420 



MEMOIR OF DANIEL TREADWELL. 



and when the gun is trained, I understand, the strain is brought on a single part of the breech- 

 ing; these are serious, if not fatal objections. 



Wad 



gun-carriage. Unless the objections therein stated can be overcome, I do not feel justified in 



armament 



A. v * »_> 



I am, very respectfully, your obedient servant, 



W. M. Crane. 



To Commodore Crane. 



Sir, — I have received 3 



Cambridge, September 10, 1845. 



Commander "Wadsworth's renor 



— 



the trial of my gun-carriage, and beg leave to lay before you some observations on the objections 

 made to the carriage by Commander Wadsworth and embodied in your letter. These are, first, 

 to the tongue under the carriage for directing it to the middle of the port. Now, this tongue 

 does not extend farther from the side of the ship than through the space over which the cannon 

 recoils, and it may be shortened at least a foot more. It extends to a less distance than the 

 check pieces or slides upon which the carriages lately made, I think, for the Marion extend, and 

 does not take up half so much room upon the deck. Moreover, it is intended to be unshipped 

 and laid aside when the gun is not in use. If, however, it is considered objectionable, it may be 

 taken entirely away, and the carriage can be left to work without it in precisely the same man- 

 ner that a common carriage works, without diminishing in the least degree the effect of the 

 apparatus for preventing the recoil, as it has nothing whatever to do with holding the gun against 

 the recoil, but merely directs it to the middle of the port. 



For the second objection enumerated by you from Commander Wadsworth's report, that the 

 strain when the gun is trained forward or aft is brought upon a single part of the three-inch 

 rope of which the band is formed, I have to say that, but for a severe illness which prevented me 

 from being present at the experiments and explaining to Commander Wadsworth the method 

 by which I intend to fix the band to the side of the ship, this objection would not, I am sure, 

 have been made, as I should have shown that it is intended to fix the band on shipboard to 

 an eye-bolt upon which it can swivel in all directions ; whereas in the experiments made before 

 Commander Wadsworth it was attached to a dynamometer for the purpose of showing the 

 exact force of the recoil. By this mode of fixture, the strain under the conditions stated in 

 the report becomes unequal upon the different parts of the band. But when fixed, as intended 

 on shipboard, to an eye-bolt, the objection will be entirely obviated, and the strain must under 

 all circumstances be equally diffused upon the band. I hope that this explanation will be 

 thought by you sufficient to warrant the conclusion that neither of the principal objections con- 

 tained in your letter can be taken to remain against the carriage. 



Permit me further to observe concerning Commander Wadsworth's report, that, while he 

 enumerates the liability of the friction-plates to be broken, and likewise that these and the side- 

 wheel will be likely to catch the rigging in working the ship, he makes no mention whatever 

 of the great amount of tackle necessary to the old carriage, but not required in this. Indeed, 

 I cannot but think that, on reflection, he will be sensible that the deck of the ship furnished 

 with these carriages will be much less encumbered with ropes and blocks, over which the men 

 must pass, than the deck which bears the common apparatus as now used. I certainly thought 

 that this fact, and the less number of men required to work the carriage from the ease with 

 which it is moved, ought to be taken as circumstances much in its favor, and I cannot but 

 lament that they have escaped Commander Wadsworth in his reDort. 





