You mean to say he takes those big, jug-like things down there empty and brings them up full?î Johnny Thompson, the boy from Illinois who had travelled far and seen many strange things, stared at Ballard Ball, the red-headed boy of the Cumberland Mountains of Kentucky, with surprise. If the truth were told, he found himself doubting the other boyÍs story. Here he was standing in the grinding room of an old fashioned mill watching massive stone wheels grind the corn he had carted from his cousinÍs store and at the same time discovering what promised to be a first class mystery right down here in the slow old Cumberland mountains where, he had supposed, nothing unusual ever happened. ñBut whatÍs down there?î He was looking at the floor of the mill. At the same time he was hearing a curious sound, a sucking and hissing that might, he thought, have been the working of a small steam engine. But of course there was no steam engine, for there was no smoke stack and no smoke. ñNothing down there but water. Some machines he brought months ago. TheyÍre down there. The water wheel runs them,î the other boy drawled. ñOf course he wouldnÍt bring water up in the jugs and cart them away. Why should he? ThereÍs water everywhere. This river runs for miles. Besides,î his voice dropped, ñthat stuff he brings up is queer. ItÍs cold and it smokes. Yes sir, a sort of white smoke comes off it all the time.