Farallon Island Light is a lighthouse

Lighthouse

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....

 on Southeast Farallon Island

Farallon Islands

The Farallon Islands, or Farallones , are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, USA. They lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. One of the highest lights in California, it was constructed in 1855 to warn ships approaching San Francisco from the
west away from the rocky islands. In later years it was shorn of its lantern, but it remains in use.

History

Farallon Island Light was constructed on southeast Farallon. After the tower was complete, it proved too small to house a first-order 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...

, and the tower had to be torn down and rebuilt. The lighthouse was lit for the first time in December 1855. In 1939, the United States Coast Guard

United States Coast Guard

The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

 took over the lighthouse when the United States Lighthouse Service

United States Lighthouse Service

The United States Lighthouse Service, also known as the Bureau of Lighthouses, was the agency of the US Federal Government that was responsible for the upkeep and maintenance of all lighthouses in the United States from the time of its creation in 1910 until 1939...

 merged with it. The Coast Guard maintained a presence until 1972. By that time, the top of the tower and the Fresnel lens had been removed, and an automated aero beacon was placed on the tower.

Historical Information from Coast Guard web site:

This lighthouse is situated on the highest peak of the southeast Farallon. It was built in 1855 in the busy days which followed the gold rush

Gold rush

A gold rush is a period of feverish migration of workers to an area that has had a dramatic discovery of gold. Major gold rushes took place in the 19th century in Australia, Brazil, Canada, South Africa, and the United States, while smaller gold rushes took place elsewhere.In the 19th and early...

 when clipper ships

Clipper ships

At the 'crest of the clipper wave' year of 1852, there were 200 clippers rounding Cape Horn.Notable examples of the clipper ship include:* Archibald Russell, 1905, a steel-hulled 4-masted barque, 291.3 ft. x 43 ft. x 24 ft., built by Scott Shipbuilding and Engineering Co of Greenock...

and other sailing vessels were sailing in to San Francisco in large numbers. That there was need for a light on these dangerous rocks is evident when clippers like the Golden City which sailed from New York in 1852 reported that she was detained 5 days off the Farallons in fog. Stone for the construction of the lighthouse was quarried on the island and inside this masonry was a lining of brick. The extremely sharp slopes of the island and the jagged nature of the rock were serious obstacles to construction work. The bricks used in the tower were carried up the rock in bundles of four and five on the backs of men. After the completion of the tower a mule was kept on the island for years to carry supplies between the various parts of the station. At one time this mule was the oldest inhabitant. A number of years ago the gathering of birds’ eggs, which were sold on the San Francisco market, was carried on here extensively and seals were also hunted commercially. These practices were finally terminated by the Federal Government. The Farallon Light Station was equipped with a radiobeacon as well as with a powerful light and fog signal.