VOLCANOES 333 
crater, but very often from fissures in the side (Fig. 199). 
It emerges as a liquid rock, glowing brightly and flow- 
ing with rapidity (Fig. 200); but soon a crust forms 
COVERMME Nw, 
tie teres 20 
abe 
Fie. 199. 
Mauna Loa in Hawaii, showing lava flows (the black portions) which started 
from fissures in the side of the cone. 
upon its surface, and then its movement is retarded. As 
it proceeds on its course, the crust breaks, and sometimes 
this makes the lava flow so roughened by loose, angular 
