BAUSCH & LOMB VINTAGE MICRO-INTERFEROMETER METALLURGICAL MICROSCOPE W/WOOD CASE

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BAUSCH & LOMB VINTAGE MICRO-INTERFEROMETER METALLURGICAL MICROSCOPE WITH WOOD CASE & ACCESSORIES

You are invited to submit bids for a superb Bausch & Lomb Optical Company (B&L) vintage binocular Micro-Interferometer Metallurgical Microscope with a nicely fitted wood case and a compliment of accessories. The accessories include a mechanical stage, a vertical illuminator with power supply, a rare B&L 13x Interferometer objective with its own set of accessories and storage case, and two (2) sets of paired eyepieces. This microscope bears the trademark “B&L” signature engraved on the face of the binocular head and a serial number “RB1656” on a metal plaque found atop the limb. The serial number dates this instrument to the year 1954.

In addition, on the metal plaque at the top of the limb that also contains the serial number one finds two (2) US Patent Numbers (see close-up image): 2,101,936; and 2,117,161. These numbers refer to specific improvements to the design of the microscope by B&L employees and assigned to the B&L Optical Company. The first Patent number refers to a 1937 US Patent granted to G.S. Gallasch for a design that allows for detachable and interchangeable body tubes. The second Patent number refers to a 1938 US Patent granted to H. F. Kurtz and G.S. Gallasch for a fine adjustment slide mounting for this microscope.

A metallurgical microscope is somewhat similar to a biological microscope, but it is especially designed for the examination of opaque materials including, but not limited to, metals, minerals, glass, ceramics and other substances that generally cannot be effectively examined with transmitted light on a glass slide with a coverslip. The emphasis with this type of instrument is on the close-up examination of the surfaces of opaque specimens with the use of incidental illumination rather than transmitted light.

A key component of this instrument is the rarely found B&L Interferometer objective lens with accessories that is included with this instrument. A complete description of this objective and its intended use is found below under the heading, “Detailed Description.”

Metallurgical microscopes are used in such varied fields as forensics (for microscope examination of objects involved in criminal acts – CSI), archaeology and paleontology (close-up examination of artifacts and fossils), gemology (examination of precious semi-precious gems for facets and flaws), metals and ceramics manufacture (detection of production flaws), geology (surface examination and identification of crystals and minerals), computer chip and electrical parts manufacture (quality control), and by coin and stamp collectors (for examination of minute details that define value or rarity) among many other uses too numerous to mention. The capability of interferometry associated with this instrument adds another valued dimension to this metallurgical microscope.

DETAILED DESCRIPTION:

This microscope is built upon a very large and heavy horseshoe-shaped base with integral nicely sculpted dual pillars that rise to a trunnion joint. This joint supports the rest of the microscope, including the continental style arm, the body tube, the stage and a sub-stage assembly. The trunnion joint allows the microscope to be tilted at any angle from the vertical to allow for the comfortable viewing of specimens atop the stage.

Coarse focus is by rack and pinion controlled by a set of hand knobs found just below the top of the limb. Fine adjustment is via a pair of micrometer knobs found below the coarse focus knobs further down the limb. The control knob on the right side of the instrument includes a vernier and scale that indicates that one division on the vernier against the scale amounts to a movement of the body tube of just 0.002 mm.

The microscope is equipped with a very large 112 x 130 mm rectangular stage plate equipped with a robust x-y mechanical stage with position verniers and scales on both axis and a spring loaded slide retainer. Of special interest is the fact that the mechanical stage is attached at the front of the stage rather than at the back as in a standard biological microscope. There is good reason for this nuance as the entire stage can be raised above or below the trunnion joint. If the mechanical stage were to be mounted at the back of the stage, it would impact the trunnion joint and thus the stage could not be lowered below the joint.

The stage elevation is controlled by means of the rack and pinion system with a control knob found on the right side of the instrument. This unique feature, not found on a standard biological microscope, allows large, thick objects to be accommodated atop the stage. The stage can be lowered significantly below the trunnion joint so that the surface of a thick object can be examined microscopically and to permit the effective use of the interferometer objective.

