Virginia Argus. [volume] (Richmond, Va.) 1796-1816, 1810-02-27
[forr D7aars Per Aaaaa- Paid in Aavauoe.

OF the interior parts Sf- the globe is
much greater than those near the sur
face, and that probably towards the.
centre of the earth, there is matter
whose specific gravity as far exceeds
the heaviest metal known as that Of
the latter does the lightest gas. For
it the whole globe was composed of
(platina, whose specific gravity is 20 !.
336, the moon must necessarily con-
sist of some substance, the specific
Egravity of which would only be the 4 :.
IL of water. But as it is not probable,
the specific gravity of the moon is
less than that of water, the Interior
I, parts OF the earth must have a speci-
6c gravity of at least twelve times that
of plstina.
Wsh respect to the theory of Ber-
hardin de Saint Pierre, although it has
been much ridiculed, yet the waters of
the ocean are affected in greater de.
gree, by the causes which he assigns,
than by any ofthe celestial bodies.
| Part of de Saint P.erre's theory is
founded upon facts, and not upon hv-
pothesis. tits established by thetes-
simony of the most respectable navi-
gators, and by thousands of seamen.
that the p5lar regions are frozen for
SIX m enths in the year to the 10Th de-
gree OF latitude, and daring the sum
mer months a diurnal melting of the
Ice takes place. Ii is also known, that
the nearer we approach the poles the
more ,the ice is elevated above the
water. The elfusions from the poles
in this season, will therefore, Increase
the waters of the ocean.
De- Saint Pierre has not calculated
or given lis any data To calculate the
daily increase arising from this cause,
or the time necessary for the water
proceed ng from the ice to arrive The
lequator. lie only suPposes that suf.
lhcispt guam ity Of water flows from the
lpelar gions to produce the phenome-
ma of the tides.
/ Sir Isaac Newton erred precisely
IN the same respect. He assumed az
a truth, that the moon was Of such a
density as to cause the tides. and ther.
from the height of the tides he call
culated the density OF the moon.
THIS modeof reasoning ought always,
Impossible, to be avoided. The de !.
Egree of power which the cause posses
ses, ought frat TO be known and then
the eHect may be calculated unless
1t can be demon stated, that the effect
IN question is alone produced bv the
supposed cause. If Sir Isaac Newton
had previously demonstrated, that the
tides were the sole consequence of the
attractive forces of the sun and the
moon, then his theory would have
been correct, and he would have been
Justified IN the conclusion which he has
drawn Of the density of the moon.
In like manner, if De Ssint Pierre had
shewn US, that the illusions. of water
from the polar ice were the sole agents
in raising the tides, he would have
been warranted in all the conclusions
which he has made; but as this is not
done, we are not toreceive his theory
in its full extentor 10 believe that these
diurnal illusions are the sole cause of
raising the waters Of the ocean.
But as 1t is evident they constitute
one of the causes. let us endeavor, If
possible, to ascertain in direct man
ner the quantity Office melted every
twenty-foar hours, and the velocity Of
the water thence arising towards the
equator. Then it may be possible TO
caiculate with some degree of accura.
cy, the effect produced upon the
tides.
am well aware, that this is a pro-
blem ofthe greatest difficulty, and one
the solution of which, we can q. Is hone
for in the most distant approx nation.
Yet it may be sufficient to assist the
present investigation and to satisfy us
of the impossibllity Of the tides icing
solely produced by tie water aowine
from the poles.
From mean ofthe several accounts
Of the most respectable navigators, the
maximum of the frozen part of the
polar region extends to 7O7 OF
latitude, and the minimum to SOC
that is, in the northern hemis.
phere about the 21st of March, the O
cean round the north pole is frozen TO
roo