690 Transactions of the American Institute. 



through the breach. But in this instance which we have detailed, 

 the walls opposite to each end of the boiler were prostrated, and while 

 the greater portion of the boiler, weighing three tons, was carried 

 700 feet north, the other end, a smaller portion, weighing about 300 

 pounds, was sent through the south wall forty feet from its position. 

 Had the explosion been caused by the gradually augmented strain of 

 the steam pressure, it is plain to our apprehension that this small 

 portion, though broken off from the rest, must have followed in its 

 flight, going north instead of south. We repeat, when the restrained 

 power of steam obtains an issue, the reaction of the boiler will tend 

 toward and favor the movement of all the parts in the direction in 

 which the steam issues. Now, the explosion of the boiler we have 

 described shows that the force was exerted in opposite directions, 

 and with an energy of immeasurable power. Three strong walls, 

 south, north and east, were thrown down, the roof torn to pieces and 

 scattered, and on the west side, the other boiler, weighing more than 

 three tons, was driven sideways through an eighteen inch brick wall. 

 It was a force radiating from the center, striking out on all sides like 

 a hundred-armed Briareus. There was no evidence of a reaction ; it 

 was a centrifugal, impulsive, irresistible action, overwhelming on all 

 sides every^ obstruction. 



We have alluded to the theory maintained by some, that the explo- 

 sions of steam boilers are often produced by the conversion of the 

 water in the boiler, by a sudden flash, into steam. But the process by 

 which water is converted into steam is well known. It commences 

 at the bottom of the boiler, or wherever the greatest heat is applied, 

 and ends at the surface of the water where the steam is evolved. 

 Rapid or slow in its formation, this is the course and progress of 

 steam manufacture ; arid we know not how it is conceived that water 

 ever flashes into steam, or, in other words, explodes like gunpowder. 



The explosion we mentioned of a boiler, in which there was no 

 water at the time, occurred in a paper mill belonging to Mr. J. M. 

 Black, of Marseilles, 111. It was a rotary steam-bleacher that exploded. 

 It was six feet in diameter, twenty feet in length, and was situated on 

 the floor above the boiler in which the steam was generated, and 

 almost directly over it. The pressure of the steam in the boiler at 

 the time of the explosion was eighty pounds to the square inch. The 

 steam was supplied to the bleacher by pipes entering at each end 

 through hollow bearings. At the time of the accident (the bleacher 

 being then first used and the mill new), there were 6,000 pounds of rags 

 undergoing the process of bleaching. The bleacher exploded with 



