The difficulty in using this shell is to prevent its explosion when the gun is discharged; and to obviate this all our engineering skill is required. Time and experience will show that, by a modification of the propelling agent, the shell may be started from a rifled cannon at a very low velocity; the velocity being increased like that of the rocket. This is to be done by modifying the arrangement of the gunpowder so as to ensure the shell acquiring its greatest velocity as it leaves the muzzle of the cannon. The result of this has been already shown. On the shell striking any object, such as the ship’s side, the metal of the shell is driven in upon itself, and an explosion of the fulminate follows as a natural consequence. Experiment has proved that shells exploding as they strike the ship’s sides, produce very little damage beyond making a hole in the ship the size of the shell. This, no doubt, arises from the short space of time occupied by the shell in passing through the side of the ship; all its force being exerted in the interior instead of on the sides of the vessel. All shells of the nature alluded to would, at certain distances, take such a line of flight as to ensure them dipping towards the centre of gravity, and thus exploding the magazines, however deep below the water-line; and when we consider the destructive effects of fulminates, we think it quite within the range of probability that they might produce all the effects we have spoken of. There are many agents equally powerful to be introduced into destructive warfare; and with the advantages to be derived from improvements in rifled shells, which the ingenuity of the present race will certainly effect, he would be a rash man who would set any limits to the advancement of projectile science. The great difficulty in the use of fulminates will be surmounted if these suggestions can be carried out; and experiment is all that will then be necessary to establish the line of proceeding. To effect this is the province of the Government of the country; to wait for it to be perfected by individual skill and enterprise would be unjust to science, and injurious to the best interests of the nation. The needful expenditure can only be borne by the nation, and should be entered upon, in order to effect improvement in projectiles, with the view of maintaining our land and marine artillery at the highest point of efficiency.