A

David

Darling

lituus

The lituus is a spiral curve that was discovered by the English mathematician Roger Cotes (1682–1716) and named by the Scottish mathematician Colin Maclaurin in 1722. The Latin lituus refers to a staff shaped like a bishop's crosier. The lituus is the locus of a point that moves in such a manner that the area of a circular sector remains constant. The equation of the curve in polar coordinates is

 

    r 2 = a2/π