106 PHYSICAL GEOGRAPHY.

 

Rainfall in the Temperate Zone.

 

EUROPE.

Inches. Inches.
Madeira. ............+++0+029.82 | Southern France........ 23.54
Sicilyno iit aoncisisencees 23.55 | Southern Germany.....26.64
W. side of Apennines..35.17 | Netherlands .............. 26.70
E. ef ee ..26.70 | British Islands, Plain..27.00
Sere eo SAI DSio. Sieeee 57.87 ff i Mts....50.00
N. MS Pacskessccests 35.27 | W. Coast Scandinavia..82.12

Mean Rainfall in Europe in the Temperate
LONG sccrssceeaetccwesueseecses mi Sacwmaneaaweasstertsnnestese 34 inches.

AMERICA.
Inches
Rey. West, Bloridaiveccc.csves21s veccetnocsstcesisascceseseccats 35.26

  
 
 
  
   

Charleston, S. C....... --47.60
Washington, D. C.. ‘

Marietta, Ohio.........
West Chester, Penna...
Cambridge, Mass......

 

 

600 ins. ==

500 “

400 “

  
 

301 ins.
300 “

200 “

  

 

100 « OES ins.

 

 

 

 

82 ins.

 

 

 

 

 

 

 

 

 

Burlington, Vt... 39.44

Eastport, Maine... 36.28

New York.... Sea cceecertatts Siincitccereteee ncsoeesaes 36.28

Mean Rainfall in the United States in the
Temperate Zone, ....ccasccssssecssacsesscsssecssenedes 89 inches.
46.9 ins. 38 ins. 32 ins. nee

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

Cherrapon- Mahabulesh- Vera
gi, India. war, India, Cruz.

Fig, 93. Comparative Rainfall,

St.Do- Bergen, Philadelphia, Cambridge, British Alexandria,
mingo. Norway. Penna, Mass. Isles. Egypt.

(Lhe figures represent the annual rainfall in inches.)

278. Rainless Districts—In some parts of the
world, rain is either entirely absent, or falls only
in limited quantities, at long intervals. The most
extensive rainless districts are found in the east-
ern continent.

Desert Belt of the Eastern Continent—From
the western shores of Northern Africa eastward
to the Great Kinghan Mountains in Asia, extends
an almost uninterrupted belt of desert lands. It
includes the great desert of the Sahara, the Ara-
bian and Persian Deserts, and the Desert of Mon-
golia. The aridity is most absolute in the west,
where, in the Sahara and in the desert of Arabia,
rain seldom, if ever, falls. Toward the east, in
Persia and Mongolia, scanty rains occur, but the
country has the appearance of a desert.

The cause of this:immense desert tract is to be
found in the dry trade winds, which blow over
most of the region. Having previously crossed
the vast continent of Asia as upper currents, they
arrive at the deserts dry and vaporless. Even

that portion of the region which receives the
winds from the Mediterranean has no rainfall,
because any clouds that may form, are soon dis-
sipated by the hot air of the desert.

Persia and Mongolia owe their deserts to their

high mountain borders, which rob the clouds of
their moisture before they cross the interior pla-
teaus. The high system of the Himalayas effect-
ually prevents any of the moisture of the south-
west currents from penetrating the plateau of
Mongolia.

Arid tracts occur in the Kalahari desert, in Africa, and
near the tropic of Capricorn, in Australia.

Desert Belt of the Western Continent.—The
desert lands of the Western Continent are more
contracted in area. In North America, the largest
desert is in the Great Interior Plateau. Here the
mountain borders, especially the Sierra Nevada
on the west, deprive the interior of rain. The
aridity is not absolute, since scanty rains occur
over parts of the region. Portions of the penin.
sula of California and of the Mexican Plateau
also resemble deserts.

In South America, on the western slopes of the
Andes, between the parallels of 27° and 23°S.,
is found the desert of Atacama. Here rain never
falls, although the ground is oceasionally refreshed
by mists'and dews. The cause of the absence of
rain is to be traced to the high Andes, which con-
dense all the moisture of the trades on their east-