Chevalier medium horizontal universal achromatic compound microscope
Date: circa 1840
Inventory Number: 1079
Classification: Microscope
Dimensions:microscope: 47 × 32.9 × 23.8 cm (18 1/2 × 12 15/16 × 9 3/8 in.)
case with jar: 62.5 × 32.9 × 23.8 cm (24 5/8 × 12 15/16 × 9 3/8 in.)
Material:
glass, paper, cardboard, wool, silk, velvet, cotton, mahogany, brass, steel, Accessories: 2 convertible objectives: 1, 2, 3 and 0,00,000; 2 oculars; simple magnifiers: 3 and 5, with support bracket; extension pillar; bull's eye stage condenser on jointed arm; forceps; 3 prepared slides; box of cover glasses; 1/100 mm stage micrometer; camera lucida; tall bell jar; padlock on chain; case with key; table of magnifications
DescriptionThis microscope is a medium universal stand for horizontal, vertical, and tilted use of the microscope. It is similar to CHSI 1093, but can also be used for inverted or "chemical" operation with the stage above the objective.
A round pillar screws into the top of the large flat case. The pillar has a compass joint at the top which carries a short bracket to which is hinged the tube of the microscope. The microscope body can be set horizontally or vertically. The microscope optical tube has interchangeable nosepieces: one straight and the other right-angled with 90 degree prism. The draw tube is lengthened or shortened without rack and pinion.
A square column is fixed to the short bracket and has a rack on which the pinions for the stage and substage mirror operate. Coarse focus is by the rack-and-pinion motion of the stage. Fine focus is by a vertical screw acting on a bracket for the stage plate.
The stage is removable and can be placed on an extension rod. The upper surface is blackened. There are two brass stage clips. There is a substage diaphragm wheel, and a plano-concave mirror.
Two objectives are convertible, each having three button elements. They are marked o, oo, ooo, and 1, 2, 3. They have bayonet mounts. There are two oculars.
For dissecting or aquatic use of the microscope as a simple microscope, there are 2 magnifying lenses for objectives, marked 3 and 5. A matching brass ring mount with a steel rod is stored in the parts box (lower level).
The instrument is equipped with a mahognay case with a drawer that can be locked. The steel key survives. The drawer has a removable lid. The fitted drawer and lid interior are cushioned with green wool. The removable mahogany parts box is lined with green silk and green velvet and has one tray. A conical, glass bell jar rimmed with brass sits on top of the case to protect the microscope when screwed into the socket there. There is evidence that the socket was relocated further back on the case top. A heart-shaped padlock secures the bell jar to the case by means of a brass hasp. It is marked as style "0," and was sold by the Wilson Bohannan Company in 1886. A brass chain currently attached to the padlock was also later addition to the instrument.
Other accessories include a camera lucida; stage condenser (bull's eye) on a jointed arm; stage micrometer (1/100 mm) engraved "Millimètre / en 100 parties"; forceps; 3 prepared slides; and a pill box holding circular cover slips. The pill box is covered in red and ivory paper. The lid is inscribed in brown ink, "H. I. B. / Microscopic / Covering / Glasses."
A handwritten, large, sheet of paper is glued to the underside of the drawer lid. It has a detailed table of magnifications and drawings of the stage micrometer with the camera lucida (also found in the case). These are probably by Professor Jackson, the owner.
Found in the case was the cast iron base of a laboratory stand with a threaded socket. It is painted black, with corrosion on the upper surface. A paper stamp of the owner, Arthur M. Edwards, New York is glued to bhe underside. In black ink over the maker's stamp is written "1/2 - 36."