“Altogether between nineteen and twenty million cubic yards will have been brought into the canal prism by slides before the completion of the work. About 5,915,000 cubic yards of this extra material was taken out during the year ending July, 1912, or more than thirty-three per cent. of the total excavation for that year. Less than 4,000,000 cubic yards of slides remain to be accounted for.”
“Have these slides proved the impossibility of a sea-level canal here?” I asked.
“Absolutely,” he replied.
“Will new slides continue to develop after the water has been turned into the cut?”
“Two things will tend to minimize that tendency,” he replied. “First, there will be no more shaking of the ground by blasting; second, the forty-five feet of water in the channel will exert a pressure on the banks of thirty-one tons per running foot of canal. Any earth brought into the cut then could be easily taken out by dredges.
“The last steam-shovel should be taken out of the cut, and all remaining rock broken up by blasting in the dry, by July 1, 1913. Then the dike at Bas Obispo will be blown up, and the water from Gatun Lake will flow into the cut and through Pedro Miguel Lock into Miraflores Lake. The dredge Corozal, now working at sea-level at the Pacific end of the canal, will then be brought up through the Miraflores and Pedro Miguel locks, and put to work in the cut.”
Prominent among the few ornaments of Colonel Goethals’s bare, barrack-like office is a framed photograph of the Corozal, the largest ladder-dredge in the world. Each bucket of her endless chain lifts two cubic yards at a time. She was built in Renfrew, Scotland, in 1911, by a firm that thirty years ago made several smaller dredges for the De Lesseps Company. After rusting for a quarter of a century in tropical tidal-swamps, most of these, floated and cleaned, are still doing good work. Their honest craftsmanship impelled the purchase of the Corozal. Virtually like all the floating equipment at the Pacific end of the canal, she was brought round South America under her own steam. Her name is that of the first railroad station out of Panama City, and, literally translated, means “Merry-go-round.”
“There will always remain a certain amount of dredging to be done in the two entrances, at Balboa and in Limon Bay,” the colonel continued.
“And to keep Gatun Lake clear of silt and wreckage brought down by the Chagres River?” I asked.
“No,” he replied. “There will be several miles of dead water at the upper end of the lake above Bas Obispo, where it will settle before reaching the channel.”