An excess of weight in the fore part of a gun is very injurious, by inducing and lengthening the tremulous vibration created by the explosion. The only necessity for strength forward in a cannon, arises from the necessity of resisting the lateral pressure from the condensation of the column of air in the tube. The pressure of the explosive gases is, by the velocity obtained before reaching the fore part, of very little amount, from the short period it is exerted on the interior. Therefore weight, in the fore part of a gun, be it ever so great, will not prevent recoil if there is not a proportionate quantity behind. It will retard or lessen the distance to which the recoil will drive the gun and carriage, but the evil is then over. If the slightest movement occurs in the gun, the shot is projected from an unsound base or foundation. It is precisely similar to a man who, in the act of throwing a stone, slips his foot backwards: the effect is at once apparent on the stone. If the trunnion of a gun breaks in the discharge, or a quoin flies out, the shot is materially affected; never ranging, under such circumstances, the accustomed distance, nor with its usual accuracy. Practice with mortars proves beyond dispute the necessity of a firm base for the gun, for with a much less charge they project a greater mass farther. A mortar discharged on land, exceeds in range the same description of gun on board of ship, or on the best-constructed platform. In truth, this is but another illustration of a law of nature: if you have not a solid fulcrum, it matters little what the power of your lever may be. Gunpowder is a powerful lever if exploded on a solid base; if not, its effects become limited in proportion. Unquestionably, much may yet be gained by an economical arrangement of our projectile force. Great and rapid as have been the acquisitions of knowledge in everything relating to gunnery in modern times, there still remains, I have no doubt, an unexplored mine of valuable treasure to be added to the science. It would effect a great improvement in the mortars used by the navy, destroying the tremendous vibration and shake given to the ship, increasing their efficiency and aiding the projecting power, to place them on beds of the softest lead, not less than twelve inches in thickness. Though this suggestion is only theoretical, experience would soon determine the least degree of substance available. Advantage would arise, in the first place, from the non-conducting tendency of the lead; in the second, from its density, and, of course, incompressibility. The one protecting the ship, the other being the most solid bed for the mortar that can by possibility be obtained.