"I counted on Boomerang helpin' me," he said to Tom. "All he has to do is walk on dat tread mill, an' keep goin'. Dat makes de saw go 'round, an' I saws de wood. But de trouble am dat I can't git Boomerang to move. I done tried ebery means I knows on, an' he won't go. I talked kind to him, an' I talked harsh. I done beat him wif a club, an' I rub his ears soft laik, an' he allers did laik dat, but he won't go. I fed him on carrots an' I gib him sugar, an' I eben starve him, but he won't go. Heah I been tryin' fo' three days now t' git him started, an' not a stick hab I sawed. De man what I'm wukin' wif on shares he git mad, an' he say ef I doan't saw wood pretty soon he gwine t' git annuder mill heah. Now I axes yo' fair, Mistah Swift, ain't I got lots ob trouble?" "You certainly seem to have," agreed Tom "But why is Boomerang so obstinate? Usually on a treadmill a horse or a mule has to work whether they like it or not. If they don't keep moving the platform slides out from under them, and they come up against the back bar." "Dat's what done happened to Boomerang," declared Eradicate. "He done back up against de bar, an' dere he stay." Tom went over and looked at the mill. The outfit was an old one, and had seen much service, but the trained eye of the young inventor saw that it could still be used effectively. Boomerang watched Tom, as though aware that something unusual was about to happen. "Heah I done gone an' 'vested mah money in dis yeah mill," complained Eradicate, "an' I ain't sawed up a single stick. Ef I wasn't so kind-hearted I'd chastise dat mule wuss dan I has, dat's what I would." Tom said nothing. He was stooping down, looking at the gearing that connected the tread mill with the shaft which revolved the saw. Suddenly he uttered an exclamation, "Rad, have you been monkeying with this machinery?" he asked. "Me? Good land, Mistah Swift, no, sah! I wouldn't tech it. It's jest as I got it from de man I bought it off. It worked when he had it, but he used a hoss. It's all due to de contrariness ob Boomerang, an' if I--" "No, it isn't the mule's fault at all!" exclaimed Tom. "The mill is out of gear, and tread is locked; that's all. The man you bought it off probably did it so you could haul it along the road. I'll have it fixed for you in a few minutes. Wait until I get some tools." From the bag on his motor-cycle Tom got his implements. He first unlocked the treadmill, so that the inclined platform, on which the animal slowly walked, could revolve. No sooner had he done this than Boomerang, feeling the slats under his hoofs moving away, started forward. With a rattle the treadmill slid around.