History of Central America, Volume 3, 1801-1887 / The Works of Hubert Howe Bancroft, Volume 8

by Hubert Howe Bancroft

The canal company published a pamphlet, in which the estimates for the canal were made at New York prices, and in which the total was put down at $13,243,099. 'The prices adopted in the estimate of $31,500,000,' says Colonel Childs, 'are made up with reference to the completion of the work within six years from the time of breaking ground, and a commencement of the settlement of the country in the vicinity of the line previous to letting the contracts.'

Capacity of the Proposed Canal.—The charter of the canal company provided that the capacity of the work should be sufficiently great 'to admit vessels of all sizes.' And it is obvious that a work which will not pass freely the largest vessels can but imperfectly answer the purposes of its construction, or meet the requirements of commerce. But Colonel Childs proposed only one 17 feet deep, 50 feet wide at bottom, and 118 feet wide at top—a capacity wholly inadequate to pass the larger classes of vessels, and one which fails to meet the stipulations of the charter. The larger merchant-ships, such as are generally employed in the eastern trade, have a draught of from 20 to 25 feet, and would require, to say nothing of war vessels and large steamers, a canal of from 25 to 30 feet in depth, which would involve more than double the amount of excavation proposed, and probably treble the amount of cost, and carry it up from $31,500,000 to $100,000,000. Here is the fatal deficiency in the whole proposition of Colonel Childs.

To make the canal capable of passing vessels drawing 20 feet of water, Colonel Childs says, would increase to a very great degree the amount of the excavation on the river section, and still more the expense. 'Any considerable increase in the depth proposed (17 feet) would require under-water excavations between the lake and the Toro Rapids, a distance of 27 miles, to be almost continuous; it would very much lengthen the cuts on the other portions of the river, and the liability of these artificial channels to receive deposits of earth to such an extent as to obstruct navigation would be very much greater. On the inland portion of the canal,' continues Colonel Childs, 'a depth of 22 feet of water would, with fifty feet bottom-width, give a transverse water-section about 45 per cent greater than a depth of 17 feet, with the same bottom-width; and the expense of the inland portions would also, by reason of the greater depth of excavation, be increased in a still higher ratio.'

THE VIEWS OF COLONEL CHILDS.

Colonel Childs seems sensible of the inadequacy of a canal of the proposed dimensions, but thinks that by changes in model, etc., ships of great size could be built to pass a 17-foot canal. That is to say, the world may build ships for the canal, instead of the canal company a canal for the ships of the world! He states that most steamers draw less than 17 feet, and quotes from Murray's Treatise on Marine Engines to show that of 261 steam-vessels, principally English, 15 draw over 17 feet, 21 have 17 feet draught, and 225 less than 17 feet. But he neglects to tell us that experience and economy point to the construction of larger steamers than those now in use, and that such as would be used in the eastern trade, in the event of the construction of the canal, would be still larger than those of the Collins line, which draw over 22 feet. Besides, a canal of 17 feet is only adequate to the passage of vessels of 15 feet draught. No canal ought to be contemplated with a less depth than 25 feet, and with proportionate top and bottom width.

The Chesapeake and Delaware Canal has a depth of 10 feet.

The Welland Canal is 28 miles long, 9 feet deep, 35 feet wide at bottom, and 71 feet at top. It passes vessels of 350 tons.

The Caledonian Canal, between the eastern and western shores of Great Britain, is 59 miles in length, of which 21½ miles is inland and 37½ through lakes. It is 50 feet wide at bottom, 110 feet at top, and is 20 feet deep. It is capable of passing frigates of 32 guns, and merchant-vessels of 1,000 tons.

The canal from Amsterdam to New Dieppe, in Holland, is 50 miles long, 36 feet wide at bottom and 124 at top, and is 20 feet 9 inches deep.

In respect of navigating the canal, according to Colonel Childs' suggestions, steamers will propel themselves, and sail-vessels will be moved by tugs constructed for the purpose, except on the portion west of the lake, and between the river and port of San Juan, where the delay of the driving steamers in passing the locks would make the use of animal-power advisable. Calculating 24 minutes as the time required for a vessel to pass each lock, 60 vessels, it is calculated, could be passed in a day. The average rate of speed with which steamers might safely move in the inland portions of the canal is calculated at 2½ miles per hour, on the river portions 7 miles an hour, and on the lake, 11 miles an hour. Sailing vessels propelled by horse-power might move on the canal at the rate of two miles an hour, and on the river and lake with an average speed of 4 miles per hour. For steamers, therefore, the passage from sea to sea is estimated at 46½ hours, or about two days; for sailing vessels, 77 hours, or 3¼ days.