Many people think that salvaging artifacts from the sunken Titanic amounts to something ghoulish, like grave robbing. “The Wreck of the Titanic ,” now on view at the Maritime Museum in Greenwich, England, is the first exhibit of just such items: clothes, machinery, dishes, and papers, stolen back from the ocean after more than eighty years. According to the deep-sea explorers, corpses didn’t last. Only the tumble of things that amused or comforted them while they were alive did. Of course it is eerie to see something ephemeral like a row of cigarettes emerge unscathed when so many perfectly good people did not, and so this firsthand exhibit, a fitting memorial to the eeriest of all ships, actually only deepens the mysteries surrounding the Titanic . (National Maritime Museum, Greenwich, England SE10 9NF, 011-44-81-858-4422.)