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Thebes, at the head of the Grand Chain, and Commerce at the foot of it, were towns easily rememberable, as they had not undergone conspicuous alteration. Nor the Chain, either--in the nature of things; for it is a chain of sunken rocks admirably arranged to capture and kill steamboats on bad nights. A good many steamboat corpses lie buried there, out of sight; among the rest my first friend the 'Paul Jones;' she knocked her bottom out, and went down like a pot, so the historian told me--Uncle Mumford. He said she had a gray mare aboard, and a preacher. To me, this sufficiently accounted for the disaster; as it did, of course, to Mumford, who added--