Object ID:
2001.165
Title:
Model 4-B Circular Slide Rule
Description:
Black vinylite disc has raised numerals and braille notation, with further divisions represented by evenly spaced single dots and double dots. One side (the linear scale) has a single plastic pointer and the other side (the logarithmic scale) has two plastic pointers, fastened to the center of the disc by brass screws. A knurled nut allows the setting/adjustment of the pointers on the logarithmic scale. Includes 3 pages of typewritten instructions for "Model 4-B Circular Slide Rule" and a typewritten note.
Dimensions:
Dia-12 inches
Date:
ca. 1950
Made by:
American Foundation for the Blind
Place of Origin:
New York
Provenance:
Donor dates the slide rule to the 1930s, but AFB did not introduce their first disc slide rule until 1946.
Credit Line:
Gift of Visually Handicapped Services, Detroit Receiving Hospital
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Circular slide rule
Circular slide rule