642 
PLAY 
therefore, have been no ordinary meafure of ability that 
called forth the following ingenuous avowal, in a confiden¬ 
tial letter to his mother: “ Playfair has very great merit, 
and more knowledge and a better judgment than any of his 
clafs-fellows. I make no exceptions; my parts might be 
more (howy, and the kind of reading to which my inclina¬ 
tion led me was calculated to enable me to make a better 
figure at St. Andrew’s; but in judgment and underftanding 
I was greatly inferior to him.” (Dr. Cook’s Life of Princi¬ 
pal Hill.) It is fcarcely a ftronger, though undoubtedly a 
very different, proof of his rare attainments, that when 
the profefforof natural philofophy, Wilkie, the once-ce¬ 
lebrated author of the Epigoniad, was prevented by indif- 
pofition from delivering the regular lectures, heufed ge¬ 
nerally to delegate the talk of inftru&ion to Playfair. 
In 1766, when only eighteen years of age, he offered 
himfelf, with the approbation of his inftruffors at St. 
Andrew’s, as candidate for the Profefforfhip of Mathema¬ 
tics in Marefchal College, Aberdeen ; and fuftained, with 
the moft diftinguifhed credit, an examination or compa¬ 
rative trial, which lafted eleven days, and embraced 
nearly the whole range of the exa< 5 t fciences. Out of the 
fix competitors who entered the lifts againft him, two 
only were judged to have excelled him; the Rev. Dr. 
Trail, who was appointed to the office, and Dr. Hamilton, 
who afterwards fucceeded, and has long filled it with much 
reputation. In 1769 he removed to Edinburgh, where 
his merit and modefty very foon introduced him to the 
friendfhip of Dr. Robertfon, Adam Smith, Dr. Matthew 
Stewart, Dr. Black, and Dr. Hutton ; with all of whom 
he continued in terms of the utmoft cordiality during 
the whole period of their lives. In 1772, he was a 
candidate for the profefforfhip of natural philofophy at 
St. Andrew’s, vacant by the death of his friend Dr. Wil¬ 
kie. There was no comparative trial on this occafion ; 
and he was again unfuccefsful, under circumftances which 
led Dr. Cook to remark, “ how much the univerfity fuf- 
fered in thus lofmg a man, by whofe talents its reputa¬ 
tion would have been fo highly promoted.” 
In the courfe of the fame year, the death of his father 
fuddenly devolved upon him the burden of fupporting 
the family, and admonifhed him no longer to delay the 
final election of a profefiion. He had been educated with 
a view to the church, and was every way qualified to 
accept a livingon the eftablifhment; but his decided pre¬ 
dilection for fcience had hitherto made him hefitate about 
engaging in a vocation, the duties of which, he felt, if 
confcientioufly difcharged, would neceffarily interfere, 
to a great extent, with the ftudies he was loth to aban¬ 
don. In this emergency, however, he thought himfelf 
no longer entitled to indulge in thofe predilections ; and, 
accordingly, made application to lord Gray, the patron, 
for a prefentation to the livings of Liff and Benvie, which 
had been filled by his father. His lordfhip immediately 
iffued a prefentation in his favour, although, from fome 
challenge of his right to the patronage, induction was not 
obtained till late in the year 1773. 
From this period, till 1782, Mr. Playfair was conftantly 
refident at Liff, and occupied almoft exclufively with the 
paftoral duties of his office. In this retreat his leifure 
hours were dedicated to the education of his younger 
brothers, and to a very clofe and intimate correfpondence 
with Mr. Robertfon (now lord Robertfon), the fon of 
the illuftrious hiftorian, to whom he feems to have con¬ 
fided the remarks that occurred to him upon the different 
authors he perufed,and the fubjefts of (peculation which 
they fuggefted. We cannot help hoping, that fome fe- 
leftion from this correfpondence may one day be given to 
the public. In the year 1779 he contributed to the Phil. 
Tranf. a paper “On the Arithmetic of Impoflible Quan¬ 
tities,” which exhibits, within a very fmall compafs, a 
ftriking example of the rare and admirable talent of de¬ 
taching the (ound fpirit of fcience from what may be 
termed its myfticifm, and circumfcribing, by the moft 
precife and luminous boundaries, the vague and unli- 
F A I R. 
mited inquiries into which many mathematicians had 
been feduced by the nature of the inftruments they em¬ 
ployed. 
