The “divide” cut from the basin of the San Francisco to the upper lock, 14,200 feet in length, and with an average depth of 149 feet, is admitted to be a serious work; but with the neighbouring streams offering water at a high head for removing the surface earth by hydraulic mining, with a large plant of power drills worked by compressed air from the same source, and the use of modern explosives to loosen the rock, with a large proportion of the excavated rock to be used in the construction of the locks and the dam, and in pitching the slopes of the canal, a still larger quantity utilised in the construction of the harbour at Greytown, and convenient dumping-grounds for the remainder, the engineers claim that the work can be accomplished. The following description of the proposed locks is taken from the report of Mr. Menocal, one of the engineers:— “The locks proposed have a uniform length of 650 feet between the gates, and at least a width of 65 feet between the gate abutments. Locks Nos. 1, 2, 4, 5, and 6 have lifts of 26, 27, 26·4, 29·7, and 29·7 feet respectively. No. 3 has a lift of 53 feet, and No. 7, being a combination tide and lift lock, its lift will vary between 24·2 and 33·18 feet, depending on the state of the tide. It is believed that Nos. 1 and 7 will rest on firm, heavy soil, but timber and concrete foundations have been provided for in the estimates. Nos. 2 and 4 are estimated to rest on solid rock, and as for Nos. 5 and 6, the borings taken in 1873 show that stiff clay, compact sand and gravel will be met with. No. 3 is proposed to be cut out of the solid rock in the eastern slope of the ‘divide,’ by which the maximum strength will be secured with the least expense, concrete will be used only to the extent required to fill cavities, to give the proper dimensions to the various parts, and to give a surface to the blasted rock. The other locks it is proposed to build of concrete, and all of them, No. 3 included, will have a heavy timber lining in the chambers and bays, extending from the top of the walls to 15 feet below the low-water level.