Model of a Cylindroid by Richard P. Baker, Baker #83 (a Ruled Surface)


This string model was constructed by Richard P. Baker, possibly before 1905 when he joined the mathematics faculty at the University of Iowa. Baker believed that models were essential for the teaching of many parts of mathematics and physics, and over one hundred of his models are in the museum collections. Baker mentioned the model in a 1905 listing of one hundred models he had constructed as well as in a 1931 catalog.

A typed paper label on the top of the wooden base of this model reads: No. 83 (/) CYLINDROID.

Like several other models Baker made, this shows a ruled surface, also called a scroll. Such a surface is swept out by a moving line. This line is represented by the blue string in the model. The string rotates periodically about the vertical access, and at the same time moves uniformly up (or down) the vertical axis. The surface also is known as Plücker’s conoid after the German mathematician and physicist Julius Plücker.


R. P. Baker, A List of Mathematical Models, [1905], p. 13.

R. P. Baker, Mathematical Models, Iowa City, Iowa, 1931, p. 72.

Date Made: ca 1900-1935

Maker: Baker, Richard P.

Location: Currently not on view

Place Made: United States

Subject: Mathematics


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


Exhibition Location:

Credit Line: Gift of Frances E. Baker

Data Source: National Museum of American History

Id Number: MA.211257.009Accession Number: 211257Catalog Number: 211257.009

Object Name: geometric model

Physical Description: thread (overall material)wood (overall material)metal (overall material)blue (overall color)black (overall color)screwed and threaded (overall production method/technique)Measurements: average spatial: 19.7 cm x 17.3 cm x 16.9 cm; 7 3/4 in x 6 13/16 in x 6 21/32 in


Record Id: nmah_1079786

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