Nicaragua, Panama or Darien, and in 1551 the Spanish historian F. L. de Gomara submitted a memorial to Philip II. urging in forcible language that the work be undertaken without delay. But the project was opposed by the Spanish Government, who had now concluded that a monopoly of communication with their possessions in the New World was of more importance than a passage by sea to Cathay. It even discouraged the improvement of the communications by land. To seek or make known any better route than the one from Porto Bello to Panama was forbidden under penalty of death. For more than two centuries no serious steps were taken towards the construction of the canal, if exception be made of William Paterson’s disastrous Darien scheme in 1698. In 1771 the Spanish government, having changed its policy, ordered a survey for a canal at Tehuantepec, and finding that line impracticable, ordered surveys in 1779 at Nicaragua, but political disturbances in Europe soon prevented further action. In 1808 the isthmus was examined by Alexander von Humboldt, who pointed out the lines which he considered worthy of study. After the Central American republics acquired their independence in 1823, there was a decided increase of interest in the canal question. In 1825 the Republic of the Centre, having received applications for concessions from citizens of Great Britain, and also from citizens of the United States, made overtures to the United States for aid in constructing a canal, but they resulted in nothing. In 1830 a concession was granted to a Dutch corporation under the special patronage of the king of the Netherlands to construct a canal through Nicaragua, but the revolution and the separation of Belgium from Holland followed, and the scheme fell through. Subsequently numerous concessions were granted to citizens of the United States, France and Belgium, both for the Nicaragua and the Panama lines, but with the exception of the concession of 1878 for Panama and that of 1887 for Nicaragua, no work of construction was done under any of them.
Knowledge of the topography of the isthmus was extremely vague until the great increase of travel due to the discovery of gold in California in 1848 rendered improved communications a necessity. A railroad at Panama and a canal at Nicaragua were both projected. Instrumental surveys for the former in 1849, and for the latter in 1850, were made by American engineers, and, with some small exceptions, were the first accurate surveys made up to that time. The work done resulted in geographical knowledge sufficient to eliminate from consideration all but the following routes: (1) Nicaragua; (2) Panama; (3) San Blas; (4) Caledonia Bay; (5) Darien; (6) Atrato river, of which last there were four variants, the Tuyra, the Truando, the Napipi and the Bojaya. In 1866, in response to an inquiry from Congress, Admiral Charles H. Davis, U.S. Navy, reported that “there does not exist in the libraries of the world the means of determining even approximately the most practicable route for a ship canal across the American isthmus.” To clear up the subject, the United States government sent out, between 1870 and 1875, a series of expeditions under officers of the navy, by whom all of the above routes were examined. The result was to show that the only lines by which a tunnel could be avoided were the Panama and the Nicaragua lines; and in 1876 a United States Commission reported that the Nicaragua route possessed greater advantages and offered fewer difficulties than any other. At Panama the isthmus is narrower than at any other point except San Blas, its width in a straight line being only 35 m. and the height of the continental divide is only 300 ft., which is higher than the Nicaragua summit, but less than half the height on any other route. At Nicaragua the distance is greater, being about 156 m. in a straight line, but more than one third is covered by Lake Nicaragua, a sheet of fresh water with an area of about 3000 sq. m. and a maximum depth of over 200 ft., the surface being about 105 ft. above sea-level. Lake Nicaragua is connected with the Atlantic by a navigable river, the San Juan, and is separated from the Pacific by the continental divide, which is about 160 ft. above sea-level. At Nicaragua only a canal with locks is feasible, but at Panama a sea-level canal is a physical possibility.
By the Clayton-Bulwer Treaty of 1850 with Great Britain, by the treaty of 1846 with New Granada (Colombia), Article XXXV., and by the treaty of 1867 with Nicaragua, Article XV., the United States guaranteed that the projected canal, whether the Panama or the Nicaraguan, should be neutral, and, furthermore, that it be used and enjoyed upon equal terms by the citizens of both countries in each case. A modification of the Clayton-Bulwer Treaty being necessary to enable the United States to build the canal, a treaty making such modifications, but preserving the principle of neutrality, known as the Hay-Pauncefote Treaty, was negotiated with Great Britain in 1900; it was amended by the United States Senate, and the amendments not proving acceptable to Great Britain, the treaty lapsed in March 1901. A new treaty, however, was negotiated in the autumn, and accepted in December by the U.S. Senate.
The completion of the Suez Canal in 1869, and its subsequent success as a commercial enterprise, drew attention more forcibly than ever to the American isthmus. In 1876 an association entitled “Société Civile Internationale du Canal Interocéanique” was organized in Paris to make surveys and explorations for a ship canal. An expedition under the direction of Lieut. L. N. B. Wyse, an officer of the French navy, was sent to the isthmus to examine the Panama line. In May 1878 Lieut. Wyse, in the name of the association, obtained a concession from the Colombian government, commonly known as the Wyse Concession. This is the concession under which work upon the Panama Canal has been prosecuted. Its first holders did no work of construction.
In May 1879 an International Congress composed of 135 delegates from various nations—some from Great Britain, United States and Germany, but the majority from France—was convened in Paris under the auspices of Ferdinand de Lesseps, to consider the First Panama Companybest situation for, and the plan of, a canal. After a session of two weeks the Congress decided that the canal should be at the sea-level, and at Panama. Immediately after the adjournment of the Congress the Panama Canal Company was organized under a general law of France, with Lesseps as president, and it purchased the Wyse Concession at the price of 10,000,000 francs. An attempt to float this company in August 1879 failed, but a second attempt, made in December 1888, was fully successful, 6,000,000 shares of 500 francs each being sold. The next two years were devoted to surveys and examinations and preliminary work upon the canal. The plan adopted was for a sea-level canal having a depth of 295 ft. and bottom width of 72 ft., involving excavation estimated at 157,000,000, cub. yds. The cost was estimated by Lesseps in 1880 at 658,000,000 francs, and the time required at eight years. The terminus on the Atlantic side was fixed by the anchorage at Colon, and that on the Pacific side by the anchorage at Panama. Leaving Colon, the canal was to pass through low ground by a direct line for a distance of 6 m. to Gatun, where it intersected the valley of the Chagres river; pass up that valley for a distance of 21 m. to Obispo, where it left the Chagres and ascended the valley of a tributary, the Cumacho; cut through the watershed at Culebra, and thence descend by the valley of the Rio Grande to Panama Bay. Its total length from deep water in the Atlantic to deep water in the Pacific was about 47 m. It was laid out in such a way as to give easy curvature everywhere; the sharpest curve, of which there was but one, had a radius of 6200 ft., four others had a radius of 8200 ft., and all others had a radius of 9800 ft. or more. To secure this it was necessary to select a point for crossing the watershed where the height was somewhat greater than that of the lowest pass. The line was essentially the same as that followed by the Panama railroad, the concession for which granted a monopoly of that route; the Wyse Concession, therefore, was applicable only upon condition that the canal company could come to an amicable agreement with the railroad company.
The principal difficulties to be encountered in carrying out this plan consisted in the enormous dimensions of the cut to be made at Culebra, and in the control of the Chagres river, the valley of which
