There are two smelters in Denver and one each in Golden, Leadville, Canon City, Pueblo and Salida. None but zinc ores are sent out of this State. The annual output of gold in Colorado is about twenty-two million dollars, or about six million dollars a year greater than California. There are three operated Mints in the United States: Denver, Philadelphia and San Francisco. At Denver there are six hundred million dollars of gold deposited in the vaults beneath the foundations of the Mint, and upon this reserve the paper currency of the Government has been issued. No such amount of gold is stored in any other building in the world. The Denver Mint will always remain the storage depository for the gold reserve of the nation, because of its inland location, where it is remote from attack by sea. Colorado has already produced in gold four hundred and eighty-eight million five hundred thousand dollars, and there is no indication of a diminution in the supply. Of the seven billions of the world's gold, nearly one-fourth, or approximately one billion six hundred million is held by the United States. When Columbus first started on his voyage of discovery there was less than two hundred million dollars of gold in the world; now, more than double that amount is produced in a single year. In 1500 the annual gold production was four million dollars, and it took two hundred years before the yearly output was doubled. Now, nearly five hundred million dollars in gold is taken out of the earth each year. Only in the past few years has the production of gold assumed such gigantic proportions as to be alarming. In 1800 it was but twelve million dollars annually. In 1900 it was two hundred and sixty-two million dollars yearly, and in the past ten years it reached the enormous output of more than four hundred and fifty-seven million dollars every year. The Transvaal country alone turns out over one hundred and fifty million yearly. This great increase is due to improved methods of mining. Machinery unknown ten years ago, has done away with the primitive methods that kept the production of gold constant and within bounds. In the Transvaal, the hills and valleys are being ground up by powerful machines that separate the gold from the earth and rock. Then, too, a giant stream of water is now turned against the base of a mountain that melts away like mist before the sun, and sends a stream of gold to the mint.