The effect of lead will be easily understood when explained in the following way. If a 36 lb. shot have a velocity of 2,000 feet per second, the force is equal to the velocity multiplied by the weight, or 72,000 lbs. The whole of this force would strike a wall, and be left there, if communicated by soft lead; if by iron, at the same velocity, it would be minus the amount of force required to make it rebound to the great distance to which iron invariably returns. Though created by the elasticity of the iron itself, this must be deducted from the effect produced, and hence arises the great advantage the lead possesses. We are aware that iron driven with a slight velocity rebounds less; true, and less is its real effect; for under the very same circumstances would the great advantages of the lead predominate. It may be objected, that lead is too easily misshaped; “pure it is, but with alloys not so.” At low velocities it might, but the greater velocities diminish that chance, as it is a well known fact that all dense incompressible bodies are least affected by an extremely sharp motion. All our arrangements in warlike preparations, at present, involve great weight of projectile for fracturing, not perforating. During the siege of Ciudad Rodrigo, 2,159 rounds, of twenty-four and eighteen pounders, were requisite to form the small breach of thirty feet wide, and 6,478 rounds for the larger of 100 feet. At Badajos there was expended, to form three breaches of 40, 90, and 150 feet respectively, the enormous amount of 31,861 rounds of the same sized iron shot. We may be pardoned if we presume to say, one-half the number of lead shot would have done more, and done it better. If we bear in mind, that the whole round of experiments from which Hutton drew his deductions, were conducted with iron projectiles, the inconsistency of taking his data as the standard will be apparent. The dissimilitude of specific gravities being great, namely, 7,425 and 11,327--or one-third difference--it clearly shows, without any effort of the imagination, that the range must be in the same proportion, with the addition of greater momentum. For it will scarcely be denied, that a ball of gold or platina, from the same cause, will maintain a velocity longer, and consequently range further, than even lead. Hutton’s theory only establishes the principle, that the lighter the body projected, the sooner it is acted upon by atmospheric resistance, and a medium velocity induced. We cannot attribute his preferring iron to arise from an opinion of its penetrating to greater depths; for a man of his extensive knowledge and research could scarcely be guilty of such an error. But even in our enlightened times we are told that elephants cannot be killed with any projectile but steel: leaden balls cannot do it. I should like to try, and receive the _tusks_ in return.