796 



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 



