Joseph Pennell prided himself on immortalizing the world's great industrial behemoths, but he believed his life would not be complete unless he could chronicle the greatest wonder of them all—the building of the Panama Canal. Photographs show him wandering the site in his tweeds, campstool in hand. He chanced to capture this amazing scene at quitting time, as the workers were being hauled, clinging to a chain, out of eighty-five-foot-deep Gatun Lock. "No one could imagine it—and I had only a minute to see it," Pennell wrote. He sketched such scenes on special coated transfer paper and executed the prints on lithographic stones back home in Philadelphia.