144 ROB 
from it to form a very favourable opinion of the writer, and 
to make a further trial of his proficiency. With this view 
the doctor sent him some problems, which Mr. Robins 
solved very much to his satisfaction, and with a degree of 
elegance which gave an advantageous idea of his taste as 
well as invention. The doctor now encouraged him to come 
to London, where he fully confirmed the good opinion which 
had been preconceived of his talents and knowledge. But 
though Mr. Robins already possessed 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 on the sublimer parts of the 
mathematics, before he undertook the task of instructing 
others. During this interval, besides improving himself in 
the modern languages, he carefully studied the writings of 
Apollonius, Archimedes, Fermat, Huygens, De Wit, Slu- 
sius, James Gregory, Barrow, Newton, Taylor, and Cotes. 
Of these authors he readily made himself master, without 
any assistance, as he convinced his friends by repeated 
proofs; and among others, by a demonstrat on of the last 
proposition of Newton’s Treatise on Quadratures, when he 
was only twenty years of age This performance was thought 
deserving of a place in the the “ Philosophical Transactions” 
for 1727; and towards the close of the same year he was ad¬ 
mitted a member of the Royal Society. In the course of 
the following year, he embraced an opportunity of offering 
to the public a specimen of his acquaintance with natural 
philosophy. The Royal Academy of Sciences at Paris, 
among their prize questions in 1724 and 1726, had asked 
for a demonstration of the laws of motion in bodies imping¬ 
ing on one another. On this occasion the celebrated John 
Bernouilli appeared in the list of candidates; and, as the 
judges did not decree the reward in his favour, he thought 
proper to appeal to the learned world, by publishing his 
demonstration, in the year 1727. In this piece he endeavour¬ 
ed, in opposition to Newton, to establish Leibnitz’s opinion 
of the force of bodies in motion, from the effects of their 
striking against elastic bodies; as Signor Poleni had before 
attempted to evince the same thing, from experiments of 
bodies falling on soft and yielding substances. The in¬ 
sufficiency of Poleni’s arguments had already been demon¬ 
strated in the “ Philosophical Transactions” for 1722, No. 
371.; and in “ The present State of the Republic of Let¬ 
ters," for May 1728, Mr. Robins published a confutation of 
Bernouilli’s performance, which was allowed to be unanswer¬ 
able. 
The employment which he professed to follow was that of 
a teacher of the mathematics only; yet he frequently assisted 
particular friends with advice and instructions on other sub¬ 
jects, as he was well qualified to do by the rich funds of 
knowledge with which his mind was stored. After some time, 
finding the confinement occasioned by his increasing engage¬ 
ments in the line of a teacher unsuitable to his disposition, 
which was naturally active, he gradually declined that em¬ 
ployment, and devoted his attention to other objects, which 
required more exercise. Among other things, he tried many 
laborious experiments in gunnery, from a belief that the 
resistance of the air had a much greater effect on swift pro¬ 
jectiles than was generally supposed. He also directed 
his studies to those mechanic arts which depend upon mathe¬ 
matical principles, in which he might have scope for the 
exercise of his invention ; such as the construction of mills, 
the building of bridges, draining of fens, rendering rivers 
navigable, and the making of harbours. The art of forti¬ 
fication, likewise, very much engaged his attention; in 
which he met with opportunities of perfecting himself, by 
an inspection of the principal strong places in Fjanders, 
during some journies which he made abroad with per¬ 
sons of distinction. Upon his return to England from one 
of these excursions, he found that the frequent subject of 
conversation in the learned world was a treatise by Dr. Berke¬ 
ley, published in 1734, under the title of “The Analyst;” 
in which the author examined into the grounds of the doc¬ 
trine of fluxions, and endeavoured to explode that method. 
This treatise Mr. Robins was advised, to refute, by giving a 
I N S. 
full and distinct account of Newton’s doctrine, in such a 
manner as to obviate all the objections advanced by' Dr. 
