Plaster Surface Model by Alexander Crum Brown, c 1900.

Plaster Surface Model by Alexander Crum Brown, c 1900.
Plaster model of the surface z = 3a(x2 - y2) - (x3 + y3). Alexander Crum Brown was both a mathematician and chemist. He was a prolific maker of mathematical models. In this example, every section made by a plane passing through the blue line forms an ellipse
 
Currently on display in:
Mathematics
Year made :
c.1900
Inventory number :
1910-136