GLACIAL DRIFT. 275 



hill towns. There is a multitude of large boulders in Franconia opposite the Valley 

 house. They cover acres of land, some of them being 20 feet long. On top of Flume 

 mountain is a boulder 25 feet long, 15 wide, and 12 high. Near Fifield's house in 

 Thornton, on the east side of the Pemigewasset, is a boulder averaging 30 feet in each 

 of the three dimensions. At the south part of Rattlesnake hill, Concord, is an uncom- 

 mon amount of boulders of granite, whose dispersion must have been due to the ice. 

 Near Gilmanton Iron Works, I found boulders of quartzite precisely like that of the 

 Coos group from Moose mountain, Hanover, to Cuba, etc., 6 by 3 by 3 feet. The dis- 

 tance from here to the Cuba range, north-west, is nearly 50 miles. We have preserved 

 samples of glaciated stones taken from the drift overlying the inter-glacial clay at the 

 Weirs and in New Hampton. A block at Weirs is 6 feet square. On the Isles of 

 Shoals are boulders that have come from the main land. On the south part of Cho- 

 corua are granite boulders 4 feet long, and bits of porphyritic gneiss 18 inches across. 

 On the west side of Kimball hill, in the edge of Whitefield, are boulders like the Beth- 

 lehem gneiss, perhaps brought there by the glacier described by Agassiz. There is 

 also a moraine of the Ammonoosuc glacier, not mentioned above, below Bethlehem 

 Hollow. In North Lisbon are bits of Albany granite, 5 inches in diameter, brought 

 down by the glacier. 



In Brookfield are numerous boulders of a siliceous limestone, such as crop out in a 

 single ledge in Wakefield, and abundantly in Newfield, Maine. These boulders are 

 very numerous in Newfield, and they occur on Copp's Hill, Wakefield. Observations 

 do not demonstrate the absence of ledges of this limestone in our state, but the ques- 

 tion is raised whether these blocks have not been transported in a south-west direction. 

 There is a probability that, when studied carefully, a south-west distribution of boulders 

 will be indicated for Oxford and Carroll counties. 



Boulders in Sand. The Portland & Ogdensburg Railway has made 

 considerable excavation in the surface deposits between the Notch and 

 Fabyan's, which illustrates the nature of the till and modified drift. At 

 the Crawford house is the first excavation, 1,320 feet long and 20 feet 

 deep at the middle, made through one of the river moraines described 

 on a previous page. The material came down Cascade brook from the 

 west. It is entirely stratified, though the materials are coarse, as is 

 shown in our heliotype illustration ef it. The swell of land crowned by 

 the Crawford house is made by this gravel deposit meeting the till of the 

 east side of the valley. 



After proceeding 864 feet beyond the gravel cut, there are excavations, 

 mostly on the upper side of the track in an ice drift, extending for 408 

 feet, where the nearest point to the Saw-mill pond is reached; then there 

 is another small cut through the same material for 216 feet. After this 



