360 
when firing red-hot shot, &c., depends upon the very same principles of 
initial tension and compression, upon which the construction of ringed 
ordnance depends, and which were then clearly pointed out by me, and, 
with the aid of large diagrams, exhibited to the Academy. 
It is not necessary I should incumber further this already too long 
controversy, by making any observations upon what Captain Blakely 
writes referring to his quotation from section 288 (p. 152 of separate edi- 
tion) of my paper of 25th June, 1855, upon M. Thiery’s claims im this 
matter, further than to say that “‘the essential and radical distinction” 
referred to by me in the passage quoted, which must be read in connexion 
with the preceding section 287, is one between the effects of increased 
strength, due to construction in one extended and one compressed ring, 
and those of construction in several superimposed extended and com- 
pressed rings, which give still greater or even unlimited strength; but 
the very same principles are common to both, only carried out more 
fully in the latter. Captain Blakely uses the passage to make it appear 
to assert ‘an essential and radical distinction,” not between two methods, 
based upon the same common principle, not of degrees of strength ob- 
tained by more or less fully carrying out principles the same in both 
cases, but as if there were some distinction between the principle itself, 
which is identical in both. 
The object is, of course, to suggest that Thiery’s one ply of rings 
did not anticipate Captain Blakely’s self-alleged priority in propos- 
ing ‘‘one, or more than one.” There is nothing, however, to show 
that Captain Blakely saw any value in more than one upon any prin- 
ciple more recondite than mere increase of thickness, at the date of the 
specification of his patent, August, 1855, nor until after he had read my 
paper of 25th June, 1855, and Dr. Hart’s investigation printed in the 
notes to it. Nor does it touch the question of Thiery’s priority, whe- 
ther he failed in practice or not (of which, however, there is no proof 
whatever), no more than the bursting of Captain Blakely’s own guns 
touches the question of his own originality in respect to time. : 
Mr. Mallet exhibited stmultaneously and explained to the Academy, 
after reading this paper, his original sheets of designs for the 36-inch 
mortars in the several phases of their progressive improvement, in proof 
of the statements as to them, made in his paper of the 11th inst. 
The first (that reproduced in the Proceedings—see Plate, page 335), 
and dated October, 1854, shows the original crude design; the chase 
and chamber, each constructed in two superimposed rings, one extended 
and one compressed, that design having been made and exhibited to‘Cap- 
tain Boxer, General Portlock, and others, before he had ever had the 
- honour of Dr. Hart’s acquaintance, or ever heard ofCaptain Blakely. 
The second is the original contract design for these mortars, with 
the signature of Mr. Charles Mare, the contractor, upon it, showing the 
partial abandonment of the construction in plies, the chase being forged 
in a single thickness, but the compressed and extended construction of 
the chamber still continued. This was the design as being acted on at 
the period when Mr. Mallet first called upon Dr. Hart, im company 
