many instances to a considerable percentage of the whole distance it had been projected. The greater the velocity with which an iron ball is projected the greater the rebound back from a hard substance such as stone. Reversely, the greater the velocity of lead, the greater its effect on the object struck. Walls or fortifications struck by leaden balls at the same velocities (waiving the advantage to lead by its greater specific gravity) would be pounded into sand by less than two-thirds the same number of lead as of iron shot. Any unprejudiced person may soon satisfy himself of this, by trying it with a musket or fowling piece. A leaden ball will pound itself a hole many times its own bulk, while an iron ball will not make a hole half its size. I have tried many experiments to ascertain the penetrating powers of iron and lead relatively, by striking various objects, from a boiler plate of half an inch thickness down to fir deals. The same size of lead will, under certain circumstances, punch a perfect hole in a plate of half-inch thickness, as I shall have occasion to show; while, under precisely the same arrangement, the iron ball would rebound back with very little diminution of force; and if the plate of iron be at a perfect right angle, the iron ball would nearly return into the muzzle, of the gun. In truth, I had a narrow escape seventeen years ago, from a bullet actually cutting the rim of my hat: so that it will be well, when experimenting in this way, to be sure that the person is well esconced, for fear of unpleasant results. Lead, therefore, for destroying ships, as well as stone walls, is unquestionably highly advantageous; even if projected with the same velocities as at present adopted for iron. The additional weight would not decrease the destructive effects; it would augment them. I perfectly agree with the American _privateer_, that the wonderfully destructive power of leaden cannon balls will create surprise, whenever they shall come generally into use. Imagine the effect from a gun of the dimensions of a 10-inch bore. It is dreadful to contemplate.