carbons original to B&L carbon-arc projection microscope
Date: 1950-1960
Inventory Number: 1998-1-1637a
Classification: Microscope
Dimensions:box: 6.2 × 26.5 × 13.3 cm (2 7/16 × 10 7/16 × 5 1/4 in.)
instrument: 15.5 × 0.5 × 0.5 cm (6 1/8 × 3/16 × 3/16 in.)
DescriptionCarbons to be used with a Bausch & Lomb projection microscope intended to be used with a carbon arc lamp.
The microscope arm is attached to a black metal box serving as the base and seat of the microscope stage. There is a monocular eyepiece whose top is equiped with a prism that swivels. The prism projects an image on a screen. The body tube is aluminum and fits into a large cast metal housing, which carries a slotted wheel diaphragm with a spring-clip lock above the revolving nosepiece. A vertical column descends from a corner of the metal housing into a hole in the base. This arm is part of the linkage between the gearing of the nosepiece and the gearing for the set of condensers below the stage.
The quadruple nosepiece holds 3 objectives (10X, 21X, and 43X). The fourth opening is marked for a 2X power objective. It holds a vertical illuminator fitted with a hinged mirror, iris diaphragm marked in f-stops from f/4.5 to f/22, and a 48mm macro lens.
Coarse focus is by rack and pinion. Fine focus by a micrometer drum with each division equal to .002 mm.
The mechanical stage is built-in to the top of the base. There are 4 condensers mounted on a wheel below the stage. Rotating the quadruple nosepiece causes this wheel to rotate so that a given condenser is always matched to particular objective. A removable square panel on top of the base gives the user access to the condensers.
An circular glass window on the right side of the base is for the input of light from a carbon arc lamp (not present).