Glossary of Lighthouse Terms

ARGAND LAMP A hollow wick oil lamp. (see wick)

AEROBEACON A modern-day type of light presently used in many lighthouses to produce a characteristic.

ASTRAGAL Metal bar (running vertically or diagonally) dividing the lantern room glass into sections.

BULLSEYE A convex lens used to concentrate (refract) light.

CHARACTERISTIC Individual flashing pattern of each light.

DAYMARK Unique color scheme and/or pattern that identifies a specific lighthouse during daylight hours.

FIXED LIGHT A steady non-flashing beam.

FOG SIGNAL A device (such as a whistle, bell, canon, horn, siren, etc.) which provides a specific loud noise as an aid to navigation in dense fog.

FRESNEL LENS A type of optic consisting of a convex lens and many prisms of glass which focus and intensify the light through reflection and refraction.

FUEL A material that is burned to produce light (fuels used for lighthouses included wood, lard, whale oil, tallow, kerosene.) Today, besides electricity and acetylene gas, solar power is also used.

GALLERY On a lighthouse tower, a platform or walkway or BALCONY located outside the watchroom (main gallery) and/or lantern room (lantern gallery.)

KEEPER The person who takes care of the light in the lighthouse. (The Head Keeper is responsible for the operation of a light station.)

LAMP The lighting apparatus inside a lens.

LENS A curved piece of glass for bringing together or spreading rays of light passing through it.

LIGHTHOUSE A lighted beacon of major importance in navigation.

LIGHT STATION A complex containing the lighthouse tower and all of the outbuildings, i.e. the keeper?s living quarters, fuelhouse, boathouse, fog-signaling building, etc.

LOG A book for maintaining records, similar to a diary.

NAVIGATION Travel over water.

ORDER Size of the Fresnel lens which determines the brightness and distance the light will travel.

PARABOLIC A bowl-like metal device, silver plated, REFLECTOR with a small oil lamp in the center.

PHAROLOGIST One who studies or is interested in lighthouses.

PRISM A transparent piece of glass that refracts or disperses light.

REFLECT Bend or throw back light.

REFRACT Bend or slant rays of light.

REVOLVING LIGHT One that produces a flash or characteristic.

SPIDER LAMP Shallow brass pan containing oil and several solid wicks.

STAG LIGHT A lighthouse with no family living in it, i.e. inhabited by men only.

TOWER Structure supporting the lantern room of the lighthouse.

WATCH ROOM A room immediately below the lantern room or SERVICE ROOM where fuel and other supplies were kept where the keeper prepared the lanterns for the night and often stood watch. The clockworks (for rotating lenses) were also located there.

WICK SOLID - A solid cord used in spider lamps that draws fuel up to the flame by capillary action.

HOLLOW - A concentric cotton wick used in Argand and other lamps.

"WICKIE" - A nickname given to lighthouse keepers derived from the task of trimming the wick of the lamps.
The U.S. Lighthouse Society originally designed this packet to furnish teachers with basic information about lighthouses, their purpose, history, operation and technology in a form presentable to young students. with the society's permission the U.S. Coast Guard Historian's Office is posting this modified version with additional photographs and information.

The U.S. Coast Guard Historian's Office would like to thank Mr. Wayne Wheeler and the other members of The U.S. Lighthouse Society who produced and distributed the original version of this curriculum.

For more information on lighthouses, teachers and students should contact The U.S. Lighthouse Society, 244 Kearny Street, San Francisco, Ca 94108 or consult the lighthouse web pages on The U.S. Coast Guard Historian's web site.