ABSTRACT
This chapter considers the more direct part which worms take in the denudation of the land. From a very remote period and in many countries, land has been ploughed, so that convex beds, called crowns or ridges, usually about 8 feet across and separated by furrows, have been thrown up. The furrows are directed so as to carry off the surface water. In attempts to ascertain how long a time these crowns and furrows last, when ploughed land has been converted into pasture, obstacles of many kinds were encountered. In many districts where the land is nearly level, a bed of several feet in thickness of red clay full of unworn flints overlies the Upper Chalk. This overlying matter, the surface of which has been converted into mould, consists of the undissolved residue from the Chalk. St Catherine's Hill, near Winchester, is 327 feet in height, and consists of a steep cone of Chalk about of a mile in diameter.
