in

Technology in WW1 (11)

Turkish troops use a heliograph at Huj, near aza City, in 1917. A heliograph is a wireless solar telegraph that signals by flashes of sunlight usually using Morse code, reflected by a mirror.

Photo Credit: National Archives / Library of Congress / Official German Photograph of WWI

What do you think?

Technology in WW1 (10)

Technology in WW1 (12)