Pappus wrote commentaries on Euclid's Elements and Data, and on Ptolemy's Almagestand Planispherium, but about all we know of these is through their influence onthe writing s of later commentators. Pappus' really great work is his Mathematical Collection, a combined commentary and guidebook of the existing geometrical works of his time, sown with numerous original propositions, improvements, extensions, and historical comments. Of the eight books the first, and part of the second, are lost.