Hark, did you hear that noise ?" All of them listened.

It sounded at first like the cow's horn, but they concluded that it was the rumble, made by sliding snow, which would be sending avalanches down the slopes all through the night.
"Are you going out again, Mr.Shepard ?" Dick asked.
"I think not, sir.

Colonel Winchester wants me to stay here, and, even if the enemy should come, we'll be ready for him." They did not speak again for a while and they heard several times the noise of the sliding snow.

Then they heard a note, low and deep, which they were sure was that of the cow's horn, or its echo.

It was multiplied and repeated, however, so much by the gorges that it was impossible to tell from what point of the compass it came.
But it struck upon Dick's ears like a signal of alarm, and he and all the others of the picket stiffened to attention..