Schiehallion

Seen over the River Tay

Schiehallion or Shehellien ( Gaelic: SIDH Chailleann, pronounced IPA: [ ʃixaʎən̪ ˠ ] ) is a mountain in the Scottish Unitary Authority of Perth and Kinross. He is very popular because of its simple ascent and spectacular view for hikers. In 2000 it was estimated that every year climb the mountain 17500-20000 hikers. Since 1999, the east side of the mountain is owned by the John Muir Trust.

The Schiehallion Experiment

The isolated position of the Schiehallion and its regular shape meant that Charles Mason the mountain in 1774 chose to estimate by an experiment for the first time the mass of the Earth. Two measurement points were selected on different sides of the mountain. The deflection of their Lotrichtungen by the mountain's bulk should provide an approximate measure of Newton's gravitational constant G. From this constant could be concluded that the average density and mass of the Earth. The now called the deflection of the vertical angle was determined by measuring the two elevation angle of a star and comparison with the distance between the two points.

The experiment itself was, however, not carried out by Charles Mason, who only chose the mountain, but the court astronomer Nevil Maskelyne was the British in collaboration with the mathematician Charles Hutton ¹), who also invented the contour lines during the measurements. ¹) Several sources name instead of his contemporaries Charles Hutton James Hutton, a well-known geologist who also certain from the rock density of the mountain to 2.7 g / cm ³. See also and

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