No treasure yarn is the real thing unless it glitters with ducats, ingots, and pieces of eight, which means that in the brave days when riches were quickest won with cutlass, boarding pike, and carronade, it was Spain that furnished the best hunting afloat. For three centuries her galleons and treasure fleets were harried and despoiled of wealth that staggers the imagination, and their wreckage littered every ocean. English sea rovers captured many millions of gold and silver, and pirates took their fat shares in the West Indies, along the coasts of America from the Spanish Main to Lima and Panama, and across the Pacific to Manila. And to-day, the quests of the treasure seekers are mostly inspired by hopes of finding some of the vanished wealth of Spain that was hidden or sunk in the age of the Conquistadores and the Viceroys. Of all the argosies of Spain, the richest were those plate fleets which each year carried to Cadiz and Seville the cargoes of bullion from the mines of Peru, and Mexico, and the greatest treasure ever lost since the world began was that which filled the holds of the fleet of galleons that sailed from Cartagena, Porto Bello, and Vera Cruz in the year 1702. What distinguishes this treasure story from all others is that it is not befogged in legend and confused by mystery and uncertainty. And while ships' companies are roaming the Seven Seas to find what small pickings the pirates and buccaneers may have lifted in their time, the most marvelous Spanish treasure of them all is no farther away than a harbor on the other side of the Atlantic. At the bottom of Vigo Bay, on the coast of Spain, lies that fleet of galleons and one hundred millions of dollars in gold ingots and silver bars. This estimate is smaller than the documentary evidence vouches for. In fact, twenty-eight million pounds sterling is the accepted amount, but one hundred million dollars has a sufficiently large and impressive sound, and it is wise to be conservative to the verge of caution in dealing with lost treasure which has been made so much more the theme of fiction than a question of veracity. After escaping the perils of buccaneer and privateer and frigate, this treasure fleet went down in a home port, amid smoke and flame and the thunder of guns manned by English and Dutch tars under that doughty admiral of Queen Anne, Sir George Rooke. It was the deadliest blow ever dealt the mighty commerce of Spain during those centuries when her ruthless grasp was squeezing the New World of its riches.