Under the stage is an articulating plano-concave mirror assembly that is attached to the base of the stage support. This provision allows for the alternative examination of slide mounted transparent or semi-transparent specimens by transmitted light, which contributes significantly to the versatility of the instrument.

The lower end of the body tube of this microscope is equipped with a multi-part vertical illuminator assembly. This unit is equipped with an internal slider that contains both a glass and a prism reflector that directs light from the illuminating unit through the objective to the object. In turn, the light reflected off of the specimen forms an image that is directed back up the body tube to the eyepieces and ultimately to the observer. The unit is also equipped with both field and aperture diaphragms, controlled by levers, that permit full control of the incident light beam, as well as, a port for the insertion of a filter, if desired. The illuminating unit extends horizontally from the vertical illuminator and is so designed so as to maintain a constant alignment of the light beam. The orientation of the illuminating unit can be adjusted to almost any horizontal angle forward of the limb by means of a lever with its own twist lock mechanism.

NOTE: This is the original B&L illuminator that was supplied with the instrument. However, it came to us without the accompanying B&L 6 volt power supply / transformer. We modified the unit to accept a 12v incandescent bulb and to run on 12 volt DC power provided by a plug-in 120v to 12v line transformer. This arrangement provides adequate illumination. A spare 12v bulb is provided.

A key element of this instrument is the B&L Interferometer Objective that comes with its own felt-lined storage case along with a set of accessories. The lower portion of the objective lens is engraved with the name and address of the manufacturer along with, “0.25 NA 13X 215mm T.L. [tube length] USE WITHOUT COVER GLASS” along with a serial number, “RD4788,” which means it was manufactured in the same year (1954) as the microscope itself.

The top of the interferometer objective has a standard RMS thread. The base of the objective has a threaded port at its center that permits the attachment of a reflector lens – either a 10% or a 20% reflector lens – both of which are included in the storage case. The body of the objective lens can be rotated a full 360 degrees and is so designed that the reflector lens will mate directly with the surface to be examined. Once the base of the objective impacts the specimen, the lens barrel will retract into itself for a few mm as focus is achieved similar to the action of a standard spring-loaded objective. Two adjustment screws are found on the top of the wide flange on the lower end of the objective. These screws permit adjustment of the angle of impact of the reflector lens to the specimen so that it is flush with the surface to be examined.

This lens is attached to the vertical illuminator assembly at the base of the body tube with a special objective adaptor with thumb handles that permits quick attachment or removal of the lens from the illuminator assembly. Included with the objective lens is a 556 nanometer (green) filter that is used in conjunction with the objective lens. It is inserted into the filter port found on the leading edge of the vertical illuminator. When the objective lens is set onto the specimen, focused and properly adjusted it produces an interference pattern that corresponds to the height variations in the sample being examined.

To illustrate some of the practical uses of this micro-interferometer microscope, included with this listing are images of interference patterns produced by some common specimens microscopically examined by this very instrument. The first example is that of a glass coverslip atop a glass slide. The second is that of a scratch on the surface of a compact disc (CD). These images demonstrate that the microscope performs as designed and that it can still be used for micro-interferometry to this very day.

NOTE: The 13X Interferometer objective can also be used to examine surfaces in a standard fashion by removing the reflector lens. Without the reflector lens in place, it will perform just like any standard 215mm T.L. objective and will provide sharp images of surface features of opaque objects illuminated by the vertical illuminator.

Also provided with this microscope are 2 sets of matched eyepieces: B&L 7.5x and B&L 12.5x.

This instrument stands about 15 inches tall and it weighs 16 pounds – a relatively heavy vintage microscope. Included with this microscope is a very nicely fitted wood case with carrying handle. However, it is missing both a lock and key. Instead, a hook and staple is provided at the top of the case to secure the instrument when stored inside. This is the original B&L case for this instrument with a set of wood drawers attached to the top of the case door that are especially designed to accommodate optional additional objectives and the two sets of oculars. There is also a rack at the back of the case to accommodate the vertical illuminator. The microscope in its case + the accessories weigh in at 28 pounds.

STATEMENT OF CONDITION:

NOTE: The accompanying images are a part of this statement of condition. Please take the time to view all of the images so you can confirm the condition of the instrument and so you will know exactly what you will be getting should you prove to be the proud new owner of this very fine B&L vintage Micro-Interferometer Metallurgical Microscope.

