Subtitled "A Tell-You-How Story of Telephotography". The picture telegram was the predecessor to the fax. But the first transmitted photos go back to 1907, when Arthur Korn invented a machine that sent picture information over telegraph wires.
Years later, in 1924, AT&T invented a machine that would send the pictures over telephone wires, and the fax was born - only then they were called telephotographs. This silent film explains how the system worked, step by step:
"A photographic transparency was mounted on a spinning drum and scanned. This data, transformed into electrical signals that were proportional in intensity to the shades and tones of the image, were transmitted over phone lines and deposited onto a similarly spinning sheet of photographic negative film, which was then developed in a darkroom."
By 1935, the AP started a wire photo service. For years this was a specialized business mostly used by police and newspapers. But in 1966 Xerox created a 46-lb machine that could be used by businesses. The Japanese entered the market in the late 1970s, and for a while the fax became an essential part of business operations, now supplanted by computer-to-computer transmission of documents either via email or the web. But even as late as 2011, some businesses, like law firms, still rely on the fax machine.
Footage courtesy of AT&T Archives and History Center, Warren, NJ