718 Transactions of the American Institute. 



Boilers; H. Birdsall, Inspector of Boilers; B. B. Davenport, reporter 

 for the New York Herald ; J. B. Collin, Mechanical Engineer of the 

 Pennsylvania Central Railroad; Coleman Sellers, President of the 

 "Franklin Institute," Philadelphia; Dr. Wm. H. Wahl, Jr., Secre- 

 tary of the " Franklin Institute," Philadelphia ; Professor Jacob 

 Naylor, of Philadelphia; "Wm. N. Henderson, of Philadelphia, 

 mechanical engineer; E. H. Shallcross, of the Select Council of 

 Philadelphia; Wm. Fisher Mitchell, of Philadelphia; Thomas J. 

 Lovegrove of Philadelphia ; B. H. Thurston, Professor of Mechanical 

 Engineering, " Stevens' Institute," Hoboken ; A. Fletcher, W. 

 Fletcher, builders of steam-engines and boilers at New York ; C. H. 

 Haswell, Examiner of Steam Machinery for the New York Insurance 

 Companies ; Norman "Wiard, John McCurdy, James Miller, Messrs. 

 Phinney & Hoffman ; David Saunders, of the firm of J. Nason & 

 Co., New York ; Erastus W. Smith, mechanical engineer ; W. E. 

 Worthen, mechanical engineer ; Bobert Allen, 'Ralph Walker, G. H. 

 Clemens, John Stuart, C. M. Bolen, T. S. Crane, John Dunham, 

 Andrew Fife, John Fish, John McGowan. 



The first experiment was made on a boiler built by Fletcher, 

 Harrison & Co., in 1858, and taken out of the steamboat Joseph 

 Belknap, in July last, after hav ing been thirteen years in use. It is 

 of the ordinary upper return fine type, with a rectangular front seven 

 feet eight inches long, six feet six inches wide, and six feet eleven 

 inches high, containing two furnaces, each of which was two feet nine 

 inches wide and seven feet long ; the top of this front is semicircular 

 and single riveted. The remainder of the shell is a cylinder of six 

 feet six inches diameter and twenty feet four inches length, unbraced, 

 single riveted, and with a flat end. The total length of the boiler is 

 twenty-eight feet. The iron of which the shell is composed is a large 

 quarter inch thick, and all the flat surfaces are braced every seven 

 inches. The top of the furnaces is flat and braced to the semi- 

 circular top of the shell immediately over it ; and from this 

 semicircular top there rises the usual cylindrical " steam-chimney " 

 or annular steam-drum surrounding the lower portion of the chimney 

 and braced to it. The steam-chimney is four feet in external dia- 

 meter, two feet eight inches in internal diameter, and ten feet nine 

 inches in height above the shell. The lower flues are ten in number 

 and fifteen feet nine inches long ; two of them are sixteen inches in 

 inner diameter, and the remainder are nine inches in inner diameter. 

 The upper flues are twelve in number, twenty-two feet long, and 

 eight and a half inches in inner diameter. The least water-space 



