March 28, 1913. 'THE COLLIERY GUARDIAN. 655 ston. One of the questions raised was as to whether a “ wheel brae ” worked by gravity could be considered as a mechanical haulage.” In this respect the Sheriff found against the Home ’Office, who prosecuted. He also found that Mr. C. A. Carlow, certificated manager, did not take upon himself the duty as agent to compel the use of backstays. On the first point the Sheriff consented to state a case. At a meeting of the Scottish Coal Trade Conciliation Board on Tuesday, it was agreed to defer dealing with the employers’ claim for a reduction of miners’ wages to the extent of 12-i per cent, on the 1888 basis, and to endeavour to arrive at a new wages agreement. The Conciliation Board for the Federated Districts of England and North Wales met in London on Wednesday to consider an application from the miners for an advance of wages by 5 per cent, on the 1888 basis. The meeting was adjourned to April 15. A meeting of the North Staffs Institute will be held on Monday. In making his statement on the Navy Estimates in the House of Commons on Wednesday, the First Lord of the Admiralty outlined the policy of the Admiralty in regard to the use of oil fuel, and stated that more than £1,000,000 was included in the present estimates for the purchase, transport and storage of oil reserves. At the same time, he pointed out the impediments, due to price movements and the scarcity of supplies in the Empire, The Miners’ Federation of Great Britain met at the Westminster Palace Hotel yesterday to con- sider various recommendations of the executive committes. The conference unanimously endorsed the view of the executive that on the figures of the recent ballot no action could be taken for the adoption of a general five days week policy. A recommendation of the executive was also .unanimously accepted to the effect that no ^general strike should be declared or continued /unless two-thirds of those voting vote in favour of such a strike or its continuance. The conference adjourned until to-day, when the xihree-shift system will be discussed. On the same day a deputation waited upon the Prime Minister in regard to evictions from colliery houses during strikes, but did not succeed in .obtaining any very sympathetic assurance. In their prosecution of the Ignition Summerlee Iron Company the or Government has met with Explosion, another reverse in their attempted interpretation of the »Coal Mines Act, 1911. Plain commonsense has again triumphed, which might be presupposed in a case tried before a Scottish court of justice. While perusing the evidence, the reader can hardly help hearing, as an accompanying refrain, the almost classical reported utterance of one of H.M. inspectors of mines at the Bentley prosecution: “ It is not a question of danger; it is a question of the law.” The prosecution was instituted by the Home Office under the Coal Mines Act, 1911, sec. 32 (1) (6), which says that no lamp or light other than a locked safety lamp shall be allowed or used in a seam (except in the main intake airway within 200 yards from the shaft) in which an explosion of inflammable gas causing any personal injury whatever has occurred within the previous 12 months. The case for the prosecution was that on two occasions an explosion of inflammable gas had occurred at Prestongrange Colliery, in each case a man being injured, and that the owners of the colliery .continued to allow lamps or lights other than locked safety lamps to be used. On the first occasion, which was the more important, a pit repairer, named John Pryde, who had a naked light in his cap, set fire to a small quantity of gas near the roof. He noticed that the flame just rolled across the roof, turned and went back again, and then went out, the phenomenon occupying an appreciable length of time. There was no noise or violence and his lamp was not blown out. He was slightly burned on the arm, but not sufficiently to prevent him going on with his work, and he remained to the end of the shift. The prosecution contended that this phenomenon constituted an explosion within the meaning of the Act, while the defence declared that it was not an explosion, but merely an ignition. According to the opinion of Mr. R. G. M. Prichard, H.M. senior inspector of mines for the Scotland district, it is impossible to have an ignition without an explosion, and if at any time any quantity of gas, however small, is lit under any circumstances in a coalmine, an explosion has occurred in that mine, even if it caused no sound and there was no evidence of violence. In describing a case where nobody had been injured, he might use the word “ ignition,” but the occurrence would nevertheless be, at the same time, an “ explosion.” There appears to be no legal definition of the terms 11 ignition ” and “ explosion,” but it is evident that they are not considered to be synonymous for the following reason. According to Notice of Accidents Act, 1906, section 2 :— Where, in or about any mine to which this Act applies whether above or below ground, any accident occurs which . . . is caused by any explosion of gas or coaldust . . . and causes any personal injury whatever to any person employed in or about the mine . . . the owner, agent, or manager of the mine shall forthwith send notice . . . Section 5 of the same Act gave power to the Secretary of State to extend the provisions as to notice of accidents to dangerous occurrences, and an Order, dated December 22, 1906, was made extending the provisions so as to include, inter alia, the following class of occurrences, whether personal injury or disablement is caused or not. “ All cases of ignition of gas or dust below ground other than ignitions of gas in a safety lamp.’’ From the above it is apparent that, technically, an explosion is an accident, while an ignition is a dangerous occurrence. The Notice of Accidents Act, 1906, was repealed, in so far as it applied to mines, by the Coal Mines Act, 1911, and the matter was embodied in the new Act: the Order remains in force by virtue of section 126 (a). Prof. Latham’s evidence, though at first sight appearing to confirm the position taken up by the prosecution, actually defeats it. In his opinion an explosion implies a previous ignition, and whenever there is a propagation of a flame throughout an inflammable mixture of gas, there is always an explosion. If therefore there is no propagation, the phenomenon remains an ignition without becoming an explosion. The question is, what constitutes propagation ? In a paper read before the Chemical Society by Dr. Wheeler and Mr. Burgess* which contains the results of investigations made at Altofts for the Committee on British Coaldust Experiments appointed by the Mining Association of Great Britain, it is stated that self-propagation cannot take place unless the mixture lies between the a lower limit ” and the “ higher limit,” and such a * Transactions of the Chemical Society, 1911, vol. 99. mixture is distinguished by the fact that ignition promotes the inflammation of all the gas, and a second ignition shows no sign of combustion. In the case of Pryde, the flame rolled across the roof, turned, and went back again, and therefore passed through the mixture twice. The mixture could not have been uniform between the higher and lower limits necessary for general self-propagation, and accordingly there was no explosion. Prof. Burns undoubtedly gave the popular view of the question when he stated that the criteria of an explosion are violence and noise— producing some mechanical result. A kindling or catching fire does not necessarily result in an explosion. An explosion is instantaneous. It would seem that a very thin layer of an inflammable mixture existed a little below the roof—sufficient to cause an inflammation, but not an explosion. There is a great want of definiteness in much of the scientific terminology applied to mining, and this evil shows itself when such terms are employed in legislation without definition. An instance of confusion was recently pointed out in connection with the examinations for firemen’s certificates and the use of the terms “ inflammable gas,” “ firedamp,” and “ gas.” Trade Summary. The London coal trade for the past week has been somewhat slow. The holiday traffic on the railways and the general exodus from town has left many orders unexecuted. Wednesday was the only market day for the week on the London Coal Exchange. The cold weather has, however, kept the demand firm. Prices are unchanged, but stocks are low. Manufacturing coals are selling freely, especially small nuts and slacks, and all qualities of house coals are steady. Shippers are anxious to buy forward, and the Baltic trade is opening earlier and stronger than usual. Little business is being transacted on the Tyne, but prices are firmly maintained. The Durham coal trade is quietly steady, and prospects are bright. Holiday influences predominate in Lancashire. There is a consistent call for slack. Although active business has been small in West York- shire, a heavy movement of traffic has taken place. Business prospects are excellent in South Yorkshire. The Derbyshire coal trade is steady and promising. Prices are fully maintained at Cardiff, although there is rather less pressure for small coals. The Scottish shipping trade is rather slow, but the home demand continues heavy. THE IRISH COAL TRADE. Thursday, March 27. Dublin. The holidays being over, business is once more fairly active in most classes of fuel, and sales of house qualities are well up to the average for the season, owing to the continuance of cold weather. There has been an advance of Is. per ton in kitchen coal in consequence of the scarcity occasioned by the strike at Garston, but other sorts remain unchanged. Quotations in the city are as follow:—Best Orrell, 27s. per ton; best Arley, 26s.; best Whitehaven, 25s.; best Wigan, 25s.; best kitchen, 24s.; best Orrell slack, 21s.; house coal, retail, from Is. 7d. to Is. 8d. per sack; coke, 23s. per ton; steam coals from about 22s. per ton upwards. Prices of Irish coals at Arigna, County Leitrim, are advanced Is. 8d. per ton on all classes owing to the Insurance Act, increased cost of stores, and increased wages and taxation. Quotations at the pit mouth are:—Best coal, 15s. lOd. per ton; nuts, Ils. 8d.; and culm, 9s. 2d. The coaling vessels arriving in the port amounted to 35, being chiefly from Whitehaven, Liverpool, Irvine, Ayr, Manchester, Maryport, Glasgow, Preston, Runcorn, Partington, Cardiff, Newport, Troon, Saundersfort, West Bank, Newcastle-on-Tyne, Workington, Girvan, Ardrossan and Widnes. The total quantity of coal discharged upon the quays was 13,600 tons. Belfast. Business is opening up fairly well, and there is no further change in prices since the advances which were made a week or two ago. The supply of English house coal is restricted owing to the position at Garston docks and the delay in getting cargoes at other ports. City prices are as follow :—Giant’s Hall Arley coal, 27s. 6d. per ton; Hartley, 26s. 6d.; Wigan, 25s. 6d.; Orrell nuts, 26s. 6d.; Scotch house, 23s. 6d.; Orrell slack, 23s. 6d. Quotationsex-quay:— Arley house coal, 24s. per ton ; Scotch household, 20s. 6d.; Scotch steam coal, 17s. to 18s. per ton; navigation steam, 17s. to 18s.; Welsh steam. 20s.; English steam slack, 17s. per ton delivered. Coaling vessels arriving during the week were chiefly from Lydney, Irvine, Point of Aire, Liverpool, Ellesmere Port, Workington, Whitehaven, Partington, Manchester, Sharpness, Maryport, Preston, Britonferry, Ardrossan, Ayr, Glasgow, Birkenhead, Cardiff, Newport and Campbeltown. The total number of colliers entering the harbour from the 2nd to the 15th inst. amounted to 110.