Without entering into the history of artillery, it will be sufficient to state that the peculiar distinguishing excellence of modern improvements in cannon is the attainment of superior efficiency, accuracy, and mobility, with a decrease in weight of metal. A gun of any given size is now many times superior to one of the same size in use fifty or a hundred years ago. It is not so much in big guns that we excel our predecessors—for there are many specimens of old cannon of great dimensions; but by our advance in science we are able so to shape our guns and our projectiles that with less weight of material we can throw larger shot to a greater distance and with more accuracy. A long course of mathematical experiment and calculation has determined the exact pressure of a charge of powder at all points in the bore of a cannon during its combustion and evolution into gas. These experiments have proved that strength is principally required near the breech, and that a cannon need not be of so great length as was formerly supposed to be necessary. We are thus able to construct guns which can be handled, throwing balls of several hundred pounds' weight. Another splendid result of scientific investigation is the method adopted for casting such monster guns. In order that the mass of metal may be of uniform tenacity and character, it should cool equably. This has been secured by a plan for introducing a stream of water through the core of the casting, so that the metal cools both within and without simultaneously.
About the time that the Italian war commenced, the subject of rifled cannon excited much popular interest. Exaggerated expectations were formed of the changes to be produced by them in the art of warfare. Many saw in them the means of abolishing war entirely. Of what use is it, they said, to array armies against each other, if they can be destroyed at two or three miles' distance? At the commencement of our own contest there was an undue partiality for rifled ordnance. Almost every commander of a battery desired to have rifled guns. The more correct views of the thoroughly accomplished artillery officers to whom was confided the arrangement of this branch of the service, and actual experience, have dissipated the unfounded estimate of their utility for field service, and established the proper proportions in an artillery force which they should compose. It has been ascertained that fighting will never be confined to long ranges—that guns which can throw large volumes of spherical case and canister into lines only a few hundred yards distant are as necessary as ever.
The necessity for rifled cannon arose from the perfection of rifled muskets. When these arms reached such a degree of excellence that horses and gunners could be shot down at a distance of one thousand yards, the old-fashioned smooth-bore artillery was deprived of its prestige. To retrieve this disadvantage and restore the superiority of artillery over musketry in length of range, methods of rifling cannon for field service became an important study. For assailing distant lines of troops, for opening a battle, for dispersing bodies of cavalry, for shelling intrenchments, for firing over troops from hills in their rear, rifled guns are of invaluable service. But, notwithstanding troops are now universally armed with muskets of long range, no battle of importance is fought without close engagements of the lines. The alternate advances and retreats of the infantry, firing at distances of less than one hundred yards, charging with fixed bayonets and frantic shouts, will always characterize any battle fought with vigor and enthusiasm. In such conflicts, wide-mouthed smooth bores, belching their torrents of iron, must play a conspicuous part.
Another fact, which will perhaps surprise the general reader, is that the form and character of projectiles have been matters of as much difficulty, have received as much investigation, and are of as much importance, as the shape and character of the guns. In fact, rifled pieces would be comparatively ineffective except projectiles adapted to them had been invented. It was necessary that projectiles of greater weight, of less resistance to the atmosphere, and of more accuracy of flight, than the old round shot, should be introduced. To accomplish these ends several things were necessary: 1st, the projectiles should be elongated; 2d, they should have conical points; 3d, the centre of gravity should be at a proper distance in front of the centre; 4th, there should be methods of steering them so that they should always go point foremost through the whole curve of their flight; 5th, they should fit the gun so as to take the rifles, yet not so closely as to strain it. To attain these and other requisites, innumerable plans have been devised. The projectile offering the best normal conditions is the arrow; it has length, a sharp point, centre of gravity near the head, and feathers for guiding it (sometimes so arranged that it shall rotate like a rifled ball). Improved projectiles, therefore, both for muskets and cannon, correspond in these essentials to the first products of man in the savage state.
We cannot, in this article, further discuss either such general principles or those of a more abstruse character, in their application to artillery, but will briefly state a few facts relative to its employment—confining ourselves exclusively to the field service.
The guns now principally used for battles, in the Northern armies, are 10 and 12-pounder Parrotts, three-inch United States rifles, and light 12-pounder smooth bores. The distinguishing characteristic of the Parrott guns is lightness of construction, secured by strengthening the breech (in accordance with the principles mentioned a few paragraphs back) with a band of wrought iron. This has been applied to guns of all sizes, and its excellence has been tested by General Gillmore in the reduction of Forts Pulaski and Sumter. The three-inch guns are made of wrought iron, are of light weight, but exceedingly tenacious and accurate. The 12-pounders, sometimes called Napoleons, are of bronze, with large caliber, and used chiefly for throwing shell and canister at comparatively short distances.
The greatest artillery conflict of the war (in the field) occurred at Gettysburg. For two hours in the afternoon of the memorable third day's battle, about four hundred cannon were filling the heavens with their thunder, and sending their volleys of death crashing in all directions.
It was estimated that the discharges numbered five or six a second; in fact, the ear could hardly detect any cessations in the roar. The air was constantly howling as the shells swept through it, while the falling of branches, cut from the trees by the furious missiles, seemed as if a tornado was in the height of its fury: every few minutes, a thunder heard above all other sounds, denoted the explosion of a caisson, sweeping into destruction, with a cataract of fire and iron, men and animals for hundreds of feet around it. The effect of such a fire of artillery is, however, much less deadly than any except those who have been subject to it can believe. The prevalent impression concerning the relative destructiveness of cannon and musketry is another instance of popular error. In the first place, all firing at over a mile distance contains a large proportion of the elements of chance, for it is impossible to get the range and to time the fuses so accurately as to make any considerable percentage of the shots effective; and in the next place, except when marching to a close conflict, the men are generally protected by lying down behind inequalities of the ground, or other accidental or designed defences. The proportion killed in any battle by artillery fire is very small. Lines of men frequently lie exposed to constant shelling for hours, with small loss; in fact, in such cases, old soldiers will eat their rations, or smoke their pipes, or perhaps have a game of poker, with great equanimity.
No portion of the military service has been more misrepresented than the medical department. An opinion seems to prevail quite extensively that the army surgeon is generally a young graduate, vain of his official position, who cares little for the health of the soldier, and glories in the opportunities afforded by a battle for reckless operations. Such an opinion is altogether fallacious. In the regiments there are undoubtedly many physicians who have adopted the service as a resource for a living which they were unable to find at home, but the majority are exactly the same class of professional men as those who pursue useful and honorable careers in all our cities and villages. When a physician is called upon at home, it happens in a majority of cases—as every honest member of the profession will admit—that there is little or no necessity for his services. Too sagacious to avow this, he gravely makes some simple prescription, and as gravely pockets his fee. In camp, however, the potent argument of the fee does not prevail, and men who run to the doctor with trifling ailments, by which they hope to be relieved from duty, receive a rebuff instead of a pill. They instantly write letters complaining of his inhumanity. In regard to operations, it is a frequent remark by the most experienced surgeons that lives are lost from the