At the age of fourteen or just as the War of 1812 was fairly under way, Nathaniel shipped on board of a coasting vessel which ran to ports between Maine and New York, and continued in this service until he was eighteen, when he was appointed second mate of the brig _Hersilia_, bound down somewhere about Cape Horn on a sealing voyage. These sealing expeditions were also at that period more or less voyages of discovery. For years there had been rumors of a mythical island called Auroras, embellished with romance and mystery by the whalers of Nantucket, New Bedford, and New London, and described as lying away to the eastward of the Horn, concerning which no forecastle yarn was too extravagant for belief. Whaling captains by the score had spent days and weeks in unprofitable search for it. On this voyage Captain J. P. Sheffield, of the _Hersilia_, landed at one of the Falkland Islands, where he left his second mate and one sailor to kill bullocks for provisions, and then sailed away in search of the fabled island. Young Nat Palmer proceeded to capture and slay bullocks, and when, after a few days, a ship hove in sight, he piloted her into a safe anchorage, and supplied her with fresh meat. This vessel proved to be the _Espirito Santo_, from Buenos Ayres, and the captain informed Nat that he was bound to a place where there were thousands of seals, and where a cargo could be secured with little effort, but he declined to disclose its position. The mind of the young sailor naturally turned to the magic isle of Auroras, where, according to the saga preserved beside the camp-fires of corner grocery stores in New England whaling towns, silver, gold, and precious gems lay scattered along the beach in glittering profusion, the treasure of some huge galleon, wrecked and broken up centuries ago, when Spain was powerful upon the sea.