The various corps of an army drawn up in line of battle are distinguished not only by their various uniforms, but also by the distinct position assigned them in the field. This greatly helps the general to the immediate disposition of sharpshooters, infantry, or artillery, as the fate of battle may require. Most of the minerals which are the basis of our commercial and mining greatness are obtained from the Carboniferous system. The industrialist obtains them from various parts of this formation. When a new substance has presented itself, having characters very different from the ordinary rank and file of coals, clay-bands, or fire-clays, its stratigraphical position will help us to determine if it is entitled to a distinct character. If its place be distinct from those of the ordinary coals, if likewise there are indications of a different physical mode of formation, then its claim to be a new mineral will be greatly strengthened.

The lower carboniferous rocks of Scotland consist of shales and sandstones more than a thousand feet thick, termed by Mr. Maclaren the calciferous sandstone series. A freshwater limestone, equivalent to that worked at Burdie House, near Edinburgh, is the predominant member of this group. This limestone runs in an elliptical area round that city for nearly twenty-four miles, extending through Fife, Midlothian, and Linlithgowshires. Part of this series extends to the south-east of the town of Bathgate, round which is the Torbane Hill mineral basin.