# Simson, Robert

, an eminent mathematician, was the eldest son of Mr. John Simson, of Kirton-hall in Ayrshire, and was born Oct. 14, 1687. Being intended for the church, he was sent to the university of Glasgow in 1701, where he made great progress in classical learning and the sciences, and also contracted a fondness for the study of geometry, although at this time, from a temporary cause, no mathematical lectures were given in the college. Having procured a copy of Euclid’s Elements, with the aid only of a few preliminary explanations from some more advanced students, he soon came to understand them, and laid the foundation of his future eminence. He did not, however, neglect the other sciences then taught in college, but in proceeding through the regular course of academic study, acquired that variety of knowledge which was visible in his conversation throughout life. In the mean time his reputation as a mathematician became so high, that in 1710, when only twenty-two years of age, themembersof the college voluntarily made him an offer of the mathematical chair, in which a vacancy in a short time was expected to take place. From his natural modesty, however, he felt much reluctance, at so early an age to advance abruptly from the state of a student, to that of a professor in the same college, and therefore solicited permission to spend | one year at least in London. Being indulged in this, he proceeded to the metropolis, and there diligently employed himself in improving his mathematical knowledge. He also enjoyed the opportunity of forming an acquaintance with some eminent mathematicians of that day, particularly Mr. Jones, Mr. Caswell, Dr. Jurin, and Mr. Ditton. With the latter, indeed, who was then mathematical master of Christ’s Hospital, and well esteemed for his learning, &c. he was more particularly connected. It appears from Mr. Simson’s own account, in his letter, dated London, Nov. 1710, that he expected to have had an assistant in his studies chosen by Mr. Caswell; but, from some mistake, it was omitted, and Mr. Simson himself applied to Mr. Ditton. He went to him not as a scholar (his own words), but to have general information and advice about his mathematical studies. Mr. Caswell afterwards mentioned to Mr. Simson that he meant to have procured Mr. Jones’s assistance, if he had not been engaged.

When the vacancy in the professorship of mathematics at Glasgow did occur, in the following year, by the resignation of Dr. Robert Sinclair, or Sinclare (a descendant or other relative probably of Mr. George Sinclare, who died in that office in 1696), the university, while Mr. Simson was still in London, appointed him to fill it; and the minute of election, which is dated March 11, 1711, concluded with this very proper condition, “That they will admit the said Mr. Robert Simson, providing always, that he give satisfactory proof of his skill in mathematics, previous to his admission.” He returned to Glasgow before the ensuing session of the college, and having gone through the form of a trial, by resolving a geometrical problem proposed to him, and also by giving “a satisfactory specimen of his skill in mathematics, and dexterity in reaching geometry and algebra;” having produced also respectable certificates of his knowledge of the science, from Mr. Caswell and others, he was duly admitted professor of mathematics, on the 20th of November of that year.

Mr. Simson, immediately after his admission, entered on the duties of his office; and his first occupation necessarily was the arrangement of a proper course of instruction for the students who attended his lectures, in two distinct classes. Accordingly he prepared elementary sketches of some branches on which there were not suitable treatises in general use. Both from a sense of duty and from | inclination, he now directed the whole of his attention to the study of mathematics; and though he had a decided preference for geometry, which continued through life, yet he did not devote himself to it to the exclusion of the other branches of mathematical science, in most of which there is sufficient evidence of his being well skilled. From 1711, he continued near fifty years to teach mathematics to two separate classes, at different hours, five days in the week, during a continued session of seven months. His manner of teaching was uncommonly clear and successful; and among his scholars, several rose to distinction as mathematicians; among which may be mentioned the celebrated names of Dr. Matthew Stewart, professor of mathematics at Edinburgh; the two Rev. Dr. Williamsons, one of whom succeeded Dr. Simson at Glasgow; the Rev. Dr. Trail, formerly professor of mathematics at Aberdeen; Dr. James Moor, Greek professor at Glasgow: and professor Robison, of Edinburgh, with many others of distinguished merit. In 17.58, Dr. Simson, being then seventy-one years of age, found it necessary to employ an assistant in teaching; and in 1761, on his recommendation, the Rev. Dr. Williamson was appointed his assistant and successor.

