As to the guns, the contributions of this superbly illustrated volume are of the very greatest value. Nothing in print equals it, except Mr. Holley's recent great treatise, some of whose tables are here also employed by permission. Here we find the most authentic statements, both as to the work done by the large rifled guns, and as to that trick of bursting which is their gravest weakness. But for this, the heavy ordnance of Parrott would be a magnificent success. And when we consider that six two-hundred pounders and seventeen one-hundred pounders were burst during the siege of Charleston, as recorded in this volume,--that five one-hundred pounders are said to have been burst in a single week on Morris Island at a later period, and that Admiral Porter reports six similar instances during the first attack on Fort Fisher,--it was certainly worth while in the publisher of this work, with his usual liberality, to devote a long series of admirable plates, prepared under the direction of Captain Mordecai, to the details of these dangerous fractures. It is generally admitted that the smaller "Parrott" guns, including the thirty pounders, approach very near perfection. The large calibres have precisely the same merits, as respects range, accuracy, and simplicity of construction and manipulation. This their work against Fort Sumter shows. But the deficiency of endurance belongs to the large guns alone; since the smaller, after an immense amount of service, have shown no sort of weakness. Yet, if the principle be correct, on which the latter are strengthened, there seems no reason why the same degree of endurance may not yet be secured for the larger. It is simply a mechanical problem, whose solution cannot be far off. The guns have burst both longitudinally and laterally, and in quite a variety of position and service. General Turner's suggestion, that an important secondary cause of bursting is the presence of sand within the bore, among the ever-blowing sand-hills of the Sea Islands, seems justified by the fact that in the naval service the accidents have been far less frequent,--a thing in all respects fortunate, by the way, as such explosions on board ship involve far greater sacrifice of life than on land. Another secondary cause is the premature explosion of shell within the bore, a defect which should be also remediable. Indeed, the "Parrott" shell were at first notoriously defective, often bursting too soon or not at all, and thus losing much of their usefulness; though this defect has now been, in a great degree, remedied. The discussion of the whole subject in this book seems reasonable and unprejudiced, and a letter from the maker of the guns, at the end, gives with equal candor his side of the question.