After a stay of seventeen years in China, Marco and his companions resolved to make an attempt to return to their native land. Kublai Khan, however, was unwilling to part with them; and they owed their final release to a circumstance wholly unexpected. An embassy from Persia had visited Pekin, and had selected one of Kublai's grand-daughters for the wife of their prince. They set out with her on their journey to Persia, but, after meeting with incredible obstacles, were obliged to return to the Chinese capital. Marco had, at this time, just returned from a voyage among the islands of the Indian Sea, and had laid before the khan his observations upon the feasibility of navigation in those waters. The ambassadors sought an interview with Marco Polo, and found that they had all a common interest,--that of getting away as speedily as possible. The khan was forced to facilitate the departure of the envoys, though it deprived him of his friends the Venetians. Preparations were made upon a grand scale for the expedition. Fourteen four-masted ships, a part of them with crews of two hundred and fifty men, were equipped and victualled for two years. The khan bade the Polo party an affectionate adieu, making them his ambassadors to the principal courts of Europe, and extorting from them a promise to return to his service after a visit to their own country. Thus honorably dismissed, they set sail from the port of Amoy, in 1291. They coasted along the shores of Cochin China, and came in sight of the islands of Borneo and Java, though they did not land there. At the island of Bintan, near the Straits of Malacca, they obtained some knowledge of the kingdom of the Malays at the southern extremity of the peninsula. They landed upon Sumatra, and visited many parts of the island. Marco thus speaks of one branch of the trade of the inhabitants:--"It should be known that what is reported respecting the mummies of pygmies sent to Europe from India is only an idle tale, these pretended human dwarfs being manufactured in this island in the following manner. The country produces a large species of monkey having a countenance resembling that of a man. The Sumatrans catch them, shave off their hair, dry and preserve their bodies with camphor and other drugs, and prepare them generally so as to give them the appearance of little men. They then pack them in wooden boxes and sell them to traders, by whom they are vended for pygmies in all parts of the world. But there are no such things as pygmies in India or anywhere else. It is mere monkey-trade."