IV Contents. 
PAGE 
A Further Note on the Diurnal Variation of Level at 
KiMBERLEY. By J. E. SuTTON 73 
Verneuk Pan. By A. W. Rogers . . . . . .79 
Gravity in South Africa. By R. A. Lehfeldt ... 83 
Effects of Uniformity and Contrast on Light. By 
Hermann Bohle 127 
The Effect of the Electric Discharge on Water Vapour. 
By E. Jacot. (Plates ii., iii., three text figures) . . 137 
The Absorption-Spectrum of Oxygen and a New Law of 
Spectra. By James Moir 157 
Meteorology of South Africa. An Investigation into the 
Land and Sea Breezes Conditions at Port Elizabeth. 
By A. G. Howard. (Plate iv.) 161 
Graphical Representation of some of the Simpler 
Analytic Functions of a Complex Variable. By E. T. 
LiTTLEWooD. (Eleven text fi-gures). . . . . 173 
Upon the Fourth Order Perturbations in the Motions 
OF Satellites III. and IV. of Jupiter. By R. T. A. 
Innes 183 
Sylvester's and other Unisignants. By Thomas Muir . 187 
Sylvester's Axisymmetrtc Unisignant. By Thomas Muir . 197 
Colloidal Gold and "Purple of Cassius." Ry James Moir 203 
Some Remarkable Oxidation-Products of Benzidine. By 
James Moir 205 
Preliminary Note on the Meteorites in the Bloemfontein 
Museum. By W. A. Douglas Rudge. (With Plates v., 
vi., vii. and ten text figures) ...... 211 
The Funeral Ceremonies of the Hottentots. By C. Leo 
Biden and Rev. H. Kling 223 
Photography an Aid to Astronomy. Presidential Address. 
By S. S. Hough . .227 
