The life of the brilliant marine designer and naval architect, John Ericsson (1803 - 1889), who designed and built the Civil War ironclad Monitor which defeated the Confederate Merrimac. Ericsson's propeller is still the main form of marine propulsion 150 years later. It replaced the inefficient and vulnerable steam-driven oars and paddle wheels. Ericsson also developed a calorific engine designed to use solar energy.