GLACIAL DRIFT, 265 



hood of Pawtuckaway mountain, and found a very formidable array of 

 giant fragments superior to anything else described elsewhere. The 

 celebrated Picrre-a-bot of the Jura contains about 40,000 cubic feet, 

 weighing 3,000 tons ; the Green Mountain Giant of Whitingham, Ver- 

 mont, has the same cubical contents ; the one formerly existing at Fall 

 River, Mass., now destroyed, is estimated to have weighed 5,400 tons. 

 The Churchill rock of Nottingham, shown in a heliotype at the begin- 

 ning of this chapter, measures 62 feet long by 40 wide, and is estimated 

 at 40 feet high. Making liberal allowances for irregularities in its 

 dimensions, it contains over 75,000 cubic feet, weighs 6,000 tons, and 

 is therefore nearly double the size of the Jurassic and Vermont exam- 

 ples. Bingham's rock at Smuggler's notch in Vermont is larger, but is 

 so connected with a ledge as not to be properly esteemed an erratic. 

 The Swiss example has been transported much farther than either of 

 the New England boulders. 



Churchill rock is on the south side of north Pawtuckaway. It lies in 

 a valley not shown on our map by contours, starting at the middle of the 

 Deerfield and Nottingham line where it passes over this peak, and point- 

 ing east to Round pond, made a part of Pawtuckaway pond upon the 

 county map. This valley is half a mile long, and displays a very remark- 

 able lot of large boulders and moraines. The commencement of the 

 valley is a narrow notch in the sienite of the mountain, full 200 feet deep 

 and narrow. The boulders seem to have been detached from the cliffs on 

 either side of the notch, and then transported by the ice, perhaps, or local 

 glacier, eastwardly. Within a few rods of the starting-point are several 

 large blocks, worthy of special measurement anywhere except in their 

 company. About an eighth of a mile down, too far to allow of their 

 accumulation by gravity, are six large boulders close together, each one 

 averaging 30,000-35,000 cubic feet. A little beyond them is Chase 

 rock, 40 feet long, 40 feet high, and 30 feet wide. About a quarter of a 

 mile or a little less from the starting-point is Churchill rock, and close 

 by it two others, one estimated as equal to 30 feet in each direction, — 

 27,000 cubic feet, — and the other ten feet longer, with the same breadth 

 and height, or 36,000 cubit feet. On climbing the mountain north of 

 Churchill rock, some large blocks are seen, which have been severed 

 from connection with the ledge; one of them 50 feet long, slab-like in 



