Propeller

A propeller is a type of propulsor with a rotating hub and radiating blades set at a pitch to form a helical spiral that exerts thrust on water or air when rotated, driving ships or aircraft forward. The principle traces to ancient Archimedes screws used for pumping water, but the modern marine screw propeller emerged when the English engineer Francis Pettit Smith and the Swedish-American engineer John Ericsson independently patented workable designs in 1835 and 1836; the screw-driven steamship SS Archimedes, launched in 1838, was the first vessel built around the technology. The Wright brothers later adapted the same helical-blade principle to aircraft, twisting their propeller blades like an airfoil rather than a simple screw, a refinement that became standard for powered flight.