August 21, 1911. THE COLLIERY GUARDIAN. 433 ____________________________________________________________________________________________________________ less than 6 or 7 per cent. This had been confirmed by Prof. Thornton, of Armstrong College. The explosion could not have possibly taken place in the pump room. He examined the motor, but found no sign of explosion, also the switch, and was satisfied it could not have caused the explosion. And there must have been gas there for an explosion to be possible. The motor, the switcher and the starter were thoroughly reliable. The position of the door, after the explosion, was, in his view, the result of a rebound of gas, the force of such rebound being about half the original force. His idea was that part of the gas rushed into the pump house and the rest passed on. The whole idea of the explosion occurring in the pump house was far fetched and it was impossible to substantiate it in any way. There was no heating or burning or anything to show that the explosion had been caused in the pump room. By the Inspector : Witness did not think there might be sufficient heat to cause an explosion, and yet not to leave other signs of heating. Asked if the electrical machinery was in accordance with the regulations, witness said there was only one part—the way in which the cables were carried—which could have been improved. Mr. R. Nelson, H.M. electrical inspector, said appearances in the pump house were quite consistent with the electrical apparatus having ignited a body of gas. They might get an ignition from an electric switch or motor, and see no effect afterwards on the motor or switch. He had had recent experience of an explosion occurring in a switch-box at a colliery in Durham. He had known several cases of that. The most likely cause in this case was sparks from the starter. The plug which confined the oil was loose, sufficiently to allow of a leakage of oil. Mr. Granville Poole, H.M. inspector of mines, spoke to finding of gas in the pump house and an explosive mixture in the dip workings. Where the air came in at the door- way was lower than the top of the pump house. It was, therefore, possible to have an explosive mixture at the top of the pump house which ignited, and that the explosion developed its greatest force when it encountered fresh air where the men were working. He agreed with a previous witness that they got practically little force at the point of origin of an explosion. The Coroner, in summing up, said there was a doubt as to how the explosion originated. It was difficult for the jury to judge, but he did not think it much mattered as far as they were concerned. If there had been a violation of the Coal Mines Act in regard to inspection, it did not concern them unless they were of opinion that it led to the explosion. He advised them not to attempt to deter- mine when, how and where the explosion originated. The jury retired to consider their verdict, and, on their return the foreman said they had found a unanimous verdict that Wilkinson met his death through being knocked down by an explosion-of gas, being suffocated by water and receiving an injury to his brain; that Smith and Wright were both suddenly killed by an explosion of gas, but it was impossible to say in what locality or how the explosion arose. The jury recommended that the law should be adhered to, and that the whole of the places should be examined in the future before anyone went to work in any district. Also that the door of the electric engine house should be put on the. other side, so as to bring the engine house within the intake and not in the return. ______________________________________ INDIAN AND COLONIAL NOTES. ______________________________________________________________ India. Coal Industry in 1913.—The Report on the Working of the Indian State Railways Coal Department during 1913 gives the following particulars of the coal consumption in British India during that year, the figures for 1912 being added for purposes of comparison :— 1912. 1913. Tons. Tons. Coal mined in India ............ 14,706,s39 ... 15,486,318 Coal imports .................... 560,791 ... 644,934 Gross total.......... 15,267,130 Coal consumed on Indian railways 4,709,200 Indian coal exported by sea...... 2,942,772 ... 16,131,252 ... Not stated. ... 3,155,261 _____________________________ Africa. New Customs Tariff.