Lighthouse Glossary
"Keep The Lights Shining"

A modern type of light presently used in many lighthouses to produce a characteristic. Originally manufactured for use at airports, but also, now, used by the Coast Guard at major seacoast light stations.

Argand Lamp
A hollow wick oil lamp.

Vertical metal bars which hold the glass of the lantern room.

A convex lens used to concentrate (regract) light.

A narrow elevated walkway, allowing the keeper access to light towers built out in the water.

The light pattern given to a particular lighthouse. Patterns include quick flashes, occulting flashes (3 second darkness), period flashes (every 2, 4, 15 etc.seconds), equal interval, group flashing, etc.

Any light structure that sits out in the water away from the beach or pier.

A shape which provides the mariner navigation information during daylight hours: red triangle--keep it to the right entering port, green square keep it to the left entering port, etc.).

Unique color and/or pattern that identified an aid to navigation during daylight hours.

Fixed Light
A steady, non-flashing beam.

Fog Signal
A sound signal to warn mariners of obstructions or indicate a harbor entrance. Various sound signals were used over the years: bells, whistles, sirens, trumpets, horns and most recently electronic horns. Wave activated signals include bell, gong and whistle buoys.

Fresnel Lens
Beehive shaped lenses of brass and glass prisms which redirect light from the source into horizontal beams. Fresnel lenses come in nine sizes; hyper radial, meso radial, 1st through 6th order and a 3 1/2 order.

On a lighthouse tower, a railed platform, walkway or balcony located outside of the watchroom and/or lantern room.

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

The device which produces light; oil powered (whale, lard or kerosene) or electric.

Lantern Room
The metal and glass room placed on top of towers to protect the lens, optic, etc.

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

The tower or tower attached to a dwelling which supports an optic or lens. Usually consisting of a very bright light atop of tower and often a foghorn, siren, and radio beacon.

A complex which contains a lighthouse and may also contain dwellings, fog signal building, boat house, oil house and other structures.

A book for maintaing records.

The apparatus used to produce the light (lens, beacon, etc.)

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

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

A person who studies or is interested in lighthouses.

A structure extending into navigable waters for use as a landing place, or to protect or form a harbor.

A transparent piece of glass that refracts or disperses light.

Range Lights
Used by mariners to fix their position in open water and guide them into port. Range lights usually appear in pairs and are 1000 feet apart.

Bend or throw back light.

Bend or slant rays of light.

Revolving Light
A rotating beam of light that produces a flash or characteristic.

A shallow area, such as a sandbar or rock formation.

Spider Lamp
Shallow brass pan containing oil and several solid wicks.

Stag Light
A lighthouse with no family living in it---occupied by men only.

Structure supporting the lens and 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 ratating lenses) were also located there.

Weight Well
A bowl shaped item designed to capture the descending clock-work counter-weight as it rotates.

A nickname given to lighthouse keepers derived from the task of trimming the wick of the lamps.

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