Whoever built the Octagon might have constructed it especially for this sort of crisis. Its walls had grooves at regular intervals which were just right for the hands and feet, and it wasn’t very long before I was parked up on the roof beside the Right Hon. , gazing down at one of the largest and shortest-tempered swans I had ever seen. It was standing below, stretching up a neck like a hosepipe, just where a bit of brick, judiciously bunged, would catch it amidships.

I bunged the brick and scored a bull’s-eye.

The Right Hon. didn’t seem any too well pleased.

“Don’t tease it!” he said.

“It teased me,” I said.