of, 395 gas for combustion, 308 power of fuols, 260 ; surface for boilers, 178 - value of carburetted water gas, Dowson gas, 401 Heats, best for cooking, 317 Height of lamps, 309 = lifts, 210 purifiers, 201 Hefner-Alteneck's burner, 370 Hemp ropes, strength of, 109 Heptane, 302, 353 Hexagon, length of side of, 41 High-pressure pipes, thickness of, 289 gas delivery, 285 temperatures, carbonising at, 233 Hill's process, 265 Hod, bricklayer's, measurement, 73 Holes, drilling in mains, 221 , leakage through, 292 Hoop iron in tank walls, 205 , weight of, 127 Hoops to tanks, 205 Horse-power of boilers, 174 Dowson gas, 400 falling water, 87 gas engines, 191 rope gearing, 189 required to pass gas, 10G to raise water, 186 _ -with town gas, 301 Horse-powers, to calculate, 166 Horses, power of, 63 Hot lime sulphided, 274 Hourly make of gas, 237 quality of gas, 238 specific gravity, 237 Housing exhauster plant, 166 Hundredweight, decimals of, 40 Hydraulic cranes, 151 mains, 159 levelling, 159 main liquor analysis, 253 overflows, 159 tar, 253 supports, 159 , temperature in, 254 valves, 161 , water in, 253 water seals in, 160 power, 151 distributing, 151 rams, loss in, 88 pipes, loss of head in, 151 cylinders, thickness of, 151 Hydrochloric acid, normal, 345 Hydrogen, diluting effect of, 255 escaping unconsumed, 307 , heat units from, """ lifting power of, 318 H2S, action of oxide upon, 269 ^, test for, 375 TGNITING point of coals, 2*2 JL Ignition of gas engines, 190 Illuminating agents, relative values of, art?; power by calorific values, -from equal areas of flames, 363 - lost by air, 244 , table giving, 426 value of acetylene, 353 ethane, 353 ethylene, 353 methane, 353 values of hydrocarbons, 355 Impurities in condensed gas, 257 crude gas, 235 gas after scrubbers, 266 Incandescent burners with gas and air, 347 electric lamps, 313 Inch, decimals of, 47 I.H.P., to calculate, 169 Indicating heating of coals, 232 Indicators, to prepare, 843 Inertia, moments of, 136, 144 . Inhalation of adults, 808 | Injecting air into purifiers. 275 oil in water gas plant, 393 Hydrocarbons, amount for enriching, 389 , , temperature of produc- tion, 233 , to absorb, 326 ., illuminating value of, 355 Inlet pipes to holders, 224 Inner lift, stability of, 224 , stays, 211 Inorganic matter in coke, 248 Internal pipe fittings, size of809 Inverted arches, 66 Iron angles, weight of, 91, etc. tees, weight of, 91, etc. bands in concrete tanks, 207 bars in concrete, 209 ; burners and acetylene, 391 chains, strength of, 109 , contraction of, by compression, 213 , expansion of, 213 , flat rolled, weight of, 91 , half-round, weight of, 180 hoop, weight of, 127 joists, 82 pipes, weight of, 114 retorts for tar carbonisation, 251 .round, weight of, 131 , square, weightlof, 131 sheet, weight.of, 124 tanks, 202, 203 testing, 112 tubes, safe pressure on, 174 JET photometer, 261, 857 Joining aluminium, 229 platinum, 229 INDEX. Jointing for ascension pipes, 160 mouthpieces, 154 petroleum pipes, 397 pipes with lead, 292 Joints in dip pipes, 160 gasholders, strength of, 225 stonework, 76 of millboard, 292 pipes, depth of yarn in, 292 weight of lead in, 288 , testing with soap, 292 Joists, iron, 82 rolled iron, diagram of, 134 timber, 82, 137 , safe load on, 86 Joule's law, 166, 340 equivalent of heat, 166 Journals, engine, 186 and space between, 183 KEEPING right tenrperature in puri- fiers, 201 Keys, proportion of, 187 Kindling explosive mixtures, 329 T ABOUR required for furnaces, 245 J.J to carbonise, 244 Laming material, 274 Lamps, height of, 309 Lancashire boilers, 173 , proportions of, 170 Latent heat, of evaporation, 335 fusion, 338 liquefaction, 338 Laths, angle iron, 142 , for slating, distance apart, 79 Latticed standards, resistance of, 223 Layers of material in purifiers, 198 Laying lead, 80 mains, 291 permanent way, 148 slates, 78 Lead jointing, 292 laying, 80 i nails, 96 pipes for services, 292 pipe, weight of, 123 sheet, covering power of, 90 , thickness of, 80 , usual thickness of, 80 , weight of, 80 test papers to prepare, 342 , to unite, 100 , weight of in pipe joints, 288 , white, to test, 77 Leakage in district, 300 through holes in plates, 292 Leak, finding in mains, 292 Leaks, in connections, to find, 194 tanks, 205 Least radius of gyration, 141 Length, measures of, 43 of flame, 356, 399 Length of side of decagon, 41 dodecagon, 41 hexagon, 41 octagon, 41 Levelling hydraulic mains, 150 Liability of water to freeze in tanks, 203 Lifting power of gases, 318 purifiers, 201 Lifts, depth of, 212 Light absorbed by globes, 309 areas covered by, 358 carbon di-oxide produced by, 305 comparative cost of, 313 decomposition by, 360 from standard burner, 369 heat units generated by, 307 lost by addition of air, 347 mechanical equivalent of, 356 minimum required, 307 theory of, 354 velocity of, 356 Lighting and heating by same gas, 356 power of acetylene, 391 table, 309 up water gas plant, 393 Lightning conductors, 181 for chimneys, 159 Lime, absorptive power of, 278, 372 , action on CO 2 and H- 2 S, 272 , caking in purifiers, 270 , combining with water, 271 , earthy matters in, 270 , increase of bulk when slaked, 271 , made from chalk, 270 , quantity required to purify, 270 required for