INTENSITY AND DIRECTION OF THE FORCE OF GRAVITY IN INDIA. 317 



We have not at present sufficient pendulum stations to warrant definite conclusions, 

 but we can make use of those we have to test whether the observations of the 

 intensity and direction of gravity tend to corroborate one another.* The cross-section 

 in fig. 3 of Plate 14 gives the result of pendulum observations at stations on the 

 meridian of 70 30' ; the direction of gravity at these and intermediate stations is 

 shown referred to Kalitlnpur as +6" in Table IV A. for all places north of latitude 27, 

 in Table IVfi. for places near latitude 25, and in Table IVc. for all places south of 

 latitude 24. We can therefore institute the following comparisons : 



(1) The pendulum section would lead us to expect a large northerly deflection at 



Station 38, and Table IVA. shows that at this station (Dehra Dim) the 

 deflection is 29" north, f 



(2) From Station 38 to Station 24 the pendulum indicates a gradual increase in the 



density of the crust ; the plumb-lines confirm this increase in a remarkable 

 manner. 



(3) At Station 24 (Kalianpur) the pendulum indicates the existence of a greater 



amount of subjacent matter than underlies the stations on either side of it. 

 Tables I. and II. show this more clearly than the section. Now, if we look in 

 Table IVi3., we find that from Kesri to Tinsia the plumb-lines are all deflected 

 south towards Kaliiinpur, whilst if we look in Table IVc. we see that from 

 Takalkhera to Badgaon the plumb-lines are deflected north towards Kalianpur. 

 Thus the existence of an excess of matter in the crust indicated by the 

 pendulum at Kalianpur is confirmed by the action of the plumb-lines on both 

 sides of it. 



(4) The pendulum section shows a considerable excess of matter to underlie 



Stations G and 7 (Bangalore). Now, if we look at Table IVc., we see that the 

 direction of gravity is much disturbed in the neighbourhood of Bangalore. 

 At the two base-line stations near Bangalore, the deflections are northerly ; 

 sixty miles north at Bommasandra the deflection is 8" southerly. The 

 inference is that an intermediate excess of matter exists, and that a station 

 could be found north of Bangalore at which the pendulum would indicate a 

 greater excess than at Bangalore itself. (The section had to be drawn 

 from station to station, but if intermediate observations were to be taken, 

 it is certain that the maxima and minima of the section would be slightly 

 moved.) 



(5) Table I. shows that the force of gravity was below normal at all BASEVI'S 



inland stations but Calcutta ; for this reason Calcutta has hitherto been 



* It is true that the results of the old pendulum observations are not correct, but their errors are mainly 

 systematic and though affecting absolute values do not vitiate differences. Differences are sufficiently 

 accurate to justify the comparisons instituted. 



t The names of the numbered stations of the section are given in Table II. 



