Reviews — Dr. J. W. Gregory's Great Rift Valley. 327 



were straight, and that its angles retained some of their original 

 sharpness, for the direct action of faults and earth-movements still 

 dominated the scenery. An hour after entering this valley, we 

 reached the edge of the Great Rift Valley, which, like the former, 

 must be directly due to earth-movements. Once the plateaux of 

 Mau and Kikuyu were continuous across the site of the Rift Valley ; 

 a double series of north and south [faults] cut through the plateaux 

 and allowed the block of material between them to subside. This 

 left a great open Rift Valley (or, to use Prof. Suess's term, a 

 'Graben'). In this method of valley formation strips of country 

 have fallen owing to a series of parallel cracks or 'faults,' and thus 

 a valley has been formed with precipitous, and sometimes step-like 

 sides. Such valleys have long been known in America, and the 

 extraordinary steepness of their bounding walls may be seen in 

 photographs of the Yosemite Canon in California" (p. 220). We 

 have dwelt rather more fully upon this part of Dr. Gregory's book, 

 because he tells us that the desire to obtain more precise information 

 as to the structure and origin of this Great Rift Valley was the main 

 reason for his undertaking the journey described in this volume. 



We commend Dr. Gregory's book most highly for its many-sided 

 and suggestive views on a great variety of subjects, which are most 

 ably discussed, and with a freedom of opinion and an absence of 

 prejudice truly refreshing. We were much struck by the author's 

 remarks that much of the political trouble in East Africa has arisen 

 in consequence of our interference with that most ancient and 

 well-recognized institution of slavery, which has doubtless been 

 maintained by the Arabs for more than 3,000 years in the country, 

 and could not be interfered with save by provoking the deadly 

 hatred of this most powerful and intelligent race. " We have tried 

 to destroy that which was an integral part of the social system of 

 the ruling race, without realizing how vast a cavity would be pro- 

 duced, and how fatal it would seem to them. 



" At Melindi, at Mambrui, and Magarini, in fact all along the 

 coast, extensive plantations are being abandoned owing to the 

 impossibility of obtaining sufficient labour. The Arabs see their 

 property being ruined, and are naturally hostile to British rule." 



" The system of slavery in East Africa is really that of 



serfdom, and has been as necessary in the development of the 

 country as feudalism was in Europe. Under the laws now in force 

 the slaves will gradually die out and be replaced by freemen, and 

 the change had far better come slowly than by a sudden revolution " 

 (p. 380). 



We must now bid the author adieu. We advise those who would 

 enjoy a delightful and attractive volume to procure Dr. Gregory's 

 charming book and read it for themselves. 



By the kindness of Mr. John Murray we are permitted to 

 reproduce on our Plate XI two types of African lake-shores, 

 namely, that of Victoria Nyanza and the western wall of Lake 

 Tanganyika, both taken from Dr. Gregory's work, p. 3. 



