"How Old Is That Microscope in the Window? By Herbert A. Gold"
"One of the first things a collector wants to know about his newly acquired prize is how old it is. Without the actual bill of sale or other reliable documentation it may be a difficult question to answer. There are many clues to age including configuration, materials of construction, provenance, signature and a serial number. Then there is the matter of the difference between when it was made and when it was sold. Serial numbers, when there are supporting records are a pretty good, albeit far less than perfect, indication of age. This article will be concerned with serial numbers found on stands of two American makers, Spencer and Bausch and Lomb, for which some reasonably authoritative documentation has been found.
Michael Benz of Benz Microscope Optics Center in Ann Arbor, MI is a third generation microscope dealer. He also happens to have a fine collection of microscopes and an overwhelming collection of microscopical literature. His family has represented Spencer and many other makers in their various incarnations over many years. Michael has been kind enough to share the following tabular material with us.
The Spencer Lens Company was acquired by American Optical in 1935. In 1962 AO formed a partnership with Reichert Scientific Instruments. Early in 1986 Reichert launched a sales promotion to find the earliest ìSpencerî microscope. The grand prize was a weekend trip to Paris on the Concorde with dinner at Maxim's. I don't know what microscope was the winner or who ate the goose livers but Michael does have a copy of the documentation that was used to determine the winner.
Reichert published two tables of serial numbers. The first table showed the serial number range and date range associated with nine different models. It has been published in Dr. Brian Bracegirdle's 1996, Notes on Modern Microscope Manufacturers, page 70. What I believe to be of more interest is the second table which is shown below.
On a B & L factory visit a number of years ago, Michael had the opportunity of going through their files and finding a copy of serial numbers and their date of manufacture. There is a note on the list indicating that these are approximate dates of manufacture and not necessarily dates of sale.
For Bausch & Lomb
Serial Year of
Number Manufacture 1 1876
150 1877 350 1878
Serial Year of
Number Manufacture
32000 1900
33000 1901
35000 1902
Serial Year of
Number Manufacture 170000 1924 175000 1924 180000 1925
800 1879
1100 1880 1450 1881 1750 1882 2000 1883 2500 1884 3000 1885 3800 1886 4500 1887 5300 1888 6375 1889 7600 1890 9200 1891
10000 1892 11700 1893 13900 1894 17000 1895 20000 1896 25000 1897 28000 1898 30000 1899
40000 1903
45000 1904 52000 1905 57000 1906 63000 1907 69000 1907 76000 1909 82000 1910 86000 1911 89000 1912 95000 1913 98000 1914
104000 1915 110000 1916 120000 1917 129000 1918 135000 1919 140000 1920 148000 1921 155000 1922 160000 1923
185000 1926 190000 1926 195000 1927 200000 1928 205000 1929 215000 1929 225000 1930 230000 1931 235000 1932 240000 1934 244000 1935 247000 1935 250000 1936 260000 1937 270000 1938 280000 1939 290000 1940 300000 1940 310000 1941 320000 1942."