It was whilst reading Bill Bryson's book, ‘A Short History of Nearly Everything’ that I stumbled across what was to me one of the most astounding ‘facts’ that I can remember reading about, – the invention of 'contour lines' as a by product of an experiment to weigh the earth.

In 1772 the Royal Society dispatched a surveyor to choose a mountain for an experiment to calculate the 'mass' of the earth. The shape was to be a steep sided cone or wedge with its ridge running west to east with steep faces north and south. It had to be standing in the landscape with low land on either side.

Neville Maskelyne – the Royal Astronomer – was funded by George III to conduct an experiment from two observatories built into the side of the North and South faces of the chosen mountain, Schiehallion. Detailed knowledge of the 3D form of the mountain was needed. A surveyor and mathematician, Dr. Charles Hutton was sent to Schiehallion for the next two seasons – the survey being delayed by bad weather. Dr. Hutton FRS., presented the computations in the form of lines joining all his measurements; he had invented contour lines and the mapping system we all use today.

Maskelyne's observations meant that he could estimate the volume of the mountain, the mass of the earth and then arrive at the calculation for the mass of the sun and other planets along with their orbits whilst proving Newton's theories of gravitational mass. All this and contour lines to boot!

I decided to make a drawing and painting 'Pilgrimage' to the mountain. This was to take me back to an area where I started to show an interest in man's interaction with the natural environment and also where I made my first serious drawings and paintings of the landscape at the age of 13.

As part of the further reaches of the Roman Empire Ptolemy mentioned Schiehallion in his 'Geography'. Being also known by the Caledonians as the "Fairy Mountain", it is obviously important in myth, science and cartography. Curious!