To give a mere list of the work with which Ericsson was occupied during the years from 1827 to 1839, when he removed to the United States, would be no small task, and reference to the more important only can be here made. Compressed air for transmitting power, forced draft for boilers by means of centrifugal blowers, steam boilers of new and improved types, the surface condenser for marine engines, the location of the engines of a ship for war purposes below the water line, the steam fire-engine, the design and construction of the "Novelty" (a locomotive for the Rainhill contest in 1829, when Stephenson's "Rocket" was awarded the prize, though Ericsson, heavily handicapped in time and by lack of a track on which to adjust and perfect the "Novelty," achieved a result apparently in many ways superior to Stephenson's with the "Rocket"), various designs for rotary engines, an apparatus for making salt from brine, further experimental work with various forms of heat, or so-called "caloric" engines, and the final development, in 1833, of a type from which great results were for a time expected, superheated steam and engines for its use, a deep-sea-sounding apparatus embodying the same principle as that later developed by Lord Kelvin in the well-known apparatus of the present day, a machine for cutting files automatically, various types of steam-engines, and finally his work in connection with the introduction of the screw-propeller as a means of propulsion for steam vessels. These are some of the important lines of work on which Ericsson was engaged during the twelve years of his life in London. In connection with some he was undoubtedly a pioneer, and deserves credit as an original inventor; in connection with others, his work was that of improvement or adaptation; but in all his influence was profound, and the legacy which we have received from this period of engineering progress is due in no small degree to Ericsson, and to his work in London during these years. At a later point we shall refer in some further detail to these questions, but desire for the moment, rather, to gain a broad and comprehensive view of his life as a whole.