228 
MINUTES OE PROCEEDINGS OP 
It will be seen that at that period I purposed placing the mortar, without 
any bed, directly against a platform formed of three layers of crossed 
baulks, bedded at a slope of about 45° against a bank scarped into the 
ground. 
The chamber is shown smallfor my earliest notion was that these mortars 
could be established within a few hundred yards, and that by a very small 
charge these great shells could be easily “ lobbed" in over the parapets of 
Sebastopol. The construction shown presents essentially, however, every 
feature to be found in the design as carried out. 
The cast-iron chamber and base are ringed with wrought-iron, shrunk on. 
The chase, in three segments, consists of two plies of wrought-iron rings— 
the outer shrunk or driven down upon the conical inner ones, and all held 
together by eight longitudinal bolts, hooked over the muzzle. This design 
was exhibited by me in December, 1854, to Captain Boxer, B.A., to the late 
Colonel Portlock, R.E., and to several other authorities at Woolwich. 
I am not aware that any design for the adoption of ringed structure with 
initial tension to ordnance, with a clear conception of its value, can be 
shown to have been produced earlier than this. As to the late Captain 
Blakely's claims, I refer, for the complete refutation of them, both as respects 
Dr. Hart's, E.T.C.D., priority in mathematical investigation of the laws, 
and my own priority to the method itself of “ringed structure," to the 
“Proceedings of the Boyal Irish Academy," Yol. Y1I. p. 316, et seq., May 
and June, 1860. 
Mr. Longridge's, C.E., wire-wrapped gun dates, I believe, from early in 
1855 ; and Professor dread well's, United States, claim as a proposer of 
“ ringed structure," by a letter in my possession from himself, dated 
Cambridge, U.S., December 3, 1857, dates from Eebruary, 1856. The 
late Mr. Brunei's communications to Sir W. Armstrong would appear, from 
the biography of the former, lately published, to date from April, 1855. 
(Life of I. K. Brunei, Civil Engineer. By his Son, Isambard Brunei. 
London, 1870, p. 453.) Letter to James Nasymth, April 1855 :— 
ec A cylinder of hardish material, wrapped round with iron wire, laid on with a 
certain amount of tension proportioned to the diameter—such a barrel ought to 
be strong; whether practically successful is another thing." 
Mr. Armstrong's earliest gun in ringed structure was, I believe, posterior 
to the design and even to the construction of the mortars. 
Captain Tierry, of the Erench artillery, in a work published as early as 
1834, appears to have been the earliest to propose strengthening cast-iron 
guns by wrought-iron rings shrunk upon their exterior in one ply. He 
does not show himself, however, to have clearly grasped the value of the 
principle of initial tension, as distinct from a mere superposition of addi¬ 
tional material, which alone was the notion of the’fabricators of the ancient 
ringed “ bombards," thus constructed by them as a matter of necessity. 
Early in January, 1855, I had seen the importance of being able to 
employ these mortars at sea, and with greater convenience and with extended 
ranges on land, and therefore designed a movable bed for them, with means 
for altering the angle of elevation, &c. 
My first communication as to those mortars, accompanied by a rather full 
memoir on the powers of 36-inch shells, was laid before the Ordnance 
