Still higher Adam pulled himself so that he might see under the brush shelter. A wide rent in the roof--a huge brown flash across this space--then lower down a movement of men to and fro--rumble of rocks, clink of shovel, thud of earth, creak and crack--a red undershirt--blue jeans--boots, and then passing, bending men nude to the waist--circle and sweep of long dark streak--then again the huge brown flash; it all bewildered Adam, so that one of his usually distinguishing glances failed to convey clear meaning of this scene. Then he looked and looked, and when he had looked a long, breathless moment he fell flat on the soft clay, digging his big hands deep, trembling and straining with the might of his passion to rush like a mad bull down upon the ruffians. It took another moment, that battling restraint. Then he raised to look with clearer, more calculating gaze. The brush roof was a shelter for an _arrastra_. The octagonal shape of this sun shade filled the pocket that nestled between the slopes. Its back stood close to the ledge of crumbling rock from which the gold-bearing ore was being extracted. Its front faced the open gully. Under it an _arrastra_ was in operation. As many of these Spanish devices as Adam had seen, no one of them had ever resembled this. In the center of the octagon a round pit had been dug into the ground, and lined and floored with flat stones. An upright beam was set in the middle of this, and was fastened above to the roof. Crossbeams were attached to the upright, and from these crossbeams dragged huge rocks held by chains. A long pole, like the tongue of a wagon, extended from the upright and reached far out, at a height of about four feet from the ground. The principle of operation was to revolve the crossbeams and upright post, dragging the heavy rocks around and around the pit, thus crushing the ore. Adam knew that mercury was then used to absorb the gold from the crevices. The motive power sometimes was a horse, and usually it was a mule. But in this instance the motive power was furnished by a man. A huge, broad, squat man naked to the waist! He was bound to the end of the long bar or tongue, and as he pushed it round and round his body was bent almost double. What wonderful brawny arms on which the muscles rippled and strung like ropes! The breast of this giant was covered with grizzled hair. Like a tired ox he bowed his huge head, wagging it from side to side. As he heaved around he exposed his broad back--the huge brown flash that had mystified Adam--and this mighty muscled back showed streaks and spots of blood. A gaunt man, rawboned and dark, with a face like a ghoul, stood just outside the circle described by the long bar. He held a mesquite branch with forked and thorny end, which he used as a goad. Whenever the hairy, half-naked giant passed around this gaunt man would swing the whip. It cracked on the brown back--spattered the drops of blood.