A Light That Saves Lives
IT WAS an arduous five-week Atlantic crossing in the late 19th century. The passengers were expecting to see land any day. Then a light appeared, a lonely star on the horizon. But it was not a star; it was a lighthouse. “At the sight of the light, we threw ourselves on our knees and gave thanks to God,” a passenger later said. The light guided them safely to their destination. Not all those early voyages, however, ended so well.
December 22, 1839, was a fair, sunny day on the New England coast of North America. The keeper of the lighthouse at Plum Island, Massachusetts, thought he could safely leave the island in his little rowboat, take his wife shopping, and be back before dark. But while they were away, a wind began to blow. A storm was coming, and fast. Soon sky and sea fused into a gray, howling mass of rain, foam, and spray. The keeper tried desperately to get back to the island but in vain. That night the lighthouse remained dark.
Near midnight, the ship Pocahontas, struggling to find the river and harbor entrance normally signaled by the lighthouse, searched in vain. Instead, the ship hit a sandbar. Its back was broken, and it sank with the entire crew on board. Just before dawn the Richmond Packer, heading for the same port, also came to grief, but only one life was lost, that of the captain’s wife.
Maritime history is replete with disasters that beacon lights might have prevented. “In olden times, many a ship was navigated safely across the ocean, only to be wrecked as it tried to make port,” says the book America’s Maritime Heritage. “The most dangerous part of an ocean trip was the last few miles, as a ship approached and finally sighted land.”
According to lighthouse historian D. Alan Stevenson, between 1793 and 1833, the average number of ships wrecked annually on British shores increased from 550 to 800. More lighthouses were needed, as were better lights.
In some countries, including England and the United States, sailing was made even more dangerous by the infamous moon cussers, villains who set up false lights to lure ships onto rocks, only to plunder them there. Survivors were often killed; moon cussers wanted no witnesses. Under a bright moon, however, their ploy would fail. Hence the name moon cussers. Eventually, though, more and better lighthouses helped put these thieves and murderers out of business.
The First Beacons
The earliest mention of beacons is in the Iliad. “At the going down of the sun the line of beacon fires blazes forth,” it says. The book Keepers of the Lights says that “the original beacons were nothing but huge fires of logs, sometimes kept in stone cairns, and later in big iron cages, that were allowed to burn out at frequent intervals with tragic results.”
Then, about 300 B.C.E., on the island of Pharos, at the entrance to the harbor of Alexandria, Egypt, arose the world’s first true lighthouse, the Pharos of Alexandria. A magnificent masonry structure between 350 and 400 feet [100-120 m] high (about 40 stories), it was the tallest lighthouse ever built. One of the Seven Wonders of the World, it lasted about 1,600 years until it was toppled, probably by an earthquake.
The Romans erected at least 30 lighthouses, from the Black Sea to the Atlantic. But when the empire fell, commerce slowed and lighthouses fell into darkness and disrepair. Construction began again about 1100. A celebrated lighthouse of the new era was the Lanterna of Genoa, whose keeper in 1449 was Antonio Columbo, uncle of explorer Christopher Columbus.
The first lighthouse erected in the open sea was a wooden one built by Henry Winstanley in 1699 on the treacherous Eddystone Rocks off Plymouth, England. He was proud of his accomplishment. While fishing from his lighthouse, says the video documentary Guardians of the Night, Winstanley would say: “Rise up, sea. Come and put my work to the test.” One day in 1703, the sea obeyed. Winstanley and his lighthouse vanished without a trace.
Commemorating the friendship of the peoples of the United States and France, the 302-foot-high Statue of Liberty, in New York Harbor, doubled for some time as a navigational aid. For 16 years three keepers took turns keeping the flames bright in her torch. “From her beacon-hand glows world-wide welcome,” says a sonnet at her pedestal.
From Flames to Xenon Flashtubes
Coal, candles—even candelabras—and oil eventually replaced wood as the illuminant in lighthouses. Attempts were made to use reflectors to focus the light, but smoke and soot from the fire tended to blacken them. In 1782, however, Swiss scientist Aimé Argand invented an oil lamp that directed air upward through the middle of a cylindrical wick and out through a glass chimney. Once they would stay clean, parabolic reflectors (shaped like the mirrors in car headlights) became popular in lighthouses. A good reflector increased the light intensity some 350 times.
Another big stride came in 1815 when French physicist Augustin-Jean Fresnel invented the most efficient lens ever to be used in lighthouses. Prior to Fresnel’s invention, the best mirror systems—using Argand lamps, which remained popular for over 100 years—produced about 20,000 candlepower.* Fresnel lenses boosted this to 80,000—about the same power as a modern-day car headlight—and that with just a burning wick! Pressurized oil burners were invented in 1901, and it was not long before Fresnel units emitted up to one million candlepower. About the same time, acetylene gas came into use and profoundly affected lighthouse technology and automation, thanks largely to the work of Nils Gustaf Dalén, of Sweden. Dalén’s automatic sun valve—an off and on switch that regulates acetylene gas flow by responding to sunlight—earned him the Nobel Prize for Physics in 1912. Electric filament lamps became popular in the 1920’s and remain the chief illuminant to this day. When mated with a Fresnel lens, a bulb of just 250 watts can emit several hundred thousand candlepower. Nowadays, the most powerful lighthouse in the world, a lighthouse in France, can crack open the night sky with a blinding shaft of 500 million candlepower.
