CLIMATE. 97 



The following table furnishes the figures for a comparison 

 of temperature at various points on the Central Pacific Rail- 

 road across the State, from the level of the sea to the summit 

 of the Sierra : 



TOWNS. JANUARY. JULY. DIFFERENCE. ELEVATION, 



dcg. deg. (leg. feet. 



San Francisco 49 57 8 30 



Livermore 48 68 20 485 



Sacramento 46 72 24 30 



Auburn 45 75 30 1363 



Alta 43 75 32 3612 



Cisco 30 62 32 5939 



Summit 27 60 33 7017 



Truckee 23 53 30 5846 



It will be observed that the winter becomes cooler regular- 

 ly, as we ascend the Sierra, and also after we begin to de- 

 scend on the eastern side, the January of Truckee being seven 

 degrees colder than that of Cisco, at a higher elevation on the 

 western slope. The heat of midsummer increases till we reach 

 an elevation of 3,000 feet, and then begins to decline. 



January and July are the two typical months, and from 

 them we can form a good general idea of the temperature of 

 a place. 



We observe, in the above table, that the January of San 

 Francisco is 4 warmer than that of Sacramento, 7 warmer 

 than St. Helena, 18 warmer than New York, 12 warmer 

 than London, and 3 warmer than Naples. 



San Francisco's July, on the other hand, is 16 cooler than 

 that of Sacramento, 14 cooler than that of Santa Barbara, 

 20 cooler than St. Helena, 33 cooler than Millerton, 20 

 cooler than New York, and 19 cooler than Naples. 



The difference between the mean temperatures of January 

 and July, is 9 greater at Santa Barbara, 20 greater at Sacra- 

 mento, 27 greater at St. Helena, 35 greater at Millerton, 34 

 greater at New York, and 22 greater at Naples, than at San 

 Francisco. 

 7 



