| Designation | Panamá. | Cale- donian. |
Albany. | Tehuan- tepec. |
| Length of canal. | 47 1/2 miles | 25 miles | 12 1/2 miles | 122 miles |
| Breadth of canal at water level. | 148 ft. | 122 ft. | 120 ft. | 162 ft. |
| Breadth of canal at trench bottom. | 66 ft. | 50 ft. | 50 ft. | 60 ft. |
| Depth of water in canal. | 23 ft. | 20 ft. | 2 ft. | 22 ft. |
| Lock-length between mitre-sills. | 210 ft. | 172 ft. | 115 to 300 ft. | 170 to 320 ft. |
| Lock-breadth. | 47 ft. | 40 ft. | 31 ft. | 42 ft. |
| Lock-depth. | 20 (?) ft. | 21 ft. | ||
| Estimated trade per day. | 5,000 tons. | 10,000 tons. | 20,000 tons. | |
| Estimated supply for lockage, in cubic feet, per second. | 25,148 | 98.11 | 146.94 | |
| Estimated evaporation, gate, and leakage losses, cubic feet, per second. | 0.462 | 42.33 | 22.31 | |
| Estimated filtration, cubic feet, per second. | 62,224 | 225.22 | 1,618 | |
| Total supply, estimated in cubic feet. | 87,864 | 225.22 | 1,618.00 |
It will be well to say, before proceeding to the description of the canal-route, that the main efforts of the expedition were dedicated to its immediate object, viz., to determine the practicability of the canal. Considerable time was spent in summit explorations, and in testing the feasibility of projects previously proposed. Disappointment met us everywhere; and when at last the feeder route and its water supply were discovered, the season was so far advanced that it was impossible to extend our level lines to the Atlantic side, and locate the north branch of the canal. However, the ground has been thoroughly explored, the work previously performed for railroad and other purposes, and the profile and plans obtained from the studies of Barnard, Sidell, Orbegozo, and others, coupled with our own observations, enable me to assert with confidence that below the confluence of the Malatengo there is no obstacle whatever in the way of the canal. The broad Coatzacoalcos Valley has room enough, and is flat for a long distance on either side of its thalweg.
The soil at Tarifa is impermeable, and the feeder will deliver its waters directly upon the plains.
A crescent-shaped lake will be formed, which, owing to the nature of the ground, will retain its waters at all points, except at the Tarifa River. At this point, where the soil drains naturally to the Atlantic, the north summit-gate will be excavated.
The Pacific summit-gate will be twenty-two feet lower than the lowest point of the Tarifa Pass. The houses now at Tarifa will form a peninsula, where storehouses, repair-shops, etc., will be built.
From Tarifa the first level will start northward.
From barometric observations behind the Campanario Hill, as well as on account of the grade of the Tarifa River, it appears that there will be required nine locks between the summit and the point of confluence of Chichihua and Tarifa rivers, or one lock per mile.
From this point to Mal-paso, below Rio Chico, the bed of the Chichihua has a small slope, which necessarily widens the distance between the locks. Then the canal will run along the valley of the Coatzacoalcos.
Twenty-one miles above Rio Chico, the Coatzacoalcos falls only three hundred and sixty-three feet in more than one hundred and forty miles of
