94 Applications of the Igneous Theory of the Earth. 



at least, a consequejice of the tides which must prevail in the 

 central fluid, if the geological theory be true. It is quite mani- 

 fest that the undulations of the earth's crust would produce a 

 regular ebbing and flowing of the sea, without reference to the 

 direct action of the sun and moon on the waters of the ocean. 

 While a line of coast is rising to its maximum height, the oceanic 

 tide is ebbing towards low water mark ; and when the coast falls 

 to its lowest position, the oceanic tide is at flood. 



If this modification of the Newtonian theory of the tides be 

 founded in truth, it is but fair of course to expect, that in its ap- 

 plications it will be found to explain facts which have admitted 

 of no satisfactory solution hitherto. By way of illustration, I 

 will state one of these applications. On the line of our coast 

 generally the high tides are from four to six feet above the level 

 of low water. Proceeding however along the coast east of the 

 Piscataqua, we find a tide of eight or nine feet at the mouth of 

 the Kennebec; of twelve or fifteen at the Penobscot; of twenty 

 or twenty five at Passamaquoddy ; while at the eastern extremity 

 of the Bay of Fundy, the rise is from forty to sixty feet. Now 

 I would ask whether this phenomenon is at all reconcilable with 

 the hypothesis that the bed of the ocean is immovable. Why 

 should the tides in the Delaware and Chesapeake bays become 

 less and less as we leave the open sea, while the rise in the Bay 

 of Fundy increases to this extraordinary degree as we proceed 

 inland ? 



Let us apply the geological theory to the solution of this ques- 

 tion. It is very generally true that the slope, which by dipping 

 below the surface of the ocean forms a line of coast, has its upper 

 termination in a range of mountains parallel to the coast. Thus 

 it is with the eastern slope of the Alleghanies forming our Atlan- 

 tic coast. It is obvious from the bare statement, that in this and 

 like cases, the play of the fragment of the earth's crust constitu- 

 ting said slope must be such, that the tides in bays and estuaries 

 will diminish as we proceed inland. A difl'erent geological ar- 

 rangement prevails in New England, the hne of coast being 

 nearly perpendicular to the mountain ranges. It is obvious, then, 

 on inspection of the map, that the undulations of that fragment 

 which embosoms the Bay of Fundy would be likely to be such 

 as alternately to elevate and depress the eastern extremity of the 

 bay more than any part of the line of coast west of it. A strong 



