706 Transactions of the American Institute. 



electric spark within the boiler would be rendered impossible, and no 

 explosion could take place. 



In the year 1842 the French government granted a patent to one 

 M. Tossin, of Liege, for an invention to prevent the explosion of steam 

 boilers, which, for some unknown reason, was revoked, in 1844. It 

 was an invention of metallic conductors introduced into the boiler 

 and armed with a sheaf of points, and connected exteriorly with a 

 Ley den jar and a bar of metal immersed in water or moist earth. 

 The position of the points was not precisely defined, nor did it appear 

 from his specification that he bad any knowledge of the peculiar action 

 of electricity by which it immediately spreads itself over the surface 

 of metallic boilers, or the least notion of the accumulation of explo- 

 sive gases within the boiler. He appears to have fancied that boilers 

 were exploded by electricity suo propria vigore. The invention 

 proved a failure under his patent, but it, nevertheless, from the 

 terms of our patent law, precluded, by anticipation, an applicant 

 in 1869 from obtaining a patent from the United States Commissioners 

 at Washington ; though the American invention was founded upon 

 the presence of accumulated gases within the boiler, the discharge of 

 the electric spark as above explained, and the placing of electric points 

 in proximity to the upper interior surface of the boiler. Under a 

 strong conviction of the truth of this theory (which, by the way, we 

 have partially demonstrated by actual experiments), we now submit 

 the same, from the sense of duty to the public, in the hope that some 

 one, with more leisure and better means, will institute a course of 

 experiments upon an adequate scale to prove, beyond all possible 

 doubt, that water is decomposed in the generation of steam in 

 steam boilers, and that it is the electric spark which explodes the 

 accumulated gases. 



The President — It has formerly been asserted that water in the 

 boiler is resolved into two gases by heat. This cannot be true, for it 

 requires, to thus decompose it, a higher degree of heat than is found in 

 the boiler. 



Mr. Blanchard — One point much dwelt upon in discussing the 

 cause of the explosion of steam boilers is the terrific force and sud- 

 denness with which they are exploded. And it is often said that if it 

 were simply from a gradually increasing pressure, a boiler would give 

 way at the weakest point. It is only good boilers which explode with 

 such destructive force, and they have no weak point. The gentleman 

 argues that if the boiler gave way from mere pressure within it, the 

 whole boiler would go in one direction. An apparatus could easily 



