âIf you swim to latitude Fifty North, longitude Forty West (that is magic), you will find, sitting _on_ a raft, _in_ the middle of the sea, with nothing on but a pair of blue canvas breeches, a pair of suspenders (you must _not_ forget the suspenders, Best Beloved), and a jack-knife, one ship-wrecked Mariner, who, it is only fair to tell you, is a man of infinite-resource-and-sagacity.â