I 



THE 



SOUTH AFRICAN JOUR|^; 

 OF SCIENCE; 



COMPRISING THE REPORT OF THE 



SOUTH AFRICAN ASSOCIATIOfJ 



FOR THE 



ADVANCEMENT OF SCIENCE. 



I 916. 



MARITZBURG. 



OFFICERS : 1016-1917. 



PRESIDENT, 

 Professor J. Orr, B.Sc, M.I.C.E. 



VICE-PRESIDENTS. 



A. H. Reid, F.R.I.B.A., F.R.San.I. Prof. E. H. L. Schwarz. A.R.C.S., F.G.S. 



^Professor W. N. Roseveare, M.A. H. E. Wood, M.Sc, F.R.Met.S. 



HON. GENERAL SECRETARIES. 

 C. F. JuRiTz, M.A., D.Sc, F.I.C., Agricultural Chemical Research Laboratory, Capetown. 

 ■•J. A. FooTE, F.G.S., F.E.I. S., Commercial High School, Plein Street, Johannesburg. 



HON. GENERAL TREASURER. 

 A, Walsh, P.O. Box 39, Capetown. 



ASSISTANT GENERAL SECRETARY. 



H. Tucker-, Cape of Good Hope Savings Bank Buildings, St. George's Street, Capetown. 

 P.O. Box 1497. (Telegraphic Address : " Scientific") 



EDITOR OF TRANSACTIONS. 

 Dr. C. F. Juritz. 



'/OL XIII. FEBRUARY, 1917. NO. 7. 



CAPE TOWN. 



PUBLISHED BY THE ASSOCIATION 



1917. [Pri«e 2s. 



