May 29, 1919] 



NATURE 



«i,i 



Mr. E. Tordav contributes to the April issue of 

 Man an interesting account of the Northern Babunda 

 tribe, an offshoot of the Kimbundu of Angola. They 

 are a fine, tall, heavy-boned, short-legged, very dark 

 skinned race, with pleasant features. With the ex- 

 ception of infants they are all clothed, not in Man- 

 chester goods, but in cloth home-made from the fibre 

 of the raphia palm. All negroes are keen traders, 

 and trade is the principal occupation of the men ; but 

 a great market is scarcely ever held which does not 

 end in a fight between two hostile factions. The 

 crops of the field belong to the woman who tilled it, 

 and it is her duty to feed her husband and her children. 

 Large numbers of slaves are kept, who may be freely 

 sold, but the owners cannot put them to death. No 

 persons who can trace a common ancestor are allowed 

 to marry, and prenuptial infidelity is the normal rule. 

 They are fond of music, and sing better than any 

 other tribe on the Congo. A large collection of their 

 musical instruments has been made for the British 

 Museum. 



The attention of coleopterists may be directed to 

 Dr. F. H. Gravely's "Contribution towards the 

 Revision of the Passalidae of the World " (Memoirs 

 Indian Museum, vol. vii., No. i, pp. 146+16 figs.+ 

 I plate, December, 1918), in which, in addition to the 

 systematic part, the external morphology, classifica- 

 tion, and geographical distribution of these beetles are 

 discussed. 



The Commonwealth Bureau of Meteorology has pub- 

 lished in one sheet a layer-coloured orographJcal 

 map of Australia on an approximate scale of a,\ mil- 

 lions. The map has been compiled by Dr. Griffith 

 Taylor, who has collected all the available data for the 

 task. In the little known and the unexplored parts 

 of the country the contours are only roughly approxi- 

 mate; in fact, Dr. Taylor describes all die contours 

 as form lines. A note appended to the map gives 

 the authority for the data used in each State. Some 

 improvement might well be made in the lettering and 

 printing:, but the map, on the whole, is a useful pro- 

 duction and a great improvement, from the oro- 

 graphical point of view, on pre-existing maps. It 

 may be taken for the time being as the authorita- 

 tive version of the relief of Australia. 



An interestmg experiment on the registration of 

 distant earthquakes is described by Messrs. T. A. 

 Jaggar and A. Romberg in the Bulletin of the Seismo- 

 logical Society of America (vol. viii., 1918, pp. 88-89). 

 An Omori horizontal pendulum was used, but the 

 smoked paper and stylus were replaced by an optical 

 system. The arm of the pendulum was continued by 

 a magnetised steel needle. A second needle of the 

 same size was fixed to the back of a light circular 

 mirror, at right angles to the mirror, and with its 

 north pole close to the south pole of the arm magnet. 

 The mirror was cemented to a vertical taut silk fibre 

 held on a post standing on a concrete table, and both 

 pendulum and mirror were damped by projections 

 iinmersed in oil. During a horizontal "displacement 

 of the ground the supports of the pendulum and 

 •iiirror were moved, while the frictionless magnets 



rated the minor round a vertical axis. The seismo- 

 .lam reproduced (July 2, 1918), made on a Kodak film 

 travelling at 32 mm. per minute, shows the first and 

 second preliminary phases with extraordinarv clear- 

 ness. 



Ik connection with recent efforts to promote the 

 . uJtivation of sugar in Bihar, Rai Bahadur Joges 

 Chandra Ray publishes an interesting article in the 

 Journal of the Bihar and Orissa Research Society 

 (vol. iv., part iv.) on the sugar industrv in ancient 

 India. In the Vedas there is no mention of any 



NO. 2587, VOL. 103] 



saccharine substance other than honey. Cane was cul- 

 tivated, but we do not know whether it was used 

 for chewing or pressed, or whether its juice was 

 dried for future use. The original seat of the cultiva- 

 tion of the Paunda, or thick cane, seems to have 

 been northern Bengal. We do not know how the 

 ancients clarified the cane-juice or refined their sugar. 

 Probably the method was much the same as that 

 which obtains now in Bengal and elsewhere, and 

 clarification was secured by skimming off the scum 

 which rises to the surface. It is remarkable that 

 no account of palm-sugar is found in ancient Sanskrit 

 works, and the industry in Bengal seems to be of 

 comparatively recent date. There is a prejudice 

 against its use. as the tree yields an intoxicating 

 beverage. 



Bulletin No. 3 of the Scientific and Industrial 

 Research Department consists of a study of the per- 

 formance of night glasses by Mr. L. C. Martin, of 

 the Imperial College of Science, London. The 

 work arose out of the exacting demands the 

 war made on the optician for a telescope suit- 

 able for observing in a feeble light, and the 

 object was to determine the best proportions and 

 conditions of use of an instrument with a given size 

 of objective. The author's conclusions may be sum- 

 marised as follows : — The binocular form is most con- 

 venient. For hand binoculars for general purposes a 

 magnification of 6 should not be exceeded. The exit 

 pupil should be 07 or 08 cm. in diameter, and a large 

 field of view is desirable, as it increases the ease of 

 observation. For stand instruments a magnification 

 of 10 is most suitable for general purposes. Where 

 higher magnification is necessary it is of the utmost 

 importance to protect the observer's eve and the field 

 of view from all stray light. To diminish the number 

 of glass air surfaces, a cemented prism erecting svstem 

 should be used. 



A PAPER contributed by S. L. Archbutt and D. 

 Hanson at the recent meeting of the Institute of 

 Metals describes in detail the methods found most 

 suitable for the preparation of specimens of aluminium 

 alloys for microscopic examination. Particular care 

 must be given to the grinding and polishing opera- 

 tions, since the successful development of the micro- 

 structure depends to a very large extent on the condi- 

 tion of the prepared surface. Hand-grinding on 

 graded emery papers which have been previously 

 soaked in paraffin is found to give excellent results, 

 while for the polishing operation a motor-driven disc 

 covered with smooth-surfaced woollen cloth is em- 

 ployed. Magnesia is used as the polishing powder, but 

 for soft alloys the final stages are carried out on a wet 

 pad practically free from magnesia. With regard to 

 the etching both of aluminium and its alloys, the 

 authors recommend a 10 per cent, solution either of 

 caustic soda or of hydrofluoric acid in water. Methods 

 for the identification of the various impurities oc- 

 curring in aluminium and of the different micro- 

 graphic constituents found in the commoner aluminium 

 alloys are also described. These have been investi- 

 gated in great detail with the object of finding re- 

 agents which will distinguish between these different 

 constituents when thev occur in the same alloy. 

 .Alloys of aluminium with silicon, iron, copper, zinc, 

 nickel, magnesium, and manganese are considered in 

 this connection. 



We are very glad to see that M. L.-P. Clerc, who 

 is so well known in this country, and took up 

 military duties at the very beginning of the war, has 

 resumed his activities in connection with the French 

 Photographic Society. In a recent issue of the 

 society's Bulletin M. Clerc publishes a paper (repro- 

 duced in the British Journal of Photography for 



