ra 4 THE BEAUTIES OF NATURE CHAP. 
miles, the Ardennes from 50 to 25 miles, 
and the Appalachians from 153 miles to 
65! Prof. Gumbel has recently expressed 
the opinion that the main force to which 
the elevation of the Alps was due acted 
along the main axis of elevation. Exactly 
the opposite inference would seem really to 
follow from the facts. If the centre of force 
were along the axis of elevation, the result 
would, as Suess and Heim have pointed out, 
be to extend, not to compress, the strata; 
and the folds would remain quite unaccounted 
for. The suggestion of compression is on the 
contrary consistent with the main features of 
Swiss geography. The principal axis follows 
a curved line from the Maritime Alps towards 
the north-east by Mont Blanc and Monte 
Rosa and St. Gotthard to the mountains over- 
looking the Engadine. The geological strata 
follow the same direction. North of a line 
running through Chambery, Yverdun, Neu- 
chatel, Solothurn, and Olten to Waldshut on 
the Rhine are Jurassic strata; between that 
line and a second nearly parallel and running 
through Annecy, Vevey, Lucerne, Wesen, 
Oe ee ee ee 
