edition of the Cyropaedia in 1618. Savile was keen to impart his understanding of mathematics to his students at Oxford, and in founding the Geometry chair he gave thirteen preparatory lectures on the original books of Euclid's Elements in 1620. These were published in 1621 as his Praelectiones tresdecim in principium elementorum Euclidis, Oxonii habitae MCDXX. Oxonii: Excudebant Iohannes Lichfield, & Iacobus Short, 1621. ('Thirteen introductory lectures on the beginning of the Elements of Euclid, held at Oxford in 1620'.) It was Savile who first traced the hand of Theon of Alexandria as a commentator on Euclid. The edition published in England, until then the only one containing all the extant works attributed to Euclid, was that of Dr David Gregory, published at Oxford in 1703, with the title, Εὐκλείδου τὰ σωζόμενα, Euclidis quae supersunt omnia. The parallel Greek text is that of the 1533 Basel edition by Simon Grynäus, corrected from Savile's 13th century Greek MSS. which Savile bequeathed to the Savilian Library, and from Savile's annotations in his own copy. The Latin translation, which accompanies the Greek on the same page, is for the most part that of Commandino. Collections In 1619, after founding two lectureships in geometry and astronomy, Savile donated a library to the university. It was a collection of mathematical works, including the related subjects of optics, harmonics, mechanics, cosmography, the applied sciences of surveying, navigation, and fortification, and a quantity of fine printed books, primarily from the 16th century. Nearly all of the seventeenth-century Savilian professors added to the library. Dr. Peter Turner (Geometry Chair, 1631-48) bequeathed Greek manuscripts, John Greaves (Astronomy Chair, 1643-9) added some of his own papers. Part of the Savilian library might also have come from Dr. Seth Ward (Astronomy Chair, 1649-61) sometime after 1682. It was Sir Christopher Wren (Astronomy, 1661-1673), however, who gave the first extensive contribution to the library, leaving his astronomy and geometry books to it when he retired from the Chair. A catalogue of the Savile library appeared in Dr. Edward Bernard's (Astronomy chair, 1673-91) Catalogi Librorum Manuscriptorum Angliae and Hiberniae. Dr. John Wallis (Savilian professor, 1649-1704) gave the Savilian library 'the largest of its accretions', and many more were provided after his death in 1703. In the eighteenth century, not much more was added to Savile's collection, but later Stephen Rigaud (Geometry Chair, 1810-27; Astronomy, 1827-39) catalogued and contributed to it further. Rigaud died