12 



It is only at evening that the change is perceptible, for as the temperature de 

 creases after nightfall, a heavy mist from the condensation of the moisture held 

 in solution by high temperature takes place, which is often equivalent to a light 

 rain. 



On the middle portions of the Salinas, much the same features are observed, 

 and it is no uncommon circumstance to be in a cloud of mist at one point, and 

 at another on the same plain not three miles the atmosphere as clear as nature 

 can produce it ; it is instructive as well as interesting to stand in a commanding 

 position and witness the solution of the cloud of vapour as it passes a given and 

 well defined line. 



The same features are prevalent on the valley sections lying east of the Mount 

 Diablo Range, and the effects of condensed moisture are very apparent even in 

 the western foothills of these districts. In this fact lies one of the secrets of 

 the productive capacities of the soils of many of these interior sections, and were 

 it not for this peculiarity of our atmosphere a large area of our inland country 

 would remain a perfect Sahara, suited neither for man or beast. 



On some parts of the valley sections there have been observations conducted 

 through a short period of the last year, for the purpose of eliciting some infor 

 mation relative to the hygrometric condition of the atmosphere many miles from 

 the sea. These observations if continued for one or two years hence, will furnish 

 us valuable and interesting information relative to the amount of atmospheric 

 moisture of the interior of the State, from which we shall be able to deduce some 

 conclusions of the productive capabilities of many parts of the valleys that are 

 now neglected, under the prevailing idea that water sufficient for the propaga 

 tion of grains does not exist in these sections ; from what information upon this 

 subject, is in a tangible form, I am led to the conclusion that the atmosphere of 

 the central portions of the Plains of San Joaquin and Sacramento, is nearly or 

 quite saturated during seven months of the year. The prevalence of southerly 

 winds on these plains is always marked by an increase in the height of the dew- 

 point, and they are found by tables, kept during the year 1854, to constitute 

 nearly sixty-nine per cent, of the winds of the summer season. 



Beyond the junction of the coast mountains, the San Bernardino Chain makes 

 its inception, and forms the coast-line for a considerable distance to the south. 

 It is at this point where one of the great errors relating to the physical geogra 

 phy of this part of the State has been committed, viz : that of blending the 

 western terminus of this chain with the coast-line of mountains proper. From 

 Point Aguilla the coast begins to assume a much more easterly direction, than 

 at any other point north of this locality (except perhaps in the immediate vicin 

 ity of Cape Mendocino,) and on passing Point Conception it pursues nearly a due 

 east trend until arriving at Point Dessolata to the south of the Mission San 

 Juan Capistrano, when it again assumes its easterly course after rounding that 

 point. 



At a short distance north of Point Aguilla the base of the San Bernardino chain 

 fronts the coast, at times miles distant, at others approaching the water-line ; 

 after passing the south-eastern point of the Santa Barbara channel the chain is 

 seen stretching away in the distance nearly due east towards the waters of the 

 Colorado, and across the Jornada del Muerto dividing this desert into two un 

 equal parts. 



On approaching San Pedro in the county of Los Angeles we find that the 

 nearest part of this chain is not less than forty miles distant from the coast, and 

 to the northeast of this place the distance is much greater. At the distance of 

 seventy miles in the same direction may be seen the high peaks of San Bernar 

 dino, and beyond it again, that of San Jacinto ; farther to the west are moun 

 tains near the Cahon Pass, while to the left of this line of view and at nearly 

 the same distance are the rugged peaks of the Sierra San Jose and San Gabriel. 



