340 



NA TURE 



[August 12, 1897 



attractive to those who are not gifted by nature with the 

 ability to follow abstract reasoning, but who are often 

 very capable of understanding things concrete. They 

 will find also much material for home work. 



If the methods here used were more generally intro- 

 duced into the teaching of mathematics at school, the 

 number of boys declared incapable of learning mathe- 

 matics would, we feel sure, decrease to an astonishing 

 degree. And indeed the same methods might probably 

 be used in other subjects, and then the science side of 

 secondary schools might lift its head and cease to be 

 the refuge of those who can " neither learn classics nor 

 mathematics." O. Henrici. 



TRAVELS IN THE INTERIOR OF SOUTH 

 AFRICA. 

 The New Africa : a Journey up the Chobe and down the 

 Okovanga Rivers : a Record of Exploration and 

 Sport. By Aurel Schulz, M.D., and August Hammar, 

 C.E. Pp. xii + 406. (London : Heinemann, 1897.) 



THE principal title of this work can hardly be said to 

 be quite applicable to its contents, seeing that the 

 journey it describes was made no less than twelve years 

 ago, before the "scramble for Africa" had reached its 

 full height. In spite, however, of the length of time 

 which has elapsed since the events recorded took place, 

 there is much in Dr. Schulz's pages which well repays 

 perusal. To the class of readers which looks chiefly for 

 an agreeable narrative of sport and adventure, it offers 

 abundant attractions, while those who prefer more solid 

 matter will find scattered through it a considerable 

 amount of information on the country passed through. 



Dr. Schulz, who shortly before his journey had 

 qualified in medicine in Berlin, set out from Natal in 

 March 1884, accompanied by Mr. Hammar, on an 

 exploring expedition into the remote interior of South 

 Africa. Proceeding through the Transvaal and Khama's 

 country to the Zambezi, the travellers next ascended the 

 Chobe, its western tributary, to nearly 17° S. lat., and 

 crossed over to the Kubango or Okovanga (this, and not 

 Okavango, is Dr. Schulz's spelling), the principal feeder 

 of Lake Ngami. This river was followed down to the 

 lake, and Khama's country was reached on the return 

 journey by way of the Zuga. A great part of this route 

 led through country rendered classic by the early labours 

 of Livingstone, and since traversed by a host of sports- 

 men and explorers ; but a certain amount of new ground 

 was broken in the region of the Chobe and Okovanga, 

 and as a careful survey was made by Mr. Hammar, some 

 real addition to our knowledge resulted from the journey. 



The whole region stretching northwards from Lake 

 Ngami is so level that the rivers form a complex net- 

 work, the details of which are even now far from com- 

 pletely understood. The confusion is heightened by the 

 fact that several of the streams flow in one direction, or 

 the reverse, according to the time of year. It has long 

 been supposed that the Okovanga sends some of its 

 waters to the Chobe, some finding the connecting channel 

 in the Mababe just west of 24° E. Dr. Schulz claims to 

 have ascertained the existence of another branch of the 

 Okovanga leading to the Chobe. The point of bifurcation 

 w^as not seen, but an important channel was found to 

 NO. 1450, VOL. 56] 



enter the Chobe from the west, and native accounts con- 

 firmed Dr. Schulz's suspicion that it came from the 

 Okovanga. The route followed by the expedition led 

 through a barren region of sand-belts, in which the 

 travellers suffered from want of water. The sight of the 

 Okovanga — a fine stream 400 yards broad, of the capa- 

 bilities of which as a water-way the author expresses a 

 high opinion — was therefore most welcome. It was 

 struck at the town of Debabe or Indala (identical, it 

 appears, with " Andara, or Debabe's town," reached by 

 Green in 1856), and although its course hence to Lake 

 Ngami had previously been explored by that traveller, 

 Andersson and others. Dr. Schulz was able to define, 

 more precisely than they had done, at least the western 

 bank of the series of swamps which mark the course of 

 the river. During this part of the journey the travellers 

 were virtually prisoners, being taken for spies of the 

 Matabele, and conducted under guard to Moremi, chief 

 of the country near the lake, whose people retained no 

 pleasant memory of a Matabele raid to which they had 

 nearly succumbed a few years before. The lives of 

 Dr. Schulz and his party were in some danger for a time, 

 but were saved by the testimony of a child who had been 

 vaccinated by the doctor at Shoshong on the way up. 



The book abounds with stories of encounters with the 

 wild animals of South Africa, and gives interesting 

 details illustrating their habits. They were especially 

 plentiful near the Chobe, where their numbers had not 

 yet begun to be thinned by the persecution of sports- 

 men. One valley is described as having seemed a 

 teeming mass of life, troops of every variety of game 

 appearing to view at the same instant. Dr. Schulz has 

 a good deal to say anent the Mosaros, a desert tribe with 

 which he came in contact, and which he considers a 

 fugitive branch of the Hottentots, distinct from the Bush- 

 men proper, though often called by that name. The 

 book is not provided with an index, but contains a map 

 showing the features of the country along the line of 

 route, with some information on the surface geology. 

 Some of the illustrations give a good idea of the types of 

 country and vegetation common in South Africa. 



OUR BOOK SHELF. 

 Contributions to the Analysis of the Sensations. By Dr. 

 E. Mach, Professor of the History and Theory of 

 Inductive Science in the University of Vienna. Trans- 

 lated by C. M. Williams. Pp. xi -t- 208. (Chicago : 

 Open Court Publishing Co., 1897.) 

 Prof. Mach has expressed his approval of this trans- 

 lation of his " Beitrage zur Analyse der Empfindungen." 

 For the most part it has been excellently rendered into 

 English ; but occasionally there are sentences that read 

 queerly — e.g. " Relatively greater permanency exhibit, 

 first, certain complexes of colours," &c. (p. 2) ; "Merely 

 its application is not complete " (p. 32) ; " Different is my 

 opinion with regard to Strieker's views on language" 

 (p. 131) ; " If the process is over with . . ." (p. 157). 



Every one who is interested in psychophysics will wel- 

 come an examination of the sensations by a leading 

 physicist, especially when his analysis is so suggestive 

 and his style so delightful as Prof Mach's. The style is 

 greatly superior to the mode of construction of the book. 

 It would be an exaggeration to say that it, is mainly 

 built up of footnotes ;rbut there are three prefaces, two 



