When I was in the Boy Scouts more than a few years ago, you had to learn either semaphore or Morse code as a requirement for advancing in rank to First Class. Boy, this scout could have used this handy device back then. Behold, from the collection of the U.S. Naval Institute, the Pocket Signal Disk, U.S. Service Issue.
The Standard Novelty Company of La Jolla, California, started cranking out these pocket-sized cardboard decoders, replete with moving parts, in 1914. This artifact is the 1942 World War II edition. On one side, two spinning wheels are alignable to glean the meanings of Navy signal flags; on the flip side, there’s a Morse code component. Semaphore signal codes, the International Flag Code, special flags and pennants—they’re all here. As the disk’s sleeve declares, this is “an original time-saving device for instruction and review. . . . The student should study the selected code then as a TEST turn the corresponding wheel and endeavor to call the meaning of the characters as they appear in the opening. Having learned the codes, the actual sending and receiving of messages can be accomplished with little difficulty.”