GEOGRAPHICAL PROGRESS AND DISCOVERY. 



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as they were come from a powerful kingdom 

 far away, whose monarch had sent to him 

 magnificent presents, of which they were the 

 bearers. They entered the dominions of the 

 Sultan of Wadai in November; he declared 

 that he would be responsible for their safety, 

 and sent his son and his brother to meet them. 



Wadai, which has never been examined at 

 ease by any European traveler before, includes 

 the states of Baghirmi and Dar Ranga in the 

 south, extending on the north to the edge of 

 the desert. Its western boundary is the Borneo 

 frontier, and its eastern an indefinite line 

 through a district inhabited by Kanem tribes. 

 The chief products and exports of Wadai are 

 ivory and ostrich-feathers. The country is 

 rich in camels and horses. The western por- 

 tions, however, are sterile and waterless. 



After crossing Wadai they traversed Bag- 

 hirmi, Borneo, and Sokoto, visiting Lake Tchad. 

 From the city of Kano-Nupe they crossed to 

 the Niger, and descended the river to the Gulf 

 of Guinea. This journey cost the young trav- 

 eler Manteucci his life. He had already dis- 

 tinguished himself on perilous expeditions in 

 the Soodan. After his arrival in London he 

 died of a wasting African fever. 



Before the successful and courageous accom- 

 plishment of Dr. Lenz's expedition from Mo- 

 rocco to Timbuctoo no scientifically trained 

 explorer had ever traversed the vast region ly- 

 ing between Earth's route through Rhat and 

 Air and the Atlantic. The only knowledge 

 we possessed of the whole western half of the 

 Sahara was derived from the itineraries of a 

 number of uninstructed travelers. Dr. Lenz 

 set out on his arduous journey from Tangier 

 in November, 1879, and, notwithstanding many 

 delays and trying difficulties, reached Timbuc- 

 too in July, 1880. He made his way to the 

 coast from there by way of the Senegal, arriv- 

 ing at St. Louis in the following November. 

 The adventures which befell him at the outset 

 of his journey are referred to in the " Annual 

 Cyclopaedia " for 1880. He did not leave the 

 city of Morocco till March 6th. In order to 

 travel more safely, he assumed the character of 

 a Turkish physician, and was accompanied by 

 Sidi Hadj All, a relative of the famous Abd el 

 Kader, whose presence afforded him security 

 among the fanatical robber bands of Howara 

 Arabs who scour the country on the farther 

 side of the Atlas Mountains up to the very 

 gates of Terodant. The Atlas range is com- 

 posed of three parallel chains in which the 

 strata of the tertiary and cretaceous periods 

 mark the date of their elevation. The highest 

 summit is the snow-covered Mount Miltzin, 

 3,461 metres in height. He remained several 

 days at Sidi Hescharn to purchase camels and 

 fit out the caravan, and then crossed the Anti- 

 Atlas. This range, which does not rise above 

 1,500 metres, is of palaeozoic formation. On 

 the farther side of the mountains the village 

 Tisgi was found beautifully situated among 

 springs and date-palms. On a neighboring 



hill are ruins which are said to be of Roman 

 origin. The extent of the traffic between 

 these border-lands of Morocco and Timbuctoo, 

 and the importance of the mart Tenduf, have 

 been reported by the Rabbi Mordochai and 

 others. Thither Lenz's modest caravan was 

 next conducted. They found a prettily situated, 

 young, and growing commercial town. More 

 camels were procured, a guide engaged, and 

 the final preparations for the long march 

 through the Sahara were concluded. Four 

 days out from Tenduf they entered the sandy 

 desert, which was not, however, devoid of all 

 life, for here and there were patches of vege- 

 tation, affording forage for the camels, and oc- 

 casionally gazelles and antelopes were seen. 

 On the 18th of May there was even a fall of 

 rain. The course of the march was due south- 

 east from Tenduf to Taodenni, and then about 

 southerly to Timbuctoo. Not far from Tenduf 

 they entered a wide stretch of hard and rocky 

 ground, almost .destitute of water. In thirty- 

 one days they passed only four wells. This 

 description of surface, hard, arid, and free 

 from shifting sands, is called hammada. They 

 next passed through a zone of aregs, or sand- 

 dunes, before reaching the salt-beds of Tao- 

 denni. The hills of sand, heaped up by the 

 wind, were exceedingly difficult to cross. The 

 temperature was agreeable for night-marches, 

 the mean not exceeding 34 or 36 C., and 

 cool northwest winds prevailing. The latter 

 fact militates against the theory of the forma- 

 tion of the desert by the constant passage of 

 currents of dry air from the northeast. The 

 other theory, that the Sahara formed the bot- 

 tom of a sea in recent geological time, is con- 

 sidered unfounded by Lenz, who ascribes the 

 accumulation of sand mainly to the erosion of 

 the mountains, which is still going on over the 

 vast surface of the hammada plains. The fact 

 that the fossils contained in the rocks here are 

 of fresh- water animals proves that the sand 

 was not formed by marine action, and that 

 this portion of the Sahara is not, as has been 

 supposed, the elevated bed of a tertiary sea. 

 The phenomenon of singing sand was heard. 

 This is supposed by Lenz to be the effect of 

 friction upon the heated quartz-grains. The 

 aspect of the Sahara is varied, plains of sand 

 succeeding rocky ground, with occasional oases 

 covered with alfa, containing stagnant or shal- 

 low pools of water. The barometric observa- 

 tions of Dr. Lenz put an end to the adventur- 

 ous scheme for the inundation of the western 

 Sahara. No part of the desert was found to 

 lie below the ocean-level. The average eleva- 

 tion was from 250 to 300 metres. The region 

 about Taodenni forms a depression in which in 

 one spot, at Wady Telli, an elevation of only 148 

 metres was measured. They did not venture 

 to visit Taodenni and its salt-mines, making a 

 detour to the eastward which brought them to 

 the interesting Wady Telli. The walls of this 

 ancient town were made of rock-salt and clay. 

 Implements of the stone age made from diorite 



