“Geometry is knowledge of the eternally existent.”
Pythagoras. ca.560-ca.480 BC. Greek philosopher and mathematician
This amazing unfolding sphere, or dissected sphere, is an American mathematical demonstration tool used as a teaching aid. While there were numerous European manufacturers of mathematical models, American manufacturers were much less common. This example by Albert H. Kennedy (1848-1940) of Rockport, Indiana is one of the few made in America and the only manufacture who used leather to join the moving segments. Kennedy became superintendent of the Rockport schools in 1878 and produced wood mathematical instructional models for high school teachers in the 1920s. This example is one of four different models Kennedy produced, and by far the most interesting.
While European mathematical models were generally more complicated and made mainly for viewing the American examples, as typified by the Albert H. Kennedy and the more famous W. W. Ross (1834-1906) examples, were made of wood and meant to be handled and manipulated by the students.
