In March 1856, the University of Michigan named a committee “to contract for the construction of a suitable microscope for the University.” Within a year or so, this committee had spent $469 for a microscope made by Charles Achilles Spencer, America’s first successful microscope maker. This enormous sum was charged to the account of "Natural History" and the microscope was placed in the hands of Alexander Winchell, a professor of geology who would soon be named Geologist of the State. Twenty years later, after Winchell had left the University, the costly microscope was transferred to the Physiological Laboratory in the Medical School. The transfer was arranged by Charles Stowell, a young doctor who would spend his career teaching physiology and microscopy, and who was clearly aware of the historic importance of the instrument. In an obituary notice penned shortly after Spencer’s death in 1881, Stowell explained that the objective was a 1/16 of “as near 180°as can be obtained.” That is, it had a very short focal length and a very wide angular aperture. When Stowell got his hands on this objective, he saw a crack “running across about 1/3 of the field,” and so returned it to the firm. Spencer replied that he could make a new objective nearly as cheap as he could remedy this, “for it is one of my first glasses.” Accepting the inevitable, Stowell ordered a new 1/18. We have not yet measure the objective, but note that it does not appear to have a crack.
Spencer referred to the stand of this microscope as a Pritchard, recognizing that the form had been popularized by Andrew Pritchard, an important London naturalist and optician. The “C. A. & H. Spencer / Canastota, N.Y.” inscription on the tube refers to the partnership between Charles A. Spencer and his cousin Hamilton, a partnership that began around 1848 and ended around 1854.
Currently not on view
Object Name
date made
associated dates
C. A. & H. Spencer
Physical Description
brass (overall material)
glass (overall material)
overall: 16 7/8 in x 13 in x 8 in; 42.8625 cm x 33.02 cm x 20.32 cm
place made
United States: New York, Canastota
ID Number
catalog number
accession number
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Medicine and Science: Medicine
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Data Source
National Museum of American History, Kenneth E. Behring Center


"Is one of the sets of dimensions for a case?The objective looks like a 1-1/2 inch by either Smith and Beck or R. and J. Beck of London, not a Charles Spencer product. If purchased in 1856 the microscope would have been made with Spencer's bayonet mounting system for the objectives. The Beck lens would have a screw thread for mounting. I believe this lens has been forcibly screwed into the bayonet socket.Speaking of Spencer microscopes, I see no mention in the search results of the C. A. Spencer and Sons for Geneva Optical Works mentioned in the journal Rittenhouse, vol. 2, No. 3, 1988, page 77."
We need a microscope expert to examine the stand and the lens.

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