THE STRENGTH OF THE EARTH'S CRUST 



i6i 



all the cases. The anomaHes were not computed for greater radii. 

 The more convincing argument, however, for regional compensation 

 to at least i66 . 7 km. radius in the vicinity of Pikes Peak is the fact 

 that the algebraic difference of the anomalies between the top and 

 bottom of the mountain, stations 43 and 42, is less than one-half for 

 regional compensation to 166. 7 km. radius than for the correspond- 

 ing value given by the hypothesis of local compensation. The 

 decrease in the difference is furthermore progressive with each 



TABLE IV 



assumed widening of the zone. The result of adding the more 

 distant stations, 44 and 45, favors regional compensation more 

 markedly but is indeterminate between M and O. It would seem, 

 then, that the front range of the Rocky Mountains in Colorado is 

 upheld above the surrounding plains and parks by virtue of the 

 rigidity of the earth. 



The two stations in Arizona at 68 and 69 are well situated also 

 to test the question of local versus regional compensation, but the 



