Page:Popular Science Monthly Volume 90.djvu/812

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��Popular Science Monthly

��the Somme by endless instances of dis- tinguished services rendered. In spite of his obscurity, he has won many decorations.

But that his service is still far from perfect, however effective it has proved, was still evident when I left France less than a year ago. I do not intend to be technical in my explanations in this article, but, in order to make clear the experiment- ing that has been done in wireless in this war, it is necessary for me to go back to the beginning. My aim is to give a short history of the wireless in France — its de- velopment in brief outline.

At the very outset of hostilities, before the trench warfare had begun and the armies had settled down to their present deadlock, the wireless was necessarily of a different character from that used now.

Then a motor lorry set — a ij^ K. W. Marconi set — was supplied to the Signal Branch of the Royal Engineers. All through the retreat from Mons and during the fight on the Marne, this set was used and did excellent work.

But with the end of the moving fighting and the beginning of trench monotony, the lorry set lost its value. Soon it was entirely supplanted by the systematic working of trench telephones, and for a while the wire- less went almost completely out of use.

But not for long. The ineffectiveness of trench telephones under certain conditions was soon very painfully apparent. When actual fighting was in progress, they failed more than once at critical moments. Some- times a shell would break down the com- munications; or an artillery battery would carry off the air line poles; or an enter- prising Tommy, on his way through a com- munication trench, would cut off a length of cable to make a shoe lace.

Even commanding officers who were al- ways sceptical on the subject of wireless in the trenches, were forced to confess that their old friend, the telephone, was not always reliable in case of a crisis. So, on their recommendation, it was decided to undertake some experiments which would perfect the wireless for warfare.

It was now decided that the requirements of the new fighting called for a portable set for the first line trenches, and a group of officers who had already distinguished themselves in various capacities, were de- tailed to take charge of the work and evolve an instrument for the purpose.

They introduced a small, simple set con- sisting of a I -in. spark coil, Leyden jar

��condenser (3) and an aerial coil. Receiving, a single inductance, silicon detector, vari- able capacity 'phone condenser and 'phones 1000 ohms. The aerial was supported on two 8-ft. bamboo poles, 80 ft. apart with a single wire. The ground consisted of a wire gauze mat 8 by 3 ft. With this set it was discovered that fairly loud signals could be heard from three to five miles.

When the instrument, however, was put to its first real test at L , it rose magnifi- cently to the demands of the situation, acting to its full range of five miles.

For a long time this set was used with excellent and unvarying results. In regard to the transmission of messages it lacked nothing. But it had just one drawback — a minor one but occasionally important. Being placed loosely on a board, it was clumsy to carry, a fact which often hindered the work by causing loss of time.

Once more the officers set to work. It

was a Captain L who found the means

of combating the difficulty. He discarded the board, and substituted a box 18 by 9 by 9 in. in which he placed the set. This was carried on the back and proved to be a most compact and convenient instrument.,

I remember when the first experiments were made with this set, some distance behind the line. They took the form of contests between the wireless and tele- phone. A detachment from each would start off from a trench, as if during an actual engagement, to a position some 500 yd. distant. Then each would do his ut- most to establish communications as quicjc- ly as possible.

From the very first the wireless man won by an average of some thirty seconds, no small consideration in warfare, when per- haps it is a question of holding ground already gained.

The instrument being now perfected, the next question was the training of the men. In England depots were at once established, and young fellows already equipped with a working knowledge of the job, such as Post Office Telegraphers and the like, were en- rolled in the wireless section.

Similar schools were established in France behind the lines at each of the Army Head- quarters, and the officers in charge would occasionally go into the trenches and pick out a few of the most intelligent infantry men with a view to training them as operators. No Tommy but tried his hard- est to be picked. He looked on the training as a good opportunity to rest, a nice break

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