THE MEDITERRANEAN, PHYSICAL AND HISTORICAL. 265 



what it is popularly supposed to be, a tideless sea; but it is not so in 

 reality. In many places there is a distinct rise and fall, though this is 

 more frequently due to winds and currents than to lunar attraction. At 

 Venice there is a rise of from 1 to 2 feet in spring tides, according to the 

 prevalence of winds up or down the Adriatic; but in that sea itself the 

 tides are so weak that they can hardly be recognized, except during the 

 prevalence of the Bora, our old friend Boreas^ which generally raises a 

 surcharge along the coast of Italy. In many straits and narrow arms of 

 the sea there is a periodical flux and reflux; but the only place where 

 tidal influence, properly so called, is unmistakably observed is in the 

 Lesser Syrtis, or Gulf of Gabes. There the tide runs at the rate of 2 

 or 3 knots an hour, and the rise and fall varies from 3 to 8 feet. It is 

 most marked and regular at Djerba, the Homeric island of the Lotophagi. 

 One must be careful in landing there in a boat, so as not to be left high 

 and dry a mile or two from the shore. Perhaps the companions of 

 Ulysses were caught by the receding tide, and it was not only a banquet 

 of dates, the "honey-sweet fruit of the Lotus," or the potent wine which 

 is made from it, which made them "forgetful of their homeward way." 



The Gulf of Gabes naturally calls to mind the proposals which were 

 made a few years ago for inundating the Sahara, and so restoring to the 

 Atlantic region the insular condition which it is alleged to have had in 

 prehistoric times. I will not allude to the English project for introduc- 

 ing the waters of the Atlantic from the west coast of Africa. That does 

 not belong to my subject. The French scheme advocated by Com- 

 mandant Roudaire, and supported by M. de Lesseps, was quite as vis- 

 ionary and imi)racticable. 



To the south of Algeria and Tunis there exists a great depression, 

 stretching westward from the Gulf of Gabes to a distance of about 235 

 miles, in which are several chotts or salt lakes, sometimes only marshes, 

 and in many places covered with a saline crust strong enough to bear the 

 passage of camels. Commandant Eoudaire proposed to cut through the 

 isthmuses which separated the various chotts, and so prepare their basins 

 to receive the waters of the Mediterranean. This done, he intended to 

 introduce the sea by a canal, which should have a depth of 1 metre 

 below low-water level. 



This scheme was based on the assumption that the basin of the chotts 

 has been an inland sea within historic times; that, little by little, owing 

 to the difference between the quantity of wat«r which entered and the 

 amount of evaporation and absorption, this interior sea had disapi>eared, 

 leaving the chotts as an evidence of the former condition of things; that, 

 in fact, this was none other than the celebrated Lake Triton, the posi- 

 tion of which has always been a puzzle to geographers. 



This theory however is untenable. The isthmus of Gabes is not a 

 mere sand bank. There is a band of rock between the sea and the basin 

 of the chotts, through which the former never could have penetrated in 

 modern times. It is much more probable that Lake Triton was the 



