The _Desague_ was constructed between 1607 and 1650, and with its dykes and two canals leading from the upper lakes, is stated to have cost 31,000,000 of livres, or 1,291,770_l._ According to Humboldt, however, 25,000,000 of livres “were expended because they never had the courage to follow the same plan, and because they kept hesitating for two centuries between the Indian system of dykes and that of canals—between the subterraneous gallery and the open cut through the mountain.” Humboldt adds that “they neglected to finish the cut of Nochistongo, while they were disputing about the project of a canal of Tezaico, which was never executed.” The meaning of Humboldt’s reference to the cost of this undertaking is rather obscure. One writer has pointed out that if he means that the necessary cost of the work was only 6,000,000 livres, or 250,000_l._, there falls to be deducted from this amount the cost of two other canals—those of Zampango and San Christobal, begun in 1796 and 1798—amounting to 41,670_l._ more.[125] This, however, is not at all likely to be Humboldt’s meaning, since he elsewhere speaks of the _Desague_ as “undoubtedly one of the most gigantic operations ever executed by man,” and looks upon it with “a species of admiration, particularly when we consider the nature of the ground, and the enormous breadth, depth, and length of the aperture.” The magnitude of the undertaking may be appreciated by the fact, mentioned also by Humboldt, that if the _Desague_ were filled with water to the depth of 10 metres (32 feet), the largest vessels of war could pass through the range of mountains which bound the plain of Mexico to the north-east. Of the other rivers in South and Central America none call for any special description. Few of them are navigable for any distance, being—like the Chagres river, which traverses the Isthmus of Panama, or the San Juan river, that is to be utilised for the Nicaraguan canal—too rapid, tortuous and subject to floods, to be convenient for purposes of navigation. In course of time, however, as wealth and population increases, we may naturally look for the artificial improvement of such waterways with a view to their adaptation for purposes of commerce, as in the European rivers already referred to. FOOTNOTES: [123] Van Nostrand’s ‘Magazine,’ vol. xxiv. p. 66. [124] Further details as to the navigation and traffic on the Magdalena may be found in the U.S. Consular Reports, No. 47, 1884, pp. 334-348. [125] Pitman’s succinct view and analysis of authentic information extant in original works, on the practicability of joining the Atlantic and Pacific Oceans by a ship canal across the Isthmus of America. London, 1825. CHAPTER XVIII. CHINESE WATERWAYS. “But if, with bays and dams, they strive to force His channel to a new or narrow course, No longer then within his banks he dwells, First to a torrent, then a deluge swells.” —_Denham._