Nor must I forget the extraordinary lovely atmospheric effects, noticed also by Gilpin,[7] as seen, under certain conditions, from the Barton Cliffs on the Isle of Wight and the Needles. Far out at sea will rise a low white fog-bank gradually stealing to the land, enveloping some stray ship in its folds, and then by degrees encircling the Island, whilst the chalk cliffs melt into clouds. On it still steals with its thick mist, quenching the Needles Light which has been lit, till the whole island is capped with fog, and neither sea nor sky is seen,—nothing but a dense haze blotting everything. Then suddenly the wind lifts the great cloud westward, and its black curtains drop away, revealing a sky of the deepest blue, barred with lines of light: and the whole bay suddenly shines out clear and glittering, the Island cliffs flashing with opal and emerald, and the ship once more glides out safe from the darkness. A few words, too, must be said about the two principal tree-forms which now make the Forest. The oaks here do not grow so high or so large as in many other parts of England, but they are far finer in their outlines, hanging in the distance as if rather suspended in the air than growing from the earth, but nearer, as especially at Bramble Hill, twisting their long arms, and interlacing each other into a thick roof. Now and then they take to straggling ways, running out, as with the famous Knyghtwood Oak, into mere awkward forks. The most striking are not, perhaps, so much those in their prime, as the old ruined trees at Boldrewood, their bark furrowed with age, their timber quite decayed, now only braced together by the clamps of ivy to which they once gave support and strength.[8] The beeches are even finer, and more characteristic, though here and there a tree sometimes resembles the oaks, as if with long living amongst them, it had learnt to grow like them. The finest beech-wood is that of Mark Ash. There you may see true beech-forms, the boles spangled with silver scales of lichen, and the roots—more fangs than roots—grasping the earth, feathered with the soft green down of moss. But not in individual trees lies the beauty of the Forest, but in the masses of wood. There, in the long aisles, settles that depth of shade which no pencil can give, and that colouring which no canvas can retain, as the sunlight pierces through the green web of leaves, flinging, as it sets, a crown of gold round each tree-trunk.