



1916,] The Third Indian Science Congress. xcvii 



rotation velocity were to decrease considerably now, Southern 

 India and equatorial Africa would stand out as rock protuber- 

 ances high above the ocean, and would exhibit snow and 

 laciers. 



Every year the Earth is bombarded by swarms of small 

 meteors ; is it not possible that at certain times in the distant 

 past the Earth received larger meteoric masses than in the his- 

 toric period, sufficiently large perhaps to upset the Earth's 

 equilibrium by displacing its centre of gravity. Its figure 

 would then be forced to undergo readjustments. If the Earth 

 meets a swarm of meteors in space, and if some of them ap- 

 proach within its attraction, it seems possible that almost all 

 the captured meteors may fall upon that hemisphere of the 

 Earth which first meets the swarm , whilst the other hemisphere 

 may receive very few. This would interfere with the Earth's 



balance. 



Whilst something may occur in one age to cause move- 

 ments of rock towards the pole, another cause may arise at a 

 later date that will tend to oppose those movements. Not 

 very long ago a great ice age occurred, and all Northern 

 Europe and America were buried under ice : an immense 

 volume of sea- water must then have been transferred from the 

 equatorial oceans to the north pole : this may have disturbed 



the Earth's equilibrium and have displaced its centre of 

 gravity. 



In the same ice age the Himalaya and Tibet became 

 capped with greater masses of snow and ice than they now 

 carry. The glaciers that now end at 12,000 or 13,000 feet de- 

 scended in the ice age to 5,000 feet. This increase in the 

 weight of the Himalaya was an additional deformation of the 



Earth's figure of equlibrium. 



I suggest to you that the great mountains from China to 

 France have been due, firstly, to a line of fracture from Bengal 

 to Sicily, and, secondly, to adjustments of the Earth's figure. 



The Andes trend north and south ; they are of the same 

 age as the Himalaya. If the Earth's figure is undergoing 

 deformation, and a rent is torn in the crust along an east to 

 west line under the influence of forces seeking to restore equili- 

 brium, it seems possible that secondary cracks might occur and 

 that the Andes may be the result of one of them. The Andes 

 are shown to scale on this chart : you will see that in length 

 they are not very much less than the China to France ranges, 

 but in breadth and mass they are relatively insignificant. 



You will notice from this chart (8) the peculiar curve of 

 the northern Tibetan border, concave on the east, convex on 

 the west. This sinuous curve is reproduced in the north of 

 Persia, and again in the Carpathians. The Persian ranges all 

 have a trend from south-east to north-west except that the 

 Caspian subsidence seems to have pushed rudely in from the 



