« PreviousContinue »
line than a natural one. The idea of a Rear-Admiral J. G. Walker, President of bank is of water limited by dry land with the Commission, I am informed of them some elements of permanency about it. in a letter dated July 10, 1899, from which Even during the brief period when the
I quote: line is uncovered, the idea of it is sugges- In reply I am cabling you to-day, as tive far more of mud and aquatic growths follows: Alexander, Greytown, Six;' than of dry land and forest growths. the six meaning, as per your letter, 106.0
“ To my mind, the natural, simple and as mean high level of lake. This elevaobvious idea of the bank of a lake, in this tion of 106.0 is, to the best of our knowlclimate, is presented only by the line of edge (Mr. Davis, our hydrographer), the mean high water. Here we would first mean high water for a number of find permanent dry ground every day of years. an average year. Here an observer, dur- The highest level of the lake in 1898 ing every annual round of ordinary sea- was 106.7, last of November. The elevasons, would see the water advance to his tion of our bench mark on inshore end of very feet and then recede, as if some boiler at San Carlos is 109.37... power had drawn the line and said to the "* A complete copy of this letter will be waters, ‘hitherto shalt thou come but no handed you, and also blue-prints of the further.' Here the struggle between for- maps made by the Commission of the est growths and aquatic vegetation be- lower end of the lake, which may faciligins to change the landscape. Here lines tate your work.' of drift, the flotsam and jetsam of the As this Commission is the highest exwaves naturally suggest the limits of the isting authority, I adopt its finding, and 'bed of the lake.'
announce my award as follows: “Without doubt, then, I conclude that "The shore line of Lake Nicaragua, mean-high-water mark determines the at the level of 106.0 feet, by the bench shore of the lake; and it now remains to marks of the United States Nicaragua designate that level, and how it shall be Canal Commission, shall be taken as the found.
bank of said lake referred to in the treaty “ Several surveys of the proposed Nica- of 1858.” raguan Canal route, beside that of Com- The location of the line around the mander Lull above quoted, have been southern margin of the lake was the most made within the last fifty years. Each difficult part of the whole survey. The found a certain mean high level of the country here is a vast morass, densely lake, and it might seem a simple solution covered with tropical vegetation, even the to take an average of them all. But, as sluggish streams being mostly choked each adopted its own bench-mark on the with aquatic plants. The high water line ocean, and ran its own line of levels to was defined as 106 feet, while the level the lake, I have no means of bringing their of the lake at the time of the survey was figures to a common standard. It seems
about 102. It became necessary, therebest, therefore, to adopt the figures of that fore, to determine an elevation four feet one which is at once the latest and most higher, which was usually several miles thorough, which has enjoyed the benefit from the water's edge. of all of the investigations of all of its By means of levelling, it was ascerpredecessors, and whose bench-marks on tained that the swamps had a mean slope the lake are known and can be referred to. toward the lakes of about one foot per That is the survey, still in progress, under mile, and this was made the basis of most the direction of the United States Canal of the agreements.
A few points on Commission. Its results have not yet streams were located, the area of Nicabeen made public, but, by the courtesy of ragua's two-mile zone was calculated, and
the boundary was defined by long tangents, including the proper area.
On reaching the Sapoa River a monument was erected, and a broken line to Salinas Bay was run, the boundary of the bay itself was surveyed, and the island was located.
The last important point decided by General Alexander was perhaps the knottiest of all. It was the definition of the centre of Salinas Bay, and the decision was both just and ingenious. The remarks of the Arbiter are as follows:
“ The Bay of Salinas was carefully surveyed and mapped by officers of the United States Navy in 1885, and a map of the same is published in the United States Naval Hydrographic office, No. 1025. I have adopted this map, with the consent of both commissions, as correctly representing the outline of the Bay. In shape it is a curved pocket, starting east and bending southward, about five miles long, and about one-half of that in average width. Its outline a little resembles the rounded handle or butt of a pistol, with some irregular projections and indentations.
“ It is desired to find the mathematical centre of this figure, closed by the straight line joining the headlands of the Bay.
“ The mathematical centre of an irregular figure is the mid-position of its area. All mechanical centres, such as the centre of gravity or of equilibrium, etc., in which the action of any force is concerned, must be excluded from consideration.
“ This will readily appear if we consider for a moment the case of a bay in the shape of a crescent. The centre of gravity of its figure would not fall upon the water of the bay at all, but upon the promontory of land embraced by the water. This, of course, could not be considered as the centre of the bay.
