Metal instrument (brass and steel) painted green. Originally believed to be one of only two remaining examples. Three now known to exist - at IWM and in a private collection. This instrument solved the navigational problems confronted by the Long Range Desert Group (and possibly SAS) in North Africa during WW2. A copy of the instruction manual, as well as a photo of model can be found on the S-Drive.
The desert war in N Africa came to an end in May 1943, so it is not known if this was used.
