ROBINS (Benjamin)

, an English mathematician and philosopher of great genius and eminence, was born at Bath in Somersetshire, 1707. His parents were of low condition, and Quakers; and consequently neither able from their circumstances, nor willing from their religious profession, to have him much instructed in that kind of learning which they are taught to despise as human. Nevertheless, he made an early and surprising progress in various branches of science and literature, particularly in the mathematics; and his friends being desirous that he might continue his pursuits, and that his merit might not be buried in obscurity, wished that he could be properly recommended | to teach that science in London. Accordingly, a specimen of his abilities in this way was sent up thither, and shewn to Dr. Pemberton, the author of the “View of Sir Isaac Newton's Philosophy;” who, thence conceiving a good opinion of the writer, for a farther trial of his skill sent him some problems, which Robins resolved very much to his satisfaction. He then came to London, where he confirmed the opinion which had been preconceived of his abilities and knowledge.

But though Robins was possessed of much more skill than is usually required in a common teacher; yet being very young, it was thought proper that he should employ some time in perusing the best writers upon the sublimer parts of the mathematics, before he should undertake publicly the instruction of others. In this interval, besides improving himself in the modern languages, he had opportunities of reading in particular the works of Archimedes, Apollonius, Fermat, Huygens, De Witt, Slusius, Gregory, Barrow, Newton, Taylor, and Cotes. These authors he readily understood without any assistance, of which he gave frequent proofs to his friends: one was, a demonstration of the last proposition of Newton's treatise on Quadratures, which was thought not undeserving a place in the Philosophical Transactions for 1727.

Not long after, an opportunity offered him of exhibiting to the public a specimen also of his knowledge in Natural Philosophy. The Royal Academy of Sciences at Paris had proposed, among their prize questions in 1724 and 1726, to demonstrate the laws of motion in bodies impinging on one another. John Bernoulli here condescended to be a candidate; and as his dissertation lost the reward, he appealed to the learned world by printing it in 1727. In this piece he endeavoured to establish Leibnitz's opinion of the force of bodies in motion from the effects of their striking against springy materials; as Poleni had before attempted to evince the same thing from experiments of bodies falling on soft and yielding substances. But as the insufficiency of Poleni's arguments had been demonstrated in the Philosophical Transactions, for 1722; so Robins published in the Present State of the Republic of Letters, for May 1728, a Coufutation of Bernoulli's performance, which was allowed to be unanswerable.

Robins now began to take scholars; and about this time he quitted the garb and profession of a Quaker; for, having neither enthusiasm nor superstition in his nature, as became a mathematician, he soon shook off the prejudices of such early habits. But though he professed to teach the mathematics only, he would frequently assist particular friends in other matters; for he was a man of universal knowledge: and the confinement of this way of life not suiting his disposition, which was active, he gradually declined it, and went into other courses, that required more exercise. Hence he tried many laborious experiments in gunnery; believing that the resistance of the air had a much greater effect on swist projectiles, than was generally supposed. And hence he was led to consider those mechanic arts that depend upon mathematical principles, in which he might employ his invention: as, the constructing of mills, the building of bridges, draining of fens, ren- dering of rivers navigable, and making of harbours. Among other arts of this kind, fortification very much engaged his attention; in which he met with opportunities of perfecting himself, by a view of the principal strong places of Flanders, in some journeys he made abroad with persons of distinction.

On his return home from one of these excursions, he found the learned here amused with Dr. Berkeley's treatise, printed in 1734, entitled, “The Analyst;” in which an examination was made into the grounds of the doctrine of Fluxions, and occasion thence taken to explode that method. Robins was therefore advised to clear up this affair, by giving a full and distinct account of Newton's doctrines, in such a manner, as to obviate all the objections, without naming them, which had been advanced by Berkeley; and accordingly he published, in 1735, A Discourse concerning the Nature and Certainty of Sir Isaac Newton's Method of Fluxions, and of Prime and Ultimate Ratios. This is a very clear, neat, and elegant performance: and yet some persons, even among those who had written against The Analyst, taking exception at Robins's manner of defending Newton's doctrine, he afterwards wrote two or three additional discourses.

In 1738, he defended Newton against an objection, contained in a note at the end of a Latin piece, called “Matho, five Cosmotheoria puerilis,” written by Baxter, author of the “Inquiry into the Nature of the Human Soul:” and the year after he printed Remarks on Euler's Treatise of Motion, on Smith's System of Optics, and on Jurin's Discourse of Distinct and Indistinct Vision, annexed to Dr. Smith's work.

