We come in due time to the upper entrance of the Pedro Miguel lock. Here the precipitous sides of the Canal have vanished, and the walls of the lock have in fact to be built up above the adjacent land. This is the end of the Central Division--the end of the Culebra Cut. The 8.8 miles we have left behind us have been the scene, perhaps, of the most wonderful exercise of human ingenuity, skill and determination ever manifested in any equal space in the world--and I won’t even except Wall Street, where ingenuity and skill in cutting things down are matter of daily observation. But nowhere else has man locked with nature in so desperate a combat. More spectacular engineering is perhaps to be seen on some of the railroads through our own Sierras or on the trans-Andean lines. Such dams as the Roosevelt or the Shoshone of our irrigation service are more impressive than the squat, immovable ridge at Gatun. But the engineers who planned the campaign against the Cordilleras at Culebra had to meet and overcome more novel obstacles, had to wrestle with a problem more appalling in magnitude than any that ever confronted men of their profession in any other land or time. [Illustration: DEEP SEA-DREDGE AT BALBOA] As no link in a chain is of less importance than any other link, so the Pacific Division of the Panama Canal is of equal importance with the other two. It has not, however, equally spectacular features. Its locks at Pedro Miguel and at Miraflores are merely replicas of the Gatun locks with different drops, and separated into one step of two parallel locks at the former point, and two steps, with four locks in pairs at Miraflores. Between the two locks is an artificial lake about 54²⁄₃ feet above sea level and about a mile and a half long. The lake is artificial, supplied partly by small rivers that flow into it and partly by the water that comes down from the operation of the locks above. In fact it was created largely for the purpose of taking care of this water, though it also served to reduce somewhat the amount of dry excavation on the Canal. One advantage which both the Gatun and Miraflores lakes have for the sailor, that does not at first occur to the landsman, is that being filled with fresh water, as also is the main body of the Canal, they will cleanse the bottoms of the ships passing through of barnacles and other marine growths. This is a notable benefit to ships engaged in tropical trade, for in those latitudes their bottoms become befouled in a way that seriously interferes with their steaming capacity. [Illustration: PROPORTIONS OF THE LOCKS A six story building would stand in the lock-chamber. Size of conduits indicated by small sketches of wagon and locomotive.]