Screwpiles: The Forgotten Lighthouses

universally adopted colza oil. In the early 1860s, the Lighthouse Board was actively experimenting with lard oil. In his October 1864 report, Joseph Henry, chairman of the Committee on Experiments for the Lighthouse Board, noted the success of large-scale experiments with lard oil. He stated, “Lard-oil has been found to succeed in the coldest weather, and to be capable of yielding more light with the same lamp than sperm oil.” By 1867, U.S. Lighthouse Service lamps universally used lard oil as their illuminant. 7 Although experiments were conducted with kerosene (or mineral oil) as well, an uncertain supply, along with concerns about safety, delayed its use. In its 1875 report, the Lighthouse Board recognized that mineral oil could be used in fifth-order and sixth-order lamps, but more development was required before it could be used in the higher-order lamps. Improvements in oil supply, as well as improvements in lamp design over the next several years, finally allowed kerosene to be the principal illuminant throughout the service by 1885. 8

All of the James River lighthouses continued to use kerosene to light their sixth-order lamps until they were dismantled.

James River Lighthouse lantern plans, 1853 National Archives

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