Mineralogy and Geology of the White Mountains. 119 
when the granite was not in a consolidated state. Above this, 
we may observe the dike passing in full width; then sending off 
branches from the main body, including coparenily detached 
portions of granite, or separated by long narrow and broad lines 
of granite; then becoming confluent into a lesser dike, to be 
again enlarged, and subdivided into tortuous lines, or stand in 
curved plates, covering concave surfaces on the side of the gorge, 
from which the granite has flaked off, or in shoots terminating 
abruptly, or in evanescent lines, every where enclosing granite, 
and the granite in turn enclosing trap. This constantly varying 
ce of the dike and granite at different elevations, forces 
the conclusion that the granite was fissured while a tenacious 
mass, and is still united by filamentous portions running in every 
direction, and the granite and trap both reticulated, so that if it 
were possible in a given spot to remove one layer after another, of 
only a few inches in thickness, each new face would present a 
varied aspect according to the size and inclination of the portions 
intersected. 
This dike was traced as far as circumstances allowed some 
fifteen hundred feet high, till the ascent became impeded by 
a perpendicular front six feet high. The dike was visible above 
this point till a turn in the gorge, and there can be little doubt 
that it extends to the top of the mountain, and has completely 
riven itin two. The gorge is from thirty to fifty feet deep, and 
at top twenty to thirty feet across, excavated in the rock itself; its 
sides very steep, vertical, and even overhanging in some places: 
The trap is generally of a dark or blackish gray, fine grained, 
crystalline, very compact, hard, fires a little with steel, and con- 
tains no foreign minerals; another portion is light gray, and com- 
pact ; and still another, light gray, seeming like a decomposing 
earthy sandstone, filled with smooth rounded nodules of the size 
of a small pea and less, very prominent on a weathered surface, 
occasionally containing white crystalline matter, but usually 
earthy throughout, and scratch glass readily. This at the time 
was saturated with water that runs in the gorge, and the speci- 
junction Pi ie dark gray trap and granite is most aatae as if 
soldered together ; and these specimens presenting a beautiful 
contrast, may be easily obtained, as a fracture seldom occurs at 
the line of junction more readily than through the mass. 