In the mean time Robins's performances were not confined to mathematical subjects: for, in 1739, there came out three pamphlets upon political affairs, which did him great honour. The first was entitled, Observations on the present Convention with Spain: the second, A Narrative of what passed in the Common Hall of the Citizens of London, assembled for the Election of a Lord Mayor: the third, An Address to the Electors and other free Subjects of Great Britain, occasioned by the late Succession; in which is contained a Particular Account of all our Negociations with Spain, and their Treatment of us for above ten years past. These were all published without our author's name; and the first and last were so universally esteemed, that they were generally reputed to have been the production of the great man himself, who was at the head of the opposition to Sir Robert Walpole. They proved of such consequence to Mr. Robins, as to occasion his being employed in-a very honourable post; for, the patriots at length gaining ground against Sir Robert, and a committee of the House of Commons being appointed to examine into his past conduct, Robins was chosen their secretary. But after the committee had presented two reports of their proceedings, a sudden stop was put to their farther progress, by a compromise between the contending parties.

In 1742, being again at leisure, he published a small treatise, entitled, New Principles of Gunnery; containing the result of many experiments he had made, by which are discovered the force of gunpowder, and the difference in the resisting power of the air to swist and | slow motions. To this treatise was prefixed a full and learned account of the progress which modern fortification had made from its first rise; as also of the invention of gunpowder, and of what had already been performed in the theory of gunnery. It seems that the occasion of this publication, was the disappointment of a situation at the Royal Military Academy at Woolwich. On the new modelling and establishing of that Academy, in 1741, our author and the late Mr. Muller were competitors for the place of professor of fortification and gunnery. Mr. Muller held then some post in the Tower of London, under the Board of Ordnance, so that, notwithstanding the great knowledge and abilities of our author, the interest which Mr. Muller had with the Board of Ordnance carried the election in his favour. Upon this disappointment Mr. Robins, indignant at the affront, determined to shew them, and the world, by his military publications, what sort of a man he was that they had rejected.

Upon a discourse containing certain experiments being published in the Philosophical Transactions, with a view to invalidate some of Robins's opinions, he thought proper, in an account he gave of his book in the same Transactions, to take notice of those experiments: and in consequence of this, several dissertations of his on the resistance of the air were read, and the experiments exhibited before the Royal Society, in 1746 and 1747; for which he was presented with the annual gold medal by that Society.

In 1748 came out Anson's Voyage round the World; which, though it bears Walter's name in the title-page, was in reality written by Robins. Of this voyage the public had for some time been in expectation of seeing an account, composed under that commander's own inspection: for which purpose the reverend Richard Walter was employed, as having been chaplain on board the Centurion the greatest part of the expedition. Walter had accordingly almost finished his task, having brought it down to his own departure from Macao for England; when he proposed to print his work by subscription. It was thought proper however that an able judge should first review and correct it, and Robins was appointed; when, upon examination, it was resolved, that the whole should be written entirely by Robins, and that what Walter had done, being mostly taken verbatim from the journals, should serve as materials only. Hence it was that the whole of the introduction, and many dissertations in the body of the work, were composed by Robins, without receiving the least hint from Walter's manuscript; and what he had transcribed from it regarded chiefly the wind and weather, the currents, courses, bearings, distances, offings, soundings, moorings, the qualities of the ground they anchored on, and such particulars as usually fill up a seaman's account. No production of this kind ever met with a more favourable reception, four large impressions having been sold off within a year: it was also translated into most of the European languages; and it still supports its reputation, having been repeatedly reprinted in various sizes. The fifth edition at London in 1749 was revised and corrected by Robins himself; and the 9th edition was printed there in 1761.

Thus becoming famous for his elegant talents in writing, he was requested to compose an apology for the unfortunate affair at Prestonpans in Scotland. This was added as a preface to the Report of the Proceedings and Opinion of the Board of General Officers on their Examination into the Conduct of Lieutenant General Sir John Cope, &c, printed at London in 1749; and this preface was esteemed a master-piece in its kind.

Robins had afterwards, by the favour of lord Anson, opportunities of making farther experiments in Gunnery; which have been published since his death, in the edition of his works by his friend Dr. Wilson. He also not a little contributed to the improvements made in the Royal Observatory at Greenwich, by procuring for it, through the interest of the same noble person, a second mural quadrant, and other instruments; by which it became perhaps the completest of any observatory in the world.

His reputation being now arrived at its full height, he was offered the choice of two very considerable employments. The first was to go to Paris, as one of the commissaries for adjusting the limits in Acadia; the other, to be engineer general to the East India Company, whose forts, being in a most ruinous condition, wanted an able person to put them into a proper state of defence. He accepted the latter, as it was suitable to his genius, and as the Company's terms were both advantageous and honourable. He designed, if he had remained in England, to have written a second part of the Voyage round the World; as appears by a letter from lord Anson to him, dated Bath, Oct. 22, 1749, as follows.

