The policy of Philip was continued for about two centuries, although in the reign of his father many efforts had been made in the direction of a ship waterway across the Isthmus. In fact, ships crossed the Isthmus nearly four centuries before the completion of the canal. About 1521 Gil Gonzales was sent to the New World to seek out a strait through the Isthmus. He sailed up and down the Central American coast, entering this river and that, but failing of course to find a natural waterway. Not to be outdone, he decided to take his two caravels to pieces and to transport them across the Isthmus. He carried them on the backs of Indians and mules from the head of navigation on the Chagres River to the ancient city of Panama. There he rebuilt them and set out to sea, but they were lost in a storm. Still determined to make the most of his opportunities, Gonzales built others to take their places and with these made his way up the Pacific coast through the Gulf of Fonseca to Nicaragua, where he discovered Lake Nicaragua. A few years later another explorer made a trip across Lake Nicaragua and down the San Juan River to the Atlantic. Cortez, the conquistador of Mexico, at one time was ordered to use every resource at his command in a search for the longed-for strait. He did not find it, but he did open up a line of communication across the Isthmus of Tehauntepec, following practically the same line as was afterwards followed by Eads with his proposed ship railway. From those days to the time when the United States decided that the canal should be built at Panama and that it should be made a national undertaking, one route after another was proposed. In 1886, immediately after the French failure, the Senate requested the Secretary of the Navy to furnish all available information pertaining to the subject of a canal across the Isthmus, and Admiral Charles H. Davis reported that 19 canal and 7 railway projects had been proposed, the most northerly across the Isthmus of Tehauntepec and the most southerly across the Isthmus of Panama at the Gulf of Darien, 1,400 miles apart. Eight of these projects were located in Nicaragua.