D. W.
There is one of these floating islands in Loch Lomond in Argyll, another in Loch Dochart in Perthshire, and another in Loch Treig in Inverness. Their origin is probably due to a mass of peat being detached from the shore, and floated out into the lake. A mass of vegetable matter, however, has sometimes risen from the bottom of the water, and assumed for a time all the appearance of an island. This has been probably due to an accumulation of gas, within or under the detached portion, produced by the decay of vegetation in extremely hot weather.
Southey, in an unpublished letter to Sir George Beaumont (10th July 1824), thus describes the Island at Derwentwater: “You will have seen by the papers that the Floating Island has made its appearance. It sank again last week, when some heavy rains had raised the lake four feet. By good fortune Professor Sedgewick happened to be in Keswick, and examined it in time. Where he probed it a thin layer of mud lies upon a bed of peat, which is six feet thick, and this rests upon a stratum of fine white clay,—the same I believe which Miss Barker found in Borrowdale when building her unlucky house. Where the gas is generated remains yet to be discovered, but when the peat is filled with this gas, it separates from the clay and becomes buoyant. There must have been a considerable convulsion when this took place, for a rent was made in the bottom of the lake, several feet in depth, and not less than fifty yards long, on each side of which the bottom rose and floated. It was a pretty sight to see the small fry exploring this new made strait and darting at the bubbles which rose as the Professor was probing the bank. The discharge of air was considerable here, when a pole was thrust down. But at some distance where the rent did not extend, the bottom had been heaved up in a slight convexity, sloping equally in an inclined plane all round: and there, when the pole was introduced, a rush like a jet followed, as it was withdrawn. The thing is the more curious, because as yet no example of it is known to have been observed in any other place.”
Another of these detached islands used to float about in Esthwaite Water, and was carried from side to side of the pool at the north end of the lake—the same pool which the swans, described in The Prelude, used to frequent. This island had a few bushes on it: but it became stranded some time ago. One of the old natives of Hawkeshead described the process of trying to float it off again, by tying ropes to the bushes on its surface,—an experiment which was unsuccessful. Compare the reference to the Floating or “Buoyant” Island of Derwentwater, and to the “mossy islet” of Esthwaite, in Wordsworth’s Guide through the District of the Lakes.—Ed.
“THE CRESCENT-MOON, THE STAR OF LOVE”
Published 1842
One of the “Evening Voluntaries.”—Ed.
The Crescent-moon, the Star of Love,
Glories of evening, as ye there are seen
With but a span of sky between—