Zentmayer intermediate binocular and monocular compound microscope
Date: circa 1880
Inventory Number: 1015
Classification: Microscope
Dimensions:microscope: 44.5 × 20 × 19 cm (17 1/2 × 7 7/8 × 7 1/2 in.)
case: 53 × 25.9 × 22.5 cm (20 7/8 × 10 3/16 × 8 7/8 in.)
Accessories: Zentmayer objective with cannister: 1 1/2; paired oculars (3); Bicknell's achromatic condenser; rotating wheel diaphragm; polarizing eyepiece, polarizer by objective; camera lucida; plane glass window and brass socket; monocular tube; parts box with key; standing case with key.
Bibliography:Illustrated Price List of Microscopes, Microscopic Apparatus, Lenses, &c.
Illustrated Price List of Microscopes, Microscopic Apparatus, Lenses, &c.
DescriptionThis is a Zentmayer Intermediate compound microscope convertible between binocular and monocular. It has a flat tripod base with two turned pillars between which is the hinged joint carrying the curved arm above it. The primary body has binocular tubes. A substitute monocular tube is included in the accessories and currently has an eyepiece. (This is one of pair of matching eyepieces; the other is stored in a parts box). The coarse focus is by means of rack and pinion above the curved portion of the arm. The fine focus is by a screw acting on a lever on the objective's tube. There is a polarizer in the objective tube below this. Interpupillary distance can be adjusted by a screw operating both rack-and-pinion mechanisms at the top of each binocular tube. These raise and lower the eyepieces.
The microscope has a circular stage of damascened brass. On top there is a sliding glass-and-brass slide holder. It is locked in place by a pressure screw extending from the inner side edge of the stage. It has a socket for insertion of a stage forceps or similar accessory.
Substage equipment includes a condenser with a cup diaphram at the top and a diaphragm wheel midway down. (This is the so-called Bicknell's achromatic condenser.) The assembly is moved up and down by rack and pinion. Below this is a plano-concave mirror on a swinging arm. Both sides of the mirror have the silvering separating from the back of the glass.
This instrument is accompanied by a standing mahogany case with a lock and steel handle. Sections are cushioned by black velvet. A parts box lives in the case along with the spare monocular tube.
The parts box is mahogany and has its own lock and steel key. The inner wood fittings have become unglued, and the tray is supported by a rolled up piece of corrugated cardboard on which Dr. Lewis has inked, "Dr. F. T. Lewis / Harvard Medical School / Boston Mass." Cushions in the box are dark brown velvet and might have originally been black.
The box currently holds both its key and that to the standing case; the objective's cannister marked 1 1/2; three eyepieces belonging to the 3 matched sets (the other three are in the monocular and binocular tubes); a substage sleeve attachment with a wheel diaphragm, a substage sleeve currently empty; a plane glass window set into a knurled brass frame; polarizing eyepiece; and a camera lucida.
The box contains
Signedon base, front "toe": J. Zentmayer / Philadelphia
on objective can: J. Zentmayer / Philada.
Inscribedon base, front "toe": 1019
Historical AttributesThe following is written on a label that Dr. Lewis included with the instrument: "Zentmayer's 'INTERMEDIATE' pattern, / with 'Bicknell's Achromatic Condenser.' / Presented by Dr. John Bryant, A.B. '03; / M.D. (Harv.) '07.
The first of these Zentmayer stands was made for Professor Alexander Agassiz, according to the 1876 T. H. McAllister catalogue [lib.1028 and lib.1029].
Primary SourcesT. H. McAllister, Illustrated Price List of Microscopes, Microscopic Apparatus, Lenses, &c. 28th ed. (New York: T. H. McAllistar, 1876), 46-47.
T. H. McAllister, Illustrated Price List of Microscopes, Microscopic Apparatus, Lenses, &c. 22nd ed. (New York: T. H. McAllistar, 1876).
ProvenanceDr. John Bryant, Boston, MA, before 1905; gift to Ernst-Lewis Collection (inv. no. 15), Harvard Medical School, 1905.