“Certainly, sir,” the driver responded. “You see this is the way of it. That court house there used to be the female prison in the old times, and for years it was crowded with women that the government had sent out here to punish ’em. They were lifers, most of ’em, and I suppose they are pretty near all dead now. If any of ’em is alive, they’re pretty old. Them that was kept in prison had to do hard work, making clothes and that sort of thing, but a good many of ’em went out as assigned servants to do housework, and they had to work in the fields, too; but those days is gone now, and all the prisons we have in Brisbrane in these times is for them that commits crimes right here on the spot.”

“Do you mind that round building up there with the mast on it,” said the cab driver, pointing to a structure that looked like a windmill with the arms of the mill removed.

“Yes, I see it,” said Harry; “what about it?”

“We call it the Observatory,” was the reply, “and that’s what it is. That mast there is for signaling ships when they come into the harbor. In the old times there was a windmill there, where they used to grind grain into flour and meal for the convicts to eat, and I guess 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 the time for turning machinery and grinding grain, or doing some other work. Most of the treadmills I ever knew anything about in the old country were just treadmills, and that was all.”