164 Trans. Acad. Sci. of St. Louis. 



would be the common potential of the two bodies, under 

 the conditions assumed in Eq. (1), when their attraction 

 for each other is a maximum. 



The gravitation constant has been determined by meth- 

 ods, which it was assumed made it unnecessary to con- 

 sider the electrical condition of the two bodies. Never- 

 theless the results have been very unsatisfactory. In 

 his presidential address before the American Mathemati- 

 cal Society in December, 1899, R. S. Woodward referred 

 to this constant as being one of the constants of the solar 

 system whose determination was in a most unsatisfac- 

 tory condition, as regards precision. 2 



If the masses are capable of acting upon each other 

 electrically, and the final term in Eq. (1) is omitted, that 

 equation might be written. 



In this equation an error of x per cent, in the value of 

 K would result. By (1) and (2). 



T , 4 t> r> ^ \/Kx 



If V is measured in volts, 



V=-^0'rrR 1 R 2 pVKx (3) 



For purposes of illustration assume that K=6.6576 X 

 10~ 8 and that R x = lOx, R 2 =l and p = 11.35 ; then 



V = 3.68V * 



If the common potential of the two spheres differs 

 from absolute zero by 3.68 volts, the value of K would 

 be in error by one per cent of the above value, which is 

 that of Boys, unless adequate means are taken to elim- 

 inate the effects represented by the final term of Eq. (1). 



If V were ± 8.23 volts an error of five per cent would 

 result. If V were ± 36.8 volts, the two spheres would 



2 Bulletin Am. Math. Soc. II 6:153. 



