(Benjamin), a most ingenious English mathematician, born at Bath in 1707. His parents were Quakers and of low condition, consequently neither able nor willing to have him much instructed in human learning. Nevertheless his own propensity to science procured him a recommendation to Dr Pemberton at London; by whose assistance, while he attained the sublimer parts of mathematical knowledge, he commenced teacher of the mathematics. But the business of teaching, which required confinement, not suiting his active disposition, he gradually declined it, and engaged in business that required more exercise. Hence he tried many laborious experiments in gunnery, from the persuasion that the respiration of the air has a much greater influence on swift projectiles than is generally imagined. Hence also he was led to consider the mechanic arts that depend on mathematical principles; as the construction of mills, the building of bridges, the draining of fens, the rendering of rivers navigable, and the making of harbours. Among other arts, fortification much engaged his attention; and he met with opportunities of perfecting himself by viewing the principal strong places of Flanders, in some tours he made abroad with persons of distinction.

Upon his return from one of these excursions, he found the learned amused with Dr Berkley's work, intitled The Analyst, in which an attempt was made to explode the method of fluxions. Mr Robins was therefore advised to clear up this affair by giving a distinct account of Sir Isaac Newton's doctrines, in such a manner as to obviate all the objections that had been made without naming them. Accordingly he published, in 1735, A Discourse concerning the Nature and Certainty of Sir Isaac Newton's Method of Fluxions; and some exceptions being made to his manner of defending Sir Isaac Newton, he afterwards wrote two or three additional discourses. In 1738 he defended the same great philosopher against an objection contained in a note at the end of a Latin piece, called Mathe, seu Cosmographia paucitatis; and the following year printed Remarks on M. Euler's Treatise of Motion, on Dr Smith's system of Optics, and on Dr Jurin's Discourse of distinct and indistinct Vision. annexed to Dr Smith's work. In the mean while Mr Robins did not solely confine himself to mathematical subjects; for in 1739 he published three pamphlets on political affairs, without his name; when two of them, relating to the convention and negotiations with Spain, were so universally esteemed, as to occasion his being employed in a very honourable post; for on a committee being appointed to examine into the past conduct of Sir Robert Walpole, he was chosen their secretary.

In 1742, Mr Robins published a small treatise, intitled New Principles of Gunnery, containing the result of many experiments; when a Discourse being published in the Philosophical Transactions, in order to invalidate some of his opinions, he thought proper, in an account he gave of his book in the same Transactions, to take notice of those experiments; in consequence of which several of his Dissertations on the Resistance of the Air were read, and the experiments exhibited before the Royal Society, for which he was presented by that honourable body with a gold medal.

In 1748 appeared lord Anson's Voyage round the World, which, though Mr Walter's name is in the title, was in reality written by Mr Robins. Mr Walter, chaplain on board the Centurion, had indeed brought it down to his departure from Macao for England, when he proposed to print the work by subscription. It was however thought proper that an able judge should review and correct it, and Mr Robins was appointed; when, upon examination, it was resolved that the whole should be written by Mr Robins, and that what Mr Walter had done should only serve as materials. Hence the introduction entire, and many dissertations in the body of the work, were composed by him, without receiving the least assistance from Mr Walter's manuscript, which chiefly related to the wind and the weather, the currents, courses, bearings, distances, the qualities of the ground on which they anchored, and such particulars as generally fill up a sailor's account. No production of this kind ever met with a more favourable reception; four large impressions were sold within a twelvemonth; and it has been translated into most of the languages of Europe. The fifth edition printed at London in 1749, was revised and corrected by Mr Robins himself.

Having thus rendered himself famous for his ability in writing, he was desired to compose an apology for the unfortunate affair at Preston-Pans in Scotland, which was prefixed as a preface to The Report of the Proceedings of the Board of general Officers, on their examination into the conduct of Lieu. Gen. Sir John Cope; and this preface was esteemed a master-piece in its kind. He afterwards, through the interest of lord Anson, contributed to the improvements made in the royal observatory at Greenwich. Having thus established his reputation, he was offered the choice of two considerable employments; either to go to Paris as one of the commissaries for adjusting the limits of Acadia, or to be engineer general to the East India company. He chose the latter, and arrived in the East Indies in 1750; but the climate not agreeing with his constitution, he died there the year following.