Letters concerning the northern coast of the County of Antrim. Containing a natural history of its basaltes: with an account of such circumstances as are worthy of notice respecting the antiquities, manners and customs of that country. The whole illustrated by an accurate map of the coast, roads, mountains, &c. In there letters is stated a plain and impartial view of the volcanic theory of the basaltes By the Rev. William Hamilton, A. M.