25(> 



THORODDSEN 



mountains-sides is saturated with water from melting snow during 

 spring, and slides slowly downwards; very often gravel and clay is 

 by this arranged in bands down the slopes. Below large snow-drifts 

 which persist till far into summer, or during the whole of summer^ 

 there is always water which soaks into the soil, and upon many 

 mountain-sides, slow-flowing mud-streams are formed, which in shape 

 and movement recall small glaciers. In other places the flowing 



Fig. 17. An old Tun. K.jos near Reykjavik. (Phot. A. HesselboJ 



soil forms small terraces, which are partially transformed into rows 

 of knolls overgrown with plants. Sometimes the soil is loosened 

 from the solid rock, or slides upon the ice of the subsoil; some- 

 times clayey streams flow down into depressions and valleys, and 

 occasionally fragments of greensward, which had been resting upon 

 a saturated substratum of sand and clay, are loosened. Frequently 

 it can also be seen how water, flowing upon the ice of the subsoil 

 down the slope, undermines the soil so that large pieces of green- 

 sward are put into motion, give way, and are torn asunder. It may 

 also happen, where there is a thick layer of loose soil, that the 



