Topographical Dictionary of Scotland, Samuel Lewis - 1851
BUTE-ISLE-OF, an island, in the county of Bute; comprising the parishes of North Bute, Kingarth, and Rothesay, and containing 8078 inhabitants. It is in the Firth of Clyde, and separated from the district of Cowal (of Argyll), by a narrow channel. Its length is eighteen, and its breadth between four and five, miles. The northern parts are rocky and barren, but the southern extremity is more fertile, well cultivated and inclosed, and in some places finely wooded; and it is said that no part of Scotland has made more rapid progress in agriculture than this island, within the last twenty or thirty years. The climate is remarkably mild, especially in winter and spring, and during these seasons the isle is much resorted to by invalids. The coast is rocky, but is indented with several safe harbours, in which a number of small craft are fitted out for the herring-fishery, which is the principal occupation of the male inhabitants; the chief port is Rothesay. The annual value of real property in the island is £17,777. Bute contains several remains of antiquity; in particular, near Rothesay are the ruins of an ancient castle, with a fort, barracks, and drawbridge, once a residence of the kings of Scotland. There are some Danish towers, and fragments of fortifications on some of the hill-tops.