BARRO , ISAAC, an eminent theologian and a profound mathematician, was born in London, tober 1630. His father, Thomas Barrow, merchant, was brother of the bishop of St Asaph, and nearly related to several other distinguished men. He re ' ceived the earliest part of his education at the Char ter-house, where he was remarkable only for inatten tion, slovenliness, and a most quarrelsome disposition. His father, who had destined him for a learned pro. fession, was so discouraged by these untoward ap pearances, that he often wished, if Providence were ever to deprive him of any of his children, that it might be Isaac, from whom lie promised himself no comfort. But having afterwards sent him to a school at Felsted in Essex, he soon perceived the dawn of his future excellence. At the age of fifteen, he was placed at Trinity College; Cambridge, where he was supported chiefly by the liberality of the learned Dr Hammond. His father's circumstances had been greatly reduced by his attachment to the cause of the unfortunate Charles I. ; and young Barrow, who had imbibed the same loyal partialities, could not be prevailed upon, by any temptation of interest, to de clare his adherence to the republican party. Yet, by his diligence, prudence, and candour, by the man liness of his principles, and the purity of his morals, he recommended himself to the esteem of the heads of the university, though little favour could then be expected by any who refused to subscribe the covenant. During his residence at the university, he applied with great eagerness to every branch of useful learn ing; but his chief attention was paid to the writings of Bacon, Galileo, Descartes, and the other refor mers of philosophy. In 1,649, notwithstanding the odium to which his loyalty exposed him, his indis putable merit obtained him a fellowship ; and for some time after his election, being convinced that a man of his principles could have no opportunity of being useful in the church, he resolved to make phy sic his profession. For a few years, therefore, he applied to the study of anatomy, chemistry, and the other branches of a medical education ; but after far ther deliberation, he returned to the study of divinity, from which he conceived he could not withdraw, without violating the oath he bad taken at his ad mission to a fellowship.
It is affirmed, that he was led to the study of ma. thematics by reading Scaliger on Eusebius. Per ceiving that chronology is founded on the basis of astronomy, , he began to read some works on this science ; and foreseeing that his labour would be 'fruitless, unless he previously gained an acquaintance with the principles of geometry, he determined to make himself master of the writings of the ancient mathematicians. Not satisfied with improving his own mind by these exercises, to which he bent his attention with almost unprecedented perseverance, lie prepared and published more correct editions of the works of Euclid, Archimedes, and Apollonius, than had hitherto been presented to the world. This, however, is not the whole extent of his merit. Though not of a genius so inventive as Newton, he made a near approach to some of that wonderful man's discoveries, and contributed in a very remark able degree to enlarge the field of mathematical learn ing.
Barrow was recommended by Dr Duport, on his resignation of the Greek professorship, as the fittest person to succeed him ; but, though his qualifica tions were universally acknowledged, his alleged ten dency to Arminianism obstructed his advancement on ' this occasion. In 1651., he travelled into France, and had the happiness of administering to the wants of his father, whom he found at Paris, in the retinue of the English court. From France he proceeded to Italy' and resided for some time at Florence, where he' perused many books and medals in the grand duke's library. He was deterred by the plagde from visiting. Rome, and, in the end of the year 1657, lie sailed for Smyrna. During the voyage, he had an opportunity of signalizing his courage in a fierce and obstinate engagement with a pirate. He remained in Turkey more than a year, and at Constantinople he employed himself in reading the works of Chry sostom, formerly bishop of that see, and in studying the institutions and manners of the people. He re turned home by the way of Venice, Germany, and Holland, and, soon after his arrival in England, lie was ordained by Bishop Brownrigg.