EMERSON. 
at present it comes to ns only from South 
America. Vauquelin found it to contain of 
silex 64.5, argil 16, glucine 13, oxide of 
chrome 3.25, lime 1.6, and water 2, The 
oriental emerald is a green corundum, or 
resplendent lustre, superior in hardness to 
every stone but the diamond, and of the 
specific gravity of 4. 
EMERSION, in astronomy, is when any 
planet that is eclipsed begins to emerge or 
get out of the shadow of the eclipsing body. 
It is also used when a star, before hidden by 
the sun as being too near him, begins to re- 
appear or emerge out of his rays. 
EMERSON (William), in biography, 
a late eminent mathematician, was born in 
June, 1701, at Hurworth, a village about 
three miles south of Darlington, on the bor- 
ders of the county of Durham ; at least it 
is certain that he resided here from his 
childhood. His father, Dudley Emerson, 
taught a school, and was tolerably profi- 
cient in mathematics; and, without his 
books and instructions, perhaps his son's 
genius, though eminently fitted for mathe- 
matical studies, might never have been un- 
folded. Beside his father’s instructions, 
our author was assisted in the learned lan- 
guages by a young clergyman, then curate of 
Hurworth, who w as boarded at his father’s 
house. In the early part of his life he at- 
tempted to teach a few scholars ; but whe- 
ther from his concise method, for he was 
not happy in explaining his ideas, or the 
warmth of his natural temper, lie made no 
progress in his school ; he therefore soon 
left it off, and, satisfied with a moderate 
competence left him by his parents, he de- 
voted himself to a studious retirement, 
which he thus closely pursued, in the same 
place, through the course of a long life, be- 
ing mostly very healthy, till towards the 
latter part of his days, when he was much 
afflicted with the stone. About the close 
of the year 1781, being sensible of his 
approaching dissolution, he disposed of 
his whole mathematical library to a book- 
seller at York; and on May the 20th, 
1782, his lingering and painful disorder put 
an end to his life, at his native village, being 
nearly 81 years of age. 
Mr. Emerson, in his person, was rather 
short, but strong and well made, with an 
open countenance and ruddy complexion, 
being of a healthy and hardy disposition ; 
he was very singular in his behaviour, 
dress, and conversation ; his manner and 
appearance were that of a rude and rather 
boorish countryman ; he was of very plain 
conversation, and seemingly rude, com- 
monly mixing oaths in his sentences, though 
without any ill intention ; he had strong 
good natural mental parts, and could dis- 
course sensibly on any subject, but was al- 
ways positive and impatient of contradic- 
tion ; he spent his whole life in close study, 
and writing books, from the profits of which 
he redeemed his little patrimony from some 
original incumbrance ; in his dress he was 
as singular as in every thing else ; he pos- 
sessed commonly but one suit of cloaths at 
a time, and those very old in their appear- 
ance ; he seldom used a waistcoat ; and his 
coat he Wore open before, except the lower 
button ; and his shirt quite the reverse of 
one in common use, the hind side turned 
foremost, to cover his breast, and buttoned 
close at the collar behind ; he wore a kind 
of rusty coloured wig, without a crooked 
hair in it, which probably had never been 
tortured with a comb from the time of its 
being made ; a hat he would make to last 
him the best part of a life-time, gradually 
lessening the flaps, bit by bit, as it lost its 
elasticity and hung down, till little or no- 
thing but the crown remained. 
He often walked up to London when he 
had any book to be published, revising 
sheet bv sheet himself : trusting no eye but 
his own, was always a favourite maxim with 
him. In mechanical subjects, he always 
tried the propositions practically, making 
all the different parts himself on a small 
, scale ; so that his house was filled with all 
kinds of mechanical ■'instruments, together 
or disjointed. He would frequently stand 
up to his middle in water while fishing, a 
diversion he was remarkably fond of. He 
used to study incessantly for some time, 
and then for relaxation take a ramble to 
any pot ale ; house where he could get any 
body to drink with, and talk to. The late 
Mr. Montague was very kind to Mr. Emer- 
son, and often visited him, being pleased 
with his conversation, and used frequently 
to come to him in the fields where he was 
working, and accompany him home, but 
could never persuade him to get into a car- 
riage : on these occasions he would some- 
times exclaim, “ Damn your whim-wham ! 
I had rather walk.” He was a married 
man, and his wife used to spin on an old- 
fashioned wheel, of his own making, a draw- 
ing of which is given in his “ Mechanics.” 
Mr. Emerson, from his strong, vigorous 
mind and close application, had acquired 
deep knowledge of all the branches of ma- 
thematics and physics, upon all parts of 
