Like a deep groove it cuts a channel up towards the hills, becoming narrower as it approaches; and the sides diminish in height, till at the neck a few rails and a gate can close it, being scarcely broader than a waggon-track. There, at the foot of the down, it ends, overlooked by a barn, the home of innumerable sparrows, whose nests are made under the eaves, everywhere their keen eyes can find an aperture large enough to squeeze into. Looking down the steep side of the coombe, near the bottom there runs along a projecting ledge, or terrace, like a natural footway. On the opposite side is another corresponding ledge, or green turf-covered terrace; these follow the windings of the valley, decreasing in width as it diminishes, and gradually disappearing. In its broadest part one of them is used as a waggon-track, for which it is admirably adapted, being firm and hard, even smoother than the bottom of the coombe itself. If it were possible to imagine the waters of a tidal river rising and ebbing up and down this hollow these ledges would form its banks. Their regular shape is certainly remarkable, and they are not confined to this one place. Such steep-sided narrow hollows are found all along the edge of this range of downs, where they slope to the larger valley which stretches out to the horizon. There are at least ten of them in a space of twelve miles, many having similar springs of water and similar terrace-like ledges, more or less perfect. Towards the other extremity of this particular coombe--where it widens before opening on the valley--the spring spreads and occupies a wider channel, beside which there is a strip of osier-bed. When at the fountain-head, and looking down the current the end of the coombe westwards away from the hills seems to open to the sky; for the ground falls rapidly, and the trees hide any trace of human habitation. The silent hills close in the rear, capped by the old fort; the silent cornfields come to the very edge above; the silent steep green walls rise on either hand, so near together that the swallows in the blue atmosphere high overhead only come into sight for a second as they shoot swiftly across. In the evening the red sun, enlarged and bulging as if partly flattened, hangs suspended, as it seems, at the very mouth of the trough-like hollow. It is natural in the silence and the solitude for thoughts of the lapse of time to arise--of the endless centuries since, by some slow geological process, this hollow was formed. Fifteen hundred years ago the men of the camp above came hither to draw water; still the spring oozes and flows, and the sun sinks at the western mouth. So too, doubtless, the sun shone into the hollow in the evening cycle upon cycle ere then.