CEITICAli NOTICES OF NEW PUBLICATIONS. 317 



be prevalent among engineers on the western waters of the United 

 States, that, provided a full supply of water is kept in a boiler, there 

 is no danger of explosion from increasing the steam pressure.* 



To set this question at rest, two cylinders — one of iron and one of 

 copper — were partly filled with water and exposed over a fire, so as 

 to increase the pressure of steam within ; the greatest amount of this 

 pressure, before the cylinder gave way, being registered by a spring 



gauge. The material facts attending the bursting of the iron boiler 

 are thus stated by the Committee : — 



" The explosion tore off one of the heads, b c, of the cylinder, projecting 

 the other parts of the boiler in an opposite direction, carrying with them, for 

 a portion of the distance, the iron cylinder forming the furnace, and scatter- 

 ing the fuel in every direction. * * The boiler head was thrown fifteen 

 feet, the boiler and spring register about six feet, and the furnace, weighing 

 about forty-five pounds, was overturned and carried four feet. The pressure 

 indicated by the register was ll^ atmospheres. * * The circumstances 

 of this experiment show that the steam rose quite gradually on account of 

 leaks in the boiler, increasing, probably, more rapidly as the quantity of wa- 

 ter diminished, the intensity of the fire, meanwhile, increasing ; that, at a 

 certain period, the tension within had attained about eleven atmospheres, when 

 the boiler exploded violently.'''' 



The copper cylinder was next subjected to experiment : 



'• As before, nothing remarkable occurred previous to the instant of ex- 

 plosion, and the members of the committee employed in the experiments 

 were engaged in observing the boiler at the instant it exploded. A dense 

 cloud of smoke and flame, capped by steam, rose from the pit ; the stones 

 and combustibles were widely scattered, and the boiler was thrown, in a 

 smgle mass, about fifteen feet from the furnace. The noise attending this 

 explosion was like that from the firing of an eight inch mortar. 



" The boiler was rent as shown in the accompanying figure, giving way in 

 an irregular line, just above the probable water-line on one side of the boiler, 

 but not conforming to it. d and b were the lowest points in the two heads 



• This same opinion we see in the evidence of one of the parties examined 

 before the coroner's inquest in relation to the late accident at Hull. 



