For the past several days I’ve been lurking in the light to come up with something for the CLMOOC Make Cycle #5, which is about “Storytelling with Light.” Once in a while I like to lurk to see what others are posting and to give myself a little bit more time to present something worthwhile. How was I going to tell a story about light, tell a story using only light, or come up with something unique? Well, I had decided to learn about light before I could even begin to contemplate a story I wanted to tell.
Since I’m not really the scientific type, I recalled only a few types of light learned in my most recent chemistry class, but what I had learned there was mostly about the wavelengths of light. Then I asked myself what types of light are there that I might encounter on any given day? There are the literal kinds of light (like fluorescent light, etc.), and then there are the figurative types of light (love light, etc.). So after doing quite a bit of research on the topic of light, and learning about the different types of light, I still needed to do some kind of storytelling with light. I volunteer at a lighthouse, so what better story is there to tell than that of the strongest man made light beam installed in a lighthouse in the United States in 1841—the Fresnel (pronounced “fruh’-nell”) Lens.
The photo above is that of the Navesink Light Station, called Twin Lights and located in Highlands, NJ, looking south towards Sea Bright, NJ (with only the South Tower in view, as I was standing in the North Tower to take the photo). As a volunteer for the Twin Lights for the last 3 years, I have learned about some of the history of this lighthouse, and have visited many other lighthouses, mostly in New Jersey, around the Great Lakes region, New York, and Maine. The importance of the Twin Lights rests in its proximity to New York City. The Sandy Hook Lighthouse is the oldest remaining colonial era lighthouse (built in 1764) and still operating. It was formerly called the New York Lighthouse, since it was closest to New York City at the time it was built—and it is visible when standing in the tower of the Twin Lights Lighthouse and looking north.
As a volunteer at Twin Lights, one of the most frequently asked questions is, “Why are there two lighthouses?” Though I don’t know the official answer to that question, I surmise that it has to do with the era in which the lighthouses were built. In 1862, when the current Twin Lights replaced the crumbling 1828 Twin Lights, our nation was still not industrialized and relied heavily on goods and services from Europe. For example, even though cotton was being grown in the southern states, there were no textile mills where the cotton could be woven into fine fabrics, so it was shipped to England and eventually returned to the states. Remember that at this time there was no radar, no radio, and no depth finders, etc. for these cargo ships to use to locate New York City, which was THE place to come to in the United States. Lighthouses were the primary source of sighting land at the time, especially as ships approached at night.
Each lighthouse had its own unique light pattern, for example, the Twin Lights had one light that was fixed—shining its beam straight out and flashed at an interval of 5 seconds on and 5 seconds off—and one light that revolved with a constant beam. The Sandy Hook Lighthouse had a fixed light that also flashed, but with different intervals. The way a lighthouse is painted (the “day mark”) is also unique, and the pattern of the lights and day marks were known to the ship captains of the day, probably handed down through the generations, and was the GPS of the day. The constant revolving beam of the Twin Lights South Tower’s Fresnel Lens was so powerful that the reflection of it could be seen in the sky 70 miles from shore; the source of the light couldn’t be seen (because of the curve of the earth), but the reflection could. The strength of this light was also known to the sea captains, so if they could see a powerful light reflecting in the sky and couldn’t see the source of the light, they knew that they were approaching New York City and the Twin Lights.
There currently are several places around the world where there are twin and even triplet lighthouses next to each other, but there is no other place in the world where there are two lighthouses up on a hill and one down below at the shore line, like there is with the combination of the Twin Lights and the Sandy Hook Lighthouses. So, to answer the initial question of “Why are there two lighthouses?” the answer received is that there really are three lighthouses, which are close to each other (less than 5 miles apart), because it makes it really special—one-of-a-kind—and could easily be spotted by sailing ships.
The Fresnel Lens is no longer in the South Tower (if you look closely at the photo, you will see that the lens room is empty), but is on display in the Generator Building portion of the museum, where it revolves as it once did in the South Tower, and is available for the public to view.
A little anecdote/piece of history: The Fresnel Lens was so powerful that when it was installed in 1841 and made its 360º turn, it would keep the cows awake —all night—at the farms located behind the lighthouse and beyond. The cows wouldn’t give milk if they didn’t sleep, so the farmers wrote a letter to their congressman to ask that something be done about the light. This resulted in the back 1/3 of the lens rooms to be blacked out (also blacked out in the 1862 Twin Lights, which is visible it the above photo), so that the light didn’t shine behind the lighthouse, where it wasn’t needed.
For more information on the Twin Lights Lighthouse, visit the website or come for a visit. If you come on a Sunday afternoon, you’ll usually find me volunteering in the Museum Shop. The lighthouse is open year round: Memorial Day through Labor Day, open 7 days and beginning after Labor Day through Memorial Day, open Tuesday through Sunday.