Giant periscope [Das Mastfernrohr] : German Army
|Title||Giant periscope [Das Mastfernrohr] : German Army|
|Object type||Optical equipment|
|Date made||c 1917|
German portable telescopic periscope, mounted on a two- wheeled carriage, both painted green. The periscope consists of a steel telescopic mast with upper and lower optical systems attached. The mast is carried in trunnions on the carriage. The periscope has gears to elevate, level and align the optical systems. They also adjust the inclination of the reflector and rotate the mast around its vertical axis.
The upper optical system consists of a short rectangular tube which contains a protective window. Behind this is a mirror, placed at an angle. The rectangular tube is attached at right angles to a conical casing, which contains two achromatic lenses. At the bottom of the conical casing is a large lens which has a crosshair on the glass. The lens is pitted near the centre. A strip of leather is attached around the bottom edge of the cone.
Called 'Das Mastfernrohr' [the mast telescope] by the Germans, the service history of this First World War giant periscope is unknown. It is believed to be one of only three still in existence and was one of the pieces of military hardware ceded by Germany under the terms of the 1918 Armistice.