Bonnie Madison Stewart (July 10, 1914 – April 15, 1994)[1] was a professor of mathematics at Michigan State University from 1940 to 1980.
[2] He earned his Ph.D. from the University of Wisconsin–Madison in 1941, under the supervision of Cyrus Colton MacDuffee.
[4] Stewart's contributions to number theory also include a complete characterization of the practical numbers in terms of their factorizations, which he published in 1954, a year before Wacław Sierpiński's independent discovery of the same result.
A study of orientable polyhedra with regular faces, in which he discussed what are now called Stewart toroids.
The first three categories are all convex, whereas Stewart toroids have polygonal-faced tunnels.