personified the contests of the human race from
the beginning of the world, in the effort to conquer nature, and to make
it contribute to their necessities.

The Professor knew how such a condition would tend to make active minds
either productive of good, or to fly out in the opposite direction and
cultivate the low and sordid instincts. Occupation, work, the
utilization of the mind, and above all, to direct their energies into
useful channels, had been the Professor's one absorbing aim.

The boys had responded, as all boys will, not for the love of gain or
for power or glory. Our boys had none of these. Other boys do not need
them any more than those on Wonder Island. What they do need is a true
stimulus for work; and when that evening they were gathered together in
the cozy little living room at the Cataract, the Professor who for two
days had been particularly reticent and retired, said:

"Can you imagine the condition of the pirates who gathered all that
hoard in the cave? What do you think their aim was in life?"

"It seems to me," was Harry's reply, "that the only thing they were
after was wealth."

"If what we see in the cave is any indication, the principal thing they
lived for was to kill somebody," was George's conclusion.

The answers made him smile. "You have, I presume, answered the question
in the two sentences. But there is something that you haven't mentioned,
which is at the bottom of it all."

"Yes; wanting to kill to get the money."

"That only states your previous answers in a more concrete way. There is
one word which describes it accurately: Selfishness. When a man inquires
into the secrets of nature; when he tries to turn the knowledge gained
into account, either for money or glory; when he consistently devotes
his days to labor, and his nights to thoughts to find out how he may do
something better, or quicker, or cheaper, it might all be denominated
selfishness, and so it is, in a way. It is a selfishness, however, that
does no injury to a fellow-man. That kind of selfishness is the great
quality which has produced the wonderful things that we see all about
us, and which distinguishes the man from the brute creation."

"But I have read of a great many men who made millions and millions and
who never did any of the things you have just referred to," answered
Harry.

"Then do you think they are any better than the pirates were?"

Notwithstanding the exciting times, food was a necessit