Purser's Parabola
References
Casey, J. A Treatise on the Analytical Geometry of the Point, Line, Circle, and Conic Sections,
Containing an Account of Its Most Recent Extensions with Numerous Examples, 2nd rev.
enl. ed. Dublin: Hodges, Figgis, & Co., p. 220, 1893.Purser,
F. Quart. J. 8, 66, 1867.