The Aeroplane in War

by Claude Grahame-White; Harry Harper

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.