His health in his early years was extremely delicate. On this account he received the commencement of his education at home under the superintendence of his father and a domestic tutor. He was then sent to Westminster School, over which the celebrated Busby had just come to preside. The only memorial which we possess of Wren’s schoolboy days, is a dedication in Latin verse, addressed by him to his father in his thirteenth year, of an astronomical machine which he had invented, and which seems from his description to have been a sort of apparatus for representing the celestial motions, such as we now call an orrery. His genius is also stated to have displayed itself at this early age in other mechanical contrivances. [Illustration: _Engraved by W. Holl._ SIR CHRISTOPHER WREN. _From the original picture by Sir G. Kneller, in the possession of the Royal Society._ Under the Superintendance of the Society for the Diffusion of Useful Knowledge. _London. Published by Charles Knight, Pall Mall East._ ] In 1646 he was sent to Oxford, and entered as a gentleman commoner at Wadham College. Of his academical life we can say little more than that it confirmed the promise of his early proficiency. He was especially distinguished by his mathematical acquirements, and gained the notice and acquaintance of many of the most learned and influential persons belonging to the university. Several short treatises and mechanical inventions are assigned to this period of his life: but as these have long ceased to interest any but curious inquirers into the history of literature or science, we can only indicate their existence, and refer to other and more comprehensive works. In 1650 Wren graduated as Bachelor of Arts. He was elected Fellow of All Souls on the 2d of November, 1653, and took the degree of Master of Arts on the 12th of December in the same year. Of the subjects which engaged his active and versatile mind at this time, one of the chief was the science of Anatomy; and he is, on apparently good grounds, thought to have first suggested and tried the interesting experiment of injecting liquids of various kinds into the veins of living animals,—a process of surgery, which, applied to the transfusion of healthy blood into a morbid or deficient circulation, has been revived, not without some promise of important results, in our own day. Another subject which attracted much of his attention was the Barometer; but he has no claim whatever, either to the invention of that instrument, or to the detection of the great principle of physics, of which it is an exemplification. The notion which has been taken up of his right to supplant the illustrious Torricelli here, has arisen merely from mistaking the question with regard to the causes of the fluctuations in the height of the barometrical column, while the instrument continues in the same place, for the entirely different question as to the cause why the fluid