Bausch & Lomb Optical Co. Serial No. 3720, Pat. Oct. 3, 1876. The Harvard Model Microscope with inclination, c. 1885

The microscope is signed on limb: Bausch & Lomb Optical Co. and is marked on the other side of the limb with the 1876 patent date. The serial number is stamped on the wood case, 3720. It is an example of the Bausch & Lomb "Harvard" model microscope.

The body of the microscope is constructed in lacquered brass, while the base has a bronzed lacquered brass finish. The height of the tube can be extended by means of a drawtube. The drawtube has a Society Screw on the lower end to accommodate very low power objectives and other accessories. The coarse focusing is by push-tube and the fine focus utilizes a micrometer screw, which operates the patented B&L mechanism. The substage consists of a Wale type iris diaphragm. The mirror is adjustable on its swinging arm and is double sided with plane and concave glasses; it can be positioned above the stage to illuminate opaque objects. The microscope is supplied with two B&L eyepieces, two B&L objectives (marked 1/4 and 1-inch) with their brass canisters.

This model was supplied in several versions. This particular example is capable of inclining and has a coarse focusing by push-tube. There is a more simple version without inclination and a more advanced version that has both inclination and rack and pinion focusing (for example, see this).

^*The serial number, 3720, is stamped onto the wooden case. However, it is not clear if the first digit is a 3 or an 8. There are features on this microscope such as the lack of the 1885 patent date and the use of hard rubber for the mirror mounting that suggests the lower number is the correct serial number.

the Harvard microscope

Pat. Oct. 3, 1876

The following catalog description states that since the Faculty of the Harvard Medical School made suggestions for the design of this model, it was given the title the “Harvard Microscope”.

"The leading idea in the construction of this instrument was to get the nearest approach to the simple pattern, used so extensively in Europe, and combining with it those modern improvements, without which any microscope may be considered incomplete. Members of the Faculty of the Harvard Medical School have been interested in its construction and have made a number of valuable suggestions, which have been embodied in it. In recognition of the favor thus shown, we have given it its name. Considering the work, the various adjustments and price, it will be found to bear favorably a comparison with foreign instruments of similar construction. The stand is made entirely of brass and so proportioned that it will give the most effectiveness to the various parts. Although constructed so as to allow its convenient use in an upright position on an ordinary table, it still gives sufficient range of adjustment for all ordinary work. The base is of the horse-shoe form with a projection at the back to give it steadiness when the body is inclined. Coarse adjustment is by a sliding tube in a sleeve, provided with a spring which reduces the friction and retains a smooth movement; fine adjustment is by micrometer screw with milled head of more than ordinary size, acting on our patent movement. The main tube as a draw-tube with a mark indicating standard length. The stage is large and stiff and provided with spring clips; our iris diaphragm is attached to its lower surface in such a manner as to allow its centering and entire removal for oblique light. The mirrors are plane and concave and swing with the mirror-bar to any obliquity below the stage and above it for the illumination for opaque objects. No.515A is with solid pillar and arm while B is arranged with joint for inclination of the body."

Bausch & Lomb Optical Co. Serial No. 3720

Pat. Oct. 3, 1876

The Harvard Model Microscope with inclination, c. 1885

The microscope is signed on limb: Bausch & Lomb Optical Co. and is marked on the other side of the limb with the 1876 patent date. The serial number is stamped on the wood case, 3720. It is an example of the Bausch & Lomb "Harvard" model microscope.

This model was supplied in several versions. This particular example is capable of inclining and has a coarse focusing by push-tube. There is a more simple version without inclination and a more advanced version that has both inclination and rack and pinion focusing (for example, see this).

Three versions of the Harvard Model microscope