Mad as a Lighthouse Keeper — Not the Solitude, but the Mercury

photo_point_mendocinoWe recently posted about three killer lighthouses.  It turns out that lighthouse keepers had more to worry about than simply storms and terrible conditions. In the 19th century, lighthouse keepers had a high frequency of madness and suicide.  Many assumed that they went mad from solitude and the demands of the job. It turns out it was something simpler and more sinister.

Fresnel lenses were the great lighthouse innovation of the 19th century.  The lenses developed by French physicist Augustin-Jean Fresnel greatly increased the intensity and range of the lighthouse beacon. For rotating lights, just as importance as the strength of the light, however, was maintaining a specific speed of rotation, so that if the chart said that the light flashed every twenty seconds, the light, in fact, rotated so that the light was visible every twenty seconds.  The best near zero-friction bearing of the day was created by floating the light and the lens on a circular track of liquid mercury.  When dust, dirt or other impurities built up in the mercury, part of the light house keeper’s job was to strain the mercury through a fine cloth.

Though not understood at the time, mercury is a deadly poison. One of the symptoms of mercury poisoning can be the onset of madness. Those involved in the manufacture of hats in the 18th and 19th centuries also suffered from mercury poisoning, becoming as “mad as a hatter” as the old saying went.  Like the hatters of their day, the light house keepers were being driven mad by exposure to mercury fumes. The solitude was not driving the lighthouse keepers mad. They were being poisoned by the lighthouse itself.  Perhaps we should add “mad as a lighthouse keeper” to the lexicon.

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5 Responses to Mad as a Lighthouse Keeper — Not the Solitude, but the Mercury

  1. Dave Cowan says:

    Hatters and keepers. Innocent enough names for maddening professions.

  2. pete says:

    In Scotland we also had the Flannan Isles incident:

    http://sjhstrangetales.wordpress.com/2012/01/10/the-flannan-isles-lighthouse-mystery/

    For those interested in lighthouses I must recommend “The Lighthouse Stevensons” by Bella Bathurst.

  3. Bob Stockton says:

    Hence Lewis Carroll’s “Mad Hatter.” Interesting.

  4. walt says:

    Alas, Today’s lighthouses are un-manned
    Ironically Mercury is in Compact Fluroescent Lamps, CFL’s, endemic to
    today’s homes
    Mercuy is still used in Manometers. However, today there are non-
    mercury substitues for manometery. Today’s Submarines are Mecury Free.
    Years ago, Mercury Seals were used in Sewage Plant Comminuters
    Gasoline is lead Free.
    And i don’t thinks kids drink garden hose water, their helicopter parents wont stand for it.
    What will our New life expectnacies be?

  5. Pingback: Why did lighthouse keepers go mad? | Dj Matioka Blog

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