was unable to guess its meaning.

Fearing that further delay to light our fire might bring disaster upon
us, I told Corporal Frank to kindle it. He ascended the chimney,
lighted a few splinters of pitch-pine and placed them upon the roof,
and as soon as they were well lighted added to them half a dozen
billets of wood which Sergeant Cunningham passed up to him. Soon a
brilliant blaze was leaping upward, and, being reflected strongly by
the white sandstone of the overhanging cliff, lighted the whole space
about the cabin.

As soon as Frank descended to the floor we gazed long and anxiously
out of the windows. Everything about us was now plainly visible to our
eyes, and we felt sure our movements could not be seen by the Navajos.
To the east all was silent, and for a long while we saw nothing in
that direction to suggest a lurking foe. To the west we could see no
enemy, but the same mysterious sound of crushing and grinding came to
our ears. What could it be, and what did it threaten? Adjusting my
field-glass I looked from my window in the direction of the puzzling
sound, and on the farther edge of the opening, near the wood, saw a
log about three feet in diameter and twenty-five or more in length
slowly rolling towards us, propelled by some unseen force.

Passing the glass to the sergeant, I said: "The Indians seem to be
rolling a log in our direction. What do you think of it?"

"I think it's easy to understand, sir," replied the sergeant, after a
long look. "That log is a movable breastwork, which can be rolled to
our door."