This rare view from inside the lens reveals the cavernous scale, hundreds of prisms and one of the lighting apparatuses that powered it all. Barnegat Light Historical Society & Museum.

By Reilly Platten Sharp

History records that storied Barnegat Lighthouse is the second tallest in New Jersey after Absecon. And depending on the source, it ranks as the 10th tallest lighthouse in the United States. But therein lies a documentary inconsistency. The tower at Barnegat Inlet is listed by various organizations, groups, societies, books, documents, and websites spanning its 164-year history as 150, 157, 163, 164, 169, 172, 178 and 189 feet tall. As well, some explain that these figures are the height of the “tower” while others claim it is the height “above sea level.” Even so, which one is which and of them all which is accurate? That a well-documented and photographed historic landmark dating back before the Civil War could have such a basic fact about it so unclear is a testament to the way life, history, and the proprietary language of engineering can cause history to drift into the fog of oversimplification and myth.

The questions remain, though — why has the height been so varied for so long and how tall is Barnegat Lighthouse anyway?

Plans for “Old Barney” began as early as 1852 while the Bureau of Lighthouses was bombarded with cries of righteous indignation from international boat captains frequenting Barnegat Inlet and its far-reaching outer sand bars as they guided their cargoes and passengers into the gateway to the New World at New York harbor. Such cries forced the hand of the government nearly twenty years earlier to establish a network of navigational aids to stem the tide of wrecked vessels on the most dangerous shoals and at the mouths of the narrowest inlets and rivers along every coast of the growing United States. If America was to grow as an international trading power and generations of men, women, and children from across the globe were going to populate the vast North American continent after being borne across the vast oceans aboard ships, then wrecking upon the shores so close to the promises offered by the land of opportunity had to be minimized as much as possible. Engineers could not stop the hand of God from rendering ships asunder in apocalyptic hurricanes or violent nor’easters, but they could make it so that a dark, rainy night was not all it took to condemn dreams and souls to watery graves at the very doorstep of the Western world. So it was that a lighthouse was operational on Barnegat Inlet starting in late 1834. But the first tower’s criminally inferior construction and the lack of forethought to integrating the vast coastal network together combined to make the constellation of lights meant to guard American shores little more than fireflies attempting to glow during a rainy pitch-black night. The first Barnegat lighthouse was so weakly powered that scores of mariners over the years alleged it was the tower itself that drew them off course like a siren’s song, reportedly mistaking its low dim beacon for that of a pilot boat meeting it at the outer reaches of New York harbor for escort into port.

When a replacement light at Barnegat Inlet was at long last authorized, after a series of scandalous wrecks around it in the years preceding the 1857 start of construction, Army Corps of Engineers Lt. George Meade was put in charge of not just Barnegat but numerous of the giants by the sea marking the approaches to New York. Meade requested of Congress in 1855 that a tower “to be 150 feet high” should be erected at Barnegat and use the revolutionary French Fresnel lenses that were proven so effective in European lighthouses by that time. Indeed, it was the lenses that formed a basis for new categorization and measurements by which American lighthouses would be graded.

Unlike most buildings and structures, lighthouses are unique because their purpose also determines how they are measured and designed. A lighthouse is simply a tower, of stone, brick, steel and even wood in some cases, which holds up a lighted navigational aid of some kind, whether a simple fire in ancient times or an electrified LED beacon still active in many around the world today.

When Lt. Gen. Meade was outlining his plans to Congress for Barnegat’s new light, he spoke in engineering terms to break down the components of it. In writing that he would order construction of a tower “150 feet high” if granted the funding, in lighthouse terms that meant the pedestal of material upon which the light itself would be held up.

In this case the brick tower at Barnegat would stand 150 feet above the ground, atop which would be the most powerful navigational aid in the world of the 1850s — a two-ton first-order Fresnel lens standing over 10 feet tall and comprised of 1,008 custom hand-cut glass prisms.

