476 Sir Henry Cimynghame [Feb. 19, 



This new theory, that coal-dust played a part in mine explosions, 

 did not receive much attention in England, but in France, Mr. Souich 

 and others attributed explosions in part to dust, until in 1-^75 

 Mr. Vital made a series of experiments on a small laboratory scale, 

 from which he concluded that dust might of itself alone give rise to 

 disasters. 



In 1872 the first Coal-mines Regulation Act was passed in Great 

 Britain, and Mr. Galloway, one of the newly appointed inspectors, at 

 once turned his attention to coal-dust. In 1876 he presented a paper 

 to the Royal Society in w^hich, while admitting that explosions were 

 usually originated by gas, he argued that they could be continued by 

 coal-dust alone, and that if the dust were only fine enough, an explo- 

 sion begun in a confined space might be propagated through a mine. 

 Several commissions in Great Britain and in Germany then experi- 

 mented upon the subject. 



Still, however, the mining world was not convinced, and even in 

 1885 a Royal Commission reported adversely to coal-dust as the 

 principal cause of explosions in mines. 



In 1886, Messrs. W. N. Atkinson and J. B. Atkinson, inspectors 

 of mines, produced an excellent treatise on the dangers of coal-dust. 

 Their work Avas written from practical observation of various 

 explosions. 



In this work appeared an analysis, made by Professor Bedson, of 

 gases found in the Usworth mine after an explosion, which revealed 

 the presence of no less than 2 J per cent, of carbonic oxide, which, for 

 reasons I will presently give you, was alone almost conclusive proof 

 that coal-dust had played a part in the explosion. 



In 1887 a Royal Commission on coal-dust was appointed, which 

 employed Mr. Henry Hall — one of the present inspectors of mines and 

 one of the earliest to adopt the coal-dust theory — to conduct some 

 experiments. Mr. Hall put a cannon of 2-in. bore, charged with 

 Ij lb. of gunpowder, pointing muzzle upwards, at the bottom of a 

 shaft 50 feet deep. A sack of inflammable dust was then tossed down 

 the shaft, so as to fill the air in it with a cloud of dust, and the cannon 

 fired. Repeated explosions were the result with great tongues of 

 flame, though no gas whatever was present. One of these explosions 

 is shown on the screen. 



[Photograph.] 



From this date the dangers of coal-dust began to be fully recog- 

 nised, and now it may be considered fully proved, that though gas 

 may cause small explosions in parts of the mine, general explosions 

 are due to coal-dust ignited either by a small local gas explosion, or 

 else by a blown-out shot. 



The arguments for this view are as follows. 



1. The travel of the explosions in roads over long distances, which 



