This compound barrel microscope manufactured by George Oberhauser in Paris is a transitional microscope from the classic “barrel or drum box”. Some call it the Fraunhofer model. It incorporates several advances such as a bull’s-eye magnifying glass for incident light, a tiny wheel condenser with three openings and finally a curious focusing system, consisting of a stage lifting screw. It also includes a brass scale divided into centimeters and millimeters, signed by G. Oberhauser. Likewise, the interior of the optical tube is signed by this manufacturer of German origin and French nationalized, which was established at No. 19 Plaça Dauphine in Paris. This model is referenced in B.C.C on pga. 33 with No. 63 and 194 with No. 371.