During the remaining ten years of his life, he enjoyed a pretty equal share of good health; and continued to occupy himself in correcting and arranging some of his mathematical papers, and occasionally for amusement, in the solution of problems, and demonstration of theorems, which occurred from his own studies, or from the suggestions of others. His conversation on mathematical and other subjects continued to be clear and accurate; yet he had some strong impressions of the decline of his memory, of which he frequently complained; and this probably protracted, and finally prevented his undertaking the publication of some of his works, which were in so advanced a state, that with little trouble they might have been completed 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 2d edition of the Elements. But from that period, though much solicited to bring forward some of his other works on the ancient geometry, though he knew well how much it was desired, and though he was fully apprised of the universal curiosity excited respecting his discovery of Euclid’s Por-> isms, he resisted every importunity on the subject. | A life like Dr. Simson’s, purely academical and perfectly uniform, seldom contains occurrences, the recording of which could be either interesting or useful. But his mathematical labours and inventions form the important part of his character; and with respect to them, there are abundant materials of information in his printed works; and some circumstances also may be gathered from a number of ms papers which he left; and which, by the direction of his executor, are deposited in the library of the college of Glasgow. It is to be regretted, that, of the extensive correspondence which he carried on through life, with many distinguished mathematicians, a small portion only is preserved. Through Dr. Jurin, then Secretary of the Royal Society, he had some intercourse with Dr. Halley, and other distinguished members of that Society. And both about the same time, and afterwards, he had frequent correspondence with Mr. Maciaurin, with Mr. James Stirling, Dr. James Moor, Dr. Matthew Stewart, Dr. Wm. Trail, and Mr. Williamson of Lisbon. In the latter part of his life, his mathematical correspondence was chiefly with that eminent geometer the late earl Stanhope, and with George Lewis Scott, esq.

As to his character, Dr. Simson was originally possessed of great intellectual powers, an accurate and distinguishing understanding, an inventive genius, and a retentive memory: and these powers, being excited by an ardent curiosity, produced a singular capacity for investigating the truths of mathematical science. By such talents, with a correct taste, formed by the study of the Greek geometers, he was also peculiarly qualified for communicating his knowledge, both in his lectures and in his writings, with perspicuity and elegance. He was at the same time modest and unassuming; and. though not indifferent to literary fame, he was cautious, and even reserved, in bringing forward his own discoveries, but always ready to do justice to the merits and inventions of others. Though his powers of investigation, in the early part of life, were admirable, yet befoiv any decline of his health appeared, he felt strong impressions of the decay both of his memory and other faculties; occasioned probably by the continued exertion of his mind, in those severe studies, which for a number of years he pursued with unremitting ardour.

Besides his mathematical attainments, from his liberal education he acquired a considerable knowledge of other | sciences, which he preserved through life, by occasional reading, and, in some degree, by his constant intercourse with many learned men in his college. He was esteemed a good classical scholar; and, though the simplicity of geometrical demonstration does not admit of much variety of style, yet in his works a good taste in that respect may be distinguished. In his Latin prefaces also, in which there is some history and discussion, the purity of language has been generally approved. It is to be regretted, indeed, that he had not had an opportunity of employing, in early life, his Greek and mathematical learning, in giving an edition of Pappus in the original language.

Dr. Simson never was married; and the uniform regularity of a long life, spent within the walls of his college, naturally produced fixed and peculiar habits, which, however, with the sincerity of his manners, were unoffending, and became even interesting to those with whom he lived. The strictness of these habits, which indeed pervaded all his occupations, probably had an influence also on the direction and success of some of his scientific pursuits. His hours of study, of amusement, and of exercise, were all regulated with uniform precision. The walks even in the squares or garden of the college were all measured by his steps, and he took his exercises by the hundreds of paces, according to his time or inclination.

It has been mentioned, that an ardent curiosity was an eminent feature in his character. It contributed essentially to his success in the mathematical investigations, and it displayed itself in the small and even trifling occurrences of common life. Almost every object and event excited it, and suggested some problem which he was impatient to resolve. This disposition, when opposed, as it often necessarily was, to his natural modesty, and to the formal civility of his manners, occasionally produced an embarrassment, which was amusing to his friends, and sometimes a little distressing to himself.

