Box-Type Microscope on a Cylindrical Base (No. 261 )

Age: 1750–1760
Made by: unknown
Made in: probably Holland
Aquatic position

This microscope is a Box-style compound microscope mounted on a cylindrical mahogany pedestal that includes the illuminating mirror. A removable shagreen-covered mahogany top screws onto the base to protect the instrument for storage. The microscope itself is a compound instrument with the typical objective, field, and eye lenses. The field lens is mounted in a removable cardboard tube that presses into the upper drawtube. This positions the field lens halfway between the objective and eyelens.

Lenses are fixed in hardwood mounts at the ends of the cardboard body tubes. The main body tube is covered in black fishskin. The field tube and drawtube are covered in green-dyed vellum. Gold tooling decorates the exposed top of the eyelens drawtube. Samples are illuminated by a concave mirror mounted on a pivot inside the cylindrical base. Light can be attenuated by rotating a brass collar in the center of the base to one of four aperture positions. The circular pedestal can be unscrewed exposing the mirror. Focus is via rack and pinion. There is no fine focus. The microscope is mounted to the sliding rectangular support pillar via a rotatable mounting mechanism allowing the microscope to be oriented horizontally to the aquatic position.

Imaging is quite good with minimal spherical and chromatic aberration. There is only one objective with this instrument and it yields a total maginification of approximately 20x.

This microscope is probably Dutch in origin.

Featured 07/2012

Sat, Jun 30, 2012