Fresnel lens specialist Dan Spinella installs Piney Point's new reproduction lens. Photo: St. Mary’s County Museum Division

Piney Point Lighthouse $30K Replica Lens Now on Display

Once upon a time, a 5th Order Fresnel Lens lit Piney Point Lighthouse, guiding mariners to safety on the Potomac River. That complex 1800s lens was lost to history in the years after the lighthouse was decommissioned, but a unique exact replica has just arrived to become the centerpiece of the lighthouse museum.

The intricate 5th Order Fresnel Lens cost about $30,000 to produce and comes from a Florida-based company specializing in historic full-scale reproduction Fresnel lenses. The Friends of St. Clement’s Island & Piney Point Museums led several years of fundraising to order the lens from Artworks Florida Classic Fresnel Lenses, LLC.

The complex workings of a Fresnel lens are similar to a grandfather clock. Photo: St. Mary’s County Museum Division

The St. Mary’s County Museum Division wanted to add an exciting focal point to Piney Point Museum’s recently installed exhibits, and felt the exact replica was the perfect display. A “Learn About the Lens” museum program for visitors is being developed along with exhibit panels.

Artworks Florida Classic Fresnel Lenses installed the lens in mid-February. Fresnel lenses were invented by French physicist Augustin Fresnel in the early 1800s. They use a complex system of lenses, mirrors and panels rotated by a weighted clockwork mechanism with gears and cables like a grandfather clock. That allowed the lens to rotate at specific speeds and radiate much more light in all directions than past lighting methods.

For more information about the exhibit or to visit Piney Point Lighthouse Museum, call 301-994-1471 or visit

-Meg Walburn Viviano