The 1859 Cape May Lighthouse: built to withstand the tests of time and sand
LOWER TOWNSHIP — The Cape May Lighthouse has majestically stood at the southern tip of New Jersey since 1859. To this day, it faithfully marks the northern entrance to the Delaware Bay, a significant waterway for 400 years.
Earlier lighthouses nationwide were proving to be inadequate — they were too small, too dim, and often hastily and poorly built, mostly because of the lack of funds. By the 1850s, after many seacoast disasters and complaints from ship captains, the federal government realized the necessity for tall, enduring structures that could emit powerful beacons and resounding fog signals.
New demanding construction standards and policies for seacoast lights (as opposed to smaller light stations specific to rivers, inlets, etc.) were put into effect by the government:
1. All new American lighthouses were to be equipped with a Fresnel (Fray-nel) lens. These incredible crystal lenses designed to magnify and project a light beam were a revolutionary new invention in 1822 by French scientist Augustin Fresnel.
2. Seacoast lights must at least be 150 feet high. This height will allow the beam to be seen (technically called an “acquisition”) about 20 statute miles away on a clear night, considered to be an adequate distance for a mariner to determine his position.
3. Towers must be able to withstand five times hurricane-force winds. (375 mph!)
4. Towers must last at least 100 years.
5. The United States Lighthouse Service was eventually created to employ qualified, trained, uniformed individuals who would be responsible for the care, maintenance, and performance of their assigned light stations. Earlier light keepers had been hired through a political spoils system.
The 1850s were the dawn of a new day in American lighthouse history.
In 1857 the U.S. Army Corps of Engineers arrived in Cape May with a $40,000 commission to build a state-of-the-art lighthouse on “the point.” Captain William F. Raynolds and a small staff supervised civilian mechanics and laborers during construction. Raynolds followed the plans and diagrams of fellow Army Engineer and lighthouse architect, Captain George Meade. We know him, of course later, as General Meade of President Lincoln’s Army of the Potomac.
This beautifully realized structure consists of a 145-foot brick tower topped with a 12.5-foot metal and glass lantern. As nearly as be can determined, 500,000 bricks were used. The tower is supported by a footpad of stone blocks that pyramid out to 12 feet underground. Under the footpad is a grillage of creosoted timbers for further stability. The Lighthouse was completed in October of 1859, with its whale oil lamp officially first lit on Halloween at sundown.
The tower tapers elegantly and to exaction: its diameter is 27 feet at the base, and 13.5 feet at the top. Meade’s design called for two separate brick walls: an outer, conical, tapering one, and an interior, cylindrical brick column, with air space between the two. The walls join near the top. A cast iron stairway spirals up the inner wall — no taper inside, recall, so the steps are all the same width throughout. There are 199 of these iron steps (perforated for weight considerations and aeration) to the watch room immediately below the lantern, with six landings symmetrically positioned (at each turn-and-a-quarter) along the way.
At five of the landings there is a window and a brick “barrel-vaulted” arch that connects the two walls (each landing, naturally, will be shallower than the one below as the outer wall tapers in). These connecting arches give the tower walls an unbelievable strength; additionally, they evenly distribute the weight of the walls down the side. At each arch are ventilating openings, or “weep holes” that allow air to circulate between the walls to prevent moisture build-up which would attack the brick and mortar. Small access doors to these air chambers are located at the base of the staircase for cleaning and inspection purposes.
To quote from John Bailey’s authoritative book, “The Sentinel of the Jersey Cape: The Story of the Cape May Lighthouse”:
“The most plausible theory on the construction of the tower holds that the builders constructed the spiral stairway as they laid the brickwork. (We surmise this because they pinned the leaves of the stairway into the masonry.) They actually worked on the inner wall from the stairway itself carrying bricks and mortar up these same steps.
They worked on the outer wall using scaffolding erected outside the tower. One thing is certain: the builders were master masons. The alternating mortar lines, inside and outside, follow a perfectly straight sight line up from the base to the watch room. Each of the courses lays impeccably level and true. A reinforcing stratum of bricks laid crosswise, so that you can see only the ends of the bricks, separates every five courses.
The bricks themselves have curves that follow the curvature of the walls inside and out, Present day master masons who visit the lighthouse marvel at the beautiful arches on the ground floor, the detailing throughout, the smooth corner mitres, and the workmen’s obvious pride in craftsmanship.”
Visitors commonly ask, “Why not just build a solid tower?” — in other words, why go to all the trouble to solve the engineering problems of double walls, air chambers, connecting arches, etc.? The answer is that the Cape May Lighthouse sits on sand, sometimes wet sand — there is no convenient bedrock out at “the point.” It was determined that a solid brick or stone tower of that size would not have been stable there.
The Cape May Lighthouse still stands perfectly true, 160 years and counting.
(Author Rich Chiemingo, known fondly as “Keeper Rich” has been with Cape May MAC for 20 years, having served as Lighthouse Manager, Lighthouse Keeper Interpreter, World War II Lookout Tower Observer, Museum Educator and, with his helicon, John Philip Sousa Interpreter).