—The text of the new Customs and Regulations of the Union of South Africa has just been published as a supplement to the Board of Trade Journal. The duty upon coal and patent fuel remains 3s. per short ton, whilst that on coke is still Is. per ton. Blasting com- pounds, as before, are taxed at the rate of 2Jd. per lb., a rebate of Jd. per lb. being allowed on explosives of British manufacture. The duty on motor spirit has been increased from Id. to 2d. per imperial gallon. A 25 per cent. ad valorem duty is levied on bricks (with a rebate of 3 per cent.), and a 3 per cent, ad valorem duty on ambulance materials, ammonium nitrate, brattice cloth, bolts, nuts, screws, nails, rivets and washers, liquid cement, chains for hauling, cranes, elevators and shears, crucibles, cupolas, etc., fireclay, fire extinguishing appliances, transmission hose, jacks, mining and other machinery, rough and rolled iron, sheets, angle, bar, channel, hoop, rod, plate, H.T. and similar iron or steel, tin-plates, rails, buckets, skips and tubs, engine packing and lagging, pipes and tubes, tram- way and railway material, rope for driving, drilling and water boring, mining tanks and vats, water boring and pumping apparatus, wire, wire netting, wire rope, and wood. A rebate of the whole of the duties upon this class is granted on goods produced in the United Kingdom and reciprocating British Colonies. __________________________ Australia. Queensland Coal Mines in 1913.—According to the annual report of the State Mining Engineer, 1,037,944 tons of coal were raised in Queensland in 1913, comprising 330,981 tons of screened coal, 606,006 tons of unscreened coal, and 100,957 tons of small coal. In 1912, 902,151 tons were raised. The following is a comparison of the quantity and value of the coal raised in each of the coal mining districts of the State, with the figures for 1912 :— 1912. ( > Average value District. Tons per ton raised. at pit’s mouth. s. d. Ipswich ... 598,505 ... 6 7 . Darling Downs ... ... 90,965 ... 8 6'5. Wide Bay & Mary- borough ....... 119,732 ... 10 10‘5... Rock hampton (Cen- tral) .......... 13,447 ... 10 6 ... .......... Clermont........ 79,501 ... 7 6 ...... Other ............... 15 ... — ... 1913. (-* Average value Tons per ton raised, at pit s mouth. s. d. 695,422 ... 7 0*7 103,538 ... 8 5'9 129,611 ...10 11'39 13,*74 ...10 4'3 93,799 ... 7 7 _________ _______ Total........ 902,166 ... 7 6 ... 1,037,944 ... 7 9'3 Returns obtained show that 230,344 tons of Ipswich coal was shipped as bunker or cargo coal, and the remainder used-for general purposes, such as for gas and meat works, railways, etc. About 100,000 tons of coal and approxi- mately from 50,000 to 60,000 tons of coke is obtained from New South Wales every year. The only shipment from oversea was 1,986 tons of coke landed at Rockhampton from Germany. A small shipment of 50 tons of Queensland coal was sent to Timor. The quantity of coke made in Queens- land was 14,942 tons. Following the discovery of the extension of the Aberdare seam at Denmark Hill, the Ipswich City Colliery has now commenced opera- tions, the original prospecting work having been followed by the driving of a tunnel. The seam is highly inclined, but of good quality. The surface equipment of the mine, including railway siding, will be completed shortly.. The machinery and equipment at a number of the collieries in the Ipswich district has been added to and improved during the year, and a good deal of attention given to prospecting work, several new shafts having been sunk in connection with the older collieries at Bundamba. On the Darling Downs several new collieries have commenced operations during the last few years, and two were opened last year. These are on the Cooyar Railway, about 12 miles from the collieries at Oakey and Gowrie. The Bur- rum collieries show a larger output in 1913 than in 1912, and at Howard, as well as at several other localities in the Maryborough district, more particularly Urangan and Burrum, bores for coal were put down during the year. The development of the Blair Athol field is an important factor in the coal mining industry of the central portion of the State, and the annual output of that district has increased from a little more than 5,000 tons to over 95,000 tons in the last four years. Further boring of the extensive coal areas of the Central district has been carried out during the year, with a view to locating at convenient points coal suitable for general purposes and for coking, and the most impor- tant operations of this kind were carried out by the Mount Morgan Company at the Mammoth coal areas. The boring carried out by the company was commenced at Frenchman’s Plains, and extended to the railway, with results which it is anticipated will lead to the opening up of another colliery in that district. The further testing of the Bowen coal deposits and the assistance granted from the vote in aid of mining has had a good result in further disclosing