432 RESOURCES OF CALIFORNIA. 



necessary for a comfortable sleep. The climate is just of that 

 character most favorable to the constant mental and physical 

 activity of men, and to the unvarying health and continuous 

 growth of animals and plants. In the interior, the summers 

 are much warmer than near the ocean ; while in the mountains 

 the winters are much colder. By travelling a few hundred 

 miles, the Californian can find almost any temperature that 

 he may desire — great warmth in winter, and icy coldness in 

 summer. 



The rocks of the state are chiefly granite and tertiary sand- 

 stone; the former occupying the high mountains, the latter 

 the valleys. In former eras there were several, or perhaps 

 many volcanoes in the range of the Sierra Nevada. Mount 

 Shasta was one of them, and it now has hot springs on its 

 summit, and sends up sulphurous vapors. On the w^estern 

 slope of the Sierra Nevada, about half way between the sum- 

 mit and the foot, are numerous beds of slate and veins of 

 quartz. The same formations are found in the Klamath basin 

 and in other parts of the state ; and in nearly every case they 

 are auriferous. There is scarcely a county which does not 

 contain gold. The districts which contain enough gold to sup- 

 port a mining population, have an area of about ten thousand 

 square miles. The gold-yield of the state is about forty-three 

 million dollars annually — more than that of any other country, 

 save the colony of Victoria, in Australia. 



The number of men engaged in mining may be estimated at 

 eighty thousand. Oar placers and auriferous quartz veins are 

 almost inexhaustible ; there are great mountains of gold-bear- 

 ing gravel which cannot be washed away for a century to 

 come ; and the quartz-lodes will last still longer. 



The gold-mining of California is conducted in the most 

 thorough and enterprising manner. Although the main prin- 

 ciples of the sluice and the hydraulic washing were known and 

 used, on a small scale, long before the discovery of gold in 

 California, it was here that those modes of working were first 

 perfected, applied on an extensive scale, and brought into uni- 



