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everything that Captain Blakely’s specification of his patent of August, 
1855, does, even to the general similarity of the lithographs accom- 
panying each respectively, and to the preference of a cast-iron interior 
instead of one of wrought-iron, upon which Captain Blakely lays so much 
stress, though erroneously, as Whitworth, Armstrong, and every other 
practical engineer have proved. 
There have been three epochs in the use and knowledge of ringed 
structure in artillery: the earliest, which goes back to the ‘‘ bombards” 
and ‘‘serpentines” of the early part of the fifteenth century, was that 
of the use of external rings shrunk on with initial tension, but without 
any knowledge whatever of the theory, or of the value of their being in 
initial tension, and the staves or tube that they enveloped being in com- 
pression, the construction being one of manipulative necessity only, and 
not of choice. 
Thiéry (though not fully or completely) inaugurated the second 
epoch by showing publicly that, although the manipulative necessity 
was long past, it would be advantageous to return to the method, be- 
cause of the principle of increased strength that it contained. 
The third and last epoch was that in which I myself placed for the first 
time in a clear, descriptive light the general conditions and methodic prin- 
ciples of ringed construction, and in whick Dr. Hart investigated and 
developed mathematically the laws by which such conditions and me- 
thodie principles are governed; both of these tasks were also more or 
less completely performed independently by Captain Blakely; but, as I 
have proved in this paper, at periods posterior to myself and to Dr. Hart, 
respectively. 
Caprain BraxeLy made some remarks in reply (June 14, 1860), of 
which he has since supplied the following memorandum :— 
Mr. President,—If I rightly understand Mr. Mallet, he this evening 
bases his claim to priority over me, firstly, on his having laid a plan 
for constructing mortars before Government in December, 1854; and, 
secondly, on his having published the theory in a paper read to this 
Academy in June, 1855. He withdraws his statement, made here on 
the 14th ultimo, that he had a letter from Dr. Hart, discussing the 
whole question, and dated July, 1854, and tells us he meant to say, and 
believes he did say, 1855, not 1854. 
Now, Sir, I made proposals on the subject to Government in Sep- 
tember, 1854, and was so thoroughly convinced of the correctness of my 
views, and of the possibility of constructing very powerful cannon on the 
plan, that I went out immediately afterwards to Constantinople and 
Balaclava, and communicated with the Ambassador, the Commander- 
in-Chief of the fleet, and the officer commanding the artillery ; and had 
guns been then strengthened on the plan I suggested, I feel confident 
many thousands of lives would have been saved, and the siege of Sevas- 
topol much shortened. 
