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MINUTES OE PROCEEDINGS OE 
to a distance exceeding a mile and a half. This weight reached 2986 lbs.; 
• in the shells thrown furthest it was as much as 2400 lbs. 
3. The following paper is prepared from notes which have long been 
lying by me, extended by consulting the original records, and by information 
kindly given to me by Mr. Mallet himself, and Sir Charles Wheatstone, who 
in his then official capacity of member of the Ordnance Select Committee, 
took, as will be seen further on, an important part in the experiments. I 
propose to record the facts exactly, and then to see what conclusions can be 
based upon them. 
4. It will first be convenient to say something of the origination of the 
mortars—a matter which gave rise to a warm controversy between the late 
Captain Blakely and Mr. Mallet, in 1860, on the claim to priority by 
the former as the alleged inventor of “ringed structure” in guns* The 
latter gentleman expressed himself thus, in controverting the claims of 
Captain Blakely:— 
“ Now as to the dates of my own proceedings. The general principles of the 
construction of built-up guns—the fact that an enormous accession of strength 
could be attained by external rings with initial tension—were known to me from 
about the year 1850, and were first suggested to my mind by reading certain 
passages in Mr. Edwin Clarke’s book on the Britannia Bridge, where (Yol. I. p. 306, 
and note to p. 311) facts may be found containing the germ of the whole theory. 
I, however, gave no publicity to my notions until the year 1854. In October, 
1854, I made my original design for the 36-inch mortars since constructed by 
Government. That design, made and then dated by my own hand, lies now before 
the Academy.”f 
The mortar as designed (See Eig. 5, p. 227) was composed of a massive 
cast-iron base, containing a chamber of comparatively small capacity, 
hooped externally with wrought-iron, in one thickness of 9 or 10 ins., upon 
which rested a chase in three lengths, each of two thicknesses, tied down to 
the base by longitudinal bars. The resources of the day were unequal to the 
production of rings of such size and thickness, and the contractor actually 
contemplated at one time cutting them out of thick hammered plates. 
Happily for his reputation and the success of the mortars, this was not 
* See “Proceedings of'the Royal Irish Academy,” Yol. YII. p. 355. 
f “Proceedings, Royal Irish Academy,” Yol. YII. p. 334. The provisional specification of 
Blakely’s Patent, No. 431, of August 14, 1855, hears date February 27, 1855. His first pamphlet 
appeared in July of that year. Sir W, Armstrong’s provisional specification is dated February 11, 
1857; but Professor D. Treadwell, who submitted a plan for the construction of cannon to the 
British War Office in 1855, was so satisfied that the ground was then preoccupied, that in a letter 
dated May 28, 1855, addressed to the author, he says :—“After you mentioned to me at our inter* 
view last week, that the Government were already pursuing experiments upon the construction of 
cannon on a plan similar to that proposed by me, I abstained from occupying your time with many 
mechanical principles and details connected with it which would go far, I believe, to strengthen the 
design that I proposed, and amongst others those that form the subject of the accompanying 
paper .”—To Captain Tefroy, R.A. These dates, while confirming Mr. Mallet’s claim to priority, 
are important in any review of that epoch of mechanical activity, and are in no degree inconsistent 
with the claims of Professor Treadwell to the employment of coiled wrought-iron over steel barrels 
as early as 1842. These claims, after a full investigation by the American Academy of Arts and 
Sciences in 1865, were recognised by the award of that rare honor, the Rumford gold medal—the 
fourth only which that learned body had awarded in seventy years. 
