CONTENTS. 
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PAGE 
Verneuk Pan. By A. W. Eogers, Sc.D., F.R.S.S.Af. ... 79 
Gravity in South Africa. By R. A. Lehfeldt, D.Sc, F.R.S.S.AL . 83 
Effects of Uniformity and Contrast on Light. By Hermann Bohle, 
F.R.S.S.Af 127 
The Effect of the Electric Discharge on Water Vapour. By E. 
Jacot, B.A. (Plates II. III., three text-figures) .... 137 
The Absorption- Spectrum of Oxygen and a New Law of Spectra. 
By James MoiR, D.Sc, M.A., E.R.S.S.Af. . . . . .157 
Meteorology of South Africa. An Investigation into the Land and 
Sea Breezes Conditions at Port Elizabeth. By A. G. Howard, 
M.S.A. (Plate IV.) 161 
Graphical Representation of some of the Simpler Analytic Functions 
of a Complex Variable. By E. T. Littlewood, M.A., B.Sc. 
(Eleven text-figures) 173 
Upon the Fourth Order Perturbations in the Motions of Satellites III. 
and IV. of Jupiter. By R. T. A. Innes, F.R.A.S., F.R.S.S.Af. . 183 
Minutes of Proceedings ix 
List of Fellows and Members xiv 
