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By permission of Marconi's Wireless Telegraph Co., Ltd. 



THE ARRANGEMENT OF WIRELESS TELEPHONE AND WIRELESS TELEGRAPH APPARATUS IN AN AEROI'I.ANE 



The aerial wire is kept rolled up on a drum, and is paid out by the pilot when he wishes to send or receive a message. 



Speech can be transmitted from such apparatus for fifty miles or more. The electric current required is supplied by the 

 generator (see diagram), which is driven by the air rushing past the aeroplane. To obviate the terrific noise of the engine the 

 observer wears a helmet, and the telephone receivers fit over his ears in india-rubber cups. 



