This small, flat unpainted wooden pear wood curve has a hyperbolic top edge and a straight bottom. There are two holes along the axis. A mark on one side reads: 2182. Another mark on the same side reads; KEUFFEL & ESSER (/) N.Y.
Keuffel & Esser’s model 2182 was a set of pear wood curves of hyperbolas in eight sizes, ranging from 2 to 5 1/2 inches in depth. This is the 3 ½ inch size. Keuffel and Esser sold ellipses, hyperbolas and parabolas made from pear wood from at least 1892 until at least 1913. By 1921, such curves were available from K & E only in xylonite.
References:
Keuffel & Esser Company, Catalog, New York, 1892, p. 151.
Keuffel & Esser Company, Catalog, New York, 1909, p. 226.
Keuffel & Esser Company, Catalog, New York, 1913, p. 203.
Keuffel & Esser Company, Catalog, New York, 1921, p. 147.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.