Journey 1
Thomas Pennant
Canna
What’s the secret of Compass Hill?
Today a mere 16 people live on Canna, compared to the 220 Pennant found. A whole town has been razed,
and the legacy of the Highland Clearances (see Islay) is acutely apparent.
As well as recording his anguish at the islanders’ plight, Pennant was intrigued by their rumoured gift for ‘second sight’, and keen to solve the mystery of Compass Hill.
A previous explorer had recorded his mariner’s compass as veering from north to east, a full 90 degrees out, when standing on a high spot on Canna. Pennant tracked down the same spot, and also recorded his compass as swinging from north to west.
After a search to find the ‘red rocks’ Pennant described, Nick Crane too experiences the freak effect of Canna’s Compass Hill. The cause is iron – an extremely localised concentration of up to 10% overrides the earth’s natural magnetic field.