374 Dreadful Accident in Well- Street. 



with it. The very idea of proving (he boiler with steam sa.- 

 voured of insanity; for, if too M-eak, it could do nothing but 

 explode. What would be said of tlie man who should seek to 

 ascertain the lowest heat at which, gun-powder would explode, 

 hy thrusting in succession into a barrel of that article, bars of 

 iron heated to different degrees of temperature ? 



When a large boiler is to be employed to generate steam of high 

 temperature, it should be proved, not with water and a fire applied 

 to it, but with cold water forced in by a pump or syringe till the 

 boiler has been subjected to move than twice the pressure to 

 which it is intended it shall ever be exposed with steam. The 

 most accurate way to ascertain the pressure is by a tube of suf- 

 ficient length connected with the boiler, and containing mercury. 

 Should a boiler subjected to this test prove too weak, it only 

 rends at the weak part — no explosion takes place, and no one 

 can receive any personal injury. 



We went to the ruins on the 20th of November, and ascertained 

 several facts, indicating in our opinion cither great ignorance or 

 great carelessness on the part of those who had the care of con- 

 structing the boilcrand pans. In tbe first place, as to the form of 

 the boiler itself, — it was somewhat globular, with a concave bot- 

 tom, and of no less than eight J'cet diameter*. For generating 

 strong steam, boilers composed of tubes of comparatively small 

 diameter should alv.ays be employed ; for the strength ceteris 

 paribus is inversely as the scpiares of the diameters of the vessels 

 compared. The best, indeed the only boiler with which we are 

 acquainted, that can with safety be employed for such a pur- 

 pose, is Woolf 's, composed of tubes: The substance of the 

 boiler which we saw in Well-street, was in no part two inches — 

 in some parts not more than one inch. In other words — a boiler 

 made for the purpose of generating steam of a pressure of 40 or 

 50 pounds per inchf, and not exceeding an inch in thickness, 

 (for the greater thickness in some ])laces goes for nothing in 

 such a case as this,) and eight feet diameter, was set to work 

 without even its substance (so far as we could learn) having 



* Tlif f] agment vvliich we saw fpeiliaiJS about a fi)urth of the wliole 

 boiler) \\a.(\ lieen removed about twenty feet from its original position into 

 another apartment, from wiiich it hari bctbre been separated by a brick 

 wall. 



f It cannot he afcertaintd to what pressure the boiler had attained when 

 the txplo.'-ioii took jilacc. Mr. Constant saw the s^uge a few minutes be- 

 fore, tmJ It vviis then under 40 pounds pt r inch: one of the workmen saw 

 it at 46. I'/om the weakness of the boiler. It is not probable that the 

 pressure was luui h beyond the latter point when the boiler exploded; but 

 from the great accumjlation of heat in the substance of the boiler, in the 

 furnace and in the surrounding materials an instant generation of a new 

 quantity of steam would be produced by the liberated water, 



been 



