Designed for Seafarer Safety

Designed for Seafarer Safety. . , From top to bottom, Heceta Head Lighthouse , is built to guide from afar. , The light’s height was most likely chosen to maximize its range while minimizing the chances it would be hidden by fog. Unlike most Fresnel lenses of the day, which were made in France, the lens at Heceta Head was made in England, and is the largest English lens of its type in the U.S. Heceta’s light is the brightest light on the Oregon Coast. , Lighthouse Lingo , Fresnel lens: parabolic type lens invented by French physicist Augustin Fresnel, classified by size into six orders (first order being the largest). This lens is a first order. , Kerosene: fuel used in the lamp to produce light. , Lens: curved piece of glass used to bring together or spread light. , Bull’s-eye: convex lens used to concentrate (refract) light. , Characteristic: individual flashing pattern and/or color of light. , Clockworks: series of gears, chains, and counterweights used to rotate the lens (similar to a grandfather clock). , Revolving light: rotating beam of light that produces a flash or characteristic. , Gallery: railed platform outside the lantern room. , Lantern room: area with glass panels surrounding the lamp and lens at the top of the tower. , How Does a Fresnel Lens Work? , Light shining through a flat plate of glass would disperse in all directions. But light shining through a Fresnel lens hits the angled cuts on the glass and is bent until it all faces outward in the same direction. , The Fresnel lens is a technology invented in 1822. The eight-sided lens continuously rotates around the light. One of the eight bull’s-eyes in the lens passes by the mariner’s eye every 10 seconds, creating a characteristic flash pattern used to identify the source and triangulate position. This flash can be seen 21 miles out to sea before it is obstructed by the curvature of the earth.