C0 2 , 270 sheds, 198 . slaking before use, 271 testing, 372 , thickness on grids, 271 , water for testing, 342 in, 271 , weight of, 270 , wet, for purifying, 271 Limestone, value of, 270 Limiting explosive mixtures, 329 Limit of heat in settings, 240 weights of wrought iron, 140 Linear expansion, coefficients of, 89 Line, to divide, 64 Lining water gas vessels, 393 Linseed oil, boiled, 77 raw, 77 Liquefaction, latent heats of, 338 Liquid air, density of, 328 fuel, 242 measure, 44 measures, equivalent, 56 [.i-iuids, expansion of, 332 by heat, 338 quor, amount of sulphate from, 404 , analysis of, 264 - freed from CO 2 , 263 from condensers, contents of, 256 in hydraulic mains, 253 scrubbers, 196 GO 2 462 INDEX. Liquor made from coal, 165 , ounce strength of, 375 = , standard test solution for, 343 tanks, 165 , testing for CO- 2 , 374 free ammonia, 374 Lithium hydride, 353 Litmus papers, 342 to prepare, 343 Load on roofs, 78 , safe, on piers, 75 rolled iron joists, 134 Loads, dead, in buildings, 87 , live, on buildings, 87 on floors, 82 Loam earth, resistance of, 204 Locomotives, heated by petroleum, 24- , tractive force of, 14s Logarithms, 1 described, 23 London gas, analysis of, 349 Long measure, 43 pipe condensers, 167 Loss by storage, 279 of ammonia, to prevent, 265 - head in hydraulic pipes, 151 heat in condensers, 164 when charging, 244 gas in purifiers, 267 light through gas travelling, 30] weight by stacking coal, 231 Losses in boilers, engines, and electrici plants, 169 direct fired settings, 239 Lowe oil gas, analysis of, 592 Lubrication for exhausters, 258 Luminosity, cause of, in gas flame, 355 Luminous effect of flame areas, 314 Lutes in purifiers, 198 , steam in, 224 Luting materials, 244 MACHINE belting, 187 stoking, space for, 153 Mahler's calorimeter, 249 Mainlaying, 291 Mains, 281 , coating for, 291 , covered with felt, 291 , depths for, 279 , dimensions of, 286 , drilling holes in, 291 , fall required in, 291 in works, of wrought iron, 165 , small services from, 291 , temperatures in, 300 , testing in district, 291 , with sleepers under, 291 Maintaining flame at constant height, 307 Maintenance of metal tank, 203 Make of gas per hour, 237 liquor, 165 Making oxygen, 276 roads, 146 sulphuric acid, 405 Manilla ropes, strength of, 189 Man power, 63 Man's strength, 228 Manure, sulphate as, 406 Marks on photometer bars, 359 Mariotte's law, 365 Marsh gas, description of, 352 , particulars of, 325 Materials for luting, 244 roof, weight of, 78 required for railway, 148 settings, 15(J weight of, 60 Mathematical tables, 1 Maximum wind pressure, 216 Measurement of coals, 145 coke, 145 Measures and weights, 42 of capacity, 44 length, 43 Measuring pipes, 293 Mechanical efficiency of gas engines, T9I steam engines> 166 equivalent of light, 356. Melting iron, cupolas for, 14A points, 247, 330 of alloys, 250,. 335 elements. 322 metals, 98; 33 solids, 334 Memoranda, electrical, 350. Mending broken pipe, 292 Men employed in carbonising, 245 required for water gas plant, 393 Mercury, comparison of, S& gauges, 257 , pressure of, 299 , weight of, 357 Metals, comparative strength of, 130 weights. 128 , coefficient of expansion of, 334 , effect of heat on, 114 , electrical conductivity of, 98 , melting points of, 334 , safe stresses on, 128 , specific heats of, 334 , weight of square foot of, 128 Methane, description of, 852 , illuminating value of, 353 Meters at high and low pressures, 321 , dry average tests of, 321 , effect of, on illuminating powe: of gas, 321 , fixing, 321 , glycerine for, 321 , for gas engines, 192 , station, 229 , to prevent freezing, 321 , wet, particulars of, 319 , unions for, 320 Methyl orange, to prepare, 343 Metric equivalents, 56 liquid measure, 56 measures of length, 56 Metropolitan Argand burner No. 2, 425- Metropolitan Building Act, 72 Mile, decimals of, 47 INDEX. 453 Millboard joints, 292 Minimum light required, 307 Mixing concrete, 73, 209 gases, 279, 234 puddle, 204 water at different heats, 339 Mixture for stucco, 73 Mixtures, freezing, 337 Moist air in photometer rooms, 358 Moisture in air, 31 i coal, 251 coke, 244 Moments of inertia, 136, 144 Money, to convert to decimals of 1, 45 Monier system, 74 Mortar, 72 , best sand for, 73 , in frost, 74 , strength of, 72 , water required, 73 Morticing, 229 Motive power from acetylene, 390 gases, 194 Motor, cost per horse-power, 318 Mouthpieces, jointing for, 154 , size of, 155 , weight of, 160 , yield per, 157 Multipost gasholder framing, 222 N AILS, copper, weight of, 98 for slating, zinc, 79 , lead, slating, 96 , slate galvanised, 96 Names of gas apparatus in French and German, 437 Napthalene, 310 and cannel, 386 as an enricher, 302 compared with benzene, 387 , description of, 352 , fixing point of, 256 in condensers, 164 gasholder pipes, 279 scrubbers, 262 tar, 409 works, 256 , preventing deposition in works, 256 , tests for, 256 , to clear from condensers, 256 with dry gas, 256 Natural gas, composition of, 351 slopes of earths, 202 Newcastle coal, ash from, 251 Nitrate of soda compared with sulphate, 405 Nitrogen, combination in coal, 384 in coals, 265 for sulphate, 404 reduces light, 347 Noises in exhaust pipes of gas engines. 