Bausch & Lomb Optical. Co., Rochester N.Y.

An early and uncommon B&L microscope with screw tube focusing, c. 1875

Bausch & Lomb Optical. Co., Rochester N.Y.  Early B&L microscope with screw tube focusing, c. 1875

Bausch & Lomb Optical. Co., Rochester N.Y.  Early B&L microscope with screw tube focusing, c. 1875

Bausch & Lomb Optical. Co., Rochester N.Y.  Early B&L microscope with screw tube focusing, c. 1875

Bausch & Lomb Optical. Co., Rochester N.Y.  Early B&L microscope with screw tube focusing, c. 1875

Bausch & Lomb Optical. Co., Rochester N.Y.  Early B&L microscope with screw tube focusing, c. 1875

The claw-footed base is black japanned iron with a spread of 5-3/4 x 5-1/2 inches, and supports the two brass 2-3/4-inch-high tubular pillars of this instrument. A japanned Lister limb, 6-1/2 inches long, screws on the trunnion; the lower 2 inches of the limb form the tailpiece. The 1-9/16-inch single concave mirror is on a ball-and-socket gimbal.

The stage is fixed to the limb, is 2-1/2 x 3-1/4 inches, has a 1/2-inch central aperture, and is fitted for stage clips; beneath the stage is a revolving disc of diaphragms. The upper end of the limb is attached to a sprung tube, 3-1/4 x 1-3/16 inches.

The body tube is 7-1/2 inches long and fits into the outer tube; there is a screw focusing adjustment at the lower end; thus the microscope focuses by twisting the main tube. The screw threads of the focusing adjustment are rather fine allowing slow movement of the tube for accurate focusing. The stage, diaphragm disc, mirror case, ocular, and objective are of brown-colored hard rubber (Vulcanite).

It is signed on the tube in fancy script, "Bausch & Lomb Optical Co., Rochester N, Y," This is one of the earliest models made by this firm, possibly the firm's first production model; the construction is unique, and it was discontinued sometime before 1878. The screw tube focusing was later replaced by a sliding tube or rack and pinion (see the later, but similar, Educational Model also in this collection). The microscope was found without its storage case and no serial number; however, the underside of the base has eleven punched indentations of uncertain significance. A similar microscope is in the Billings Microscope Collection (see: fig 134 on page 72 of the catalog); it differs from the present example in having a brass limb as opposed to the cast iron limb used on the microscope shown here. An additional example with the iron limb is in a private collection; it bears the serial number 32, which is stamped onto the inside bottom of the wood storage case.

Home Page-Antique Microscopes       Site Index

www.antique-microscopes.com