Ruled Surface with Chrome Frame, Curve of Intersection Indicated

Ruled Surface with Chrome Frame, Curve of Intersection Indicated

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This ruled surface has a chrome frame that bends to the right and to the left. On the top and the bottom are opposite parabolic pieces that are joined by yellow threads. On two opposite sides, the frame has cusp-like segments, which are joined by blue threads. The two other sides have identical opposite curves, which are joined by red threads. A piece of pink yarn marks the curve of intersection of these surfaces.
This is one of eight models of rules surfaces having a chrome frame given to the Smithsonian by Brown University (see MA.304722.35 through MA.304722.42). All these models are unsigned. Models of this general appearance were shown by Saul Pollock of Indiana State Teacher’s College in Terre Haute, Indiana, at the Century of Progress world’s fair, held in Chicago in 1934. A. Harry Wheeler, a mathematics teacher and maker of geometric models, visited the fair and noted Pollock’s models. Wheeler also communicated with mathematicians at Brown, and exhibited some of his models there. The models might be by Pollock, they might be copies by Wheeler.
Century of Progress, Official Handbook of Exhibits in the Division of the Basic Sciences Hall of Science, Chicago, 1934, p. 39-40, 43.
P.A. Kidwell, “American Mathematics Viewed Objectively: The Case of Geometric Models,” Vita Mathematica, ed. Ronald Calinger, Washington, DC: Mathematical Association of America, 1996, pp. 197-207.
Currently not on view
Object Name
Geometric Model
geometric model
date made
ca 1934
Physical Description
chrome (overall material)
thread (overall material)
overall: 31 cm x 21 cm x 16.6 cm; 12 7/32 in x 8 9/32 in x 6 17/32 in
ID Number
catalog number
accession number
Credit Line
Gift of Brown University Department of Mathematics
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Data Source
National Museum of American History
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