Model of the Differential Geometry of a Helix by Richard P. Baker, Baker #89 (a Ruled Surface)
date: label: date made
content: ca 1900-1935
name: label: maker
content: Baker, Richard P.
notes: label: Description
content: 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.
label: Description
content: The typed part of a paper label on the top of the wooden base of this model reads: No. 89 (/) Diff. Geometry of a helix. The model illustrates several terms used to describe curves in three-dimensional space, using as an example the spiral curve on a cylinder known as a helix. In the model, the cylinder is represented by blue threads and the helix by a wire that twists along it. The point of interest, hereafter called P, is at the center, atop a wire extending perpendicularly from the base (the normal to the helix at the point). Shown with red threads is the osculating (kissing) plane to the helix at P. The red thread that passes through P represents the tangent line at P. The wire circular arc passing through P in the osculating plane represents part of what is called the osculating circle. The smaller circles joined by wires that pass through P form what is called the osculating cone.
label: Description
content: Shown with yellow threads is a plane perpendicular to the osculating plane known as the normal plane. The thread on this plane that passes through P is called the binormal to the curve at P.
label: Description
content: The model sold for $7.50.
label: Description
content: References:
label: Description
content: R. P. Baker, <I>A List of Mathematical Models</I>, [1905], p. 16.
label: Description
content: R. P. Baker, <I>Mathematical Models</I>, Iowa City, Iowa, 1931, p. 12.
label: Description
content: R. P. Baker Papers, University of Iowa, Iowa City, Iowa.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Frances E. Baker
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.211257.012
label: accession number
content: 211257
label: catalog number
content: 211257.012
objectType: label: Object Name
content: geometric model
physicalDescription: label: Physical Description
content: thread (overall material)
label: Physical Description
content: wood (overall material)
label: Physical Description
content: metal (overall material)
label: Physical Description
content: black (overall color)
label: Physical Description
content: yellow (overall color)
label: Physical Description
content: red (overall color)
label: Physical Description
content: blue (overall color)
label: Physical Description
content: screwed, soldered & threaded (overall production method/technique)
label: Measurements
content: average spatial: 14.2 cm x 25.6 cm x 17.9 cm; 5 19/32 in x 10 3/32 in x 7 1/16 in