276 
TlMEHRI. 
one dreams of washing drift which contains less than 
7 dwts. to the ton. From the hydraulic workings of 
California we obtain the following. " In Nevada County, 
16,000,000 cubic yards of drift gave gold equal to 30 cents 
per cubic yard. In Placer County 43,000,000 cubic yards 
gave 6 cents, and in Yuba County 25,000,000 cubic yards, 
gave 25 cents per cubic yard. The average yield of the 
Smartsville gravel is stated by WHITNEY at about 23 
cents per cubic yard." Now the miner's pan contains 400 
cubic inches, and as the wooden batea in use here is 
about the same size, its capacity may be taken at about 
the T £o part of a cubic yard, and as in our poorest work- 
ings, one batea of wash-dirt seldom produces less than 
2 grains weight of gold, and frequently up to 2 dwts. or 
more, a simple calculation will show that the value of 
our gold drift varies from $8, up to $200 per cubic yard, 
a degree of richness which makes the estimate of the 
Commissioner of Mines appear a singularly moderate 
one, and which taken in connection with the fa6l that in 
Australia each spademan is supposed to excavate six 
cubic yards of gravel per day, points, in the strongest 
manner possible, the Commissioner's strictures on the 
rude and inefficient manner of working generally exhi- 
bited in the colony. However marvellous may be the 
advances made in the natural sciences, and industrial arts 
in modern times, the art of gold-mining must be held to 
be an exception, as, if Pliny is to be believed, works 
were carried out in his day in Spain on a scale so stu- 
pendous that the gigantic operations of the hydraulic 
miners of California appear to be but a feeble reflex of 
them. How far behind the times British Guiana is, may 
be learned from the report of the Commissioner of Mines, 
