376 TRANSACTIONS OF THE 



This region is possessed of wonderful fertility, and is capable of supporting 

 a denser population than any other part of California. The conditions of 

 soil and climate are such, that it will produce almost any crop that can be 

 grown between the latitudes of Lake Manitoba and Key West. 



It is this region which we shall chiefly consider in speaking of Southern 

 California. Its hoard of grain already contributes to feed the overcrowded 

 population of London: its preserved fruits are sold in the cities of Southern 

 Italy. 



SOIL. 



There are many varieties of soil to be found in the southern counties of 

 California. These in their bearing upon the climate of the region may be 

 classified with respect to their retentiveness of moisture. The non-reten- 

 tive soil includes the red and blue clays, of which there are but little, and 

 the well known adobe. The latter is more or less abundant, occurring in 

 irregular patches from a few acres to several square miles in extent. 



The retentive soils comprise the gravelly loams, the micaceous sediments, 

 and the so called sand bottoms along the river courses. This classification 

 may seem at first paradoxical, but facts are stronger than theory, for while 

 the wet and boggy clay and adobe bakes under a semi-tropical sun into a 

 friable and perfectly dry mass, the sands and more porous soils are moist 

 throughout the year. This peculiarity, which is due to capillarity, is not 

 only an important element in insuring great productivity to the soil, but it 

 also exerts a decided effect in moderating the severity of the Summer's 

 heat. The soil of the eastern part, or the arid region, and also the detritus 

 brought down by the rivers during the Winter floods, is commonly called 

 ''sand." Of true sand, however, there is not a particle, excepting along 

 the coast. The alleged "sand" is nothing more than disintegrated granite 

 rock, rich in feldspar, and containing a notable quantity of mineral phos- 

 phates. 



This is the secret of the wonderful productiveness of the soil wherever 

 watered; it is also a most important factor in determining the fine quality 

 of the fruit and vintage, for which Southern California has already a world- 

 wide reputation. 



HUMIDITY. 



Under this head we will consider the annual rainfall, and independently 

 the amount of moisture present in the atmosphere. A knowledge of the 

 total rainfall of a region gives but little insight as to its climatic conditions; 

 the distribution of the rainfall reveals much. In. Southern California, as 

 on the Pacific Coast generally, the rainfall occurs almost wholly during the 

 Winter months. A few scattering showers occur in November and Decem- 

 ber; heavier rains fall during the following three months, especially during 

 February and March. There are occasional rains in April, and rarely in 

 May. In the mountains, however, there are at times heavy mists, and 

 even dashes of rain. 



The average rainfall of the southern part of the State may be seen from 

 the following table. Of the five stations mentioned, Santa Barbara and 

 San Diego are on the coast; Los Angeles is about seventeen miles inland. 

 San Bernardino, about sixty miles inland. Yuma is situated in the heart 

 of the arid basin region, the town is just over the line in Arizona (old Fort 

 Yuma is in California). 



