Turn of the century photographs of dirty, hot, cramped machine spaces filled with boilers, engines, gratings and bulkheads begin to tell the story of the state of steam power just after the birth of the propeller. Oil squirt cans, dancing connecting rods, and sweating coal passers and firemen characterized the engine rooms of the late 1800s when paddle wheels were gradually being replaced with the screw. Pioneers of screw propulsion experimented with an assortment of propeller designs before commercial application of the concept began. The first screw-driven vessel in the U.S. Navy was the Princeton, built in 1843 by John Erickson. Even though the prop had many advantages over the paddle wheel…