When the powder explodes, it blows out the bullets, which fly forward in a cone-shaped shower. A shrapnel shell contains 375 bullets, and when it has burst they travel fifty yards over a space about five yards wide and fifty yards long. As you may imagine, the bullets work great havoc on men and horses within this area. Sometimes the fuse does not explode the powder at the right time. In order that the shot may not be wasted, it is provided with a cap, which causes the shell to explode when it strikes the ground. A quick-firing gun, such as is used by the Royal Field Artillery, fires about six times a minute. When necessary it can fire much more rapidly than this. As many as twenty shots a minute have been fired from a British field gun.
You already know that the shells and cartridges are carried on wagons, each of which contains one hundred rounds. When a battery goes into action, each section has one of its wagons a few yards behind it. When all the shells and cartridges in that wagon are used, another wagon is brought up. When that is empty, the forty rounds carried in each gun limber are fired, and finally the two rounds in each gun carriage. After that, unless a fresh supply of ammunition is brought up, the gun is useless.
The 75 mm.[181] field gun used by the French is said to be the best in existence. It is a little over 8 feet 1 inch in length, fires a projectile weighing 15-2/3 pounds, and has a range of 7,110 yards. As each piece can fire twenty shots per minute, a perfect hail of shells can be kept up on an enemy's position.
It is a splendid sight to see a Royal Horse battery come into action. The teams advance at the gallop. At the signal "Halt! Section front," the gunners jump down from their seats on the gun carriages and limbers. Two of them lift the trail of the gun off the hook at the back of the limber, and two others man the wheels of the gun; the teams drive on with the limbers, the guns are spun round, and in three seconds are ready for firing.
Before the gun can do its work properly, the range—that is, the distance between the gun and the target—must be found. For this purpose trial shots are fired. The gunners guess the range, and then fire at a point some hundred yards less than the supposed distance. They watch for the puff of smoke which arises when the shell strikes the ground. If they see it in front of their target, they know that the range is short. Then another shell is fired one hundred yards beyond the supposed range. If this falls behind the target, they know that the range is too long. The next shot is fired at a distance midway between the short shot and the long shot, and thus the correct range is found. In order that the puffs of smoke may be distinctly seen, observers are sent forward to the right or left of the line of fire to watch where the shells fall. Sometimes they are provided with telescopic iron ladders, which they mount in order to have a better view. Field telephones are sometimes laid so that the observers can communicate with the batteries.
If an enemy has dug himself in and is firing from concealed trenches, aeroplanes are sent up to spy out the land. When the aviators discover a trench they drop down bits of tinsel, which glitter in the sunshine, or a bomb, which ignites when it strikes the ground, and sends up a cloud of smoke. The gunners then know where their target is. Sometimes the range is found by means of an instrument known as the range-finder. When firing begins the aviator watches the shots, and signals to the gunners until they are aiming correctly. The aeroplanes also discover the position of the enemy's artillery, so that it can be fired at. In order to deceive the airmen, the guns are covered with straw or boughs, so that they cannot be easily detected from above.
Another type of gun which is used in the field is called a howitzer. The great difference between the action of an ordinary gun and that of a howitzer is the difference between a boy throwing a stone at a mark which he can see and the same boy pitching a stone over a wall so that it will fall on something hidden from his view. The ordinary field gun has a long flat sweep of fire, and is therefore unable to shoot over hills, trees, or houses, or to drop shells on men lying close beside a bank or in a deep, narrow trench. Field guns can burst their shrapnel so that such men would not dare to look over the bank in front of their trenches and aim their rifles at the enemy, but they cannot actually hit the men in the trenches. In order to do this, the shots must be thrown high into the air, so that they will drop straight down on the trenches. Howitzers are used for this purpose. They are so made that the barrel can be tilted and the shots fired at a high angle.
