482 REPORT OF THE COMMISSIGNER OF AGRICULTURE. 
chilled to the bone on crossing the Coast Range, and runs imminent risk 
of rheumatism or pneumonia. On the other hand, the San Franciscan, 
feeling the need of having his pores opened by a good perspiration, can 
have his wish gratified in an hour or two by taking the reverse direction. 
The ‘‘norther” is, of course, more frequent in the great valley than on 
the coast; but its dryness and high temperature are not so much of a 
change irom the ordinary condition of thing's, and it therefore does not 
cause such general remark, disturbance, or damage unless unusually 
severe. 
3. Climate of the slope of the Sierra Nevada.—The essential features 
of the climate of the Great Valley may be roughly said to extend to the 
height of about 2,000 feet up its flanks into the “ foot-hills,” with, how- 
ever, an increasing rainfall as we ascend, and therefore greater safety 
for crops and less absolute dependence upon irrigation. Higher up, 
the influence of elevation makes itself felt ; snow falls and lies in winter, 
while the summers are cool; and we thus return to the familiar régime 
of seasons as understcod in the Middie and Northern States, including, 
especially in the more northern portion, the phenomenon of summer 
thunder-storms, which are almost unknown on the coast and in the San 
Joaquin Vailey. The same general features come into play more and_ 
more as we advance northward in the hilly and mountainous regions 
lying north of San Francisco Bay, toward the Oregon line, marked also 
in general by a gradual increase of timber growth. The features of 
the three principal climates described intermingle, or are interspersed, 
according as the valleys are open to seaward, run parallel to the coast, 
or are in communication with the great interior valley. We thus find 
numberless local climates, ‘thermal belts,” and privileged nooks adapted 
to special cultures which may be impracticable in an adjoining valley, 
and almost insular as regards the region where similar conditions are 
predominant. ‘io the southward, the chief climates above defined are 
modified by three factors, viz: the increase of temperature, the decrease 
of rainfall, and the decrease, from about San Francisco southward, of 
the feature of summer fogs. As regards temperature, the extreme 
range is still very nearly the same at Los Angeles as at San Francisco; 
but the averages are very considerably higher at the former point, that 
of the winter being 60°, that of summer about 75° Fahrenheit. At 
intermediate points along the coast, local variations excepted, the aver- 
ages vary as sensibly as the latitude. As to rainfall along the coast, 
its decrease is slow, descending from 24 inches at San Francisco to 15 
at Santa Barbara, 12 at Los Angeles, and 9 to 10 at San Diego. But 
in the interior valley the decrease is much more rapid, as previously 
stated, moditied locally, according as the divide of the Coast Range is 
so high as to preclude the access of moisture from the sea, or jow enough 
to admit its inflnence. The same factor influences also the cooling and 
moistening efiect of the summer winds and fogs, which temper the 
summer climate of the Los Angeles Plain, but fail to reach the Mojave 
Desert or the fervid plains of the upper San Joaquin Valley. 
SOILS OF CALIFORNIA. 
In a region of such vast extent, traversed by mountain ranges formed 
of rocks of ali kinds and ages, there is of course an endless variety of 
soils, to describe all of which would be beyond the limits cf the present 
article, even if the data were available. Unfortunately this is far from 
being the case, the geological survey having paid but little attention to 
the examination of soils, which, it is true, is a subject requiring special 
