The record-union., 1894-05-19
INCREASING RAINFALL.
Construction of Railroads Altered
Electrical Conditions.
How Irrigation and the Planting of
Trees Have Increased the
Rainfall.

more attention than any other statistical
statement of climatic conditions that can
be issued. AS much depends upon the
distribution of the rain in the various
weeks of the year as uponl the total
amount that may fall in any given sea-
son. Heavy rainfall in December. jan
uary and February, and light rains or
none at all after the lst of April are Oh 1T
tie benefit, while light rains from NoVem-
Der, at intervals of few days, up to the
middle of June, make an ideal year for
the agriculturist. Due TO conditions.
which are not necessary here to relate,
the rains of California occur principally
in the three winter months.
The rainfall is heaviest in Del Norte
and Humboldt Counties on the north.
from which it gradually decreases in
amount along the Immediate coast to San
Diego IN the south; in the interior it is
heaviest in Siskiyou and Shasta Counties,
whence it gradually decreases to San
Diego County. The amount of rainfall
along the coast is from seventy-seven
inches in Del Norte County to eleven
inches in San Diego County; in the in
terror from forty inches in S1skiyou to
five inches in the eastern part of San
Diego County. From line drawn east
and west through the southern line OF
Sacramento County, northward, the rain
fall in California is twenty inches or
more; south of such line it is less than
twenty inches. Twenty inches of rainfall
in any year or season is ample for all pur-
poses for vegetation when such an amount
is well distributed through the various
months, especially in the months when
= vegetation is maturing, from April to
July. Over the section of California
, h. nfC to laCe n
twenty inches in any year or season. or
where it is badly distributed, /. e.. when
practically no rain falls from March to
July, then irrigation Is necessary to in
sure the successful growth OF vegetation,
be it cereal or fruit.
There is saI large portion Of California
where all conditions are favorable for the
production of any product known to the
temperate zone, and for many articles of
the tropic or semi-tropIc zone, save the
absence of rainfall. This deficiency is
overcome by the extensive irrigation
bitches and the consequent supply of
water for supplying that which nature
has failed to do. In years OF drought. as
the present, even the irrigation ditch is
guarded most jealously.
This prelude leads up to the question,
is there no way to help or assist nature
To furnish man with water in the shape
OF moisture from the clouds. Within the
memory of the present generation COM
mon school biographies spoke of and
contained on the maps of the United
States what was then termed the "Great
American Desert" This desert has
passed away. The questions then are,
Has the rainfall increased? What condi-
tions have arisen TO change the so-called
desert 2"
First it should be known the section
defined as desert was not in reality a
desert as the term is technically and gen.
orally understood. The semi-desert con-
ditions which prevail have been overcome
by the advent of railroads, settlements,
cultivation of the soil, planting OF trees,
and last, but not least, by irrigation.
These are the causes which changed the
"desert" into one of the most fertile sec
tons of the United States and which will
materially reduce the difficulty of ma
ture's deficient supply of moisture, espe-
cially IN dry or drought years in Cali
fernia.
The engineers in charge of the Mexi-
can Central Railway reported that in the
building of the road it was noted that
with the coming OF the construction train,
bearing great quantities of steel rails, that
the rain fell in advance of the train at un-
usual times and in unusual quantities. 1t
can be assured that by the construction OF
railways the electrical conditions of the
country are disturbed that have an in
huence upon the precipitation. The cul-
tivation of the soil allows of the moisture
which falls TO be absorbed by the soil,
rather than allowing it to run off as is the
case in hard and unwOrked soils, hence a
greater amount OF moisture is present,
which evaporation produces higher per-
centage of moisture in the air; the food
for a storm is heat and moisture. hence
the influence Of the cultivation Of the soil
is facilitating the deposit of moisture.
The planting of trees serves a twofold
purpose in this connection. The leaf sur
face OF the tree is very great, when the
aggregate is considered, hence can be
seen the great amount OF increased
humidity obtained from the moisture
which is thrown off by the leaves; sec
ondly, the roots Of trees serve as sponge,
when taken in connection with the soil
surrounding the roots, which serves TO
absorb and retain moisture and to allow
its gradual escape to springs, thus afford
ing more constant supply 10 thestreams,
preventing their drying up and affording
a greater amount OF moisture to the at
moSphere. The various systems of irri-
CATION, distributing Emoisture to soil,
which in turn Is absorbed by the vegeta-
ton and finally evaporated, furnishes a
most satisfactory means of making the
air more humid and OF making the con-
ditions more favorable for possible rain
fall. All of these conditions combined
add very greatly to the moisture of the
air. hence food for the storm, and facili-
tates the posi- bility OF rain when without
these artificial means rainfall would be
practically impossible.
Hence it may be considered that the
opening up Of the land to tIIlage, plant
ing OF trees, the building of railroads and
general covering OF many square miles
in vegetation that were formerly barren
wastes, have a tendency to retain the
moisture from the clouds, and this in turn
renders the air more humid, so that there
is an actual increase in the moisture oi
the air beneficial to vegetation. In this
connection the following from the United
States Department of Agriculture, For
estry Division, Bulletin No. 7, will prove
of interest:
uThere is one region deficient in rain
fall and water supply for which claims
in behalf of an actual or possible increase
OF rainfall due to human agency are less
often made, but which the preceding an
alvsis leads me TO believe would not be
unreasonable TO anticipate. refer TO the
San Joaquin Valley Of California. This
valley is fianked by the Coast Range on
the west and by the Sierras on the east.
The moisture eVaporated from the sur
face cannot escape from the basin, but
Will be largely precipitated either over
the valley or on the sides OF adjacent
0OuuldllS, Wnlcn cOHStilute It's NAteI-
shed. Ii, therefore, the increase in irri-
CATION and in the extent of cultivated
area produces material increase in the
evaporation, 1t seems reasonable to ex-
pect that this moisture will be restored
by an increased rainfall in the valley and
on the adjacent mountain sides. One
consideration only would appear to re-
tard and diminish this effect. The inclos-
ure of the valley prevents that rapid in
draught of air which renders possible q
rapid vertical circulation. Thus the ac-
tivity of the whole process is rendered
sluggish, and the total amount of moist
ure passing through the cycle from evap-