The path was so narrow that, although Roderick walked on the extreme outer edge, Frank's feet now and then brushed against the rock on the opposite side.

Our hero felt his sombrero rise on his head, whenever he looked into the chasm, or allowed himself to reflect how slight an accident might launch him into eternity.

But there was no backing out.

Once on that ledge, a person must go forward; for there was no room to turn around.
After Frank came another of the band, and Johnny followed at his heels.
Archie and his keeper came next, and Arthur and _his_ keeper brought up the rear.

They all rode fearlessly upon the ledge, until it came Arthur's turn, and then was heard a cry of remonstrance.