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GEAYITY IN SOUTH AFEICA. 
By R. a. Lehfeldt, D.Sc, RR.S.S.Af. 
(Read March 16, 1910.) 
Shortly after arriving in Johannesburg, the author made a rough de- 
termination of as that quantity was at the time unknown. The 
result, 9*786 metres/sec.^, was published in the Philosophical Magazine, 
Nov., 1906. As the South African tableland is one of the only two really 
large tablelands in the world — the other being Tibet — a certain geophysical 
interest attaches to gravity measurements there, and it was hoped that 
they might be continued with proper apparatus. The author applied to 
the hydrographical department of the Austro-Hungarian Government, which 
has long shown itself interested in the matter, and the Director very 
courteously and promptly lent the author three pendulums of the well- 
known Sterneck pattern, such as had been used for gravity measurements 
at coast stations by officers of the Austrian navy, together with subsidiary 
apparatus. The author desires to convey his thanks to the Austro- 
Hungarian Government for this loan, and to others for incidental assistance 
rendered during the observations — the South African railways for transport 
facilities, the Post Office for the use of telephone lines, and especially to 
Mr. R. T. A. Innes, Director of the Transvaal Observatory; Mr. Hough, of 
the Royal Observatory, Cape of Good Hope ; and Capt. Lacerda, of the 
Observatory, Lourengo Marques. 
Although the method of measurement is well known, it has not always 
been easy to find satisfactory conditions for observation in a new country. 
This, coupled with the limitations of time at the disposal of the author — 
vacations only being available — has resulted in but a small number of 
measurements being carried out. These, however, throw some light on 
the problem of the tableland, and it is therefore thought worth while to 
publish them without waiting for more. 
