204 ABOUT LAKE TCHAD. 



rassed his progress more and more ; and after a useless and pro- 

 longed struggle to escape from the quagmire, seeking in vain on the 

 horizon some mirror-like surface, he retraced his steps, dabbling in 

 the slimy water, and consoling himself with the reflection that at 

 least he had seen some traces of the " liquid element." But the 

 scene was strangely different when, in the winter of 185455, more 

 than one-half of the Ngornou was destroyed by the inundation ; and 

 to the south of that town lay a deep sea, swallowing up the whole 

 plain even to the village of Koukiya ! The lower stratum of the 

 soil, composed of limestone, appeared to have given way in the 

 preceding year, and had lowered the shore of the lake several yards ; 

 hence the inundation. But apart from this evidently exceptional 

 geological catastrophe, the character of the Tchad is clearly that of an 

 immense lagoon whose borders change every month, and of which it 

 is consequently impossible to lay down any strictly accurate map.* 



Lake Tchad lies between lat. 12 30' and 14 30' N., long. 13 

 and 15 30' S. Its length varies from two hundred to three hundred 

 miles, according to the amount of rainfall and similar circumstances ; 

 at its broadest it measures one hundred and seventy miles ; and it 

 has an elevation of eight hundred feet above the sea-level. The 

 actual margin of its waters is lined by a deep fence of papyrus and 

 tall reeds, from ten to fourteen feet high. Its islands are densely 

 peopled. Fish and water-fowl abound, and not less do crocodiles and 

 hippopotami. The lake has no outlet, but receives several rivers, of 

 which the Waube and the Shari are the most notable. 



The country watered by the Niger is also broken up by vast 

 plains which, fertile and glowing in the rainy season, are scorched 

 and withered by the summer heats. The famous port of Kabara, 

 not far from Timbuktu, is several miles from the river, and only 

 accessible for five months in the year at the epoch of the great rains. 



Beyond this belt of vegetation, this girdle of fertility, Nature 

 wears a sombre aspect the stony look of a corpse ; for the immense 

 Desert of the Sahara begins. The transition from the one region to 

 * Dr. Earth, " Travels and Discoveries in Central Africa " (London, 1857-68). 



