MEMOIR OF DAXIEL TREADWELL. 457 



The following is the specification of the reissue of the IVesdwell patent of 

 December 11, 1855. It is dated February 4, 18C2. 



"I first cast a cannon in the usual manner, but having in its largest part a diameter oalj 

 about twice as great as the calibre intended to be boivd in it. 1 then bore it and turn the out- 

 side, making two or three cylinders as represented at A, A, in the drawing : one of these lin- 

 ders extending from the breech to a little beyond the trunnions, being somcwhal larger tin, tho 

 others, that extend from near the trunnions to the muzzle. Upon those cylinders 1 cut a screw 

 formed of about eight threads, each thread taking about one ei hth of an inch space, so thai on.) 

 turn advances each thread about one inch. I then form several hoops or rii 

 represented at B, B, B, etc., in section. These hoops are turned upon th 



■> 



female screw cut upon their inner surface to fit the thread before described as cut upon the 

 cast-iron cylinders forming the gun body. They are to be finished, however, about one thou- 

 sandth part of their internal diameter less in diameter than the male screw that they are to 

 encircle. They are then heated to expand them sufficiently to turn them on to their pUu >r 

 places, as shown in the drawing. It will be seen that the hoop marked I! must be lii : put in it 

 place and a portion of its outer side turned, and have the threads formed upon it before tho- 



. hoop B', that partly covers it, can be put in its place. 



< K, H. H,etc) 



is arranged as herein described and shown, I place the gun again in the lathe, and turn tho 



before 



done on the cast-iron body. 



(C, C, C, etc) 



screws corresponding to the male screws upon the first series, and the diameter being one 

 thousandth part less than the screw they are to cover. I expand them by heat, as w practi I 

 with the first set, and let them shrink on in place, as they are shown in the drawing*. < hie of 

 these hoops has the trunnions forged upon it, as shown at I». D. It will be noticed that the 

 series C, C, break joints over B, B. The proportions in the drawing are intended for a cannon 



of twelve inches' calibre." 



We give here the following letter from Captain Blakely, with Mr. Tread well's 

 reply, in conclusion of this subject. 



To Daniel Treadwell. 



24 Wir/rox PLACE, LOWKW, December 1, 1858. 



Dear Sir, 



am 



of making cannon. Can you oblige me with any detailed account of experiments carried out 

 with it in America by yourself or others ? If so, you will greatly oblige me. I need hardly say 

 that I shall duly acknowledge to whom science owes the experiments. 



Our Government has now had an eight-inch and a ten-inch gun made for two y ra but 

 has not tried either yet. However, the experiments will soon commence now. The French have 

 tried a thirty-two pounder, but did not put on the rings tight enough. However, the result even 



port to the cast-iron body. Neither in the materials used nor in the method of manufacture, w « the edition 

 obtained essential to secure the qualities of heavy gnna constructed according <;• the T, tdwell pn . . h 



were most unsatisfactory; eightv-six burst in the sen-ice, besides eighteen huudred-pounde, n - n dfor aup 

 posed to beburst, resulte widely different from those of the European manufacturers, who have mtelb ££*£™ 

 used TreadwelPs methods. See Mr. Howard's Report of Joint Committee on Ordnance to Senate, Febmarj 15, 1 , 



page 217. 



