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Charles project at the Carnegie Institute involved archiving letters sent from the captain of the research vessel Carnegie in the early part of the 20th century. The ship, built without using any ferrous metal, crisscrossed the globe measuring the earth's magnetic field. Away from home for years at a time, he wrote letters to his wife back home. In some cases, the letters were put into a waterproof barrel and thrown overboard in a shipping lane in the hope, often realized, that some passing ship would pick them up and mail them. All of the envelopes we saw were missing the stamps, which had been appropriated by avid collectors years ago.