Protractor.
Description:
Patent for a new and improved protractor. This design "is to make a protractor or plotter by which may be calculated the length of the base, perpendicular, and hypotenuse of a right-angled triangle where the latitude and departure or the altitude and depression are given" (lines 15-20). To this end, it consists, "with the semicircular protractor provided with a rectangular opening the edges of which are graduated, and centrally-pivoted vernier, of the departure-scale arranged to move up or down…
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Date:
June 10, 1890
Creator:
Dolman, John H.
Item Type:
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Patent
Partner:
UNT Libraries Government Documents Department