Polytechnic Association. 717 



ance of the following resolutions, passed on the 11th of September 

 last, by the executive committee of the United Railroad Companies 

 of New Jersey, namely : 



" That in order to attain greater safety in the steam boilers belong- 

 ing to the United Companies, Mr. F. B. Stevens be authorized to 

 continue the experiments on the strength and proper management of 

 such boilers, and for this purpose to expend not exceeding $10,000, 

 the vouchers for which to take the ordinary course. 



" That other owners of steam boilers are hereby invited to contri- 

 bute to the experiments to be made by Mr. Stevens, and that the 

 wharf, shops, derrick and tools belonging to the United Companies 

 at Hoboken may be used for this purpose, at cost prices, and a copy 

 of the charges given by the auditor to the contributors. 



" That Mr. Stevens be advised to invite the United States inspec- 

 tors and other prominent engineers to be present at the experiments." 



On the 20th of September last, Mr. Stevens received permission 

 from the Secretary of War, at the instance of the President, to make 

 the experiments on the government reservation at Sandy Hook, and 

 to that place he transported the experimental boilers, with the neces- 

 sary instruments, material and shed accommodation. 



The boilers to be experimented with were nine in number ; they 

 were conveniently arranged on a well chosen piece of ground inclosed 

 by a high board fence, and were provided with the requisite pressure 

 and water gauges. The former were expressly manufactured for the 

 occasion, and had been carefully tested. Five pressure-gauges were 

 placed near each boiler tried, under the protection of two bomb- 

 proof; and two, tested to a pressure of 500 pounds per square inch, 

 were placed side by side, at a safe distance from the boilers (about 250 

 feet on the first day, and 450 feet on the second day of the experi- 

 ments), with which they communicated by a pipe of suitable length ; 

 while in this position their indications were compared with those of 

 the tested pressure-gauges at the boilers, and found to agree. All of 

 Mr. Stevens' arrangements were judiciously made, and nothing was 

 wanting to their accuracy and completeness. 



Experiments of the 22d of November, 1871. 

 On the 22d ultimo, in accordance with a notification from Mr. Ste- 

 vens, we proceeded to Sandy Hook, and witnessed the first experi- 

 ments, in company with the following gentlemen, who are largely 

 interested, practically and scientifically, in the design, construction 

 and use of steam boilers : Joseph Belknap, Inspector-General of 



