A noise in the outer office recalled Livingstone from his reverie.

He aroused himself, almost with a start, and glanced at the gilt clock just above the stock-indicator.

He had been so absorbed that he had quite forgotten that he had told the clerks to wait for him.

He had had no idea that he had been at work so long.

He reflected, however, that he had been writing charity-cheques: the clerks ought to appreciate the fact.
He touched a button, and the next second there was a gentle tap on the door, and Clark appeared.