Behind the scenes at third U.S. army field headquaters. This teletype room in a trailertruck at Third U.S.

Behind the scenes at third U.S. army field headquaters. This teletype room in a trailertruck at Third U.S. Army field headquaters held six machines through which cryptic code messages could be transmitted to any part of the world. The teletypes were used only when the written word was necessary. The machine operations were arranged so that the wires could not be tapped without detection, all messages becoming garbled and the machines being thrown out of balance by such an attempt.