The author asks a dispassionate perusal and careful study of his work, in justice to himself and to the importance of the subject. Judging of future probabilities by what has already been accomplished, the reader will be prepared for what follows. That great and important changes must take place in artillery cannot be doubted, and should England refuse to avail herself of the improvements to be effected, other nations, and amongst them our late opponent, will be the first to seize and adopt them. In former works I have asked the indulgence of my military readers on account of my scanty military knowledge; but professional men appear to be equally in the dark with the uninitiated: indeed, the lamentable shortcomings of the English artillerists have placed them in the rank of mere “waiters upon providence” for the next step towards improvement. The present time is decidedly propitious; let improvements now be made, and we may surely hope that they will be appreciated by the public, if not by the Government authorities. What is the best metal for cannon? is a question which has often been asked, and the answers have been very conflicting. Some have advocated mixtures of copper and tin; others have advocated cast iron, and more recently wrought iron; still more recently steel, and, lastly, cast steel, have had their advocates. Arguments as plentiful as summer flowers have been advanced in favour of each, and the argument has been carried on with a vast amount of prejudice and warmth, according to the degree of acquaintance with or attachment to the favourite metal of each individual. It is rare to meet with a mind free from bias, equally well acquainted with the merits of the several metals, and their application to the purposes intended. Still more rare is it to meet with a mind possessing all this metallurgic knowledge, and combining with it an intimate acquaintance with the principles of projectiles, as well as a scientific knowledge of the construction of the engine (the perfection of which consists in its having no points which are weak or unnecessarily strong); and yet it is by such a combination of knowledge and the application of these principles that we must be guided, if we would be successful in the accumulation of projectile power. In the present age we are really alive to the advantage of “playing at long bowls;” and the question now to be determined is, what is the greatest weight of shot and shell we can throw, and how many miles can we project it. The Americans were undoubtedly the first to discover the great advantage of this question with their lesser frigates; the late war has developed it still more; and it now remains to be ascertained how much further can we go. For on this important point the superior efficacy of artillery depends.