196 THE COLLIERY GUARDIAN. January 22, 1915. coking plants in Great Britain, giving the names of places where such plants have been erected, and the number and type of by-product ovens used. The Engineering Standards Committee have issued revised lists of British standard rolled sections. As regards the modifications, four unequal angles, three bulb angles, and two zed bars have been added to the lists, all of which are in demand primarily for ship- building purposes. It has not been found practicable to delete more than one standard section from the lists, as those sizes which are not now required for shipbuilding are considered essential for bridge and underframe work. Certain reductions have also been made in the minimum web thicknesses of the bulb angles and channels, with a view of producing more economical forms of sections. The specification may be obtained at the price of 2s. net from Messrs. Crosby Lockwood and Son (7, Stationers’ Hall-court, E.C.), or from the Offices of the Committee (28, Victoria-street, S.W.). The Practical Electrician's Pocket Book for 1915, which is edited by H. T. Crewe, and published by Messrs. S. Rentell and Company Limited (36, Maiden- lane, W.C.), is the oldest of the electrical diaries. Con- taining over 600 pages, the net cost is only Is. Amongst the new sections are two on “ Electricity in Mines ” and ” Distributing Systems ” by Mr. R. E. Neale. COKE PRODUCTION IN THE UNITED STATES’ According to the return for 1913, by Mr. E. W. Parker, of the United States Geological Survey, the production of coke in that year exceeded all previous records, both in quantity and in value, the actual amount being 46,299,530 short tons, valued at $128,922,273, an increase of 5*3 per cent, in quantity and 15-3 per cent, in value. The principal reason assigned for the higher value per ton is the notable increase in the production of retort oven coke; which accounted for nearly 70 per cent, of the total increase in 1913, 12,714,700 tons, valued at $48,637,852, were made in this type of oven. Thus retort coke fetched $3-82 per ton, as against $2-39 in the case of beehive coke. The number of ovens and retorts in blast during the whole or a portion of 1913 was 72,008, of which 5,531 were retorts; the average value per oven of the coke and by-products produced at retort ovens was $11,854, or nearly 10 times the average value of the beehive production. The new ovens in course of construction at close of 1913 were 1,321, of which 504 were retorts and 817 beehive. The tendency to consolidation into larger units is exem- plified by the steady decrease in the number of separate coke making establishments since 1909; at the close of that year there were 579 such establishments in the United States; at the end of 1913 the number was 551. There were six new plants, with a total of 434 ovens, under construc- tion at the close of 1913, and three of these, with a total of 214 ovens, were retort oven plants. The following figures relate to the industry in 1913 and 1912 .. _________________________________________________________________________________________________________________________________________________________________________ BOOK NOTICES. Great Colliery Explosions and their Means of Prevention. By W. Galloway, D.Sc. pp. 130, 9 in. x 5£ in.; illus. _________ London : The Colliery Guardian Company Limited. This volume is a reprint of papers contributed by the author to various publications not always easily acces- sible, and as they cover a period of about 50 years, and date from the earliest days of the coal dust controversy, it is extremely convenient to have them arranged in chronological order in a single volume. To a great many readers of the Colliery Guardian Dr. Galloway’s work in connection with colliery explosion® will doubtless be familiar, but probably few have been in a position to trace the sequence of events which led to his adoption and experimental proof of the view that coal dust and air can form an explosive combination even in the absence of inflammable gas. When, in 1875, M. Vital, in France, came to the conclusion that finely divided coal dust was alone capable of causing explosions in collieries, Dr. Galloway was at first inclined to reject this hypothesis, and it was only after six years of experimental research that he came gradually to accept M. Vital’s view, which, however, he placed upon an entirely new footing, supported as it was by direct experiment. The description given by Dr. Galloway in the Proceedings of the Royal Society of his experimental ____________________________ gallery at Llwynypia Colliery was unfortunately greatly curtailed in publication, but the author has now given us a full reprint of the original MS. preserved in the archives of the Royal Society, from which it is clear that Dr. Galloway was the pioneer of large scale explosion experiments. His gallery in this case was of wood, being 126 ft. long and 2 ft. square inside, with an explosion chamber, 6 ft. long, of cylindrical shape, 2 ft. in diameter. When contrasted with the large gallery at Eskmeals, this apparatus may seem quite a small affair, but carried out as they were 30 years ago on his own initiative, these experiments deserve to rank as classics in the literature of coal mining. The full history of the evolution of the coal dust theory has not yet been written. We are not yet, indeed, at the end of the business of finding the perfect preventive of colliery explosions; but future writers on this question will be deeply