For seven miles along William's Creek worked four thousand men. Cariboo Cameron took a hundred and fifty thousand out of his claim in three months. In six months of '63 William's Creek yielded a million and a half dollars, and this was only one of many rich creeks. From '59 to '71 came twenty-five million dollars in gold from the Cariboo country. By '65 hydraulic machinery was coming in and the prospectors were flocking out; but to this day the Cariboo mines have remained a freakish gamble. Mines for which capitalists have paid hundreds of thousands have suddenly ended in barren rock. Diggings from which nuggets worth five hundred dollars have been taken have petered out after a few hundred feet. Even where the gravel merged to whitish gold quartz, the most expert engineer in the camp could not tell when the vein would fault and cease as entirely as if cut off. And the explanation of this is entirely theoretical. The theory is that the place of the gold was the gravel bed of an old stream, an old stream antedating the petrified forests of the South-west, and that, when vast alluvial deposits were carried over a great part of the {49} continent by inland lakes and seas, the gold settled to the bottom and was buried beneath the deposits of countless centuries. Then convulsive changes shook the earth's surface. Mountains heaved up where had been sea bottom and swamp and watery plain. In the upheaval these subterranean creek beds were hoisted and thrown towards the surface. Floods from the eternal snows then grooved out watercourses down the scarred mountainsides. Frost and rain split away loose debris. And man found gold in these prehistoric, perhaps preglacial, creek beds. However this may be, there was no possible scientific way of knowing how the gold-bearing area would run. A fortune might come out of one claim of a hundred feet and its next-door neighbour might not yield an atom of gold. Only the genii of the hidden earth held the secret; and modern science derides the invisible pixies of superstition, just as these invisible spirits of the earth seem to laugh at man's best efforts to ferret out their secrets.