This 1946 cover photo shows a stereoplanigraph, described as “one of the most universal and elaborate photomapping instruments ever constructed.”

It was “used for plotting topographic maps from stereoscopic photography, and for aero-triangulation from aerial strip photography.

The floating point that is viewed in the stereoscopic model by the operator can be moved in three dimensions by means of the two handwheels and the foot pedal.”

It was featured in the cover story, “War-Developed Equipment for Peacetime Use” which described construction equipment, surveying and mapping instruments and bridging techniques being demonstrated at Fort Belvoir, Va., by the Engineer Board, the U.S. Army Corps of Engineers’ research and development wing.

Many of the items had been developed by the Board during World War II and were revealed thanks to the removal of wartime secrecy restrictions.

Others, including the stereoplanigraph, were captured German instruments. “Studies by the Board of the captured German surveying equipment indicates that the Germans were far advanced in the design of certain types of instruments.”