192 Nominal horse-power, 166 Non-conducting materials, 182 Non-conductors for steam pipes, 184 Normal hydrochloric acid, 345 oxalic acid, 345 sodium carbonate, 345 hydrate, 345 solutions, equivalent, 346 sulphuric acid, 345 Notes, electrical, 350 on boilers, 173 chains, 111 coai stores, 148 gas stoves, 314 guide framing, 220 Pole's formula, 294 pumps, 284 riveting, 108 ropes, 111 ventilation, 311 wrought-iron girders, 132 Notification ol Gas Referees, 412 Numbei of burners required, 311 feet for Id. (diagram), 303 Numbers, to square, 41 Nuts, proportions of, 102 , weight of, 102 OBLIQUE illumination, 307 Octagon, length of side of, 41 Oil engines, 194 for exhausters, 258 gas tar, analysis of, 396 as paint, 277 , water in, 397 linseed boiled and raWj 77 , sperm, light from, 402 Oils, storing, 232 Old candles, 361 Olefiant gas, description of, 352 Olefine series, particulars of, 325 Ordinary joints, weight of lead in, 285 Oscillation in retorts, 247 Otto cycle gas engines, 190 Ounce strength of liquor, 375 Outlet pipes to holders, 224 Oval, area of, 41 Overflow to hydraulic main, 159 Overheating boilers, 175 Overturning of wind and snow, 223 Oxalic acid, normal, 345 Oxidation of sulphur compounds, 274 Oxide, analysis of, 267 , back pressure from, 268 , combining power of, 268 , compared with Weldon mud, 274 , expansion of, 268 , heating when new, 269 in paint, 280 , new, 268 of iron, effect on CSg, 267 paint, 71 purifiers, reaction in, 268 , purifying power of, 268, 373 surface required, 272 , revivifying, 373 sheds, 198 454 INDEX. Oxide, spent, analysis of, 269 for cyanides, 269 testing, 373 , thickness of layers, 268 , to revivify, 268 , value of, when spent, 269 , weight of, 268 Oxidising gasholder sheets, 211 Oxygen added to gas, 385 and ethylene mixed, 387 consumed by lights, 305 , detecting in coal gas, 378 purification, 275 : required by acetylene, benzene, ethylene, marsh gas, 355 for combustion of fuel, 259 305, 32f purification, 276 support combustion, flames, to prepare, 27( PAINT, covering power of, 76 Painting gasholders, 212, 279 gas stoves, 314 purifier covers, 277 Paint, oxide of iron, 77 Paper, drawing, sizes of, 59 Paraffin series, particulars of, 325 Paris, plaster of, 74 Particulars of dry meters, 320 wet meters, 319 Pavements, tar for, 317 Paving, York, weight of, 76 slabs, 74 Peat, gas made from, 253 Pedestal proportions, 186 Peebles oil gas as an enricher, 402 process, 402 , coke from, 402 , gas from tar by, 402 Pens for registering pressure gauges, 319 Pentane, 371, 423 unit, Harcourt's, 369 , ten candle, 420 Percentage of coal in its use, 250 Permanent way work, 148 Peroxide of iron, 373 Perpendicular, to set out, 64 Petroleum, analysis of, 386 , as fuel, 176 furnaces, 244 heated locomotives, 244 lamp, light from, 307 pipes, to joint, 397 tank, to protect, 397 . vapour explosions, 385 Phenanthrene, 353 Photometer bar, divisions of, 358 graduating, 359 discs, 359 with three spots, 359 jet, 357 rooms, moist Uir in, 358 Photometer rooms, ventilation, 358 , shadow, 358 table, the, 422 Photometers with sliding candles, 360 Piers, safe load on, 75 Piles, 64 , safe load on, 75 Pillars of brick and stone, 69 pine, breaking load on. 84 Pine beams, safe load on, 85 pillars, breaking load on, 84 , safe load on, 75 Pintsch system, 402 Pipe, broken, to mend, 292 condensers, 163 , composite, weight of, 123 fittings, internal, size of, 309 flanges, proportions of, 122 joints, depth of yarn in, 292 -, temporary, 292 - , repairing cement, 292 - , casting, 288 - , coatings for, 123, 291 Pipes, contents of, 90 , copper, weight of, 124 - damaged by electricity, 291 - , depth underground, 291 dimensions of, 286 distributing power of (diagram^ 282 drilling holes in, 291 effects *of rough insides, 291 fall required in, 291 for gas stoves, 315 steam heating, 316 in bad soils, 291 lead, weight of, 123 measuring, 296 outside covered with felt, 291 service, coating, 292 testing, 288 weight of, 114 , (diagram), 120 with sleepers under, 291 Pistons, effective pressures on, 169 Pitch for briquettes, 317 pine beams, safe load on, 85 Placing concrete, 209 puddle, 204 Planing purifier plates, 200 Planks, 82 Plant for semi-water gas, 401 Plaster of Paris, 74 Plates, allowance for lap of, 213 , flat, strength of, 143 in tanks, 203 transverse strength of, 140 Platinum, jointing, 229 Pointing, 72 and facing,, 74 , flat and tuck, 74 Pole's formula, notes on, 294 Poor gas deposits iiapthalene, 256 Porosity of stone, 76 Portland cement, use of, 73 stone, analysis of, 70 INDEX. 455 Portland stone piers, safe load on, 75 Position for enriching apparatus, 402 Potassium hydroxide, 344 Pound sterling, decimals of, 45 weight, decimals of, 48 Pounds water heated by gases, 331 various sub- stances, 331 Power from calcium carbide, 176 , hydraulic, 151 of daylight, 307 horses, 63 men, 63 oxide to remove sulphur, 269 puddle to retain water, 204 reflecting heat, 89 the eye, 358 water fall, 88 to dissolve benzene, &c., 388 required to raise water, 184 , results of, 63 Preparing oxygen, 276 Preservation of belting, 187 scaffold cords, 72 timber, 81 Pressure from calcic carbide, 301 washers, 190 in gas engines, 190, 401 puddle tanks, 205 retorts, 247 - water gas shells, 393 gauges, 357 pens for, 319 of air blast in water gas, 393 - column of water, 324 - gasholders, 214 (diagram), 221 - mercury, 299 - snow on gasholders, 214 - water. 