432 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



by hostile guns. The lightest of its projectiles, the one with the hol- 

 low rear, weighs 780 lbs. When this shot is used, the cubical contents of 

 the bore and the hollow base of the shot are about six times the cubical 

 capacity of 60 lbs. of fine powder, and that charge would thus be well 

 utilized, giving a respectable velocity to the greater weight of projectile 

 than has ever before been thrown. No ship can be made to carry plating 

 that will resist it, except its size is so great that it cannot enter any 

 of our harbors. 



These guns, adapted to such tremendous projectiles, can then be mounted 

 in turrets of such thickness of iron as to resist projectiles from any other 

 gun now made, or likely to be made, if the turret rests on a solid founda- 

 tion, as in the fort proposed for harbors; and will afford absolute protection 

 to them without involving extravagant cost of either money or material. 

 The accelerating gun described is available for fast wooden or iron steam- 

 ships, and, from the extraordinary velocity they impart to the projectile, 

 will penetrate iron-clad ships at very long ranges 



The cheap cast iron gun completes the list, and is available for other 

 requirements of service, for which large calibers are desirable, and as the 

 principles involved in my statements only affect large guns, I shall discuss 

 the subject of small guns at another meeting. 



Adjourned. Thomas D. Stetson, Secretary. 



American Institute Polytechnic Asssociation, \ 

 December 26, 1862. ' j" 



The Chairman, S. D. Tillman, Esq., presiding. 



Mr. J. H. Churchill alluded to the difference of gases, and thought the 

 fact that two gases in separate chambers would each expand into the other 

 without change of heat, proved the truth of the dynamical theory of heat. 



Prof. Seely, Mr. Dibben and Mr. Bartlett differed from him, and thought 

 the action was a mere mixture and not properly an expansion of either gas. 



Mr. J. K. Fisher doubted the theory that the gases would intermingle so 

 rapidly as each gas would flow into a vacuum. 



The Chairman read from the Transactions of 1851, the report of his re- 

 marks made on June 10, of that year, on the practicability of a telegraph 

 to Europe by way of Behring's strait. He added that news has now arrived 

 that the Siberian portion of the line is now being rapidly progressed with; 

 a line has been nearly completed from St. Petersburg eastward to the 

 Amoor river, while our own lines have been extended to the Pacific. 



The regular subject, " Improvements in Modern Warfare," was then 

 taken up. 



The SecretaiT explained some of the recent improvements in fuses which 

 have been lately invented and introduced Avith success for rifles, cannon 

 and shells. 



He described and explained particularly Schenkl's fuse, already largely 

 introduced into the service. 



Mr. J. K. Fisher said that it is shown by recent reports, that the Whit- 



