THE SUPPORT OF THE HIMALAYAS. 115 



with each other, where, in other words, the anomaly of gravity 

 should be zero, proper allowance being made for the effect of com- 

 pensation. Towards the outer edge of the hills the defect of com- 

 pensation diminishes and the anomaly must ultimately become 

 zero once more. 



A variation of this kind in the adjustment between topography 

 and compensation, or between load and support, is with difficulty 

 intelligible, except on the supposition of a support of the range by 

 notation, and certainly finds easiest expression in terms of that 

 hypothesis. In the centre of the range the downward protuberance 

 of the crust is over-developed and there is an excess of buoyancy, 

 tending to make the range rise, the excess of load in the outer hills 

 would then be an indication that such rise has taken place, carrying 

 with it the outer hills, till the load thrown on the central tract 

 became large enough to check the further uplift and leave the main 

 range at a lower elevation than that which would result from the 

 protuberance beneath it, while, on the flank of this central tract, 

 the outer hills are upraised beyond the height which they would 

 attain by the effect of the support immediately below them. The 

 general distribution of the stresses set up in the mountain range, 

 by this want of adjustment between load and support, would be 

 as shown by the arrows in fis 8 : in this diagram the points 

 represent the points at which there is a complete adjustment of the 



^^-L-V . 



& — f ° * -r -i- ° 



Fig. 8. 



* 



Yig. 8. — To illustrate the adjustment between topography and compensa- 

 tion in the Himalayas. In the central region, to the left of the diagram, 

 the compensation is in excess of the load, producing an upward stress, as 

 indicated by the arrows ; in the outer region compensation is in defect, and 

 there is a downward stress. The firm line represents the actual contour 

 of the ground, the dotted line, that which it would have if the adjustment 

 between topography and compensation, of load and support, were everywhere 

 exact and complete. 



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