The enquirer. [volume] (Richmond, Va.) 1804-1815, 1809-12-26

aud one hour in the morning the difference
OF the velocities is as. 052 to I.
He next proceeds to discover the effects
which this difference ct velocity IN opposite
points ct the sau,e parallel OF latitude, pro
duces upon the matter Of the globe. and the
faids which surround it in every diurnal ro
ta,on. Ii is first demonstrated that from
this difference of velocity; bodies at the e.
quator 1T one hour +. NJ. are lighter than at
|
one hcur after midnight by - of their
9375
weight; that is, body which at one hour
!P: M, would weigh 1874 pounds, At one hour
after midnight, would weigh 9S75 pounds
|" The effect (he says) which this difference
in the gravi,; of bodies produces upon the
matter and auds on the surface of the globe
is SOC times greater than the cffsc, produ
cet'by the attraction of the moon, aud 1872
times greater than any effect produced by
the sun; for Sir Isaac Newton has demon
st,atcd (Prop. 81. Book Sd. princip) that
the force OF the moon is to the force of gr.i-
witty as to 2S31400; and the force of the
sun to that otgravi.y as to 1236S200. Bat
the effect produced by the difference Of We.
lloctiss in Opposite points is to the force OF
gravity as ! to 9575; wherefore il is SOC
times greater than the effect produced bv
the moon and 1872 times greater than tie
effect produced by the srS." From this fact
it is demonstrated, that any eject produced
by either the moon q; fhe sun up N the fluids
which encompass the globe, is so tritiing as
no. tobe perCeptibjc to tho senses, or even
ny accurate experiments.
! II he following remarkable conclusion is
also drawn by the author from this fact, viz.
that the density Of the earth is $50 times
that Of the MOON For (he savs) Sir Isaac
Newton has demonstrated in Cor. 8, Prop.
81. Book 3d. that supposing the force of the
inooa to he such as TO raise the tide IS feet
at Bristol, her density would be to that of
, the earth as IL to9. Bur since IL has been
shewn that toe waters of the ocean are ac-
ted apon by a force sos times greaTer than
that of the moon; therefore the density OF
the mnon is - of what Sir Isaac Newton
500
supposed; or the density OF the earth is to
that of the moon as 9 to or as $50 to1
This immense difference between the aensi-
ty OF the earth and that of her satellite, ma
turally draws US to another conclusion, viz.
that the density cs the interior parts of the
globe is much greater than those near the
surface, and that probably towards the cen
tire of the earth, there is matter whose spe-
icifc gravity as far exceeds the heaviest me-
tai known as that OF the latter does the light
est gas. For if the whole globe was compo
sed of patina. whose specific gravity is 20
1856. the moan must necessarily conss, OF
some substance, the specific gravity of which
would only be the -o of water. But as it is
not probable, the specific gravity of the
moon is less than that of water, the intevior
parts of the earth must have specific gra
witty of at least 10 times that of platina.'
The third book is divided into three chap
tiers. The LIST chapter explains the eff Cts
of the eycloidal motion of the earth upon the
Atmosphere. The following article con-
tains the general result Of the Investigation
g From the pressure of the atmosphere,
supporting 4 perpendicular pillar Of quick
silver, between % and 81 inches high ; it
has been calculated that the pressure of the
atmosphere on the surface ofthe whole earth
is equal to about 116430l9S4COOOOOC
pounds. But since it has been demonstrated,
that the atmosphere is expanded into the
form of spheroid by the rotation of the
earth about its axis, OF which the greater
diameter is in the direction of the centre of
the earth and the sun, it follows that the
waters of the ocean must be more pressed at
six hours before noon ard six hours after
noon, than AT any other period OF the twenty
/, four, because then tbs least expanded or den
sese parts of the atmosphere press upon the
cartii,
! This excess of pressure, at six hours be-
| fore noon, and six hours afternoon, will cause
the waters to rise at those places which are
ninety degrees of longitude from those parts
| of the Globe that have sis. hours A. NJ. or
| six hours p. Nj; or which amounts to the
same thing, the waters will be higher at
noon and midnight, owing to the pressure Of
the atmosphere, tran at any other time.
The particular height to which the water
will rise, owing to the unequal pressure of
! the air. can only be calculated by the Baro-
meter with any accuracy. i have stated,
that General Roy first observed. that the
mercury in the Barometer was always lowest
at noon and at midnight The mean of this
diurnal variation in the mercury has been
estimated at inch, or about the - of the
| 60
column Of quicksilver. Therefore as it is
known. that the pressure of the atmosphere
is equal to IS feet OF water, it follows, that
the waters at noon and at midnight, owing
to the unequal pressure of the air which
surrounds the globe, ought to be the - of
90
! SO feet, or 81 inches higher than at 6 A.
Nj. or p. M"
The trade winds and othe r phenomena of
the atmosphere, are explained in the same
chapter, upon the principle OF the cycloidal
melton Of the earth.
In chapter I'd, all the phenomena of the
| tides investiu ted at con Siderable lenatI,