SCILLY ISLANDS, a group of islands about 30 miles W. by S. from the Land's Eud in Cornwall, lying between 49° 51' and 50° N. lat., 6° 11' and 6° 30' W. long. The aggregate area is 3560 acres. The population in 1851 was 2627. The group forms one parish, in the arcbdeaconry of Cornwall and diocese of Exeter.
The ancient condition of these islands has been the subject of much discussion. That at some remote period, antecedent to authentic history, they may have been united to the main, and have boon sepa rated from it by the incroachment of the sea, is not improbable. The space between them and the mainland is occupied by softer rocks, if we may judge from an insulated limestone rock, called the 'Wolf,' and hard as they are, they are themselves diminishing in size. At present there are more than 140 islands, but only six of them are inhabited. These are—St. Mary's, on the east side of the group; Tresco, north-west; St. Martin's, north-east; St. Agnes, south; Bryher, north-west ; and Sampson, west.
The islands form a compact group, of about 30 miles in circum ference, surrounded by a deep sea, from which they rise for the most part abruptly, with rugged sides. Between the islands the depth of the sea is ranch less; and in several parts extensive flats, some of them dry at low water, extend from island to island. The islands and rocks consist almost entirely of granite, but there are in St. Mary's Island some beds of porphyry and some of chlorite containing pyrites. Detached stones of gypsum and alabaster are found in Tresco, St. Martin's, and St. Mary's. The granite is very liable to decomposition, and presents some interesting geological phenomena. The shores are covered in some parts by a coarse sand, the detritus of granite, occa sionally agglutinated into a kind of sandstone ; in other parts by a fine shining white sand. The climate is milder and more equable than that of Cornwall, but the islands are subject to dense fogs and to sndden and violent storms. Few days of perfect calm occur in the conree of the year, and during the greater part of it the wind blows from various points between north-west and south-west.
St. Mary's, population 1668 in 1851, is the most important island. It consists of two portions, the smaller of which, 'called 'the Hugh,' is united to the other part by a low sandy isthmus, on which stands Hugh Town, the capital of the group. The shore is generally steep, and there are some small inlets or coves, besides St. Mary's Pool, on the north side, and Port Creme on the south side of the isthmus of Hugh Town. The island is about 8 miles in circumference. The
soil is generally good, and produces excellent crops of corn and pota toes. Hugh Town consists of a principal street, very crooked, and of several lanes, alleys, and courts. A handsome church in the gothio style, with a tower, was completed in 1838, at a cost of 1500L The Wesleyan Methodists have a place of worship. Most kinds of handi craft are exercised in the island. A pier 430 feet long and 20 feet broad, extends into St. Mary's Pool. A small building, called the court-house, is'used by the council appointed by the proprietor of the islands; beneath it are a small prison and a butcher's stall, which receives the name of the market-house. Tho other principal buildiugs are the steward's house and the post-office. About a mile from Hugh Town, eastward, is the hamlet of Old Town, once the principal place in the island, and still containing about 200 inhabitants, chiefly fishermen. Small cottages are dispersed over the island, occasionally grouped three or four together ; one little group is called London, another Bristol. The old church, with the graveyard, is near Old Town. The Hugh is a steep hill rising about 110 feet above the level of the sea ; it is fortified by lines having a circuit of more than a mile, with 18 bastions or batteries, and including a small fort and barracks for the officers and troops. There aro two schools, supported by the Christian Knowledge Society, and another school with a small endowment Treace, population 416 in 1851, the island next in importance, is inhabited chiefly by pilots and fishermen. Most of the houses are on the north-east side, near the beach, opposite a harbour called Old Grinsey harbour, and form a village called Dolphin Town. In the south part of the island is a fine sheet of fresh water, half a mile long and a furlong broad. Near this lake are the remains of a religious house. The Abbey, a mansion recently erected by Augustus Smith, Esq., the lessee of the Mends, stands also near the lake. Treace has a small church, a Wesleyan meeting-house, a mission-house of the Society for the Promotion of Christian Knowledge, and a small unoc cupied fort or block-house. There are a stone tower called Oliver's Castle, now deserted, and the ruins of a fortress called King Charles's Castle. On the north side of the island is a remarkable subterranean passage called Piper's Hole. The Society for the Promotion of Christian Knowledge supports here a clergyman and a day-school.