110 ANNUAL OF SCIENTIFIC DISCOVERT. 



bei^inning of the sixth volume of oiu* 'Memoirs.' This was the 

 first i)iil)lish(Ml account of the invciilioii, wliich hud been ])atented 

 neaily a year Ijeibre, Captain Bhikely\s pamphlet, puljlished in 

 Enijland in 18u8, sets fortli the advantages of tins construction l^y 

 simihir arguments ; as also does an elal)orate paper read by Mr. 

 Longridge before the Institution of Civil Engineers in February, 

 18G0. lioth these gentlemen, however, were engaged in researches 

 upon this subject at an earlier date, but not so early, it would 

 ajjpear, as was Mr. Tread well. 



" The validity of the principle, and the soundness of Mr. Tread- 

 well's views ujion the whole subject, as set forth in his memoir, 

 have beea amply confirmed by special experiments made in 

 England with the'Blakely and Wliitworth guns, and by experience 

 in tliis country, during the last four years, witJi the Farrott and the 

 Blakely guns. 



" It must not be supposed that the earlier invention is superseded 

 by the later one. That is usi'd in forming the hoops of the Farrott 

 gnn, and in most of the British guns. And the best gun which 

 could now be made, as experience has shown, would be composed 

 of a barrel of cast-iron or steel, inclosed and compressed by a 

 cylinder of coil. 



"We need not discuss the question of priority of inviention be- 

 tween i\lr. Treadwell and others, comi)etit(<ics for a share in the 

 honor of producing the modern cannon. Ilis independence of 

 each and all of them has never been called in question. Nor will 

 it ever seriously be thought that the previous fntile attempts at 

 constructing wrou<i:ht-iron and banded guns — Ibredoomed failures 

 both in theory and i)raetic(!, and destitue of all pretension to a 

 knowledge of the guiding principles now clearly seen to be essen- 

 tial to success — should detract in the slightest degree from the 

 great honor which our associate has, by a clear insight into the 

 conditions of the i)roblem and the resources of physical science, 

 so fairly and comi^letely won. 



" Upon these two inventions has been set the seal of experience. 

 But there is anotiier memoir, read iiy Professor Treadwell before 

 this Academy in April, 18G4, and printed soon afterwards, which 

 promises to add a third important improvement in the construc- 

 tion of artiller}'. 



" Ferceiving that the body of a hooped gun, if made of unmal- 

 leable cast-iron, compressed by a soft wrought-iron hoojj, must give 

 way, by the fracture of the cast-iron hoop, before the hoop can 

 approach the ultimate limit of its strength, and that this was, in 

 fact, a principal cause of the failure of so great a pait of the large 

 guns of Blakely and Farrott, Frofessor Treadwell, as the jirincipal 

 result of this third investigation, proceeds to show, that, to attain 

 with effect the end sought for hy hooping a cast-iron gun, it is 

 necessary to harden the wrought-iron hooj} by cold hammering 

 and severe stretching before placing it upon the gun-bod}'. He 

 computes that, by this simple means, a hooped gun may be made 

 more than twice as strong as those which have been constructed 

 by Klakely and Farrott, the materials being in both cases the 

 same. 