“Dear Sir, when I last saw you in town, I forgot to ask you, whether you intended to publish the second volume of my Voyage before you leave us; which I confess I am very sorry for. If you should have laid aside all thoughts of favouring the world with more of your works, it will be much disappointed, and no one in it more than your very obliged humble servant, “Anson.”

Robins was also preparing an enlarged edition of his New Principles of Gunnery: but, having provided himself with a complete set of astronomical and other instruments, for making observations and experiments in the Indies, he departed hence at Christmas in 1749; and after a voyage, in which the ship was near being cast away, he arrived at India in July following. There he immediately set about his proper business with the greatest diligence, and formed complete plans for Fort St. David and Madras: but he did not live to put them into execution. For the great difference of the climate from that of England being beyond his constitution to support, he was attacked by a sever in September the same year; and though he recovered out of this, yet about eight months after he sell into a langnishing condition, in which he continued till his death, which happened the 29th of July 1751, at only 44 years of age.

By his last will, Mr. Robins lest the publishing of his Mathematical Works to his honoured and intimate friend Martin Folkes, Esq. president of the Royal Society, and to Dr. James Wilson; but the former of these | gentlemen being incapacitated by a paralytic disorder, for some time before his death, they were afterwards published by the latter, in 2 volumes 8vo, 1761. To this collection, which contains his mathematical and philosophical pieces only, Dr. Wilson has presixed an account of Mr. Robins, from which this memoir is chiefly extracted. He added also a large appendix at the end of the second volume, containing a great many curious and critical matters in various interesting parts of the mathematics. As to Mr. Robins's own papers in these two volumes, they are as follow: viz, in vol. I,

1. New Principles of Gunnery. First printed in 1742.

2. An Account of that book. Read before the Royal Society, April the 14th and 21st 1743.

3. Of the Resistance of the Air. Read the 12th of June 1746.

4. Of the Resistance of the Air; together with the Method of computing the Motions of Bodies projected in that Medium. Read June 19, 1746.

5. Account of Experiments relating to the Resistance of the Air. Read the 4th of June 1747.

6. Of the Force of Gunpowder, with the Computation of the Velocities thereby communicated to military projectiles. Read the 25th of June 1747.

7. A Comparison of the Experimental Ranges of Cannon and Mortars, with the Theory contained in the preceding papers. Read the 27th of June 1751.

8. Practical Maxims relating to the Effects and Management of Artillery, and the Flight of Shells and Shot.

9. A Proposal for increasing the Strength of the British Navy. Read the 2d of April 1747.

10. A Letter to Martin Folkes, Esq. President of the Royal Society. Read the 7th of January 1748.

11. A Letter to Lord Anson. Read the 26th of October 1749.

12. On Pointing, or Directing of Cannon to strike distant objects.

13. Observations on the Height to which Rockets ascend. Read the 4th of May 1749.

14. An Account of some Experiments on Rockets, by Mr. Ellicott.

15. Of the Nature and Advantage of Rifled Barrel Pieces, by Mr. Robins. Read the 2d of July 1747.

In volume II are,

16. A Discourse concerning the Nature and Certa nty of Sir Isaac Newton's Methods of Fluxions, and of Prime and Ultimate Ratios.

17. An Account of the preceding Discourse.

18. A Review of some of the principal Objections, that have been made to the Doctrine of Fluxions and Ultimate Proportions, with some Remarks on the different Methods, that have been taken to obviate them.

19. A Dissertation shewing, that the Account of the Doctrines of Fluxions and of Prime and Ultimate Ratios, delivered in Mr. Robins's Discourse, is agreeable to the real Meaning of their great Inventor.

20. A Demonstration of the Eleventh Proposition of Sir Isaac Newton's Treatise of Quadratures.

21. Remarks on Bernoulli's Discourse upon the Laws of the Communication of Motion.

22. An Examination of a Note concerning the Sun's Parallax, published at the end of Baxter's Matho.

23. Remarks on Euler's Treatise of Motion; Dr. Smith's System of Optics; and Dr. Jurin's Essay on Distinct and Indistinct Vision.

24. Appendix by the Publisher.

It is but justice to say, that Mr. Robins was one of the most accurate and elegant mathematical writers that our language can boast of; and that he made more real improvements in Artillery, the flight and the resistance of projectiles, than all the preceding writers on that subject. His New Principles of Gunnery were translated into several other languages, and commented upon by several eminent writers. The celebrated Euler translated the work into the German language, accompanied with a large and critical commentary; and this work of Euler's was again translated into English in 1714, by Mr. Hugh Brown, with Notes, in one volume 4to.