NAVY OF THE UNITED STATES. 



525 



structed within the limit of an expenditure 

 more moderate than could have been expected, 

 when compared with the immensity of the un- 

 dertaking, and the great benefits that cannot 

 fail, upon its completion, to accrue to commer- 

 cial interests. 



Briefly stated, the route selected by Com- 

 mander Selfridge includes 100 miles of river- 

 navigation of the Atrato. which has been care- 

 fully sounded, and found to be fully capable of 

 being navigated by the largest class of ocean- 

 steamers. Between Atrato and the Pacific, a 

 canal or artificial cut is made but 28 miles in 

 length. The canal, for 22 miles of this dis- 

 tance, passes through a plain, with a gradual 

 rise of 90 feet. There will then remain six 

 miles to fhe Pacific, of which there are a mod- 

 erate open cut and three miles of tunneling. 

 It is estimated that the work will cost between 

 $50,000,000 and $60,000,000, and that it can 

 be completed within ten years. A careful sur- 

 vey and soundings of the Atrato resulted in 

 the fact that, though capable of navigation for 

 steamboats, even in its lowest stage, to Qui- 

 buto, the head of ship-navigation was reached 

 but a short distance above the line selected for 

 the canal. Surveys of the interior settled the 

 fact that it would not be profitable to explore 

 South of the Napipi ; not only because the 

 westerly trend of the coast made the area that 

 would have to be cut broader in extent, but 

 also that it was traversed by numerous streams, 

 forming the water-shed of mountainous ridges 

 that would have to be cut transversely. More- 

 over, the Cordilleras, which present a marked 

 depression near the head-waters of the Napipi, 

 increase rapidly in altitude toward the south. 



The Nicaragua expedition, in charge of Com- 

 mander E. P. Lull, sailed from the United States 

 in December, 1872, and returned in July, 1873, 

 after proving the existence of a practicable 

 route for an interoceanic ship-canal, having 

 Lake Nicaragua at its summit-level. It is pro- 

 posed to connect the lake with the Pacific by 

 a canal 16.33 miles long, beginning at the 

 month of the Rio del Medio, and terminating 

 at Brito. The first seven and a half miles will 

 require an excavation averaging 54 feet in 

 depth, and will be the most expensive part of 

 the whole work. For the rest of the disfance, 

 the profile is lower than the proposed level of 

 the surface of the water; embankments will 

 be constructed with the materials excavated. 

 Ten locks, and one tide-lock, will be required, 

 between the lake and the sea. There will be 

 66 miles of lake-navigation. 



Slack-water navigation in the San Juan, from 

 its head to the mouth of the San Carlos, is con- 

 sidered perfectly feasible ; and it is proposed 

 to improve the river by four dams, one each at 

 Castillo Rapids, Balas Rapids, Machnca Rapids, 

 and at the mouth of the San Carlos, at all of 

 which places excellent locations for dams 

 exist. A short section of canal with one lock 

 will he required to get around each of the up- 

 per three dams. From just above the fourth 



dam to Greytown an independent canal will 

 be required, 41.90 miles in length, of which 

 36 miles will require an excavation less than 

 the prism of the canal ; the remaining four 

 miles are made up of short reaches, where the 

 line cuts through hills. Seven locks, besides 

 those abreast the dams, will be required, and 

 should be located in the hills in order to take 

 advantage of the natural rock-foundation. 

 Some improvement will be required in places 

 in the river-bed, for which the amount has 

 been computed, and the cost estimated. 



The total length of the proposed canal is 

 61.74 miles, of which 47.37 miles are in ex- 

 cavation and embankment. The average depth 

 of excavation throughout is. but nine feet 

 above the prism of the canal. No tunnel is 

 required. The harbor of Greytown has been 

 partially destroyed by a silt which comes from 

 the San Carlos, and others of the lower tribu- 

 taries of the San Juan, and the branch of the 

 river leading to Greytown hns become so much 

 filled up that it is now, at the lowest stage of 

 the water, but 324 feet wide and six inches 

 deep at the fork. It is proposed to shut off 

 this branch entirely, and send all the silt- 

 bearing water through the Colorado mouth, 

 which empties into the sea 1& miles from 

 Greytown, and to admit to the harbor only 

 the water of the canal, which, being drawn 

 from the main river above the mouth of the 

 San Carlos, will be perfectly clean. The harbor 

 then once cleared out will leave nothing to 

 deteriorate it again. A short breakwater will 

 be required to protect the entrance from the 

 surf, also one at Brito, both of which are in- 

 cluded in the estimate for the work. Careful 

 gauges at the lowest stage show that Lake 

 Nicaragua will supply thirty-eight times the 

 maximum possible demand of water. The 

 climate is considered perfectly healthy for 

 temperate people who adopt the simplest 

 sanitary precautions. Part proof of this is 

 that not a man has been lost in either of the 

 expeditions lately operating in the country, 

 though constantly subjected to severe labor 

 and exposure. 



Much interest was manifested during the 

 year in relation to the Arctic Expedition of the 

 Polaris, in consequence of the important results 

 that were made public. It will be remem- 

 bered that the Polaris, a topsail schooner of 

 over 400 tons, under command of Captain Hall, 

 left the United States in June, 1871, on an ex- 

 pedition toward the north-pole. On the 18th 

 of August of that year, the vessel left Uper- 

 navik, Greenland, after which no tidings 

 were received until the 9th of May, 1873, 

 when the United States Government was in- 

 formed by telegraph from St. John's, New- 

 foundland, that nineteen persons, late of the 

 Polaris had been rescued from the floating ice 

 in Baffin's Bay, by the British sealing-steamer 

 Tigress, and that they had safely landed at 

 that port. The United States steamer Frolic 

 having been dispatched for these persons, re- 



