508 



INTEROCEANIO CANAL. 



might be modified by deepening the cut in the 

 Pass of Tarifa, thus reducing the number of 

 locks to 120, by carrying the canal nearly to 

 Minatitlan before uniting it with the Coatza- 

 coalcos, and by directing it straight across the 

 lagoons to the sea instead of carrying it ob- 

 liquely by the way of certain torrents to the 

 Bay of Salina Cruz. The country was declared 

 to be more healthy, and the facility and rapid- 

 ity with which the canal could be constructed 

 greater, than by way of Nicaragua or Darien. 

 The objections to this route were not based 

 solely on the number of locks which would be 

 required and the length of time which the 

 passage would take, but also on the frequency 

 of volcanic disturbances of the soil, which 

 would possibly necessitate extensive repairs at 

 times in the locks, stopping for the time being 

 all traffic. 



Nicaragua, the second contraction in the 

 long neck which connects the two Americas, 

 was the site specially favored by the American 

 engineers present at the Congress and by the 

 American public for the prospective canal. 

 This isthmus seems destined by nature for an 

 interoceanic canal notwithstanding that its 

 minimum breadth, 208 kilometres, exceeds 

 that of Tehuantepec or Darien owing to the 

 presence of the Lake of Nicaragua, lying in the 

 center of a valley which extends across the 

 isthmus from northwest to southeast, with the 

 port of Greytown or San Juan del Norte at 

 one end, and that of Fonseca, on the Pacific, at 

 the other. The lake is 176 kilometres (107 

 .miles) long and 56 kilometres (34 miles) broad. 

 The elevation of the lake at mean high water 

 is 32 - 6 metres above the sea-level; its varia- 

 tions of level are 1J to 2 metres. The lake is 

 40 metres deep in the middle, and has a depth 

 of 8 metres close to its western shore ; but in 

 its eastern portion the alluvial deposits of the 

 river Frio have created shoals for a distance 

 of 10 kilometres. The outlet of the lake is not 

 far from the mouth of the Frio by the river 

 San Juan, whose length in a straight line is 

 125 kilometres. This river down to the de- 

 louchure of the San Carlos winds in a very tor- 

 tuous course between two mountain-chains, and 

 is broken in five places by rapids. The San 

 Carlos and the Serapiqui affluents wash down 

 large quantities of alluvium. Its valley broad- 

 ens below the mouth of the San Carlos. Its 

 lower course is through a low plain ; and its 

 mouth is a delta with two principal branch- 

 es, the San Juan proper, which discharges at 

 Greytown, and the Rio Colorado, which emp- 

 ties farther south and carries off the greater 

 part of its waters. It was not proposed to 

 carry the canal up the valley in the northwest 

 by way of Lake Managua to Fonseca, but to 

 find a passage to the Pacific from the western 

 shore through the mountains, a distance of 

 only 16 kilometres (10 miles), by passes whose 

 elevation hardly exceeds that of the yoke of 

 Managua. Five different passages proposed 

 vary from 23 to 38 kilometres in length, and 



the elevation of their highest ground from 46 

 to 300 metres above the sea. The character of 

 the region west of the lake is essentially vol- 

 canic, the surface rocks of trap and basalt being 

 15 metres thick in places. The calcareous 

 rocks on which they rest are exposed in vari- 

 ous places. Conglomerates which are disin- 

 tegrated by the action of the air are also com- 

 mon. In the hollows and places of low eleva- 

 tion there is an alluvial deposit 12 or 15 metres 

 in depth. The mountains which incase the 

 San Juan River are likewise the cones of ex- 

 tinct craters, and their sides are covered with 

 feldspar which glitters with iron pyrites. The 

 harbor at Greytown was still good in 1860, 

 but ia now nearly blockaded by a bar of sand, 

 and is only accessible through a long and wind- 

 ing channel. On the Pacific side the different 

 routes terminate in harbors such as the Bay 

 of Salinas, the port of San Juan del Sur, and 

 the Bay of Nacascoba, which are or could easi- 

 ly be made accessible for vessels of the deep- 

 est draught; the Bay of Brito, at the mouth 

 of the Rio Grande, is a little too open, but 

 could be made into a large and quiet haven by 

 the construction of a jetty. The climate of 

 the elevated portions of the Nicaragua route is 

 extremely healthy ; but in the lowlands on the 

 Atlantic side, where there is a fall of rain al- 

 most every day in the year, fevers are common 

 and easily contracted ; yet, owing to the fre- 

 quent breezes from the northwest, which carry 

 off the miasma, they are generally of a mild 

 type. The configuration of the Isthmus of 

 Nicaragua, like that of the Tehuantepec route, 

 forbids the idea of a canal without locks. The 

 plans of Lull and Menocal are the result of 

 extensive surveys of this region in 1872 and 

 1873. The Lake of Nicaragua forms the natu- 

 ral reservoir of the canal. The surface of the 

 lake at mean high water is 32 '6 metres above 

 the sea-level. To descend to the two oceans, 

 20 locks would be constructed, 10 on each side. 

 It would follow the bed of the San Juan, on 

 the Atlantic slope, as far as the mouth of the 

 San Carlos, a distance of 102 kilometres, and 

 would then be carried on the left bank of the 

 river a distance of 70 kilometres, to terminate 

 at Greytown. Lateral canals, dams, and locks 

 would have to be constructed at the rapids 

 the lock at the Castillo rapids with a lift of 5'7 

 metres, others at the rapids of Balas and Ma- 

 chuca with lifts of 5*8 and 6*8 metres, a fourth 

 at the head of the artificial canal with a dam 

 extending across the river. The canal to be 

 carried across the plain from the mouth of the 

 San Carlos to Greytown would be partly ex- 

 cavated and partly banked up, the work being 

 so calculated, and the six locks so disposed, 

 that the excavated soil would be just sufficient 

 for the embankments, and that the deepest cut 

 would not be over 3 metres above the surface 

 of the water in the canal. The descent to the 

 Pacific from the western side of the lake offers 

 no excessive difficulties. The engineers chose 

 the passage by the Rivas Pass, although its 



