Wren’s scientific equipment was primarily that of a mathematician, and to this he added an inventive turn of mind, which developed first in the construction of apparatus and was afterwards so nobly turned to account in his building. As a man of science he touched everything and adorned it, but he cannot be regarded as a supreme pioneer in any particular direction, nor is his name associated with any fundamental discovery. As mathematician he was abreast of all the knowledge of the day; he contributed to the advancement of knowledge therein as in his discussions of the cycloid, but even in that particular subject his work lacks the luminous intuition displayed by Pascal. Nor did he break fresh ground and conceive new methods which afterwards developed into part of the fundamental texture of mathematics, as Wallis did with his theory of infinitesimals, or as Newton did a few years later in a larger field. Wren’s activity at the Royal Society in the multifarious problems which its members examined must not be allowed to obscure the fact that, _professionally_, he was an astronomer. Gresham Professor at twenty-five, and Savilian Professor at twenty-eight, he achieved little that has survived. The world and his own nimble mind called him to an excess of enterprises. In 1662, his indulgent friend Sprat wrote, “The Vice-Chancellor [of Oxford University] did yesterday send for me to enquire where the _Astronomy Professor_ was, and the reason of his absence so long after the beginning of term.... _He most terribly told me that he took it very ill_ you had not all this while given him any account of what hindered you in the discharge of your office.” Sprat stoutly defended Wren and urged on the angry Vice-Chancellor that the rebuilding of St. Paul’s and the fortifying of Tangier (Wren toyed with the latter but refused it) were of greater “concernment for the benefit of Christendom” than “the drawing of lines in Sir Harry Savill’s school.” It was not until 1673, however, that Wren officially turned his back on astronomy by resigning the Savilian professorship. The chief document of his astronomical career is his inaugural Gresham lecture in 1657, of which Latin and English versions are printed in _Parentalia_. A manuscript lecture, _De corpore Saturni ejusque phasibus Hypothesis_, flits irritatingly by us as having been possessed by one William Jones, Esquire, but after that--silence. The Gresham oration was a little pompous and for the “politer genii” whom he espied in his audience.