228 



SCIENCE. 



[N. S. Vol. II. No. 34. 



of culture, of cranial forms, of geographic 

 position, of historic references, he had been 

 led to the conviction that they belonged to 

 the Berber or Libyan groups, that vast 

 ethnic stock which occupied the whole of 

 north Air-ica, west of the Nile Valley, above 

 the Soudan. His arguments seemed to my- 

 self and others quite suflBcient, at least in 

 the present stage of the investigation. 



What is especially noteworthy is the fact 

 that civilization was highest on their ar- 

 rival. Later it degenerated, and finally be- 

 came absorbed in the Egyptian. There- 

 fore, if Professor Petrie is right in his iden- 

 tification, we must credit to the ISTumidian- 

 Libyan tribes of the fourth millenium 

 B. C. a culture of native growth higher in 

 many respects (though inferior in others) 

 to that of the Egyptians who were their 

 contemporaries . 



Of the manj' and brilliant discoveries we 

 owe to the indefatigable zeal of Professor 

 Petrie, this last, of which I give this cursory 

 account, is perhaps the most important for 

 the history and ethnography of the Nile 

 Valley and northern Africa. 



D. G. Beinton. 

 London, Aug. 3. 



CURRENT NOTES ON PHYSIOORAPHY (XIV.). 

 FOUEEAU'S EXPEDITION INTO THE SAHARA. 



For the third time, Foureau has been re- 

 pulsed by the Touaregs in his attempt to 

 cross the desert and reach the inland dis- 

 trict of Air. The nomads resent the intru- 

 sion of European explorers, and do not 

 wish to hear of commerce or trans-Saharan 

 railways. Although not an expert in geo- 

 graphical description, Foureau's account of 

 his unfortunate expedition gives many in- 

 teresting sketches of the hammada, or rugged 

 sandstone uplands, too stony for camels to 

 cross; the erg, or sandy areas of the lower 

 lands, with chains of dunes trending N. E. 

 -S. W., as if controlled by the trade winds; 

 the numerous wadies, or stream courses. 



universally adopted as routes of travel, al- 

 though caravans are here sometimes over- 

 whelmed by floods from which there is no 

 escape where the walls are steep. Gently 

 sloping plateaus (hammada), dissected by 

 long consequent valleys to the north and 

 broken by short and steep obsequent streams 

 on their south-facing escarpments, are 

 characteristic features of the regions south 

 of Wargla, in latitude 27°. Much of the 

 surface near the wadies is minutely dis- 

 sected, and would be called ' bad lands ' by 

 our Western explorers. The barrenness of 

 the stony plateaus is complete; but along 

 the wadies there are acacias and scattered 

 herbage on which horses and sheep find a 

 scanty pasture. A little wheat is raised on 

 the flood plains. Swarms of grasshoppers 

 sometimes consume the vegetation. The 

 people are excessively poor, and all are great 

 beggars, clamoring for gifts. In November, 

 1893, minima of -6° C were recorded 

 several times ; sleeping without a tent, the 

 explorer's blanket was covered with frost 

 nearly every morning. Although suffering 

 from cold, Foureau found, on the other hand, 

 plenty of water in pools along the wadies, 

 for in the five winter months of 1893-'94 

 there was rain on twenty-two days. Snow 

 was seen on the plateaus. On several 

 mornings there was dense fog. The Toua- 

 regs thought the cold spell was brought by 

 the explorers. Moufflons were seen on the 

 hammadas, and antelopes were common on 

 the erg districts (Bull. Soc. geogr., Paris, 

 XVL, 1895, 10-74). 



LACCOLITIC MOUNTAIN GROUPS. 



The fourteenth annual report of the 

 United States Geological Survey contains 

 an interesting chapter on the laccolitic 

 mountain groups of Coloi-ado, Utah and 

 Arizona, by Whitman Cross. It serves as 

 an extension of the report on the Henry 

 mountains by Gilbert of some years ago. 

 While the chief value of this chapter is in 



