"I think I saw a head look out from that corner," Tom exclaimed suddenly, two hours after Sam had left them.

"I am quite sure I did, Tom. We must wait until he shows himself a bit more. I reckon it is a good three hundred yards off, and a man's head is a precious small mark at that distance. Stand a bit higher and lay your rifle on the wall. Don't fire if he only puts his head out. They know we can shoot, so there is not any occasion to give them another lesson. I don't hold to killing, unless you have got to do it. Let him have a good look at us.

"When he goes back and tells the tribe that there is a three hundred yards' straight passage without shelter, and a strong wall across the end of it, and two white men with rifles ready to shoot, I reckon they will know a good deal better than to try to come up it, as long as there is light. Besides, they won't think there is any occasion to hurry, for they won't count on our taking to the river, and will know that we shall be keeping watch at night. So it may very well be that they will reckon on wearing us out, and that we may not hear of them for a week. There is the fellow's head again!"

The head remained visible round the corner of the rock for two or three minutes.

"He knows all about it now, Tom. You won't see any more of him to-day. I will go down and lend them a hand below."

Tom asked no questions about the horses; he had thought of them a score of times as he stood on guard, and the thought had occurred to him that it was possible the shots he had heard while they were building the wall on the previous afternoon, had been the death shots of the horses. It did not occur to him when Sam was telling the story about the bear, that this was a got-up tale, but when he came to think it over, he thought it probable that it was so. Sam himself was not much of a shot, but Ben, although inferior to Harry or either of the two Indians, shot as well as Jerry, and would hardly have missed a bear three or four times running. Each time the thought of the horses occurred to him he resolutely put it aside, and concentrated his mind upon the probable perils of the passage down the cañons and the wonderful gorges they would traverse, and the adventures and excitement they were sure to pass through. He thought how fortunate it was they had taken the precaution of sending their specimens of quartz back to the fort; for were they in the canoes, the fruits of the journey would be irrevocably lost were these to upset; for now the Indians had twice discovered the presence of whites in the valley they would be sure to watch it closely, and it would not be possible to go up to the mine again unless in strong force.

The day passed quietly. Harry brought up Tom's meals, and late in the afternoon all hands came up, and the wall of stones was raised four feet, making it almost impregnable against a sudden attack. The two Indians took post there with Tom, and watched alternately all night. The Utes, however, remained perfectly quiet. They probably felt sure that the fugitives must sooner or later be forced to surrender, and were disinclined to face the loss that must occur before so strong a position, defended by seven men armed with rifles and revolvers, could be carried.

At three o'clock on the following afternoon Hunting Dog came up. "Tom go down and get dinner," he said, "Hunting Dog will watch."

Tom took his rifle and started down the cañon.

"Come on, lad," his uncle shouted. "We are pretty near ready for a start, and have all had our dinner; so be quick about it. We want to get well away from here before night."