Schiehallion

Schiehallion is a steep, cone-shaped mountain in the Scottish Highlands near Loch Tummel, Loch Rannoch and Loch Tay. Its Gaelic name means ‘fairy hill of the Caledonians’, and it has long been linked to folklore about the Cailleach Bheur, the winter goddess. The mountain is made of quartzite, a hard rock that gives its slopes a pale pink cast. Sheep once grazed its lower reaches, and red deer still roam the higher ground. In the 18th century an experiment to weigh the Earth was carried out on its slopes. The mountain’s regular shape made it ideal for the Schiehallion experiment of 1774. Astronomer Royal Nevil Maskelyne and mathematician Charles Hutton measured how the mountain’s mass pulled a pendulum off true vertical. From these readings they calculated the Earth’s mean density and, indirectly, its total mass. The path once used by the surveyors is now a popular walking route. Today walkers start near Brae of Foss and follow a broad ridge to the summit in about two and a half miles. The view from the top includes Ben Nevis to the west and the surrounding lochs below. Heather and blaeberry colour the slopes, while limestone pavements shelter uncommon plants such as wood anemone. The John Muir Trust now owns the eastern side and has rebuilt the main path to protect the mountain from erosion.