New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1856-01-31

Atlantic slope, III d uttt ulstahcc hoAA WY N'
has the same quantity to the 35th parallel ony'
thus showing our heaviest rainfall 70 be In the III
terror and that it quite reyerses the European rule
of distribution in this respect. This quantity oil
water shows that the system of drainage is required
70 lie on gigantic scale, and that the present de-
feiencv of levees and guards might have been ex-
pected. when estimates of the quantity were as
INADEQUATE as the recently one OF thirty
six inches for this Valley in the latitude OF the
| Ohio.
From Cincinnati and Central Iowa the quanti-
ties fall off rapidly, however, and more surpris-
irgly than elsewhere. At the Great Lakes, the
annual mean fall is but thirty inches. At Fort
Smelling it falls nearly to % inches and on the
high prairie region it is at this quantity nearly TO
the one hundredth meridian. 1t also falls of re-
markedly on the mountains of Pennsy lvania and
Virginia, again reversing the European analogles'
On these mountains and in their valleys there tails
but thirty-fve to thirty-seyen inches while the
Atlantic Coast aud Ohio Valley, on either hand,
have forty.two 10 fOrty-seven. All the rivers OF
the southern portion ofthe Aleghanes are deficient
in their supply of water or deficient in regardt its
permanence at least, as compared with those fur
| Their north and east.
In this last direction, and over the elevated dis
tf,ts OF NewYork, with all its eastern portion and
New.Engand, except the valley of Lake Cham
plain, the quantity is large, and uniform at from
forty to forty-fse inches. There appears to be
little contrast caused by differences OF altitude, and
tie proximity of the Atlantic evidently causes the
excess over the same ATTITUDES of the Lake dis
trict. the rule of distribution differing from that
belonging to the ATTITUDES below the fortieth para
lei. The uniformity in the positive measures of
forty-two to forty-fye degrees, which belongs to
the Atlantic States from Washington to Maine is
a noticeable fact in connection with the great
diversity elsewhere.
The deficiency in the Lake District appears to
be explained BY reference to the distribution for
Spring and Summer, and to he due to their cooling
effect on the air at those seasons, which does not
prevent the excessive saturation and heavy falls OF
rain which occur elsewhere On the immediate
coast of the Atlantic and the Gulf of Mexico the
same results obtain and the annual mean is dimin-
shed five inches by this cause at Nantucket eight
CT ten On the coast islands near Savannah and much
mere at Key West and in parts of the Gulf of
Mexico.
The great interior area of deficient rain reaches
from the 9sth to the 123d meridian, embracing The
Plains, Western Texas, the Rocky Mountain pla-
teaux, and the Great Basin districts, with most OF
California. Between the Rocky Mountains and
Sierra Nevada and Cascade ranges on the west,
the whole country is homogeneous; and though
, the Colorado and Columbia rivers have outlets to
the sea. yet they receive little addition to their
volume after leaving the mountains; and the guam
tity of rain on the great plains they traverse is
similar to that of the Great Basin. The only point
positively known is at Fort Yuma, which has but
three inches yearly for the mean of four years; no
part of this area can have mean of more than ten
inches for the year.
The Rocky Mountain districts are only partially
Known Fort Laramie and the posts of New
Mexico giving some measures But the fact that
vast deserts lie all along the oftest plateaux of the
northern portion, on Jefferson's Fork of the Mis-
souri,, on the sources Of Snake River, and of the
Platte the Colorado, and the Rio Grande proves
that it would be unwarranted to assign this general
district more than twenty five to thirty inches when
Fort Laramie and other posts only reach ten to
twenty. Taking the number of months in which
STOW falls its partially known depths, and the
average drainage of this vast region by the shallow
rivers of The Plains and the three only which
deboueh west and south, We must regard the
whole mountain region as cOnspicuously arid, COM
pared with the mountains of New-York and New
England, aud as probably having little more than
half their quantity of rain.
In the south of New.Me1ico we touch upon the
region of Summer rains; but we lose more in
Spring and Winter than is added in Summer, and
the degree of ardty is much greater in consequence
of the exchange of seasons and the absence of
ecu III distributed rains.
The Pacific Coast is peculiar, and it blends the
characteristics Of Italy and Norway The Southern
Alps and other points in the vicinity of the Med-
terranesn have the Autumn rainy season, or the
| Winter rainy season of two branches, separated by
a comparatively dry interval in January and Feb.
ruarv: ard the California coast has the same. BY
gradual transition, going north from San Fran
cisco, the excessive and continuous Winter rains
of Norway become instituted, and they characterize
all the coast Of Oregon and YancOuyers Island.
The quantity at Astoria is not less than sixty
inches; and east of the first coast-range of noun
tans, at Fort Vancouver and Olympia, it is still
fifty inches. In California, which has many of the
characteristics Of Italy, the annual quantity of rain
varies from ten inches st San Diego to twenty-five
at San Francisco
The Mississippi Valley is most anomalous in its
| 81 III tha into