The hydroelectric station uses water from Gatun Lake for driving three turbogenerators of 2,000-kilowatt capacity each, which supply electricity for the operation of the lock and spillway machinery, the terminal shops and adjacent facilities, and for the lighting of the locks and the canal villages and fortifications. Transmission over the Zone is effected through four substations and a connecting high voltage transmission line which follows the main line of the Panama Railroad.

Submarines Used in Defending the Panama Canal.

The vessels here shown are used in defense of the Pacific side of the canal. They appear as anchored in the new concrete docks at Colon, preparatory to their passage through the canal, after having made the longest sea voyage then on record for submarines.

Copyright by Underwood & Underwood, N. Y.

Copyright by the International News Service. THROUGH THE PANAMA CaNAL.

The U. S. battleship "Ohio" in the east chamber of the Pedro Miguel Locks. On the left is seen the electric locomotive used in drawing vessels through.

Ladder Dredge, Panama Canal.

Suction Dredge, Panama Canal The upper view shows a ladder dredge, which operates by means of buckets on a continuous chain, dipping the contents of the buckets into the scow which lies alongside. The lower view shows a suction dredge, which operates on soft mud or sands, pumping the discharge through the pipe seen at the left of the illustration. The pipe may be carried to any desired point and used for filling..

Copyright, C. II. Graves Co. GaTUN LOCKS.

A. Sea-level section of canal, seven miles long, from Atlantic Ocean to Gatun Locks, whereby a series of three locks vessels are raised to Gatun Lake, eighty-five feet above sea level. B. Small area of land dredged away as soon as Gatun Locks were completed. C. Electric towing motor, four of which tow each vessel entirely through the locks. They run on cog rail along the lock walls. D. Lock gate under construction. E. Floor of first lock from Atlantic side. Note holes in floor for admitting the water. F. Lock for vessels coming from Pacific side. G. Base on which concrete posts were erected for electric lights. A row of lights on all sides of the locks making operation at night as safe as day. H. Incline from locks of different levels up and down which the towing motors run on cog rails.

Gaillard Cut Looking South from Bend in East Bank near Gamboa.

The train and shovel are standing on the bottom of the cut. The water in the drainage canal is about ten feet below the bottom of the canal, or at elevation+30.

A Cylindrical Valve Machine, Motor and Limit Switch.

This machine is one of many which are used to regulate the flow of water to the locks. All valves are controlled from a central operating station on each of the three sets of locks. The limit switch automatically shuts off the power and stops the motor when the valve is entirely open or shut.

Cucaracha Slide Attacked by a Fleet of Dredges.

This great slide was the source of much trouble to the engineers. At one time it entirely blocked the canal at the narrow point shown in this photograph, but the seven dredges of the ladder, suction and dipper type, made short work of cutting the 150-foot channel shown here, and then proceeded with the work of entirely clearing the cut. The view looks north from the slide past Gold and Contractor's Hills.

Copyright by Underwood & Underwood, N. Y.

Steam Shovel Buried Under Fall of Rock.

The Great Gaillard Cut.

At this point the canal is cut through what is practically a mountain range. The material excavated consisted largely of rock and formed one of the hugest engineering problems in the world's history. The cut is nine miles long, 300 feet wide, 272 feet greatest depth and required the excavation of 100,000,000 cubic yards of material.

Gatun Lake, impounded by Gatun Dam, has an area of 164 square miles when its surface is at the normal elevation of eighty-five feet above sea level, and is the largest artificially-formed lake in the world. The area of the water-shed tributary to the lake is 1,320 square miles. During the rainy season, from April to the latter part of December, the run-off from this basin exceeds considerably the consumption of water, and the surplus is discharged through the spillway of Gatun Dam. Toward the end of the rainy season the surface of the lake is raised to about eighty-seven feet above sea level, in order to afford a surplus or reserve supply to keep the channel full to operating depth during the dry season, in part of which the consumption and evaporation are in excess of the supply. It is calculated that when this level has been attained at the beginning of the dry season the reserve is sufficient to assure a surface elevation of at least seventy-nine feet at the end of the dry season in spite of the consumption at the hydroelectric station, and allowing forty-one passages of vessels through the locks each day with the use of the full length of the chambers, or fifty-eight lockages a day when the shorter sections of the chambers are used and cross filling is employed, which would usually be the case. This is a greater number of lockages than can be made in one day.

Steam Shovel Loading Rock.

These great machines, which are able to dig out and load several tons of material at each operation, made the rapid progress in digging the canal possible.