Thus the stick of timber rested in a long loop, one end of which led to the invisible horse, and the other Jim made fast to the top of the pile.

He did so by jamming into another log the steel swamp-hook with which the chain was armed.

When all was made fast, the horse started.
"She's a bumper!" said Bob.

"Look out, Mike!" The log slid to the foot of the two parallel poles laid slanting up the face of the pile.

Then it trembled on the ascent.