299 plane, 206 against a vertical at different levels, 207 on tank sides, 206 217 vapour, 327 wind, 216 at different heights, on circular objects, 218 in different places, 216 on different areas, 217 spheres, 219 boiler furnace tubes, 174 district, 300 flames, 356 foundations, 65 guide columns, 218 retorts, effect of, 244 tank walls, 203 safe on boilers, 174 Pressures thrown by lime purifiers, 271 Preventing boiler incrustations, 261 deposition of napthalene in works, 256 meters freezing, 321 Preventing oscillation in retorts, 165 priming, 261 stopped pipes, 246 Primary air in furnaces, 240 Priming, to prevent, 261 Producer and water gas mixed, 398 gas and flame temperature, 385 , Siemens, 400 gases, composition of, 241 suction, 403 Producers, steam required for, 243 Production of aniline, 409 Products of coal, 255 combustion, 356 from burners, 308 crude oil, 381 distillation, 381 -of coal, 235 tar, 381 works, chimneys, 404 Propane, 353 Proper height of lamps, 309 Properties of circles, 41 Proportions of belts, 188 boilers, 170 bolts and nuts, 102 CO-2 in generator gases, 242 chimneys, 177 crane hooks, 150 enriching gas, to find, 385 keys, 187 pedestals, 186 pipe flanges, 122 riveted joints, 104, 175 rivets, 107 tar concrete, 317 teeth of wheels, 187 tie-rods, 142 treads and risers to stair- washers, 102 Protection areas of lightning conductors, 181 Prussian blue, 196, 276 in cyanogen liquor, 384 Puddle tanks, pressures in, 205 , mixing, 204 , placing, 204 , weight of, 204 Pulleys for rope driving, 188 , rims, width of, 187 Pump notes, 184 Pumps, 166 , capacities of, 185 for gasholders, 209 Punches, 228 Pure air, contents of, 311 Purification by ammonia, 201, 263 Glaus process, 201 ith oxygen, 275 Purified gas, composition of, 277 Lowe oil gas, analysis of, 392 Purifier connections, 198 covers, 201 fastenings, 200 lutes, 19* 456 INDEX. Purifier seals, 148 Purifiers, 197 , area of, 197 for sulphur purification, 197 , height of, 201 in sulphate plant, 404 , lifting, 201 , loss of gas in, 267 Purifying, 267 power of oxide, 268, 373 sheds, 197 value of lime, 372 water gas, 396 Purlins, angle iron, 142 Purity of benzol, 388 Putlogs in scaffolding, 72 Putty for temporary pipe joints, 292 Pyrogallic acid, to prepare, 345 Pyrometers, 249 /DUALITY of bricks, 67 \^ -- gas per hour, 238 Quantity of acetylene from carbide, 391 -- cyanogen obtainable, 276 -- lime for purifying with oxygen, 276 -- riveting in gasholders, 211 sulphur absorbed by oxide, 269 compounds from coal, 273 T) ACK and pinion valves, dimensions of, Radial' rollers, effect of, 211 Radiant heat, 89 Radiating power of solids, 339 Radius, least gyration of, 141 of crowns, 225 protection of lightning con- ductors, 181 Rails, 149 , strength of, 131 Railway carriages, gas in, 402 , materials required for, 148 Rainfall, maximum, 79 per hour, 79 Raising temperature of purifiers, 275 water, power required for, 185 Rags soaked with oil, 326 Rams, hydraulic, 88 Rate of station meters, 229 travel through purifiers, 197 Raw linseed oil, 77 Reaction in oxide purifiers, 268 of cyanides, 196 liquor and sulphuric acid, 404 oxide when revivifying, 269 Reciprocals, 1 Recovering cyanogen, 265 Red litmus paper, to make, 342 lead, setting of, 280 Reduction of temperature of waste gases, Reduction of illuminating power by CO 2 , 267 pressures in pipes, 281 Referees, notification of, 412 Reflecting power of ceiling, 307 solids, 339 radiant heat, Reflection of different substances, 311 Refrigerating coal gas, 401 Regenerative settings, 157 Regulations for testing, 410 Relative carrying capacities of pipes, 285 strength of beams, 138 girders, 138 values of illuminating agents, 305 Removal of ammonia, 196 C0 2 , 271 82 by scrubbers, 263 cyanogen compounds, 277 sulphur compounds, 272 tar, 255 Removing dip pipe seals, 160 tar, 164 Rendering tank walls, 209 Repair of furnaces, 243 Repose, angle of, 62 Residuals from crude gas, 235 Resin, gas made from, 253 Resistance of beams, 136 cohesion of wall, 203 curves, 149 damp sand, 204 earth backing, 203 lattice standards, 223 loam earth, 204 round cast-iron columns, - trains, 149 - web plate standards, 223 - weight of tank walls, 203 to crushing, 68 stones, 75 223 loads, safe, 75 shearing, 106 torsion, 107 traction OH roads, 147 Results of distilling tar, 407 power, 63 Retort, clay, life of, 243 house, area required, 154 chimney, 158 , constructing, 151 drains, 154 , floor joists for, 154 , roof trusses for, 154 houses, compressed air in, 154 , ventilation of, 154 -, width of, 154 Retorts, 153 , carbon in, 247 , circular, 155 , clay, 155 , effect of pressure in, 244 , for Peebles process, 402 , heat of, to examine 234 INDEX, 457 Retorts, iron for tar carbonisation, 251 , oscillation in, 247 , space above coal, 233 around, 154 , temperature in, 254 , through, 155 , velocity of gases in, 234 , yield per square foot, 234 Reversing photometer discs, 359 Revivification of oxide in air, 273 Revivifying oxide, 373 , reaction, 269 Right angles to set out, 64 Rising pipes, curves in, 160 Riveted joints, proportion of, 104, 175 to plates, strength of, 107 