princely benefactor nor Gregory, whom he had appointed a referee, lived to see the work completed. Gregory had, in 1702, dedicated his _Book on the Elements of Astronomy_, to the prince, drawing a comparison while he did it between Prince George of Denmark, the patron of science, and that King of Denmark who had so wisely given to the great Danish astronomer, Tycho Brahe, the wonderful observatory of Uraniborg—the city of the heavens. The Preface of this book begins quaintly with a delicious run of mixed metaphors—‘My Design in publishing this Book, was, that the Celestial Physicks, which the most sagacious Kepler had got the scent of, but the Prince of Geometers, Sir Isaac Newton, brought to such a pitch as surprises all the World, might by my Care and Pains in illustrating them, become easier to such as are desirous of being acquainted with Philosophy and Astronomy.’ In this book there is a most curious mixture of history, imagination, ideas of Newton’s, which the philosopher had communicated to him, and observations. It was of course, as was usual at that time, written in Latin, but Edmund Stone translated it into English in 1726, and this was the book which Samuel Johnson read with so much acceptance in some of his dull days in the Island of Coll. Gregory imagined the stars as they would appear to the inhabitants of the satellites of Jupiter and Saturn, and gave to his book that inexpressible charm of individuality, so often present in the Gregories’ writings, which makes them draw portraits of themselves as they write their books. In this treatise he elucidated the principles of astronomy with all the wonderful improvements made in his day, and Newton himself considered it a masterly explanation in defence of his philosophy. Every now and then Gregory would go to spend some weeks with his friend at Cambridge. On one of these visits it was that Sir Isaac had occasion to express his views upon the superstitions of the day. He passed a house opposite St John’s College, which was supposed to be haunted, and round the doors was collected a crowd not only of undergraduates but of Fellows, and some of them Fellows of Trinity. Noticing that some of the rabble were carrying arms, his anger burst out. ‘Oh, ye fools,’ he said, ‘will ye never have any wit? Know ye not that all such things are mere cheats and impostures? Fie! fie! Go home, for shame.’ When Gregory arrived at Cambridge he was always full of messages for Sir Isaac, and when he left, equally so with messages from him. In this way he saw a good deal of all the important mathematicians and astronomers then living in Great Britain, and very likely it added to his already considerable reputation. In 1705 he was elected an Honorary Fellow of the Royal College of Physicians of Edinburgh, and on the 4th of October he took his seat at the Board. This was no doubt an honour obtained for him by his friend Pitcairne, who was then examiner, but Gregory could not spend much time away from England.