the coal possibilities of the Northern portion of the State. The coal so far tested is reported to be of good steaming and coking quality. The site of the company’s operations is a little over 40 miles from Bowen, and the actual length of. rail- way construction required to connect with the port is 43 miles. The Mount Mulligan Mine, which will become the first active colliery in the North on the completion of the railway from Dimbulah, on the Caims-Chillagoe line, is being steadily developed, and preparations made for the erection of a coke making plant. As shown by returns, the total number employed in coal mining operations was 2,332. In coal mines there was one fatal accident in 1913, but no fatalities in the previous year. Increased output and improving conditions are specially noticeable in the year s record of the coal mining industry, but very little change is to be noted in the general conditions of mining in other districts, except, perhaps, in the direction of curtailing operations somewhat at the older gold mining centres. A powerful steam plant for generating electricity and an exten- sive coke making plant are in course of erection at the Mount Mulligan Coal Mine, in the Chillagoe district. The number of winding ropes tested on the testing machines during the year was 435, being 61 less than in the previous year. Twenty-three ropes were condemned. Early in the year a fire, due to spontaneous combustion, occurred below the 80 ft. level in the Hampden South Consols Mine. Some further trouble from the same cause was experienced later in the year in the south end of the mine in a low-grade pyritic stope. A fire occurred in the Blair Athol Mine, in the Clermont district, where, owing to its early discovery and the prompt measures adopted, stoppings were built and it was. soon under control. Most of the fires in col- lieries in the Ipswich district have been kept sealed off, but at Fairbank Colliery an old fire broke out and made such rapid progress that it could not be dealt with under- ground, aud it became necessary to shut down the mine permanently. New special rules under section 51 of the Mines Regulation Act were adopted at all the collieries during the year. These rules for the conduct and guidance of officials and all persons in the collieries replace the old set of rules approved under the Mining Act of .1898, which, under the provisions of the new Act, remained in force until so replaced. Permitted explosives are now more largely used in the collieries, and a considerable supply of one of the brands of this class of explosive was, during the year, found to be seriously defective on account of failure to detonate properly, and extraordinary flaming qualities. An investigation showed that the defective material was con- fined to two particular batches of the explosive, and on the agents agreeing to withdraw all defective material, the explosive was again allowed into the collieries with certain restrictions. Canada. Our Toronto correspondent says :—An expedition to pros- pect for coal deposits along the shores of Hudson Bay will shortly leave St. John, Newfoundland, by the schooner “ Laddie.” It is being financed by Mackenzie and Mann, of the Canadian Northern Railway, who are desirous of securing coal supplies in that area to utilise in connection with the Hudson Bay Railway now being built from Le Pas, Man., to Port Nelson. The Canadian Northern has a junction with the Hudson Bay at Le Pas, and will probably operate the latter road when it is opened. Pro- vision will be made at Port Nelson for the storage of coal in large quantities, but the cost of freight from the present distant sources of supply will be very heavy, and the find- ing of coal deposits at any point comparatively accessible for ships plying on Hudson Bay would be of great advantage. Hillcrest Explosion.— The jury investigating the Hill- crest disaster declared that death was occasioned by an explosion caused by gas and dust. A rider was added by the jury, in which they declared that they believed the company had infringed the Mines Act. They further sug- gested that the Government enforce a monthly inspection of all men working in mines to see that no matches are carried into the mine, and that a sufficient supply of life- saving apparatus is kept as near the mouth of the mine as possible. ___________________________ COAL STORED UNDER WATER * By M. Rolland D’Estape. When coal stored under water comes to be used, how will its behaviour compare with that of fresh dry coal? The author has been experimenting on this matter. Coal was stored for some months under water and then put into use, and its behaviour put under observation. The