Riveting crown sheets to trussing, 211 gasholders, 212 notes, 108 , quantity of, in gasholders, 211 thick to thin plates, 213 Rivets, allowance for waste on, 213 heads, weight of, 106 , proportions of, 107 required for gasholder sheets, 212 , shearing resistance of, 108 strain on, 226 , size of, for boiler plates, 175 plates, 106 strength of, 105 Road making, 146 tramways, 147 Roads, gradients in, 147 Rocks, weight of, 62 Rod- of brickwork, 69 Rods, round, strength of, 130 Rolled joists, diagram, 134 iron, weight of, 91 T-iron, strength of, 142 Rollers radial and tangential, effect of, 211 Roman cement, 74 Roof, area, to calculate, 78 coverings, 79 Roofing, All port's waterproof, 80 , Willesden, 80 Roof materials, weight of, 78 sheeting, corrugated, 98 trusses, height of, in retort house, 154 Roofs, allowance for snow on, 79 , curved, 80 , load on, 78 , wind allowance on, 79 Room heating, 316 temperature, 308 Rope driving pulleys, 188 gearing, 189 Ropes, notes on, 111 , safe working loads on, 112 , strains round pulleys, 112 , strength of, 109 , wire, on pulleys, 232 Round rods, strength of, 130 station meter, dimensions, 230 Rule for correcting for rate of burning of gas, 363 Rule for height of lamps, 309 position of hoops to tanks, 20. r > thickness of tanks, 205 weight of pipes, 115 , to find intensity of light, 310 Rumford photometer, 358 Rusting of wrought iron framing, 220 Rust joint cement, 127 S AFE load on floors, 78 piers, 75 rolled iron joists, 134 timber joists, 86 pressure on boilers, 174 resistance to loads, 75 stresses on metals, 128 Safety, factors of, 89 on stones, 76 tubes in blast mains, 393 valves, 176 Safe working loads on ropes, 112 Salts in tar, 235 Sand and cement, strength of, 72 , best for mortar, 73 , value of in mortar, 72 , in mortar, size of, 73 , resistance of, 204 Saturated hydrocarbons, 325 Saturator, temperature in, 405 Saving by conveyor, 152 grabs, 152 steam jacketing, 168 Sawdust, gas made from, 253 Saws, best rate for, 228 Scaffold cords, to preserve, 72 Scaffolding, 72 Scavenging gas engines, 193 Schneider's heat testing cones, 249 Screw threads, 125 Scrubbers, ammonia removed by, 262 , ammonia at outlet, 2(56 and washers, 195 , boards for, 195 .effects of temperature upon, filled with coke, 195 for water gas, 393 .napthalene in, 262 , surfaces in, 195 , water required in, 262 -, wetting material in, 26? Scrubbing and washing, 262 Seals of purifiers, 198 Seams in furnace flues, 170 Seasoning timber, 81 time required for, 83 Secondary air, distribution, 157 , heat of, 241 in furnaces, 240 warming, 158 Seger's cones, 249 Segment, area of, 41 Semi-water gas, 401 Separating tar by friction, 159 Service pipes, coating, 292 296 458 INDEX. Services, connecting, 296 from small mains, 291 of lead pipe, 292 to photometers, 363 Setting out curves, 147 right angles, 64 Bettings cost of, 156 covering for, 154 direct fired, losses in, 239 for boilers, 176 generator, 157 limit of heat in, 240 materials required for, 156 steam under bars, 243 temperatures in, 241 . walls of, 154 Sewerage, 66 Shadow photometers, 358 Shafts for boilers, 181 Shale oil, distilling, 385 Sheard's tests for NH 3 , CO 2 , H 2 S, 375 Shearing resistance of rivets, 108 to, 106 strain on rivets, 226 Sheet brass, weight of, 124, 130 glass, thickness of, 77 , weight of, 77 iron, weight of, 124 lead, covering power of, 96 , usual thickness, 80 weight of, 80 zinc, weight of, 96 Sheds for purifiers, 197 Shrinkage of castings, 99 Side plates, strains on, 225 sheets of gasholders, thickness of, 21? purifier covers, 201 Siemens producer gas, 400 Simple sulphate plant, 404 Single lift gasholders, 210 Six-hour charges, 238 Size and weight of slates, 79 of brickwork materials, 67 box tinplates, 97 chimney for boilers, 178 connections in works, 162 drawing paper, 59 flues, 158 holders in works, 210 internal pipe fittings, 309 mouthpieces, 155 photometer rooms, 358 purifiers, 197 rivets for boiler plates, 175 plates, 106 sand in mortar, 73 service pipes, 293 stables, 146 Slabs, paving, 74 Slaked lime, weight of, 272 Slaking coke, 244 lime before use, 271 increases bulk, 271 , water required, 201 Slate nails, galvanised, 96 , lead, 96 Slate nails, zinc, 70 Slates, good, to judge, 79 , laying, 78 , sizes and weights, 79 , to test, 79 , weights and sizes, 79 Sleepers under mains, 291 Sliding candle photometers, 360 Sloping retorts, carbon in, 247 Slow condensation, 164 Slopes of earths, 62, 202 Smith's forge, air in, 229 Smooth surfaces to retorts, 155 Snow, allowance for on roofs, 79 , pressure of, on gasholders, 214 , weight of, 214 Soap for testing joints, 292 Socket joints, dimensions of, 289 Sockets, weight of, 290 Sodium carbonate, normal, 345 flames, 357 hydrate, normal, 345 Solar distillate, 396 Soldering, flux for, 124 Solids, melting points of, 334 , power of for conducting heat, 338 Soot from coal fires, 317 Sound, speed of, 88 in air, 328 Space above fuel, 155 around retorts, 154 between bearings for shafts, 183 tire bars, 155 for machine stoking, 153 occupied by coals, 145 for fuel, 260 Spaces, volume of, in concrete, 74 Specific heat, 88 . of air, 241 bodies, 336 fire-clay, 152 metals, 334 346 37H -gravity of bricks, 69 compared with Twaddel, - of benzene, 388 caking coal, 252 carbide, 391 coal to obtain, 380 elements, 322 gases to obtain, 354, ten per cent, acid, 375 water gas, 352 per hour, 237 Speed of condensation, 164 cutting tools, 228 sound, 88 in air, 328 , safe of flywheels, 187 Spent oxide, analysis of, 269 , testing, 373 value of, 269 Spermaceti for candles, 361 Sperm light of oil, 402 , value of gas in, 380 INDEX. 