334 
principle upon which such increase of strength depends. Provisional 
specifications, being merely part of the machinery of the Patent Office, 
remain buried-in its archives for six months; the lodgment of the full 
specification is the date of first publication of any patented invention. 
Captain Blakely’s publication of this invention, therefore, through the inter- 
vention of his patent, dates from the 14th of August, 1855. He can 
claim otherwise an earlier date, however. In 1855 he published a 
pamphlet, in which the method of construction is described, and in which, 
for the first time, his mathematical investigation of the law of increased 
strength, due to it, appears. The preface to the first edition of this 
pamphlet is dated the 27th of June, 1855; it must, therefore, have been 
first circulated at a later date, and, upon inquiring personally at the 
publisher’s (Ridgeway, Piccadilly, London), I was informed that it was 
not issued before the end of July or beginning of August, 1855—in fact, 
not until within a few days before the date of the specification of his 
patent; and this is the earliest period at which, in any way whatsoever, 
he has ever hitherto attempted to show that he had published or commu- 
nicated either the method of construction, with a knowledge of its prin- 
ciples, or the mathematical investigation of it. All Captain Blakely’s other 
proceedings subsequent in date we may pass over as immaterial to the 
issue before us. 
The 9-pounder—the achievements of which have been so often refer- 
red to—was not brought to Woolwich, nor fired, until very late in the 
year 1855 and early in 1856, and hence has nothing to do with the 
matter before us. A previous gun, an 18-pounder, of cast-iron, hooped 
with wrought-iron rings, which appears to have been the very earliest 
produced by Captain Blakely, was burst on trial at Woolwich on the 25th 
of May, 1855,—as stated in his own pamphlet, on “A proposed new 
method of constructing cannon,” &c., p. 28, published in 1858 by Ridge- 
way, London. If we take the production of this gun to be equivalent to 
the first publication of the method of construction by initial tension by 
Captain Blakely, then his claim dates from the 25th of May, 1855, to the 
method of construction, and, as already stated, from July or August, 1855, 
for the mathematical investigation of its laws. 
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 (vol. i., p. 806, and note to p. 811) 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, 
T made my original design for the 86-inch mortars, since constructed. by 
Government. ‘That design, made and then dated by my own hand, les 
now before the Academy, as exhibited by me here on the 14th of May 
last. (See p. 335.) 
In December, 1854, that identical design was exhibited to the Ord- 
nance authorities at Woolwich, and to many other persons; amongst others, 
