STEWART. 
household, except such as belong to the 
chapel, chamber, and stable. 
There is also a Steward of the Marshal- 
sea, who has judicial authority. And in most 
corporations, and all houses of quality in 
the kingdom, there is an otBcer of the name 
and authority of a steward. 
The steward of a ship is he who receives 
all the victuals from the purser, and is to 
see it well stowed in the hold ; all things of 
that nature belonging to the ship’s use are 
in his custody ; he looks after tlie bread, 
and distributes out the several messes of 
victuals in the ship ; he hath an apartment 
for himself in the hold, which is called the 
steward’s room. 
STEWART (the Rev. Dr. Matthew), 
in biography, late professor of mathematics in 
the University of Edinburgh, was the son of 
the Rev. Mr. Diigald Stewart, minister of 
Rothsay, in the Isle of Bute, and was born 
at that place in the year 1717. After hav- 
ing finished his course at the grammar 
school, being intended by his father for the 
church, he was sent to the University of 
Glasgow, and was entered there as a stu- 
dent in 1734. His academical studies were 
prosecuted with diligence and success ; and 
he was so happy as to be particufarly dis- 
tinguished by the friendship of Dr. Hutche- 
son, and Dr. Simson the celebrated geome- 
trician, under whom he made great progress 
in that science. 
Mr. Stewart’s views made it necessary 
for him to attend the lectures in the Uni- 
versity of Edinburgh in 1741 ; and that his 
mathematical studies might suffer no inter- 
ruption, he was introduced by Dr. Simson 
to Mr. Maclaurin, who was then teaching 
both the geometry and the philosophy of 
Newton, and under whom Mr. Stewart 
made that proficiency which was to be ex- 
pected from the abilities of such a pupil, 
directed by those of so great a master. 
But the modern analysis, even when thus 
powerfully recommended, was nOt able to 
withdraw his attention from the relish of 
the ancient geometi-y, which he had im- 
bibed under Dr. Simson. He still kept up 
a regular correspondence with tlfis gentle- 
man, giving him an account of his progress, 
and of his discoveries in geometry, which 
were now both numerous and important, 
and receiving in return many curious com- 
munications with respect to the Loci Plani, 
and the Porisms of Euclid. Mr. Stewart 
pursued this latter subject in a different and 
new direction. In doing so, he was led to 
the discovery of certain curious and inte< 
resting propositions, which he published un- 
der the title of “ General Theorems,” in 
1746. They were given without the de- 
monstrations ; but they did not fail to place 
their discoverer at once among the geome- 
tricians of the first rank. They are, for 
the most part, Porisms, though Mr. Stew- 
art, careful not to anticipate the discoveries 
of his friend, gave them only the name of 
Theorems. They are among the most beau- 
tifiil, as M'ell as most general propositions, 
known in the whole compass of geometry, 
and are perhaps only equalled by the re- 
raaikable locus to the circle in the second 
book of Apollonius, or by the celebrated 
theorem of Mr. Cotes. 
In September, 1747, he was elected pro- 
fessor of mathematics in the University of 
Edinburgh. The duties of this office gave 
a turn somewhat different to his mathema- 
tical pursuits, and led him to think of the 
most simple and elegant means of explain- 
ing those difficult propositions, which were 
hitherto only accessible to men deeply 
versed in the modern analysis. In doing 
this, he was pursuing the object which, of 
all others, he most ardently v/ished to at- 
tain, viz. the application of geometry to 
such problems as the algebraic calculus 
alone had been thought able to resolve. 
His solution of Jiepler’s problem was the 
first specimen of this kind which he gave to 
the world. This is founded on a general 
property of curves, which, though very 
simple, had perhaps never been observed ; 
and by a most ingenious application of that 
property, he shows how the approximation 
may be continued to any degree of’accu- 
racy, in a series of results which converge 
with great rapidity. 
This solution appeared in the second vo- 
lume of the Essays of the Philosophicpd So- 
ciety of Edinburgh, for the year 1756. In 
the first volume of the same collection, 
there are some other propositions of Mr 
Stewart’s, which are an extension of a cu- 
rious theorem in the fourth book of Pappus. 
They have a relation to the subject of Po- 
risms, and one of them forms the ninety-first 
of Dr. Simsou’s Restoration. 
He next published the “ Tracts, Physical 
and Mathematical.” In the first of these, 
Mr. Stewart lays down the doctrine of cen- 
tripetal forces, in a series of propositions, 
demonstrated (if we admit the quadrature 
of curves) with the utmost rigour, and re- 
quiring no previous knowledge of the ma- 
thematics, except the elements of plane 
geometry, aud of coaic sections. The good 
