J. Zentmayer, Maker, Philadelphia, Patented 1876, No. 1343

The American Centennial model microscope

 

J. Zentmayer, Maker, Philadelphia, Pat. 1876, No. 1343. The American Centennial model microscope

Zentmayer American Centennial Microscope

J. Zentmayer, Maker, Philadelphia, Pat. 1876, No. 1343. The American Centennial model microscope

J. Zentmayer, Maker, Philadelphia, Pat. 1876, No. 1343. The American Centennial model microscope

American Centennial microscope stage

American Centennial microscope accessories

    Accessories include three objectives, five eyepieces (two pairs for use as a binocular), diaphragm wheel, condenser with diaphragm wheel, analyzer, polarizer, objective-mounted side reflector, stage forceps, live-box, compressor, and additional filters and fittings.

    J. Zentmayer's American Centennial microscope

The American Centennial microscope swinging substage

 

 

 

 

Zentmayer 1876 patent

    The Aug. 15, 1876 patent describes the fine adustment mechanism and a novel swinging substage which allows extreme oblique illumination and which was very influential for the further development of the microscope during the latter part of the 19th century. For example, see the Ross-Zentmayer Student Model elsewhere on this website.

American Centennial Zentmayer microscope

The American Centennial model was first exhibited by Joseph Zentmayer (1826-1888) at the Centennial Exposition in Philadelphia in 1876. The example shown here was made shortly after this date. As quoted by S. H. Gage in Microscopy in America (1830-1945), 1964 in a letter dated 1938 from Arthur H. Thomas (a Philadelphia instrument supplier) to H. N. Ott of the Spencer Lens Co. in reference to the binocular version of this microscope, it was stated that "there were forty-four of these instruments made in all, and they are now museum items".
Another later example of this model with serial number 2594 is also represented in this collection. It differs from the example on this page by having a centering mechanism for the sub-stage.

The American Centennial model is considered by many the finest American microscope manufactured in the 19th century. Prior to the introduction of the American Centennial, the Grand American model was the top-of-the-line microscope produced by the firm. Another later example of this model with serial number 2504 is represented in this collection. It differs from the one shown on this page in having a more elaborate centering sub-stage.

See the article written by Zentmayer entitled "What I Know About Late Improvements of the Microscope" published in the  Journal of the Franklin Institute, LXXXIV, 1877.

An 1880 Zentmayer advertisement:

An 1880 Zentmayer advertisement.JOSEPH ZENTMA YER, OPTICIAlII'. No. 141 South Fourth Street, Philadelphia. MICROSCOPES MICROSCOPICAL ACCESSORIES. Microscopes from $50 to $1000. WM. WALES, S61 West 34th Street.

1876 Centennial medal awarded to Joseph Zentmayer

Biographical Sketch of Joseph Zentmayer

See this article from: Proceedings of the American Microscopical Society. Vol. 14, No. 3, 1893.

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