Chap. VI. 
INDIAN HIEROGLYPHICS. 
523 
struck me, that the reader may form a general idea of 
their character, and of the opinions I have brought for- 
ward. One of the carvings by the Gila is particularly inte- 
resting as occurring on a rock on the precipitous side of the 
lava terraces, the present position of which, half covered 
by another mass, hiding part of the carving, proves that 
the changed position of the rocks, through some natural 
phenomenon, is of later date than the figures. 
Other engravings, also taken from the lava walls along 
the Gila, have more the character of an inscription, or of 
the communication of connected thoughts, than any others 
that I saw. 
A desert covered with pebbles and fragments of granite, 
porphyry, syenite, greenstone, jasper, &c, &c, extends 
above the lava terraces, on each side of the Gila. At the 
foot of the wall the ground is so saturated with salts, pro- 
duced by the action of the atmosphere upon the volcanic 
