ON Dec. 29 occurs the bicentenary of the death of Brook Taylor, who in his day was considered the most notable British mathematician after Newton, and who counted among his contemporaries Halley, Cotes, Saunderson, Colson and Maclaurin. Born on Aug. 18, 1685, at Edmonton, Middlesex, Taylor entered St. John's College, Cambridge, and in 1701, while there, began a correspondence with Keill of Oxford. He was elected a fellow of the Royal Society in 1712 and from that time onwards he contributed papers to the Philosophical Transactions, discussing the motion of projectiles, the centre of oscillation, and the forms taken by liquids when raised by capillarity. In 1715 he published his important work “Methodus Incremen-torum Directa et Inversa”, the first treatise dealing with the calculus of finite differences. It contained the famous ‘Taylor's theorem’, the importance of which was, however, not fully realised until pointed out by Lagrange. Taylor also published, in 1715 and 1719 respectively, two works on linear perspective which contained the earliest general enunciation of the principle of vanishing points. In 1714, he became one of the secretaries of the Royal Society, but resigned this post in 1718 and soon afterwards abandoned the study of mathematics. He long suffered from consumption, and he died at Somerset House on Dec. 29, 1731, at the age of forty-six years, two years after succeeding to his father's estate in Kent. He was twice married, his second wife dying in 1730, leaving him a daughter who married Sir William Young. Taylor was buried in the churchyard of St. Anne's, Soho.