grateful to Dr. Galloway for having facilitated their labours by the publication of this volume, which is a record of a life’s work in the investigation of the causes of mine disasters. The Mine Wagon and its Lubrication. By Caleb Pamely. vii. 4- 106 pp.; 6J in. x 10 in.; 132 figs. London : Crosby Lockwood and Son. Price, 7s. 6d. net. Probably no piece of colliery equipment is so impor- tant or varies so much as the ordinary mine wagon, as they are termed in the Welsh collieries, or boxes, tubs, corves, or hutches, in other districts. We have often wondered why some attempt at standardisation has not been made, and whether it would pay to build a really well-designed and thoroughly put together coal tub on sound scientific lines, with a view of cheapening the cost of production and eliminating friction; but after due consideration of all the varying mining conditions— especially with a legal eight hour day—one has to admit that the problem is one full of difficulties. The present work is divided into two chapters, one dealing with the mine wagon, and the second with its lubrication, but seeing that under the Coal Mines Act, after December 16, 1916, in dry and dusty mines, “ all tubs shall be so constructed and maintained as to ... prevent, as far as practicable, coal dust escaping through the sides, ends, or floors of the tubs,” one would have thought the author would have given considerable attention to this matter, but though several designs of tubs are described and illustrated, this important question does not appear to have much attention. Neither is the principle of the design and construction of a coal tub on the basis of standardisation dealt with, the author being content to describe examples such as are in actual use in different colliery districts. Again, the second chapter deals for the most part with mere descriptions of well-known “ tub greasers,” ending up with the description of two or three ” self-lubricating ” wheels and axles, but the merits of ” oil ” or ” grease ” lubrication are not dealt with. The work, however, will no doubt prove useful as a compilation of the different types of mine wagons and ” greasers ”—and more especially to those who are searching for information with a view to designing a wagon for use in new mines, as most of the examples given are fully dimensioned. Further, the notes on ” friction ” and the “ setting out of gradients of tub roads ” should also prove of value, and in this respect this may be looked upon as a handy book for reference. The “ Gas World ” Year Book, 1915. Edited by John Douglas. 225 pp. London : Offices of The Gas World. Price, 7s. 6d. This “ Year Book ” contains, besides technical infor- mation compiled for the use of those administering gas undertakings, a directory of the gas undertakings in the British Empire, giving names of officials, annual make ____________________________ of gas, price of gas, etc. Among the additional items of information given in this year’s directory is the calorific value of the gas, where this is recorded by the undertakings. There are 1,235 gas undertakings in England and Wales, 256 in Scotland, 110 in Ireland, 163 in Australasia, 57 in Canada, and 15 in other British possessions; in addition, there are 18 British companies owning gas works on the Continent and in other parts of the world. In England there are 1,002 gas works owned by companies and only 233 by local authorities; in Scotland, 195, against 61; and in Ireland, 84, against 26. The “ Year Book ” also includes a list of by-product ABSTRACTS OF PATENT SPECIFICATIONS RECENTLY ACCEPTED. 14188 (1914). Improvements in Underground Conveyors for the Transmission of Coal to Various Parts of a Mine or Pit. S. Hare, of Howlish Hall, Bishop Auckland, Durham. —Consists of that type of bogie having sides and ends built up on a frame, a number of doors at the bottom fixed to movable axles operating in the frame, a curved bow to each door at the bottom and a flat curved iron fixed between the rails for closing the doors as the bogie travels along the track thereby locking the doors by means of quadrant levers and catches, with lifting catches, a long flat rod held by clips having stud® and a male screw at its end working in a frame operated by a hand wheel. Also quadrant levers fixed to the movable axles for locking the catches when the doors are closed. The coal or other mineral is discharged by means of one or more doors fitted to the bottom of the bogie. These said doors are allowed to automatically open by means of a catch, the bottom of which comes in contact with an iron frame fitted on the side of the track, and just above the tub or wagon into which the coal or other mineral is discharged. When the catch is lifted the quadrant levers are released, and the coal forces the bottom doors open, and is discharged into the empty tub or wagon standing below the bogie. As the bogie passes on the doors are raised into position by the curved bow fixed to each door on the underside coming into contact with a piece of flat curved iron fixed between the rails on which the bogie runs. In the event of any door or doors not becoming properly and automatically secured, a long flat rod with a screw thread at the end is provided, and by means of studs fixed close to each quadrant lever any door or doors can be lifted into position. The studs are fixed to the long flat rod above described. Fig. 1 is the side eleva- tion of the bogie; fig. 2 is a plan of the top of the bogie; fig. 4 is one-half in section on line A. B of fig. 3, and the other half an end elevation; and fig. 5 is a part of the side elevation. Figs. 3,4, and 5 are drawn to an enlarged scale. (Three claims.) 