298 THE i3EAtJTiES OF NATURE chap. 



the Jura. Hence the main drainage runs 

 along the line from Yverdun to Neuch8,tel, 

 down the Zilil to Soleure, and then along the 

 Aar to Waldshut : the Upper Aar, the Emmen, 

 the Wiggern, the Suhr, the Wynen, the lower 

 Reuss, the Sihl, and the Limmat, besides 

 several smaller streams, running approxi- 

 mately parallel to one another north-north- 

 east, and at angles to the main axis of 

 elevation, and all joining the Aar from the 

 south, while on the north it does not receive 

 a single contributary of any importance. 



On the south side of the Alps again we 

 have the Dora Baltea, the Sesia, the Ticino, 

 the Olonna, the Adda, the Adige, etc., all 

 running south-south-east from the axis of 

 elevation to the Po. 



Indeed, the general slope of Switzerland, 

 being from the ridge of the Alps towards the 

 north, it will be observed (Fig. 42) that almost 

 all the large affluents of these rivers running 

 in longitudinal valleys fall in on the south, as, 

 for instance, those of the Isere from Albertville 

 to Grenoble, of the Rhone from its source to 

 Martigny, of the Vorder Rhine from its source 