459 Sphere, volume of, 41 ! Stoking boilers, 260 } wind pressure on, 219 J stone, Bath, weight of, 7 Spiral gasholder guides, 220 { pillars, 69 Spoiling gas with too much air in purifl- , porosity of, 76 cation, 275 Spontaneous combustion, 326 Square iron and steel, weight of, 131 Square measure, 43 of a number, 41 roots, 1 Squares, 1 Stability of gas with benzol, 887 hydrocarbons, 325 inner lifts, 224 sulphided lime, 274 Stabling, 146 Stacking coal, 231 coke, 232 Staircases, treads and risers, 80 Standard burner of Gas Referees, 435 candles, 360 f , Carcel, 370 , Hefner- Alteneck's, 370 liquor solution, 343 Pentane, ten candle, 420 Standards, bending moment of, 223 , distortion of, 223 , latticed, resistance of, 273 , strength of, 220 , web plate, resistance of, 223 Starting gas engines, 193 Station meters, capacities of, 229 dimensions, 230 drums, 230 groaning, 319 . rate of working, 229 , testing, Hartley's notes,; Steam, condensation of, 182 [319 ; engine, calorific power, 191 , mechanical efficiency, 166J , water consumption in, 261 for ejecting tar, 242 warming, 315 in lutes, 224 purifiers, 275 jacketing, saving by, 168 pipes, expansion in, 182 for boiler, 182 , thickness of, 182 pressure for water gas, 393 producer, 243 in Dowson producer, 401 steps, 81 work, joints in, 76 .York, weight of, 76 Stones, resistance to crushing. Stopped pipes, to prevent, 246 I Stopping gas engines, 193 I Storage for coals, 145 , loss by, 279 I of materials, 145 | Stores, coal, 145, 149 Storing materials, 231 oils, 232 Stourbridge fire-clay, 152 Strains in gasholders, Wyatt's rules, 225 ropes, 112 on crowns with different rises, 213 side plates, 225 top sheets of gasholders, 210, 211 Strength, breaking, 101 , comparative, of metals, 130 , clastic, 101 , transverse of plates, 140 of a man, 228 belting, 188 boilers, 173 bolts, 103 brick columns, 68 cast iron pipes as girders, 144 cement and sand, 72 chains, lOt) concrete, 75 cylindrical beams, 222 double headed rails, 131 - English bond, 72 flat plates, 143 gasholder columns, 222 joints, 225 tubing, weight of, 297 under bars of settings, 243 Steatite for burning tips, 308 Steel angles, weight of, 91, etc. curbs for gasholders, 211 cylinders, strength of, 171 effect of heat on, 114 joists, breaking weight on, 138 , round and square, weight of, 131 tanks, 203 tees, weight of, 91, etc. , testing, 112 Stiffeners, vertical, 211 Stockn*mming, 205 guide framing, 220 manilla rope gearing, 1S9 mortar, 72 rivets, 105 riveted joints to plates, 107 ropes, 109 round rods, 130 steel cylinders, 171 tank walls, to calculate, 201 T-iron, 142 timber, 82 wrought-iron cylinders, 171 in gasholders, 220 j Stresses safe on metals, 128 Strontium flames, 357 Struts in gasholder framing, 224 , of angle iron or steel, 140 I T-iron or steel, 140 Stucco, mixture for, 73 I Suction gas prod ucers, 403 I pipes for pumps, 184 Sugg's burners, 369 Sulphate, amount from liquor, 404 I as manure, 406 460 INDEX. Sulphate from coal, 404 made in 1894, 405 plant condensers, 404 -, fuel required, 405 -, purifiers, 404 -, simple, 404 - of iron, 373 -, time required to manufacture, 405 Sulphide from hot lime, 274 of lime, 373 Sulphided lime, air with, 273 purifiers, action in, 273 , effect of CO 2 upon, 273 upon, 273 H.,S stability of, 274 Sulphocyanic acid, 277 Sulphur compounds from water gas, 396 , oxidation of, 274 , quantity from coal, removal of, 272 temperature of for- Tank walls, rendering, 209 , resistance of weight of, 203 , thickness at base, 205 of, 203 Tanks, asphalte for, 209 , brick, 205 , details of, 209 , hoops to, 205 for gasholders, 202 , foundations for, 202 , leaks in, 205 for liquor and tar, 165 , sides, pressures of water on, 206 , rules for thickness of cylinder, 20i> , to calculate strength of walls, 207 , wrought iron, thickness of (dia- lation, 244 from damp coal, 233 gas burning, 308 gram), 208 Tar, analysis of, 407 , oil gas, analysis of, 396 and liquor tanks, area of, 165 as fuel, 244 , average yield of, 407 , carbonisation of, 251 , composition of, 407 concrete for footpaths, 146 -, proportions of, 318 in coal, 382 -, estimating, 381 enrichers, 386 gas, 267, 382 lost in lime purifiers, 271 passing to purifiers, 269 Sulphuretted hydrogen, 267 , test for, 375, 428 Sulphuric acid for hydrocarbons, 345 , normal, 345 , to make, 405 Sumpts for tanks, 202 Superficial measure, 43 Superheated steam, 394 Superheaters for boilers, 176 water gas, 39 ) Supply pipes to Argand burners, 308 Supporting hydraulic main, 159 Surface, heat lost by, 339 in scrubbers, 195 Surveying measure, 43 Symbols of elements, 822 TABLE of lighting, 209 , pressures of water against 9, vertical plane, 206 Table photometer, the, 422 Tabular numbers, correcting by, 368, 422 , diagram of, 366 reference, 426 Tangential rollers, effect of, 211 Tank notes, 203 sumpts, 202 wall, backings, 