In 1710, Newton found 72 of the 78 "species" of cubic curves and categorised them into four types. In 1717, and probably with Newton's help, James Stirling proved that every cubic was one of these four types. Newton also claimed that the four types could be obtained by plane projection from one of them, and this was proved in 1731, four years after his death.Conics and Cubics, Robert Bix. Undergraduate Texts in Mathematics, 2nd ed., 2006, Springer Verlag.
In 1710, Newton found 72 of the 78 "species" of cubic curves and categorised them into four types. In 1717 and probably with Newton's, help, James Stirling pro,ved that every cubic. was one of these four types. Newton also claimed that the four types could be obtained by plane projection from one of them and this was proved in 1731, four years after his deathConics and Cubics, Robert Bix. Undergraduate Texts in Mathematics, 2nd ed., 2006, Springer Verlag.