Lighthouse lenses and other things     Argand Lamp Photo credit: U.S. Coast Guard      The earliest lights on the Great Lakes used Argand lamps.  These were developed by Aimee Argand of Geneva and used a burner with a hollow wick in a glass chimney.       Fresnel Lens      Invented in 1822 by French physicist Augustine Fresnel, these big prismatic glass lenses were designed to snatch every flicker of light from even the smallest lamp and concentrate it into a powerful beam that could be seen from dozens of miles away.  Fresnel's elegant lenses did their job so well that they soon became standard equipment in lighthouses throughout much of the world.      The new Fresnel technology, however, was virtually ignored for several decades in the United States, where Winslow Lewis's far less effective parabolic reflectors were employed right up until the middle of the nineteenth century.  One reason the United States was slow to adopt the Fresnel system was the considerable expense of the highly polished lenses, which had to be imported from France.  Another was the bureaucratic fussiness of Stephen Pleasonton, the U.S. Treasury auditor who served for many years a head of the so-called lighthouse establishment.  Displaying undisguised favoritism for Lewis, a personal friend, Pleasonton continued to equip U.S. lighthouses with his outdated reflectors even though they were demonstrably inferior to Fresnel lenses.  Following the release of a highly critical report written by Lewis's own nephew, Pleasonton was forced into retirement.     A Modern Plastic Lens   At many light stations Fresnel lenses have been replaced with modern plastic optics.  Interestingly, the newer lenses rely on old fashioned Fresnel technology. From American Lighthouses - A Comprehensive Guide by Bruce Roberts & Ray Jones         Fog Signals      Fog signals were maintained at many lighthouses.  In the beginning, they were only hand rung bells.  In 1851, mechanically operated systems were in use.  By 1900 nearly all fog signals were steam powered.  Steam signals were eventually replaced with ones using compressed air as it took the steam signals almost 45 minutes to reach the necessary steam pressure before they could be sounded.     Portland Head Fog Bell West Quoddy Fog Bell Pemaquid Point Fog Bell Monhegan Island Light Fog Bell     A close up shot of the sign on the Pemaquid Bell Tower.   Fueling the Light Wood was the fuel for the first signal fires, followed by coal and then oil.  This was followed by electric filament lamps.  In the early 1920's, kerosene, in vapor form, was a commonly used fuel but the trend quickly faded.  This was followed by Acetylene gas and was widely used around 1910.           Opening Page More Lighthouses      Maine Lighthouses             Vacation Photographs                              by Grandma Carol   Outer Banks    Lighthouses              Vacation Photographs                               by Grandma Carol   Lighthouse Lenses and Other Things Haunted Lighthouses   Loyal Lighthouse Ladies   The Life of  a Lighthouse Keeper and His Family   Forever Christmas Some Of My Collection   About Grandma Carol Free Lighthouse Borders, Backgrounds and Graphics      The photo used in the border was taken at Portland Head Light by   Grandma Carol on June 16, 2001