228 



NATURE 



[April 13, 1911 



improbable that any chanj^e took place in its length 

 between the time that it left India and its return from 

 Sivres, so that the value of bar A, viz. 3047996 mm. at 

 6a° F. in terms of the international metre, is thoroughly 

 trustworthy. Pendulum work was carried on in the western 

 tracts of the Siitpurd hills and the V'indhyan plateau as 

 an investigation of the variation of gravity in the northern 

 portion of peninsular India, and at seven stations, situated 

 at from 750 feet to 2if)o feet above sea-level, excesses of 

 gravity were found. .At twenty-eight stations above 750 

 feet hitherto observed gravity has never been in excess, so 

 that dissimilar conditions in peninsular and extra- 

 peninsular regions seems to be indicated. Subsequent 

 seasons' work is being extended over Rajputana and the 

 S.^tpurA hills to the (iangetic plain, 'lidal records from 

 nine stations, Moulmein being one which was re-estab- 

 lished, and nearly 1100 miles of double levelling, occupied 

 a portion of the staff, while the Magnetic Survey working 

 in Burma completed the preliminary survey with a total 

 of 1255 stations. 



Some specially disturbed areas were surveyed in detail, 

 and this work is being continued. Heavy prolonged rain 

 at Dehra Hun eventually forced its way into the magneto- 

 graph rtx>m, and, rising within an inch of the top of the 

 driving-dock pillar, necessitated the removal of the instru- 

 ments on .August 15, which were replaced a month later. 

 The Topographical and Forest Surveys also completed the 

 survey of a large area of country. In cartographic work, 

 the results of the reorganisation of the drawing, engraving, 

 and printing branches which was carried out since 1906 

 are now to be seen, and the publication of standard map- 

 sheets has kept pace with the survey and drawing, besides 

 there being a considerable increase in outturn. A speci- 

 men sheet of the i : 1,000,000 map, the strategical map of 

 India, is given, containing the region round Bombay; 

 roads, railways, and boundaries are strongly brought out, 

 but the relief is shown by shadinij, which renders main 

 features prominent, and by (omparatively few inscribed 

 altitudes. 



(2) The Bulletins of the United States Geological Survey, 

 which deal with higher surveying, furnish the final results 

 of work done in the field after all corrections have been 

 applied. The numbers stamped on the bench marks in 

 the field represent the elevations to the nearest foot above 

 mean sea-level as determined by unadjusted levels in the 

 field, and those who require a higher accuracy than 

 2 feet must consult these bulletins or apply to the offices 

 of the Survey. The levelling is classified as precise or 

 primary according to the accuracy of method and precision 

 of the instruments employed, and lines are run both for- 

 ward and backward in the former case, but in one direc- 

 tion only in the latter. The allowable limits of error in 

 feet are respectively 0017 v'D and 005 vT), where D is the 

 distance in miles. In the bulletins the position of each 

 bench mark is described and its altitude given to oooi foot 

 for both classes of work. 



The results of triangulation and primary traverse are 

 likewise given in periodical bulletins, which not onlv give 

 the description of each station, its mark and reference 

 mark, and geographical position, but also the azimuth, 

 back azimuth, and the logarithm of the distance from it 

 in metres of all points observed from it. .An interesting 

 map of the United .States is included showing the astro- 

 nomic location and primary control up to January i, iqoq. 

 While much has been accomplished, large areas remain 

 along the 101st meridian, in the .Southern States, and many 

 other parts to be completed. 



THE STANDARDISATION OF COLOURS. 



rjNDER the title of "International Rules for the 

 Sj>ecification of Colours," Mr. Hans-Jacob Moller 

 has reprinted an essay by him from the Journal of the 

 Danish Apothecaries' Association (Archiv for Pharmaci og 

 Chcmi, November 14, 1910) showing the importance of 

 having an international scheme of colours so as to enable 

 reference to be made to a definite tint on a definite scale, 

 and recommending as the most useful and most practical 

 scheme of the kind that drawn up by Klincksieck and 

 Valette, a scheme based upon the original system drawn 

 up by Chevreul. There can be no doubt that such a 



colour .scheme, recognised throughout the scientific worlil. 

 would be of great practical value. For example, to tak> 

 a very obvious instance, a large number of chemical r- 

 actions in connection with organic substances, such 35 dy 

 stuffs, depend upon colour changes, and if it was ]>■ 

 to describe these colour changes in accurate lang.. 

 would be of great practical value to the chemist. 



