Leitz III M petrographic compound microscope
Date: circa 1948
Inventory Number: 1346a
Classification: Microscope
Dimensions:microscope: 37 × 14 × 23 cm (14 9/16 × 5 1/2 × 9 1/16 in.)
case: 42.8 × 22.2 × 26 cm (16 7/8 × 8 3/4 × 10 1/4 in.)
Accessories: objectives (2): P3b A 0.40 16,5:1 C and P6L A 0.65 45:1; ocular "0"; polarizing condenser; analyzer; box with 14 older petrographic slides [1346b]; standing case
Bibliography:Leitz Polarising Microscopes and Accessories
DescriptionThis is a Leitz petrographic compound microscope in the III M series with a tube for standard-diameter oculars.
The modified horseshoe-shaped base is made of cast iron coated in a glossy black lacquer. The handle arm above the inclination joint is curved and deep to permit manipulation of large specimens. The brass body is fitted with two slides holding an Amici-Bertrand lens and a tube analyzer. The ocular fits into a fixed tube. The objective is mounted in a centerable adaptor and held in the objective clutch changer. The coarse adjustment is by rack and pinion. The fine focus is by a micrometer screw equipped with a divided drum.
There is a rotating circular stage furnished with a divided limb and two verniers. A center plate is removable. The substage illuminating apparatus includes a "model c" system with a 3-lens condenser attached to a polarizer, a built-in iris diaphragm, and a swing-out lens. The substage mirror is plano-concave and mounted on a fixed arm.
This instrument is accompanied by a standing case with racks for lenses. The case is a Leitz case but does not belong to this instrument.
There is also a small, modern plastic box containing fourteen older petrographic slides of variable lengths and widths, which were typical before 1900. [See 1346b for details.]
Signedmarked on tube: Ernst Leitz / Wetzlar
marked on arm and objective, P 6L: E. LEITZ / WETZLAR [in achromat trademark]
on objective, P3b: Ernst Leitz Wetzlar
marked on arm: Germany
marked on objective and edge of mirror: GERMANY
on objective canister, 16mm: B. & L. O. C.
Inscribedmarked on tube: No. 392903
painted on foot: M-54
painted on case: M-50
FunctionThis instrument was used in mineralogy.
Historical AttributesThis instrument was used in the Department of Mineralogy and Petrography, Harvard University.
Primary SourcesE. Leitz, Inc., Leitz Polarising Microscopes and Accessories (New York: E. Leitz, Inc., 1936), 26.
ProvenanceDepartment of Mineralogy and Petrography, Harvard University; transfer to CHSI courtesy of Professor Stephen K. Dobos, 1985.