VI.-ONE OF THE LARGE 105-TON, 5-CUBIC- IN CULEBRA CUT This great shovel scoops up, swings around, and loads upon dirt-cars 5 cubic yards of earth or rock each time the dipper is operated. The record day's work for this shovel was 4,823 cubic yards of rock, which amounted to 8,395 tons. It would have required 3,500 two-horse wagons to remove it. of the great concrete wall of the locks, for the entire canal is constructed upon such a huge scale. The walls are as thick as a city street is wide, resting on a firm foundation 100 feet or more beneath the surface of the bottom of the lock. XII. GATUN SPILLWAY The spillway is a great crescent-shaped concrete dam 808 feet long. It holds back the water of Gatun Lake during the dry season and regulates the overflow during the MIRAFLORES LOCK TO BALBOA, THE rainy season. The crest of the dam is 16 VII. THE GREAT SEA-LEVEL DITCH FROM PACIFIC ENTRANCE Standing on the centre wall of the Miraflores lock an excellent view is obtained of the work of digging the great sea-level ditch from the lock to Balboa, the Pacific entrance to the canal. This and cleaning up Culebra Cut is practically all that remains to complete the canal from the Atlantic to the Pacific. VIII. GATUN LOCKS, LOOKING FROM THE TOP The upper gates of the Gatun locks are closed in the picture, holding back the water of the lake. The concrete columns for electric-light clusters, to which Mr. Bishop alludes in his article, are shown in the central strip. A ship in its progress through these locks is lifted three times, the combined height being 85 feet. The Gatun locks, as well as those at Pedro Miguel and the single lock at Miraflores, are in pairs parallel in arrangement, one side for the use of Pacificgoing vessels, the opposite for Atlanticbound boats. Each lock chamber is 1,000 feet long and 110 feet wide, and is constructed of concrete. IX.-A LOCK CHAMBER ON THE PANAMA A lock chamber is a great concrete tub, 1,000 feet long, 110 feet wide, 85 feet deep, with ends of steel. The largest vessel in the world could safely dock in any of these locks. X. THE GREAT GATES TO PEDRO MIGUEL Like the other gates at Gatun and Miraflores, those of the Pedro Miguel locks are each 65 feet wide and 7 feet thick. A comprehensive idea of this construction is gained here, for only one side of the gate has the steel plates in place, the "honey-comb" construction of the gate being plainly visible. XI. -THE GREAT CONCRETE WALLS OF THE LOCKS AT PEDRO MIGUEL It is impossible to conceive the immensity feet below the normal level of the lake. On top of the dam are 13 concrete piers, between which are mounted regulating-gates, operated by machinery. By raising or closing them the overflow from the lake is controlled. In this picture the water is shown coming out of sluiceways at the bottom of the dam which are now closed forever. |