14568 (1914). Improvements Relating to Conveyors for Use in Coal Mines. J. L. Kershaw, of Fairlands, Barnes- road, Castleford, Yorkshire. — Coal from ” stables ” or “ cutting corners ” has heretofore had to be removed by hand. According to this invention, this coal is removed and loaded into the tubs by a short conveyor operated from the main conveyor or the mechanism driving it. In order to transmit the power to the short conveyor, the following device is employed. The device consists of two parts, each having a central column similar to an ordinary screw jack, the ends of which firmly butt against the floor and roof. Working loose on the column is a sleeve, to the upper part of which is fixed an arm connected to the sleeve by a screw, Number of establishments ... Ovens built................... Ovens building....................... Coal used.........(short tons) Yield per cent................ Coke produced ...(short tons) Total value of coke........... Average value per ton ....... Production of by - product coke ... ........(short tons) Value of ditto ............... Output of by-products : Gas .......(M. cubic feet) Tar.................(gals.) Ammonia, sulphate or reduced to equivalent in sulphate (lb.) Ammonia liquor __........(gals.) Anhydrous ammonia.....(lb.) Total value of by-products ... 1912. 559 102,230 2,783 65,577,862 67*1 43,983,599 $111,805,113 $2-54 102,650 1,321 69,239,190 66-9 46,299,530 $128,922,273 $2-78 12,714,700 $48,637,852 64,553,941 115,145,025 173,342,349 4,102,448 28)663,936 $16,925,941 11,115,164 $42,632,930 54,491,248 94,306,583 95,275,545 5,502,403 26,672,474 $14,343,795 Fiy 1 The gas included above is the “ surplus ” not consumed in the coking process. The average value of all the surplus gas in 1913 was 8-8c. per 1,000 cu. ft., but where this is used by works the value is sometimes placed as low as 3c., and the lower value of gas produced since 1909 is due largely to the operations of ovens connected with iron and steel works at Corey, Woodward, and Ensley, in Alabama; Joliet, in Illinois; Gary, in Indiana; Ashland, in Kentucky; Sparrows Point, in Maryland; Buffalo and Solvay, in New York; Dunbar, South Sharon, Steelton, and Lebanon, in Pennsylvania; and Benwood, in West Virginia. This factor represents about 70 per cent, of the total production. The following table shows the kinds of by-product ovens built or building at the close of 1913 :— so that its position can be adjusted. The upper arms of the two parts are connected together by a rope or rod, so that the two sleeves turn together. The main conveyor may be of any ordinary type in which the reciprocating motion is given by alternately pulling and releasing a rope connected to one arm of a bell crank lever fixed to the bottom of the sleeve of one of the parts, the other arm of the .bell crank lever being connected to the conveyor. The short conveyor is connected to an arm fixed to the lower part of the sleeve of the other part. Fig. 1 is a diagrammatic vertical section parallel to a face being worked by hand, and fig. 2 is a diagrammatic plan. Fig. 3 is a diagrammatic plan of a face being worked by a coal cutting machine. Fig. 4 is a sectional elevation of the first part of the device. Fig. 6 is a sectional elevation of the second part of the device. (One claim.) 15561 (1914). Improvements in Projectors for Coal and like Solid Materials. W. G. Gibbons, of 32, Victoria-street, London, S.W., and W. J. Jenkins and Company Limited, of Beehive Works, Retford, Nottinghamshire. — Relates to projectors for coal and similar solid materials of the type comprising an endless band or apron passing around pulleys and below a hopper which feeds the coal or other material between the flanges of a pulley on to the apron, and has for its object an improved. construction, whereby the. machine shall be enabled to withstand shocks from, for example, extra large lumps of coal, and so that the projector shall be specially applicable for bunkering coal on board ship or otherwise. According to this invention, one of the jockey pulleys, over which the band or apron passes, is mounted in resilient bearings that give under sudden or excessive Semet-Solvay Built. 1,537 Building. ... 152 United Otto 2,186 — Rothberg 281 — Koppers 1,361 334 Didier 300 — Klonne 22 Roberts-Mass 1 — Wilputte — 18 It is interesting to note that the coal tar products imported into the United States amounted approximately to $10,000,000 annually; in 1913 the total value was $10,962,828, of which colours and dyes made up nearly 80 per cent. On the total duty was obtained to the amount of $2,323,729, and the value by the time these products reach the consumer is probably between $18,000,000 and $20,000,000. Hull Coal Exports.—The official return of the exports of coal from Hull to foreign countries for the week ending Tuesday, January 12, 1915, is as follows :—Aarhus, 1,728 tons; Amsterdam, 319; Buenos Ayres, 3,280; Christiania, 1,313; Copenhagen, 208; Calais, 2,284; Dunkirk, 1,834; Dieppe, 864; Genoa, 9,581; Havre, 401; Harlingen, 596; Larvik, 405; Leghorn, 1,096; Monte Video, 4,435; Norr- koping, 1,648; Rouen, 7,192; Rotterdam, 298; Stockholm, 2,226; Treport, 545—total, 40,253 tons. The above figures do not include bunker coal, shipments for the British Admiralty, nor the Allies’ Governments. Corresponding period January 1914—total, 60,347 tons.