The oldest Zeiss instrument in the collection is a small microscope with a horseshoe base and a round pillar. The body-tube is attached to the pillar by a short arm and focusing is by the screw on top of the pillar. A swinging mirror is attached to the bottom of the stage. The instrument has a mahogany box in which it lies sideways. Signed: 3973. C. Zeiss, Jena.