RIVER SYSTEMS OF NEW HAMPSHIRE. 319 



is divided into successive falls and rapids, separated by only a few miles 

 from each other, along this entire distance. This river leaves the state 

 at a height of 200 feet above sea. 



The water-power of this river at one of its principal falls, about two 

 miles north of White River Junction, is illustrated by the annexed plate, 

 prepared by Mr. J. T. Woodbury, of the Thayer Department of Civil 

 Engineering, Dartmouth college. He states that the amount of flow of 

 the Connecticut at Ledyard bridge on May 4, 1874, was 3,498,636 gallons 

 per minute, and estimates that in the driest season the flow might be 

 reduced to one eighth of this amount. A dam 10.8 feet above present 

 surface at the head of the falls, one fourth mile above the paper mill, 

 flows back to this bridge, and gives a fall of 31^ feet at a distance of half 

 a mile. A canal now exists on the New Hampshire side, formerly used 

 for the river navigation, in which a depth of ten feet is secured by this 

 dam. This canal passes through 450 feet of hornblende schist, and 

 would require enlargement. On the Vermont side a canal can be con 

 structed of any desired length, passing through the common terrace 

 formation of the river. 



East and south-east from the point where the Connecticut river enters 

 its lower valley is the extended mountain region of New Hampshire. 

 From the wide interval on the Lower Ammonoosuc river, seven miles 

 south-west from Mt. Washington, to the place where that river empties 

 into the Connecticut, is a descent of about 1 1 50 feet The lowest point 

 of the water-shed, dividing the waters of the Lower Ammonoosuc from 

 those of the Saco, has an elevation of over 1900 feet above the sea. 

 Here is an area of 1300 square miles, or one seventh of the area of the 

 whole state, thickly set with mountains which vary in height from 3000 

 to 6000 feet above the level of the sea, the bottoms of its valleys varying 

 from 1000 to 2000 feet in altitude. These mountains constitute a group 

 in the general form of an oblique parallelogram, having its corners in 

 Bethlehem, Shelburne, Conway, and Warren. Of course any such rigid 

 boundaries must be imperfect; the south line should be bent farther 

 south at the middle to include the high mountains of Sandwich; the 

 mountains of Orford, and those on the opposite side of the river in Ver 

 mont, seem to be the south-western extension of this central group, 

 while in a north-eastern direction it is continued into the state of Maine. 



