Wigwag

The immediate impetus for the Signal Corps was a decidedly low-tech flag system devised by Myer while he was serving as an Army surgeon and based on his medical dissertation, "A New Sign Language for Deaf Mutes." (Myer also had experience as a telegraph operator.) Known officially as the General Service Code, Myer's military signaling system is more familiarly referred to as "wigwag."

Wigwag was a simple, almost binary, code: wave the signal flag to the left to represent "one" or wave it to the right to represent "two." Letters of the alphabet were then constructed from combinations of one and two. For instance, A was 22, B was 2112, and C was 121.

(For a much more thorough look at the 150 years of the Signal Corps, see "Getting the Message Through: A Branch History of the U.S. Army Signal Corps," by Rebecca Robbins Raines, from which much of the information here was derived.)