EIGHTH SECTION WIRELESS TELEGRAPHY AND PHOTOGRAPHY AS AIDS TO AERIAL RECONNAISSANCE
I. First tests and successes with wireless telegraphy—Difficulty of equipping an aeroplane with transmitting plant.
In the descriptions of the uses of an aeroplane in war, which have been set forth in previous sections, nothing has been said concerning an adjunct which now promises to have an importance quite overwhelming upon future operations with aircraft.
This has reference to the use of wireless telegraphy. It was thought, at first, that any employment of this marvel of science, so far as aeroplanes were concerned, would be hopeless. The fact that the aeroplane is suspended, so to speak, in mid-air, with no earth communication, made the problem of equipping it with wireless particularly difficult.
But the value of a wireless message, from a flying machine, has always been recognised; and so most careful experiments have been made to devise an apparatus. In addition to the difficulty of transmitting messages from an aeroplane, there was the important question of weight to be considered. It was seen that any apparatus, made to be carried upon aircraft, must be extremely light; and, at the same time, it was essential that it should be of a small and convenient size, so that it could be stowed away somewhere in the proximity of the pilot’s seat.
It was in America, in August, 1910, that the first success was obtained. An aeroplane ascended with the necessary transmitting mechanism on board, and with a long aerial wire trailing behind it, weighted with lead, from which the wireless messages were radiated. The apparatus was crude, and unsatisfactory from many points of view, but actual signals were received, from the aeroplane, by a station on the ground.
Only the most simple messages were attempted, and the aeroplane flew round in fairly close proximity to the receiving station. As a matter of fact, the best results reported, in connection with this series of tests, was a message transmitted from the aeroplane when it was 500 feet high, and which reached the receiving station from a distance of about a mile.
This result was distinctly encouraging. It showed that wireless telegraphy, as applied to the aeroplane, was not impossible; and it had the effect, also, of stimulating interest in other countries, and of setting many clever brains to work.
It was in the following month (September, 1910) that a series of experiments were begun in England. Salisbury Plain was the flying ground chosen, and Mr Robert Loraine, a well-known actor who had become prominent as an airman, was the pilot of the machine with which the tests were made.
The aeroplane employed in the experiments was a Bristol biplane, fitted with a "Gnome" motor; and the designer of the wireless transmitting mechanism used was Mr Thome Baker, a well-known electrical expert. After a number of tests, he had produced a transmitter which only weighed about 14 lb., and which could be fixed, quite conveniently, behind the pilot’s seat.
Mr Baker was also able to abolish the long trailing wire behind the machine, which had been used in the American experiments. Such a wire, it was recognised, was a bad feature of any equipment. Apart from the obvious clumsiness of such a device, it offered a danger of becoming entangled with the rapidly-revolving propeller of the machine, and so causing an accident. Mr Thorne Baker obviated this difficulty, in his tests, by twining his aerial wire round the wooden supports between the main-planes of the machine.
Another long wire, the receiver, was stretched between posts on the ground; and then Mr Loraine ascended, and began to circle round and round the aerodrome. For transmitting purposes, he had a little key strapped to his knee, and operated it with his left hand—his right hand being engaged, of course, with the controlling lever of his machine.
Again, as in the American experiments, only the simplest messages were attempted. They were, however, quite distinctly heard. At first, the signals were not received over a distance of more than half a mile, but it was soon found possible to increase the distance between transmitter and receiver to approximately one mile. At this distance, the dots and dashes telegraphed were distinctly read by Mr Thorne Baker, who received them—as is the custom with wireless telegraphy—through telephone ear-pieces.
Following these tests, Mr Thorne Baker set himself the task of perfecting his apparatus; and a very interesting experiment was planned, in December, 1910, in connection with the De Forest cross-Channel aeroplane prize.
Lieutenant H. E. Watkins, one of the competitors, consented to take up a transmitting apparatus with him, on his cross-Channel flight, so that he might endeavour to keep in touch with a steam-tug, in which his friends intended to follow him from Folkestone to the French coast.
The transmitter which Mr Baker prepared for this experiment was more powerful than the one used in the Salisbury Plain tests, and some conclusive results were expected from this oversea flight. Unfortunately, however, Lieutenant Watkins was delayed by bad weather, and a series of trifling accidents, and so was unable to start upon the flight. The wireless test had, therefore, to be abandoned.
After this, it fell to the lot of America to make the next move of any interest. Lieutenant Beck, a young officer-airman engaged in military experiments with aeroplanes, took up a transmitter with him, and was able to send messages to a special receiving station, over a distance of quite two and a half miles. This, naturally, was regarded as distinct progress. The messages were clearly read; and there now seemed no difficulty, with better transmitting mechanism, in increasing the distance over which the signals were sent.
II. French triumphs with wireless telegraphy—Messages sent over a distance of thirty-five miles.
In the meantime, as may be imagined, France had not been lethargic in dealing with this subject. The French military authorities had, from the first, recognised that wireless telegraphy, if it could be applied reliably to the aeroplane, would greatly increase the utility of aircraft in time of war.
