I could hear the tick-tack of his iron every time he knocked one of the spikes in.

Of course he went higher every time.

They were just far enough apart for a man to get his foot on from one to another.

As he went up he had one end of the coil of the rope round his wrist.

When he got to the top he was to draw it up to fasten to the top spike, and lower himself down by it to the ground on the other side.