Gibbs Hill Lighthouse
Encyclopedia
The Gibbs Hill Lighthouse is the taller of two lighthouses on Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...

, and the first of only a few lighthouses in the world to be made of cast-iron. This is because at that time, steel still was not able to be bent. The optic consists of a Fresnel lens
Fresnel lens
A Fresnel lens is a type of lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design...

 from 1904 revolving on steel bearings. However for most of its history, the lens revolved on a bed of 1,200 pounds of mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

. While it is certainly not extremely tall in lighthouse standards, the hill that it stands on is one of the highest on the island. The light's focal plane on Gibbs Hill Lighthouse, therefore, is at 354 feet (107.9 m) above sea level. Single-engined airplanes can see its flashes from over 100 miles (160.9 km) away. The lighthouse has 185 steps to the top in eight flights. Until 1964, most of the light was run by hand, but in June of that year, the whole system was automated and runs on electricity. Sixty-thousand people ascended the lighthouse in 1985, and it continues to be a popular tourist attraction.

A radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 antenna for marine shipping was installed atop the lighthouse in 1987 supported on a steel space frame fixed at the original bolt locations. The radar and supporting frame were undamaged in September 2003 despite the oscillation of the tower during Hurricane Fabian
Hurricane Fabian
Hurricane Fabian was a powerful Cape Verde-type hurricane that hit Bermuda in early September during the 2003 Atlantic hurricane season. Fabian, the sixth named storm, fourth hurricane, and first major hurricane of the season, developed from a tropical wave in the tropical Atlantic Ocean on August 25...

. This movement caused two gallons of mercury to slop out of the lens support trough and put the light out of operation. The 1904 lens was repaired in 2004 with steel bearings to replace the mercury.
At the base of the tower is the Lighthouse Tea Room, a restaurant converted from the lighthouse keeper's former living quarters, where breakfast, lunch, and dinner are served daily.
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