SCENERY OF SWITZERLAND. 
180 
south fold lies somewhat south of the south border 
of the north fold. The fronts, so to say, of the two 
folds approach nearest at the Hausstock on the north, 
and the Kalkhorn on the south; and again (Fig. 130) 
at the Foostock from the north to the Piz Segnes on 
the south. 
The formation of the two folds was probably 
contemporaneous, though Heim considers that the 
south fold probably commenced first. 
The effect of the double fold has been to shorten 
the distance between the Walen See and the Rhine 
valley by 32 km., that is to say from 67 km. to 35.* 
The north fold is go km. long with a ma.ximum 
breadth of 16 km., the south fold 48 km. long with 
a maximum breath of 13 km. Altogether the strata 
are reversed over a surface of 1130 square km. 
But though we thus get a general idea of this 
wonderful and interesting district, there are many 
questions still to be cleared up. The commence- 
ment of the folds to the east and west are still 
obscure, and the strata are in many places so 
crumpled, contorted, crushed, and metamorphosed 
that they can scarcely be recognised. 
In many places the ridges are very sharp, and 
in the Vorab chain above Elm, in the Sernfthal, the 
* Heim, Mech, d, Gebirgshildung^ vol. i. 
