Page:Wireless Telegraphy and Telephony (1908, Massey and Underhill).djvu/52

it was then called) was proposed before the principle of the real wireless telegraph was discovered, as the following retrospect will show.

Fig. 20.—Wireless Operator’s Desk, Signal Corps U. S. A.

19. Development of Wireless

Although Clerk-Maxwell proved the electromagnetic theory of light, mathematically, in 1864, it was not ex-