Now he crosses the Bidassoa ... the whole world changes! At once his train plunges into interminable Pyrenees, and ere it clears these, he has ascended to a permanent highland level--a tawny treeless steppe that averages 2000-feet altitude, and sometimes approaches 3000, traversed by range after range of rugged mountains that arise all around him to four, five, or six thousand feet. Railways, moreover, avoid mountains (so far as they can). Our traveller, therefore, must bear in mind that what he actually sees is but the mildest and tamest version of Spanish sierras. There are bits here and there that he may have thought anything but tame--only tame by comparison with those grander scenes to which we propose guiding him.
For the next 500 miles he never quits that austere highland altitude nor ever quite loses sight of jagged peaks that pierce the skies--peaks of that hoary cinder-grey that shows up almost white against an azure background. Never does he descend till, after leaving behind him three kingdoms--Arragon, Navarre, and Castile--his train plunges through the Sierra Moréna, down the gorges of Despeñaperros, and at length on the third day enters upon the smiling lowlands of Andalucia. Here the aneroid rises once more to rational readings, and fertile _vegas_ spread away to the horizon. But our traveller is not even now quite clear of mountains. Whether he be booked to Malaga or to Algeciras, he will presently find himself enveloped once more amidst some fairly stupendous rocks--the Gaëtánes or Serranía de Ronda respectively.
Spain is, in fact, largely an elevated table-land, 400 miles square, and traversed by four main mountain-ranges, all (like her great rivers) running east and west. The only considerable areas of lowland are found in Andalucia and Valencia.
Naturally such physical features result in marked variations of climate and scene, which in turn react upon their productions and denizens, whether human or of savage breed. We take three examples.
[Illustration: TYPES OF SPANISH BIRD-LIFE
Whose home is in the wildest Sierras--a weird dragon-like bird-form; expanse, 9 feet.
[Formerly reputed to carry off _babies_ to its eyrie.]]
The central table-lands, subject all summer to solar rays that burn, in winter shelterless from biting blasts off snow-clad sierras, present precisely that landscape of desperate desolation that always results from a maximum of sunshine combined with a minimum of rainfall. A desiccated downland, khaki-colour or calcareous by turn, but bare (save for a few weeks in spring) of green thing, naked of bush or shrub, innocent even of grass. Not a tree grows so far as eye can reach, not a watercourse but is stone-dry and leaves the impress that it has been so since time began. Oh, it is an unlovely landscape, that central plateau. 'Twere ungrateful, nevertheless (and unjust too), to forget that here we are journeying in a glory of atmosphere, brilliant in aggressive radiance that annihilates distance and revels in space. Though patches of vine-growth be lost in the monotony of tawny expanse, mud-built hamlet and village church indistinguishable amidst a universal khaki, yet this is, in truth, a kingdom of the sun. The great bustard maintains a foothold on these arid uplands, but the fauna is best exemplified by the desert-loving sand-grouse (_Pterocles arenarius_).