In his disposition, Dr. Simson was both cheerful and sociable; and his conversation, when he was at ease among his friends, was animated and various, enriched with much anecdote, especially of the literary kind, but always unaffected. It was enlivened also by a certain degree of natural humour; and even the slight fits of absence, to which in company he was occasionally liable, contributed to the entertainment of his friends, without diminishing their | affection and respect, which his excellent qualities were calculated to inspire. One evening (Friday) in the week he devoted to c!nb, chiefly of his own selection, which met in a tavern in-ar the college. The first p; rr of the evening was employed in playing the game o which he was particularly fond; but, though he tool all trouble in estimatng chances, it was remarki h;it he was often Uimh ces ml. The rest of the evening ua> spent in cheerful conversation and, as he had some taste for music, he did not scruple to amuse his party with a song and it is said that he was rather fond of singing some Greek odes, to which modern music had been adapted. On Saturdays he usually dined in the village of Anderston, then about a mile distant from Glasgow, with some oi tie members of his regular club, and with a variety of 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 character, it became the wish of his company that every thing in these meetings should be directed by him; and though his authority, growing with his years, was somewhat absolute, yet the good humour with which it was administered, rendered it pleasing to even body He had his own chair and place at table; he gave instructions about the entertainment, regulated the time of break.ng up, and adjusted the expense. These parties, in the years of his severe study, were a desirable and useful relaxation to his mind, and they continued to amuse him till within a few months of his death.

Strict integrity and private worth, with corresponding purity of morals, gave the highest value to a character, which, from other qualities and attainments, was much respected and esteemed. On all occasions, even in the gayest hours of social intercourse, the doctor maintained a constant attention to propriety. He had serious and just impressions of religion; but he was uniformly reserved in expressing particular opinions about it; and, from his sentiments of decorum, he never introduced religion as a subject of conversation in mixed society, and all attempts to do so in his lubs were checked with gravity and decision.

In his person, Dr. Sunson was tall and erect; and his countetance, which was handsome, conveyed a pleasing expression of the superior character of his mind. His manner had always somewhat of the fashion which prevailed in the early part of his life, but was uncommonly graceful. | He was seriously indisposed only for a few weeks before his death, and through a very long life had enjoyed a uniform state of good health. He died October I, 1768, when his eighty-first year was almost completed; having bequeathed his small paternal estate in Ayrshire to the eldest son of his next brother, probably of his brother Thomas, who was professor of medicine in the university of St Andrew’s, and who is known by some works of reputation, particularly a “Dissertation on the Nervous System, occasioned by the Dissection of a Brain completely Ossified.”

The writings and publications of Dr. Simson were almost exclusively of the pure geometrical kind, after the genuine manner of the ancients. He has only two pieces printed in the volumes of the Philosophical Transactions: viz.

1. Two general propositions of Pappus, in which many
of Euclid’s Porisms are included, vol. Xxxij. ann. 1723.
These two propositions were afterwards incorporated into
the author’s large posthumous works, published by earl
Stanhope. 2. On the Extraction of the Approximate
Roots of Numbers by Infinite Series, vol.XLVIII. ann. 1753.
The separate publications in his life-time, were, 3. “Conic Sections,” 1735, 4to. 4. “The Loci Plani of Apollonius, restored,” 1749, 4to. 5. “Euclid’s Elements,”
1756, 4to, of which there have been since many editions
in octavo, with the additions of Euclid’s Data. In 1776,
earl Stanhope printed, at his own expence, several of Dr.
Simson’s posthumous pieces: 1. Apollonius’s determinate
section. 2. A treatise on Porisms. 3. A tract on Logarithms. 4. On the limits of quantities and ratios; and, 5.
Some geometrical problems. Besides these. Dr. Simson’s
Mss. contained a great variety of geometrical propositions
and other interesting observations on different parts of the
mathematics: though not in a state fit for publication.
Among other designs, was an edition of the works of Pappus, in a state of considerable advancement, and which,
had he lived, he might perhaps have published. What he
wrote is in the library of the college of Glasgow, and a
transcript was obtained by the delegates of the Clarendon
press. ^{1}

^{1}

Account of the Life and Writings of Robert Simson, M. D. by the Rev. William Trail, LL. D. F. R. S. Edm. M.R. I. A. and chancellor of St. Saviour’s Connor, 1812, 4to, abridged by Dr. —Hutton in the new edit, of his Dictionary. Encyclop. Britan.