In his own words in his Personal Narrative of Travels…. Humboldt carried "A compound microscope of Hoffmann, described in the history of the Cryptogamiae by Mr. Hedwig." (Alexander von Humboldt. Personal narrative of travels to the equinoctial regions of the New continent, during the years 1799-1804, by A. von Humboldt and A. Bonpland. translated from the French by Helen Maria Williams, 1814, p 39.)
Selected on-line examples of early 18th and 19th-century microscopes that may be similar to Humboldt's (and the instrument on display) from the Department of the History of Science at Harvard University include:
Microscopes are used to provide a magnified view of small objects or small portions of objects. In effect they bring objects very close to the observers eye and thus fill the field of view with the object.
Folding microscope with mechanical stage. The microscope is 12 ¼ “ high when closed, the largest of the folding tripod legs is 4 ½ “ long. Accessories include stage “fly” forceps (tips broken off), a live box, a specimen press, two objectives and an objective with attached lieberkuhn (front reflector). In the microscope image the the forceps are attached to the mechanical stage with the broken tip towards the objective. A two-part objectiveis screwed onto the microscope. Other accessories, arrayed in front of the microscope in the figure from left to right, include: a brass spring-loaded press for immobilizing frog's feet or fish tails, a second objective, a lieberkuhn objective (an objective with a built-in concave reflector for concentrating light on opaque specimens), and a brass and glass live box for holding small insects etc. while under observation.
The microscope and accessories are stored in black-velvet lined custom-fitted 13“ x 5 ¾ “ x 3 ¾” high box an inset ivory keyhole (see image of closed box). The microscope legs fold up by rotation around a center shaft to fit compactly in the box for storage. (see image of open box with microscope and accessories) Note that with the exception of the press, each of the accessories listed in the paragraph above has its own fitted location. The press was stored in an "extras" section next to the objectives block. The box is made from 3/8 “ mahogany with hand-cut dovetail joints and a bead around the top of the box (see closeup image of dovetailed corner), and hand fabricated brass hardware.
© R. Paselk
Last modified 13 August 2013