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Lighthouses. By Peter D Aberdeen High School, 1999. Lighthouse History. First lighthouses -found around Mediterranean Sea -consisted of fires on top of coastal hills

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Presentation Transcript
lighthouses
Lighthouses

By Peter D

Aberdeen High School, 1999

lighthouse history
Lighthouse History
  • First lighthouses -found around Mediterranean Sea -consisted of fires on top of coastal hills
  • First traditional lighthouse structure -Pharos light of Alexandria constructed around 280 B.C. 280 feet tall -reflectors contained wood fire -could be seen for 35 miles
lighthouse history 2
Lighthouse History- 2
  • Ancient Lighthouses -Portus, Italy 46 A.D.

-Boulongne, France

-Dover, England

-Genoa, Italy 1139

-Leghorn 1304

  • First in U.S.

-Boston Light near Boston Harbor, 1716

lighthouse history 3
Lighthouse History - 3
  • U.S. lights maintained and upkept by U.S. Coast Guard since July 1, 1939.
  • Worldwide, more than 30,000 lights today
  • First lightship stationed in Thames estuary in 1732
fresnel lens
Fresnel Lens
  • First constructed in 1822 by French physicist A. Fresnel
  • Uses concentric rings of glass prisms to bend and focus light into a narrow beam
  • Often as tall as twelve feet
concord point light 2
Concord Point Light - 2
  • Built in 1827 at the mouth of the Susquehanna River in Havre De Grace
  • 36 foot tower, originally built with tin reflector, upgraded to fresnel lens in 1854
  • Decommissioned in 1975

Link to information on Concord Point Lighthouse and other lighthouses