170 THE COLLIERY GUARDIAN July 23, 1915. CURRENT SCIENCE AND TECHNOLOGY. The Use of Blastfurnace Gas in Belgium. At the recent meeting of the Iron and Steel Institute? an interesting paper was read by Prof. H. Hubert, of Liege University, recording the progress in the design of large blastfurnace gas engines, with special reference to Belgian practice. After a valuable historical review, Prof. Hubert recalls that it was the Cockerill Company at Seraing which ventured to build, in 1897, the first large blastfurnace gas engine, developing 200-horse power, and shortly afterwards, in 1900, the company obtained the Grand Prize at the Paris Exhibition for a single-cylinder 4-cycle 600-horse power engine. “ At a period when the writers of a certain other nation,” says Prof. Hubert, “ are unjustly challenging the part played by Belgium in the direct utilisation of gas furnaces,” it is well to repeat the facts. Although the Hoerde Works carried out tests on the same lines shortly after those at the Cockerill Company and put into operation a two-cycle Oechelhaiiser engine of 120-horse power, in 1896, and, two years later, a 600-horse power engine of the same type with two cylinders, the Deutz Company had built for the Paris Exhibition, in 1900, a 500-horse power engine which preserved the four-cylinder type, so that in reality each of the cylinders only developed 125-horse power. For a long time the Deutz Company only followed the Cockerill Company from afar. The latter company has now introduced a new type of horizontal gas engine, a characteristic feature of which is the abandonment of the forged crank-shaft and the reversion to the simple built-up crank, which had been employed by Lenoir, and likewise by Otto, in their earlier machines. The disadvantages of the forged crank shaft are aggravated when the engine is subjected, as often happens in the industrial regions in Belgium, to the influence of surface subsidences caused by the working of coal mines. Largely for this reason the Cockerill Company have abandoned the bent crank- shaft in favour of the shaft with an overhung built- up crank. It is noted that American builders had already adopted this method of construction. Another feature of the Cockerill engine is an exceedingly strong bed-plate. For the more powerful types, and, in par- ticular, for the 7,000 effective-horse-power engine recently installed in the Cockerill Company’s power- house, the bed-plate, which weighs 75 tons, is in two parts, the heavier of which weighs 50 tons. The shape of the cylinders has also been improved, the size of the water chambers being increased, whilst the cylinder walls are better able to withstand the stresses arising from the differences in temperature between the outer casing and the interior cylinder. The piston is built up of two parts bolted to a ring forged on the piston-rod, the piston thus always acting direct by pressure on the rod.; an average pressure can be obtained of 78 lb. per square inch, while it is possible to secure a high compression, which ensures a high thermal efficiency and reduces the gas consumption. In the new system the mixture valve alone opens at the commencement of the piston stroke, so that a gradually increasing vacuum is produced in the cylinder. At a period determined by the governor, a lever which controls the opening of the two air and gas-valves, and which is held motionless by a stop, while pressed upon by the driving-lever of the mixture valve, is freed by means of a special cam. It is then brought into motion by the action of the vacuum which has been produced in a litter cylinder interposed in the rod, which connects the two valves, and it suddenly opens the two air and gas-valves, the hollow spindles of which are traversed by the spindle of the mixture valve. The air and the gas rush into the cylinder with a speed which is greater the lower the pressure, and ensures at atmospheric pressure its complete filling. The Cockerill Company is the only firm of makers employing trip-valve gear. In the case of blowing engines, the Cockerill Company have adopted a new system of governing. The mean speed may be adjusted as required to 64, 101, 136 and 171 revolutions per minute, and in these conditions the speed of the engine may be varied, by governing, within 50, 24, 16 and 11 per cent, respectively of the mean speed. The principal demensions of the different models from which the latest types of the Cockerill Company’s engines are built are as follow :— Effective horse-power. Revolutions Diameter Stroke per minute, of pistons, of pistons, Two Four Average. In. In. cylinders. 