PHYSICAL HISTORY OF NEW HAMPSHIRE. 527 



The Labrador Period. 



Let us now consider the main topographical features of the area above 

 water at the commencement of the Labrador Period. From some un- 

 known spot in Maine, the country rises to the Mt. Washington range in 

 New Hampshire. These peaks probably did not rise so high as at pres- 

 ent above the water. The range continued southerly through New 

 England, spreading out broadly about the Winnipiseogee region. West- 

 ward the fundamental ridge of the Green Mountains stretches its length 

 along, passing southerly to form the New York and New Jersey high- 

 lands. Between the White and Green ranges lies the long, shallow 

 island from Essex county, Vt, to Massachusetts, on the west side of 

 the present Connecticut valley. The land on the two sides of the Con- 

 necticut nearly unites along the north Massachusetts line, while the 

 ocean broadens and deepens northerly towards Canada. 



In consequence of the strain exerted upon the infant continent by 

 lateral pressure, there may have been a break in the strata along the 

 upper Saco valley, say above Sawyer's river. The result would be the 

 upthrow of the White Mountains from Mt. Webster to Mt. Madison, and 

 the settling down of a considerable tract of land to the west of the 

 Saco. There would result, therefore, a depression or hydrographic 

 basin over a part of the White Mountain area, with these limits : 

 bounded easterly by the Washington range, the Carter mountains and 

 their foot-hills in Bean's Purchase, Jackson, and almost by the Maine 

 line ; southerly, by the foundation ridge of the Chocorua range between 

 Conway and Black mountain in Sandwich ; westerly, by the Moosilauke- 

 Kinsman range; northerly, by the gneiss in Bethlehem and Cherry 

 mountain in Carroll. Corresponding depressions, not necessarily pro- 

 duced by a sinking of the land, appear in Kilkenny, Stark, Columbia, 



claimed the merit of having previously recognized the rocks as older than the Silurian, but had not in mind any 

 definite place for them. I remember my father, in conversation, once expressed to me his conviction that the 

 New England rocks would prove to belong to a system distinct from anything then known, and of about the age 

 of the Cambrian; and I also recollect expressing emphatically a similar opinion at the Chicago meeting of the 

 American Association for the Advancement of Science in 1S68; but these surmises were not developed into 

 reasonable theories by hard study. Neither of us could claim the credit of first describing this system in the 

 full sense of the term, any more than my father could claim the invention of the telegraph ; for, in a popular 

 lecture upon galvanism, delivered at Newburyport, Mass., some years before Prof. Morse's discoveries, he 

 declared his belief that, by means of galvanic electricity, people would ere long be able to communicate with 

 each other instantaneously at stations many miles apart. These surmises were all creditable, but did not lead 

 to the actual discoveries. 



