Optical tube for a geodesic (astronomical) device of the company "Emil Bush", made for Russia

An optical optical tube with an inverted image, made according to the Keppler system, for sighting geodesic (astronomical) instrument. The tube is equipped with an additional rotating prism for the convenience of measuring vertical (zenith) angles. The magnification of the device is approximately 6X. The lens is achromatic, the eyepiece is made according to the Huygens system. The ocular part of the tube has adjustment screws for installing and aligning the crosshairs of the threads in the field of view of the eyepiece. There is an inscription on the case of the eyepiece "EMIL BUSCH ACC, O. vo" (name of the manufacturer). Guarantee of authenticity.

The device is in good condition. The optics are clean. There are no crosshair threads in the field of view of the eyepiece and the end cap of the diagonal (zenith) prism.

The company "Emil Busch" ("Emil Busch") is an ancient optical enterprise in Germany, founded in 1792 in the city of Rathenow.  In 1845, Emil Busch became the head of the company. With him, Rathen optics becomes world-famous. Since its incorporation in 1872, the company has been called Emil Busch AG. Since 1927, the main shareholder of the company has been the Carl Zeiss concern.  The company produced, among other things, cameras, spyglasses and binoculars. The Second World War destroyed the economic life of the city. The companies Emil-Busch-AG and Nitsche & Gunther practically stopped production due to the loss of equipment. In 1946, on the basis of the Acc. company ”Emil-Busch-AG” and the company Nitsche & Gunther, the people's enterprise "Rathenower Optische Werke m.b.H." was created.