Model by Philip Malmberg, a Student of A.H. Wheeler, Cylinder Transformable into a Hyperboloid of One Sheet

Joining points along the radius of two circles generates a family of straight lines. If the circles are at their maximum separation, the lines form a cylinder. When rotated, the circles approach and the surface becomes a hyperboloid of one sheet. Further rotation (not possible on this model) yields a double cone.
String models with elegant brass frames sold for engineering and mathematics education sold from the nineteenth century (see 1985.0112.009). Philip Malmberg, a high school student of A. Harry Wheeler, made this inexpensive version of the surface. He used disks cut from a cardboard box, leftover spools from thread, a wooden dowel, a bit of wire, and thread. Census records indicate that Malmberg went on to work as a draftsman.
For a photograph of Malmberg, see 1979.0102.308.
Currently not on view
Object Name
geometric model
date made
associated dates
teacher of maker
Wheeler, Albert Harry
Malmberg, Philip
Physical Description
paper (discs material)
wood (spools, dowel material)
thread (surface material)
wire (spring material)
white (overall color)
brown (overall color)
cut and glued (overall production method/technique)
average spatial: 11 cm x 7.8 cm x 7.8 cm; 4 11/32 in x 3 1/16 in x 3 1/16 in
place made
United States: Massachusetts, Worcester
ID Number
accession number
catalog number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Mathematical Association of America Objects
Data Source
National Museum of American History, Kenneth E. Behring Center


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