Lighthouses

Hi Puzzlers,

Recently while channel surfing I caught the tail end of a television program on lighthouses. Just a quick glimpse of one of these majestic beauties got me to stop clicking and lay down the remote, something that rarely happens! Usually I can’t find anything to watch and I have 799 channels to choose from. This leaves me endlessly roaming, channel to channel, in a zombie like state before frustration sets in and I turn off the television. But not this time, I was completely mesmerized! Childlike curiosity took over my brain and I began diligently researching the history of lighthouses on my computer. Here is a quick review of what I found.

A lighthouse has two primary functions. First they give sailors a fixed point of reference to help them navigate day and night when offshore hazards cannot be seen. Secondly, they guide ships into harbors or anchorages. Today lighthouses also serve as symbolic monuments of civilizations efforts to reduce the hazards of seafaring. Just one look at these magnificent structures makes me stop and admire them with all their grandeur. How about you?

The first recorded lighthouse was built in 290 B.C. on the island of Pharos, by the Roman Empire. Records indicate the lighthouse used fire at night and a sun-reflecting mirror during the day to protect and guide ships around the Mediterranean. The Pharos lighthouse measured approximately 384 feet tall and stood for about 1,500 years, before succumbing to a series of earthquakes in 1326 A.D. Prior to the 1600’s lighthouses were referred to as Pharos.

America’s first official lighthouse is the Boston Light. It was built on Little Brewster Island in Boston Harbor in 1715. Prior to its construction colonist used small fires on hilltops or placed lanterns in the windows of houses overlooking harbors. The Boston Light was the first site to use a foghorn. The foghorn was a great-gun cannon, which was installed in 1719. It would be fired to warn sailors of pending dangers when visibility was low. In 1776 the original lighthouse was destroyed by the British, however, it was rebuilt in 1783 and is still operational today. “Although the Boston Light is considered the nation’s oldest lighthouse, the tower itself is only the second oldest. The oldest tower in the United States is the Sandy Hook Light at the entrance to New York Harbor, built in 1764.”

In the early years most lighthouses were lit by wood fires which required enormous amounts of wood. Coal became popular for burning during the early 1500s; it burned brighter and slower than wood, but required more attention to keep it burning bright. Candles and reflectors were also popular during this time as they produced a steadier flame and less soot and ash.
The next step in improving the visibility of lights was the oil burning lamps. These lamps used several flat, solid and round wicks. Also available was the Spider Lamp. It had a single oil reserve and used multiple wicks. A Frenchman named Ami Argand invented a lamp that used a hollow, circular wick in 1781. It allowed air to flow in on both sides of the wick, which enhanced the brightness of the flame. A large (18- to 20-inch) parabolic reflector was commonly attached to the center of this lamp to increase the lamps visibility.

In 1822, the Fresnel lens was created by Augustin Fresnel. This much thinner lens captured and focused larger fractions of light then did the reflectors, resulting in a brighter light that could be seen for longer distances. One Frensel lens could do the work of thirty Argand lamps.
The electrification of lighthouses began in the 1920s and 1930s. Once a lighthouse was electrified it could be equipped with a timer switch. Because electricity burns cleaner than oil it also eliminated the need for daily lens cleaning and maintenance. This made the need for light-keepers obsolete.

The lighthouse story does not end here. On our next post we will learn how lighthouses gave the National Guard its start.

Happy Puzzling!