Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/262



The outline of these hills, is characterized by gradual and successive swellings and depressions of the ground; they also offer natural scoops or semi-circular excavations on their acclivities. Though covered with a short grass, they may be called naked, being entirely destitute of timber.

They rise to a greater absolute elevation than the other beds by which they are accompanied; so that even at a distance, we may safely conclude the highest bare hills to be chalk.

This rock is harder than most of those with which it is associated, and in consequence wherever it appears on the coast, the sea-water is in such places, more transparent, and generally of a greater depth, on account of the cliffs being cut off more abruptly.

The cliffs of chalk assume often the shape of recesses or semicircular bays, the outline of which is well defined: such is Freshwater Bay, Lulworth Cove, the Bay of Weymouth, &c.

In the Isle of Wight, the chalk hills, as far as I could ascertain form a belt across the middle of the island, the greatest breadth of which may be five or six miles. As this belt proceeds westward, it contracts gradually to a point of land deeply indented on the north by Alum Bay, and on the south by Freshwater Bay. On that projecting tongue of land called High Down stands the signal post, the light house further on to the west, and the Needles lower down. I found by the barometer the elevation of the signal house to be 430 feet above the level of the sea; that of the light house 379; and of the furthest and most western part of the cliffs, above the Needles, 189 feet.