204 walls, 202 , hoop iron in, 205 = , pressures on, 203 constituents, 406 distillates, 406 distilling, results of, 407 firing, advantages of, 242 for painting, 280 from caking coal, 407 pavements, 317 , gas from, by Peebles process, 402 , heat required to gasify, 402 , illuminating compounds in, 252 in hydraulic main, 253 scrubbers, 263 on coals for carbonising, 402 process at Widnes, 252 , products of, 381 , removal of, 164, 255 required to carbonise coal, 242 , salts in, 235 seal, gas washed by, 253 separating by friction, 159 , steam for injecting, 242 tanks, 165 used to fire retorts, 239 , yield of gas from, 252 Tees, flanged, dimensions of, 118 Tee iron, strength of, 142 or steel struts, 140 , weight of, 91, etc. Teeth of wheels, proportions of, 187 Temperature below ground, 66 best in condensers, 255 , correcting for, 365 in ascension pipes, 247, 254 - condensers, 254 , cylinders, 168 flues, 154 foul main, 160, 254 ~ generators, 393 hydraulic main, 254 in purifiers, 275 INDEX. 461 Temperature retorts, 254 rooms, 308 saturator, 405 394 pounds, 244 carbons, 233 373 of Bunsen flames, 357 changes in flames, 353 combustion of gases, 332 decomposition of water formation of sulphur com furnaces, to find, 249 gas en taring purifiers, 26 flames, 354 fusion, 250 production of hydra revivification of oxide 301 volatilisation of benzol water in scrubbers, 262 to convert fuel to CO, V40 Temperatures, colours of different, 248 , in flues, 236 gas engines, 191 mains, 300 settings, 241 Tensile strain on side plates, 225 tank sides, 205 strength of mortar, 72 Tension, expansion of iron by, 213 of ammonia gas, 263 aqueous vapour, 326 belts, 188 Testing benzene, 389 , calorific power, 417 carburetting for, 370 coal, 381 for acetylene, 378 gas liquor for COg, 374 with Argand burners, 367 iron and steel, 112 joints with soap, 292 lime, 372 mains in district, 291 pipes, 288 slates, 79 spent oxide, 373 station meters, Hartley's notes valves, 292 r on oi q white lead, 77 ion, 319 Test for CO 2 , 378 H 2 S, 375, 428 Tests for napthalene, 256 pure water, 261 of axles, 149 coals, 251 fire-bricks, 153 Theory of formation of flames, 312 light, 354 photometers, 358 Thermal efficiency of engines, 166, 194 unit, 166, 340 Thickness at base of tank walls, 205 of ascension pipes, 159 * crown sheets, 226 Thickness of cylinder in tanks, 205 engine cylinders, 168 hydraulic cylinders, 151 layers in purifiers, 201 pipes for high pressures, 289 sheet lead, 80 glass, 77 sheets of wrought-iron tanks (diagram), 208 side sheets of gasholders, 212 steam pipes, 182 tank walls, 402 tin plates, 96 11s, 72 walls, web plates for girders, 139 Threads for bolts, Whitworth, 126 gas pipes, 298 screw, 125 Three lift gasholders, 210 Through retorts, 155 Tie-rods in coal stores, 146 , proportions of, 142 to benches, 154 Timber, 81 joists, 82 , safe load on, 86 , preserving, 81 , safe load on, 82 , seasoning, 81 , strength of, 82 Time of contact in purifiers, 197 required for seasoning timber, 83 to charge, 246 make sulphate, 405 to start water .gas plant, 394 Tin plates, thickness of, 96 , box, sizes and weights, 97 tubes, weight of, 124 To estimate furnace efficiency, 155 save fuel, 241 test heats in water gas plant, 393 Ton, decimals of, 49 Too much air in purification, 274 Top sheets of gasholders, strains on, 210 Torsion, resistance to, 107 Tower scrubbers, 195 , effect of cold on, 262 foxicity of acetylene, 391 Traction resistance on roads, 147 force of locomotives, 148 Trains, resistance of, 149 framcars, gas engines for, 192 framways on roads, 147 Prap sand for mortar, 73 transmission of gas through pipes, heat, 175 'ransverse strength of plates, 140 gravel in flues, 157 'reads and risers to staircases, 80 Mangles in guide framing, 220 'rigonometrical terms, 41 'roy weight, 42 'runk mains, 292 'russed holder curbs, 210 Trussing gasholders, 212 Tubes, block tin, weight f, 124 462 INDEX. Tuck pointing, 74 Turned and bored pipes, advantages of, , dimensions of, WALLS for coal stores, 146 of settings, 154 tanks, 202 200 Turmeric paper, to make, 342 Twaddel, 264 , compared with specific gravity, , to reduce to ounce strength, 264 TTNACCOUNTED for gas, 301 U Uneven charging, 233 Unions for gas meters, 320 Unit of heat, 166 Uniting lead, 100 Units, electric, 89 of light, Harcourt's, 369 Unloading materials, 145 Use of Portland cement, 73 sand in mortar, 72 VACUUM in chimneys, 159 waste gas flues, 241 Value of acetylene, 390 chalk, 270 explosive mixtures, 193 gas in sperm, 380 spent oxide, 269 Values of different quality gases for eva- porating, 356 gases for lighting and heating, 356 motive power, 194 Valves, boxing round in works, 165 , dimensions of, 293 for hydraulic mains, 161 in purifier house, 201 , safety, 176 to condensers, 164 , testing, 292 Van Steenberg's process, 399 Vaporising benzol, temperature for, 387 Vapour tension of benzene, 387 Varnish, covering power of, 77 Velocity in exhaust pipes, 182 steam pipes, 182 of diffusion, 279 gases in chimneys, 179 retorts, 234 light, 356 water, 151 wind, 216 Ventilating flue, chimney as, 308 Ventilation notes, 311 of coals, 145 photometer rooms, 358 retort houses, 154 Vertical sheer on standards, 224 stiffeners, 211 Visibility of lights