often got ten times that much in one pan!"

"Exactly. Yet you're not a millionaire, are you? Most gold-mines run
on a narrow margin of profit, a dollar or two to the ton of ore
crushed. So, you see, the works must be on a huge scale in order to
return a dividend on the investment. What's more, you can't afford to
establish a big plant unless there's an enormous amount of ore
available.

"It's an old rule of wise investors not to put money into a mine that
looks too rich. Why?

"Because rich ore generally peters out fast. The rich mines always
catch the suckers easily, and they're the ones who lose. A few cents a
ton profit on an immense deposit of low-grade ore means a sure return,
because, as a rule, such ore comes from a very old geological
formation where the gold is evenly scattered, and labor-saving
machinery can be put in with a certainty that those few cents of
profit will continue indefinitely.

"Gold, as you know, Jim, is always the same price. This has been
agreed upon by all nations. It is the one standard of value. It is
worth a fraction over $20 an ounce. Year in, year out, all over the
world, gold is worth the same.

"As a result, a gold-mine manager who knows the exact proportion of
gold per ton in the ore of his mine, can calculate to a cent how much
he can afford to pay for mining the ore, crushing it, and separating
the gold by chemical processes. He must figure on the cost of
installing his machinery, on his interest for original outlay, on
depreciation, on the cost of power for his machinery, on the water
power needed for crushing and washing, on transportation for his
supplies and on wages. Usually he will have to build his own railroad
and his own aqueducts. A little saving in one place--even a few cents
per ton--will enable him to make a big profit; a little extra cost,
such as an increase in the price of fuel, of chemicals, or of wages,
will make him bankrupt.

[Illustration: WHERE DESERTS YIELD MILLIONS.

Mill of the Pittsburg-Silver Peak Gold Mining Co., Blair, Nevada.]

[Illustration: THE EATER OF MOUNTAINS.

A hydraulic jet of high pressure, washing away a hill of gravel and
sending the pay dirt through a sluice.

_From "The Romance of Modern Mining," by A. Williams._]

"That is why, Jim, even the richest-ored mine in the world--if it be
uneven in its yield of gold per ton--may be worthless, and why a
low-grade mine with an unchanging percentage may be worth millions, so