124 The National Geographic Magazine 



Early in April the three French 

 parties met on the Shari, the principal 

 tributary to Lake Tchad. The scien- 

 tific mission of Foureau was now ended. 

 His work includes a survey of 3,655 

 miles, from Ouargla, in Algiers, to 

 Bangui, on the Ubangi, in French 

 Kongo, of which 1,218 miles had never 

 before been traversed by a European. 

 This survey is based on 510 astronom- 

 ical positions. Foureau has also de- 

 termined the boundary between the 

 sedimentary formations of Northern 

 Sahara and the crystalline massifs -oi 

 Central Sahara, and collected, in addi- 

 tion, many botanical, zoological, ethno- 

 graphical, and archaeological specimens. 

 In the Sahara archaeolog}' is represented 

 by many figures sculptured in rocks 

 and by very curious ancient tombs. 



The two other expeditions, under 

 Gentil and Joalland, have obtained 

 equalty important scientific results. 

 During the years 1899 and 1900 M. 

 Gentil, commissioner of the Territories 

 of Tchad, and his colleagues, made sur- 

 veys of 4,600 miles included between 

 the sources of the Ubangi, the Niger, 

 and Tchad. The first of these regions 

 is quite well populated, there being 

 about 15 inhabitants to the square mile. 

 M. Gentil in a boat steamed over a 

 large part of Lake Tchad, and found 

 that this great lake is navigable at all 

 seasons of the 3'ear. The peoples living 

 here are extremely interesting. At 

 Zincler feudal institutions exist such as 

 were in France at the beginning of the 

 Middle Ages. The people are thus ten 

 centuries behind the world. 



After their union, the three French 

 troops, about 700 men strong, on April 

 22, 1900, attacked the army of the 

 Rabah. He had 7,000 men, of whom 

 2,000 were armed with rapid-fire guns; 

 but the little French company put them 

 to complete rout. The country of Tchad 

 was thus acquired. 



Besides these three principal expedi- 

 tions of Marchand, Foureau, and Gen- 



M. Gentil. 



til, many other parties were exploring 

 the different French Colonies of Africa. 

 During December, 1899, to February, 

 1900, M. Flamand was exploring the 

 oasis of Tibikelt, south of Algeria, 

 where the phenomenon of eolian erosion 

 is taking place. Flamand was attacked 

 b}' the Arabs. The scientist immedi- 

 atety became a general, and with his 

 100 Arabs put his assailants to flight. 

 By this victory France acquired the 

 hitherto independent oases of Tidikelt, 

 the possession of which will insure con- 

 trol of the tribes of the Sahara. 



Less fortunate was the expedition of 

 Blanchet in the region of Adrar, that 

 part of the Sahara which is north of 

 Senegal. The party was captured by 

 the Moors, and remained in captivity 

 for two months. When set free they 

 were compelled to return. 



In French West Africa three natural- 

 ists, Chevalier, Cligny, and Rambaud, 



