Routes In'a l'anerma.—(1.) In the opinion of Lull and Menocal, who surveyed this route in 1875, a sea-level canal would not prove profitable; but they made a project for a lock-canal. Starting from the bay of Colon, the route crosses the Chagres river at Matachin throng]] a high aqueduct, and reaches the summit level at an elevation of 124.6 ft. above the sea. A darn extending between the rocky shores of the Chagres riser would supply the canal A•ith nearly 35,000,000 cubic ft. of water per day through a subterranean duct 13,120 ft. long. The canal crosses the Cordilleras through Culebra pass, enters the valley of the Rio Grande river, deflects to the right, and enters the harbor of Panama c. of the terminus of the Panama railroad. A. new channel would be made for the Rio Grande river, and a canal to drain its eastern affluents. Thirty-eight curves, sonic having as short a radips as 2,493 ft., and 25 locks, would be necessary.' The total excavation is estimated at 48,397,000 cubic yds., and the cost at $90,000,000. The length would be 45.45 m., and the time of passage 2.5 days. Menocal considers the Nicaragua route more desirable than this. (2.) Messrs. Wyse and Ileclus, accom panied by explorers and engineers, located a route for a sea-level canal, which follows substantially the line of the Panama railroad. It was after M. de Lesseps had been convinced of the feasibility of a tide-level canal at this point that the invitations were sent out which resulted in the Paris congress. Beginning at the town of Colon, or .Aspinwall, on the bay of Simon, the canal crosses the marsh of Hindi, CIII'VCS twice, and reaches the Chagres river. which it intersects several times and follows to Matachin. It then enters the valley of the Obispo, pierces the mountain through a tunnel 25.263, ft. long, occupies the Rio Grande valley, and terminates in the gulf of Panama. The length of this route is 46.6 m., and there are 13 curves. It uses the river beds the whole distance, and would drain the valleys. A lateral canal would be built at Mat a chin. on account of a fall of 49.2 ft., to conduct the water of the Chagres into the canal; a number of such cuttings are neeessitatei by the rapids and the heavy rain-folls, which produce destructive floods. The depth of the canal at the eastern extremity is 27.9 ft. below mean tide, mid at the western 23.9 ft. below the lowest neap tide. The canal is 65.6 feet wide at the bottom, expanding near the ends to 328 feet. A cross section of the tunnel is 78.7 ft. wide at mean tide, is shaped above the water like a Gothic arch, and ends in a circular arch the highest point of which is 111.5 ft. above the water. To allow vessels to pass sack other, the canal will be widened at intervals of about 5.6 miles. No rise of water exceeding 19i- ft. is anticipated. Sudden inundations would be prevented by dams in the upper Chagres .valley, forming natural reservoirs from which the flow of water could be regulated to a considerable extent. A sea-wall 2,788 ft. long would render the bay of Simon serviceable, while a channel at the western end would be protected by walls, the material for which would be obtained by the rock cuttings. The earth near the ends can be removed by dredging. It was calculated that it would be necessary to excavate 36,625,000 cubic yards of rock and 25,296,000 cubic yards of earth. Wyse and Reclus estimate the cost at $95,600,000. (3.) A project for a lock-canal, presented by the same engineers, contemplated the construction of dams in the Chagres and Rio Grande rivers, forming two lakes, connected by a cutting, whose maximum depth would be 236.2 feet. This would form a plane 78.7 ft. above tide water, 25.48 in. long, 13.66 m. from Colon, and 7.45 m, from Panama, to each of which ports the descent would be made through five locks. The calculated cost is $85,600,000; the total excavation, 15,696,000 cubic yds. ; the length, 45.36 m.; and the time of pas sage, 2 days.
