CASED VINTAGE BRASS BAUSCH & LOMB MDL APS PORTABLE TRAVELING MICROSCOPE - 1926. The instrument also bears Serial Number 186425, which is engraved on the side of the brass ocular holder on the top of the body tube (see image).
In addition, the instrument bears the Patent Date Jan. 5, 1915 at the top of the limb.
This date refers to US Patent Number 1,123,583 that was granted to W. Patterson and assigned to B&L for the fine focus adjustment mechanism found on this instrument. NOTE: A copy of this Patent will be provided with the instrument. B&L made at least two (2) portable microscope models.The first was their model BHP which included both a folding stage and foot. It was featured in their 1911 Catalog of Microscope and Accessories on pages 36 and 37. It was evidently modeled after a very similar portable microscope made by E. Leitz Wetzlar that was introduced in 1899 and improved in 1905. B&L introduced a smaller and less complex model, the APS, in their 1922 Catalog of Microscopes and Microtomes and it is the model featured here. It included a folding foot, but with a fixed stage. B&L offered several variants of the Model APS either with a double or triple revolving nosepiece and with or without a screw mounted Abbe condenser in the substage.
Included with this listing is a cut from the 1922 Catalog that shows one version of this latter instrument that has the screw mounted Abbe condenser in the substage. The unit featured here lacks that feature, but has an iris diaphragm and so is one of the more simplified versions of the Model APS.This Bausch & Lomb Model APS Portable Microscope along with its original wood case and complimentary accessories will be a very nice addition to any microscope collection, especially one that features the very innovative B&L optical instruments. In fact, this is the first of this model that I have seen in all my years of collecting antique and vintage microscopes. Perhaps not very many were manufactured. DETAILED DESCRIPTION: This microscope is built upon folding V shaped folding base when in the open position.
In the folded position, the two legs of the base pivot and come together to form a rectangular block that allows the instrument to be nicely nested into its wood case. Rising from the base is a nicely sculpted fixed vertical arm or limb that supports the stage and the rest of the instrument. This instrument is equipped with a 92mm by 76mm rectangular Vulcanite covered fixed stage. The stage has a 15 mm central aperture and includes a pair of removable slide clips atop the stage.Under the central aperture and built into the underside of the stage is an iris diaphragm with filter holder underneath. The size of the diaphragm opening is controlled by a lever that is used to move the diaphragm to a desired aperture. Included with the microscope is a blue filter and two (2) dark field aperture stops that are inserted into the filter holder under the diaphragm.
Completing the substage illumination system is 50mm plano-concave yoke mounted mirror on a swinging arm that allows for oblique illumination. Coarse focus is by a rack and pinion assembly at the leading edge of the limb. A pair of nicely machined extra-large 40mm diameter brass milled heads controls the coarse focus. Fine focus is by means of pair brass micrometer knobs mounted on the side of the limb below and behind the coarse focus knobs.
The fine focus mechanism is very precise in concert with the 1915 US Patent description. The body tube of the microscope is equipped with a drawtube that is marked with a millimeter scale. At the top of the drawtube is a brass ocular holder. Two (2) B&L eyepieces are included with the instrument one marked 5x and the other 10x. When not in use on the microscope, the eyepieces are stored in dedicated slots within the wood case.The lower end of the optical tube is equipped with a triple revolving objective holder or nosepiece equipped with the following objective lenses: A B&L Divisible 16mm 0.5 N. 10x low power objective, a B&L Uncovered 4mm 0.65 N. Medium power objective, a Reichert Austria Number 7a 60x medium high power objective and a Bausch & Lomb 1.9 mm 1.30 N. Oil Immersion high power objective. The objectives provided cover a nice range of magnifications.
Each of the objectives comes in an appropriately marked brass canister for storage of the objectives in the case. When not in use on the microscope the objectives in their brass canisters are stored in dedicated slots in the wood case.When this microscope is set up for observations with the drawtube raised to the highest level, it stands about 13.5 inches tall. When prepared for nesting in its wood case, the microscope stands about 9.5 inches tall.
This instrument weighs about 7 pounds. Accompanying the microscope is a very nice horizontal hard wood case with a black metal carrying handle and a combination sliding catch and lock mechanism, but the key to the lock is missing. This is the original wood case for this instrument.The outside of the case also has a pair of fancy hooks and pins that keep the case securely closed during transport. The interior of the case contains slots or receptacles for the loose components that come with the instrument. The exterior dimensions of the case are 10.75 inches long, 6.5 inches wide and 3.75 inches deep. The microscope and accessories in the wood case weigh in at about 10 pounds making for a very portable instrument for use in field investigations.
STATEMENT OF CONDITION: NOTE: The accompanying images are a part of this statement of condition. Please take the time to view each of the images captured under natural light so you can confirm the condition of the instrument and to see what you will be getting should you be the very fortunate new owner of this fine B&L Model APS Portable Microscope.
The condition of this microscope is deemed to be very good to excellent for its age (now some 92 years old and counting). The overall finish on this microscope consists of a black lacquered foot, pillar and body tube with the rest of the instrument consisting of lacquered brass. The brass parts are in excellent condition with no tarnish present. I would estimate the original lacquer retention on the brass at near 100%. As the accompanying images will attest, the brass on this microscope has a nice deep honey gold patina.
This instrument was evidently very well cared for over the years. NOTE: The only treatment we have given this microscope is to clean it of dust with dilute Windex and then to give the brass parts a coat of Renaissance Wax from THE GEMMARY to preserve it from further tarnish. We make it a firm practice not to deep clean and polish antique/vintage brass microscopes.The eyepieces and the objective lenses are in very good condition with no defects evident. The optics in this microscope combine to provide very nice well resolved images of prepared antique microscope slides. The plano-concave mirror is in very good condition with no tarnish or loss of silvering. Both the coarse and fine focusing mechanisms on this microscope work firmly and precisely. The iris diaphragm under the stage works properly.
The hardwood case that accompanies this instrument is in relatively good serviceable condition. However, as noted above, the lock mechanism is missing its key the case and key having parted ways in the past. As is typical of cases from this period, it has the customary minor surface dings, surface scratches and minor age splits in the wood associated with use over the years.
The protective felt pads inside the case are slightly eroded with age. In summary, as the accompanying images will attest, this portable microscope is very well preserved for its age and is still fully functional as a travelling microscope after over 90 years of age. In fact it is still quite capable of meeting the needs of the discriminating microscopist for use in the field or on a trip away from ones laboratory.It will make a handsome addition to any antique microscope collection, especially one with an emphasis on precision made specialty instruments. We will also consider reasonable offers for this instrument. BEST OFFERS: Please submit your best offers as early as possible during the listing period. This is due to the fact that we consider each best offer on its own merits.
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The item "CASED VINTAGE BRASS BAUSCH & LOMB MDL APS PORTABLE TRAVELING MICROSCOPE 1926" is in sale since Friday, March 23, 2018. This item is in the category "Collectibles\Science & Medicine (1930-Now)\Scientific Instruments\Microscopes, Lab Equipment". The seller is "mtloggera" and is located in Hamilton, Montana.
This item can be shipped worldwide.