Page:Popular Science Monthly Volume 72.djvu/77

Rh, the business of gold mining is on a stable and permanent foundation, it will be interesting to take account of the current annual crop of gold of the world. That the reader may acquire a mental grasp of its physical proportions it will be well to start with the fact that for the year 1906 this crop weighed nearly 674 tons. A cubic foot of pure gold will weigh just 1,20-1 pounds, so that the product of the world's gold mines for that year could be all packed in a room ten feet square and nine feet high. This cube was worth in money $407,379,893, and it came from the following places:

Judging by the experience of the last thirty years, during which the industry has been forming and steadily acquiring those characteristics that indicate stability, it is probable that under normal conditions, and if the laws governing the discovery and exploitation of gold mines in the various countries and those affecting the selling price of the metal (coinage laws) do not materially alter, each year will show a gain of about 5 per cent, in the amount and value of the annual crop.

At the present time, according to calculations and estimates made in 1900 by the director of the United States Mint, the gold that has been taken from the mines of the world since the discovery of America has amounted in quantity to about 21,424 tons, and in value to more than $12,600,000,000.

Now, of this vast total, the astonishing fact is that nineteen per cent., or nearly one fifth of the whole, has been taken out in the last ten years; thirty per cent., or almost one third, in the last twenty years; forty-one per cent, in the last thirty years; fifty-four per cent., or over one half in the last forty years; and sixty-eight per cent., or more than two thirds, in the last half century.

Assuming that no increase at all occurs in the annual output, this amount will be doubled in thirty years, while, if an annual increase of five per cent, is attained, the doubling will be accomplished in less than twenty.