MEMOIR OF DAXIEL TREADWELL. 457 



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



December 11, 1855. It is dated February 4, 1862. 



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

 about twice as great as the calibre intended to be boi'ed in it. I then l)ore it and turn the out- 

 side, mailing two or three cylinders as represented at A, A, in the drawing ; one of these cylin- 

 ders extending from the breech to a little beyond the trunnions, being somewhat larger than the 

 others, that extend from near the truiuiions to the muzzle. Upon these cylinders I cut a screw 

 formed of about eight threads, caeli thread taking about one eiglith of an inch space, so that one 

 turn advances each thread about one inch. I then form several lioops or rings of wrought iron, 

 represented at B, B, B, etc., in section. These hoops arc turned upon the inside, and have a 

 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 place or 

 places, as shown in the drawing. It will be seen that the hoop marked B must be first put in its 

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

 hoop B', that partly covers it, can be put in its place. When one cover of hoops (B, B, B, etc.) 

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

 outside of these first series of hoops, and cut thereon a screw of several threads, as was before 

 done on the cast-iron body. I then form another set of hoops (C, C, C, etc.), with female 

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

 thousandth part less than the screw tliey are to cover. I expand them by heat, as was practised 

 with the first set, and let tlicni shrink on in place, as they are shown in the drawings. One of 

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

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

 of twelve inches' calibre." 



We give here the following letter from Captain Blakelj, with Mr. Treadwell's 

 reply, in conclusion of this subject. 



To Daniel Treadwell. 



24 Wilton Place, London, r)ocpm'bpr 1, 18.58. 



Dear Sir, — I am going to read a paper to the United Service in January about our method 

 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 years, 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. Ncitlier in the materials used nor in the method of manufaetnre, were the conditions 

 obtained essential to secure the qualities of heavy guns constructed according to the Treadwell [iroeesses. The results 

 were most unsatisfactory ; eiglity-six burst in the service, besides eighteen hundred-pounders unaccounted for, sup- 

 posed to be hurst, results widely different from tliose of the European manufacturers, who have intelligently and skilfully 

 used Treadwell's methods. Sec Mr. Howard's Keport of Joint Committco on Ordnance to Senate, February 15, 1809, 

 page 217. 



