rapidly that in 1852, the fifth year after the discovery, it reached the maximum production of $81,294,700. More than half of the total production for the sixty-eight years was made in the first twenty years after the discovery of gold. The production rapidly decreased after reaching its maximum in 1852, until it had fallen in 1889 to $11,219,913. Meanwhile the exhaustion of the easily accessible placer deposits had directed the attention of miners to the values carried in veins and in low-grade placer deposits which could only be worked by the expensive mechanical process known as dredging. Both vein mining and placer dredging require the investment of large sums of money and the use of a much higher degree of skill. By these methods, the gold production of the state has been gradually increased until in 1915 it reached the value of $22,442,296, but it has never approached the maximum realized in the fifth year after the discovery of gold.
When it is recalled that the population of Mexico was much more dense than that of California when gold was discovered and that for three hundred years the people had been engaged in gold and silver mining, and the development of that industry had been stimulated by the urgent demands of the mother country for the payment of tribute in these precious metals, it will be seen that the probability of the exhaustion of the easily access-
