the contrary, Philon, and therefore the rest, must have lived after the time of Archimedes, as we learn from Tzetzes (Chil. 2.5.152) that Philon, in one of his works, mentions Archimedes.
There is no reason, therefore, why we should reject the express statement of Athenaeus (iv. p. 174c.), where he mentions Ctesibius as flourishing in the time of the second Euergetes, Ptolemy Physcon, who began to reign B. C. 146. Fabricius, with odd inconsistency, places the era of Philon at A. U. C. 601=B. C. 153, which is sufficiently correct. Consequently Heron must be placed latcer. (See Schweighäuser, ad Athenaeum, vol. vii. p. 637, &c.; Clinton, F. H. vol. iii. p. 535.) All that we know of his history is derived from his own notices in the work to be mentioned immediately ; that he had been at Alexandria and Rhodes, and had profited by his intercourse with the engineers of both places (pp. 51, 80, 84).
Among his works is one wherein he took a wide range, treating of the formation of h