"Sit down—stay quiet!" commanded the other quickly. "They will return in a half-hour, sir——"
"Then I'll be on my way," broke in Norton drily, "for I have other business than watching birds, sir."
He turned, when the stranger set down the paper and board, on which only a few sketchy lines were visible, and caught at his arm.
"Pardon, sir—one moment! Are you lately from Louisiana? Do you know that country well?"
"I've lived there all my life, practically," said Norton. "Why?"
"Well"—and the other seemed to forget his birds temporarily—"I was but a child when I went to France, and last year I heard a monstrous strange story of Upper Louisiana, which I have never been able to authenticate. I met one of the men who had been on Colonel Burr's ill-fated expedition, and he assured me that on the banks of the Missouri there is a mountain of salt——"
"Travellers' tales," laughed Norton, but the other continued quickly:
"Wait, sir! He also stated very decidedly that had Colonel Burr succeeded in his venture, he would have been joined by a great tribe of Indians. This tribe inhabit a country of some nine hundred square miles, around the salt mountain, fight always on horseback, and are armed with the short Spanish carbines——"
"My dear sir," inquired Norton in frank wonder, "are you in earnest?"
"Of course I am!" And indeed there was no mistaking the eager interest of the stranger's handsome face. "I am a student of ornithology, sir—that is, I pursue the study in my spare time—but I am also keenly interested in such matters of ethnology, and if you could enlighten me as to this Indian tribe, I would appreciate it. You seem a person of no little refinement and culture——"