Most of the hills and crags in the Carboniferous area are volcanic, and many of them - such as the castle rocks of Edinburgh and Stirling, Binny Craig in Linlithgowshire, North Berwick Law and the Bass Rock - mark the sites of actual events of eruption.
Linlithgowshire yields nearly three-fourths of the total output, Midlothian produces nearly one-fourth, a small quantity is obtained from Lanarkshire, and there is an infinitesimal supply from Sutherland.
From 180 9 onwards Stewart lived mainly at Kinneil House, Linlithgowshire, which was placed at his disposal by the duke of Hamilton.