"A hint to the wise is a stitch in time," said Obed White. "Those fellows are getting too noisy. I object to raucous voices making loud outcries, nor does the sound of bullets dropping near please me. I shall give them a hint." Wheeling about he fired at the nearest Mexican. His rifle was a long range weapon and the man fell with a cry. The others hesitated and the fugitives increased their speed. Now they were at the base of the mountain. Now they were up the slope which was densely clothed with trees and bushes. Then they came to a great hollow in the stone side of the ridge, an indentation eight or ten feet deep and as many across, while above them the stone arched over their heads at a height of seventy or eighty feet. "We'll just stay here," said Obed White. "You can run and you can run, but the time comes when you can run no more. They can't get at us from overhead, and they can't get at us from the sides. As for the front, I think that you and I, Ned, can hold it against as many Mexicans as may come." "At least we'll make a mighty big try," said Ned, whose courage rose high at the sight of their natural fort. They had their backs to the wall, but this wall was of solid stone, and it also curved around on either side of them. Moreover, he had a chance to regain his breath which was once more coming in hot and painful gasps from his chest. "Let's lie down, Ned," said Obed, "and pull up that log in front of this." Near them lay the stem of an oak that had fallen years before. All the boughs had decayed and were gone, so it was not a very difficult task to drag the log in front of them, forming a kind of bar across the alcove. As it was fully a foot in diameter it formed an excellent fortification behind which they lay with their rifles ready. It was indeed a miniature fort, the best that a wilderness could furnish at a moment's notice, and the fighting spirit of the two rose fast. If the enemy came on they were ready to give him a welcome. But the two heard nothing in the dense forest in front of them. The pursuers evidently were aware of the place, in which they had taken refuge, and knew the need of cautious approach. Mexicans do not lack bravery, but both Obed and Ned were sure there would be a long delay. "I think that all we've got to do for the present," said Obed, "is to watch the woods in front of us, and see that none of them sneaks up near enough for a good shot." Nearly an hour passed, and they neither saw nor heard anything in the forest. Then there was a rushing sound, a tremendous impact in front of them and something huge bounded and bounded again among the bushes. It was a great rock that had been rolled over the cliff above, in the hope that it would fall upon them, but the arch of stone over their heads was too deep. It struck fully five feet in front of them. Both were startled, although they knew that they were safe, and involuntarily they drew back.