This is a superbly crafted cartographic mapping instrument. It is housed in its own high-quality purpose-built oak box. Made in the Netherlands from 1950 onwards. This instrument is from c 1956. it is a very high-quality military grade stereoscope that was generally used by photographic interpreters such as intelligence analysts but was equally useful for mapping activities. The stereoscope was used to examine 3D aerial photographic images. This instrument has a particularly useful capability to scan over the 3D stereo model using X and Y movement knobs, rather than having to physically move the aerial photographs. In the public and private sector it was also useful for photogrammetric interpretation for Forestry and Agricultural purposes. See also Bendigo RSL Collections Victoria item Number 6205.6P that shows the Old Deft Stereoscope in use at the Army Survey Regiment, Bendigo.This is an "Old Delft" scanning stereoscope with its reflecting carriage and legs. The Stereoscope is housed in its own purpose built wooden oak box that has dovetail joints, 2 x securing clips, 2 x handles and a lock (without key). The instrument is assembled by inserting colour coded legs into their matching slots."OLD DELFT SCANNING STEREOSCOPE ODSS III" "Patents Applied for" "OLD DELFT C4790" "MADE IN THE NETHERLANDS"royal australian survey corps, rasvy, fortuna, army survey regiment, army svy regt, asr