Books in the Claudii Ptolemaei opera quae exstant omnia 2 Volume Set series

Published 1898-1907, this three-part collection, edited by the Danish philologist Johan Ludvig Heiberg (1854-1928), contains the extant astronomical works in Greek of Ptolemy, active in second-century Alexandria. Volume 1 appeared in two parts. Part 1 (1898) contains Books 1-6 of Ptolemy's major astronomical treatise, the Almagest.