Polytechnic Association. 691 



tremendous force, prostrating almost the entire four stories of the 

 building to the ground. Parting in the middle, one portion was 

 blown 200 feet, tearing a large hole in a wall of a cotton mill, which 

 stood near. Two persons were killed and twenty wounded by the 

 explosion. 



The writer, who published an account of the disaster, remarked 

 that the theory of the water flashing into steam and causing an explo- 

 sion was not applicable here, for there was no water in this bleacher. 

 The water was in the boiler in another apartment on a lower floor ; 

 that boiler did not explode. We regard this instance (and another 

 similar one has been recently reported) as settling the theory of the 

 water suddenly flashing into steam, independently of the other facts 

 in many of the narratives of explosion tending to the same conclu- 

 sion. But his theory of the cause, from " a steadily increasing press- 

 ure " of the steam, is scarcely more satisfactory. A steadily increas- 

 ing pressure might well account for the rupture of this bleacher and 

 the escape of the steam, had such been alone the circumstances of 

 the case ; but can it be conceived how a steadily increasing pressure 

 could have exploded it with such enormous violence, breaking it 

 asunder, demolishing a new four-story brick building, casting one 

 portion of the bleacher 200 feet against a mill and breaking a great 

 hole in its wall ? On the contrary, is it not manifest that these were 

 the effects of an explosive force, a suddenly expansive power like that 

 of gunpowder touched with fire, acting not with a strain, but with 

 the irresistible energy of a mighty blow ? 



The reports of explosions represent the ruined boilers in various 

 conditions of dilapidation. In some, the shell or case is only rup- 

 tured, or the head opened or forced out, or the flues collapsed with- 

 out the boiler being lifted from its position. In such cases, we have 

 the legitimate effects of excessive pressure and easily conceive how 

 the steam acts to cause these results. 



The reports which are published of the examinations, usually made 

 of the causes of the violent and destructive explosions, are unsatisfac- 

 tory, both in regard to the conclusions of the committees and the evi- 

 dence submitted. We are always much disappointed in the explana- 

 tions given, on such occasions, by scientific as well as practical engi- 

 neers ; which are generally remarkable for diversity of opinion and 

 weakness of judgment. We have never seen anything in the reports, 

 or the testimony accompanying them, which afforded even a plausible 

 reason for the most disastrous and destructive explosions. The very 

 calamitous and recent instance — that of the Westfield steamer in New 



