Page:Africa by Élisée Reclus, Volume 3.djvu/66

 falls little short of 2,500 feet above the sea. But the general axis lies much nearer the north side, where the slope is consequently far more abrupt. Here also the general aspect of nature is wilder, the headlands more rugged, the coastline more sharply outlined, without, however, anywhere developing natural havens. The whole island presents no safe refuge where shipping may safely anchor at all times.

According to Oswald Heer, Madeira emerged probably during the Quaternary epoch, to which age seem to belong the beds of fossil plants discovered on the

north side, and the prodigious masses of land shells forming steep ramparts about Cape Sam-Lourenço at the eastern extremity of the island. Marine fossils found 1,270 feet above sea-level date from the Tertiary period, and some facts are mentioned by Walker which show that the sea has receded in the Funchal district, and which seem to point at a recent upheaval of the land.

According to Ziegler, Madeira, regarded as a horizontal mass, has a mean altitude of 2,700 feet. But in its western section the central chain, here very irregular, rises to a height of over 4,000 feet. It then expands into an extensive tableland about 10 miles round, with precipitous escarpments. This is the Paul