Until the 1820s, flames reflecting off a mirrored surface fired lighthouse beacons around the world. Around 1815, French civil engineer Augustin Fresnel designed a system to use prisms to refract light and focus a powerful beam. The United States resisted using the new system for years, until it proved to be cost- effective. The first of four Fresnel lenses was installed at Cape Hatteras in 1854. Fresnel lenses were used at Hatteras until 1935, when the lighthouse closed.