SCILLY ISLES, group of small islands, off Cornwall, Eng land, 25 m. W. by S. of Land's End. They form an outlying member of the series of granite masses of Cornwall and contain a few metalliferous veins. The origin of their name has never been authoritatively settled. The islands are wild and picturesque, with sheer cliffs and many large caves hollowed out by the Atlantic. Owing to the reefs and shoals by which these shores are surrounded, navigation becomes perilous in rough weather. In 1707 Sir Cloudesley Shovel perished here and a local proverb tells that for every man who dies a natural death on the islands the sea takes nine. On an outlying rock to the south-west is Bishop Light 30" N., 6° 27' W.), constructed with infinite difficulty in 1858, and rebuilt 3o years later, and other lighthouses are on Round island and Penninis head (St. Mary's).
The islands are composed of granite, most of which is coarse and porphyritic, but the centre of the mass is finer and non porphyritic. The finer granite occurs on the north-west side of St. Mary's, the southern part of Tresco, Bryher and Samson and the north-west side of Annet. Elvans (dykes) of quartz-por phyry are found in the granite. On the north-east end of White island a fragment of the altered killas (shale), which once cov ered the whole area, is still visible. A gravel deposit with chalk flints and Greensand cherts which caps some of the higher ground on St. Mary's may possibly be of Eocene age. Raised beach, blown sand, fragmental granitic waste and an iron-cemented glacial deposit are found resting upon the granite.
The climate of the islands is unusually mild, snow being rarely seen, and the range of temperature being from 46° to 58° F. Fuchsias, geraniums and myrtles attain an immense size, and aloes, cactus and prickly pear flourish in the open. The gardens of the governor on Tresco island are quite subtropical in char acter, and, therefore, unique in the British isles. Great flocks of sea-birds haunt the remoter parts, and on some of the islands there are deer. Some of the rarer land-birds occasionally visit the islands, such as the golden oriole.
The islands are served by steamers from Penzance, and tele phone and telegraph communication is established with the main land. The raising of early asparagus, spring vegetables and flow ers is the principal industry. There is also a small coasting trade; and fishing is carried on, lobsters being sent to London.
The true islands number about 4o, with total area of 4,041 ac. ; but only five islands are inhabited—St. Mary's, Tresco, St.
Martin's, St. Agnes and Bryher. The total population in 1931 was 1,732. Hugh Town in St. Mary's is the capital, occupying a sandy peninsula crowned by the height known as the Garrison, with Star castle, dating from the days of Elizabeth. The town possesses a harbour, and a roadstead where large vessels can lie at anchor. Governed by a county council, they are part of the St. Ives par liamentary division, Cornwall.
On Tresco there are ruins of an abbey, and of two fortifications called Oliver Cromwell's tower and King Charles's tower. The church of St. Nicholas was built in 1882. Numerous rude pillars and circles of stones are to be noticed ; and barrows are common, the most remarkable of these prehistoric remains being a barrow on the Isle of Samson, 58 ft. in girth, and containing a very perfect "kistvaen," or sepulchral chamber of stone.
It is not until the reign of Henry I. that we have written evi dence concerning these isles. The king gave all the churches of Scilly and the land to the abbot and church of Tavistock. In ii8o the bishop of Exeter confirmed a grant by Richard de Wicha. Secular priests were temporally substituted for regulars by the abbot of Tavistock in 1345. The family of Blanchminster (de Albo Monasterio), at the beginning of the 14th century, held of the earldom of Cornwall lands in Scilly at a yearly service of 6s. 8d. or 600 puffins. The Blanchminsters resisted and impris oned the coroner of Cornwall and in 1319 were granted a coroner of their own. In 1345 they are found petitioning the king against an invasion of the king's Welsh troops, who, being becalmed at Scilly, had carried away everything. In 1547 Silvester Danvers, as representing the Blanchminsters, sold his moiety of Scilly to Sir Thomas Seymour, by whose attainder in 1549 this and prob ably the other moiety fell to the Crown. The suppression of the religious houses had already placed church land and revenues at the king's disposal. During the Civil Wars, Hugh Town in 1645 gave shelter to Prince Charles, until his escape to Jersey. In 1649 the islands were occupied by a royalist, Sir Richard Gren ville, who swept the surrounding seas for two years, before Ad miral Blake and Sir John Ayscue forced him to surrender. In ancient times a haunt of pirates, the islands were afterwards no torious for smuggling. In 1687 the whole of Scilly was granted to Sidney Godolphin for 89 years from the expiration of the lease for 5o years granted to Francis Godolphin in 1636 by Charles I. In 1831 Augustus Smith succeeded the Godolphins as lessee.