Written by Kate Gilbert
The Fresnel Lens has been an unwavering object at the Custom House Maritime Museum
since it was installed in the late 1970’s. Many people have seen it lit at night while strolling
the boardwalk, while out in the harbor in their boat, or while visiting the museum. Many of
our visitors, and the residents of Newburyport, may well believe that the lens is in the
permanent collection of the Museum. However, through our wonderful relationship with
the US Coast Guard, the Fresnel lens has actually been on loan to us for almost 40 years.
Installed in the downstairs hallway, it lit our visitors paths for decades as a symbol of the
merchant shipping industry in Newburyport, and an homage to our very own lighthouses.
After such a wonderful extended engagement, it is now time for our beloved Fresnel Lens
to make its way back to its original home: the Pomham Rocks Lighthouse in Riverside,
Rhode Island.
Our 4th Order Fresnel Lens was originally installed in the Popham Rocks Lighthouse in 1926,
and it was used there until June 1974 when the lighthouse was decommissioned by the
United States Coast Guard. The Friends of Pomham Rocks Lighthouse is a 501(c)3 non-
profit that was established in 2004 to restore and maintain the 1871 historic landmark. We,
as a Museum, believe that this Fresnel lens would better serve the Friends of Pomham
Rocks Lighthouse as they work to ensure the historic restoration and preservation of
Pomham Rocks Lighthouse. While we have had the pleasure of being good stewards of this
object for the time that we have had with it, we feel that this lens is an integral part of their
history and it fulfills their mission clearer than our own. As a professional Museum, it
would be an unethical decision to keep it at this site purely for sentimental value (no
matter how much we will miss it!).
The Pomham Rocks Lighthouse was first lit on December 1, 1871 with a sixth order Fresnel
lens showing a fixed white light. Just over a year later, the color was changed to a fixed red
light, which it remains today. That 6 th order Lens was replaced by our beloved 4 th Order
Fresnel Lens as an upgrade in 1926. The Fresnel lens is a compact lighthouse lens
developed by French physicist Augustin-Jean Fresnel (1788–1827). Fresnel produced six
sizes of lighthouse lenses divided into four ‘orders’ based on their size and focal length,
First-Order being the largest. The lens uses prisms arranged in concentric circles, which
greatly reduced the size and weight of the lens, and were far more powerful, throwing light
much further than previous lighthouse lens designs. Although we currently broadcast a
white light through it, it always broadcasted a red light while it was placed at the Pomham
Rocks Lighthouse.
The lighthouse itself was operated by six civilian lightkeepers, before the Coast Guard took
over operations in 1956, and operated through 1974. In 1978, the property was purchased by
the Mobil Oil Corporation with the intent of preservation. In 2000, the now Exxon Mobil
Corp was approached by local citizens regarding the possibility of a partnership to restore
the lighthouse to its 1871 condition, to which they happily agreed, and even funded a large
part of it. That is when the Friends of Pomham Rocks Lighthouse was formed, and the
historic preservation began. In 2006, the lighthouse was relit after having been dark for 32
years. Exxon Mobil Corp transferred ownership of the island and its buildings by donating
them to the American Lighthouse Foundation in 2010, and since then, numerous
preservation activities have been completed. Reacquiring the Fresnel Lens would be a huge
coup for their society and would help to give real meaning to their preservation activities.
We, as the Custom House Museum, do hope that the public shares in our excitement as
this wonderful object is finally returned home.