This is a remarkable example of a "broken telescope" style pilot balloon theodolite, designed by Dr. Koelzer and manufactured by Edouard Sprenger in Berlin, Germany, circa 1930-1940. This precision optical instrument features a black lacquered finish with brass horizontal and vertical limbs, used historically for tracking meteorological balloons to determine wind speed and direction at various altitudes. It is a complex, "two-man operation" instrument marked with serial number 8397 and "D.R.G.M." (Deutsches Reichsgebrauchsmuster), indicating a registered design. The piece includes a large three-screw leveling base and a dedicated container for a stopwatch. The instrument is in good general condition with a well-preserved finish, showing minor surface cleaning and paint retouching from a mid-2000s restoration, along with typical light wear to the brass scales and adjustment knobs consistent with professional use. Note that the original transit case is not included with this lot. H 13", W 13.5", D 10". From the collection of Dale Beeks. Please see photos for condition.