128 



NATURE 



[October i8, 19 17 



of the negro languages between the Shari River 

 on the east and the forests of West Africa, over- 

 laid as these innumerable types of speech may 

 be by other unrelated tongues, implanted at a 

 later date in Equatorial Africa. We now know 

 that the range of actual Semi-Bantu languages 

 extends from the Lower and the Upper Gambia 

 eastwards to the watershed of Lake Chad. Mr. 

 Du Plessis lays stress on the ethnic importance 

 of the A-zande, or Nyamnyam. Undoubtedly they 

 will play a part in the future development of the 

 western' Bahr-al-Ghazal and the Mubangi-Wele 

 basin as important as that of the Fula in Nigeria 

 or the Mandingos of Senegambia. 



Much information is given concerning the 

 artistic aptitudes of various negro peoples, espe- 



has long been one of the primary aims of 

 astronomy to execute this enumeration. Consider- 

 able difficulties of a practical nature have to be 

 faced in the course of the work, however, and only 

 now do they appear to have been so far overcome 

 as to enable a consensus of opinion to be formed 

 amongst astronomers regarding the main features 

 of the results. Whether visual or photographic 

 methods are used, it is anything but easy to deter- 

 mine star magnitudes according to an absolute 

 scale of light-ratio, and to maintain a constant 

 zero point for the scale in widely separated regions 

 of the sky. 



The photometric work done at the Harvard and 

 Mount Wilson observatories has greatly facilitated 

 this task, and at these institutions, moreover, 



Fig. 2. — A specimen of native art (British Nyasaland). From "Thrice through the Dark Continent.' 



cially of the Nyamnyam, the Basonge (of central 

 Congoland), and the A-nyanja of Nyasaland. A 

 good deal of this desire to draw and paint and 

 decorate is subsequent rather than prior to the 

 establishment of European influence. Personally 

 I believe that the negro may rise very high in 

 the pictile arts, and that he has an inherent good 

 taste and originality in design. 



H. H. JOHNSTOX. 



THE NUMBER AND DISTRIBUTION OF 

 THE STARS. 



AN enumeration of the stars, classified accord- 

 ing to their brightness and their position in 

 the sky, must form a part of any general investi- 

 gation into the nature of th? stellar universe. It 

 NO. 2=503, VOL. IO0I 



extensive schemes for the photographic survey of 

 sample areas of the sky have recently been carried 

 out. The Harvard plates have been measured, 

 and a preliminary discussion of them made, at the 

 Groningen Astronomical Laboratory ; an account 

 of this work,i and a brief note ^ upon that done at 

 Mount W^ilson, have lately appeared. In both cases 

 the investigation has been extended to very faint 

 stars (of magnitude i5'5 and i7'5 respectively);- 

 these are so numerous that counts of small sample 

 areas, and the formation of statistical averages, 

 afford the only practical means of attack upon the 

 problem. The areas dealt with were among those 



1 Publications ef the Astronomical Laboratory at Groningen. No. 27' 

 "On the Numb'-r of Stars of Each Photoersphic Magnitude in Diflferen' 

 Galactic Latitudes." By Dr. P. J. van Rhi>n. (1917.) 



2 F. H. Scares, Proc. Nat. Acad. Sci., Washington, v 1. iii., p. 217. 

 (1917.) 



