Mount Shiehallen is found in Perth and Kinross. Its name is an anglicized version of the Gaelic Sith Chailleann which is generally translated as “Fairy hill of the Caledonians”. Not the highest of the mountains, it rises some 3,553 feet (1083 meters) and is almost perfectly conical in its shape. The shape looks suspiciously like an inactive volcano, but in fact it is not.



The mountain stands basically alone and interestingly enough the summit of the mountain lies at virtually the center of the latitude and longitude of Scotland.

The mountain is well known to hikers, and the amount of foot traffic seems to have been responsible for the erosion if the foot path which led to extensive repairs about 20 years ago. From Shiehallion’s peak there are wonderful views of the surrounding areas. The mountain itself is a feature that attracts many tourists to Loch Tummel where the eastern slope of the mountain dominates the landscape.

The mountain is known its plant life and interesting geology. People have been active on the mountain from about 1,000 years before the current era.

One of the more interesting items about the mountain is its role in a fascinating historical experiment. In 1774 an experiment was carried out at the mountain to ascertain the mean density of the earth. The experiment was complex and required a mountain which stood basically alone, as Shiehallion does.

The idea is to compute the mass of the mountain which was accomplished by suspending plumb lines on either side of the mountain. The mass of the mountain would cause the plumb lines to move slightly from the vertical since the mountain itself would have a gravitational pull that would cause the deflection to happen.

The details, techniques and math involved are complex and need not concern up here. Nevil Maskelyne and Charles Mason, both English astronomers, (whose name appears in the “Mason Dixon line” in the U.S.) were involved with the project. At the conclusion, it was decided that the Earth had a density 4.5 times that of water. The current scientific experiments show it to be 5.515, so the determination was off by less than 20%. Nonetheless, this attempt at Mt Schiehallion was the first time that the density of the Earth had been calculated.

Mount Schiehallion is not the easiest place to visit, since there is no easy public transportation to it. An automobile can make the journey from Perth, Birnam or Pitlochry in about an hour. Pitlochry is probably the closest and the drive is about ¾ of an hour. Birnam is a bit further and a drive of about an hour and a quarter would be needed from Perth.