Pomham Rocks Lighthouse Receives the Best Gift for its 150th Birthday
For a mariner, the voyage home is often long and arduous. So, too, was the journey of the soul of Pomham Rocks Lighthouse, now returned home.
A lighthouse’s Fresnel (fray-NEL) lens is sometimes referred to as its very soul. Constructed of multi-faceted glass prisms arranged in concentric circles, the lenses are both an engineering masterpiece and a priceless work of art. In1851, Congress ordered Fresnel lenses to be installed in all existing and newly constructed lighthouses. Pomham Rocks Lighthouse, built in 1871 on an island off the coast of Riverside RI, was first lit with a 6th order lens, visible for about 7 to 8 nautical miles.
Circa1926, a more powerful 4th order Fresnel lens was installed, which doubled the visibility, greatly improving the safety of shipping to the port of Providence and in upper Narragansett Bay. The lens remained in operation until 1974 when the U.S. Coast Guard decommissioned The Lighthouse. It was replaced with an external light on a metal-framework tower placed next to the building. Pomham Rocks’ Fresnel lens was sent to the Lightship Museum at Boston’s Constitution Wharf. It was later loaned by the Coast Guard to Custom House Maritime Museum in Newburyport, Mass., where it was displayed for more than four decades.
To mark the 150th anniversary of Pomham Rocks Lighthouse this year, the nearly century-old Fresnel lens is being brought back to its original home this fall. It will be disassembled in Newburyport and reassembled in its island light station in Riverside. These highly specialized procedures will be performed by a professional Coast Guard lampist, one of only six skilled artisans in the country experienced in conservation of this historic optical navigational equipment.
The Fresnel lens will be the centerpiece of the museum exhibit at Pomham Rocks Lighthouse. When Covid-19 guidelines allow, the Friends of Pomham Rocks Lighthouse will offer boat trips for the public to tour The Lighthouse and view the iconic lens. For information on upcoming events to celebrate Pomham’s jubilee year or to join Friends of Pomham Rocks Lighthouse, visit