, 1874-02-21
THE EARTH MOVES,
atmospheric Proofs Of Rotation.
Why Everything Moves Towards the
Right.

Frn0sltl0Q Uuu14uE 4Al l4S1eS q ILL 24A I'LL
nistakablo proof that the earth rotates. Grand
r. amule in its construction and movement,
hat ball of lead tells the story of world.motion
nth mute eloquenco which cannot bo equaled
hr the most fervid uttcrances Of highly gifted
orstor. But the simple pendulum is far from
ha;,c the only demonstration Of the truth On
which, ss q phyFica1 axiom, are built up most Of
the exterior phenomena Of our matcria az
istence
The movements Of the atmosphere are at
,nce effects and proofs OF the fact
that tie earth turns on her axis daily.
John uadlcy stated nearly century and
half ago {.735). that the trade winds Of
tbe tropics arc duo to the heating power Of tho
rnn mud the earth's rotation. But 1t is only
few years since it VAS discovered that the atmos-
rherlc movements at every point on the earth's
surface arc duo to the operation OF the same
rn,ses, combined with minor ones.
TEE TRADE WINDS.
The heating effect Of the suns rayH is
greatest at those places to which he is
nlaccs becomes heated by radiation from
fho earth, increases in volume in consequence.
md rises to the upper regions OF the atmos-
Dlcre. The area OF greatest heat and rarefac-
tion follows the SUMS apparent motion from
east to west, on circle OF latitude correspond
inq to the suns declination. Tho air from tho
north and south OF this line moves towards it
u restore tue equilibrium Of pressure. is heated
in it's turn, and carried upward its place being
snnplicl by other air that comes from points
nearer the poles.
current is thus established from every dircc-
t;on towards the rapidly shifting area over which
tho sun is vertical. But each particle OF this
cu,rent WAS originally moving eastward with the
velocity Of that point on the surface over which
it yas at relative rest. The
rtrE or Tf1IB EASTWARD MOVEMENT
In onlr changed slowly by mingling with other
volumes of air, or friction with the surface.
Hence. asit approaches the equator, where the
eastward velocity OF the surface is greater, the
mir lars behind just MS the pendulum falls back
on tho circumference Of our circle on the hoor.
This relative westward movement. compounded
with that towards the place OF the sun, Causes
the air that proceeds from the north to blow
towards tho southwest: and that which proceeds
frou the south blows towards the northwest.
The rccula,itvs Of the trade-wind system is
somewhat interfered with by the fact that
land and water are not equally. heated
b. similar exposure to the. the solar o fa!, fay1,
Of the middle line between the tropics. In mid
SIMMER aud nlidwinter the wind betveeh the
piacc Of the sun and the equator travels east
ward more rapidly than the surface over which
it blows. ...- .-
OUR PREVAILING WINDS.
The air that is carried up under the place OF
the sun lin the belt of equatorial cainls) flows
o7er in the upper regions OF the atmosphere
ind turns towards the poles, descending to tho
scouired the equatorial velocity b. moving III the
regions near tho equator, aud hence moves cast
ward more rapidly than tie surface over
which it blows IS it proceeds towards
tho pole. Hence, the prevailing motion on
Of the air in the United States, and the whole OF
weet to the northeast. 1t is from northwest
10 southcast in the South Temperate Zono
sTonMs
a.e caused by inte1uptionB in the regularity OF
tho movements above noted- Owing 10 Tue IN
texpositiou of clouds, the suns rays may warm
a portiou OF the eartn's surface more thnn tho
surrounding region, aud the air that ID above It
rises. The surrounding mir then moves to"aros
the partial vacuum, to restore the pressure.
But there is good reason to believe tnat :air our
Of cold. A volume Of air, that contains
considerable quantity OF the Vapor
of water III suspension, IS moving IN
obedience to the law already noted: In passing
over the cold to? Of mountain It becomes SUI
denly chilled and its capacity for sustaining Va-
por is greatly reduced in consequence Its y, "a
Dor ia Condensed, aud falls as rain or SHOW. The
pressure OF the air at that place is thus
ty tile weight OF the deposited moisture and the
air is further reduced in volume ~ the cold;
We have then an ''area of low barometer
which moves eastward. or northcastward. rs the
air volume was moving before 1T encountered me
mountain, and the alr from al around tt1a
1sarca" moves towards it to fill the partial Tolu
The storms OF this region originate Ill the Aoexs
Mountains, and, doubtless, i'll this way.
TIE CYCLONE.
The rotation Of the Garth ca1lEes tue WIND TO
blow around the area Of low barometer lnstcau
Of directly towards it. The reason for this phe-
nomenon is apparent from glance at the &C.
companying diagram
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