THE ROYAL ARTILLERY INSTITUTION. 
237 
an elongated shot of the same weight striking with the same velocity into 
earth or masonry, will be as ^ to practically it is hardly worth while to 
encumber the question with these considerations, for which we have in¬ 
sufficient data ; so far as an inference may be drawn from a limited number 
of good penetrations observed in demolishing the two martello towers at 
Eastbourne* and Bexhill,t in 1860 : rifle shot certainly penetrate in a 
higher ratio than would be given by the rule—“ Directly as vis viva , inversely 
as the square of the diameterbut those rifle projectiles had a velocity 
more than double the velocities we are contemplating, and a proportionably 
more rapid spin. I think it is sufficient therefore to point out that the low 
velocity shells from rifled guns will doubtless on the above grounds, have an 
advantage over spherical projectiles; but to what extent can scarcely be 
stated in the absence of direct experiment. Their greater capacity for burst¬ 
ing powder is obvious, and greatly augments their relative effect. 
9. This superiority does not rest entirely on hypothesis. The Prussian 
Government two years ago took advantage of the demolition of the Portress of 
Julich or Juliers, to make certain experiments bearing upon the present 
enquiry on a large scale; unfortunately, while it duly occurred to the British 
Government that this was a very important military operation, and advantage 
was taken of the friendly permission of the Prussian authorities to send 
Engineer Officers to witness it; it seems to have been overlooked that it was 
equally an artillery experiment, and no British Artillery Officer was sent 
there. We have however a very full account published by Captain Weigelt, 
Commissioner from the Brandenberg Artillery, and which has been translated 
by Lieutenant de Cetto, R.H.A., from whose MS. I extract the following 
particulars :— 
Experiment 1 . —17th September, 1860. 
Two brass 12-prs. rifled, calibre 4*674 English inches, firing shells of 27 lbs. 
at 1072 yds., charge about 2*1 lbs., breached a brick wall 2 ft. 9 in. thick 
in 32 rounds (16 per gun), of which only 8 took effect. The profile of the 
work is shewn in Eig. 1. 
Pig. 1. 
The wall was 7 ft. high, and completely covered by a counterscarp 90 ft. 
distant; but of such trifling relief that the angle of descent did not neces¬ 
sarily exceed 5°; as two feet of the base of the wall were covered by the 
counterscarp of its own ditch, the space to be breached was reduced to 5 ft. 
in height. 
* Report of Breaching Experiments at Eastbourne. (Special Paper, Sept. 8, 1860). 
f Yide Yol. II. p.397. 