In summary, this microscope is in very good to excellent condition cosmetically, mechanically and optically.

The black metal and nickel-plated brass parts of this microscope are in very good to excellent condition with virtually no evidence of any tarnish, corrosion or significant cosmetic imperfections.

The optics associated with this microscope are of very high quality. Both sets of eyepieces and the Interferometer objective lens are free of any optical defects and are cosmetically in very nice condition. The same goes for the other optical elements including the prism and glass reflector inside the vertical illuminator assembly (see close-up image of this unit). The optics associated with this instrument produce sharp, high contrast images. In fact, as noted above, this microscope can still be used for serious interferometric and metallurgical investigations to this day.

The plano-concave mirror is in excellent condition with no tarnish or spotting evident. One side of the green filter has some surface marks, but they do not interfere with its operation.

Mechanically, the coarse and fine focus mechanisms work flawlessly. The rack and pinion system that raises and lowers the stage works smoothly. The mechanical stage works smoothly in both the x & y directions.

The wood case that accompanies this instrument is in very good serviceable condition. However, as noted above, it lacks its lock and key. In lieu of the lock and key a hook and staple system keeps the case door closed when the microscope is stored inside. It is the original case that came with the instrument. Typically, though, it has some cosmetic surface scratches, dings and imperfections commensurate with its age.

Overall, this is a very nicely preserved example of a vintage Bausch & Lomb Micro-Interferometer Metallurgical Microscope. It is most certainly worthy of any vintage / antique microscope collection. And, should one choose to do so, it can still be used to this day for the serious examination and analysis of metals and minerals, as well as, for micro interferometry.

ABOUT BAUSCH & LOMB OPTICAL COMPANY:

The Bausch & Lomb Optical Company (now known as Bausch & Lomb, Incorporated - B&L, Inc. for short) is one of the oldest continuously operating companies in the United States today. Bausch & Lomb traces its roots to 1853, when John Jacob Bausch, a German immigrant, set up a tiny optical goods shop in Rochester, New York. That early shop sold eyeglasses, magnifiers, microscopes, and other products imported from Europe. Shortly thereafter, when he needed additional capital, he borrowed $60 from his good friend Henry Lomb and offered as security the promise that, if the business ever grew to such an extent that he needed a partner, Lomb would be brought in. The business did grow, and a uniquely American optical partnership was formed.

Early in the company’s history, Bausch made a discovery that led to eventual financial security for the business. Bausch found a piece of vulcanite rubber (a hard rubber used in hair combs) on the street. He discovered that it could be used to make eyeglass frames. Working on the stove in his tiny kitchen at home, Bausch perfected the molding of vulcanite rubber into eyeglass frames, which he fit with lenses imported from Europe and ground by hand in his small shop. In 1866, Bausch and Lomb started the Vulcanite Optical Instrument Co. The business began to market the unique frames, which proved to be more durable and less costly than the gold-filled metal or horn-rimmed frames on the market at the time. They also produced a line of magnifier frames.

By the end of 1866, the company was making a simple microscope. However, it was not until the year 1874 that their first compound microscope was produced. In that year, the company name was changed to Bausch & Lomb Optical Co. The following year, Ernst Gundlach came to work for Bausch & Lomb, designing a full product line of microscopes. His 1876 Patent that covered several improvements to the microscope was incorporated into most of these stands. Gundlach left the firm in 1878, after a long dispute, with the company retaining his several Patents.

Bausch's sons, Edward, William, and Henry all helped to fill the gap after Gundlach's departure. The company, of course, prospered and is alive and well today.

J.J. Bausch died in 1926 and Henry Lomb died in 1908.

BIDDING:

THE MONTANA LOGGER is very pleased to offer this very fine vintage Bausch & Lomb Micro-Interferometer Metallurgical Microscope with wood case and accessories with a very reasonable opening bid and with no reserve. Happy bidding!

NOTE: WE WARMLY WELCOME INTERNATIONAL BIDDERS/BUYERS. WE SHIP WORLDWIDE.

PAYMENT: Payment via PayPal is due within 3 days of the close of the auction.

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