Headlining Bonhams Cameras, Scientific Instruments and Mechanical Music sale in London’s Knightsbridge on October 29th is a rare three-rotor German Enigma enciphering machine (1944) by Heimsoeth & Rinke, Serial No. 19088. It is expected to fetch between £30,000 and £50,000.
The Enigma comes complete with its original I, III and V rotors with Bakelite thumbwheels and matching serial numbers, its makers plate stamped A 19088/jla/44, and its standard QWERTZ keyboard with keys made up of white lettering on black background. Its battery switch, vacant battery box, complete set of bulbs, ebonite plug board, set of three plug board cables, and set of instructions applied to the lid interior together with a spare bulb rack are also original. The machine rests in an oak carrying case with a hinged lid and a fall front with a locking mechanism; when closed, the case measures 6 by 11 by 13in (15 by 28 by 33cm).
The first machines to be used in a military capacity only had a fixed set of three wheels. Later, a set of five wheels were used so that they could be interchanged to dramatically increase the number of variants available. Each machine could use the interchangeable wheels from any enigma, so to find a matching set of wheels with the same serial number as the Enigma is rare.
The addition of a plugboard or Steckerbrett was a decisive change to the Enigma machine. It switched the letters before they entered the rotors which meant that, for example, if you pressed ‘A’, ‘P’ would be transmitted and then mixed up again in the rotors. Thirteen cables could be inserted to switch thirteen pairs of letters. Only by setting a receiving enigma to the exact same settings as the sending enigma could you decipher the message.
