242 KESOUllCES OF CALIFORNIA. 



are those in gullies which have no water, save during a small 

 part of the year. A " claim" is the mining land owned or 

 held by one man or a company. 



The placer mines are again classified according to the man- 

 ner in which, or the instruments with which they are wrought. 

 There are sluice claims, hydraulic claims, tunnel claims, dry 

 w^ashing, dry digging, and knife claims. In 1849 and 1850, 

 the main classification of the placers was into wet diggings 

 and dry diggings, the former meaning mines in the bars and 

 beds of rivers, and dry diggings were those in gullies and flats 

 where water could be obtained only part of the year or not at 

 all. That classification was made while nearly all the mining 

 was done near the surface, before the great deposits of pay- 

 dirt in the hills had been discovered, and before ditches, sluices, 

 and the hydraulic process had been introduced. The class of 

 mines then known as the " dry diggings," and which for 

 several years furnished nearly half of the gold yield of the 

 state, are now, with a few unimportant exceptions, exhausted, 

 or left to the attention of the Chinamen. 



The purpose of all placer miners is not to catch all the gold 

 in the dirt which they wash, but to catch the greatest possible 

 quantity within a given time. It is not supposed that any 

 process used in gold mining catches all the metal. Part of it is 

 lost ; in some processes a considerable j)roportion. The general 

 estimate in California is, that one-twentieth of the gold in the 

 dirt which is washed is lost. Many of the particles are so 

 very small as to be invisible to the naked eye, and so light 

 that their specific gravity does not avail to prevent them from 

 being carried away by the water like sand. The larger pieces 

 will sink to the bottom and resist the force of the water ; the 

 smaller the particles, the greater the danger that it will be 

 borne away. Many devices have been tried to catch all the 

 gold, but none have succeeded perfectly, and some which have 

 caught a portion of what escaped from the ordinary modes of 

 mining, have been found to cost more than their yield. The 

 miner does not grieve about that which he cannot catch. Ho 



