ON THE CONSTRUCTION OF HOOPED CANNON. 45 



IV. 



On the Construction of Hooped Cannon ; Icing a Sequel to a Memoir " On the Practicability 



Constructing Cannon of Great Caliber, dec." published in the Vllh Volume of ih 



Memoirs of the Academy. 



Br DANIEL TREADWELL, 



LATE RCMFORD PROFESSOB IH HARVARD UNIVERSITY. 



Communicated April 12th, 18G4. 



Although a great improvement lias been made in the construction of cannon 

 by the adoption of the principle, and imperfectly the mechanical form, indicated 

 by me in a specification of June 19th, 1855, which was immediately afterwards 

 expanded into the memoir published in the Vlth Volume of the Academy's 

 Memoirs;* still many points in the theory of that construction remain not only 

 unperfected, but almost unexamined. 



It is my purpose, therefore, in this paper, to investigate several important prop- 

 erties and laws which are inherent in the materials of which the gun described 

 in my former memoir is constructed j and from this investigation I shall endeavor 

 to draw such instruction as will enable us, if not to perfect, at least to under- 

 stand and improve, the theory of construction. The investigation will be founded 

 almost entirely upon certain peculiarities in the nature, character, and properties 

 of the materials (wrought-iron, cast-iron, and steel) of which the guns, constructed 

 upon the principle heretofore published by me, are formed. 



With these preliminary remarks I enter at once into the proposed inquiry, leav- 

 ing the development of the course to be pursued to appear as I proceed. 



In the memoir of 1855, before referred to, in giving an account of the theory 

 of hooping cannon, I inserted the following paragraph (p. 10) : 



The memoir in the Vlth Volume must be considered as a sequel to, and a further development of, 

 the principles contained in a publication, in the form of a pamphlet, made by me in 1845. In this 

 pamphlet, not only the principles, but the method of construction since followed by Armstrong and others, 



are fully pointed out. 



VOL. IX. NEW SERIES 



7 



