DETERMINATION OF DEFLECTION OF LIGHT BY THE SUN'S GRAVITATIONAL FIELD. 311 



more comparable than are the images of the fainter stars. The measures of these stars 

 are given in the following table : 



The equations given by these stars are 



- 0-160d l-107e - 0-789a + /== 

 + 0-334of + 0-472e + l-336 + /= 

 + USd + 360e + 1 574a + / == 

 + 0-587d + l-099e + 0-726a +/== 

 + 0-860d + l-321e + 0-589a + /= 



The mean of (4) and (5) added to (1) gives 



0-103e - 



2-910 



Dy 3 



Dy 6 

 Dy 10 



(1) 

 (2) 

 (3) 

 (4) 

 (5) 



While the sum of (2) and (3) gives 



+ 0-682cZ + 0-832e 

 Subtracting these we get 



3-041a + 0-729e + 0-118d = Dy, + Dy 4 - l)?/ 5 - | (Dy,, 



This equation has a small coefficient for e and a very small one for d. 



Calculating the quantities on the right-hand side, assuming e to be the same for 

 all the plates, and substituting the values of d from the previous table, we find : 



0-240e = + 0-056 1 



0-240e= + 0-049 2 



0-240e = + 0-047 3 



0-240e = 4-0-059 4 



0-240e = + 0-050 5 



0-240e = + 0-059 6 



0-240e = + 0-036 7 



0-240e= +0-046 8 



a + 0-240e = + 0-035 9 



a + 0-240e = +0-048 10 



a +0-2406 = +0-045 11 



a +0-2406 = +0-059 12 



a + 0-283e= +0-026 15 



a + 0-240e = + 0-024 16 



a + 0-240e = +0-028 17 



a + 0-240e = + 0-029 18 



