There were formerly four castles in the island, viz. Castle Cornet, the Castle in the Marshes, Vale Castle, and the Castle of Notre Dame. Castle Cornet is situated on a rock of gneiss often approaching to granite, and in tersected by veins of quartz, trap, and felspar, curved and mixed in various ways. This rock is about a quarter of a mile from the shore, and near Port St Peter's. It is scarcely accessible but on one side. It is surrounded with an outer wall of great thickness, flanked by several machicolated towers, and the keep has been converted into casemates. Elizabeth enlarged it with a lower line of curtain and bastions ; and barracks and accommodation for a numerous garrison have since been formed. It is now defended by a considerable quantity of heavy artillery.
The Castle in the Marshes appears to be very ancient. It is encircled with a double wall of granite, and has an outer and inner ditch, and a keep in the Norman form.
The Vale Castle, which is also ancient, stands upon a commanding eminence, near St Sampson's harbour. It was once reckoned to be strong, but it has now only a surrounding wall, with flanking towers, and a portal. There arc barracks for a garrison ; and several pieces of cannon on the, ramparts, command a passage called the Russel. The castle of Notre Dame, and that of Rocquane, no longer exist.
The inhabitants are chiefly employed in agriculture, and in the cultivation of their gardens and orchards, from which great quantities of excellent cyder are made. The only manufacture is that of woollen goods. They are allowed to import 1000 tons of wool annually from England, which is made into stockings, waistcoats and breeches. Lobsters are the only fish which is exported. Guernsey was, before the establishment of the London Docks, the grand depot of all the foreign wines and brandies. Towards the bay of St Sampson's there is a fine rock of grey or black granite, which is exported in large quantities to London and Portsmouth. It is called the Guernsey or St Sampson's stone, and being hard and tough, it is admirably adapted for building and paving, as it easily breaks into square masses before the. hammer. Dr Macculloch could not obtain any physical or historical evidence that emery was a production of this island, as has been generally stated. Every part of the coast of Guern sey is fortified with strong batteries and breast works. The number of houses in St Peter's Is about 800, and the po pulation of the island about 15,000.
See Dicey's History of Guernsey ; Grose's Antiquities of England and !Vales; and Macculloch's Account of Guern sey in the Transactions of the Geological Society, vol. i. p. 7.