Geometric Model, Ruled Surface Adjustable from Cylinder to Hyperboloid of One Sheet to Double Cone


This adjustable string model has a metal base painted black that supports two brass discs on a central spindle. A circle of holes is near the rim of both discs. The gold threads that join these holes form a cylinder. A screw below the lower disc holds a metal sleeve that in turn holds up the disc. Releasing this screw and twisting the lower disc generates a hyperboloid of one sheet. Raising the sleeve and securing the screw holds the model in this position.

The model is unsigned.

Compare 1982.0795.30. Also compare Brill model 1985.0112.009, in which weights are used in place of a mechanism. The Brill model shows other surfaces as well.

Location: Currently not on view

Subject: Mathematics


See more items in: Medicine and Science: Mathematics, Science & Mathematics


Exhibition Location:

Credit Line: Gift of the Department of Mathematics, The University of Michigan

Data Source: National Museum of American History

Id Number: 1982.0795.29Catalog Number: 1982.0795.29Accession Number: 1982.0795

Object Name: Geometric Model

Physical Description: string (overall material)brass (overall material)Measurements: overall: 43.5 cm x 23.5 cm x 23.5 cm; 17 1/8 in x 9 1/4 in x 9 1/4 in


Record Id: nmah_1213978

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.