960 . cylinders. .. 2,000 ... 115 .. 27*6 ... 47*2 1,250 . .. 2,500 ... 107 .. . 31*5 ... 51’1 1,600 .. .. 3,300 ... 107 .. . 35*4 ... 51*1 2,000 . .. 4,130 ... 100 .. . 39*4 ... 55*1 2,400 .. .. 5,000 ... 100 .. . 43*3 ... 55*1 2,825 . .. 5,650 94 .. . 47*2 ... 59*0 3,400 .. .. 7,000 94 .. . 51*1 ... 59*0 3,200 .< .. 8,000 90 .. . 55*1 ... 63*0 The gas consumption guaranteed for this type motor corresponds to 7,580 B.Th.U. (1,910 calories) per indicated horse-power-hour and to 8,530 B.Th.U. (2,150 calories) per effective horse-power-hour. The mechanical efficiency is about 89 per cent. Another Marine Band in South Lancashire Coal Measures. Dr. Sherlock records in the Geological Magazine for July the discovery of a third marine band in the South Lancashire coal field. The late Prof. A. H. Green had previously found a marine band in the banks of the Tame, near Ashton-under-Lyne, and the late George Wild had discovered the same band at Ashton Moss Colliery, about 750 ft. above the Great Mine. Mr. Herbert Bolton also states that the Cali- fornian or Thin bed of Fulledge Colliery, Burnley, 410 ft. above the Arley Mine, is a marine horizon. The marine band mentioned by Mr. Gerrard, in his presidential address to the Manchester Geological and Mining Society in 1904, as occurring at Victoria Colliery, Standish, is believed by him to belong to the lower coal measures. The marine band now described by Dr. Sherlock belongs to the middle coal measures. The fossils were discovered in the tip heap of the Alexandra Colliery, St. Helens. The horizon is believed to be somewhere between the Little Delph and the Ravenhead Main coal, and is probably to be referred to the roof of the Little Delph (Arley Mine). Amongs t the recognisable fossils &xeEterinopecten papyraceus (J. Sow). Goniatites and fish remains, including a fine specimen of Elonichthys aitkeni (Traquair). Dr. She flock states that the specimens will be deposited in the St. Helens Corporation Museum. Determination of Nitrogen in Coal and Coke. To obviate the drawbacks attending the modified Kjeldahl and other methods proposed for determining nitrogen in coal and coke, Simmerzbach and Sommer (Stahl und Eisen) have adopted a method based on that of Dumas, the substance under examination being burned in a Heraeus furnace in presence of cupric oxide. The fuel is powdered so as to pass through a sieve with 100 meshes to the inch ; and copper oxide, in the state of wire, is reduced to an equally fine state of division in a steel mortar, after which it is calcined in a muffle, with admission of air to complete the oxidation, and is re-crushed if necessary. The powdered fuel and copper oxide are friturated together, about one gram of the former being taken and 26-27 grams of the latter (i.e., about double the theoretical amount needed for the combustion of the fuel); and the mixture is placed in two glazed porcelain boats, which are then inserted in the combustion tube, from which the air is expelled by a current of carbon dioxide. Here they are heated to 800 0. by a Heraeus furnace, which can be slid on rollers so as to heat the whole length of the boats. The pro- ducts of combustion are passed through a Schiff tube charged with caustic potash, which retains the CO2 and allows the nitrogen to collect in the top of the tube, whence it can be transferred to a gas burette. Here it receives an addition of oxygen to oxidise the nitric oxide present into betroxide, which is eliminated by treatment with ammonia, ammonium nitrate and nitrate being formed. The difference between the volume of the collected gas before and after this oxidation treatment gives the volume of true nitrogen from the fuel. The values obtained are considerably higher than those