Berkeley, without naming them. Accordingly, in 1735, he 
published “A Discourse concerning the Nature and Cer¬ 
tainty of Sir Isaac Newton’s Method of Fluxions, and of 
prime and ultimate Ratios," which is a very perspicuous, 
neat, and elegant performance. There were, however, some 
persons, even among those wjio had written against “ The 
Analyst,” who excepted against Robins’s manner of defend¬ 
ing Newton’s doctrine; on which account he wrote two or 
three additional pieces in vindication of his discourse, and 
to shew, that the view of the doctrines of fluxions, and of 
prime and ultimate ratios contained in it, is agreeable to the 
meaning of their great inventor. In 1738, he also defended 
Newton against an objection contained in a note at the end 
of Baxter’s “ Matho, sive Cosmotheoria puerilis;” and in 
the following year, he published “ Remarks on Euler’s Trea¬ 
tise of Motion, Dr. Smith’s System of Optics, and Dr, 
Jurin’s Discourse of distinct and indistinct Vision.” 
But Mr. Robins’s performances were not confined to ma¬ 
thematical and pilosophical subjects. In 1739 he published, 
without his name, three pamphlets on political affairs; the 
first entitled, “ Observations on the present Convention with 
Spain;” the second, “A Narrative of what had passed in 
the Common-hall of the Citizens of London, assembled for 
the Election of a Lord-Mayor;” and the third, “An Address 
to the Electors and other free Subjects of Great Britain, occa¬ 
sioned by the late Succession ; in which is contained a par¬ 
ticular Account of all our Negociations with Spain, and 
their Treatment of us for above ten Years past.” The first 
and last of these pieces, which were ably written, and on the 
popular side of the question, were for some time reputed to 
be the productions of Mr. Pulteney, who was now at the 
head of the opposition to Sir Robert Walpole. So high did 
they raise Mr. Robins in Ihe estimation of the patriots, that 
when a committee of the House of Commons was appointed 
to examine into the conduct of that minister, he had the 
honour of being chosen their secretary. After this com¬ 
mittee had presented two reports of their proceedings, the 
compromise which took place between the contending parties 
put a stop to their further progress. In 1742, our author 
published a small treatise, entitled, “New Principles of Gun¬ 
nery ;” containing the result of many experiments, by which 
he discovered the force of gunpowder, and the difference in 
the resisting power of the air to swift and slow motions. 
Hence it plainly appeared, that the opposition of that me¬ 
dium to bullets and shells, discharged from cannon and mor¬ 
tars, far exceeded what was generally imagined; and that 
the track which their motion described, differed from that 
of a parabolic line to a degree undiscovered by any who 
had written expressly on the subject from the time of the 
celebrated Galileo. Prefixed to this treatise is a full and 
learned account of the progress which modern fortification 
had made from its first rise, and of what had already been 
performed in the theory of gunnery. It appears that this, 
publication was undertaken by Mr. Robins, in consequence 
of his having been disappointed of a situation in the Royal 
Military Academy at Woolwich, for which he was a candi¬ 
date. On the new modelling of that academy in 1741, our 
author and Mr. Muller were competitors for the place of 
Professor of Fortification and Gunnery. The latter gentleman 
held at that time some post in the Tower of London, under 
the Board of Ordnance; and so great was his interest with 
that board, that, notwithstanding the great knowledge and 
abilities of our author, the election was carried in favour of 
Mr. Muller. Upon this Mr. Robins, indignant at the prefer¬ 
ence which they had given his rival, determined to shew 
them and the world, by printing this treatise, his superior 
qualifications for that appointment Some time after the 
publication of this work, a paper having been admitted into 
the “Philosophical Transactions,” containing experiments 
intended to invalidate some of our author’s opinions, he 
though t proper, in an account which he gave of his book 
in the same Transactions, to take some notice of those expe¬ 
riments. In consequence of this, several of his dissertations 
