Note XXXIV-35 — Chapter XXXIV · INTEROCEANIC COMMUNICATION. 1801-1887.

The bottom throughout its length, 8½ metres below the mean level of both oceans; width, 22 metres at bottom, 50 metres at top; except through the Culebra ridge, where the depth will be 9 metres, with the width of 24 metres at bottom and 28 metres at top. It must be observed that the levels of the two oceans are not alike at all times; at Colon the difference in the tides never exceeds 23 inches, whereas in Panamá it is usually 13 ft, and at times nearly 20. This must produce a current in the canal sufficient to impede navigation for several hours at each tide. The great difficulties to overcome are the mountain and the river Chagres. The company contemplated at first to tunnel the mountain, but gave up the plan, and resolved to cut down through the solid strata—fortunately soft and otherwise easy—for a depth of between 300 and 400 ft over a long distance. The next task—by far the most difficult one—is to deal with the eccentricities of the Chagres, which discharges at Matachin a volume of water averaging 100 cubic metres per second, which at low water may sink to 15 or 20 cubic metres, and at flood rise to 500 or 600. Several plans have been contemplated, one of which was to construct an enormous dam at Gamboa, between the Obispo and Santa Cruz hills, 960 metres at the base, 1,960 at the top, with a width at bottom, of 1,000 metres, and a height of 45 metres. But it is understood that the engineers have finally concluded to make no use of the waters of the Chagres, but to change their course and let them run to the ocean through the desert; this will be left to the last. Moreover, locks will be built to control the tides. De Lesseps, confident that the canal will be finished in 1889, says there will be no time in the interval to construct the locks; that they can be made later. The chief point being that shipping shall pass through the canal. See Bulletin du Canal Océanique, issued since 1879; Engineering, 1883-4; Reclus, Explor., in Tour du Monde, for a series of views; Sullivan's Problem of Interoc. Communic., Washington, 1883; Ammen's Interoc. Ship Canal, Phila., 1880; N. Y. Herald, Feb. 6, 1882; Encyclop. Brit. (Am. ed., 1885), xviii. 213.