Published 1898â€"1907, this three-part collection, edited by the Danish philologist Johan Ludvig Heiberg (1854â€"1928), contains the extant astronomical works in Greek of Ptolemy, active in second-century Alexandria. Volume 1 appeared in two parts. Part 2 (1903) contains Books 7-13 of Ptolemy's major astronomical treatise, the Almagest.