50 THE ISLAND OF NANTUCKET. 



that each of these eras covered an enormous period of 

 time, each period counted perhaps by millions of 

 years. During all this vast portion of the past, Nan- 

 tucket was not in existence. The measureless ages of 

 the tertiary period rolled on and came to an end, and 

 still there was no Nantucket. So .that the island 

 which holds the graves of our ancestors is geologi- 

 cally of recent formation. 



Subsequently to the tertiary period, came the era 

 of what is called the drift, or the glacial period. 

 At this time our continent was covered with ex- 

 panses of ice, vast in thickness, enormous in extent, 

 and spreading from the north as far south as a line 

 running through New Jersey, Maryland, West Vir- 

 ginia, and Southern Ohio. At that period the south- 

 ern coast of New England did not lie where it is now, 

 but very far to the south. The Hudson River contin- 

 ued southerly, between its banks, for some eighty 

 miles below where its present mouth is. The Housa- 

 tonic was at that time not an independent river, but a 

 mere branch of the Hudson, flowing into it through 

 what is now the channel of the East River. And the 

 Connecticut emptied into the sea some seventy miles 

 south of its present mouth at Saybrook. The submer- 

 gence of all this vast extent of land, which once lay 

 at the south of Long and Block Islands, Martha's 

 Vineyard, and Nantucket, must have been compara- 

 tively recent, and long after Nantucket was formed. It 

 was upon this extensive tract of land, then above the 

 level of the sea, that what has since become the line 

 of islands from Nantucket at the east to Staten 

 Island at the west was deposited ; at first as mere 



