276 SURFACE GEOLOGY. 
is a fill of 120 feet. Then follows the cut figured in our heliotype, with 
the title /ce-drift over sand printed on a railroad tie. It is a compact, 
unstratified mass of rubbish, the stones consisting mainly of the Mont- 
alban granites and schists common in the neighborhood, overlying layers 
of sand, as shown in the illustration. The material appears to conform 
to the surface of the ground, being just as thick in the depression as over 
the elevations. This earth is evidently some form of ice accumulation; 
it is not water-worn gravel, nor does it correspond to either of the tills. 
It approaches nearer to the coarse gravel at the Crawford house than to 
any other class of deposits known in the state, but is unlike that, in the 
common absence of stratification and the angularity of the fragments. 
Its association with the sand about to be described may intimate the 
presence of a mass of ice in the neighborhood in the time of local gla- 
ciation. 
The rest of the cut just entered into extends for 336 feet. It is com- 
posed of sand, with some large stones in it, underlying the angular drift, 
as seen in the illustration. The strata dip southerly underneath the ice 
drift, and at the north end of the cut they dip northerly to correspond 
with the depression of the surface, 120 feet wide, crossed by the railroad 
upon an embankment. Next is another cut in the sand 264 feet long, 
showing boulders in it, and depressions to correspond with the surface 
of the ground. After an embankment 528 feet Jong, succeeds another 
cut in the sand of 384 feet length. From a point in this excavation, 
about 4,300 feet north of the Crawford station, was taken the heliotype 
illustration entitled Boulder in sand. The fragment may be six feet 
through, composed of bright granite as fresh as if uncovered yesterday, 
and of the same character with the adjacent ledges. Horizontal strata 
of sand underlie it, while the layers are slightly irregular about it, as 
would naturally result from the varying velocity of the current striking 
against the stone. The layers above are regular, and conformable with 
those beneath. This is therefore a clear case of a mass of stone too large 
to have been pushed by the current of water, nevertheless brought to 
this spot by some agent and dropped as readily as if it were a grain of 
sand. There must have been water deep enough to float ice carrying 
this stone upon it; and owing to a change in the equilibrium of the berg 
at this point, the granite fell to the bottom, and lies in a condition of 
