Why, it took the old-time soldier the best part of a minute to load his gun and prepare it for firing! And he would tell you that his "Brown Bess" or flint-lock musket was a very great improvement on the hand-guns used in earlier times. He might tell you of one battle in which the soldiers, armed with the old match-lock musket, only succeeded in firing seven volleys during a battle lasting eight hours. Wellington's soldier would no doubt be very proud of his "Brown Bess." To speak of a gun that would be able to fire even 10 shots per minute might seem to him to be going much too far. To speak of 100 shots per minute would seem ridiculous, but the idea of any gun ever being able to fire 1000 shots per minute would be quite unthinkable. He would tell you that such things might happen in fairy tales, but certainly never in real life. It would take you many minutes to count 1000. Even if you were to say "one—one—one" a thousand times it would take you about five minutes. That being so, how could it ever be possible for a man to load and reload a gun one thousand times in a minute.

We quite sympathise with this imaginary old-time soldier whose best weapon was a flint-lock musket. He had not seen any of the mechanical appliances which you and I have seen. If he had happened to be well posted in the history of guns, which was not at all likely, he could have told you that someone had tried, long before his time, to make a gun that would fire one shot immediately after another, and that it was no good at all.

This early idea was to fix a number of guns on one stand or mounting so that the guns might be fired in rapid succession. It was really a "battery" of hand-guns made into one machine. The action of this early machine-gun was very poor; indeed there was no use of attempting to make a machine-gun in these days, because they had no satisfactory means of loading such a gun with the explosive. And so our old-time soldier would have been quite justified in saying the attempt to make a machine-gun had been an entire failure.

But the French, later on, made a machine-gun: what they called a "mitrailleuse." They invented this at the time of the Franco-Prussian War (1870), in which, you will remember, Louis Napoleon, nephew of the first Emperor, was beaten by the Germans. Terrible tales were told of what this machine-gun would be able to do, but it did not enable Napoleon III. to win the war; indeed, the gun was not a great success.

Some years earlier an American had invented another machine-gun. The American's name was Gatling, and you have heard, no doubt, of the Gatling gun. If you had seen the original gun at some distance you would have thought it was a large cannon, but when you got nearer to it you would have noticed that instead of one large barrel there were ten small barrels combined together in a bundle, as it were. Four men looked after each gun, although only two of them took part in the actual firing. One of these two men looked after the supply of cartridges, while the other turned a handle as though he were playing a barrel-organ. In reality the turning of the handle worked the mechanism, which brought each of the ten barrels in turn into the firing position.

These machine-guns which were invented by Dr Gatling were used in the American Civil War (1862), and they have been greatly improved since that time. However, they have been replaced now by the Maxim gun, the French mitrailleuse, and other types of machine-guns.

The one machine-gun which will be of most interest to you is the Maxim gun, because it is largely used by our own soldiers and sailors. This gun was invented by Sir Hiram Maxim in 1884, and it is a terrible weapon for the enemy to face. During the Great War we read continually of how these guns mowed down the enemy. The effect of the torrent of bullets was similar to that of a scythe cutting down grass. The sacrifice of human life in a modern war is too terrible to think of, and we can only hope that wars will be made impossible in the future.

This Maxim gun is a very clever invention; we wish to see how it works. If we had happened to meet the inventor at the time he was experimenting with this gun he would have pointed out to us that the great advantage of his gun was that its action is entirely automatic. In the Gatling and other machine-guns the soldier had to keep turning a handle in order to fire each shot in succession, whereas the Maxim gun works all its mechanism on its own account. To turn the handle of the Gatling gun required the expenditure of some energy on the part of the soldier, and it goes without saying that the Maxim gun will require a supply of energy to turn its mechanism. Where does it get this energy?

