Men have been known, both in the tropics and in the temperate zone, to sit up half the night ‘swapping yarns’. This, however, is but one yarn, yet with interruptions affording some measure of relief; and in regard to the listeners’ endurance, the postulate must be accepted that the story was interesting. It is the necessary preliminary assumption. If I hadn’t believed that it was interesting I could never have begun to write it. As to the mere physical possibility we all know that some speeches in Parliament have taken nearer six than three hours in delivery; whereas all that part of the book which is Marlow’s narrative can be read through aloud, I should say, in less than three hours