PLAYFAIR. 
book in the Univerfity of Edinburgh. In 1797 he cotn- 
pofed a fequel to his firft paper on the Indian Aftronomy, 
in the fliape of “ Obfervations on the Trigonometrical 
Tables of the Brahmins;” and alfo a mafterly collection 
of “Theorems on the Figure of the Earth. 1 ’ It is alfo 
underftood that he occupied himfelf a good deal at this 
time in the preparation of an Effay “ On the Accidental 
Difcoveries made by Men of Science while in Purfuit of 
fome other ObjeCt although we find no portion of this 
curious difcufiion in the late collection of his works. 
His excellent and ingenious friend Dr. Hutton died in 
the year laft mentioned; and Mr. Playfair having under¬ 
taken to draw up a biographical account of him for the 
Royal Society, was firll led to Ifudy his ingenious, but 
fomewhat crude, fpeculations on the Theory of the Earth, 
and afterwards to lend them the afliltance of his own 
powerful pen in his “ Illuftrations of the Huttonian The¬ 
ory.” This work, on which he bellowed more time and 
labour than on any of his other productions, did not ap¬ 
pear till 1 Soz ; and it was not till 1803 that he prefented 
to their alfociates his admirable Memoir of their departed 
friend. The biographical account of Dr. Hutton is by far 
the belt of Mr. Playfair’s productions in this line; and 
contains not only an eloquent and luminous account of 
the fpeculations in which he was engaged, but what is 
too often forgotten in this fpecies of biography, a charm¬ 
ing portrait of the individual; drawn, no doubt, by a fa¬ 
vourable hand, but gaining far more in grace and effeCt 
than it can pofliblyhave loll in correCtnefs, from the foft- 
ening colours of aft’eCtion. 
. In 1805 he quitted the chair of Mathematics to fuc- 
ceed Profeffor Robifon in that of Natural Philofophy. In 
1807 he was eleCled a Fellow of the Royal Society of 
London, and foon after prefented to that learned body 
his “ Lithological Survey of Schehallien.” In 1809 he con¬ 
tributed to the Edinburgh TranfaCtions an excellent pa¬ 
per “ On Solids of the greatell Attraction ;” and, in 1812, 
another “ On the Progrefs of Heat in Spherical Bodies.” 
In 1814 he publilhed, in two volumes 8vo. for the ufe 
of his clafs, an elementary work of great value, under 
the title of “ Outlines of Natural Philofophy.” For fome 
years before this, he had been much oocupied in digeft- 
ing the plan and collecting the materials for a greatly en¬ 
larged edition of his “ Illuftrations of the Huttonian 
Theory;”, with a view to which, he had not only care¬ 
fully peruled and extracted a vail body of voyages and 
travels, but had made various journeys, and very mi¬ 
nutely examined almoftall the places in the Britifh domi¬ 
nions, the ftruCture of which promifed to throw any light 
on the fubjeCt of his refearches. No part of the work, 
however, w-as actually written, when the preparation for 
it was fufpended by his being induced to draw up for the 
Supplement to the Encyclopedia Britannica an introduc¬ 
tory “ Diflertation cn the Progrefs of Mathematical and 
Phyfical Science,” a treatife which, though its author had 
written nothing elfe, would itfelf fuffice to carry his name 
down with diftinCtion to pollerity. 
In 1815 he drew up for the Royal Society of Edin¬ 
burgh a very interefting Memoir of his diftinguifhed pre- 
decelTor Dr. John Robifon; a philofopher in wdiofe early 
life there was more adventure, and in his later days more 
political prejudice, than we ufually find to diverfify the 
hiftory of men of fcience. Nothing can be more fpirited 
and interefting than Mr. Playfair’s account of the former; 
nothing more manly and tender than his reluClant but 
decided proteftation againft the excefles of the latter. 
After the general peace, in 1815, had opened the con¬ 
tinent to Britifh inquirers, Mr. Playfair, at the age of 
fixty-eight, undertook a long journey through France and 
Swiflerland into Italy, and did not return for a period of 
nearly eighteen months. His principal attention was di¬ 
rected to the mineralogical and geological phenomena of 
the different regions which he vifited, and he made many 
notes with a view to the great objeCl which he was not 
deftined to accomplifh, namely, the extenfion and new- 
643 
modelling of his Illuftrations of the Huttonian Theory. 