When the gunpowder is exploded in a gun it not only forces the bullet along the barrel, but it also gives the gun itself a push backwards. This is called the recoil of the gun, or you might describe it as the back kick of the gun. I remember hearing the following story when I was probably about your age. It told of an Irishman who went out to shoot sparrows and frighten them away from the fields in which seed had been sown. This Irishman had no experience in shooting, and the weapon he took with him was a very old-fashioned one, which happened to have a very energetic recoil or back kick. Taking good aim at one of the guilty sparrows, the Irishman pulled the trigger, when bang went the gun and off hopped the sparrow, chirping till it was clear of the danger zone. This was a surprise to Pat, whose shoulder now ached with the kick of the gun, and he shouted to the sparrow: "Begorrah! if you had been at this end of the gun you would not have been so chirpy." It was this natural recoil of the gun that Sir Hiram Maxim caused to work the machine-gun. Of course the first shot has to be fired by pulling the trigger, then the back kick fires the next shot, and the back kick of that shot fires the next one, and so on and on this goes so long as the gun is supplied with cartridges to fire.

The work that has to be done by this back kick is not merely the equivalent of pulling the trigger. It has to do all that the individual soldier does. It has to load the cartridge into the barrel of the gun, pull back the trigger, fire it, extricate the empty cartridge and throw it out, then bring forward a new cartridge, load it and repeat these movements hundreds of times in a minute.

We are not going to worry about the detail of the Maxim, but just to notice that the barrel of the gun is arranged to slide back within an outer casing. When the recoil forces the barrel back, it extends a strong spring which not only pulls the barrel back into the casing but at the same time operates the necessary mechanism to load, fire and unload the gun. The outer casing has double walls, and between the walls is water to help to keep the gun cool. The cartridges for a machine-gun are placed in a long band or belt, which carries them into the gun. Each belt holds 250 cartridges, and additional belts can be made to follow one another in rapid succession. The cartridges are arranged like a regiment of soldiers marching in single file. Suppose we are watching the inventor giving a demonstration with his gun, and we ask him how many shots his gun fires in a minute. He tells us that it usually fires from 400 to 600 shots per minute, but you say that Dr Gatling's gun can fire 1000 shots per minute. Sir Hiram Maxim would then explain that his gun could also fire 1000 shots per minute, but he prefers it to go slower, as the gun can then be kept cooler. Besides, even 400 shots per minute is fast enough.

The inventor points out to us that the advantage in his gun being entirely automatic is not only that it saves the soldier turning a handle to fire the gun, but it leaves the soldier quite free to aim on the approaching enemy. We shall suppose that the inventor is shooting at a target, and in order to show us how very easily the gun is moved, while it is being fired, he traces his own name with bullet marks on the target. What a difference between this machine-gun and the old match-lock musket!

Picture an old-time soldier preparing to fire upon an approaching enemy. He takes his powder horn and pours some gunpowder down the muzzle of his gun. He then inserts a wad and a round bullet, and pushes these down until they rest against the gunpowder. He then endeavours to light the end of his slow match, but it is not easy, in the excitement of the moment, to get the flint and steel to produce sufficient sparks to set the match alight. At last the match is ready, but the wind has blown the gunpowder from the touch-hole, and when the trigger is pulled the gun does not go off.

Picture our soldiers of to-day with the Maxim gun. They have their guns in position in the trenches, as an attack by the enemy is expected. When a telephone message warns the soldiers that the enemy are about to charge the trench the gunner simply presses a lever, which fires the first shot, then, watching the approaching enemy, he keeps the gun right on them, and we read later that the enemy attacked us at a certain point and that they were mown down by the fire of the machine-guns and the attack failed; the enemy were repulsed.

These Maxim guns are used both by our soldiers and sailors. The guns can be very conveniently mounted in any position. In the Great War we even mounted machine-guns in the side cars attached to motorcycles, so that they could be hurried into action at any required point.

Another gun which came into prominence in the Great War was the Lewis machine-gun, which was the invention of an American. In this gun the force which operates the mechanism is obtained from the pressure of the gases of explosion instead of from the recoil of the gun. Instead of a long belt of cartridges there is a rotating drum magazine which holds fifty cartridges. These can be discharged by the gun in four seconds, and a fresh magazine can be put in position in two seconds.

Those of us who were out of the nursery before you were born can remember that there was a gun called a pom-pom, which was used in the South African War. It was not unlike an overgrown Maxim gun, but it fired explosive shells instead of solid bullets. We shall have a talk about shells later on, when we come to consider what an explosive is. Meantime we wish to have a look at some of the giant guns of to-day.