In 1755, the Portuguese capital, Lisbon, was almost totally destroyed by an earthquake and the resulting tsunamis, and by fire. Perhaps 90,000 people died and 85% of buildings were shattered, including the Royal Ribeiro Palace, home to the archives of all Portuguese exploration in and around the East Indies, including the voyages of Vasco da Gama. All records were lost. Did the Portuguese send voyages of exploration, secretly, across the treaty...