191i] on Surface Combustion 45 



to Avhat I conceive as occiUTing when an incandescent surface is 

 employed to accelerate ordinary gaseous combustion ; the action is so 

 concentrated at the surface that a substantially " flameless " effect 

 results. I want to emphasize the fact that the incandescent solid 

 plays a specific role in this surface combustion ; it is no mere idle 

 looker-on at the surging crowd of reacting molecules which swarm 

 around it. On the contrary, it so galvanizes and incites the dormant 

 affinities between the combustible gas and oxygen, that the stately 

 minuet of ordinary combustion gives place to the wild intoxication of 

 the Yenusberg. 



The manner in which the surface acts is still perhaps a 

 matter of conjecture, but the fact that it so acts can no longer 

 be disputed. In a discussion which took place at the British 

 Association in 1910, Sir J. J. Thomson insisted that combustion is 

 concerned not only with atoms and molecules, but also with electrons, 

 i.e. bodies of much smaller dimensions and moving with very high 

 velocities, and suggested that in reference to the influence of hot 

 surfaces in promoting combustion it was not improbable that the 

 emission of charged particles from the surface was a factor of primary 

 importance. It is known that incandescent surfaces emit enormous 

 streams of electrons travelling with high velocities, and the actions of 

 these surfaces in promoting combustion may ultimately be found to 

 depend on the fact that they bring about the formation of layers of 

 electrified gas in which chemical changes proceed with extraordinarily 

 high velocity. 



The New Processes of Incandescent Surface Combustion. 



Leaving the theoretical aspects of the subject, I will now describe 

 some of the more important features of two processes of incandescent 

 surface combustion evolved at the works of Messrs. Wilsons and 

 Mathiesons, Ltd., in Leeds under my direction, with the assistance 

 of Mr. C. D. McCourt, in which a homogeneous explosive mixture of 

 gas and air, in the proper proportions for complete combustion (or 

 with air in slight excess thereof), is caused to burn. without flame 

 in contact with a granular incandescent solid, whereliy a large pro- 

 portion of the potential energy of the gas is immediately converted 

 into radiant form. The advantages claimed for the new system, 

 now known as the "Bonecourt" system, are : (1) the combustion is 

 greatly accelerated by the incandescent surface, and, if so desired, may 

 be concentrated just where the heat is required ; (2) the combustion 

 is pei-fect with a minimum excess of air ; (3) the attainment of very 

 high temperatures is possible without the aid of elaborate regenera- 

 tive devices ; and (4) owing to the large amount of radiant energy 

 developed, transmission of heat from the seat of combustion to 

 the object to be heated is very rapid. These advantages are 



