Model for Descriptive Geometry by A. Jullien - Angle between Two Planes with Parallel Horizontal Traces

The two planes are APA’ and BQB’, both perpendicular to the vertical plane. As can be seen in the relief, the horizontal images are the parallel lines PA and QB. Each red string represent a line on each plane that is perpendicular to intersection of the plane with the horizontal plane. These lines meet at (m, m’). The locus of all such intersection points is the horizontal line (wire) coming out of the vertical plane. By rotating (m, m’) about segment sm, the image of the angle of intersection of the planes is given by angle sM1n.
For more details, see COLL.1986.0885 and 1986.0885.01.01.
Currently not on view
date made
ca 1880
Jullien, A.
place made
France: Île-de-France, Paris
Physical Description
paper (overall material)
metal (overall material)
overall: 6.5 cm x 7.5 cm x 6.5 cm; 2 9/16 in x 2 15/16 in x 2 9/16 in
ID Number
catalog number
accession number
descriptive geometry
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Jullien Geometric Models
Data Source
National Museum of American History


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