CCDS MICROSCOPE:

c. 1895

Signed on the foot: Bausch & Lomb Optical Co, Rochester New York & New York City

Serial Number:18738

DESCRIPTION

HISTORY

DESCRIPTION:

The instrument has the serial number of 18738 imprinted on a disc on the rear of the foot dating it to 1895. This was a top of the line instrument with a panapoly of adjustments. Its stage features a rotating calibrated silvered scaled motion as well as calibrated X and Y motions. It has both rack and pinion coarse focus and a calibrated long lever fine focus patented by B & L. It has a Kohler condenser assembly. The substage vertical motion is by rack and pinion. It features a centerable midportion and a separate iris which can be swung out of the optical axis and, and in addition, it has a rack and pinion adjustment to offset it from the central axis. The achromatic condenser lens can also be swung out the axis separately. The tension of the screw supporting the lister limb to the pillar is adjustable via an ivory handle. The outfit includes:

HISTORY OF THE CCDS MICROSCOPE

This microscope was just one level below B & L's best instrument. B & L started to manufacture microscopes under their own name in 1876. As the years passed they moved from a variety of forms of feet to the modern horseshoe foot which became the standard for many decades clear into the mid-20th century. Description from the 1898 B & L catalog:

In relisting this stand, we offer an entirely remodeled instrument, new stage and substage, and have been able at the same time to materially reduce the price. The stand is of brass throughout, highly finished and lacquered. The base is of the horseshoe form, but with the back claw projecting to form a tripod support, insuring the greatest stability in all positions of the body.The pillar is massive, of graceful proportions, and the joint has locking lever for securing the body at any angle of inclination. The substage is our New Complete Substage, described and figured on Pages l7 and l8. The stage is our New Mechanical Stage, described and figured on page 19, is revolvable on its axis and has centering screws. The fine adjustment is by micrometer screw acting on the triangular bearing of the arm, the construction being our improved (patented) device doing away with set-screws and springs, and entirely eliminating lost motion either through wear, relaxation of parts, or other cause. The head of the micrometer screw is graduated for measuring the thickness of objects. The coarse adjustment is by diagonal rack and pinion of very great delicacy. The bearing of the sliding parts is not made directly upon the body tube, but upon a separate piece of metal attached to the body tube, whereby we obtain much greater accuracy in fitting and greater stability than can be had by the old method of construction, at the same time giving the proper combination of metals to insure the least amount of wear and least friction. Especial care is given to the fitting of the pinion box, our construction preventing the pinion from ever becoming loose. The main tube has graduated draw-tube work in a cloth-lined sleeve. The Abbe condenser, 1.20 N. A. is part of this stand. Each CCDS microscope is furnished in a polished case, with nickeled handle and lock, and with receptacle for accessories.

Its complex substage was invented by the famous German Professor August Kohler who was the scientific director for the firm of Carl Zeiss, and Kohler's idea was licensed to B & L. The American patent was granted to Bausch and Kohler as the inventors. though Koehler was the true original inventor.