State Agricultural Society. 131 



mometer lias fallen at this place was also twenty-seven degrees, on 

 the same day in December, ei.nliteen hundred and seventy-six. There 

 is a remarkable uniformity in the clinuitc throu^diout the Sacramento 

 Valley. In it a difi'erence of five degrees of latitude, between thirty- 

 live degrees and thirty minutes and forty degrees and thirty minutes 

 only lowers the annual average temi)erature four degrees and fifteen 

 minutes. The difference of the annual average temperature between 

 corresponding degrees of latitude in the Atlantic States at an equal 

 distance from the ocean is more than eight degrees. It has been 

 found that the foot-hills of the Sierra, up to a height of about two 

 thousand five hundred feet, have apparently the same temperature 

 as places in the valley having the same latitude. It has also been 

 found that with increased elevation there is an increase of rainfall 

 over those i)laces in the valley having the same latitude as, for illus- 

 tration, Sacramento with an elevation above the sea of thirty feet 

 has an annual mean temperature of sixty degrees and forty-eight 

 minutes, and an average fall of rain of eighteen and twenty-hve 

 one-hundredths inches, while Colfax, wath an elevation of two thou- 

 sand four hundred and twenty-one feet, has an annual mean tem- 

 perature of sixty degrees and live minutes, and an average annual 

 rainfall of forty-two and seventy-two one-hundredths inches. This 

 uniformity of temperature and increase of rainfall appears to be 

 the law througliout the whole extent of the foot-hills of the Sierra, 

 with this variation as relates to temperature, namely, as latitude is 

 decreased the temperature of the valley is continued to a proportion- 

 ally greater elevation. To illustrate, approximately, if the tempera- 

 ture of Reading at the northern end of the valley is continued up 

 the foot-hills to a height of two thousand feet, then the temperature 

 of Sacramento in the center of the valley would be continued up to 

 two thousand five hundred feet, and that of Sumner in the extreme 

 southern end of the valley uj) to three thousand feet. The increase 

 of rainfall on the foot-hills in the latitude of Sacramento, due to 

 elevation, is about one inch to each one hundred feet. South from 

 Sacramento the proi)ortion decreases until at Sumner the increase 

 due to elevation is but half an inch to each one hundred feet. This 

 is shown by the record kept at Fort Tejon in the Tehachipa Mount- 

 ains, near Sumner, at an elevation of three thousand two hundred 

 and forty feet, M'here the annual rainfall is nineteen and fifty-three 

 one-hundredths inches. There is no record kept at any point in the 

 hills above Reading, but probably in this latitude the increase due 

 to elevation is about one and a half inches to each one hundred feet. 

 The increase of i)recii)itation on the hills at the northern end of the 

 valley gives greater density to the forests, and permits them to grow 

 at lower elevations than in the southern end of the valley. At the 

 same time the ditference in temperature is so small that the character 

 of the vegetation of the hills at each end of the valley is not dis- 

 similar. The trees that are found in the vicinity of Reading, at the 

 northern end of the valley, below an elevation of five hundred feet, 

 are not found at the southern end until we pass Caliente at an eleva- 

 tion of one thousand three hundred feet. It would seem that the 

 temperature of the valley ])revails up the Sierra to an elevation that 

 equals the average height of the Coast Range of mountains. If a 

 line were drawn parallel to the surface of the ocean from the top of 

 the Coast Range east until it met the flanks of the Sierra, it would 

 mark a level on the Sierra below which the temperature would not 



