Compound microscope by Hartnack, 1883
Signed on the tube: Dr. E. Hartnack / Potsdam
This is a microscope by Eduard Hartnack Potsdam of 1883. The instrument is made entirely out of lacquered brass and is the medium-size horse-shoe base offered by Hartnack.
The instrument has raw adjustment via rack and pinion, the fine focus is achieved via a prism-adjustment in the column. The table is equipped with a hard-rubber layer.
The horse-shoe base is protected by a fine leather-layer in order to avoid damage of the microscope and table and vice-versa.
The pull-out-tube has the standard-length of 160mm introduced by this workshop in Paris as it was still run by Oberhäuser. Illumination is achieved with a plano and concave mirror that has four bearings.
A cylindrical aperture-stop with a simple condenser-lens insert was to be moved in the optical axis under the table with rack and pinion (missing). The aperture was with a metal-slide under the cylinder for the condenser – the fitting is still present, the metal-slide itself is missing. The whole fitting for the cylindrical aperture stop/condenser may be swung out to the side.
Three objectives are screwed to a revolver. These are the objectives No. 4, No. 7 and Hom.Imm. No.1. The latter is kept in the matching signed brass cylinder. This objective would allow a magnification of 1100 with an eyepiece No.4 or 1500 with an eyepiece No.5. The objective for homogenous immersion was sold for Mark 200.- in 1883.
The mahogany case shows a brand-mark with the serial number 22868.
This microscope-stand was offered in 1883 and discontinued before 1894.