In prehistoric times the first man to make for himself a stone hatchet probably became the greatest warrior of his particular region. He may not have been as strong physically as his neighbor, but with the aid of so marvellous an invention as a stone hatchet he undoubtedly conquered his enemies and became a great prehistoric potentate, until some other great man made a larger and stronger hatchet; so down to the present invention has followed invention and improvement has been added to improvement to such an extent that it is difficult to imagine what new weapon of destruction man can develop in the future.

What would the past generation have said of a man who had prophesied great armies fighting in the air? Even in the early months of the war there were but few who realized what an important part of the war was to be carried on in the newly conquered element. When the infantry saw an occasional box-kite-looking machine drifting slowly over the lines, struggling to keep itself aloft, how many, I wonder, foresaw that in a few months these machines would be swooping down on them like swallows, raking them with machine guns by day and bombing them by night? How many artillery officers laughed at the suggestion that a day was coming when thousands of great guns would be directed from the air? Yet in a few short months two great blind fighting giants, their arms stretching from the Belgian coast to the Swiss border, learned to see each other; and their eyes were in the air.

The first aeroplanes to cross the lines carried no armament; they were for reconnaissance work only; they would fly a few miles back of the enemy lines, have a good look around, and then come back and report what they had seen. Often British and German machines would pass quite close to each other. Flying was considered sufficiently dangerous, not to add a further danger to it by attacking enemy machines.

The Germans, however, because they greatly outnumbered the British in the air, had more eyes to see with; something had to be done; so rifles were carried by the British and a finer sport than shooting ducks came into vogue. This quickly led to the carrying of machine guns. Ingenuity in devising sights to compensate for the speed of our own machines and to gauge a proper deflection according to the speed and angle of approach of the enemy machine, soon decreased the advantage the enemy aviators had through superior numbers.

For example, if our machine was flying at the rate of one hundred miles per hour and the enemy's machine was travelling past us in the opposite direction at an equal rate, our fore-sight nullified our motion and enabled us to shoot as if from a stationary base, while our back-sight helped us to gauge that imaginary point at which to shoot where our bullets and the enemy machine would meet. In other words, we shot at an enemy machine although we ourselves were travelling rapidly, exactly as a sportsman shoots at a bird on the wing.

Then a new aeroplane was developed, the single-seater tractor, with a Vickers gun, synchronized to shoot through the rapidly revolving propeller so as to avoid the blades. These machines were used to patrol the lines and keep enemy machines from crossing, or to accompany a reconnaissance machine as protector; for they were very much faster, easier to manoeuvre, and altogether very much more efficient fighters. At first they operated singly, but it was soon discovered that two of these scout machines operating together invariably obtained better success than when operating alone. This led to formation flying, and up to the cessation of hostilities these formations grew in size and varied in shape.

The reconnaissance work was soon divided into classes: long and short reconnaissance and photographic reconnaissance. The long reconnaissance dealt with enemy movements far behind the lines; the short reconnaissance with enemy activities near the front. The photographic reconnaissance consisted of taking aerial photographs of everything of military importance within flying radius. These photographs pieced together showed the enemy defences along the entire British front and their changes from day to day.

Wireless apparatus was soon attached to aeroplanes, and this enabled an aviator to communicate with people on the ground many miles away; and so what was called artillery observation was developed. Roughly speaking, this is the direction of the fire of our batteries against enemy targets; but, just as specialization came in reconnaissance and fighting, so now machines specialized in artillery observation. To-day the efficiency of the artillery depends largely upon its direction from the air. For instance, when a battery takes over a new area the gunners may be called upon to fire at certain targets, such as cross-roads or houses used as infantry headquarters or ammunition and stores dumps, at a moment's notice. Consequently, if these targets are registered by aeroplane, all the gunners have to do when called upon to open fire is to refer to their registration book which will give them the necessary angles to use on their sights, then, by allowing for the temperature of the day and the direction and velocity of the wind, their shooting is certain to be far more accurate than it would be if the target had not been previously registered. The registration of targets to-day without the use of areoplanes is very often impossible.

The registration of targets from the air, however, is not the most important part of this work. For instance, a machine will be flying over enemy territory; the observer will see the flash of an enemy gun and will pin-point its position on his map, which is marked off into large and small lettered and numbered squares. This operation enables him to send by wireless what is known as a zone call, giving the exact location of the enemy battery to all of our batteries within range. The enemy battery then has to move suddenly, if it is ever to move at all.

Barrages can also be controlled very efficiently from the air, so, considering the comparatively short time that aeroplanes have been used in this work and the wonderful results that have been obtained, it does not take much imagination to see the necessity for all future artillery officers to be trained as aviators.

In the earlier stages of the war it was very difficult for Headquarters to keep in close touch with the infantry during a "push"; consequently, considerable loss of life might result from one portion of the line advancing out of contact with another. Probably the eagerness of raw troops to keep on advancing regardless of their objective has led to a considerable and unnecessary loss of life. The aeroplane can be used in these situations to great advantage, and after the development of what is known as "contact patrol" the aeroplane became the connecting link between Headquarters and the infantry.

It was not until 1916 that the full powers of the aeroplane as an offensive weapon began to be realized. Bombing was done, but it was of a desultory nature, and although the number of machines engaged in this work steadily increased, and the work itself became more and more diversified and specialized, it was not until 1918 that the possibilities of the aeroplane as a purely offensive weapon were appreciated.

An aeroplane can operate far back of the enemy lines, both in the day and at night; enemy troops in transport can be bombed: railway stations, sidings, etc., damaged; transports of all kinds delayed; and ammunition dumps, when located, can be blown up. In fact, military targets of all sorts can be attacked from the air that cannot be reached in any other way. The very foundation of a nation's strength in war, its industry, can be attacked from the air and, if attacked on a large enough scale, can be destroyed. For instance, eighty per cent of the German steel industry was within bombing range of the Allies. The Westphalian group of high-grade steel industries centred at Essen is about two hundred miles from Nancy. If this group had been bombed on a large scale the source of supply of German guns and munitions could have been destroyed; for a blast furnace destroyed cannot be replaced within nine months, and the destruction of the central electrical plant of a steel factory would place the entire factory out of operation for at least six months. The hundreds of bombing machines which the English aeroplane factories were turning out at the time hostilities ceased, and the thousands of men being trained for bombing, make one wonder what would have happened to the German industries if the war had continued through the spring of 1919.

Besides these hundreds of aeroplanes under construction and the thousands of men in training, the Royal Air Force had in operation, November 11, 1918, over twenty thousand aeroplanes, over thirty thousand aviators, and over two hundred thousand mechanics and other personnel.