'THERE WASN'T ANY TOP TO IT.

So the carpet's going to fit itself in at the bottom.' Robert sprang to his feet.
'We ought to have--Hullo! an owl's nest.' He put his knee on a jutting smooth piece of grey stone, and reached his hand into a deep window slit--broad to the inside of the tower, and narrowing like a funnel to the outside.
'Look sharp!' cried every one, but Robert did not look sharp enough.

By the time he had drawn his hand out of the owl's nest--there were no eggs there--the carpet had sunk eight feet below him.
'Jump, you silly cuckoo!' cried Cyril, with brotherly anxiety.
But Robert couldn't turn round all in a minute into a jumping position.
He wriggled and twisted and got on to the broad ledge, and by the time he was ready to jump the walls of the tower had risen up thirty feet above the others, who were still sinking with the carpet, and Robert found himself in the embrasure of a window; alone, for even the owls were not at home that day.

The wall was smoothish; there was no climbing up, and as for climbing down--Robert hid his face in his hands, and squirmed back and back from the giddy verge, until the back part of him was wedged quite tight in the narrowest part of the window slit.
He was safe now, of course, but the outside part of his window was like a frame to a picture of part of the other side of the tower.

It was very pretty, with moss growing between the stones and little shiny gems; but between him and it there was the width of the tower, and nothing in it but empty air.