12 ‘ SURFACE GEOLOGY. 
slope was to the south. In New Hampshire, the portion of the Contoo- 
cook valley which extends through Hillsborough county was thus occu- 
pied by a lake during a large part of the Champlain period. 
Kames. The oldest of our deposits of modified drift are long ridges or 
intermixed short ridges and mounds, composed of very coarse water-worn 
gravel, or of alternate layers of gravel and sand irregularly bedded, a sec- 
tion of which shows an arched or anticlinal stratification. Wherever the 
ordinary fine alluvium also occurs, it overlies, or in part covers, these 
deposits. Similar ridges of gravel have been often described by European 
geologists, under the various names of Kames in Scotland, Eskers in Ire- 
land, and Asar in Sweden. The first of these names will be adopted in 
this report. They have also been described by geologists in many por- 
tions of the northern United States. In New Hampshire, kames are of 
frequent occurrence, sometimes a single one extending in a very steep, 
narrow ridge for miles along the lowest portion of a valley, or elsewhere 
short and several parallel to each other, or in very irregular mounds and 
ridges, with hollows enclosing small ponds. Their position is generally 
along the middle or lowest part of the valleys, which are bordered by high 
ranges of hills; but in the south-east part of the state, in some parts of 
Maine, and in eastern Massachusetts, where there are only scattered hills 
with the valleys not much below the general level of the country, these 
ridges, of smaller size than in the great valleys, are found extending usu- 
ally north and south, without special regard to the present water-courses. 
In the valleys of our two largest rivers, the Connecticut and Merrimack, 
they extend long distances, but had heretofore escaped notice, owing to 
the large amount of levelly stratified alluvium, forming the conspicuous 
terraces and plains by which the underlying kames are often nearly 
concealed. Before this later alluvium was deposited, a kame had been 
formed in the Connecticut valley, which extended for many miles in a 
single continuous ridge, from one hundred to two hundred and fifty feet 
high, with steep sides; and in the Merrimack valley a continuous series 
of kames had been formed, consisting sometimes of a single ridge, and 
again of several parallel to each other. Another interesting series of 
kames extends from Saco river to Six-mile pond, and from Ossipee lake 
south-easterly along Pine river, and by Pine River and Balch ponds into 
Maine. The first description of any of these ridges in America appears 
