THE ROYAL ARTILLERY INSTITUTION. 
241 
It ought also to be considered with respect to probable penetration with 
the small charges necessarily used, but as the experiment has only been 
made on a wall of lightly rammed earth, it is difficult to calculate anything 
like an effect. It is a fair presumption, however, that the action of such 
powerful projectiles as 68-pr. shot, assisted by 10-in. shells filled with 
powder, would very possibly succeed in breaking down the brick wall in 
question. 
6. On the whole therefore it appears that 68-pr. carronades and 10-in. 
howitzers placed in battery at 400 yds., and fired with 15° of elevation, 
afford the greatest hopes of success, and by the preceding table there is 
just reason to expect, that from a continuance of fire without change, about 
halt the practice would be successful. 
It is in consequence submitted to His Grace the Master-General, whether 
these results do not merit a more definitive investigation of the experiment, 
by trying the fire against a real wall, disposed according to the profile of 
Carnot's system. 
(The draught is not signed , but is in the handwriting of the late Sir 
Alexander Dickson, R.A .) 
