The great isthmus was, however, further explored by the Spanish government for its own purposes; the recesses were traversed, and the lines of communication which we know to-day were then noted.

In addition to the fact that comparatively little was explored north or south of that which early became the main highway, the Panama route, there is confirmation here of the truth that Spain concealed and even falsified much of her generally accurately made surveys. No stronger proof of this need be asked than that which Alcedo gives in connection with the proposal by Gogueneche, the Biscayan pilot, to open communication by the Atrato and the Napipi. "The Atrato," says the historian, "is navigable for many leagues, but the navigation of it is prohibited under pain of death, without the exception of any person whatever."

The Isthmus of Nicaragua has always invited serious consideration for a ship canal route by its very marked physical characteristics, among which is chiefly its great depression between two nearly parallel ranges of hills, which depression is the basin of its large lake, a natural and all-sufficient feeder for such a canal.

In 1524 a squadron of discovery sent out by Cortez on the coast of the South Sea, announced the existence of a fresh water sea at only three leagues from the coast; a sea which, they said, rose and fell alternately, communicating, it was believed, with the Sea of the North. Various reconnoissances were therefore made, under the idea that here the easy transit would be established between Spain and the spice lands beyond.

It was even laid down on some of the old maps, that this open communication by water existed from sea to sea; while later maps represented a river, under the name of Rio Partido, as giving one of its branches to the Pacific Ocean and the other to Lake Nicaragua. An exploration by the engineer, Bautista Antonelli, under the orders of Philip II., corrected the false idea of an open strait.

In the eighteenth century a new cause arose for jealousy of her neighbors and for keeping her northern part of the isthmus from their view. In the years 1779 and 1780 the serious purposes of the English government for the occupancy of Nicaragua, awakened the solicitudes of the Spanish government for this section. The English colonels, Hodgson and Lee, had secretly surveyed the lake and portions of the country, forwarding their plans to London, as the basis of an armed incursion, to renew such as had already been made by the superintendent of the Mosquito coast, forty years before, when, crossing the isthmus, he took possession of Realejo, on the Pacific, seeking to change its name to Port Edward. In 1780, Captain, afterward Lord Nelson, under orders from Admiral Sir Peter Parker, convoyed a force of two thousand men to San Juan de Nicaragua, for the conquest of the country.

In his dispatches, Nelson said: "In order to give facility to the great object of government, I intend to possess the lake of Nicaragua, which, for the present, may be looked upon as the inland Gibraltar of Spanish America. As it commands the only water pass between the oceans, its situation must ever render it a principal post to insure passage to the Southern Ocean, and by our possession of it Spanish America is severed into two."

The passage of San Juan was found to be exceedingly difficult; for the seamen, although assisted by the Indians from Bluetown, scarcely forced their boats up the shoals. Nelson bitterly regretted that the expedition had not arrived in January, in place of the close of the dry season. It was a disastrous failure, costing the English the lives of one thousand five hundred men, and nearly losing to them their Nelson.

At this period, Charles III., of Spain, sent a commission to explore the country. These commissioners reported unfavorably as regarded the route; but fearing further intrusion from England, forbade all access to the coast; even falsifying and suppressing its charts and permanently injuring the navigation of the San Juan and the Colorado by obstructions in their beds.

It is, however, a relief here to learn that when Humboldt visited the New World, he could say: "The time is passed when Spain, through a jealous policy, refused to other nations a thoroughfare across the possessions of which they kept the whole world so long in ignorance. Accurate maps of the coasts, and even minute plans of military positions, are published." It is also true that the Spanish Cortes, in 1814, decreed the opening of a canal, a decree deferred and never executed.