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G. Gerlach  - Warszawa (Warsaw Poland) Pilot Balloon Theodolite

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gerlach.jpg (14035 bytes) GERLACH WARSZAWA, No.86693. Made of solid brass, blackened with nickeled scales.  32cm (12.5 inch. high) Diam. Left to right 20 cm (8 inch.). Horizontal scale with 2 verniers two vertical circles 1 with two verniers and one with a single vernier.  This instrument was sold as an "early 20th century" instrument by a dealer in Germany. (I would guess 1920's)  The Gerlach uses positively engaging tangent screws but does not incorporate micrometers.  It has a detachable compass, a gun site for rough positioning, but no wide angle finder scope. 

This instrument can be read from the operator's position or by a second person on the opposing side of the instrument.   It is unusual in that the telescope is not fixed in alignment to the horizontal micrometer.  When you loosen the set screw (what would normally be used to adjust the position of the horizontal circle to the tripod base) the telescope moves vs. the horizontal vernier.  The horizontal circle is fixed in its relationship to the tripod.  The system works but in some orientations it may be hard to read the horizontal circle.

It is possible that the Kölzer-Sprenger balloon theodolites and later R & A Rost (after Dr. Kölzer-Sprenger) Balloon Theodolites are later variants of this design.