109 JOURNAL OF THE 
Piedmont plateau region it should be borne in mind that 
while the slaty belts present more favorable conditions 
for developing waterpowers, as shown in the case of 
the Yadkin and the other streams which cross the 
several belts, owing to the fact that in these belts the 
sheets of rock stand more on edge and vary more in hard- 
ness and durability, yet the streams which draw their 
supplies from the granitic and gneissic areas are more 
uniform in their flow for the reason that while the rain- 
fall in the different belts is approximately the same, the 
soils in the granitic and gneissic areas are deeper and 
more porous and serve more as a sponge for storing up 
the surplus water of rainy seasons than does the more 
shallow and compact clayey soils resulting from the decay 
of the slates. This is one of the principal causes why 
the flow is less uniform in the case of the Haw and Deep 
rivers (see map), which lie largely in the slaty belt, 
than in the case of the Yadkin and Catawba, which lie 
almost wholly in the granitic and gneissic areas. For- 
tunate it is then, that these two larger rivers have their 
headwatersin the granitic and oneissic areas, with gravel- 
ly, porous soils; and flow across the great slate belt 
after they have attained their larger proportions. 
WATERPOWER IN THE MOUNTAIN REGION. 
A glance at the accompanying small geologic map 
will show that the larger part of this region is occu- 
pied by gneissic rocks. These have for the most part a 
characteristic northeast and southwest strike, and the 
irregular sheets of rock dip beneath the surface at vary- 
ing but generally steep angles. The southern half of 
the region has along its western border an irregu- 
lar belt of bedded slates, limestones, quartzites and con- 
glomerates; and these rocks, which make up the bulk 
ot the Great Smoky mountains, have a general north- 
