DESCRIPTION:
We are grateful to Dr Joseph Zeligs for providing the images and a description of this microscope. This is a simple microscope which incorporates a Wollaston-type camera lucida. The camera Lucida itself follows Wollaston's original description closely. It features a double-refracting (4-sided in section) prism, so that the image is not reversed.

The prism assembly mounts via a clamp to the 3-part telescoping brass stem, which itself clamps to a table or support. The top portion of the stem has a series of settings (2, 3, 4, 5, 7, 10, and "D") to change the distance of the instrument from the drawing paper, which are used to calibrate for enlargement or reduction of the size of the drawings.

The case is beautifully fitted, with non-rectangular dimensions and wooden interior stays. It is covered in fishskin on all 6 surfaces and lined with green plush, like typical 18th century outfits.

It has Wollaston's original swiveling 'pupil guide' to help position the eye such that the upper portion of the pupil faces the prism and sees the subject to be drawn and the lower portion of the pupil faces the drawing paper. There are also two integral hinged corrective lenses, as advocated by Wollaston, which serve to roughly equalize the accommodation required by the user's eye to the paper versus the subject. For those who are far—sighted, the convex lens swings below the prism, facing the drawing. For those with near—sighted vision, the concave lens is swung between the prism and the subject.

The prism assembly mounts via a clamp to the 3-part telescoping brass stem, which itself clamps to a table or support. The top portion of the stem has a series of settings (2, 3, 4, 5, 7, 10, and "D") which are used to calibrate for enlargement or reduction of the scale of the drawings.

The simple microscope is designed to be integrated with the camera and in fact, has no provision to allow it to be used without it. A brass slider with 4 lenses fits within guides in front of the prism to be set at indicated spots for each lens. All lenses are relatively low power, the highest about 25X.

A brass stage features two brass bar extensions, by which it attaches to slots on either side of the brass housing for the camera lucida. The stage has provisions for specimen sliders, a stage forceps and a fish—plate, all present in the outfit. One of the stage clips for sliders is largely missing. There is also a unique Lieberkuhn, which screws into a brass mount. The rectangular mount has two brass locating pins that serve to position it on the brass-bound camera lucida such that it is in the optical axis, directly in front of the lens slider, and could potentially provide illumination on opaque specimens. This Lieberkühn stores on one of the finished wooden stays in the case, facing downward and against a glass protector for its silvered surface. A lieberkuhn would be used to view opaque objects such as a fly or a leaf attached to the stage forceps.

To use the microscope, one must view specimens via the prism, but the optics are clear. Focus is only via sliding the stage on its dual bars, which is adequate for the low power lenses . The fish plate would not be useful at the powers supplied and does not fit such that its window can be in the optical axis, which suggests that the maker, although an exceptionally fine craftsman, was not so familiar with microscopes per se.

The sliders are a fine set, numbered 1—6, with all specimens and circlips present. The craftsmanship and condition are fine throughout, see images.

This is the earliest example of a camera Lucida attachment for a microscope that we are aware of, let alone a dedicated camera lucida-microscope system, and we do not know of any other similar examples.

HISTORY OF THE CAMERA LUCIDA FOR THE MICROSCOPE:
The idea of a camera lucida is first known to be proposed by Kepler in 1611, but there is no evidence it was constructed prior to the early 19th century. William Hyde Wollaston is generally credited with the invention, and his patent of 1806 shows how it uses a specially shaped prism. The first official published description was in the Philoscophical Magazine of 1807. He did not initially adapt it to compound microscopes and this came later. Early on however, it seems it was adapted to this simple microscope configuration and comes with a case and accessories of a style that date to the late 18th and early 19th centuries. For a more detailed history of the camera lucida for the microscope, and other examples and variations, please see the dedicated camera lucida page. You may also wish to read: the article 'Wollaston's Experimental Camera Lucida at the Whipple Museum' in the Bulletin of the Scientific Instrument Society, Vol 144, March 2020, pp41-43.

We are very grateful to Dr Joseph Zeligs for sharing his description, references, and images of this microscope with us.