silo used had a capacity of 3,200 tons of coal; it is circular, and is of reinforced cement, above the ground level, with pipes for withdrawing water, and a door at the ground level for withdrawing coal. The sunk silo presents the advantages that it looks better and is more conveniently filled, and that it can be used for piling additional coal upon, so that ground area is economised; but it needs pumping to withdraw the water, and the withdrawal of coal is difficult, whereas it ought to be as easy as possible on occasions of emer- gency. With a silo above the ground level, any leakage can be more readily detected; and in any event a silo ought to remain watertight through its own strength, without taking into account any lateral support it may derive from the surrounding soil. In the particular case the soil was rather shifting, and a sunk silo would have proved materially more expensive. The silo was filled to two-thirds of its height with through coal, and the remaining third of the height was filled up, in three areas, with through coal containing about 40 per cent.' of small coal, with screened coal, and with large nuts, respectively. Tests showed that coal absorbs very little water; not more, even with small coal, than 0-7 per cent, in 20 days. The quantity of water adherent superficially varies very much with the size of the coal; with small coal, 15 to 20 per cent.; 2 to 3 per cent, for peas and beans; and 1-5 per cent, for nuts. Simple draining-off is a very ineffective means of drying wet coal. The water was drawn off; this took 10J hours, but water continued to drain off the coal at the rate of about 3-6 galls, per minute. This draining-off con- tinued for a long time, and, even at the end of a fort- night, it amounted to 0-11 gall, per minute. Eighty hours after the drawing off of water was begun, 20 tons of the through coal was taken off the top. This con- tained 9-8 per cent, of water. It was put into the conveyors exactly as if it had been fresh coal from the boats. When it reached the retort house it contained 6-2 per cent, of water. There was no special difficulty in handling it; it was somewhat unwilling to move, and had to be helped on with the tool. In some six hours more it found its way into the retorts; and it worked perfectly with the charging machines, both De Brouwer and Sautter; and the retorts filled evenly. Such being the experience with the through coal, it was evident'that there would be no difficulty with the screened coal or the large nuts. Experience confirmed this; the screened coal was slightly indolent, and that was all. The screened coal started with 6-8 per cent, of water, and arrived with 5-0 per cent.; the large nuts started with 3-6, and arrived with 2-8. In the charging wagons, after six hours, the through coal was found practically to remain at 6-2 per cent, of water; the screened coal stood at 4-6; and the large nuts at 2*0 The large nuts, therefore, dried off .most rapidly. Through coal from the bottom of the silo was now withdrawn, 7| days after the tapping off of the water had been begun. 420 tons of it was withdrawn and sent to the retorts, being treated exactly as if it were fresh through coal. It started with 8-8 per cent, of water, and reached the retort house with 5 per cent. After 10| days the water in the coal was 6-2 per cent.; 120 tons of it was sent up directly by the lifts, and arrived with 5-2 per cent, of water. The 600 tons treated during the tests produced no appreciable cooling of the benches. But if the use of the wet coal had been continued there would assuredly supervene a cooling, so that either the producers must work more actively or else the charges be reduced, for the 6 per cent, of water w’ould have to be evaporated. The number of heat units used would have to be raised by about 4J per cent. It is, therefore, possible, without any special difficulty to use through coal stored under water some three or four days after the withdrawal of the water has begun; and after passing along the conveyors, the coal arrives dry enough to be distilled without inconvenience, and without taking any other precaution than that of slightly pushing the producers or reducing the charges. In time, after coal has remained in the silos for two or three years, it is intended to test the gas obtained from the stored coal. In the meantime, the results from the coal referred to above were absolutely com- parable to those from fresh coal; but the time of storage had been too short (some months) to test the effects of prolonged storage. * The Gas World publishes this summary of a paper read before the Society Technique de I’lndustrie du Gaz en France at their annual meeting.