The defense of warships with iron armor caused an increase in the size, weight and cali bres of sea-coast and naval cannon, and the whole method of gun-construction was altered. Armstrong was the first in England to see the necessity of a change, and his method was im fully a foot of wrought-iron. This monster, ponderous as it is, is surpassed in two import ant respects by the 16.25-inch breech-loading gun. This celebrated weapon throws a pro pctile weighing two cwt. less than the 17 inch, but has a more powerful muzzle velocity proved by Whitworth, Fraser, Palliser, Blakely and others. Francis Krupp of Essen, Prussia, invented a new method which proved so suc cessful that it was introduced in Germany, Russia, Austria, Belgium and Spain. The body of the gun was fabricated from a solid ingot of low steel worked under heavy steel ham mers and was strengthened by three or more steel tubes shrunk upon the central tube of the gun, the last ring, or tube, inclosing the breech, being forged in one piece with the trunnions, without a weld. The rings had various lengths and the gun was diminished in thickness to ward the muzzle, not by tapering, but by being turned with concentric steps of diminished heights. Krupp made all his projectiles and gun-carriages of steel. In the United States, Rodman, Dahlgren and Parrott devoted them selves to the art of gun-construction. The Rodman gun was of cast-iron; it was cast hollow and cooled from the inside, the exterior being in the meantime kept from rapid cooling by fires built around the gun in the casting pit. The Dahlgren gun was of iron cast solid and cooled from the exterior, very thick at the breech up to the trunnions, then diminishing in thickness to the muzzle. The Parrott gun, like the Rodman, was of cast-iron, cast hollow, cooled from the inside and strengthened about the chamber by an exterior tube of wrought iron bars spirally coiled and shrunk on.
During the past 25 years the struggle be tweengun and armor has gone continuously forward. An examination of the products of the Midvale Steel Company, Bethlehem Steel Company and foreign ordnance corporations shows ever-increasing gun power, culminating in the English made, Italian-owned gun, hav ing a bore whose diameter is 17 inches. The actual weight of this gun is 104 tons and its projectile turns the scale at 2,000 pounds. The execution of this gun will he realized when it is remembered that the six-inch gun is capable of crashing a 100-pound projectile through and a penetrating power superior by a couple of inches. With an initial velocity of 23 miles per minute it is not surprising that this gun can send a projectile through three feet of solid wrought-iron like so much cardboard.
One of the teachings of the great Euro pean War was the indisputable necessity in the modern army of a numerous and heavy ar tillery. The question of type is complicated. Without excessive multiplication of calibres it was, nevertheless, necessary to have various types of heavy guns, because they all had defi nite functions. A review of the different cali bres employed by the Germans leads to the conclusion that the modern army should have: (1) Heavy corps artillery, composed of com paratively light pieces, from 2,000 to 3,000 kg. with limber, pulled like ordinary field artillery, by six horses and able to follow the infantry in all of its movements on any ground. The light 105 mm. howitzer, model 1898, and the heavy 150 mm. howitzer, model 1905, repre sent this type in the German Army. These howitzers fire a projectile weighing, respec tively, 15 and 40 kg. (2) Heavy army artil lery, including the heaviest guns, drawn by 10 or 12 horses, weighing in general from 4,000 to 6,000 kgs., and firing from take-down plat forms. In the German Army this artillery is composed of long 19 cm., 13 cm., and 15 cm. calibres, having a range between 14 and 18 kms., and also of the 21 cm. mortars, throw ing a shell of 110 kgs. to a distance of nine kms. (3) Heavy siege artillery, composed of the 28 cm., 30.5 cm. and 42 cm. mortars of great range and of naval guns, mounted on trucks. This formidable artillery naturally re quires motor traction.
Field Artillery.— The manner of placing artillery and its employment must be regulated by its relative importance, under given circum stances, with respect to the action of the other arms. In the defensive, the principal part is usually assigned to the artillery; and the posi tions taken up by the other arms will, therefore, be subordinate to those of this arm. Unless
the batteries are on points which are inaccessible to the enemy's cavalry and infantry, they must be placed under the protection of the other troops, and be outflanked by them. As in the defensive, we should be prepared to receive the enemy on every point; the batteries must be distributed along the entire front of the posi tion occupied, and on those points from which they can obtain a good sweep over the avenues of approach to it, the guns being masked, when the ground favors, from the enemy's view, until the proper moment arrives for opening their fire. The distance between the batteries should not be much over 600 paces, so that by their fire they may cover well the ground intervening between them and afford mutual support, the light guns being placed on the more salient points of the front, from their shorter range and greater facility of manoeuvring; the heavier guns on the more retired points. Guns of vari ous calibre should not be placed in the same battery. A sufficient interval should also be left between batteries of different calibre to prevent the enemy from judging, by the variations in the effect of the shot, of the weight of metal of the batteries. Those positions for batteries should be sought for from which a fire can be maintained until the enemy has approached even within good rifle-range of them. Where the wings of a position are weak, batteries of the heaviest calibre should be placed to secure them. A sufficient number of pieces — selecting for the object in view horse-artillery in prefer ence to any other—should be held in reserve for a moment of need; to be thrown upon any point where the enemy's progress threatens danger; or to be used in covering the retreat. The collection of a large number of pieces in a single battery is a dangerous arrangement, particularly at the outset of an engagement. The exposure of so many guns together might present a strong inducement to the enemy to make an effort to carry the battery; a feat the more likely to succeed, as it is difficult either to withdraw the guns or change their position promptly after their fire is opened; and one which, if successful, might entail a fatal disaster on the assailed, from the loss of so many pieces at once. In the outset of offensive movements, good positions should be selected for the heaviest pieces, from which they can maintain a strong fire on the enemy until the lighter pieces and the columns of attack are brought into action. These positions should be taken on the flanks of the ground occupied by the assailant, or on the centre if more favorable to the end to be attained. In all cases, wide intervals should be left between the heavy bat teries and the other troops, in order that the latter may not suffer from the return-fire which the assailed will probably open on the batteries. For the same reason, care should be taken not to place other troops behind a point occupied by a battery, where they would he exposed to the return-fire of the assailed. When this cannot be avoided the troops should be so placed as to be covered by any undulation of the ground, or else be deployed in line to lessen the effects of the shot. The artillery which moves with the columns of attack should be divided into several strong batteries, as the object in this case is to produce a decisive impression upon a few points of the enemy's line by bringing an overwhelming fire to bear upon these points. These batteries should keep near enough to the other troops to be in safety from any attempts of the assailed to capture them. Their usual positions will be on the flanks and near the heads of the columns of attack; the intervals betAreen the batteries being sufficient for the i free manoeuvres of the other troops in large bodies. The manoeuvres of these batteries should be made with promptitude, so that no time may be lost for the action of their fire. They should get rapidly over unfavorable ground to good positions for firing, and maintain these as long as possible; detaching, in such cases a few pieces to accompany the columns of attack In all the movements of the batteries great care should be taken not to place them so that they shall in the least impede the operations of the other troops.