Timelight Machine (Bridge to the Past)
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Fresnel Lens at Highlands
The first Fresnel lenses used in the United States were brought from France by US Navy Commodore Matthew C. Perry in 1841 and installed in the 1828-built Twin Lights Lighthouse. The inventor, Augustine Fresnel, had revolutionized the lighting of lighthouses with development of the lens bearing his name.
The Twin Lights lenses resembled huge bee hives of glass surrounding a light and worked on the principles of physics. The light of the illuminant was reflected and refracted (bent) into an intense beam drawn to a magnifying glass in the center of the lens. That process made it capable of producing 6,000,000 candlepower and its beam could be seen for 22 miles. Sailors reported seeing the light's glow in the night sky as far as 70 miles at sea. The machinery used to rotate the light was driven by a 700 pound weight of the clockwork mechanism. It had to by rewound every six hours. The lens revolved every ten seconds and flashed every five seconds. In 1898, the original South Tower lens was replaced with one of the world's largest bivalve lenses ever produced. And in that year the South Tower lens was electrified, America's first lighthouse to e so powered. The brilliant electric light produced 25,000,000 candle-power and was the most powerful light installed in a lighthouse in the United States. At the same time, the light in the North Tower was discontinued although kept in place if needed.
After the light was installed and working, many residents complained of the brilliance of the light. They said the light shining on the landward side kept their cows awake at night and the animals refused to give milk in the morning. The problem was corrected with the installation of blackout panels on the landward sides of both towers.
In 1917, it was necessary to replace the electric arc light because it was so costly to operate. It was decided to install an incandescent oil vapor light. That resulted in a decrease of candlepower to 710,000, but it was still powerful enough to guide shipping off the coast of New Jersey.
In 1931 the light was converted back to electricity and its candlepower increased to 9,000,000, thus making it again America's most powerful light. Three 500-watt bulbs served as the light source for the lens.
As modern methods of warning ships, such as radar and radio beacons were developed, the Twin Lights Lighthouse became obsolete by governmental standards and the light station was decommissioned in 1949.
The Boston Museum of Science acquired the South Tower Fresnel lens from the US Coast Guard in 1951 and placed it on exhibit. With the cooperation of the Twin Lights Historical Society, Rumson Garden Club and the New Jersey Division of Parks and Fo,restry, the Fresnel lens was safely returned home in March of 1979. It is now exhibited in the building that housed the generating equipment for lighting the lens. The South Tower Fresnel lens may be seen during museum hours along with its clockwork mechanic
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