A recent innovation is the xenon flashtube. It gives off a brilliant flash just millionths of a second long. Because the light pulse is so brief and intense, it stands out against a background of other lights.
Floating lighthouses, or lightships, were put to work where it was impractical to build a tower. Like towers, though, lightships have a long history. The first was a Roman galley commissioned in Julius Caesar’s time. High on the mast, an iron brazier of burning charcoal lit up the night sky—and dropped embers onto the sweating bodies of the slave oarsmen chained to their stations below.
The first latter-day lightship went to work in 1732 in the Thames estuary, near London. Thereafter, the number of lightships increased. For many years ships entering and leaving New York Harbor were guided by the lightship Ambrose. In recent years, however, lightships have given way to automatic light buoys and light towers, which are metal structures that resemble offshore oil wells.
When Fog and Storm Smother Lights
Even the most powerful light is hampered when there is heavy fog and rain—times when beacons are needed the most! A solution, although an imperfect one, is sound—a very loud and regular sound. For this reason, many lighthouses are equipped with powerful acoustic devices such as bells, foghorns, sirens and, for a time, even cannons! In fact, some lighthouses used cannons as late as the 1970’s.
Sound waves, however, are subject to the vagaries of the atmosphere. Differences in temperature and humidity in the layers of air above the water can play tricks with sound, sometimes bending it upward, sometimes downward. Additionally, just as a pebble can be made to bounce on a pond, so a blast of sound can bounce right over a ship and not even be heard! But problems aside, acoustic signals can usually be heard miles away.
The End of an Era
As automation arrived, lighthouse keepers became redundant. Radar, radio, sonar, and satellite navigation have now overtaken even the lighthouse itself, and many have been decommissioned. But we cannot seem to let them go. To many people, lighthouses are a symbol of light and hope in a dark world, and they continue to inspire photographer, artist, and poet alike. In an effort to preserve these handsome old buildings, lighthouse societies have sprung up around the world.
Some lighthouses now offer unique accommodations for visitors keen to sample the life of a lighthouse keeper, albeit a more pampered one. Other visitors simply want to enjoy solitude—to hear nothing but the lonely cry of gulls and the rumble of the surf. In certain parts of the world, lighthouses also furnish an excellent vantage point for watching whales, birds, and seals. The keepers at Alexandria and Christopher Columbus’ uncle at Genoa probably spent their idle moments doing much the same.
Now replaced by the candela. Previously, the international candle, measured in candlepower, was the luminous intensity of a light in a given direction as compared to that of a standard candle.
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Two Courageous Women
The story of lighthouses includes accounts of remarkable courage and dedication, often on the part of women. Grace Darling (1815-42) risked her life to save nine survivors of a shipwreck near her father’s lighthouse at the Farne Islands, off the northeast coast of England. At her insistence, she and her father rowed through a perilous sea to the wreck, put the survivors in the dinghy, rowed back to the lighthouse, and cared for them until help arrived. A memorial has been erected in her memory.
Abigail Burgess was the 17-year-old daughter of the keeper of the Matinicus Rock lighthouse, off the coast of Maine in North America. One day in January 1857, her father had to leave the lighthouse but then could not get back for four weeks because of bad weather. Abbie, as she was called, took charge. She also tended her ill mother and supervised her three siblings, who were too young to help with lighthouse duties. Abbie writes: “Though at times greatly exhausted with my labors [keeping a light before the advent of electricity was hard work], not once did the lights fail. Under God I was able to perform all my accustomed duties as well as my father’s.” The following winter Abbie once again had to take charge. This time she and her family were reduced to a daily allowance of one egg and one cup of cornmeal. But the light never failed.
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The Fresnel Lens
The Fresnel lens is actually a compound lens, or lens panel, with a central lens surrounded by curved glass prisms. Fresnel lens panels can be joined together to form a glass barrel that completely encircles the light source. Each panel concentrates light into a horizontal pencil beam. More panels mean more beams of light, like spokes radiating from the hub of a wheel. As the barrel rotates around the light source, the spokes of light whip around the horizon. The number of beams, the time interval between beams, and even their color are just some of the factors that give each lighthouse a unique light signature, or characteristic. Ships carry a light list so that mariners can identify each lighthouse en route.
South Street Seaport Museum
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Peggy’s Cove, Nova Scotia, Canada
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Statue of Liberty, New York
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Weser River, Germany
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Washington State, U.S.A.
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The Complete Encyclopedia of Illustration/J. G. Heck