The lighthouse at the Butt of Lewis is one of over 200 that are located around Scotland's wild coastline. Operated and maintained by the Northern Lighthouse Board they warn ships of dangerous waters and provide safe passage.
Standing 37m high and 52 metres above sea level, the lighthouse is built on the most northerly point of Lewis. The Station's claim to fame was getting into the Guinness Book of Records some years ago as the windiest spot in the United Kingdom. Designed and built by David and Thomas Stevenson, little is known of its history. Unlike most lighthouses it is of brick construction and has remained unpainted.
The Butt is also the site of one of a network of 14 ground-based reference stations providing a Differential Global Positioning System (DGPS). This is a satellite positioning system provided for mariners.
A Principal Lightkeeper and two Assistants with their families lived at the lighthouse until the light became automated in 1998. The families were quite self-sufficient and kept cows and sheep at the lighthouse. Light keeping was a remote, lonely and hard existence. At night each keeper was required to keep a watch in the Lightroom to ensure that the light flashed correctly to character. During daytime Keepers were engaged in cleaning, painting (if necessary) and generally keeping the premises clean and tidy.
The original lens at the Lighthouse was a Fresnel lens, so called after its French inventor, Augustin Fresnel. The lens was made from a series of perfectly polished crystal glass lenses set into a bronze structure. In 1985 the lens was replaced with an array of sealed-beam electric lamps, similar to those used by locomotives for headlights. Now automatic, when daylight and rises between set levels a small light sensor automatically switches the light on and off. The Light is monitored 24 hours a day from a remote centre and is visited on a regular basis by a local person carrying out basic maintenance and cleaning. Once a year the Northern Lighthouse Board Technicians visit to carry out maintenance.
For over 150 years Robert Stevenson and his descendants designed most of Scotland's lighthouses. Battling against the odds and the elements, the Stevensons constructed wonders of engineering that have withstood the test of time, an amazing historical achievement.
Looking at the geology of the area it's hardly surprising that a lighthouse was needed to warn ships of the fearful dangers of the jagged rocks of this coastline. 500 million years ago the Islands, and indeed the whole of Scotland, was joined to Greenland but for the last 60 million years has, with the rest of Europe, been drifting away geographically from what we now call the North American Continent. The Islands are made up of two main types of rock, the oldest - Lewisian Gneiss - being formed by volcanic pressure and then overlaid with Sandstone Conglomerate considerably later after glaciers engulfed the land and the sea levels rose. Throughout the periods of formation the rocks were layered with minerals like quartz and biotite mica.
Robert Stevenson's talented family also included the famous writer Robert Louis Stevenson (his grandson). Visits with his father to remote lighthouses are thought to have inspired his books, Kidnapped and Treasure Island.
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