ROBINS, 
.don, 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 em- 
ploy some time in perusing the best writers, 
upon the sublimer parts of the mathema- 
tics, before he should undertake publicly 
the instruction of others. In this interval, 
besides imirroving 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 un- 
derstood 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 Philos. Tran^. for 
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 an- 
other. John Bernoulli here condescended 
to be a canditate; 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 ma- 
terials ; as Poleni had before attempted to 
evince the same thing from experiments of 
bodies falling on soft and yielding sub- 
stances. But as the insufficiency of Po- 
leni’s arguments had been demonstrated in 
the Philos. Trans, for 1722 ; so Robins pub- 
lished in the “ Present State of the Republic 
of Letters,” for May 1728, a Confutation of 
Bernoulli’s performance, which was allowed 
to be unanswerable. 
Robins now began to take scholars. 
About this time he quitted the dress and 
profession of a qnaker; and, probably, 
without reflecting very much upon the 
subject of religion, he soon shook off 
tlie prejudices of his early habits. But 
though he professed to teach the mathema- 
tics only, he would frequently assist parti- 
cular 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 gra- 
dually 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 swift 
projectiles, than was generally supposed. 
And hence he was led to consider those 
mechanic arts that depend upon mathema- 
tical principles, in whicli he might employ 
his invention ; as the constructing of mills, 
the building of bridges, draining of fens, 
rendering of rivers navigable, and making 
of harbours. Among other arts of this 
kind, fortification very much engaged his 
attention ; in which he met with opportu- 
nities of perfecting himself, by a view of 
the principal strong places of Flanders, in 
some journies he made abroad with persons 
of distinction. 
On his return home from one of these ex- 
cursions, he found the learned here amused 
with Dr. Berkeley’s treatise, printed in 
1734, entitled “The Analyst,”.* in which aii 
examination was made into the grounds of 
the Doctrine of Fluxions, and occasion 
thence taken to explode that method, Ro- 
bins was, therefore, advised to clear up this 
aftair, by giving a full and distinct account 
of Newton’s doctrines, in such a manner as 
to obviate all the objections, without nam- 
ing them which had been advanced by 
Berkeley, and accordingly he publishfed, in 
1735, a Discourse concerning the Nature 
and Certainty of Sir Isaac N e wton’s Method 
of Fluxions, and of Prime and Ultimate 
Ratios. This is a very clear, neat, and 
elegant performance; nevertheless some 
persons, even among those ,w'ho 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, sive Cosrao- 
theoria puerilis,’’ written by Baxter, author 
of the “Inquiry into the Nature of the 
Human Soul and the year after he print- 
ed 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 meantime Robins’s performances 
were not confined to mathematical sub- 
jects ; 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 
Q q 2 
