At least, his guess concerning their camping in that valley turned out quite true, for when they were half-way across the basin Zander gave the order to pull up.

They were going to enjoy a hunter's feast that night, for the first time on the trip. Zander had managed to creep up on a feeding antelope, by keeping to leeward of the timid animal, and with a remarkably long and clever shot dropped his quarry.

So they expected to eat fresh venison to their hearts' content, and the three boys anticipated a delightful meal.

"Say, Frank, they're scooping down closer right now," Lanky observed, as he caught hold of his chum. "I wonder if they smell our fresh meat and hope to get the leavings of our supper."

Frank, however, shook his head skeptically.

"More than likely they've sighted some sort of carrion lying in the valley here, and are making for that. You can see that they keep wheeling in big circles over a spot lying to the north of us, and not more than a couple of hundred yards away from here."

"I'm glad it's to the north," said Paul; "for if there's a dead animal over yonder, so long as the breeze keeps in the southwest we're not going to hold our breath half the night. See! One of the big birds has dropped down to the ground. What monster wings they have; and they keep flapping them up and down as if ready for a scrap as they hop around sideways."

"Zander told me these vultures are about four feet in length from beak to the end of their tails, but that they have a wing spread of over ten feet!"

"Some birds, I'd say," replied Paul. Lanky was only grinning as he eagerly watched the other scavengers of the air drop down and commence to copy the gyrations of the first pilgrim.

"Gee! I'd sure like to try it out," Frank heard him mutter. But what Lanky meant he did not bother to explain, and Frank in the rush of other things forgot to ask him.