Artillery of an Army Corps. The artillery of an army corps is under the command of a Colonel. It includes two groups of 75 mm. field guns, two groups of 105 (4 inch), or of 120 (5 inch), and one group of 155 (6 inch), quick-firing. This artillery is reinforced, in case of need, by the heavy artillery which the army can dispose of. The Colonel commanding the artillery assumes the command of all batteries, of whatever size, momentarily put at the disposal of his army corps. He is most specially intrusted with the selection of the ground on which to place the batteries, and it is he who has to specify the part each of them shall take in the action. The divisional batteries of the army corps are also under his command, at least during the preparation for the attacks. It is absolutely indispensable that each battery should be assigned its objective, and should be positively forbidden to scatter its projectiles promiscuously. Thus costly waste is avoided, and a definite purpose accomplished.
While getting ready for their first great attack in the Somme sector, the British, during an artillery preparation of several days’ duration that exceeded in intensity any previously known, fired a vast number of projectiles. At the time of the assault, the British infantry displayed an indomitable courage, and captured several important positions, but, for the want of a proper concentration of the fire of their artillery on the points to be destroyed, their heavy losses in men were too big a price to pay for the gains they made. The British artillery has since modified its methods, and, assisted by an unexcelled service of aviation, it has, over all its Front, impressed the Germans with the power and accuracy of its guns.
Artillery of a Division. At present, divisional artillery includes three groups of 75 mm. (each group composed of three batteries of four guns), one group of three batteries of four quick-firing 155 mm., and one battery of trench-guns, the number and size of which are variable. This artillery is under the command of a Colonel.
Further on we shall speak of the difficulty experienced in advancing the heavy guns through the country devastated by the Germans in March, 1917. The 75 mm. field artillery, only, was able to advance quickly enough. Guns of 105 mm. should have been able to follow the troops everywhere and give them help until the arrival of the heavier pieces.
In position, and at the time of active operations, the artillery of a division is reinforced by the artillery of the army corps and that of the army.
The longest range of field guns is 8500 metres.
The range of the howitzers varies between 10,000 and 14,000 metres.
Heavy guns have a much greater range. The 380 we shall soon be turning out will send a shell containing 150 kilograms of explosive to a distance of 38 kilometres.
Trench Artillery. This artillery includes special mortars, firing at a high angle projectiles containing powerful explosives; their longest range is not over two miles. They are principally used for the destruction of wire entanglements, first-line trenches, and dugouts. Their size varies from 58 to 340 mm.
The projectiles are provided with blades which maintain their direction through the air, as the guns firing them are not rifled. They are really aërial torpedoes, and are tremendously destructive to trenches and defences of every sort.