At several of the French military aerodromes, at the beginning of 1911, experiments were in progress, and clever civilian electricians were called into conference by the authorities. But only meagre news leaked out as to what was actually being done.
Before the end of January, 1911, however, definite results had been obtained. Mr Maurice Farman, a brother of Mr Henry Farman, who had built an excellent biplane for military use, ascended at the aerodrome at Buc, and sent a wireless message back to the flying ground, when he was passing over the countryside quite ten miles away.
This was a highly-important result, and promised to place the wireless outfit on a practical basis, so far as war purposes were concerned. Further tests were made at Buc, and the radius over which messages could be transmitted was soon increased from ten to fifteen miles.
At this juncture, the French military authorities took the matter in hand with renewed vigour, and the energies of the scientific staff were directed towards still further increasing the transmitting power of the apparatus installed.
An improved transmitting mechanism, weighing about 55 lb., was built and fitted to a biplane at the beginning of July, 1911; and Captain Brenot, a prominent French military airman, was given the task of thoroughly testing this device. He was able to do so with remarkable results.
While flying between St Cyr and Rambouillet, he succeeded in getting into touch with the wireless installation fixed upon the Eiffel Tower in Paris. The distance was one of at least thirty-five miles.
Captain Brenot did more, also, than transmit a mere series of dots and dashes. He spelt out a complete message while flying, and it was correctly received by an operator of the Eiffel Tower wireless station. This historic aerial message was as follows:—
"Captain Brenot, conducting experiments in aeroplane with wireless telegraphy, to the Minister of War.—Flying between St Cyr and Rambouillet. We beg to present our sincere regards. We are above the forest of Rambouillet, at a height of 1640 feet."
Nothing could have been more dramatic, in its way, than the receipt of this message in Paris from an aeroplane, fitted with wireless telegraphy, thirty miles away; it demonstrated, conclusively, that an aeroplane, when equipped in this way, was an absolutely-revolutionary weapon of warfare.
Since then, French tests with wireless have been steadily going ahead, and improvements have been made. The results obtained are now more certain; and it has been proved, beyond doubt, that the wireless message from an air-scout will play a very prominent part in future military operations.
III. Practical uses of wireless upon aeroplanes—England’s lack of effort.
How wireless telegraphy will aid the military airman may readily be seen. It will, in the first instance, be a remarkable time-saver. Instead of returning to Headquarters with a brief and urgent report, the observation officer in an aeroplane will be able to transmit it instantaneously, while still flying on his course. In the case of machines not equipped with a wireless installation, a reconnoitring flight will need to be followed by a return journey to the aeroplane camp. Then the airman’s message will have to be brought along to Headquarters. Thus there will be some delay, although this can, of course, be reduced to a minimum by sound organisation.
But the fitting of a wireless apparatus will obviate, at one stroke, all delay occasioned by a machine flying back from the district over which it is reconnoitring, by the descent at the military camp, and by the conveying of the news to Headquarters.
It is not likely, however, that every machine will be fitted with a wireless outfit. In an aerial reconnaissance under ordinary conditions—made, say, during the early morning or evening, to show the general disposition of an enemy at a specified time—it will be sufficient if the airmen return to their starting-point, and the news is brought to Headquarters in the ordinary way. There will not, in such cases, be sufficient urgency to justify the use of wireless messages.
But, under many circumstances which will arise during war, a machine which can flash back frequent messages, without losing the time of actually flying back with them, will be of almost inestimable value.
Let us take, for example, the position of a Commander-in-Chief who is in the act of delivering a heavy attack, and wishes to know, from moment to moment if possible, how the onslaught is being withstood, and if there is any tendency on the part of his enemy to retreat. In such a case a special aeroplane, fitted with wireless, would be dispatched, to fly in circles over the fighting area; and a portable receiving apparatus would be moved up close beside the point where the Commander-in-Chief had stationed himself. In this way, news could be received in the form of a constant stream of messages.
This is only one instance of the practical utility of wireless telegraphy from an aeroplane during wartime; many others, naturally, present themselves. In the course of a battle, the officer commanding aeroplanes should always have, ready for an emergency, one or two machines which are equipped with wireless. Thus, immediately any point arises regarding a movement of the enemy, upon which the Commander-in-Chief desires speedy enlightenment, a machine can be sent off without a moment’s delay; and the information, once obtained, can be flashed back by wireless a second or so after the observation officer has made his reconnaissance.
During a series of military experiments with wireless telegraphy, carried out in France during August and September, 1911, the possibility of directing the fire of artillery, by means of messages from an aeroplane, was investigated. Ascending from a fortified position, which was supposed to be besieged, aeroplanes, equipped with wireless installations, made circuits over the country, in the immediate neighbourhood, and sent back messages to their Headquarters, describing with complete accuracy the position of concealed batteries, which were assumed to be carrying out a bombardment.
Aided by this intelligence, the gunners of the besieged position would, in actual warfare, have been able to direct a telling fire upon their hidden enemy. It would be possible, also, in such circumstances, for the aeroplanist to remain aloft during the firing, and actually direct the gunners in their aim by means of wireless signals.
