He took his station sideways on a log of about twenty inches diameter, and began to roll it beneath him by walking rapidly forward. As the timber gained its momentum, the boy increased his pace, until finally his feet were fairly twinkling beneath him, and the side of the log rising from the river was a blur of white water. Then suddenly with two quick strong stamps of his caulked feet the young riverman brought the whirling timber to a standstill. "That's birling a log," said he to Bobby. They walked out on the main boom still farther. The smaller partitions between the various enclosures were often nothing but single round poles chained together at their ends. On these Bobby was not allowed to venture. "How deep is it here?" he asked again. "Bout thirty feet," replied Jimmy Powers. Bobby for an instant felt a little dizzy, as though he were on a high building. All this fabric on which he moved suddenly seemed to him unreal, like a vast cobweb in suspension through a void. It was a brief sensation, and little defined in his childish mind, so it soon passed, but it constituted while it lasted a definite subjective experience which Bobby would always remember. As he looked back, the buildings of the river camp, lying low among the trees, had receded to a great distance; apparently at another horizon was the dark row of piling that marked the outer confines of the booms; up and down stream, as far as he could see, were the logs. Bobby suddenly felt very much alone, with the blue sky above him, and the deep black water beneath, and about him nothing but the quiet sullen monsters herded from the wilderness. He gripped very tightly Jimmy Powers's hand as they walked along. But shortly they turned to the left; and after a brief walk, mounted the rickety steps to the floor of the hut where dwelt old man North, and the winch for operating the swinging boom. Old man North was short, dark, heavy and bearded; he smoked perpetually a small black clay pipe which he always held upside down in his mouth. His conversation was not extensive; but his black eyes twinkled at Bobby, so the little boy was not afraid of him. When he saw the two approaching, he reached over in the corner and handed out a hickory pole peeled to a beautiful white. "The wums is yonder," said he. Bobby put a fat worm on his hook and sat down in the opposite doorway were he could dangle his feet directly over the river. Where the shadow of the cabin fell, he could see far down in the water, which there became a transparent fair green. Close to the piles, on the tops of which the hut was built, were various fish. Jimmy leaned over. "Mostly suckers," he advised. "Yan's a perch, try him."