INTEROOEANIO CANAL. 



elevation is 28 metres higher than tho Pass of 

 yol. Tbo route follows the course of 

 :': ilol Medio to tho Rio Grande. The 

 c ui.il leavos the lake near the inouth of the 

 ' 1 Medio, receiving the waters of this 

 suiiill stream at the distance from the lake of 

 8 kilometres. After crossing tho Rivas Pass, 

 ivos another creek, the Chicolata, beyond 

 which tho first lock is located, 17 kilometres 

 from the lake, joins tho valley of the Rio 

 Grande at tho place where it broadens, and 

 terminates at a point near the mouth of that 

 river. The total length of the canal would be 

 290 kilometres, the distance requiring artificial 

 canalization 100 kilometres. The principal ex- 

 cavations to be made in the western section 

 would be the excavation of a channel into the 

 lake for 360 metres by blasting, and a cutting 

 through the Rivas Pass 41 metres high above 

 the surface of the water in its deepest spot, 

 and averaging 8 metres for the whole distance 

 to the first locks. In the eastern section, be- 

 sides the inland canal, partly excavated and 

 partly diked in, and the dams and locks to pro- 

 duce slackwater navigation in the Rio San 

 Juan, the rocks in the rapids of Toro will have 

 to be cleared away, and the bed of the river 

 to be deepened by an average of 1^ metre 

 down to those rapids, and also for 1 kilo- 

 metre above the lock at Balas ; the deposits of 

 tho Frio River will also have to be dredged out 

 to a mean depth of 2 metres below the pres- 

 ent bottom of the lake for 10 kilometres. The 

 sands would have to be removed to make a 

 harbor at Grey town, and a breakwater must 

 be constructed at Brito. The proposed depth 

 of tho canal is a uniform one of 8 metres 

 throughout its course ; in the diked-in portions 

 of the canal, and generally in the excavations 

 in earth, the breadth at bottom is to be 22 me- 

 tres, at the water-level 46 metres, at 3 metres 

 above 55 metres, the banks having an incline 

 of over 45 degrees, the increase iu breadth 

 being to the increase in elevation as 3 to 2. 

 In the deep cuts in earth the same relative 

 profile is preserved, but the breadth is lessened 

 to 15'2 metres at the bottom and 37 metres at 

 the water-line. In the rocky excavations tho 

 incline of the banks is increased to over 45 

 degrees, and the breadth at the bottom is di- 

 minished to 18*2 metres, that at tho water-line 

 being 27'4 and at 3 metres above 82'3 metres. 

 The harbor at Greytown would be preserved 

 from the deposits which are washed down by 

 the San Juan, by damming that river and turn- 

 ing its course into the Colorado. A second 

 jetty at Brito would shut off the harbor in like 

 manner from the Rio Grande and protect it 

 on that side. Besides the 10 locks on the Pa- 

 cific side, a sea-lock would be constructed at 

 Port Brito. Tho total excavations necessary 

 would amount to 48,000,000 cubic metres of 

 excavation in the canal, blasting on the west 

 aide of the lake and in the Toro rapids, and 

 the rest of it dredging. The cost of the differ- 

 ent portions of the work was estimated as 



follows: For the western division, from the 

 mouth of the Rio del Medio to the Brito har- 

 bor, $21,080,777; for subaqueous excavations 

 in the lake, $715,658 ; for the eastern division, 

 from Fort San Joan to Greytown, embracing 

 the establishment of 63 miles of slackwater 

 navigation in the San Carlos and the construc- 

 tion of 45 miles of canal, $25,020,914; for 

 works in the harbor of Brito, $2,833,789 ; for 

 harbor-works at Greytown, $2,822,630. This 

 makes a total cost of $52,577,718, which by 

 adding 25 per cent, for errors and contingen- 

 cies is augmented to $65,722,147. 



A second project for a lock-canal across Nic- 

 aragua was presented by M. Blanchet, mate- 

 rially different from the plan of tho American 

 engineers. Its principal feature was a scheme 

 for preserving the level of the lake in the canal 

 for the greater part of the length of the San 

 Juan River, as far as the San Francisco, an 

 affluent which joins the San Joan from the 

 north between the mouths of the San Carlos 

 and Sarapiqui. As in this project also it is 

 necessary to shut out from the canal the waters 

 of the Rio San Carlos, heavily charged with 

 detritus, the valley of the San Jnan, whose 

 whole breadth is occupied by the canal down 

 to this point, is dammed, and the canal is car- 

 ried into a channel which runs close to the 

 heights on the left bank, the necessary exca- 

 vations furnishing the material for embank- 

 ments on the southern side of the canal. Be- 

 sides these cuttings, the only other labors 

 necessary from the lake to the San Francisco 

 will be the blasting of the rocks in the rapids 

 of Castillo and Toro to a depth of H and 6 

 metres respectively, which operations will ena- 

 ble the current to carry away the accumula- 

 tions above Toro. A long wall in the lake will 

 protect the channel from new deposits of the 

 Frio. Two or three locks near the Rio San 

 Francisco bring the canal down to the second 

 level, which extends down as far as the San 

 Juanillo branch of the delta. Here, as above, 

 it is led along the cliffs of the left bank, and 

 shut off from the transverse valleys on the 

 right by embankments thrown across their 

 mouths. The canal is lowered to tho sea-level 

 by means of four or five locks, placed at the 

 head of the San Juanillo, and carried across 

 to Greytown by excavations in the low flat. 

 On the Pacific side a channel is to be made 

 through the valley of the Lajas, by blasting 

 1,200 metres into the lake, and by a cut in the 

 Guyscoyol Pass, into the valley of the Rio 

 Grande, which is to be made into a lake, like 

 the San Juan Valley, by a dam at La Flor; 

 from which point the canal would descend to 

 the sea at Brito by 7 looks. The dam at La 

 Flor must be 400 metres long, and must sup- 

 port 20 metres of water. The locks are to be 

 200 metres each in length and 24 metres broad, 

 able to accommodate two large ships at a time ; 

 their average lift would be 4J metres. In or- 

 der to avoid delay from a pressure of traffic 

 or during repairs, there should be a complete 



