DIFFERENT ORDERS OF SPACE UNITS 



129 



here the wind-blown snow fills the notchings of the surface at the joints.^ 

 When the cliffs seen on the Norwegian coast were too distant for ex- 

 amination of the joint system, the sags of the horizon line could still be 

 seen to recur with noteworthy uniformity, except where obscured by the 

 peculiar carving of mountain glaciers. From these observations it would 

 appear that the subdivisions in the relief are determined, at least in part, 

 by the concentration of frost work on the joints which show the widest 



Figure 5. — Effect of Frost Work 



The view shows the effect of frost work on joints with excessive weathering on more 

 favored individuals which recur at subequal intervals. Collections of snow on deeper 

 Indentations display well the structure. (After a photograph from Iceland reproduced 

 by Thoroddsen.) 



openings, and that these recur at regular intervals. Such divisions of 

 the country by joints of special importance being perceived along all 

 azimuths, it is evident that a double series at least must be present, and 

 that these are seen, first one and reciprocally the other, with varying 

 amounts of foreshortening by perspective. 



Belief Patterns in topographic Maps 

 checkerboard topography 



The accurate maps of the coastal region of Norway show the relief to 

 be ordered in a repeating pattern. Of the two orders of blocks above 

 described, the units of the higher order are grouped to form unit blocks 

 of still higher orders of magnitude (see figure 6). This striking large- 



«Th. Thoroddsen 

 p. 255. 



Lysing Islands (in the Icelandic language). Copenhagen, 1910, 



