April 1 6, 1885] 



NATURE 



55i 



Of Timbuktu Dr. Lenz gives on the whole a satisfactory 

 account. During his residence in the place from July 1 

 to July 18, 1SS0, he was hospitably entertained by the 

 Kahia, a sort of " Btirgomeister," or civil magistrate, who 

 s mayor, aldermen, and town council all rolled into one, 

 but who possesses no political authority whatsoever. 

 Since its capture by the Fulahs in 1S26, when the fortifi- 

 cations were razed, Timbuktu has been a purely com- 

 mercial town, a general emporium for Western Sudan, 

 open to all comers — that is, to all the " Faithful," but un- 

 fortunately a constant [bone of contention between the 

 rival Tuarik (Berber) and Fulah tribes of the surrounding 

 lands. At the time of Dr. Lenz's visit, the Tuariks, 

 under their " Sultan " Eg-Fandagumu, were in the 

 ascendant, but, beyond levying dues on the imports and 

 exports, neither they nor the Fulahs ever interfere in the 

 local administration, which is left in the hands of the 

 Kahia. This office itself is hereditary in the Moorish 

 family of Er-Rami, originally from the South of Spain, 

 hence known as " Andalusi," and settled in Timbuktu 

 since the sixteenth century. The present Kahia affects 

 the title of "amir," and is said to be aiming at the sovereign 

 power by making himself independent of the Tuarik and 

 Fulah factions. In this he appears to be encouraged by 

 the French, who have lately reached the Niger at Segu, 

 and who have quite recently induced him to send an 

 "envoy" to Paris. 



During the journey from Timbuktu to the Senegal Dr. 

 Lenz saw a good deal of the Fulahs, who are now every- 

 where interspersed among the Negro populations from 

 Wadai and Darfur to Senegambia, and to whom appa- 

 rently belongs the future of Central and Western Sudan 

 between the Niger and Wadai. Unfortunately, in discussing 

 the origin of this mysterious race, he revives the now ex- 

 ploded theory of a " Nuba-Fulah" family, first suggested 

 by Friedrich Midler, the learned but somewhat venture- 

 some Viennese ethnologist. At least Dr. Lenz goes so 

 far as to say that, "touching the ethnographic position of 

 this people Friedrich Muller has probably hit the mark 

 in grouping together the Nubas and the Fulahs, whom 

 he collectively calls Nubas, and divides into a western 

 and eastern section" (p. 261). This might not be in 

 itself so surprising but for the fact that he further on 

 refers to the writings of G. A. Krause on the subject. 

 Now Krause distinctly separates the Fulahs from the 

 Nubas, or rather ignores the connection altogether, and 

 allies them to the Hamites, calling them " Ur- oder Proto- 

 hamiten." It may be added that with the materials 

 now available (Lepsius, Nachtigal, Faidherbe, Newman, 

 Krause, Reinisch, &c), it seems possible to determine 

 the mutual relations of all these peoples with some show 

 of probability. But in any case the Fulahs are certainly 

 not Nubas, nor are the Nubas Hamites. 1 Whether 

 Krause is right in affiliating the Fulahs to the Hamitic 

 group, "mag dahingestellt werden," at least pending 

 further information. The type is distinctly non-Negro, 

 differing from it in almost every racial characteristic — 

 cranial formation, complexion, texture of the hair, figure, 

 proportion of members, mental qualities. Dr. Lenz, who 

 had numerous opportunities of studying full-blood speci- 

 mens, was amazed at their striking resemblance to Euro- 



1 On this point the reviewer must refer the reader to his " Egyptian 

 Ethnology." Stanford, 1SS5. 



peans, and describes them as of light complexion, with 

 slightly arched nose, straight forehead, fiery glance, long 

 black hair, shapely limbs, tall slim figures, great in- 

 telligence. At the same time, since their diffusion among 

 the Sudanese populations the Fulahs have become much 

 modified by crossings with the Negroes and Arabs. " No 

 territory or state is now found exclusively inhabited by 

 pure Fulahs, who are everywhere intermingled with 

 Negro and Arab communities " (p. 259). 



The work is illustrated with some good woodcuts and 

 plates, mostly from photographs and sketches by the 

 author, who has also added a general map of the region 

 traversed, and as many as eight carefully prepared 

 itineraries of its'several sections. A. H. Keane 



OUR BOOK SHELF 

 Physical Arithmetic. By A. Macfarlane, D.Sc. (Lon- 

 don: Macmillan and Co., 18S5.) 

 THIS is a very thorough work, and one admirably adapted 

 for the use of physical students : indeed, we think so well 

 of it that we would recommend it for use in all schools 

 and establishments where the subjects of which it treats 

 are taught. There is a great amount of matter, tersely 

 put and aptly illustrated by copious worked-out examples, 

 and, in addition, there is good store of exercises to try the 

 pupil's strength. Answers are appended, and a useful 

 index crowns all. 



What is its subject-matter ? It treats, we should say, de 

 omni scibili, and perhaps de quibusdam aliis. But to 

 descend to particulars : there are nine chapters, and in 

 these are discussed matters financial, geometrical, kine- 

 matical, dynamical, thermal, electrical, acoustical, optical, 

 and chemical. Have we not rightly described its subject- 

 matter above ? Dr. Macfarlane has done much good work 

 in other directions, ard in this particular direction he 

 gives us, not the result of two or three months' turning- 

 over of text-books, but what he has noted down since his 

 student days ; hence he speaks of what he does know. 

 A diligent student, an original researcher, he has learned 

 and assimilated methods arrived at by such masters in 

 physics as Thomson, Maxwell, Tait, Everett, and Chrystal, 

 and put them together here in orderly method. This 

 method the author calls the equivalence method. "Each 

 quantity is analysed into unit, numerical value, and, when 

 necessary, descriptive phrase. The rate, or law, or con- 

 dition, according to which one quantity depends on one 

 or more quantities, is expressed by an equivalence. These 

 equivalences are of two kinds — absolute and relative ; the 

 former expressing the equivalence of dependence, the latter 

 the equivalence of substitution or replacement." 



We cannot give a brick, but we feel sure that the edifice 

 to which we liken the book will be found to be con- 

 structed on thoroughly sound principles, and that no 

 student who buys it on our recommendation will regret 

 having done so. 



It would take a very long time to test the furniture (i.e. 

 the examples) ; upon its suitability, we cannot now 

 pronounce an opinion ; moreover, each student will have 

 his own particular room to explore : after a visit to all 

 the rooms, each appears to be quite comme ilfaut. 



Coordonnees paralleles el axiales. Melhode ,le Transforms- 



. imetrique et P 'roce'de nouveau de Calculgraphiqtte, 



deduits de la Consideration des Coordonnees paralleles 



Par Maurice D'Ocagne. (Paris : Gauthiers-Villars, 



18S5.) 



Two fixed points, A, B, called the origin of co-ordinates, 



are taken, and through them are drawn two parallel 



straight lines, Au, Bv ; these are called axes of co-ordinates 



(or co-ordinate axes). Lengths, AM, BN, measured on 



