“Perry’s two vessels were without question not only successes, but far beyond the most sanguine hopes and expectations of friendly critics of the time. It is a remarkable fact that the _Susquehanna_ (and some others of smaller size) built after the _Mississippi_ and the _Missouri_ had proved themselves successes, were not successes. With these latter, Commodore Perry had nothing to do, as to plans, designs or construction.” No sketch of the early history of the steam navy of the United States could be justly made without honorable mention of Captain Robert F. Stockton. Nor was the paddle-wheel of the _Mississippi_ to remain the emblem upon the engineer’s shoulder-strap. The propeller screw was soon to supersede the paddle-wheel as motor of the ship and emblem of the engineer’s profession. The screw is one of the many discoveries located, by uncritical readers, in China. The French claim its invention, and have erected at Boulogne a monument to Frederick Sauvage its reputed inventor. Ericsson demonstrated its value in 1836, by towing the _Admiralty_ up the Thames at the rate of ten miles an hour; yet the British naval officers reported against its possibility of use on ships of war. Eight years afterward, the man-of-war, _Rattler_, was built as a propeller, and a successful one it was. Ericsson, after constructing the engines of the propeller steamer, _Robert F. Stockton_, was invited to Philadelphia, where he built the first screw steamer of the United States Navy, and of the world, planned as such. After the name of his native town, it was called by the Commodore, the _Princeton_.