The cutting of the isthmus between North and South America was the dream of navigators and engineers from the time when the first discoverers ascertained that nature had neglected to provide a passage. Yet the new continent which so unexpectedly blocked the way of Columbus in his search for the Indies opposed for centuries an insurmountable barrier to the commerce of the East and the West. The piercing of the isthmus always seemed a perfectly feasible undertaking, but the difficulties in the way proved greater than at first sight appeared. There were (1) the physical or engineering problems to be solved, and (2) the diplomatic complications regarding the control of the canal in peace and its use in war. The weakness of the Spanish-American states, whose territories embraced the available routes, and their recognized inability either to construct or protect a canal made what might otherwise have been merely a question of domestic economy one of grave international import. In this respect, as in others, the problem presented the same features as the Suez canal. To meet these difficulties three plans were successively developed during the nineteenth century: (1) a canal constructed by a private corporation under international control, (2) a canal constructed by a private corporation under the exclusive control of the United States, and (3) a canal constructed, owned, operated, and controlled by the United States as a government enterprise. The Clayton-Bulwer treaty provided for the construction of a canal in accordance with the first plan; several unsuccessful attempts were made to raise the necessary capital under the second plan; while the third plan was the one under which the gigantic task was actually accomplished. The comparative merits of the Nicaragua and Panama routes long divided the opinion of experts. American engineers generally favored that through Nicaragua. The length of the Nicaragua route, from Greytown on the Atlantic to Brito on the Pacific by way of the San Juan river and through Lake Nicaragua, is about 170 miles. The elevation of the lake above the sea is about 110 feet. Its western shore is only twelve miles from the Pacific, with an intervening divide 154 feet above the sea. From the southeast corner of the lake flows the San Juan river, 120 miles to the Atlantic, with an average fall of about 10 inches to the mile. The serious objections to this route are: (1) the lack of harbors at the terminals, Brito being a mere indentation on the coast, rendering the construction of immense breakwaters necessary, while at Greytown the San Juan broadens out into a delta that would require extensive dredging; and (2) the enormous rainfall at Greytown, exceeding that known anywhere else on the western continent--nearly 25 feet.