It is of quite modern construction, and, except indirectly, has no bearing upon the water-supply of the earthwork, having been made within a few years only for the convenience of the stock kept upon the hill farms. Some special care is taken in puddling the bottom and sides to prevent leakage, and a layer of soot is usually employed to repel boring grubs or worms which would otherwise make their holes through and let the water soak into the thirsty chalk beneath. In wet weather the pond quickly fills; once full, it is afterwards kept up by the condensation of the thick, damp mists, the dew and cloud-like vapours, that even in the early mornings of the hot summer days so frequently cling about the downs. These more than supply the waste from evaporation, so that the basin may be called a dew-pond. The mists that hang about the ridges are often almost as laden with moisture as a rain-cloud itself. They deposit a thick layer of tiny bead-like drops upon the coat of the wayfarer, which seem to cling after the manner of oil. Though these hills have not the faintest pretensions to be compared with mountains, yet when the rainy clouds hang low they often strike the higher ridges, which from a distance appear blotted out entirely, and are then receiving a misty shower. Then there rise up sometimes thick masses of vapour which during the night have gathered over the brooks and water-meadows, the marshy places of the vale, and now come borne on the breeze rolling along the slopes; and, as these pass over the dew-pond, doubtless its colder water condenses that portion which draws down into the depression where it stands. In winter the vapours clinging about the clumps of beech freeze to the boughs, forming, not a rime merely, like that seen in the vale, but a kind of ice-casing, while icicles also depend underneath. Now, if a wind comes sweeping across the hill with sudden blast, these glittering appendages rattle together loudly, and there falls a hail of jagged icy fragments. When one has seen the size and quantity of these, it becomes more easy to understand the amount of water which an intangible vapour may carry with it to be condensed into the pond or congealed upon the tree.