The lighthouse looms over the old keeper’s house as erosion threatens in the summer of 1919. National Archives.

But the engineering specifications for the lighthouse do not end with “tower height.” The craftsmanship and scientific marvels that are Fresnel lenses work thanks to carefully calculated placement. Tower height is not something that can be set merely based on material availability or budgetary concerns. In order to do its job to protect marine traffic, the intensity of the lens’s power, from the giant first-order to the small but still effective sixth-order, must be made-to-order based on how far its light must reach and how brightly it must shine. When that is figured out, the tower height becomes critical in establishing the single most important measurement for any Fresnel-powered lighthouse — the focal plane.

The focal plane, or height of a lighthouse is the distance from sea level — not the ground at the base of the tower — to the focal point of the lens, otherwise known as its bull’s-eye where the light is the brightest and creates the beam that strikes far out to sea to be visible to mariners if they come within its reach.

At Barnegat Lighthouse, the immense and powerful first-order Fresnel lens had twenty-four vertical panels with thick circular bull’s-eye prisms at the middle. This precise design and the choice of twenty-four panels was carefully arranged to make Barnegat unique among all other American lighthouses. Along with a type of fuel to cause a certain color flame and the lens’s placement in a rotating clockwork mechanism and the speed at which the rotation was set, no other lighthouse would shine like “Old Barney” would for sixty-eight years. A bright white flash every ten seconds nearly twenty miles out to sea alerted every mariner that they were passing Barnegat Inlet, and only Barnegat Inlet, and the storied shoals that marked her mouth which had claimed so many vessels and lives across 400 years of seafaring history.

Figures vary for the Barnegat Lighthouse focal plane, along with the other measures given for the tower’s various parts. What are the accurate numbers, though? To find out, State Park officials, construction personnel overseeing the 2022 – 23 restoration work on the lighthouse, the Friends of Barnegat Lighthouse and this writer worked together to find those answers. And the results were surprising.

Thanks to brave folks who could conquer their fear of heights if they had it, the traditional measure of any structure was precisely documented to be 168 feet. That is the height from the ground to the very top of the roof, including any caps, vents, or antennae.

With that figure, Meade’s original plan for a 150-foot tower could be reasonably confirmed as the height from the ground to the top of the brickwork at the base of the metal and glass enclosure where the lens was mounted for so many years of service, otherwise known as a lantern room harkening back to the days when it was lit with flame and fueled by lighthouse keepers during long, stormy nights without respite.

Construction manager Jeff Rapp and Park official Diane Gormley marveling at the rarely touched top of Barnegat lighthouse after measuring its height in summer 2022. Jeff Rapp photo.

That establishes the overall height and the tower height. But what about the focal plane? For that, USGIS topographical surveys were turned to. Barnegat Lighthouse stands 16 feet above the water below its rocky base and beside its deep stone and brick foundations that were so threatened the tower was in danger of toppling several terrible times during its day. So “Old Barney” is 184 feet above sea level, with a corresponding tower height of 166 feet. With a 10-foot lens atop the tower in the lantern room from floor to ceiling, which puts the bull’s-eye at 5 feet for a focal plane of 171 feet.

What is surprising but perhaps fitting is with the exception of the 150-foot tower height projected by Meade, neither the now-measured 168-foot overall height nor the adjusted 184 feet overall, 166-foot tower and 171-foot focal heights above sea level were among those frequently cited for heights of Barnegat Lighthouse. It is a credit, however, to 19th century engineering that the Army Corps had it right and French artisans were able to hand-craft high-tech lighting thousands of miles away to protect captains, crew and thousands upon thousands of passengers encountering one treacherous New Jersey inlet. So it is that Meade’s tower stands tall 164 years on, now known to be 168 feet tall. All of these discoveries, however, raise new questions. Absecon is celebrated as the tallest lighthouse in New Jersey. But is it really? How was it measured? How have the scores of other lighthouses been quantified? And who will find that out? — Reilly Platten Sharp

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