The idea of specific gravity appears all through, though this actual term is not used. Archimedes speaks of the solid being lighter or heavier than the fluid or equally heavy with it, or when a ratio has to be expressed, he speaks of a solid the weight of which (for an equal volume) has a certain ratio to that of the fluid. BIBLIOGRAPHY. The _editio princeps_ of the works of Archimedes with the commentaries of Eutocius was brought out by Hervagius (Herwagen) at Basel in 1544. D. Rivault (Paris, 1615) gave the enunciations in Greek and the proofs in Latin somewhat retouched. The _Arenarius_ (_Sandreckoner_) and the _Dimensio circuli_ with Eutocius's commentary were edited with Latin translation and notes by Wallis in 1678 (Oxford). Torelli's monumental edition (Oxford, 1792) of the Greek text of the complete works and of the commentaries of Eutocius, with a new Latin translation, remained the standard text until recent years; it is now superseded by the definitive text with Latin translation of the complete works, Eutocius's commentaries, the fragments, scholia, etc., edited by Heiberg in three volumes (Teubner, Leipzig, first edition, 1880-1; second edition, including the newly discovered _Method_, etc., 1910-15). Of translations the following may be mentioned. The Aldine edition of 1558, 4to, contains the Latin translation by Commandinus of the _Measurement of a Circle_, _On Spirals_, _Quadrature of the Parabola_, _On Conoids and Spheroids_, _The Sandreckoner_. Isaac Barrow's version was contained in _Opera Archimedis_, _Apollonii Pergoei conicorum libri_, _Theodosii Sphoerica_, _methodo novo illustrata et demonstrata_ (London, 1675). The first French version of the works was by Peyrard in two volumes (second edition, 1808). A valuable German translation, with notes, by E. Nizze, was published at Stralsund in 1824. There is a complete edition in modern notation by T. L. Heath (_The Works of Archimedes_, Cambridge, 1897, supplemented by _The Method of Archimedes_, Cambridge, 1912). CHRONOLOGY. (APPROXIMATE IN SOME CASES.) B.C. 624-547 Thales 572-497 Pythagoras 500-428 Anaxagoras 470-400 / Hippocrates of Chios \ Hippias of Elis 470-380 Democritus 460-385 Theodorus of Cyrene 430-360 Archytas of Taras (Tarentum) 427-347 Plato 415-369 Theaetetus 408-355 Eudoxus of Cnidos / Leon fl. about 350 < Menaechmus | Dinostratus \ Theudius fl. 300 Euclid 310-230 Aristarchus of Samos 287-212 Archimedes 284-203 Eratosthenes 265-190 Apollonius of Perga