THE COAST 59 removed to St Mary's. The total acreage of the islands is 3560 ; and the formation is granite. This group is in fact the rubbed-down stump of the last great peak of the chain running south-west from Bodmin moors. The heights in the islands are inconsiderable, but very bold and picturesque scenery is obtained among the many islets, each of which has its special character. At St Mary's is The Longships Lighthouse a pier built in 1835-8 ; and a harbour called the Pool for small craft, while further out between the islands is a good roadstead for large vessels. The Scilly Isles were noted as a resting-place for innumerable birds, some very rare, in their annual migrations, but of late years gun-practice at sea marks has scared a good many away, and they visit the islands in far fewer numbers than formerly.