Complex sentence: Some time afterward, the narrator hears a rumor that Bartleby had worked in a dead letter office, and reflects that dead letters would have made anyone of Bartleby's temperament sink into an even darker gloom.
Split into simpler sentences: Some time afterward, the narrator hears a rumor to that Bartleby had worked in a dead letter office. The narrator reflects that dead letters would have made anyone of Bartleby's temperament sink into an even darker gloom.