Nachet large compound microscope
Date: 1862
Inventory Number: 1157a
Classification: Microscope
Dimensions:microscope: 34.5 x 11 x 15.5 cm (13 9/16 x 4 5/16 x 6 1/8 in.)
case: 13.7 × 35.5 × 22.1 cm (5 3/8 × 14 × 8 11/16 in.)
Accessories: 6 objectives in box (1157b) with 1 substage condenser; oblique prism condenser; 3 oculars; 1 cup diaphragm, 1 diffuser, ; camera lucida; stage and eyepiece micrometers; liquid trough; 3 dissecting knives; prepared slides in box (1157d); plain slides; cover glasses; bull's eye on jointed arm(1157e); Amici's illuminator prism with stand (1157f); compressorium (1157g); case with parts box (1157c).
Description1157 is a fine example of the type of compound microscope that Nachet et Fils called the "grand modèle." For descriptive purposes and better comparison with a similar but not identical, early "grand modèle" by Nachet, the assembly is divided into these components, each with their own images and written details:
1157a: the microscope with eyepieces
1157b: box of objectives and condensers
1157c: microscope case and parts box, with diverse accessories
1157d: box of slides
1157e: bull's eye condenser
1157f: Amici illuminating prism, Nachet-style
1157g: compressorium
1157h: manuscripts found in case
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The Nachet et Fils microscope 1157a has a horseshoe-shaped base with a long heel. The base is brass, weighted with lead, and darkened on its upper surface. The stand consists of two round pillars topped with an inclining joint. This joint is attached to the stage, and the stage carries the upper part of the microscope.
The tube is carried in a sleeve attached by a ring mount to bracket on the main pillar of the microscope. This pillar is fixed to the back of the stage and the rotates with the stage. The upper part of the tube has a slot for inserting an eyepiece micrometer. A screw attached to the bracket for this slot focuses the micrometer. A screw in the section of the tube below this locks the micrometer orientation as desired. The nosepiece is integral to the tube. Coarse focus is by sliding the tube. Fine focus is by a micrometer screw in the top of the pillar.
The rotating round stage has a black glass insert. There are two stage clips.
There is a substage ring mount for cup diaphrams (one is present in the case parts box) and a diaphram wheel below this. Both can be raised and lowered by means of a lever below the stage. The substage mirror is plano-concave and held in an octagonal brass frame. It has a knurled screw for adjusting its angle. The mirror is fork-mounted on an articulated arm below the stage.
The microscope has 3 eyepieces (1, 1, 2). Each has a sliding cover on the side of its tube, which is opened when the eyepiece micrometer slide is used.
The six objectives (0, 1, 2, 3, 5, 7) are stored in a little box (1029b) along with a Nachet oblique prism and a substage condenser.
Other accessories are included in the fitted mahogany case with a lift-out parts box (1029c). The area below the parts box holds more accessories, including a compressorium (1029g), Amici illuminating prism (1029f), and part of its stand. There is also a bull's eye condenser (1029e) in the case.
A manuscript written in French on rules for observing with the microscope was removed from the case and put in the instrument's file. A business card of Dr. Algernon Coolidge remains in the case. (These are recorded as 1157h)
All that remains of the leather case (mentioned by Dr. Lewis) are some straps in the parts box of the microscope's mahogany box.
SignedEngraved on arm: NACHET / ET FILS / à Paris / rue Serpente, 16.
Historical AttributesFormerly Ernst-Lewis collection no. 157.
Dr. Lewis notes: "From Dr. Edward D. Churchill in 1940. It came to him from the heirs of Dr. Algernon Coolidge, and possibly belonged to his father [Dr. Algernon Coolidge. Senior]. The brass trimmed mahogany box with full equipment was in its leather case. Since this microscope would have been out of date for Dr. Coolidge Jr. (AB 1881; MD 1886; Professor of Laryngology, 1911-1925), it in all probability belonged to his father, Algernon Coolidge, MD 1853, University Lecturer 2nd half 1867-1868, Instructor in Pathological Anatomy, 1865; Lecturer on Tumors, 1868-1869, in connection with which this microscope would have been excellent equipment."
Primary SourcesMaison Nachet & Fils Fabrique d'Instruments de Micrographie (Paris, 1872), 6, 26.
On Nachet's oblique illuminating prism, and on Nachet's mounting of Amici's illuminating prism, see John Quekett, Practical Treatise on the Use of the Microscope, 2nd ed. (1852), 119-120, 204.
ProvenanceDr. Algernon S. Coolidge, Sr, Harvard Medical School; Dr. Algernon S. Coolidge, Jr, Harvard Medical School; Dr. Edward D. Churchill, before 1940; gift to Ernst-Lewis Collection of Microscopes (inv. no. 157), Harvard Medical School, 1940.