In the year 1782 he was induced, by very advantageous 
offers, to refign his charge, and to fuperintend the edu¬ 
cation of Mr. Fergufon of Raith, and his brother, Sir 
Ronald; an arrangement which reftored him, in a great 
meafure, to the literary and fcientific fociety of Edin¬ 
burgh, and enabled him to gratify himfelf by a perl'onal 
introduction to feveral of the moft eminent cultivators of 
fcience in London. He had repeatedly vifited Dr. Mafke- 
lyne, aftronomer royal, while that ingenious mathemati¬ 
cian was bufied, in 1774, in making a feries of obferva- 
tions in Perthlhire on the attraction of mountains; and, 
while (haring the (helter of his tent on the fide of Sche- 
hallien, contracted with him a cordial friendlhip, which 
continued unbroken for the remainder of their lives. 
Under thefe honourable aufpices, he made his firft ap¬ 
pearance in London in 1782, and was fpeedily introduced 
to all thofe in whom he was likely to take moft intereft. 
He feems to have kept a pretty full and correCt journal 
of all that he obferved during this journey to the metro¬ 
polis ; and a portion of it, which is prefixed to the late 
collection of his works, is, in our judgment, one of the 
moft interefting parts of that publication. 
In 1785, he was received into the Univerfity of Edin¬ 
burgh, in confequence of an arrangement between his 
two illuftrious affociates, Dr. Adam Fergufon and Mr. 
Dugald Stewart. Mr. Stewart exchanged the chair of 
Mathematics, in which he had fucceeded to his father, 
for that of Moral Philofophy, which had been long filled 
by Dr. Fergufon; who, finding that the delicate ftate of 
his health w'ould prevent him from difcharging the aCtive 
duties of the mathematical profeffor, immediately de¬ 
volved them upon Mr. Playfair, for whom he procured 
the appointment of joint profeffor in that department. 
In 1788 he publi(hed,in the Tranf. of the R. S. of Edin¬ 
burgh, “ A Biographical Account of Dr. Matthew Stew¬ 
art,” which is remarkable, not only for the eafe and pu¬ 
rity of the ftyle, but alfo for containing a Angularly clear 
and interefting account of the labours of Dr. Simfon in 
the reftoration of the ancient geometry, and of the fuc- 
cefs both of him and Dr. Stewart in adapting the elegant 
fimplicity of the Greek methods of inveftigation to pro¬ 
blems which had previoufly been regarded as infoluble 
except by the aid of the modern analyfis. He alfo pub- 
lifhed, in the fame year, a paper “ On the Caufes which 
affeCt the Accuracy of Barometrical Meafurements,” 
which is written with all the perfpicuity, caution, and. 
fagacity, that conftitute the great excellence and the 
great difficulty of fuch difquifitions, where fcientific 
principles are employed to give precifion to phyfical ob- 
fervations. 
In 1790 he publiflied in the fame Tranfaftions a paper 
of (till greater intereft and delicacy, “ On the Aftronomy 
of the Brahmins;” a fubjedt which had been recently re¬ 
commended to the notice of the European fcientific world 
by the curious and learned obfervations of M. Bailley, in 
his General Hiftory of Aftronomy, but had never met 
with fo minute and fcrupulous an inveftigation as it now 
received at the hands of Mr. Playfair. This was followed 
in 1794 by a learned and very beautiful treatife “ On the 
Origin and Inveftigation of Porifms,” in which the ob- 
fcure nature of the very comprehenfive and indefinite the¬ 
orems to which this name was applied by the ancient geo¬ 
meters, is explained with the moft lucid fimplicity, and 
the extraordinary merits of Dr. Simfon, in deducing their 
true theory from the very vague and (canty notices of 
them which had come down to his time, are commemo¬ 
rated with a noble fpirit of emulation. 
In 1795 he publilhed his “Elements of Geometry,” 
for the ufe of the pupils attending his clafs; a work 
which has fince been held in fuch eftimation by the pub. 
lie as to have gone through five editions, four of which 
were called for fince the work ceaied to be ufed as a clafs- 
2 book 
