It was probably four o'clock in the afternoon when they got ready to start over the plain.
Just as they were mounting they saw a number of horses coming swiftly over the plain toward them.
"Wild horses, I guess," observed the professor.
"No, they ain't, either," returned Lank Edwards, who had been gazing intently at the approaching animals. "They ain't wild horses, nohow, 'cause wild horses ain't likely to have men on their backs, an' these fellers have."
"What!" gasped our hero. "A party of mounted men?"
"That's just what it are," was the reply.
"Let's get under the cover of these trees and wait till they get a little nearer," suggested Jack.
They at once did so.
Ten minutes more and all were satisfied that the horses were mounted.
There were about fifty of them, and at the head of the column were two men in civilized dress.