The minutes expanded into grey immensities, and for a time perhaps he slept....
He woke with a vague impression of remote concussions.

He perceived a rattling of the windows like the quiver of an earthquake, that lasted for a minute or so and died away.

Then after a silence it returned....
Then it died away again.

He fancied it might be merely the passage of some heavy vehicle along the main road.

What else could it be?
After a time he began to doubt whether he had heard this sound.
He began to reason interminably with himself.