STR 
Formation of the Earth, has given an ac- 
count of many diti'erent kinds of animals, 
wliose shells and other remains, or exiivim, 
are found in England ; though at present 
the living animals are not to be found, ex- 
cept in the East or West Indies. Nothing 
has more perplexed tliose who undertake to 
form theories of the earth than these ap- 
pearances. Some have at once boldly as- 
serted, from these apd other phenomena, 
that the world is eternal. Others have had 
recourse to the universal deluge. Some, 
♦mong whom is the Count de BuflFon, en- 
deavour to prove that the ocean and dry 
land are perpetually changing places ; that 
for many ages (he highest mountains have 
been covered with water, in consequence 
of which the marine animals just mentioned 
were generated in such vast quantities; 
that the waters will again cover these moun- 
tains, the habitable part of the earth be- 
come sea, and the sea become dry land as 
before, &c. Others have imagined, that 
they might be occasioned by volcanoes,^ 
earthquakes, &c. which confound the dif- 
ferent strata, and often iptermix the pro- 
ductions of the sea with those of the dry 
land. 
STRATIOTES, in botany, a genus of 
the Dioecia Dodecandria class and order. 
Natural order of Palm®. Hydrocharides, 
Jussieu. Essential character ; spa the two- 
leaved; perianth superior, trifid; petals 
three; beriy six-celled. There are three 
species. The stratiotes, water aloe, or wa- 
ter soldier, is a stoloniferous plant, and 
truly perennial, though each root flowers 
but once, as in some species of saxifraga, 
sempervivum, &c, The parent plgnt, root- 
ed in the mud at the bottom of the ditch, 
after floweying, sends out buds of leaves at 
the end of long runners, which rise to the 
surface, form roots, flower, and then sink 
to the bottom, where they take hold of the 
mud, sometimes ripen their seeds, and al- 
ways become in their turn the parents of 
another race of young offsets. 
STRELITZIA, in botany, so named in 
honour of Charlotte, Queen of Great Bri- 
tain, of the family of Mecklenburgh Stre- 
litz, an illustrious patroness of the science 
of botany, a genus of the Pentandria Mo- 
nogynia class and order, Natural order of 
Scitamine®, Mus®, Jussieu. Essential 
character : spathes universal and partial ; 
calyx none; corolla thvee-petalled ; nec- 
tary tiuee-leaved, involving the gentials; 
capsule three-celled ; cells many-seeded. 
There are two species, viz. S, regiij®, canna- 
STR 
leaved strelitzia, and S. augusta. Tiiesa 
plants are natives of the Cape of Good 
Hope ; they were introduced and named 
by Sir Joseph Banks. 
STRENGTH, in physiology, the same 
with force. 
Men may apply their strength several 
ways in working a machine. A man of or- 
dinary strength, turning a roller by the 
handle, can act for a Whole day against a 
resistance equal to thirty pounds weight; 
and if he w'orks ten hours a day, he will 
raise a weight of thirty pounds through 
three feet and a half in a second of time ; 
or if the weight be greater, he will raise it 
so much less in proportion. But a man 
may act, for a small time, against a resist- 
ance of fifty pounds or more. If two men 
work at a windlass, or roller, they can more 
easily draw up severity pounds, than one 
man can thirty pounds, provided the elbow 
of one of the handles be at right angles to 
that of the other. And with a fly, or heavy 
wheel, applied to it, a man may do one- 
third part more work; and for a little 
white he can act with a force' or overcome 
a continual resistance, of eighty pounds ; and 
work a whole day when the resistance is but 
forty pounds. Men used to bear loads, such 
as porters, will carry, some one hundred and 
fifty pounds, others two hundred or two 
hundred and fifty pounds, according to 
their strength. A man can draw but about 
seventy or eighty pounds horizontally ; for 
he can but apply about half his weight. If 
the weight of a man be one hundred and 
forty pounds, he can act with no greater 
force in thrusting horizontally, at the height 
of his shoulders, than twenty seven pounds. 
As to horses : a horse is, generally speak- 
ing, as strong as live men. A horse will 
carry two hundred and forty or two hun- 
dred and, seventy pounds. A horse draws 
to greatest advantage when the line of di- 
rection is a little elevated above the hori- 
zon, and the power acts against his breast ; 
and he can draw two hundred pounds for 
eight hours a day, at two miles and a half 
an hour. If he draw two hundred and forty 
pounds, he can work but six hours, and not 
go quite so fast. And in both cases, if he 
carries some weight, he will draw the bet- 
ter for it. And this is the weight a horse is 
supposed to be able to draw over a pulley 
out of a well, But in a cart, a hoise may 
draw one thousand pounds, or even double 
that weight, or a ton weight, or more. As 
the most force a horse can exert, is when 
he draws a little above the horizontal posi- 