furnished by other methods, the difference being as much as 55 per cent, in some cases, for coal, and up to 27 per cent, for coke. These results, if confirmed, are calculated to prove highly important to the coking industry, more particularly since the figures indicate that the percentage recovery of ammonia from coal is not nearly so high as hitherto assumed, and corresponds to only 8 to 15 per cent, of the nitrogen in the coal, in- stead of 12 to 20 per cent. Coal Prices and Gas Yields. In his address to the members of the Waverley Asso- ciation of Gas Managers recently, Mr. Cuthbert Hamil- ton adduced some interesting statistics, compiled as the average from theaccountsof fifteen corporation gasworks in Scotland, to support his conclusion that there was little advantage in paying a higher price for coal in order to obtain a slightly higher yield of gas. The figures are given by the Gas World as follow :— 1. Gas made per ton of coal ........ 10,201 cu. ft. 2. Gas sold ,, ,, 9,459 ,, 3. Coke „ „ ,, 9'34 cwt. 4. Tar ,, ,, „ 11'4 gals. 5. Ammoniacal liquor ,, (10 oz.).... 35'6 ,, 6. Sulphate (lb. per ton).. 26'3 lb. Average of manufacturing charges :— Per 1,000 cu. ft. sold.. Per ton. d. 1. Coal and equivalent ... 14s. 8d. ... 18'65 2. ., less residuals .... 5s. 9'14d. ... 7*28 3. Purification .......... — ... 3*3S 4. Salaries .............. — ... 0*57 5. Wages.................. — ... 3*18 6. Maintenance............ — ... 2*81 7. Gross cost in holders.. — ... 25’50 8. Net „ „ ... — ... 14*13 With the foregoing figures as a guide, and assuming the quantity of gas required to be 30,900,000 cu. ft. per annum, a comparison of two qualities of coal gives the following results:— (A) Coal at 12s> and yielding 9,500 cu. ft. per ton. (B) „ 14s. ., 11,000 „ 1. Cost of carbonising, repairs and maintenance = 6s. per 1on. 2. Coke = 9 cwt. per ton of coal carbonised and valued at 10s. per ton. 3. Tar and liquor = 50 gals, of coal carbonised, and valued at 5s. 6d. per 100 gals. £ s. d. <£ s. d. (A) 30,000,000 = 3 158t 112s p t = j 891 16 0 9,500 1. Urbanising,&c.,3,158t.at6s.p.t. = 947 8 0 ---------- 2,842 4 0 Deduct value of residua's— 2. Coke1,4211.at 10s.p.t.= 710 11 0 3. Tar, Ac., 3,158 x 50 = 157,900 gals. at 5s. 6d. per 100 gals. = 434 4 6 ------- 1,144 15 6 Net cost of coal..................... 1,697 8 6 (B) 30,000,000 = 2 727 t. at 14s. p.t. = 1,908 18 0 11,000 1. CTb’nising, Ac., 2,7271. at6s. p.t. = 818 2 0 ---------- 2,727 0 0 Deduct value of residuals— 2. Coke 2’727 x 9=1,2271. at 10s. p.t. = 613 11 6 20 3. Tar, Ac., 2,727 x 50 = 157,900 gals. at 5s. 6d. per 100 gals........ = 374 19 3 ---------- 988 10 9 Net cost of coal 1,738 9 3 This shows a saving of <£41 0s. 9d. in favour of (A), notwith- standing the necessity of having to purchase 431 tons more than is necessary with (B). Although there was much to be said in favour of high makes, it was often a question of circumstance, such as the local market for residuals. In his opinion, however, it was unprofitable to increase the make at the expense of the residuals. Amonst the many things to be learnt was that where the sale of residuals was sufficient to pay the coal bill the price of gas was low. An Unconformity in the Coal Measures of Somersetshire. In the Geological Magazine for July, Mr. Frank Dixey discusses the relation of the coal measures to the lower carboniferous rocks in the Clapton-Clevedon district, Somersetshire. In this region there are two separate outliers of coal measures lying on the northern flank of a ridge of carboniferous limestone extending from Clevedon eastwards beyond Clapton in Gordano. There have been various interpretations of the structure in this area, which was ascribed by Prof. Lloyd Morgan to a fault, and by Dr. A. Vaughan to an unconformity. Mr. Dixey has now mapped the area on the 6 in. scale, and demonstrates the existence of an unconformity in three ways, viz.