Category
page 1Lighthouse fixtures
Fresnel lens
compact composite lens

foghorn
thumb|right|Two roof-mounted diaphone foghorns at [[Split Rock Lighthouse]]
A foghorn or fog signal is a device that uses sound to warn vehicles of navigational hazards such as rocky coastlines, or boats of the presence of other vessels, in foggy conditions. The term is most often used in relation to marine transport. When visual navigation aids such as lighthouses are obscured, foghorns provide an audible warning of rock outcrops, shoals, headlands, or other dangers to shipping.
Argand lamp
Type of oil lamp
light characteristic
description of navigational light
Carcel burner
oil lamp with a clockwork pump mechanism

Dalén light
automatic controlled acetylene gas lighthouse
hyperradiant Fresnel lens
obsolete Fresnel lens used in lighthouses