There are, in fact, two rainless belts or districts, one on each side of the Equator. In the old world, the northern belt commences on the west side of Africa; includes the Sahara between 16° and 28° of latitude; and narrowing as it extends easterly, comprises on the banks of the Nile from 19° to 27°. It also embraces the low coast; and portions of the interior of Arabia; passes through Beloochistan to the base of the Himalayas, and terminates with the rainless tableland of Thibet. The southern district occurs north of the Gareep or Orange River in South Africa, and includes wide tracts in Australia, and a narrow belt in South America. Where the earth is blessed with copious showers, vegetation will abound; grass, and herb, flower, bush, and tree; "Fields of grain Will bend their tops To the numberless beating drops." To meet with the true Desert we must, therefore, direct our steps in a north-westerly course, and penetrate into _The Sahara_. M. Charles Martins, in his elaborate monograph on this remarkable region, divides it into three distinct sub-regions: the _Desert of the Table-lands_, the _Desert of Erosion_, and the _Sandy Desert_.[53] In Algeria, and in Barbary generally, the Mediterranean littoral does not come into immediate contact with the Sahara; but is separated from it by the Atlas chain. But the Atlas does not rise abruptly from the plain: on either side it ascends by a succession of rocky steps or terraces, which form the sub-region of the elevated Table-lands. Vast denuded surfaces, sprinkled with _chotts_, or salt lakes, deprived of all arborescent vegetation, traversed in summer by immense herds which feed on the plants even to their very roots, bare mountains starting abruptly from these horizontal surfaces; such is the general aspect of the landscape. The richly-varied culture of the Mediterranean littoral has disappeared, and barley is the only cereal which the husbandman relies upon for his harvest. At many points, however, the "purple vine" and "golden olive" succeed admirably, and are destined one day to clothe the nakedness of these plateaux which the free-pasturing herds and the careless Arab have stripped of their blooming verdure. Descending these rocky terraces of gray old Atlas, we enter the desert region in its first phase: the Desert of the Table-lands, or Saharan Steppe. [Illustration: LANDSCAPE IN THE ATLAS (REGION OF TABLE-LANDS).]