Virginia Argus. [volume] (Richmond, Va.) 1796-1816, 1810-02-27
mfebmouu 1erire Garrent.
IcoRREcrED WEExLY.l

4 OolcCO, , %
Wheaf, neSv, / II
Floar, szbc,-fne, 6 SO
sF7ouy, fas, 6 90
Corn, 8 So
z4emb, pc, ton, $50 90
.lron, ITO 10
Bacon 90 90
Whis6ey 90 &C
E.stract fran Mr.. J. WooD's yery IN :
gehious Book, lately published in this
city, entitled" Il new Theory ofthe
Dmraal Rotation Of the Earth," SIC.
According to the theory of Sir l.
: saac Newton, the tides ought to be
higher in the torrid zone than in the
temperate zones; but according to the
observation of Dampier, which I have
related, the waters only rise in the
torrid zose, between ole and two
feet, Sir. Isaac Newton attempts to
account for the tides not being so high
between Africa and Am erica, because
the ocean is narrower tlsau in the tenn
perate, zones or either side and he
farther adds, that in the Pacific ocean,
between the tropics, which issofa grea
ter depth, as we'll as of a larger extent,
the tides are greater than in the At
lantlc ocean without the tropics. In
this, however, he is mistaken, and he
has doubtless been misiniormed with
respect to the tides in the Pacific ocean,
for the principal navig ,tors agree,
that every where in the to.rid zone the
tides are remarkably low, between A.
STA and America as well as between
Africa and America.
Sir Isaac Newton slvs, in the begin
ming of Prop. 9th, Book 3d. tha,
the greatest height of the waters in the
open and deep seas ought to follow the
appulse of the luniDariesto the meri-
dian of the place By a less interval than
SIX hours; as happens in all that cas-
tern tract OF the Atlantic and Eihiopic
seas bcrwcsn France and the Cape oil
Good Hope and on the coasts of Chill
and Peru in the south sea-" But those
Observations in different places, which
4 have copied from Robertson, prove
that Sir Isaac Newton theory, IN this
respect, is erroneous. For at he Maze
of Norway, which is quite exposed TO
the open ocean, high water happens E.
leveD hours and fifteen minutes after
the appuise of the moon to ,he meridi-
an. At Cape Clear, Irslsnd, it takes
place nine hours and fifty minutes af-
ter be moons p .ssage and in like
manner with many Of the other places
which l have quoted, all exposed to
the opon sea, where the time Of high
water neither corresponds with the
theory, and what is still more extraor.
dinary, there appears TO be no regular
difference between the hour of high
water at one place, and that at ano-
Their, according to the degree OF lati-
tude.
The most positive proof that the
moon does not influence the tides, is
the second proposition of the 2d book
OF this essay, where have demonstra-
ted, that the effect produced by the cy-
cloidal motion Of the earth is 3O6 times
greater than that of the moon where
fore. allowing this motion TO be the
sole cause Of raising the tides, and that
the highest tide, according to the OBJ
servasion of Samuel Sturmv at Bristol,
is 45 feet or $40 inches, the increase
produced by the moon cannot exceed
Il "A inch, which in lower tides would
not be discernable.
A very obvious corolIary presents
itself from knowledge of this fact.
which may lead to discoveries Of the
greatest Importance in the several
branches Of physics. 1t is this, tina,
the densityof the earth is $50 times
that OF the moon. For Sir Isaac New
ton has demonstrated in Cor, 8, Prop.
81, Book lid, that supposing the
force OF the moon to be such as 10
raise the tide As feet at Bristol. her
density would be to that OF the earth
as 1 to 9. But have shewn that
the waters ofthe orsan are acted upon
BY force SOC times greater than that
OF the moon therefore the density of
the moon is 1906 Of what Sir Isaac
Newton supported or the density OF
the earth IS to that of the moon as 9
to 1906 or as $50 to 1