The morning star and Catholic messenger. [volume] (New Orleans [La.]) 1868-1881, 1877-05-06
khMAkKAB. RESULT or ETAPOhA
IIUN AND RAINFALL.

| above the ocean level ~ erroneous. Land
10 above the level of the sea Ouly where
| there il direct water ommuLlcation, by
| the drainage stFeans Of tue district, Will
the ocean. But there are many instances
| where such Communication does not
| exist; and IN such cases the drained surface
| may as well be- below as sbove the general
ocean level, where there are depressious 10
| the soil. Large regions that are below Toe
| ocean will not necessarily be entirely
| filed with water, because as RUE tue
amount Of evaporation far surpasses ehe
| amount of rainfall. To realize this fact, we
| have only to consider that one quarter OF the
terrestI ial surface ID land and tue rest water;
aud IL Is certain that the evaporation from
the land Cannot amount to much, compared
| with that from the aqueous surface. 1t Ia
true that vegetation throws some Watery
vapor into tho nj; but also ON the other hand
vegetation consumes great deal of water,
the elements of which are fixed in the
plants. We may assume, therefore, that
the evaporation from three quarters of the
tarth's surface, occupied oy ocean and
lax. 9, provides all the water falling on the
who're; therefore, as q rule, the evapora
ton from gwen surface of land surpasses
the amount vi rainfall. The former differs
for every climate, but it is for each special
belt OF latitude much more constant
quantity than the amount of rainfall,
which, by peculiar local circumsta noes,
cending from arid plains, ETC., is often 30
much Interfered with as to leave in some
places rainiess regions: such districts are
the southern extremity of California, aud
New Mexico, near the mouth of the Colora-
do river, aud there 10 another in the center
ofstbe Mexican Repu bic, aud still another
in a very elongated strip OF land with It's
eighboring sea extending along the west
ern coast OF South America, from Peru to
Chill. larger suriace of this kind Is
found in Central Asia, in aud around the
! deeert of Cobb or Shamu, situated i'll Mon
goiia and Chinese Tartary. But the largest
rainless surface ia that which extends IN
| Northern Africa, beginning some 300 miles
| inland from the western extremity, over a
width of not less than 600 miles in an
east by north direction. 1t covers large
part OF Egypt and the surrounding lands
including Arabia, and Harrow belt of
it passes through Asia and Persia. In the
last named country, a long strip of coun-
try, extending come 900 miles on each side
OF the 10Th meridian of longitude east of
| Greenwich separates it from the next lar
gest rainless region of Central Asia, men,
toned above.
On the other hand, there are few re-
gions of perpetual rain. These appear to
be, "a far as they are known, Cape Horn,
at the southern ex sremity of South Ameri
ca, and the neighborhood of Sitka, at the
southern part of Alaska Territory which
now forms part of the United States.
AT the western limits of the rainless re-
gion of Central Asia are situated several
lakes, receiving their water supply from
rivers; thess lakes are without communica-
ton with the ocean, but they are situated
on table land, some of them macy hun
dred feet above tho ocean level. But they
all dispose of their supply of water by
evaporation.
Every such locality forms n water sys-
tenn by its, If, surrou nded as it is on all
sides by mountain ran yes, without any
local depres sion to permiG the exit of water;
thus all, the rain received must necessarily
be disposed of by simple evaporation.
Westward from these lakes of Central
Asia, the elevation becomes less and less
until we reach the Sea OF Aral which is the
larEes of these inland seas, covering about
10000 square miles; It's surface has been
fonnd to ne only 81 feet above the level of
the ocean, while our Great Salt Lake in
Utah is not less than 220 feet above the
sea. Further west, the ground is still
more depressed, giving evidence that a
gradual sinking has taken place towards
the Shores of the Caspian Sea, which at it's
nearest point is scarcely 100 miles west of
the Sea of Aral, but of which the surface
is 10 feet below that of Aral, and S6 feet
below the level of the ocean. 1t is the
largest body of water in existence which
has no communication with the ocean. 1t
lie separated by high mountain chain from
Persia, q great portion of which empire lie
situated in the largest of the four or Ave
rainlees belts. This belt extends through
the whole of Central Africa aud South
western Asia, as far as the sources of the
river Indus. This sea, therefore, receives
no supply of water of any importance
from the soutI and on it's eastern side Onl y
one river OF any Importance empties itseli
: into it. This river is the Attruck. The
western shore receives the waters of sever.
| n rivere; but the northern eide receives an
a enormous amount of water from two large
r rivers, the V oiga and the Urai. The FIRST IL
4 the largest river of Europe, having length
of = 300 miles; 1t drains II face of not lest
, than GAO 600 square miles. more titan hal
the area drained by the Mississippi and The
= Missouri, and more than the whole of thu
watershed of the mighty st. Lawrence
, which with it's chain of large lakes drains
surface of 600, 900 square miles. The latte
!. river, the Ural, drains surface estimated
= to be nearly equal to that of the Caspian
n Sea. East of tue Ural, several Other con
4 siderable rivers, each about as large as on
a Hudson, Delaware, or Susquehanna, pou
| hpir vi oil in hA