345 
So much for priority of suggestions to the authorities. 
With respect to publication, the question is more intricate. We 
must first determine what is publication—telling thirty or forty persons 
of a discovery, or printing a description of it for the public. 
Mr. Mallet claims to have informed this Academy of the matter on the 
25th of June, 1855. Whether he did so or not, I will discuss presently. 
But, Sir, he acknowledges that one of my guns burst in May, 1855. 
Surely, before bursting, it must have been made; and before being made, 
its construction must have been explained to many! Such was the 
case. Not only did the manufacturers know of it, but they consulted 
some eminent men* on the practicability of my plan; and, acting on 
their advice, offered, early in 1855, to contract to supply the Govern- 
ment with 16-inch mortars, made in three layers of consecutive tubes. 
Mr. Mallet’s paper was printed for the public in June, 1856 ;. but what 
I printed the year before, for private circulation, was advertised for 
public sale immediately on the cessation of the war with Russia. 
On the question of priority of putting our theory into practice, Mr. 
Mallet has told us that his mortars were commenced after June, 1855, 
and that afterwards they were completed, on a different design, in 1857. 
I made five guns before he commenced his first. 
Having now proved that I forestalled Mr. Mallet, in suggestions to 
Government, in communicating my views to a number of persons, in 
printing them for public information, and in putting them into practice, 
I cannot be suspected of any personal motive in stating, as I did at our 
last meeting, and as I do again now, that I believe Mr. Mallet is not an 
independent discoverer of the principle of construction in question, but 
that he learned it from Dr. Hart. 
All who heard Dr. Hart’s lucid explanation of the matter on the 14th 
ultimo, must have been convinced that his memory on the point is accu- 
rate. Mr. Mallet, he told us, came to him for advice about a plan for con- 
structing mortars of very thick longitudinal-voussoirs, fitted together like 
the staves of a tub, and surrounded by a single ply of wrought-iron rings, 
greater strength than usual to be obtained by increasing the thickness of 
the voussoirs, thus removing the wrought-iron rings from the centre, and 
obtaining the advantage of leverage. Dr. Hart saw clearly how heavy 
such a mortar would be, and himself suggested the plan now universally 
used. ; 
Mr. Mallet has read to us one letter, in which Dr. Hart gave the same 
account. I will, with your permission, read an extract from another. It 
is from Dr. Hart to the Editor of ‘‘ The Mechanic’s Magazine,” and pub- 
lished in No. 1760 of that periodical (February 21, 1857) :—‘‘ My pro- 
posal, on which Mr. Mallet has acted,” are the words here used by Dr. 
Hart in speaking of the plan in question; and I implicitly believe that 
* Amongst others, Sir Charles Fox was consulted. He had made the discovery quite 
independently, and his advice was of great value. For him, therefore, I must persist in 
claiming priority of discovery over Dr. Hart and Mr. Mallet, as I did at our last meeting. 