When we come to the departments of pigm<nts and «.i 

 dye-stuffs, it is obvious that there, too, a definite reco^ 

 nised colour scheme would be of great practical value. It 

 would, however, probably be better, if once a colour 

 scheme was decided upon, that it should be reproduced in 

 some permanent material such as coloured glass, so as t(j 

 give a definite standard for reference at any futut' 

 as a colour scheme which is merely lithographically 

 may alter owing to fading of the colours, and if an u:. ..., , 

 is made to repeat it, it is seldom that pigments can bt 

 twice reproduced with exactly the same tint. 



On the other hand, an attempt to refer to definite lin'^ 

 on the spectrum is difficult in practice, as the use of th' 

 spectrum in this way for the matching of colours is not 

 very easy, and it is not a satisfactory method. Mr. 

 Moller does not refer to Lovibond's work on this subject 

 and his scheme of coloured glasses. The present writer 

 has found the Lovibond tintometer most useful and capable 

 of very accurate matching, though the Lx)vibond standards 

 are purely arbitrary. .An arbitrary scheme seems the only 

 possible one, and therefore, as Lovibond has devoted so 

 much ingenious labour to the making and matching of hi^ 

 coloured glasses, there is a great deal to be said for 

 defining tints by means of his tintometer, such a tinto- 

 meter being kept as a standard of reference. Whatever 

 may be determined, however, as the best practical solu- 

 tion of this question, it is certainly time that something 

 of the nature of an international colour scheme be adopted, 

 so that there should be no difficulty in referring to a 

 definite scale .ind number in describing any colour. 



A. P. Laurie. 



NO. 2163, VOL. 86] 



DIET AND DEVELOPMENT.' 

 "pHE main impression left by a perusal of this e.\! 

 report upon the diets of labour convicts in 

 jails, referred to below, is that the Indian Government nas 

 been well served in this matter, and has now in its 

 possession advice derived so judiciously from soundly 

 organised and ably conducted investigations as to justify 

 what, on weaker evidence, might have seemed a par- 

 simonious procedure, namely, some limitation of the too 

 ample dietaries of these prisoners. The author may be 

 said to have proved that their vegetarian diet, such as is 

 the common food of the native population, has been pro- 

 vided in quantity so large as to escape digestion. No one 

 will find reason to doubt his statement that this undigested 

 material gives occasion to various forms of distressing 

 trouble whilst in disordered transit through the alimentary 

 canal of its consumers ; not that this point is new, but 

 that the condition has been very definitely shown as exist- 

 ing in this special and important case. 



It would seem that, prior to this investigation, the diets 

 had been arranged so as apparently to display the same 

 " protein value " as a European diet. In the effort of 

 imitating the heavy labour diet of English prisons with 

 combinations of the native food-stuffs, meals of extra- 

 ordinary bulk have been provided. Whereas, when added 

 in small quantity to the varied constituents of a European 

 meal, similar food-stuffs may yield so much as So per cent, 

 of their contained protein for absorption into the tissues 

 of the body, the author has shown that often no more 

 than 50 per cent, is absorbed from them when found as 

 the main constituents of a bulky meal, and this notwith- 

 standing the fact that bulky meals are characteristic of the 

 district, if to a somewhat smaller degree than within its 

 jails. He has also proved that a certain ascertained 

 diminution in this bulk, accompanied by an apparent 

 diminution in the protein value of the diet, is always the 



1 " Investigations on Bengal Jail Dietaries, with .Some Observations on 

 the Influence of Dietary on the Physical Development and Well-being of 

 the People of Bengal." By Capt. D. McCay, I. M.S. Pp. iv-i-2j6-)-i5 

 charts. (Calcutta : Government Printing Office, 1910.) Price Rs. a.6 on 

 4J. 3rf. 



(Scientific Memoirs by Officers of the Medical and Sanitary Department 

 of the Government of India, New Series, No. 37.) 



