Cuff-style compound microscope made by J. H. Tiedemann (No. 133)
Age: 1790–1810
Made by: J. H. Tiedemann
Made in: Stuttgardt, Germany

This is a compound Cuff-style microscope made in Germany at the end of the 18th Century by Johann Heinrich Tiedemann. The microscope body consists of a brass tube with the single-lens objective screwed to one end and a multi-lens eyepiece to the other. The body press-fits into an arm mounted to the top of the support pillar. This pillar consists of two rectangular brass rods screwed together via spacers at the top and bottom. This creates a slot into which is placed the focusing mechanism and mirror mount. Focusing is accomplished via a rack & pinion. The rack is attached to the sample stage and the focusing pinion mounted to the pillar. Thus, focusing moves the stage relative to the microscope body. The sample stage is cruciform, like the Cuff instrument, and has two mounts for stage tools. One of the stage mounts is a hinged arm. There is only one objective remaining with this instrument (No 4) and no accessories. Imaging is good with some chromatic aberration but poor contrast owing to the lack of a condenser. The microscope body is engraved "Tiedemann, Stuttgardt".

Tiedemann was innovative in microscope optics. In the 1780s he constructed a microscope objective with a high magnification (focal length of 2.2mm) that was considered to be one of the finest in Germany. At that time opticians were experimenting with resolution and magnification by modifications of the eyepiece. This instrument is a good example of this concept as its eyepiece consists of four biconvex lenses, yet the objective is a single lens element. Tiedemann also is known for his microscopes having an incline support pillar, with the hinge placed at the base of the support. Other makers of the time (e.g., Adams, Martin) placed the incline hinge higher up the pillar. This microscope is presently mounted to a single piece of wood (post Nachet), however originally it was mounted to the bottom of a wooden storage box. Later in his career Tiedemann dispensed with the box and replaced it with a flat brass tripod. This innovation is considered by Daumas* to "free the microscope" from it's connection to the first half of the 18th Century. This microscope was instrument No. 74 of the Nachet Collection of Paris. Tiedemann also made drum microscopes, a rare example of which is microscope No. 134 in the Golub Collection.

*Daumas, 1972, p166.

Microscope featured 6/2016