"Neither is any general mathematical process applicable, such as that of the method of Least Squares. This method will find the centres of any group of random spots, but were they disposed in cres
Map Showing the Boundary Between Nicaragua and Costa Rica.
cent form, the centre would be, not among When at that point, a line drawn them, but within the convex space which across the bow of the supposed vessel, they partially surround.
perpendicular to her course, would have Other methods must therefore be de- one-half of the waters of the Bay in front vised for finding the mid-position of ir- of it and one-half behind it. regular and restricted areas, and many “Having carefully located the point in might be suggested, more or less appli- this manner, I have determined from the cable to different figures. But it will be scale of the map, its distance from the sufficient here to indicate only the method summit point of the small island in the which I have adopted as best suited to the Bay, whose latitude and longitude are figure in hand, possessing, as this does, given upon the map as follows: something of a curved or crescent shape.
Latitude, 11° 03' 10" “I have supposed a vessel to enter the
Longitude, 85° 43' 38" Bay from the ocean, at a point midway between its headlands, and to sail a course “It proves to be 37 seconds to the as nearly as possible equidistant between northward and 14 seconds to the eastthe opposite shores, on the right and left, ward of this point. until it has penetrated to the remotest “I therefore fix the position of the cenpoint of the Bay.
tre of Salinas Bay to be: “This course, being carefully plotted
Latitude, II° 03' 47'' North. upon the map, although curved, may be taken as the long axis of the Bay.
Longitude, 85° 43' 24" West. “At right angles to it, at different "Toward this point the boundary line points, I have drawn straight lines reach- must run, from its meeting with the Sapoa ing across the Bay from shore to shore, River, unless the two Commissions can and, by use of a planimeter, I have de- agree upon a line with natural landtermined the position of such a line which marks." will exactly divide the whole area of the All the Arbiter's decisions were amiBay into equal parts. This line may be cably received by both Republics, the taken as the corresponding short axis of questions in dispute are settled, and the the Bay, and its intersection with the long boundary marked with sufficient accuaxis will be the centre of the Bay.
racy for many years to come.
THE NICARAGUA CANAL
the continental divide, forty-four feet
The canal as proposed will have a mean
of Lake Nicaragua, secured by means of good harbor at Greytown, the eastan immense masonry dam which will ex- ern terminus of the canal, with thirty tend the level of the lake fifty miles down feet of water at the anchorage and the San Juan. This stage consists of im- about the same depth in the entrance. proved river and lake channels. Third, The entrance to this harbor where it then a period of descent from the lake level to existed, has been obliterated and the harthe Pacific through the continental divide. bor itself is now a lagoon almost entirely This stage, seventeen miles, must also be enclosed, of restricted area, with only excavated.
about half the depth of water in it that The salient engineering problems con- formerly existed. Vessels for Greytown nected with the Nicaragua Canal project are now compelled to anchor in the offing as outlined by the Commission are as fol- and discharge their cargoes on lighters lows:
which are taken into the lagoon across a First. The construction of harbors at bar having a depth of less than six feet of the termini of the canal.
water. As the prevailing trade winds are Travelling in Nicaragua. strong and blow almost directly on this entrance will be the same. The sand part of the canal, the construction of a movement on the western coast, however, harbor at this terminus becomes necessary is slight as compared with that in the in the early stages of the work as well as vicinity of Greytown. The prevailing for use after the canal is completed. winds on this side are off-shore, and de
It is proposed to construct, by excava- structive storms seldom visit this part of tion, a harbor of sufficient area to accom- the coast. The cost of maintenance of the modate vessels using the canal. The en- harbor on the west side will therefore be trance would have a minimum depth of less than that of the one on the east side thirty-five feet and a bottom width of at Greytown. five hundred feet, guarded by two jetties For a part of the distance between springing from the shore line near Har- Greytown and the Florida Lagoon the bour Head. These jetties are to be built canal line passes over swampy sections, of loose stone to a height of six feet above where the material is too soft to support mean high tide, the hearting to be com- the embankments necessary to keep out posed of small and the outer portion of the floods of the San Juan, and to mainlarge stone, not easily moved by the tain the canal level itself. Protecting emwaves. It is not expected, however, that bankments are therefore to be constructed the construction of the jetties will alone over these sections. These embankments form the entrance. Dredging will also are to be located as far as practicable on be necessary and its maintenance may re- the firm land composing the neighboring quire an extension of the jetties or dredg- hills. In places, however, they cross ing or both.
ground which is soft to a considerable The western terminus of the canal will depth. Waterways are provided on the be near Brito. Here, as at Greytown, embankment lines to dispose of flood there is no harbor, and an artificial one water in the protected areas. must be constructed. The same general At two places near the Boca San Carlos engineering principles will guide in its dam site heavy cutting is encountered, the construction. The width and depth of the maximum depth for short distances being