Their contours depend, of course, upon the chalk of which they are built. This lies in regular layers five, six, and sometimes eight hundred feet deep from their summits to the level of the plain beneath them. It is weathered into rounded shapes that have no peaks and no precipices, or at least no precipices save those which man has deliberately created, where he has dug straight out of their sides for chalk, or where they meet the sea and are washed into perpendicular cliffs. These rounded lines of theirs against the sky, when one is travelling along them, seem in some way to add to their loneliness, and that loneliness is among the most striking of their features. They have never been built upon; it is to be believed (and profoundly to be hoped) they never will be built upon. The depth to which wells have to be sunk before water can be found is so great as to check any experiment of this kind. There is in the whole skyline, from Petersfield right to Beachy Head, not a single human habitation to break the noble aspect of these hills against the sky save one offensive shed, or what not, just north of Brighton where, it may be presumed, the economic powers of vulgarism are too strong even for the Downs. Cultivation is also very rare upon them. They are covered with a short, dense, and very sweet turf suited to the famous flocks of sheep which browse upon them, and of little value for any other agricultural purpose than the pasturage thus afforded. Those who best know the Downs and have lived among them all their lives can testify how, for a whole day’s march, one may never meet a man’s face; or if one meets it, it will be the face of some shepherd who may be standing lonely with his dog beside him upon the flank of the green hill and with his flock scattered all around. The isolation of these summits is the more remarkable from the pressure of population which is growing so rapidly to the south of them, and which is beginning to threaten the Weald to their north. But no modern change seems to affect the character of these lonely stretches of grass, and it may be noted with satisfaction that, when those ignorant of the nature of Sussex attempt to violate the security of the Downs, that experiment of theirs is commonly attended with misfortune. [Illustration: COLD WALTHAM] [Sidenote: THE SUSSEX RIVERS] Thus an open space of park-land beyond Madehurst invited the eye of a very wealthy man (presumably from the north) somewhat more than a century ago. He had not, indeed, the folly to build upon the crest of the hills, but he built not far from their summits for the pleasure that the view afforded him. The house was large and pretentious. To this day it depends for its water upon chance rains, and in the drought it pays for water as one may have to do for any other valuable thing.