Spies Like US: Secret Messages
Yesterday I wrote about homing pigeons in the first installment of this spy series. Today, let’s look at other ways spies have relayed messages over the years. One of the cooler ways involved microdot cameras. Simple in construction and easy to hide because of their tiny size, microdot cameras were able to produce a negative 300X smaller than the original document. Once reduced—sometimes even to the size of a period!—a decoder could use a microscope to read the secret message. The photo here shows what a 1955 KGB version of the camera looked like. Keep in mind that this picture is almost to scale. The actual size of the camera was about the size of a grown man’s big toe! You might recall microdots being mentioned in Mission Impossible 3. In the movie, the microdot was hidden at the back of postage stamp and contained a magnetically stored video file.
Another way spies transported messages was by using invisible ink. Women were often used as carriers because they were less susceptible to searches. Invisible ink often uses a compound of cobalt chloride, glycerine and water. There’s one chemical for writing the message and a second to develop it. MI6 spies were said to use semen as an invisible ink from 1909-1949. Mansfield Cumming,the first chief of the SIS, had been trying to find a good invisible ink, and was quoted as saying: “Heard from C that the best invisible ink is semen.” This might explain why you’ve never seen James Bond writing any letters in any of the 007 movies!