Monday, December 07, 2015

Early Lighthouse Lamps

In past posts I have written about the Fresnel Lens, a technological leap in navigational lighting. A Fresnel Lens, invented in 1822, is a glass dome of prisms and bull's-eyes. Light is concentrated at its center into parallel rays that are intensified with a magnifying glass.

Click here to read more about the Fresnel Lens and the Ocracoke Lighthouse:

But what methods were used to illuminate American lighthouses prior to 1822? Below is a partial list, in chronological order, of various devices and mechanisms:
  • Simple pole lights upon which were burned bales of pitch-soaked oakum (loose fiber obtained by untwisting old rope).
  • Tallow candles set in chandeliers and enclosed in a lantern room (until the mid-1700s).
  • Oil Lamps 
    • Simple, open reservoirs filled with oil (whale oil was most highly prized) into which several cotton-rope wicks were placed. 
    • Pan lamps: enclosed trays with as many as two dozen wicks. Some lighthouses suspended more than one pan lamp in the lantern room. "Compass lamps" were round.
    • Bucket lamps: larger devices that could hold as much as two gallons of oil, with numerous metal spouts into which were threaded thick rope wicks.
    • Argand lamps: invented by French physicist, Francois-Pierre Ami Argand, employed a much cleaner burning hollow wick encased in a metal tube, and a glass chimney.
    • Reflector lamps: an Argand lamp with an added silver-coated parabolic reflector.
    • Winslow Lewis lamps: an Argand lamp modified with a convex, bottle glass magnifier.
For fuel, kerosene replaced whale oil after the Civil War, and Fresnel lenses replaced other devices by the mid-19th century. Fresnel lenses remain the "gold standard" and are still in use in US lighthouses today.

Eventually all lighthouses were electrified. The Ocracoke lighthouse was fitted with a Fresnel lens in 1854, and electrified in 1929.

Our latest Ocracoke Newsletter is the story of Capt. Horatio Williams and his schooner, the Paragon. You can read the story here:

1 comment:

  1. Anonymous6:13 PM

    Because of this post on lighthouses I spent 2 hours researching Winslow lamps, Fresnel lenses, pan lamps and most everything else you was fun and interesting. Thank you for spuring me on ! Good stuff.