Bridle bits rattled, and metal clanked against metal.
"I suppose the circle is complete," said Ned.
"Looks like it," said Crockett, "but we've got our cattle to eat an' water to drink an' only a direct attack in force can take us.

They can bang away with their cannon till next Christmas an' they won't shake our grip on the Alamo." The night was fairly dark, and an hour later Ned heard a whistle.
Crockett heard it, too, and stiffened instantly into attention.
"Did that sound to you like a Mexican whistling ?" he asked.
"No, I'd say it came from American lips, and I'd take it also for a signal." "An' so it is.

It's just such a whistle as hunters use when they want to talk to one another without words.

I've whistled to my pardners that way in the woods hundreds of times.

I think, Ned, that some Texans are at hand waitin' a chance to slip in." Crockett emitted a whistle, low but clear and penetrating, almost like the song of a night bird, and in a half minute came the rejoinder.