170 J. Brysen—Glacial Phenomena of Long Island. 
of Brooklyn was under water; and to the same cause is due the 
broken character of the north side of the island. Above Great 
Neck at Hempstead, the waters broke through the main ridge, 
carrying away the debris in front of them for several miles, forming 
the gravelly plains, as at Garden City, and making a gap clear 
through to the ocean. To this fact is due the barrenness of the 
soil, for had it not been for this, Hempstead plains would have 
been as fertile as those of Kings. The evidence of this is very 
clear, as the stones around Hempstead are all smooth and water- 
worn, and differ in this respect only from those of the drift, as the 
pebbles are formed from the same material brought from the north, 
coarse conglomerate predominating, pieces of which the writer 
found on the very summit of Harbor Hill, at Roslyn, not carried 
there by the drift, but washed up by the current, showing that the 
water at the close of the Glacial age must have stood as high as our 
highest hills, Roslyn being the highest point on Long Island. This. 
seems almost incredible ; but when we remember that the glacier 
was from ten to fifteen thousand feet in thickness, it does not seem 
impossible. It was under the glacier that these mighty torrents 
prevailed. 
Sand hills, intercalated with gravel, attest their force. River 
terraces were formed as the waters gradually subsided, and as the 
ice finally melted, a stratum of Boulder-clay was deposited on the 
top; this is evident from the fact that the stratum of clay grows 
thinner as we near the margin of these icy streams. The currents 
being strong and high until the close of the Ice age would naturally 
sweep away most of the debris that fell into them. Evidence of this 
is seen in the smooth rounded boulders found at the mouth of these 
ancient rivers, some of which, dug out of the channel at Gorvanus, 
are of the most beautiful description; the different kinds of granite 
and sandstone being polished as if by machinery. The larger 
boulders which the currents were unable to carry away may be seen 
lying at the bottom of the now dried-up streams; for when the 
present channel of the Hast River was formed, these interior rivers. 
were all drained, leaving only a swamp to mark their site, and the 
city of churches was well named “ Brucklin” by the Dutch settlers. 
of the west end of the island. In these facts it seems we have an 
explanation of all the phenomena so puzzling to scientists. 
Here on Long Island is the key to the long perplexing problem. 
It is written so plainly that, as Prof. Agassiz says, one must shut his. 
eyes if he fails to see it. 
Shells, if found at all, are at the bottom of the drift, the former 
bed of the ocean, yet Long Island is spoken of as of marine origin, 
and the wood found in the débris must, according to Dawson, have 
been brought from some island in the sea, as if no trees grew on the 
continent prior to the Glacial age. Terraces are made into sea- 
beaches where no sea existed, as the parallel roads of Glen Roy, and 
the seventeen parallel ridges south of Richmond, Mass., are laid 
down by icebergs, according to Sir Charles Lyell. How strange it is 
that some scientists will resort to far-fetched and doubtful conclusions 
