MODIFIED DRIFT ALONG MERRIMACK RIVER. 8 1 



the high water of spring, forming the only extensive intervals on this 

 river south of Plymouth. These are from a half mile to one mile wide, 

 their fertility being in marked contrast with the barrenness of the 

 "pine plains." A fine view may be obtained in Canterbury and Concord 

 from the edge of these plains, whose high bluffs descend abruptly a hun- 

 dred feet, overlooking the level bottom-lands and the windings of the 

 river for miles north and south. In other parts of its course the river is 

 confined between terraces, which prevent an irregular route. Its mean- 

 dering course here was signified by the aboriginal name Pcuacooky or 

 crooked place, which was applied to the south part of this territory. 



Ancient river-beds are indicated at many places by shallow ponds, 

 which lie in long and frequently curved depressions of the interval, often 

 near the foot of the higher terraces, and but slightly elevated above the 

 river. One of these is seen on the east side of the railroad, a mile south 

 of Boscawen depot ; one lies on each side of the river just south of Sugar 

 Ball bluff, near Concord ; and others occur east of the south part of the 

 city; but the largest and most interesting is Horseshoe pond, at the 

 north end of the city, which is shaped like a crescent, being a half mile 

 long, nearly as wide as the present channel, and six feet above the ordi- 

 nary height of the river. This pond is crossed by the Northern Railroad. 

 Its middle portion lies at the foot of a higher terrace, against which 

 the river once swept its full current. The nearest point of the present 

 channel is a half mile distant at the north, where the river bends and 

 now directs its current against Sugar Ball bluff, a mile and a half north- 

 east from Horseshoe pond. The date of these changes cannot be stated, 

 except that it was before the first settlement here, 150 years ago. 



Recent Changes of Merrimack River in Concord. 



Dr. WiHiam Prescott, of Concord, in 1853 collected dates and measure- 

 ments of many remarkable changes in the channel of Merrimack river 

 which had taken place since a careful survey of this portion was first 

 made in 1804.* From this record it appears that below Federal bridge, 



* Collections of N. H . Historical Society , vol. vii. At the time of publication of this volume, in 1863, a state- 

 ment was added describing subsequent changes to that date. 



In the same volume is also found a valuable address on "The Valley of Merrimack," by Joseph B. Walker, 

 Esq., describing its physical features, and recounting its earlier and later history. 



VOL. IIL 1 1 



