The Greek astronomer and geometrician Apollonius of Perga (c.262–c.190 BCE) produced pioneering written work on conic sections in which he demonstrated mathematically the generation of curves and their fundamental properties. His innovative terminology gave us the terms 'ellipse', 'hyperbola' and 'parabola'. The Danish scholar Johan Ludvig Heiberg (1854–1928), a professor of classical philology at the University of Copenhagen, prepared important editions of works by Euclid, Archimedes and Ptolemy, among others. Published between 1891 and 1893, this two-volume work contains the definitive Greek text of the first four books of Apollonius' treatise together with a facing-page Latin translation. (The fifth, sixth and seventh books survive only in Arabic translation, while the eighth is lost entirely.) Volume 2 contains the fourth book in addition to other Greek fragments and ancient commentaries, notably that of Eutocius, as well as the editor's Latin prolegomena comparing the various manuscript sources.