L. Brill No. 163, Ser.13 No. 1, Ruled Surface with Two Real Double Lines and Four Pinch Points on Each of the Lines
date: label: date made
content: 1892
name: label: maker
content: L. Brill
notes: label: Description
content: The German Karl Rohn (1855-1920) intended to become an engineer, but found the mathematical part of his studies at the polytechnic in Darmstadt more intriguing. He studied mathematics with Alexander von Brill and Felix Klein in Munich, and went on to a career as a professor of mathematics in Leipzig and Dresden.
label: Description
content: In 1886 and again in 1892, Rohn published sets of string models with the publisher and mathematical model distributor Ludwig Brill. Several models from the first set, Brill’s Series XIII, were exhibited at the Columbian Exposition, a world’s fair held in Chicago in 1893. This is one of them, number 1 in the series.
label: Description
content: The thread model has a metal frame. It shows two congruent ruled surfaces (in gold), as well as two double lines (in red). Each of the lines has four pinch points, that is to say points for which every neighborhood is self-intersecting.
label: Description
content: The model was received at the Smithsonian with its threads broken and restrung.
label: Description
content: References:
label: Description
content: L. Brill, <I>Catalog mathematischer Modelle. . .</I>, Darmstadt: L. Brill,1892, pp. 27-28, 68.
label: Description
content: “Mathematical Models of Surfaces”, University of Groningen, website accessed October 16, 2017. This site describes the mathematics of these surfaces in more detail. It illustrates them with examples of the models published by Brill’s successor, Martin Schilling.
label: Location
content: Currently not on view
place: label: place made
content: Germany: Hesse, Darmstadt
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 Wesleyan University
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1985.0112.134
label: catalog number
content: 1985.0112.134
label: accession number
content: 1985.0112
objectType: label: Object Name
content: Geometric Model
label: Object Name
content: geometric model
physicalDescription: label: Physical Description
content: string (overall material)
label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: 18.5 cm x 25 cm x 12.2 cm; 7 9/32 in x 9 27/32 in x 4 13/16 in