On his return from this expedition, he employed himfelf 
chiefly in preparing the fecond part of the “ Diflertation” 
to which we have alluded ; and he alfo drew up a “ Me¬ 
moir on the Naval TaCtics of Mr. Clerk of Eldin,” which 
was publilhed after his death in the Phil.Tranf. His 
health had been occaiionally broken for feveral years by 
a painful afteCtion of the bladder, which appeared with in- 
creafed feverity in the early part of 1819, but was fo far 
got under as to enable him to complete his courfe of lec¬ 
tures in the fpring. It returned, however, in a Hill more 
diftrefling form in the fummer, and at laft put a period to 
his life on the 19th of July of that year. Though fuf- 
fering great pain during the laft part of his confinement, 
he retained not only his intelleClual faculties quite unim¬ 
paired, but the ferenity and miidnefs of his fpirits; and 
occupied himfelf till within a few days of his death in 
correCling the proof-flieets of the Diflertation, the print¬ 
ing of the fecond part of which had commenced fome 
time before his laft illnefs. Befides the Diflertation, Mr. 
Playfair contributed to the Ency. Suppl. the valuable bio¬ 
graphical account of Aspinus, and the Hill more valua¬ 
ble article on Phyfical Astronomy. Mr. Playfair was 
alfo, from the year 1804, a frequent contributor to the 
Edinburgh Review ; and there is perhaps no general ac¬ 
count of the great fafis and principles of aftronomy fo 
clear and comprehenfive as his account of La Place’s Me- 
canique Celefte, in the eleventh volume of the publica¬ 
tion juft mentioned. 
A Collection of Mr. Profeffor Playfair’s Works was 
publilhed at Edinburgh, in 4 vols. 8vo. 1822 ; and from 
the biographical account prefixed thereto we (hall make a 
few extraCls. “Mr. Playfair was one of the mod learned 
mathematicians of his age; and among the firft, if not 
the very firft, who introduced the beautiful difcoveries of 
the later continental geometers to the knowledge of his 
countrymen; and gave their juft value and true place, in 
the fcheme of European knowledge, to thofe important 
improvements by which the whole afpeCt of the abftraCt 
fciences has been renovated fince the days of our illuf- 
trious Newton. If he did not fignalize himfelf by any 
brilliant or original invention, he mull, at leaft, be al¬ 
lowed to have been a moll generous and intelligent 
judge of the achievements of others ; as weil as the n.< ft 
eloquent expounder of that great and magnificent fyltem 
of knowledge which has been gradually evolved by the 
fucceflive labours of fo many gifted individuals. He 
poflefled, indeed, in the higheft degree, all the charaCter- 
iftics both of a fine and a powerful underftanding; at 
once penetrating and vigilant, but more dillinguilhed, 
perhaps, for the caution and furenefs of its march, than 
for the brilliancy or rapidity of its movements, and 
guided and adorned through all its progrefs by the moll 
genuine enthufiafm for all that is grand, and the jufteft 
talle for all that is beautiful in the truth or the intellec¬ 
tual energy with which he was habitually converfant. 
“ Mr. Playfair, however, was not merely a teacher ; 
and has fortunately left behind him a variety of works, 
from which other generations may be enabled to judge 
of fome of thofe qualifications which fo powerfully re¬ 
commended and endeared him to his contemporaries. It 
is, perhaps, to be regretted, that fo much of his time, and 
fo large a proportion of his publications, fltould have been 
devoted to the fubjeCts of the Indian Aftronomy, and 
the Huttonian Theory of the Earth ; for, though nothing 
can be more beautiful or inftruCtive than his fpeculations 
on thofe curious topics, it cannot be diflembled that their 
refults are lefs conclufive and fatisfaClory than might 
have been defired, and that his doCtrines, from the very 
nature of the fubjeCts, are more queltionable than we be¬ 
lieve they could poflibly have been on any other topic in 
the whole circle of the fciences. To the firft, indeed, he 
came under the great difadvantage of being unacquainted 
with the Eaftern tongues, and without the means of judg¬ 
ing of the authenticity of the documents which he was 
obliged 
