140 HISTOKY OF CALIFORNIA. 



restored, the wind ceases ; a perfect calm prevails 

 until about the same hour the following day, when 

 the same process commences and progresses as be- 

 fore ; and these phenomena are of daily occurrence, 

 with few exceptions, throughout the dry season. 



" These cold winds and fogs render the climate at 

 San Francisco, and all along the coast of California, 

 except the extreme southern portion of it, probably 

 more uncomfortable, to those not accustomed to it, in 

 summer than in winter. 



"A few miles inland, where the heat of the sun 

 modifies and softens the wind from the ocean, the 

 climate is moderate and delightful. The heat, in the 

 middle of the day, is not so great as to retard labor 

 or render exercise in the open air uncomfortable. 

 The nights are cool and pleasant. This description 

 of climate prevails in all the valleys along the coast 

 range, and extends throughout the country, north and 

 south, as far eastward as the valley of the Sacramento 

 and San Joaquin. In this vast plain, the sea-breeze 

 loses its influence, and the degree of heat in the 

 middle of the day, during the summer months, is 

 much greater than is known on the Atlantic coast in 

 the same latitudes. It is dry, however, and probably 

 not more oppressive. On the foot-hills of the Sierra 

 Nevada, and especially in the deep ravines of the 

 streams, the thermometer frequently ranges from 

 110° to 115° in the shade, during three or four hours 

 of the day, say from eleven until three o'clock. In 

 the evening, as the sun declines, the radiation of heat 

 ceases. The cool, dry atmosphere from the mountains 

 spreads over the whole country, and renders the 

 nights cool and invigorating. 



"I have been kindly furnished, by Surgeon-General 



