Falling in Love, Grant Allen [best ebook reader under 100 TXT] 📗

True cactuses (in the native state) are confined to America; but the unhappy naturalist who ventures to say so in mixed society is sure to get sat upon (without due cause) by numberless people who have seen 'the cactus' wild all the world over. For one thing, the prickly pear and a few other common American species, have been naturalised and run wild throughout North Africa, the Mediterranean shores, and a great part of India, Arabia, and Persia. But what is more interesting and more confusing still, other desert plants which are not cactuses, living in South Africa, Sind, Rajputana, and elsewhere unspecified, have been driven by the nature of their circumstances and the dryness of the soil to adopt precisely the same tactics, and therefore unconsciously to mimic or imitate the cactus tribe in the minutest details of their personal appearance. Most of these fallacious pseudo-cactuses are really spurges or euphorbias by family. They resemble the true Mexican type in externals only; that is to say, their stems are thick, jointed, and leaf-like, and they grow with clumsy and awkward angularity; but in the flower, fruit, seed, and in short in all structural peculiarities whatsoever, they differ utterly from the genuine cactus, and closely resemble all their spurge relations. Adaptive likenesses of this sort, due to mere stress of local conditions, have no more weight as indications of real relationship than the wings of the bat or the nippers of the seal, which don't make the one into a skylark, or the other into a mackerel.

In Sahara, on the other hand, the prevailing type of vegetation (wherever there is any) belongs to the kind playfully described by Sir Lambert Playfair as 'salsolaceous,' that is to say, in plainer English, it consists of plants like the glass-wort and the kali-weed, which are commonly burnt to make soda. These fleshy weeds resemble the cactuses in being succulent and thick-skinned but they differ from them in their curious ability to live upon very salt and soda-laden water. All through the great African desert region, in fact, most of the water is more or less brackish; 'bitter lakes' are common, and gypsum often covers the ground over immense areas. These districts occupy the beds of vast ancient lakes, now almost dry, of which the existing chotts, or very salt pools, are the last shrunken and evanescent relics.

And this point about the water brings me at last to a cardinal fact in the constitution of deserts which is almost always utterly misconceived in Europe. Most people at home picture the desert to themselves as wholly dead, flat, and sandy. To talk about the fauna and flora of Sahara sounds in their ears like self-contradictory nonsense. But, as a matter of fact, that uniform and lifeless desert of the popular fancy exists only in those sister arts that George II.—good, practical man—so heartily despised, 'boetry and bainting.' The desert of real life, though less impressive, is far more varied. It has its ups and downs, its hills and valleys. It has its sandy plains and its rocky ridges. It has its lakes and ponds, and even its rivers. It has its plants and animals, its oases and palm-groves. In short, like everything else on earth, it's a good deal more complex than people imagine.

One may take Sahara as a very good example of the actual desert of physical geography, in contradistinction to the level and lifeless desert that stretches like the sea over illimitable spaces in verse or canvas. And here, I fear, I am going to dispel another common and cherished illusion. It is my fate to be an iconoclast, and perhaps long practice has made me rather like the trade than otherwise. A popular belief exists all over Europe that the late M. Roudaire—that De Lesseps who never quite 'came off'—proposed to cut a canal from the Mediterranean into the heart of Africa, which was intended, in the stereotyped phrase of journalism, to 'flood Sahara,' and convert the desert into an inland sea. He might almost as well have talked of cutting a canal from Brighton to the Devil's Dyke and 'submerging England,' as the devil wished to do in the old legend. As a matter of fact, good, practical M. Roudaire, sound engineer that he was, never even dreamt of anything so chimerical. What he did really propose was something far milder and simpler in its way, but, as his scheme has given rise to the absurd notion that Sahara as a whole lies below sea-level, it may be worth while briefly to explain what it was he really thought of doing.

Some sixty miles south of Biskra, the most fashionable resort in the Algerian Sahara, there is a deep depression two hundred and fifty miles long, partly occupied by three salt lakes of the kind so common over the whole dried-up Saharan area. These three lakes, shrunken remnants of much larger sheets, lie below the level of the Mediterranean, but they are separated from it, and from one another, by upland ranges which rise considerably above the sea line. What M. Roudaire proposed to do was to cut canals through these three barriers, and flood the basins of the salt lakes. The result would have been, not as is commonly said to submerge Sahara, nor even to form anything worth seriously describing as 'an inland sea,' but to substitute three larger salt lakes for the existing three smaller ones. The area so flooded, however, would bear to the whole area of Sahara something like the same proportion that Windsor Park bears to the entire surface of England. This is the true truth about that stupendous undertaking, which is to create a new Mediterranean in the midst of the Dark Continent, and to modify the climate of Northern Europe to something like the condition of the Glacial Epoch. A new Dead Sea would be much nearer the mark, and the only way Northern Europe would feel the change, if it felt it at all, would be in a slight fall in the price of dates in the wholesale market.

No, Sahara as a whole is not below sea-level; it is not the dry bed of a recent ocean; and it is not as flat as the proverbial pancake all over. Part of it, indeed, is very mountainous, and all of it is more or less varied in level. The Upper Sahara consists of a rocky plateau, rising at times into considerable peaks; the Lower, to which it descends by a steep slope, is 'a vast depression of clay and sand,' but still for the most part standing high above sea-level. No portion of the Upper Sahara is less than 1,300 feet high—a good deal higher than Dartmoor or Derbyshire. Most of the Lower reaches from two to three hundred feet—quite as elevated as Essex or Leicester. The few spots below sea-level consist of the beds of ancient lakes, now much shrunk by evaporation, owing to the present rainless condition of the country; the soil around these is deep in gypsum, and the water itself is considerably salter than the sea. That, however, is always the case with freshwater lakes in their last dotage, as American geologists have amply proved in the case of the Great Salt Lake of Utah. Moving sand undoubtedly covers a large space in both divisions of the desert, but according to Sir Lambert Playfair, our best modern authority on the subject, it occupies not more than one-third part of the entire Algerian Sahara. Elsewhere rock, clay, and muddy lake are the prevailing features, interspersed with not infrequent date-groves and villages, the product of artesian wells, or excavated spaces, or river oases. Even Sahara, in short, to give it its due, is not by any means so black as it's painted.