Lighthouses had different techniques for rotating the light, most being too slow, making the light less visible. Augustin Fresnel proposed a mercury flotation system in 1825. Despite some lenses weighing over 6,000 lbs. the design reduced friction, increased rotation, and ultimately saved lives.

Lens Rotation by Thomas Tag Introduction There are three major types of lenses used in lighthouse towers – fixed, flashing, and a combination of fixed and flashing. Flashing lights are the most effective and powerful. The first lens created by Augustin Fresnel was a flashing lens. The flashing lens rotates and has a number of …

Lighthouses had different techniques for rotating the light, most being too slow, making the light less visible. Augustin Fresnel proposed a mercury flotation system in 1825. Despite some lenses weighing over 6,000 lbs. the design reduced friction, increased rotation, and ultimately saved lives. Read More »