ORIGIN OP 



force must have been in operation ; yet with all the skill and 

 knowledge of the scientific world it has evaded their research; 



In the United States, Congress appointed commissioners to 

 investigate the cause of boiler explosions, and allowed them 

 $50,000 for making experiments, but after expending half the 

 amount, the only discovery reported to be made, is, that the 

 steam guages in use are very incorrect. 



Before showing how chemical action is their cause, we will 

 present a few of the facts connected with boiler explosions, culled 

 from numerous accounts of them in the newspapers. 



1. Kew boilers are more frequently found to explode than old 

 ones. 



2. The explosion of a steamboat or locomotive boiler almost 

 always takes place on its starting, after having been waiting 

 for some time. Our readers may remember the terrible West- 

 ville explosion of one of Com. Vanderbilt's Staten Islands' 

 steamers, which Was just leaving the wharf at New York, when 

 the boiler burst. 



3. The explosion in a stationary boiler takes place, when 

 what is called a heavy pressure of steam is put on. 



Let us now examine the nature of the material we have to 

 deal with. In the first place there is the boiler made of iron. 

 An old boiler has generally an inside coating of rust or sedi- 

 ment, which is more or less composed of vegetable matter, 

 caused by chemical action between the water and the iron; 

 whereas a new boiler has a surface of pure metal, together with 

 the scrap iron from its manufacture. 



The water which is used in the boiler is composed of two 

 gases oxygen and hydrogen in certain proportions. It is 

 Well known also that if those gases are mixed in a certain but 



