July 7, 192 1] 



NATURE 



605 



Societies and Academies. 



London. 

 Zoological Society, June 7. — Prof. J. P. Hill, vice- 

 president, in the chair. — Major S. S. Flower : Remarks 

 upon Testudo Lcithii and T. ibera. — Dr. P. Chalmers 

 Mitchell : Remarks upon a photograph of the death- 

 mask of a young gorilla. — Dr. F, M. Chapman : The 

 distribution of bird-life in the Urubamba Valley, 

 Peru. — S. Maulik : New Indian Drilid beetles. — Prof. 

 J. P. Hill : Some marsupial embryos, especially the 

 koala (Phascolarctos) and the wombat (Phascolomys). 

 — R. I. Pocock : The external characters of the koala 

 (Phascolarctos) and some related marsupials. — Dr. 

 C. F. Sonntag : The comparative anatomy of the 

 koala (Phascolarctos) and the vulpine phalanger 

 (Trichostirus vtilpecula). — C. T. Regan : The Cichlid 

 fishes of Lake Nyassa. 



Royal Meteorological Society, June 15. — Mr. R. H. 



Hooker, president, in the chair. — G. M. B. Dobson : 

 The causes of errors in forecasting pressure gradients 

 and upper winds. The usual method of checking the 

 accuracy of forecasts by finding their absolute error 

 is misleading, particularly when the weather is very 

 settled. It would be better to find the improvement 

 obtained by "forecasting," e.g. to compare the 

 absolute error of the forecast, made for 

 twenty-four hours ahead, with the actual change 

 of direction in the twenty-four hours. Trial fore- 

 casts of the pressure gradient when checked thus 

 showed but small improvement ; the inaccuracy 

 in estimating the future positions of centres of high 

 and low pressure is a large factor, but a greater error 

 is due to the small irregularities of pressure which are 

 local and transitory, and which, therefore, seem 

 almost impossible to forecast. — R. F. Granger : The 

 physical structure of cloud form in the lower atmo- 

 sphere. Beginning with a constructive criticism of 

 the theory of cumulus formation, the behaviour of 

 eddy-formed stratus sheets, the possibility of outward 

 radiation at night, causing cloud formations, and the 

 formation of sub-strata underneath various typ>es of 

 cloud sheet are discussed. The last part of the paper 

 deals with cyclonic nimbus, and describes the cloud 

 structure of a cyclone while rain is falling : that actual 

 rain-producing cloud is formed by the ascent, en 

 masse, of the eddy-formed damp layer. A cirrus-like 

 cloud forms at low altitude during the passage of 

 one air current over another if the movement set up 

 by friction causes the elevation of a damp layer in 

 the upp>er air current. The interpretation of cloud 

 form in terms of physical structure will probabjy have 

 a place in the weather forecasting of the future. — 

 N. A. Comissopulos and J. Wadsworth : Variability of 

 tem{)erature over Europe and North America 

 (iqoo-9). The variability of temperature is measured in 

 this paper by standard deviations from the mean of 

 ten values of the annual mean temperature from 

 1900 to igoq for a large number of European and 

 North American stations. The small number of years 

 considered is an objection, but consistent results have 

 been obtained. No correlation is found between alti- 

 tude and temperature variability, but a fair connection 

 is indicated between latitude and temperature varia- 

 bility. Charts of isopleths representing variability of 

 temperature show generally an increased variability 

 towards the north, but a decrease towards the coasts. 

 Secondary maxima and minima occur, the positions 

 of which follow the configuration of the land in 

 Europe; maxima occur over N.E. Russia, W. Grer- 

 many, France, and Spain, and minima over the 

 Atlantic and Mediterranean. A chart of S.W. Europe 



NO. 2697, VOL. 107] 



for 1890-99 showed the same general features a» 

 that for 1900-9, but with different absolute values 

 for the various isopleths. 



Royal Statistical Society, June 21. — Sir R. Henry Rew, 

 president, in the chair. — Mrs, W. J. Barton : Women's 

 minimum wages. The main sources of the figures 

 given were the wage rates for unskilled women col- 

 lected in the Labour Gazette and those settled by the 

 Trade Boards. The rates quoted were all minima, 

 and it was difficult to ascertain the proportion of 

 workers earning more than the prescribed rates. The 

 paper dealt with the groups of women workers 

 affected by Trade Board legislation ; e.g. the distri- 

 butive trades, sewing trades, laundries, sugar, con- 

 fectionery, and fruit-preserving trades, paper and 

 printing trades, and the metal trades. Each trade 

 was examined in detail; tables were submitted 

 showing the Trade Board rates payable in dif- 

 ferent districts and the changes therein at different 

 dates, and where possible the various wages paid by 

 voluntary agreement between employers were given 

 for comparison with the legal rates. Trade Boards had 

 raised the*wages of the lowest paid workers, and un- 

 controlled trades had been strongly influenced, while 

 several trades possessing Trade Boards had agreed 

 upon rates considerably above the legal minimum. A 

 minimum standard wage for the unskilled work of 

 women and girls had been created. 



Mineralogical Society, June 21. — Dr. A. E. H. Tuttoti, 

 p>ast president, in the chair. — Dr. H. Hilton : A note on 

 crystal measurement. Labour could be saved by 

 measuring the angles between zones through two faces 

 instead of the angles between zones through one face 

 and the angles between this face and the rest. — A. 

 Brammall : • The trend of reconstitution processes in 

 shales, slates, and phyllites. The author correlates 

 microscopical data with data deduced from chernical 

 analyses. The finely powdered rock is extracted with 

 (a) 20 per cent, of hydrochloric acid, (b) 50 per cent, 

 of hydrochloric acid, and the extracts are analysed and 

 discussed with reference to the molecular proportions 

 of the bases present. The residual slime is treated 

 with dilute hydrofluoric acid, freed from silica gel, and 

 thoroughly washed. Free carbon particles are floated 

 off by the froth produced on vigorously shaking up the 

 slime with water to which a few drops of amyl alcohol, 

 paraffin, and sodium silicate have been added. 

 Samples of coarse-grade and fine-grade sericite are 

 separated by elutriation and analysed. Heavv or in- 

 soluble residues are obtained and examined. Data 

 referring to Bolivian rocks and the Skiddaw Slate are 

 discussed. The general trend is towards the estab- 

 lishment of a metastable ternary system of white mica, 

 chlorite, and quartz by a process of molecular differ- 

 entiation : (a) Monad-oxides, type R^O, allied with 

 alumina, silica, and water (mica); (b) diad-oxides, 

 type RO, allied with alumina, ferric oxide, silica, and 

 water (chloritic matter) ; and (c) free silica (quartz). 

 In the early stages this differentiation is imperfect : 

 the mica contains iron oxides, magnesia, etc., and 

 the chloritic matter adsorbs alkalis. The identity of 

 mineral species evolving from the chloritic matter de- 

 pends partly upon the molecular ratio RjO, : RO, and 

 this in turn depends partly upon the reduction of ferric 

 oxide to ferrous oxide. The development of rutile, 

 ilmenite, epidote, etc., is probably subordinate to the 

 main trend. — W. A. Richardson': The micropetro- 

 granhv of the rock-gypsum of Nottinghamshire. A 

 wide range of structural types, including many meta- 

 morphic tvpes, are found. The evidence supports the 

 view of B. Smith that the main series is of sedi- 

 mentary origin, and that the nodular deposits ar« 



