7 i 6 THE POPULAR SCIENCE MONTHLY. 



rejects as unverified the asserted absolute rainlessness of the deserts, 

 and in the precipitated meteoric water finds a sufficient supply for 

 the wells of the low-lying oases. With the aid of meteorology it 

 shows how one continent tends to reduce another to the condition of a 

 desert ; and, taking man into the sphere of its observations, it dis- 

 cusses the influence of the soil and the configuration of a region upon 

 the course of culture-development therein, and even upon the develop- 

 ment of peculiarities of speech. Scientific geography in this way 

 vivifies the dead superficies of our planet, and gives to the conven- 

 tional lines of a map the power of speaking a language that is under- 

 stood by the educated mind. 



The endeavor to meet the requirements of a higher geography is 

 also to be seen in the better style of our modern maps. Thus, whereas 

 in former times the seas were represented by blank spaces surround- 

 ing the land, now we have the results of soundings carefully repre- 

 sented, and the lines of equal depths, as they are more or less parallel 

 to the present contours of the coast, supply to the geographer valuable 

 data with respect to the formation of the land itself. On looking at 

 the sketch of the Mediterranean Sea, in which various depths from 

 fifty to five hundred fathoms are represented, the reader will perceive 

 far more clearly than he could from the mere contour of the coasts 

 that, not taking the Black Sea into account, the Mediterranean Sea 

 proper consists of two great basins, viz., a western basin, extending 

 from Gibraltar to Cape Bon and the southwestern extremity of Sicily, 

 and an eastern basin extending thence to the coast of Syria. The 

 shallow depth between Africa and Sicily, and especially the track of 

 the hundred-fathom line, shown in our map by a dotted curve, prove 

 that, at a time not very remote geologically, Africa and Europe were 

 much nearer to one another than they are now, and that in the still 

 remoter past the two continents were connected at this point. In 

 all probability this union existed at a period when as yet the present 

 southern shore of the eastern Mediterranean basin had not been up- 

 heaved, and the sea covered a portion of what is now the Sahara. 

 French investigators have supposed that the most recent retreat of 

 the sea was from the Syrtis Minor ; nay, that even in historic times 

 the great Algerian Chotts were directly connected with the Mediter- 

 ranean as an arm of that sea. But this hypothesis is negatived by G. 

 Stache's discovery of a stratum characterized by land and fresh-water 

 -lulls, at the base of the Quaternary formations which constitute the 

 coast of the Gulf of Gabes. 



If we take up a geological chart, e. g., the beautiful " General Map 

 of the Sedimentary Formations of Europe," by H. Habenicht, we find 

 nothing that contradicts these conclusions. Thus the Eocene forma- 

 tions, which are widely diffused over the northern extremity of Africa, 

 and especially in Tunis, occur again in the island of Sicily, while the 

 southern and the southwestern portion of that island show the most 