—(1) By the overstep of the coal measures from the carboniferous limestone across the lower lime- stone shale on to the Old Red sandstone; (2) by the occurrence of small ‘‘islands” of carboniferous lime- stone, which rise, six in number, through a covering of coal measures; (3) by angular discordance between the coal measures dipping northward and the older rocks dipping in a southerly direction, as is proved by small exposures near Clapton church. In the Clevedon area the relation of the coal measures to the underlying rocks is masked by faulting. These observations strengthen the view of Dr. A. Vaughan that there was in this area a post-Toumaisian upheaval and denudation, before the coal measures were deposited. Unconformity between the coal measures and the lower carboniferous has also been detected by Mr. E. E. L Dixon in the Titterstone Clee Hills, and in the Forest of Dean by Prof. T. Franklin Sibly. It may also be mentioned that a local unconformity in the coal measures them- selves has been noted in the Border coalfields, thus showing that earth movements, and contemporaneous denudation occurred locally throughout the carboniferous period. THE GERMAN AND AUSTRIAN COAL AND IRON TRADES. We give below further extracts from German periodicals that have reached us, showing the course of the coal and iron trades in Germany and Austria :— Control of the Iron Industry. It appears that the plans of the German Government are not at all necessardy confined to the coal industry. The Cologne Gazette warns iron industry associations— above all, the Crude Iron Syndicate, and also the Steel Works Association—that the action of the State in regard to the coal industry may very well be the beginning of a development which will involve the iron industry also. The Cologne Gazette continues: “In the iron industry, it is true, the conditions are less simple than the conditions in the coal industry, and the diffi- culties in the way of organisation under control of the State are greater. The menace to the iron industry may, therefoie, be smaller. But it exists, and the situation produced by the war, as a result of which the needs and demands of the State are forced to the front, has very considerably increased the menace. This fact ought to be taken into very serious consideration hence- forward in the whole business policy of the iron industry associations.” Saxon Collieries and their Contracts. According to the Cologne Gazette, the Saxon collieries regard Italy’s declaration of war as applying also to Germany and therefore justifying them in at once cancelling all German contracts, so that they can sell at considerably advanced rates. This procedwe has aroused great resentment in industrial circles, and the Chemnitz Chamber of Commerce, having made unavailing efforts to bring about an agreement, is pressing the Government to intervene and protect Saxon industries. Kohlenkontor’s Report. The annual report of the Rhenische Kohlenhandels und Reederei - Gesellschaft m.b.H., Kohlenkontor. Millheim (Ruhr), states that in the first three months of the past financial year the deliveries from the Syndicate were 200,000 tons less than in the previous year, and, though better supplies were beginning to come forward just before the outbreak of war, the conditions again changed for the worse. The total quantity of coal handled in the year amounted to 19,553,225 tons (12,644,345 tons), a deficit of about 2,090,000 tons, 900,000 tons of which represent the falling off in supplies to Holland. In August and September alone the deficit amounted to 1,140,000 tons. So much coal was withdrawn from the stockyards at Ruhrort and the Upper Rhine harbours—in order to prevent a famine— that at the end of March the stocks were lower than they had been for years. The opening of the Rhine- Herne Canal assisted in counteracting the traffic delays caused by the mobilisation ; and the traffic from the pits on the canal to the Rhine increased from 16,253 tons in August to 166,158 tons'in March. Under the Export Prohibition Order, permis ;ion was obtained for the shipment of about 60 per cent, of the quantity sent out in the corresponding period of the previous year; but in May and June the shipments were restricted to 40 per cent., a limitation which seriously affected the trade with Holland and Switzerland. Sales of coke, which is not affected by the prohibition, have been very considerable, especially during the cun-ent