THE MEDLEVAL MAXIM OF SECRET TRADE 199 down, but the methods of exploration had profoundly changed. Mediaeval sea-trade rigorously enforced the maxims of secret commerce. Venice, like Carthage of old, punished with death the revealer of a maritime route, and the export of charts of discovery was a cap- ital crime. The Adriatic merchants raised a wall of A SCENE IN INDIA, NEAR BOMBAY. mystery between the Mediterranean and the Atlantic. They " laboured to make us strangers to the Great Turk, the Egyptians, and bordering countries, and brought them to that ignorance of our nation, that they thought England to be a town in the kingdom of Lon- don, " wrote Sir William Monson. In 1424 the Doge had considered a copy of the travels of Marco Polo, together with a map (probably the precious Medicean portulan of 1351) as a State gift worthy to accompany