at distances, 310 Vitiation of air by acetylene, benzene, etliylene, marsh gas, 355 lights, 305 Volume of one pound of air, 327 sphere, 41 , thickness of, 72 to fronts of benches, 155 Warming by steam, 315 secondary air, 158 Washers and scrubbers, 195 for petroleum pipes, 397 , pressures thrown by, 196 , proportions of, 102 -, weight of, 103 Washing and scrubbing, 262 gas with mineral oil, 325 Waste gases, reduction in temperature of, 243 Water, absorptive power of, 374 , acetylene absorbed by, 391 and producer gas mixed, 398 consumption in steam engines, distribution in scrubbers, 195 evaporated by fuels, 259 furnaces, 155, 243 261 -, evaporation of, 332 -, expansion and weight of, 333 of when freezing, 337 fall, power of, 88 for condensing water gas, from carbon, 394 gas analysis, 392, 395 , blast mains for, 393 , blowers for, 393 , CO 2 in, 394 carburettor, 393 , composition of, 351 condenser, 393 , cost of, 399 , enriching value of, 396 , fuel required for, 394 generator, 393 , oil required for, 394 plant, explosions in, 394 , lighting up, 394 , men required for, 393 , time to start, 394 , to test heats in, 393 production, equation of, 398 purification, 396 scrubber, 393 , steam pressure for, 393 , sulphur compounds in, 396 superheater, 393 with anthracite coal, 398 heated through plates, 317 in ash-pans, 243 hydraulic mains, 253 lime, 271 oil gas tar, 396 oxide, 267 scrubber, temperature of, 262 mixing at different heats, 339 , pounds heated by gases, 331 various sub- stances, 331 , power of absorption, 196 INDEX. 463 Water, pressure of, 299, 323, 324 produced by carbonisation., 251 , pure, tests for, 261 required for concrete, 74 cooling gas engines, 192 mortar, 73 in scrubbers, 196, 262 to slake coke, 244 lime, 201, 271 seal in hydraulic mains, 160 , specific heat of, 337 vapour, pressure of, 327 , velocity of, 151 yielded by coal, 165 Water-logged earth backing, 203 Watertight concrete, 207 Water-tube boilers, coke fired, 175 condensers, 163 Water-tubing, weight of, 297 Watts, electric, 89 Web plates for girders, 139 Wedgewood's pyrometers, 248 Weight, loss of, by stacking coal, 231 of aqueous vapour, 327 ascension pipes, 160 Bath stone, 76 bell of holder, 212 block tin tubes, 124 bolt heads, 102 brickwork, 67, 69 cast-iron pipes, 114, 281 coke, 145 composite pipe, 123 connections, 116, copper nails, 98 pipes, 124 corrugated iron, 98 curb, 224 dry air, 328 earths, 62 felt, 80 fire-bricks, 68 fire-clay blocks, 153 Weight of sheet braes, 124, 130 sheet glass, 77 . iron, 124 lead, 80 slaked lime, 272 snow, 214 sockets, 290 square foot of metals, 128 tinplates, box, 97 various coals, 145 washers, 103 water, 323 wrought-iron bridges, 141 , tubes, 297 yarn, 288 York paving, 76 zinc sheeting, 96 Weights and measures, 42 sizes of slates, 79 , comparative, of metals, 128 Weldon mud, analysis of, 274 compared with oxide, 274 constituents of, 274 Wet coal causes napthalene, 256 lime for purifying, 271 meters, particulars of, 319 Wetted surface in standard washers, 262 Wetting material in scrubbers, 262 ; oxide with ainmoniacal liquor, Wicks of standard candles, 360 Wide furnaces, 242 Width of belts, 190 retort houses, 154 - gases, to obtain, 354 gasholder bell, to ascertain, 214 Widths of rims of pulleys, 187 Willesden roofing, 80 Wind allowance on roofs, 79 , force of, 215 pressures at different heights, 217 in different places, 216 on chimneys, 179 different areas, 217 sphere, 219 circular objects, 218 gasholders, 214 (diagram), 221 to increase, 210 half-round iron, 130 hoop iron, 127 lead in ordinary joints, 288 pipes, -- materials, 60 mercury, 357 mouthpieces, 160 nuts, 102 oxide, 268 pipes (diagram), 120 , rule for, 115 puddle, 204 rivet heads, 106 rocks, 62 rolled iron, 91 roof materials, 78 T ; round and square iron and stael, 131 of, 216 , velocity of, 216 Wire gauges in decimals of 1 inch, 89 Wire ropes on pulleys, 232 , strength of, 109 Wheels, proportions of teeth, 187 White lead, 77 , effect of sulphur on, 77 , setting, 280 to test, 77 Whitworth threads for screws, 125 gas pipes, 298 Wood changing to coal, 381 charcoal, gas from, 252 gas, 252, 387 Wooden joists, 137 ! troughs for services, 296 I Work of bricklayer, 72 ' Workshop area, 228 floors, loads on, 82 notes, 228 . Works mains in wrought iron, 165 I Wrought-iron bridges, weight of, 141 464 INDEX. Wrought-iron cylinders, strength of, 171 , effect of heat on, 114 girders, notes on, 132 limits of weights of, 140 tanks, thickness of (dia- gram), 208 tube, weight of, 297 works mains, 165 Wyatt's rules for strains in gasholders, 225 TARN, depth of, in pipe joints, 292 required for joints, 288 Year, decimals of, 47 Yielding of gasholder framing, 220 Yield of carbide, 390 ammonia, 262 gas from tar, 252 with exhauster, 167 tar average, 407 per cent., 255 per mouthpiece, 157 square foot of retorts, 234 York paving, weight of, 7( stone, weight of, 76 17 1 NO sheeting, weight of, 9(5 /J slating nails, 79 THE END. BBADBUBY, AONEW.. & CO. LD., PB1NTEBB, LONDON AND TONBBIDGE. ADVERTISEMENTS. G. E. HH ADVERTISEMENTS. " THE GAS WORLD." Published every Saturday. Price 4d. CHE GAS WORLD is the most readable and up-to-date of Gas Journals. 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