It was chiefly owing to the celebrated Halley, that Dr. Simson so early directed his efforts to the restoration of the ancient geometers. He had recommended this to him, as the most certain way for him, at that time very young, both to acquire reputation, and to improve his own know. ledge and taste, and he presented him with a copy of Pappus's Mathematical Collections, enriched with his own notes. Hence he undertook the restoration of Euclid's porisms, a work of such difficul ty, that his biographer says nothing but success could justify in so young an adventurer. From this he proceeded to other works of importance, which he ex ecuted with so much skill, as to obtain the reputation of being one of the most elegant geometers of the age. His edi tion of Euclid's " Elements" has long been reckoned the very best that exists. Another work, on which Dr. Simson be stowed much labour, was the " Sectio de terminata," which was published after his death, by the late Earl Stanhope, with the great work, " The Porisms of Euclid." This nobleman had kept up a correspon dence with Dr. Simson till his death, in 1768, when he engaged Mr. Clow, to whose care the Doctor had left his pa pers, to make It selection of such as would serve to support and increase his reputation, as the restorer of ancient ge. ometry. This selection 'Lord Stanhope printed at his own expense.
" The life of a literary man rarely teems with anecdote ; and a mathematician, de voted to his studies, is perhaps more ab stracted than any other person from the ordinary occurrences of life, and even the ordinary topics of conversation. Dr. Sim son was of this class ; and having never married, lived entirely a college life. Having no occasion for the commodious house to which his place in the university entitled him, he contented himself with chambers, good indeed, and spacious enough for his sober accommodation, and for receiving his choice collection of ma thematical writers, but without any de coration or commodious furniture. His official servant sufficed for valet, footman, and chambermaid. As this retirement was entirely devoted to study, he enter tained no company in his chambers, but in a neighbouring house, where his apart ment was sacred to him and his guests.
Having in early life devoted himself to the restoration of the works of the ancient geometers, he studied them with unre mitting attention ; and retiring from the promiscuous intercourse of the world, he contented himself with a small society of intimate friends, with whom he could lay aside every restraint of ceremony or re serve, and indulge in all the innocent fri volities of life. Every Friday evening was spent in a party at whist, in which he excelled, and took delight in instructing others, till increasing years made him less patient with the dulness of a scholar. The card-party was followed by an hour or two dedicated solely to playful con versation. In like manner, every Satur day he had a less select party to dinner at a house about a mile from town. The Doctor's long life gave him occasion to see the dramatis persona of this little theatre several times completely changed, while he continued to give it a personal identity; so that, without any design or wish of his own, it became, as it were, his own house and his own family, and went by his name. Dr. Simson was of an advantageous stature, with a tine counte nance; and even in his old age had a graceful carriage and manner, and al ways, except when in mourning, dressed in white cloth. lie was of a cheerful disposition ; and though he did not make the first advances to acquaintance, had the most affable manner, and strangers were at perfect case in his company. He enjoyed a long course of uninterrupted health, but towards the close of life suf fered from an acute disease, and was ob liged to employ an assistant in his profes sional labours for a few years preceding his death, which happened in 1768, at the age of eighty-one. lie left to the univer sity his valuable library, which is now ar ranged apart from the rest of the books, and the public use of it is limited by par ticular rules. It is considered as the most choice collection of mathematical books and manuscripts in the kingdom, and ma ny of them are rendered doubly valuable by Dr. Simson's notes." For a more particular account of the life and writings of this great man, the reader is referred to the article in the Encyclopedia Britan nica, vol. xvii.