July 26, 1906] 



NA TURE 



309 



four yoars (1869-1903), making the ninth successive year 

 of low floods. Tine mean rainfall, and the oscillation of 

 ihi: rain-belt with the apparent motion of the sun, are very 

 clc-arly shown by coloured maps, drawn for each month. 



The report of the l-"almouth Observatory commillee of 

 the Royal Cornwall Polytechnic Society for the year 1905 

 (one of the principal observatories subsidised by the 

 Meteorological Office) shows that a record reading of the 

 barometer for that part of the British Islands occurred on 

 January 28, viz. 31097 inches (corrected and reduced 10 

 sea-level). The next highest reading at Falmouth during 

 the last thirty years was 30-981 inches, on January iS, 

 1882. Another interesting point is the mean temperature 

 of the sea-surface, taken one mile outside the harbour, 

 viz. 53°'3, being 2°-3 above the mean temperature of the 

 air. The mean monthly sea-temperature w^as only below 

 that of the air in June, July, and August. Much attention 

 is given to magnetic observations, and the instruments are 

 not affected by electric tramways. During a display of 

 aurora borealis on the night of November 15, an easterly 

 movement in the declination took place 

 at Sh. 53m. p.m. which in twelve minutes 

 r<duced it about 33', while in the subsequenl 

 twenty minutes the declination increased 

 about 41', which was 8' west of its position 

 before the movement occurred. 



The Jahrbuch of the Norwegian Meteor- 

 ological Institute for 1905 contains hourly 

 observations for Christiania, with tri-daily 

 readings and summaries for other stations. 

 The results are given according to the 

 international scheme, as before, the onl\ 

 change being that mid-European time has 

 been introduced (one hour earlier than 

 Greenwich), so that the observations at 

 telegraphic reporting stations, which were 

 previously taken by Christiania time, are 

 now made seventeen minutes earlier than in 

 previous years, while at the ordinary stations 

 ilio time of taking observations has not been V; 



altered. Accompanying the Jahrbuch is 

 part xiv. of the valuable series of climato- 

 logical tables for Norway, containing the 

 average monthly amount of cloud for the 

 various directions of wind (" cloud wind- 

 roses ") ; at most of the stations the averages 

 arc for a period of twenty years (1876-95). 



The trigonometrical branch office at Dehra 

 Dun has published a valuable series of daily I 



rainfall observations for each of the thirty- 

 six years 1868-1903. The mean annual 

 fall is 84.72 inches, of which 65 per cent, falls in 

 July and August. The maximum yearly amount was 

 12247 inches, in 1894, and the minimum 41.69 inches, in 

 1877. The greatest fall in one day was 12-47 inches, on 

 .'\ugust 10, 1896. From a summary of the highest and 

 lowest temperatures in the shade, for the same years, we 

 observe that the mean of the annual extremes was i04°-3, 

 the absolute maximum being io8°-4, on May 19, 1S92 

 (io8°-3 on June 5, 1890), and the minimum 3i°-S, on 

 January 13, 1874, the next lowest being 33°-9, on I'^ebruarv 

 5. 'S76'- 



COLOURING OF GUEREZA MONKEYS. 

 T X vol. ii. of the Proceedings of the Zoological Society 



of the current year, Mr. Lydekker contributes a paper 

 on colour-evolution in the black or black and white tropical 

 African monkeys of the genus Colobus commonly known 

 as guerezas. Starting with a wholly black monkey, like 

 the West African C. satanas, in which, although there is 

 a fringe of long hair round the face, the body is com- 

 paratively short-haired and the tail not tufted, the author 

 shows how a gradation can be traced through species 

 like C. palUatus and C. sharpei of East Central Africa, in 

 which tufts of long white hair (larger in the second than 

 in the first of the two species named) make their appear- 

 anii- on the sides of the face and shoulders, as well as on 

 the terminal third of the tail, to the Abyssinian C. guercsa, 

 in which the white shoulder-tufts extend backwards to 



form a mantle on each side of the body, and unite on 

 the lower part of the back. The culmination of this type 

 is formed by the white-tailed guereza (C. caudatus) of the 

 Kilimanjaro district, in which the pendent white mantle 

 is still longer, and the tail, which is wholly white except 

 for a small length at the root, is clothed with long pendent 

 hair ; the cheek- and ihroat-tufts, however, have been lost, 

 so that the head is short-haired, with the face and throat 

 white. 



The West African while-thighed guereza (C. vellerosus) 

 appears to exhibit a kind of retrograde development in 

 I these respects, the body having lost the mantle of long 

 I white hair and the tail'ils white "flag," while the white 

 of the perineal patch has spread on to the hinder and outer 

 sides of the thighs. In this case we find practical reversion 

 to the Ivpe of the black guereza, with the exception that 

 the band on the forehead, the sides of the face and throat, 

 the thighs, and almost the whole tail have become white, 

 while the long hair has disappeared from the face. In the 

 opinion of the author the colouring and special develop- 



White-lalled Gu 



(C^/Mns ca:„/a!„s). 

 Zoological Society. 



NO. 191 7, VOL. 74] 



ment of the long hair in the white-tailed guereza form a 

 protective modification, but the purport of the colouring of 

 the intermediate forms between this and the black guereza 

 is left undecided. 



ELECTRICITY IN MINES. 



A VERY great development has taken place during the 

 -'*• past two years in electrical machinery and apparatus 

 for working colliery plant. Manufacturers seem at last to 

 have realised that machines and accessories must be adapted 

 and made to suit the conditions existing in collieries, and 

 that the collieries cannot be adapted to suit their standard 

 machines. Consequently, in the colliery exhibition which 

 has just taken place, the result of experience in colliery 

 work was clearly put before us in entirely new designs of 

 motors and switchgear specially adapted for this work. 



The details of colliery requirements have been most 

 carefully studied and gone into, and the designs prove the 

 tremendous development that has taken place. Whereas 

 a few years ago contractors simply attached their standard 

 machine to a haulage-gear or coal-cutter, and supplied the 

 ordinary switch-gear as for everyday use, to-day we find 

 that it is the general rule for motors to be designed and 

 built for the particular work for which they are intended, 

 and to be made part and parcel of the machine they have 

 to drive. The same applies to the switch-gear, and a large 

 supply of dift'erent forms of specially enclosed switches fcr 