Taking into consideration such possibilities as these, an eminent French military expert has observed: "The aeroplane, without wireless telegraphy, is a sufficiently wonderful ’arm,’ altering all our preconceived notions concerning warlike operations. And now comes this new marvel. It is almost impossible to calculate what the effect of wireless signals from an aeroplane, during a battle, will be. This much is certain. The use of machines so equipped will play a revolutionary part in any action. Upon their skilful handling, of course, much will depend. Unless a Commander-in-Chief has accustomed himself to their use, during peace manœuvres, and unless the officers operating the transmitting mechanism, and those receiving the messages, are well-trained and thoroughly accustomed to their work, the best results are not likely to be obtained."
Naturally, in this connection, the question arises: what is England doing? The reply cannot be anything but disappointing. The privately-conducted experiments of Mr Thorne Baker, previously mentioned, represent practically all that has been done to perfect wireless telegraphy for aerial use.
So far as the authorities are concerned, civilian suggestions of co-operation, towards obtaining improved apparatus, have not been received in an encouraging spirit. From the small army airship, "The Beta," wireless trials have, it is true, been carried out once or twice; and some unambitious experiments with biplanes, at the Royal Aircraft Factory, were reported in April, 1912. But no practical outfit has been devised.
As a matter of fact, this question of the application of wireless telegraphy to aeroplanes provides a very striking illustration of the evils of our backward policy. Immediately there was an opportunity of using wireless successfully, the French military authorities were able to take advantage of the situation, and carry out adequate tests. This was because their organisation was what it should be, and because they had men and machines ready to be used in any experiments required.
Our backward position told against us inevitably, when this new adjunct to the aeroplane came along. We had insufficient machines, and not enough men. It was, as a matter of fact, more than sufficient for us to make anything like a show in ordinary flying work, without being required to go a stage further, and experiment with wireless.
Thus the lesson can be forced home. France has taken up this new aid to aerial reconnoitring—is perfecting herself in it, and accustoming her officers to its use. We have not begun to work with it yet. We are thus a definite stage behind, and shall remain so, unless a real effort is put forth to make up leeway.
By the time we have come to the stage of adopting a wireless installation upon aeroplanes, France may be busy with some new, and even more important, phase of flying.
As the military expert quoted above remarks, with perfect truth, it is essential that adequate and realistic tests should be carried out, with such an aid as wireless telegraphy, before any really effective use can be made of it.
IV. Photography from a war aeroplane—The use of special automatic cameras.
While dealing, in this section, with such an adjunct to reconnoitring as is afforded by wireless telegraphy, it is permissible, also, to refer to the use of photography in connection with aeroplanes.
Here, once more, it is necessary to turn to France for an illustration of recent work. Ascending from the Chalons military camp, quite recently, Lieutenant Blard, an army airman, succeeded in obtaining some excellent photographs of Rheims when flying at an altitude of 4000 feet. He used a special camera.
In America, also, practical attention has been devoted to this phase of military aeroplaning. An officer, when flying in a biplane, has succeeded in obtaining good photographs from as great an altitude as 6000 feet.
The utility of photography, as increasing the powers of the aeroplane in war-time, will be considerable. In an aerial survey of country, for instance, the camera will play an important part. A series of good photographs, when pieced together, will reveal the characteristics of land from the military point of view; and, in taking photographs of fortifications, the aeroplane with a camera will find another ready use.
It is now held that all scouting aeroplanes should be fitted with a camera, to be used, during reconnoitring, whenever a favourable opportunity arises.
In the first tests made with photography from an aeroplane, an ordinary camera was used, being held, by the passenger in the machine, in the best position possible to secure a photograph of whatever object it was desired to snapshot.
But this method was seen to be somewhat clumsy. In many machines, for example, it was not possible to obtain a picture, when taken in this fashion, of anything directly below. The business of changing plates, also, was found to be an awkward one.
So it was seen that there was need for something in the nature of the automatic camera, specially designed for military work. In Germany, where great interest has been evinced in aerial photography, a camera with a special telephoto lens, operating almost like a gun, has been devised for use in an aeroplane. This machine the observer holds to his shoulder, "aiming" it at the object which he wishes to photograph, and making the exposure by the pulling of a trigger.
In England, where private enterprise has outstripped any official action, Mr Thorne Baker has devised a very ingenious camera. This is suspended below the aeroplane, in such a position that it points directly downwards; and the whole operation of the camera is automatic.
The airman or observer puts the machine in action by pressing a button. This causes a photograph to be taken of whatever the aeroplane is passing over at the moment. Then, by means of another piece of automatic machinery, a plate is changed for a fresh exposure. Such a camera as this will, undoubtedly, prove of very considerable value as an adjunct to survey work with an aeroplane.
At the end of August, 1911, several military officers in France carried out special tests with aerial photography. They made flights over fortresses, for example, and secured excellent pictures. Tracts of country were also photographed, as were troops on the march.
The result is that photography has joined wireless telegraphy, in the
French air-corps, as a definite aid to aerial reconnoitring.
[Illustration: WAR MONOPLANES "VOL PLANE." In the above picture, a two-seated, military type Bristol monoplane is seen descending, with engine stopped and propeller motionless, from a reconnoitring flight. Pilot and passenger are plainly discernable.]