What seems to fix the start of Wren’s studies with Scarborough as roughly contemporary with his Panorganum letter is the fact that the boy in 1647 was engaged in translating into Latin, at Sir Charles’ request, Oughtred’s Clavis Mathematicæ. In the same year he had a patent granted him for a diplographic instrument for writing with two pens. Christopher describes his invention at length. An instrument of the kind must have then seemed very important, because Sir William Petty patented a similar contrivance in the same year. About three years later someone stole Wren’s invention. He was exceedingly annoyed, and wrote a letter in which he refers to the fact that Oliver Cromwell’s attention had been directed to it. Without claiming anything great for the invention itself, he wanted to clear himself from the aspersion of having annexed somebody else’s device. In later years there were to be many examples of people picking up an idea of Wren’s, developing it to their own great credit, and failing to acknowledge the man without whose idea they never would have started on their enterprise.
Whenever it was that Wren began working under Sir Charles Scarborough, it was not until his fifteenth year that he informed his father that he was acting as a demonstrating assistant to the physician who lectured on anatomy at Surgeons’ Hall. The story of his activities is set out in a dignified Latin letter, which refers not only to the Scarborough activities, but to Wren’s invention of a weather-clock, of an instrument to write with in the dark, and of a treatise on spherical trigonometry. Very impressive also is a long metrical Latin essay on the Reformation of the Zodiac, which runs to nearly fifteen quarto pages, in an appendix to Elmes’ Life. He was sixteen when he wrote (again in Latin) to Mr. Oughtred, whose important essay on geometry he had translated into Latin. We may agree with Elmes that “these juvenile essays prove the fecundity, the ripeness, and the highly cultivated state of his mind, his zeal, and his ardent enthusiasm in the pursuit of knowledge and literary honours.”
But the weather-clock was destined to develop from the stage of a “juvenile essay.” When he wrote to his father in 1647 that he was enjoying Scarborough’s society, he added that he had imparted to him “one of these inventions of mine, a weather-clock—namely, with revolving cylinder, by means of which a record can be kept through the night.”
Of this Scarborough thought well enough to ask the lad to have one constructed in brass at his expense. I find in Birch’s History of the Royal Society, vol. i., under date December 9, 1663: “Dr. Wren’s description of his weather-clock consisting of two wings that may be added to a pendulum clock was read.” The engraving published by Birch shows a far simpler arrangement than that of the drawing among the heirloom MSS. The printed Parentalia gives a description of a device more complicated than Birch’s description of Wren’s communication of 1663, and refers to a circular thermometer designed to correct the error caused by the weight of liquid. This does not appear in the drawing; the thermometer is of the ordinary air type. The printed Parentalia refers to Robert Hooke’s improvements on Wren’s design, but they only partly appear in the drawing, which would seem to show an intermediate development between Wren’s original device and Hooke’s latest achievements.
The thing itself is of no importance now, but is worth remembering, as showing not only the early blossoming of Wren’s scientific achievement, but also his patience and persistence in developing an idea over a period of years.
All this was a good prelude to his life at Oxford, which began when he was young to be an undergraduate, by our standards, but older than we have been led to believe.
CHAPTER II
OXFORD CAREER AND EARLY INVENTIONS
The question as to when Wren started his University career presents considerable difficulties, but it is worth exploring, because his youth at Oxford had an enduring effect on the development of the man.
Parentalia is explicit: “In the year 1646 and Fourteenth of his Age, Mr. Wren was admitted a Gentleman-Commoner at Wadham College ... where he soon attracted the Friendship and esteem of the two most celebrated Virtuosi and Mathematicians of their Time, Dr. John Wilkins, Warden of Wadham, and Dr. Seth Ward....” This date is confirmed by the Lansdowne Chronology MS., prepared by Wren’s son, and initialed by Sir Christopher himself two years before his death. The MS. states:
“1646. Admissus in Collegio de Wodham.”