Minutes of Proceedings. vii 



Government Entomologist, O.E.O., by J. Lyle and L. Peringuey; 

 P. C. Keytel, Cape Town, by L. Peringuey and J. D. F. Gil- 

 christ. 



Miss Inez Stebbins, B.A., and Mr. E. E. Galpin, F.L.S., were 

 elected ordinary members. 



Mr. E. Hutchins spoke at length in favour of the adoption in 

 the Cape Colony of the Metric System, and it was resolved that 

 " a representative committee of the Philosophical Society wait as 

 a deputation upon the Honourable the Premier to urge the in- 

 troduction of a Bill to legalise the Metric System of weights and 

 measures, and to provide for the compulsory adoption of the System 

 on it being adopted by the British Parliament." 



The following paper was read : — 



" Some Eesults of Observations made with a Black Bulb Ther- 

 mometer in vacuo," by J. B. Sutton, M.A., F.B.Met.S. 



The object of this investigation is chiefly to ascertain some of 

 the effects of various meteorological influences upon the indications 

 of a black bulb thermometer in vacuo at Kimberley. The highest 

 temperature observed during the seven years 1897-1903 was 

 170.5° ; the annual average is almost 138° ; the highest monthly 

 mean is 153-3°, in December; the lowest 118-8°, in June 

 and July. Days of high temperature in the sun are often dusty. 

 A comparative investigation of the different meteorological elements 

 shows that the highest temperatures in the sun occur when the 

 sky is about half clouded. When the sky is clear, the excess 

 temperature in the sun above that in the shade decreases as the 

 quantity of aqueous vapour in the air increases. It also increases as 

 the humidity increases. From which superficially antagonistic facts 

 the author draws the conclusion that while the aqueous vapour 

 absorbs the solar heat, the return terrestrial radiation is intercepted 

 to an extent dependent upon the humidity of the air. The results 

 obtained for Kimberley admit of a satisfactory comparison with 

 those obtained in the Himalayas and elsewhere. The theory of 

 Tyndall based upon the absorbing properties of aqueous vapour, 

 and that of S. Arrhenius based upon the absorbing properties of 

 carbonic acid are also considered. 



Ordinary Monthly Meeting. 

 March 29, 1905. 

 Dr. J. D. F. Gilchrist, President, in the Chair. 

 The following nominations were made : Messrs. J. Cornish 

 Bowden, of Cape Town, by Mr. E. Hutchins and Professor H. 



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