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LIEUT.-COLONEL S. G. BURRARD ON THE 



at the standard stations of Europe and as observed in India ; the determination of the 

 absolute value of the force of gravity did not and does not form any part of the 

 operations. 



The values of gravity exhibited in Table I. are taken from Professor HELMERT'S 

 Report to the International Geodetic Conference, which was held at Paris in 1900. 



TABLE I. -BASEVI'S and HEAVISIDE'S Results Expressed in Dynes. 



EXPLANATION OP SYMBOLS EMPLOYED. 

 For fuller details as to the manner in whirl* these numbers are derived, see the explanation of Table II. 



/ 2H\ /H + R\ 2 



?V' + ~K I ''ppresonts g \ % / ; the third place of decimals in expressions for gravity at high stations may differ by two or 



three units according to the form of the formula used. 



g = the value of the force of gravity as observed at the height H, the value at Kew being assumed 981 -200. 

 g' = the observed value of gravity reduced to an infinite horizontal plain of height H. 

 g' - g = topographical correction due to the irregular distribution of mass in the vicinity of the station. 

 g a = the observed value of gravity reduced to sea-level for height only. 



g a " = the observed value of gravity reduced to sea-level both for height and for mass above sea-level. 



y = the theoretical value of gravity computed from HKLMERT'S formula of 1884, namely, 978 -000 eentims. (1 + -005310 sin" (>). 

 9o" - Yo = load variation of gravity from the normal, as computed by BOUQUKR, and as used for the determination of mountain-compensation. 

 ?o - Yo = 'oca' variation of gravity, as used by HELMKST in his determination of the Figure of the Garth. 



