Wednesday, September 19, 2012

Fortress on the Bluff: Ingenuity and Innovation at the Twin Lights of Navesink

Fortress on the Bluff: Ingenuity and Innovation at the Twin Lights of Navesink
Written by NJ Historian


Two hundred feet above sea level on the New Jersey coast is a peculiar bluff with what looks like a fortress resting atop. This “fortress” has been protecting and guiding ships into New York Harbor for 150 years. The Twin Lights Lighthouse has been home to a number of firsts in lighthouse history and wireless innovation because of their unique and strategic location. The lighthouse was one of America’s most technologically connected and continues to connect curious visitors with the past 150 years later.


A lighthouse was built on the bluff as early as 1828. The original Twin Lights were designed by Connecticut architect Charles H. Smith. Smith was instructed to “well and faithfully construct, erect, build, and in every respect completely finish two lighthouses and a dwelling house...on the Highlands of Navesink.” The towers he designed were approximately 40 feet tall.  The original keepers’ quarters was constructed of wood, with two rubble stone towers and beacons 320 feet apart. The first light keeper was Joseph Doty of Somerville and was paid $40.00 a month in 1828. The United States Lighthouse Board decided on two lighthouses in the Highlands in order for mariners to distinguish them from the Sandy Hook Lighthouse, five miles to the north. In the early 1800s, the U.S. Lighthouse Board philosophy stated that lighthouses should have a fixed (non-rotating) light, thus necessitating the two lights in the Highlands in order to avoid confusion with Sandy Hook’s fixed light. Ultimately it was decided that one tower was to have a fixed light and the other a rotating light. The U.S. Lighthouse Board constructed seven dual or twin lights, and one triple light, following the same philosophy. However, the high operating expense of these multiple units eventually convinced the board to consider other alternatives. Finally, the U.S. Lighthouse Board determined it would be more cost effective and practical to give each lighthouse its own distinguishing light pattern.

1861 lithograph of the original north tower and construction of the new tower. Source: Twin Lights Archive.
In 1841, a pair of Fresnel lenses was installed at the Twin Lights. The lenses were the first ones brought to the United States. Three years earlier, Commodore Matthew Perry was dispatched by Congress to study European lighthouses. During his time in Europe he learned about the work of French physicist Augustine Fresnel. The Fresnel lens was far superior to any navigational lighting apparatus being used in the United States at that time. The lens used concentric rings of glass prisms to concentrate ambient light into a narrow beam. The center of the lens was shaped like a magnifying glass, so the concentrated beam was even more powerful. Tests showed that while an open flame lost nearly 97% of its light, and a flame with reflectors behind it still lost 83% of its light, the Fresnel lens was able to capture all but 17% of its light. Because of its amazing efficiency, a Fresnel lens could easily shine its light twenty or more miles to the horizon. Fresnel produced six sizes of lighthouse lenses, divided into orders based on their size and focal length. In modern use, these are classified as first through sixth order. The Twin Lights’ lenses resembled huge bee hives of glass surrounding a light. The lenses were capable of producing 6,000,000 candlepower. The south tower of the Twin Lights received a first-order lens and the north tower received a second-order lens.


Original second-order lens from the north tower in the 1902 generator building.
By 1852, Congress received a report on the nation’s lighthouses that was highly critical. The Twin Lights, which at that time were in desperate need of repair were ironically singled out as the best in the nation. The report said the towers, “are in a dilapidated condition, the consequence of original bad materials and workmanship, and it has been represented that there is apprehension they are not capable of standing much longer.” Because of the report’s findings, the U.S. Lighthouse Board was created. One of their first acts was ordering a rebuilding of the Navesink Light Station.


The Twin Lights painted by Granville Perkins, 1872. Source: Twin Lights Archive.
In 1862, a new Twin Lights Lighthouse was constructed at a cost of $74,000. It is the only lighthouse in the United States built in a fortress style. It was designed by architect Joseph Lederle of Staten Island and was constructed of brownstone, an unusual feature as brownstone was chiefly used in residential building. The new towers would be 250 feet apart and connected by a keeper’s dwelling. The north tower was constructed in the shape of an octagon and the south tower was square, giving them a unique appearance.

Schematics of the north tower. Source: National Archive.
In 1898, the original south tower lens was replaced with one of the largest bivalve lenses ever produced. In that same year the south tower was electrified with an electric arc lamp, the first time an American lighthouse was to be powered by electricity and have its own generating plant. It was the only on-shore lighthouse in the United States with its own generator. The electric arc light produced 25,000,000 candlepower and was the most powerful light installed in a lighthouse in the United States. Its light was visible for twenty-two miles at sea, though there were reports of it having been seen as far away as 70 miles when the light was reflected off a low lying cloud bank. That same year the light in the north tower was discontinued.

The south tower was automated in 1949 but was discontinued in 1952 as the importance of lighthouses diminished. In 1962, the site was turned over to the State of New Jersey, which installed a sixth order lens and reactivated the north tower as a private aid to navigation. The north tower remains active to this day.


The Twin Lights are also associated with a number of other important events:

First Official Reading of the Pledge of Allegiance
In 1893 the Twin Lights were selected as the location for the first official reading of the Pledge of Allegiance as America’s national oath of loyalty. This event coincided with the opening of the Colombian Exposition in Chicago and featured a grand naval flotilla off the coast of Sandy Hook. The Pledge of Allegiance event was held around a new addition to the Twin Lights, a 135-foot Liberty Pole. During the 1890s and early 1900s, the Liberty Pole was the first “piece of America” seen by millions of immigrants as their ships travelled toward Ellis Island.

Wireless Telegraph
Messages from the first practical demonstration of wireless telegraph were sent from the site on September 30, 1899 by famous Italian inventor Guglielmo Marconi. Marconi had been invited to America by Gordon Bennett, Jr., the owner of the New York Herald to report on the America’s Cup sailboat race using his wireless technology. He transmitted messages from a boat offshore, which were then sent to the newspaper for publication. Marconi maintained a wireless station at the Twin Lights for a few years before deciding that other locations on the United States’ coastline would provide better reception for his equipment. Marconi’s experiments established the commercial viability of wireless communication and provided the foundation for the technology that led to the wireless devices which are commonplace today.


Marconi's radio antenna. Source: Twin Lights Archive.
Radar
Starting in the late 1920s, a series of top-secret experiments took place at Fort Monmouth. In 1935, the U.S. military set up at the Twin Lights to test what the newspapers were calling a "mystery ray." Eventually the “mystery” was solved and it is now called radar. The radar experiments held at the Twin Lights helped the Allies win World War II and led directly to the innovations that today guide airplanes and even missiles!

Over the past 184 years, the Twin Lights site has been host to a number of firsts and technological achievements in the United States. From its first keeper, Joseph Doty, to the last keeper, Murphy Rockett, these men and their families watched experimentation, innovation, and progress occur right before their eyes, 200 feet above sea level in their fortress with a view of the ocean.


Additional photos of my trip to the Twin Lights on Pinterest.
Audio
Twin Lights Podcast (right click and choose "save target/link as" to save to your hard drive)

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