Schiehallion - "weighing the world"

We were up in Aberfeldy this afternoon and I suggested we go in search of
Schiehallion, which proved to be challenging due to the rain and the mountains isolation.

This is a very special Scottish mountain though it may look like yet another misty peak on a dreich summer day.

For Schiehallion (3,547ft), a cone shaped mountain has a unique place in scientific history because it was used in an 18th-century experiment to "weigh the world."


In order to do this the geo-scientists needed a large symmetrical cone shaped mountain clear of others and this one in the heart of the Perthshire Mountains fulfilled the necessary criteria.

The deflection of a pendulum by the mass of the mountain provided an estimate of the mean density of the earth from which its mass could be deduced.

Mark Reeves blog gives a brilliant account of this experiment.


The experiment, repeated in 2007 using all the latest computer technology, proved the original one to be accurate.

Well, this made quite a different Sunday afternoon jaunt.