35i
From 1711 he continued for nearly half a century to
teach mathematics to two separate classes, at different
hours, for five days in the week, during a continued
session of seven months. His lectures were given
with such perspicuity of method and language, and
his demonstrations were so clear and successful, that
among his scholars several rose to distinction as
mathematicians; among whom may be mentioned
the celebrated names of Colin Maclaurin, Dr.
Matthew Stewart, professor of mathematics at Edin-
burgh ; the two Rev. Drs. Williamson, one of whom
succeeded Dr. Simson at Glasgow; the Rev. Dr.
Trail, formerly professor of mathematics at Aber-
deen; Dr. James Moor, Greek professor at Glas-
gow; and Professor Robison of Edinburgh, with
many others of distinguished merit.
In 1758 Dr. Simson, having arrived at the ad-
vanced age of seventy-one years, found it expedient
to employ an assistant in teaching; and in 1761, on
his recommendation, the Rev. Dr. Williamson was
made his assistant and successor. For the last re-
maining ten years of his life he enjoyed a share of
good health, and was chiefly occupied in correcting
and arranging some of his mathematical papers; and
sometimes, for amusement, in the solution of problems
and demonstrations of theorems which had occurred
from his own studies, or from the suggestions of
others. Though to those most familiar with him
his conversation on every subject seemed clear and
accurate, yet he frequently complained of the decline
of his memory, which no doubt protracted and even-
tually prevented him from undertaking the publica-
tion of many of his works, which were in an ad-
vanced state, and might with little exertion be made
ready for the press. So that his only publication,
after resigning his office, was a new and improved
edition of Euclid's Data, which, in 1762, was annexed
to the second edition of the Elements. From that
period he firmly resisted all solicitations to bring
forward any of his other works on ancient geometry,
though he was well aware how much it was desired
from the universal curiosity excited respecting his
discovery of Euclid's Porisms. It is a matter of re-
gret, that out of the extensive correspondence which
he carried on through life with many distinguished
mathematicians, a very limited portion only is pre-
served. Through Dr. Jurin, then secretary to the
Royal Society, he had some intercourse with Dr.
Halley and other celebrated men; he had also fre-
quent correspondence with Mr. Maclaurin, with Mr.
James Stirling, Dr. James Moor, Dr. Matthew
Stewart, Dr. William Trail, and Mr. Williamson of
Lisbon. In the latter part of his life his mathe-
matical correspondence was chiefly with that eminent
geometer the Earl of Stanhope, and with George
Lewis Scott, Esq.
A life like Dr. Simson's, so uniform and regular,
spent for the most part within the walls of a college,
affords but little that is entertaining for the bio-
grapher. His mathematical researches and inven-
tions form the important part of his history; and,
with reference to these, there are abundant materials
to be found in his printed works and MSS., which
latter, by the direction of his executor, are deposited
in the college of Glasgow.
Dr. Simson never was married; he devoted his
life purely to scientific pursuits. His hours of study,
of exercise, and amusement were all regulated with
the most unerring precision. "The very walks in
the squares or gardens of the college were all mea-
sured by his steps; and he took his exercises by the
hundred of paces, according to his time or inclina-
tion." His disposition was by no means of a satur-
nine cast: when in company with his friends his con-
versation was remarkably animated, enriched with
much anecdote, and enlivened also by a certain
degree of natural humour ; even the slight fits of
absence to which he was sometimes liable contri-
buted to the amusement of those around him, with-
out in the slightest degree diminishing their affection
and reverence which his noble qualities were calcu-
lated to inspire. At a tavern in the neighbourhood
of his college he established a club, the members of
which were, for the most part, selected by himself.
They met once a week (Friday); and the first part
of the evening was devoted to the game of whist,
of which Dr. Simson was particularly fond ; but
though he took some pains in estimating chances, it
was remarked that he was by no means fortunate in
his play. The rest of the evening was spent in
social conversation; and as he had naturally a good
taste for music, he did not scruple to amuse his com-
pany with a song: and, it is said, he was rather fond
of singing some Greek odes, to which modern music
had been adapted. On Saturdays he usually dined
at the village of Anderston, then about a mile dis-
tant from Glasgow, with some of the members of
his regular club, and with other respectable visitors,
who wished to cultivate the acquaintance and enjoy
the society of so eminent a person. In the progress
of time, from his age and high character, the com-
pany respectfully wished that everything in these
meetings should be directed by him; and although
his authority was somewhat absolute, yet the good
humour and urbanity with which it was administered
rendered it pleasing to everybody. He had his own
chair and particular place at the table; he ordered
the entertainment, adjusted the expense, and regu-
lated the time for breaking up. These happy parties,
in the years of his severe application to study, were
useful relaxations to his mind, and they continued to
amuse him till within a few months of his death. A
mind so richly endowed by nature and education,
and a life of strict integrity and pure moral worth,
gave a correspondent dignity to his character, that
even in the gayest hours of social intercourse the
doctor's presence was a sufficient guarantee for atten-
tion and decorum. He had serious and just impres-
sions of religion, but he was uniformly reserved in ex-
pressing particular opinions about it: he never intro-
duced that solemn subject in mixed society; and all
attempts to do so in his clubs were checked with
gravity and decision. His personal appearance was
highly prepossessing; tall and erect in his carriage,
with a countenance decidedly handsome, and convey-
ing a pleasing expression of the superior character of
his mind. His manner was somewhat tinged with the
fashion which prevailed in the early part of his life,
but was exceedingly graceful. He enjoyed a uni-
form state of good health, and was only severely
indisposed for a few weeks before his death, which
took place on the 1st of October, 1768, in his eighty-
first year. He bequeathed a small paternal estate in
Ayrshire to the eldest son of his next brother, pro-
bably his brother Thomas, who was professor of
medicine in the university of St. Andrews, and who
was known by some works of reputation.
"The writings and publications of Dr. Robert Sim-
son were almost exclusively of the pure geometrical
kind, after the genuine manner of the ancients; but
from his liberal education he acquired a considerable
knowledge of other sciences, which he preserved
through life, from occasional study and a constant
intercourse with some of the most learned men of
the age. In the Latin prefaces prefixed to his
works, in which there are some history and discus-
sion, the purity of the language has been generally
approved." And many scholars have regretted that