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Patent Model for Estimator Slide Rule Invented by Fredric Maurice Stapff
From the collection of National Museum of American History. Free to download, adapt and use — no permission needed.
About this work
In 1874 F. M. Stapff submitted this model to the U.S. Patent Office. He designed the instrument to calculate the volume of spaces shaped as prisms, such as embankments and ditches. It consists of a wooden base with two slides, one atop the other. The lower slide has pieces of paper pasted on both sides, containing various curves related to finding the equivalent heights of an embankment (e.g., the height of an embankment of the same volume having trapezoidal sides).
National Museum of American History’s own descriptionCredit linePatent Model for Estimator Slide Rule Invented by Fredric Maurice Stapff. 1874. National Museum of American History. CC0.
