s other
folks ate it, too. When the wind blew the arm went round and round, the
machinery worked, and the stones revolved and ground out the meal.
Sometimes they didn't have no wind, because it didn't blow, but they had
a treadmill there, and then they used to bring up a string of convicts,
and put them on the treadmill to run the machinery and keep up the
grinding of the grain. I suppose you know what a treadmill is?"

"I have heard about a treadmill," said Harry, "but I never saw one." Ned
nodded, and said that he was in the same predicament.

"Well," said the driver, "I have seen one in the old country; I never
saw the one here, because it was gone before I came to Brisbane. What I
saw was a wheel in the shape of a long cylinder with twenty-four steps
around the circumference of it; in fact, it didn't look much unlike the
paddle-wheel of a steamboat, where the men stood to turn it. Each one of
'em was boarded off from his neighbor so that they couldn't talk to each
other. There was a hand rail for them to hang on to. The weight of the
prisoners' bodies on the steps caused the wheel to turn, and they sent
it around about twice a minute. A man on a treadmill has got to work, he
can't get out of it. If he tries to avoid stepping, he's got to hang his
weight on the hand rail with his arms, and after he has tried that for a
minute or so he's glad to go back to stepping again."

"I should think," said Ned, "that it would be difficult to adapt it to
the weight of different individuals, and also to their height. While it
might not be too much for a strong man, it might be for a weak one; and
if the position of steps and rail were adapted to a tall man, they
wouldn't be for a short one."

"I believe that's just the trouble they found with it in the old
country," was the reply; "and it's mostly been given up there. They've
got a machine in the place of it which they call 'the Crank,' which can
be adapted to anybody. It's a wheel with paddles to it, and turns inside
a box. They put gravel in the box, graduated to the strength of the man
who is to turn it, and the prisoner's hard labor consists in turning the
crank."

"It doesn't serve any useful purpose, as the treadmill does, I presume?"
said Harry.

"No; there is no useful purpose about it. A man has to turn that crank
because he's been sentenced to hard labor, and there's nothing else they
can put him to, that's all. And they don't by any means use the
treadmill all t