Granville's egg

quartic

 last updated: 2005-10-23

W.A. Granville wrote in his calculus book 1) about this quartic egg.
Later (1947), R.A. Johnson wrote about this Granville's egg.

Some examples:

 

 

 

 

 

notes

1) Elements of the differential and integral calculus, Boston, Ginn & Co, 1929, p.380.

2) An ornithological note, American Mathematical Monthly 54 (1947), p. 594-595.