1884.] Influence of Coal-Dust in Colliery Explosions. 43 



colliery explosions. I think I may safely claim, however, that no 

 earlier author had gone the length of crediting it with the role of 

 principal agent, and relegating fire-damp to a secondary position. 



It is also admitted, I believe, by everyone familiar with the subject, 

 that my experiments with mixtures of coal-dust and air containing a 

 small proportion of fire-damp were original. Similar experiments 

 were subsequently made by members of the North of England 

 Institute of Mining and Mechanical 'Engineers,* by a committee of 

 the Chesterfield Institute of Engineers.f by Professor Abel on behalf 

 of the Home Office and the Royal Commission on Accidents in 

 Mines, J and by others in this country, by MM. Mallard and Le 

 Chatelier for the Commission du Grisou in France, || and by others on 

 the Continent, all of which led to the same conclusion, namely, that 

 air containing too small a proportion of fire-damp to render it inflam- 

 mable at ordinary pressure and temperature becomes so when coal- 

 dust is added to it. Differences of opinion were expressed as to the 

 actual proportion of fire-damp, the comparative fineness of the coal- 

 dust, and the quality of the coal necessary to the attainment of this 

 result, but the general conclusion, in every case, was the one I have 

 stated above. 



In my first paper, already referred to, I had said : " If it could be 

 shown, therefore, that a mixture of air and coal-dust is inflammable 

 at ordinary pressure and temperature, there could be no difficulty in 

 accounting for the extent and violence of many explosions which 

 have occurred in mines in which no large accumulations of fire-damp 

 were known to exist," and, immediately following these words, I 

 gave what appears to me to be a new hypothesis regarding the mode 

 of occurrence of great colliery explosions. 



My reasons for thinking it necessary to show that a mixture of 

 air and coal-dust alone is inflammable were, first, that after some 



" Trans. N. of E. Inst. of Mining and Mechanical Engineers," vol. xxviii, p. 85. 



t " Trans. Chesterfield and Derbyshire Inst. Mining, &c., Engineers," vol. x, Parts 

 I and II. 



J () Report on the Kesults of Experiments made with samples of Dust 

 collected at Seaham Colliery in compliance with the request of the Secretary of 

 State for the Home Department, conveyed by a letter, dated November 4th, 1880. 

 By F. A. Abel, C.B., F.E.S., President of the Institute of Chemistry, Chemist to 

 the War Department, Ac. 



(b) " Some of the Dangerous Properties of Dusts." By F. A. Abel, C.B., F.E.S. 

 A lecture delivered at the Royal Institution of Great Britain, on Friday, 28th 

 April, 1882. 



" The Explosive Properties of Coal-dust, Coal-gas, and Atmospheric Air, with 

 special reference to Mines." By C. E. Jones, F.R.H.S., Chesterfield. Read before 

 the Manchester District Institution of Gas Engineers on the 24th of February, 

 1883. 



|| " Annale* des Mines," Ire livraison, 1882. 



