42 Professor W. A. Bone [Feb. 27, 



surface ; Faraday, on the other hand, contended that the function of 

 the surface is to condense both the oxygen and the combustible gas, 

 thus producing in the surface layers a condition comparable to that 

 of high pressure. But, owing to lack of crucial experiments, no 

 satisfactory theory of the phenomenon could be evolved, nor, with 

 the exception of the famous " Dobereiner Lamp," was there any 

 practical outcome of this early work. In 1836 interest in the subject 

 suddenly dropped, and was not revived for half a century. 



^Meanwhile, the researches of Deville upon the dissociation of steam 

 and carbon-dioxide at high temperatures led to the notion, which was 

 strongly upheld by the late Frederick Siemens, that inasmuch as 

 incandescent surfaces promote dissociation, they must necessarily 

 hinder combustion. This, of course, is fallacious ; we now recognize 

 that if, as Deville proved, an incandescent surface accelerates the 

 dissociation of steam, it must, according to a principle enunciated by 

 Ostwald, of necessity accelerate the combination of oxygen and 

 hydrogen in like degree, provided always that the surface remains 

 chemically unaltered. 



A notable demonstration of the possibility of realizing flameless 

 incandescent surface combustion in contact with metals other than 

 those of the platinum group was given by Thomas Fletcher in a 

 lecture at the Manchester Technical School as far back as 1887.* He 

 injected a mixture of gas and air on to a large ball of iron wire, 

 flame being used at first in order to heat the wire to the temperature 

 necessary to induce a continuous surface combustion ; on extinguish- 

 ing the flame, by momentarily stopping the gaseous mixture, the com- 

 bustion continued without any flame, but with an enormous increase 

 of temperature. Fletcher grasped three important points, namely : 

 (1) that ''this invisible flameless combustion is only possible under 

 certain conditions," (2) " that the combustible mixture shall come 

 into absolute contact with a substance at high temperature. . . ," 

 and (3) that " in the absence of a solid substance at a high tempera- 

 ture, it is impossible to cause combustion without flame " ; but, so far 

 as I am aware, he did not follow up the matter beyond this point, 

 either in its theoretical aspects or practical applications, and his work 

 had but little influence upon contemporary opinion or practice. 



My own investigations upon surface combustion began in 1902 

 with a systematic attempt to elucidate the factors operative in the 

 slow combination of hydrogen and of carbon monoxide in contact 

 with various hot surfaces (e.g. porcelain, fire-clay, magnesia, plati- 

 num, gold, silver, copper and nickel oxides, etc.) at temperatures 

 below 50(V.* Into the details of these earlier experiments, which 

 preceded and led up to the technical developments about which I 

 shall speak later, I do not propose to enter ; it will be sufficient for 

 my present purpose if I say that it was proved beyond all question 



* Journal of Gas Lighting, 1887, i. p. 168. 



