Quotation from: The Cruise of the Snark

Written by: Jack London

"Of course," he added, "these are only theories of mine. I like to
speculate upon the glorious future of man. Levitation may not be
possible, but I like to think of it as possible."

One evening, when he yawned, I asked him how much sleep he allowed
himself.

"Seven hours," was the answer. "But in ten years I'll be sleeping
only six hours, and in twenty years only five hours. You see, I
shall cut off an hour's sleep every ten years."