374 Topographical Phenomena tn Indiana. [April, 
lateral push of freezing. A careful analysis of its process will 
show that it can have but little lateral push on level, or even much 
FIG. 5. 
on inclined ground, The first freeze is a thin crust on top, n 
thicker than paper (and about as powerless as paper), d 
thickens downward as the freeze goes on. The next oaee 
freeze below adds nothing to the lateral force of the m 
does the next, and the next. The only force freezing a E 
the ground is an uplift. There are no cracks in frozen oul 
we find in thick ice, which clearly shows that the vey ot 
fact of much lateral expansion in the under freeze of ice “ae | 
apply at all to frozen ground. Cellar and other walls ee . 
pushed in by freezing for the plainest reason. The freeze of 
on the face of the wall, extends back through it to the ground q 
that the uplift, a 4 in Fig. 6, becomes a side push, 4 £. E 
os & 
Tera 
iF rit ree 
SSS 
pa, eae z 
—— OSS 
Fic, 6. 
. . i a 
This inpush from a freeze never occurs Wh 
warm, but the retain or guard wall of an outside > ay salle 
other outdoor walls, are often thus pushed. eon 
that the different slopes of the north and south 
