On nearer approach it was seen that the herd was "milling," that is, revolving in a great circle, with a number of inner circles, half smothered in the dust they raised, without aim or knowledge of what they did, or why. About the herd at various points stood the half-dozen shepherds, their long crooks in their hands. Whenever a blatting animal made a dash for liberty the dogs drove it into the press, barking and nipping. Larkin rode to a tall, dark-skinned shepherd, a Basque from the California herding. "What is it, Pedro?" he asked. "What is the matter with them?" "Only the good God can tell. The leaders they take fright at something, I do not know, and we 'mill' them before any damage is done." Larkin rode around the trampling, bawling mass to the rear, where were the cook wagon and a couple of spare horses. He at once dismounted and changed his uncomfortable riding-boots for the brogans of the herder. Pinte he relegated to the string, for the use of a horse with sheep is ludicrous, since the dogs are the real herders, and obey the orders given by the uplifted arms of the men. When he rejoined Sims, the sheep had become calmer. The flock-mind, localized in the leaders, had come to the conclusion that, after all, there was nothing to fear, and the circling motion was gradually becoming slower and slower. In a quarter of an hour comparative quiet had been restored, and Sims gave the order to get the flock under way. Since they had not come upon water at this place, as the herder had hoped, it was necessary to continue the merciless drive until they found it. Immediately the dogs cut into the dirty-white revolving mass (the smell of which is like no other in the world), and headed the leaders north. But the leaders and tail-enders were inextricably mixed, and for a long time there was great confusion. Sheep on the march have one invariable position, either among the leaders, middlers or tailers, and until each animal has found his exact post, nothing whatever can be done with him. Until night fell the animals fed on the dry bunch-grass, and then, under the trotting of the dogs, took position on the brow of a rising hill, as though bedding down for the night. But all did not rest, for perhaps fifty remained standing in the perpetual flock-watch. In an hour these would lie down and others take their places, but all through the night, and at any time when the flock rested, this hereditary protection would become operative--seemingly a survival of a day when neither man nor dog had assumed this duty. The cook dug his trench, built his fire and set his folding table out under the pale sky that was just commencing to show brilliant stars. After the last cup of steaming coffee had been downed and pipes lighted, Sims gave the order to march. The herd was nearly still now, and roused with much complaining, but the dogs were inexorable, and presently the two thousand were shuffling on, feeding now and then, but making good progress.