In 22·37 miles, or 57 per cent. of the canal in excavation, the prism is large enough for vessels in transit to pass each other, and of a sectional area in excess of the maximum area in the Suez Canal; the remaining distance in which large vessels cannot conveniently pass each other is so divided that the longest is only 3·67 miles in length; with two exceptions, those short reaches of narrow canal are situated between the locks, and can be traversed by any vessel in less time than is estimated for the passage of a lock; consequently, unless a double system of locks be constructed, nothing will be gained by an enlargement of the prisms. The exceptions referred to are the rock-cuts through the eastern and western ‘divides,’ 2·58 and 3·67 miles, respectively, in length. The possible detention in the transit, due to those narrow cuts, which should not in any case exceed 45 minutes, would not justify the necessary increase of expense involved in an enlargement of the cross-section proposed. Both the bottom width and the depth of the proposed canal are larger than those of the Suez Canal. In the lake and in the largest portion of the San Juan River vessels can travel almost as fast as at sea. In some sections of the river, and possibly in the basin of the San Francisco, although the channel is at all points deep and of considerable width, the speed may be somewhat checked by reason of the curves. Estimated time of through-transit by steamer. Hrs. Mins. 38·98 miles of canal, at 5 miles an hour 7 48 8·51 miles in the San Francisco basin, at 7 miles an hour 1 14 64·54 miles in the San Juan River, at 8 miles an hour 8 4 56·50 miles in the lake, at 10 miles an hour 5 39 Time allowed for passing 7 locks, at 45 minutes each 5 15 Allow for detention in narrow cuts, &c. 2 0 ─────── Total time 30 0 The experience of the Suez Canal shows that the actual time of transit is more likely to fall under than to exceed the above estimate.[209] The traffic of the canal is limited by the time required to pass a lock, and on the basis of 45 minutes (above estimated), and allowing but one vessel to each lockage, the number of vessels that can pass the canal in one day will be 32, or in one year 11,680,[210] which, at the average net tonnage of vessels passing the Suez Canal, will give an annual traffic of 20,440,000 tons. This is on the basis that the navigation will not be stopped during the night.