Maj. Albert Myer

Wig Wag: The Army's "talking flags"
A signal system using flags and torches was invented by a U.S. Army surgeon, Major Albert Myer, in the 1850's and adopted by the U.S. Army in 1860. Myer's system permitted messages to be sent across areas where telegraph wires were unavailable. To the untrained observer, the flagman appeared to be merely waving a flag back and forth, hence the name "wig wag." Myer became the U.S. Army's first chief signal officer. Myer's assistant during the development of the wig wag system was an exceptional young officer named Lt. E. Porter Alexander. Alexander was a Georgian who resigned his commission in the U.S. Army to fight for the Confederates. He helped organize, equip, and train the Confederate Signal Service. Thus both armies used essentially the same signal system, so encoding messages became critical.

Cipher Disk

Codes and Ciphers
Two forms of code were used: initially a four-element code and later, a two-element code. In the four-element code, movements of the flag conveyed the numerals 1, 2, 3, or 4 which were grouped to stand for letters and sometimes words or phrases. The letter "B" might be "1423," for example. By the end of the war, a two-element code was in use. Letters were formed using just the numerals 1 and 2, as dots and dashes were used in telegraphy. A "1" was indicated by moving the flag from the vertical to the sender's left: a "2" indicated by waving to the sender's right. So "A" might be "12" or "X" sent as "1221." The motion of the flag was an integral aspect of the wig wig system enhancing readability of the signal. 

To encrypt the message, a signal disk made of two disks of brass or cardboard was used. One contained the alphabet, the other numeral combinations. By rotating the disk and changing the alignment of the numbers and letters, the codes could be easily changed.

Sending a message with signal flags

Flags, Torches and Telescopes
Signal parties used different combinations of flag size, color, and staff length to increase the readability of the signal. Signal kits issued by the U.S. Army included seven different flags in three different sizes--2'x2', 4'x4', and 6'x6'. The 2-foot flag, permitted sending a signal over short distances in tactical situations where the flagman had to lie down or signal from cover. The 4-foot flag was the most commonly used. The 6-foot flag was employed for extra long distances. Color combinations were, red or black with a white center square and white with a red center square. In any given situation the color selected was that which gave the best contrast to the background. The flag staff was made of hickory in 4-foot sections.

Myer's Manual of Signals stated that with a 12-foot staff and 4-foot flag, signals "are easily read at a distance of 8 miles at all times, except in cases of fog or rain. They are read at 15 miles on days and nights ordinarily clear."

Special torches, fueled with turpentine, were used to send signals at night. One torch was placed in the ground. A flying torch was mounted on the end of the signal staff. By moving the flying torch form side to side relative to the motionless foot torch, the "1" or "2" could be read.

Telescopes and field glasses were an essential part of a signal party's equipment. Union officers were accountable for their equipment and were under strict orders not to let any fall into enemy hands.