Routes via projects were presented. (4.) The first was elaborated by Messrs. Lull and Menocal, and based upon surveys made in 1872-73 at the expense of the U. S. government. This plan was favored by the American representatives and by a number of French engineers, and is the route most popular among the Ameri can people. The eastern extremity is at the harbor of Greytown, and the western at the harbor of Brito. Starting from Greytown, the canal is constructed, partly by exca vation and partly by dikes, on the left bank of the San Juan river to'the mouth of the San Carlos, a distance of 43.5 miles. Here a dam is thrown across the San Juan, which flows through a rocky valley, producing slack-water navigation 63.38 in. to the lake of Nicaragua. This lake, situated 107 ft. above the sea-level, having a length of 109.35 m. and a breadth of 84.78 m., forms a large natural reservoir. Flom 50 to 60 m. of the route will be across the lake;. sonic dredging, however, will be necessary. The western section starts from the lake near the mouth of the Rio del :Medio, enters the Rio Grande !river 4.97 in. from the lake, where it receives the waters of the Rio del Medici. and crosses the Rivas pass. At this point a stream called the Chicolata becomes an affluent, and finally the canal enters the valley of the Rio Grande river, and terminates near its mouth. The total length is 180 m., of which but 62 in. are artificial. A bar of sand
would be removed from the mouth of the harbor at Greytown, and the deposition of silt prevented by turning the San Juan river into the Colorado. At the harbor of Brito a breakwater would be built, and a jetty to keep out the silt from the Rio Grande river. Ten locks will be required each side of the lake. The western section passes through volcanic mountains, but no great difficulty in construction is anticipated. Blasting will be necessary to form a channel at the entrance of the canal to the lake and in the Rivas pass. The dimensions proposed are: depth, 26i ft.; breadth at bottom, 71.2 ft; breadth at water-level, 150.9 ft.; and, in rock, 59.7 ft. at the bottom, and 89.9 ft. at the water-level. The total material excavated by blasting, dredging, and digging amounts to 62,700,000 cubic yds., and the total cost is calculated to he $52,577,718, or, adding 25 per cent to cover errors and contingencies, $65,722,147. Time required for transit, 4+ days. (5.) The second project, that of 'M. Mancha, is quite different from the American. The chief feature is to preserve the level of the lake throughout the major part of the San Juan river by the construction of a damn. To build the western section, he proposed to cut Guyscoyal pass, and convert the valley of the Rio Grande river into a lake by a dam at La Flor 1319 ft. long, and supporting 65.6 ft. of water. The descent to the harbor of Brito would be made by locks. The chain of two. artificial lakes and one natural would have a length of 147.26 in., while the total length of the canal would be 182.4 miles. This route requires the excavation of 36,240,000 cubic yds. of earth and rock, the cost is calculated at $72.400,000, the time at 4+ days, and 14 locks must be built. . (6) The Tehuantepec route, submitted by M. de Garay, is located in 31exican terri tory, and connects the bay of Vera Cruz with the gulf Of Tehuantepec. The land is level and low, except a narrow ridge of the Cordilleras on the Pacific coast. The water from a number of large streams would be utilized. The dimensions proposed would not admit of the passage of the largest ships. The length would be 174 m.; the time of passage, 12 days. One hundred and twenty locks would be necessary. (7) The Atrato Napipi route, surveyed by Selfridge and Collins, starts from the gulf of Darien and passes up the Atrato river at its level to the mouth of the Napipi, a distance of 149 miles. The minimum depth of the river is 25.6 feet. From this point the air-line dis tance to the bay of Chiri-Chiri is 27.95 miles. Dredging would be done for 5.6 in. in the Napipi river, under which the canal afterwards passes by means of a tunnel; it terminates in a basin 18.7 ft. above mean tide after passing through 5.6 m. of. tunnel in the mountains near the Pacific. Two locks. connect the basin with the bay of Chili Chid, and jetties must be built and bars cut through in the harbors. The cost is estimated at $98,200,000, the time of passage at three days. and the total length at 180 wiles. (S) The San Bias route was explored by McDougal in 1864, at the expense of Mr. Kelley, of Philadelphia, and was afterwards surveyed by Selfridge. At this point, the narrowest part of the isthmus, the width is but 31 miles. A tide-level canal is impracticable, owing to the height of the Cordilleras and the location of the streams. Upon the authority of Wyse and Recius, the length of the•catial would be 32.9 m., and about 10 out of the 24.85 m. of excavation would be tunneling. An excavation of 44,473,000 cubic yds. would be required, at a cost of $95,000,000, while the passage would take one day, and there would be one sea-lock. In addition to the plans outlined above, which were the more important ones presented to the congress, a number of modifications of them, as well as independent routes, have been proposed. In a paper rend before the society of arts, London, rapt. Bedford Phil, R.N., 3I.P.-a gentleman who has passed through Nicaragua six times, and surveyed the major part of both coast- • lines of the isthmus—pronounces the improvement of the harbor at Greytown the most difficult part of the work on the Nicaragua route. The entrance to the harbor is alternately choked up with sand by a storm, and opened by a Hood in the San Juan river. To avoid this harbor, which he thinks would "completely swamp the enter prise," he .proposes a route starting from Pim's bay, 40 m. n. of Greytowu, and ending at the port of Realejo, on the Pacific. This route would be 290 in. long, and would include 85 m. of navigation on the lake of Nicaragua and 40 in. on lake Managua. The chief feature of the plan is the proposal to make the depth of the canal only 8 ft., and to transport the vessels upon "pontoons by the process which has been successfully used in the Victoria docks (London) for years." He suggests that a railroad should first be built connecting with steamboats on the lakes as an auxiliary to the construction, and as liable to afford a valuable knowledge of the district. The captain estimates the cost at an average of about $100,000 per mile, or a total of $30,000,000, and proposes that the governments of England, France, and the United States should each guarantee one per cent upon the capital, and that a five-acre plot of land should be given with each $50 share.