There is another such a pond half a mile or more from the earthwork in another direction, but also on a level, making two upon this high and exposed down. Many others are scattered about--they have become more numerous of late years. Several are situate on the lower plateau, which is also dry enough. Toiling over the endless hills in the summer heats, I have often been driven by necessity of thirst to taste a little of the water contained in them, though well knowing the inevitable result. The water has a dead flavour: it is not stagnant in the sense of impurity, but dead, even when quite clear. In a few moments after tasting it, the mouth dries, with a harsh unpleasant feeling as if some impalpable dusty particles had got into the substance of the tongue. This is caused probably by suspended chalk, of which it tastes; for assuaging thirst, therefore, it is worse than useless in summer: very different is the exquisitely limpid cool liquid which bubbles out in the narrow coombes far below. The indirect bearing of the phenomena of these dew-ponds upon the water-supply of the ancient fort is found in the evidence they supply that under different conditions the deposit of moisture here might have been very much larger. The ice formed upon the branches of the beech trees in winter proves that water is often present in the atmosphere in large quantities; all it requires is something to precipitate it. Therefore, if these hills were once clothed with forest, as previously suggested, it appears possible that the primitive inhabitants, after all, may have carried on their agriculture with less difficulty, and have been able to store up water in their camps with greater ease, than would be the case at present. This may explain the traces of primeval cultivation to be seen here on the barest bleakest, and most unpromising hillsides. Such traces may be discovered at intervals all along the slope, on the summit, and near the foot of the down at the rear of the entrenchment. It is easy to pass almost over them without observing the nearly obliterated marks--the faint lines left on the surface by the implements of men in the days when the first Caesar was yet a living memory. These marks are like some of the little used paths which traverse the hills: if you look along way in front you can see them tolerably distinctly, but under your feet they are invisible, the turf being only so slightly worn by wayfarers. So, to find the signs of ancient fields, look for them from a distance as you approach along the slope; then you will see squares and parallelograms dimly defined upon the sward by slightly raised and narrow banks, green with the grass that has grown over them for so many centuries.