Compound microscope by Engelbert & Hensoldt, c. 1866-1868.
Signed: ENGELBERT U. HENSOLDT WETZLAR 172
Case: 22 x 13,5 x 10 cm
This instrument, manufactured in the heart of Germany between 1866 and 1868, region that still today mantains a leadership in optical industry, shows the typical elegant design of that time. The massive circular foot, in painted black brass with a diameter of 8 cm and 1,5 cm deep, gives a firm sustain. When in vertical position, the microscope is 29 cm high. The coarse focus is by moving the tube within its sleeve fixed to the arm. The main column, 11 cm high, mantains stable the stage by two screws; its dimensions are 6 x 7,5 cm and is formed by two plates fixed in a side by three screws, obtaining in this way a double section. Under the stage there is a knurled knob for fine regulation; it can be used comfortably with the hand in horizontal position.
The concave mirror is fixed on the circular foot by a pin. Light regulation is by a diaphragm with six holes of different diameter; a small brass lever, positioned under the stage, acts like a spring to stop near the hole. As the first microscopes of the Wetzlar Optical Institute, the stage has no clips. The fortunate user, during its work, can note signed on the stage: ENGELBERT U. HENSOLDT WETZLAR 172.
Into the case the microscope is packed without the optical tube. The optical outfit comprises only one objective signed 3, and the eyepieces 1 and 2. Another objective is present, but from the screw mount we can note it doesn't belong to this instrument; anyway is always a pleasure to be able to observe a piece of history from this famous firm, signed N° XVII ENGELBERT & HENSOLDT.