NICARAGUA AND THE ISTHMIAN ROUTES 255 



locks close together near the Pacific coast, and the uncertainty 

 of a sufficient water supply for the summit level. 



The Truando-Atrato route is a modification of the Napipi- 

 Atrato route, the project being to leave the Atrato river about 80 

 miles from its mouth and then to cut a sea-level canal through 

 a tunnel under the continental divide into the Pacific, the flow 

 of the Atrato river being diverted into the Pacific ocean. The 

 length of the cut from the Atrato to the Pacific would be 43.2 

 miles. The cost of the work has been variously estimated from 

 $135,000,000 to $156,000,000. The chief difficulties of this route 

 are the considerable tunnel excavation and the control of the 

 flood waters of the Atrato river. 



San Bias Route. — This route lies between the gulf of San Bias 

 in the Caribbean sea and the mouth of the Bayano river on the 

 Pacific. It is the narrowest part of the entire isthmus, being 

 only 30 miles from ocean to ocean. It is proposed that the level 

 of the water in this canal be that of ordinary high tide in the 

 Pacific ocean. The tides in the Caribbean sea being inconsider- 

 able, no provision need be made to accommodate them ; but on 

 the Pacific coast the tides are from 16 to 20 feet, and a lock would 

 have to be provided for maintaining the canal at any desired 

 level. At high tide the lock can be left open, while at low tide 

 there would be a considerable descent by means of the lock. 

 This route requires the construction of a tunnel seven miles 

 long, which it is proposed shall be 80 feet wide at the surface of 

 the water and 140 feet high from the canal bottom. Much dis- 

 agreement has arisen regarding the practicability and cost of the 

 proposed tunnel. No work of any such magnitude or under such 

 conditions has yet been attempted, and it is claimed that the 

 gloom of a tunnel, the constant shower of chilled water from its 

 roofs and sides, and its deoxygenated condition would rapidly 

 undermine the health of the workmen, who would be unable to 

 combat successfully the malaria and other enemies to health 

 which abound on the isthmus. The long tunnel required, with 

 the accompanying uncertainty of cost and practicability, is the 

 chief objection to the San Bias route, though unquestionably this 

 route has obtained a higher degree of public favor than any other 

 excepting the Panama and Nicaragua routes. 



Panama Route. — This route lies between Colon or Aspinwall, on 

 the coast of the Caribbean, and Panama, on the bay of Panama. 

 The existence of fairly good harbors at each end is on'e of the 

 reason- for theadvocacy of this route, and in 1851 a railroad was 



