650 



these. For example : an excess of density amounting only to 

 part, extending through a circuit of about 120 miles around the 

 mid-point of the whole arc between Kaliana and Damargida (and 

 therefore not far from Kalianpur), and to a depth of about 200 miles, 

 will produce this effect, and make the calculated deflections from the 

 three causes the mountains, the ocean, and this hidden cause below 

 exactly accord with the observed errors in the astronomical ampli- 

 tudes. 



(7) The resulting total deflections at Kaliana, Kalianpur, and Da- 

 margida, arising from the three causes, are 2 6"* 29, 21 "'05, and 

 24"-84 : these make the two astronomical amplitudes, the one 5"' 24 

 smaller, and the other 3" '79 larger than the geodetic amplitudes, 

 the error brought to light by Colonel Everest. 



(8) No error can arise in the mapping of India by using the geo- 

 detic measurements. But the position of any places put into the map 

 thus formed, the latitudes of which are determined from observations 

 of the sun or any other heavenly body, will be wrong by the total 

 amount of the deflection at those places, amounting in the three cases 

 above to as much as half a mile. 



