MINE EXPLOSIONS

Evening Post, Volume LXXXVIII, Issue 69, 18 September 1914, Page 2

MINE EXPLOSIONS

THE DEADLY €OAL DUST HOW TO NEUTRALISE IT. ENGLISH SCIENTIST'S LECTURE. An unusually interesting and instructive address upon " The Nature of Explosions," with special reference to explosions in coal mines, was , delivered by Professor H. B. Dixon, one of the visiting British scientists, in the Concert Chamber at the Town Hall last evening. Professor Dixon, who is one of the leading authorities on explosives, is Professor of Chemistry at Manchester University, and a past-president' of the Chemical Society. He illustrated his remarks by a series of demonstrations with special apparatus fitted up on the stage, and with a number of limelight views. The Hon. W. Fraser, Minister of Mines, .presided over a large audience, which followed the lecture and the experiments with the closest attention. The Chairman, in introducing the lecturer, expressed the deep appreciation | of the Government at Professor Dixon's action in placing his valuable services at the disposal of the Uovernmeut in investigating the cause of the lamentable disaster at Huntly. Professor Dixon said he was glad to be able to place his services at the disposal of the Government, and he wished to express his deep sympathy with the victims of the catastrophe. He had investigated most of the great mining disasters that had taken place in England during recent years, and he would be gratified to do what he could to elucidate the sad accident at Huntly. It would be a great pleasure to him if he could do something which would help to minimise such disasters in future. Proceeding^ with his lecture, Professor Dixon explained that explosions were the result of one of the simplest chemical reactions. They all admired the work of German chemists, but their fault was that they were not as thorough as they might be, and were inclined to look down upon work done outside Germany. Explosions had three distinct periods — first the flame, then the vibration, and then the detonation. He demonstrated this by means of explosions in glass tubes and photographs showing the firing sparky the swings in vibration, and the explosion wave. He also experimented with gun-cotton, cordite, lyddite, and other explosives, startling the audience occasionally with loud though harmless reports. Referring 10 explosions in mines, he stated that coal dust in many ways resembled fire-damp in explosibility, and in some cases was easier to fire. It was therefore essential to study the firing itself, because he believed all the big, explosions were due' to coal dust, it being impossible to maintain that all the intake airways were filled with firedamp. With an initiatory explosion, however caused, the coal dust in a mine was stirred up into a cloud, and with the flame running through it produced a greater explosion. That being so, it was necessary that they should take some precaution against the possibility of raising coal dust. They must eitlier damp oi mix something with it. If they mixed some inert dust with it he held that they would neutralise its explosive capacity. He had been experimenting for beveral years in Cumberland in this connection, and, as a result of hit. investigations, had come to' that conclusion. Some prejudice existed to adding ajiother dust, but the answer to that was that tho coal dust in a mine should be cleared up from time to time, and other dust, which it was not dangerous to bring, put down so as to mix with what was left, and would , accumulate. In some of the mines at Home now powdered shell was being used. As an illustration of the force of ; his contention he threw some ordinary coal dust through a naked ilame, and later some more mixed with inert dust, disclosing a marked difference. The ordinary coal dust went off with a flare, while the mixture disclosed only a dull glow with very much less evidence of explosiveness. The lecturer concluded by screening a number of views of the experimental station erected by the Imperial Government in Cumberland. He added that if the 1 of their experiments would stop the spread of accidental explosions lin mines, or would tend to minimise them, then it would not be work thrown away. Personally; ho would rather pec- | puade mine managers to do the right thing than to compel them. (Applause.) A hearty vote of thanks was accorded to the Professor for his address, and also to Mr. Edwards, his assistant, for his services in connection with the experiments.