more radical though perhaps gradual character set in. The sub¬ 
mergence of the beds having reached its limit, the beds were 
powerfully compressed in a lateral direction, folded, tilted, faulted 
and fissured. This compressure is generally attributed to the 
disturbance of the rocky envelope of the earth following upon the 
cooling and contraction of its molten interior. At the same time, 
if not due to the same cause, the rocks assumed a crystalline 
structure, the beds of carbonaceous vegetation, then probably re¬ 
sembling lignite or hardened peat, were changed into plum¬ 
baginous anthracite. The beds of clay in places became mica 
schist, the conglomerate was compacted, and its pebbles arranged 
in parallel order, and the underlying older rocks became still more 
crystalline in character. The fissures throughout the series be¬ 
came filled with veins of quartz. Numerous observations prove 
that this pressure came chiefly from two directions :—One W. NW. 
—E. SE., the other at right angles N. NE.—S. S\V., the former 
producing the great folds tending N. NE.—S. SW. parallel to 
the Appalachian range which was formed at this time, the other 
producing a series of minor folds and fissures trending W. NW. 
—E. SE. 
The folded strata were brought above water and the main out¬ 
lines of the bay and of our island were formed. The surface thus 
exposed suffered erosion by the rivers, tides and rains during a 
great lapse of time, until the glacial period set in, when they were 
subjected to still greater changes at the hands of the ice sheet, 
which by means of its enormous weight, and the stones and boul¬ 
ders frozen into its under surface, plowed out hollows, shattered 
and broke off rock masses, furrowed, grooved and polished all 
the surfaces which withstood its southward march. During the 
thawing of the glacier, a depression of the land took place fol¬ 
lowed by an elevation of 40' to 50'. To the action of the ice sheet 
and of the great stream to which it gave rise as it thawed, the fi¬ 
nal configuration of our bay and islands is mainly due. This be¬ 
comes apparent in examining a section of the bay, for the depres¬ 
sions do not always correspond to the depressions in the folds of 
the strata. The folds have been cut into. How much of this is 
due to the preglacial erosion is uncertain. The most notable in¬ 
stances of these influences are seen between High Hill Point and 
