Geometric Models, L. Brill No. 96. Ser. 3 No. 4, Two Ellipsoids with One Stand

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In the nineteenth and early twentieth century, students studying technical subjects often learned about the representation of surfaces by equations in courses in solid analytic geometry. Schools in Europe, the United States, and Japan sometimes purchased models to illustrate such surfaces. These objects are part of series of models of quadric surfaces (surfaces of degree two) designed in 1878 by Rudolf Diesel, then a student at the technical high school in Munich. They were published by the firm of Ludwig Brill in Darmstadt. These examples were exhibited at the German Educational Exhibit at the Columbian Exposition held in Chicago in 1893, and then purchased by Wesleyan University.
The ellipsoid shown can be represented by the equation: x2/a2 + y2/ b2 + z2/c2 = 1. Sections parallel to any of the axes are ellipses. A grid of perpendicular lines of curvature is shown on the models. A paper tag on one models reads: 96. Paper tags on both of them read: Ellipsoid. (/) Verl. v. L. Brill. 3. Ser. Nr. 4. The models fit on an elliptical wooden stand painted black (only one stand survives). A mark in pencil on the bottom of the stand reads: III.IV.
These two models are larger than the ellipsoid with catalog number 1985.0112.068, but the same lines of curvature are shown.
Ludwig Brill, Catalog mathematischer Modelle. . ., Darmstadt: L. Brill, 1892, p. 7, 75-76, 91.
Henry Burchard Fine and Henry Dallas Thompson, Coordinate Geometry, New York: Macmillan Company, 1931, pp. 237-239.
Gerard Fischer, Mathematical Models, Braunschweig / Wiesbaden: Friedr. Vieweg & Sohn, 1986, vol. I, p. 60, vol. II, pp.25-28.
Currently not on view
date made
L. Brill
place made
Deutschland: Hessen, Darmstadt
Physical Description
paper (overall material)
wood (overall material)
plaster (overall material)
each: 10.8 cm x 18 cm x 15 cm; 4 1/4 in x 7 3/32 in x 5 29/32 in
ID Number
catalog number
accession number
Credit Line
Gift of Wesleyan University
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Data Source
National Museum of American History


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