Srom the melting of the Quaternary Glacier. 89 
height and violence; and the deposits now at or about their 
mouths contain, at various levels, such evidences of their per- 
general direction of the valley. Consequently, eastern and 
western tributaries and Connecticut river ice-floes may have 
carried in stones from the same northern and north-northeast- 
ern source. 
Moreover, since the till consists ordinarily: of (1) stones, 
large and small, (2) earth or finely pulverized rock, and 
usually (8) of more or less clay, it supplied (a) clay for clay- 
beds, (6) sand for sand-beds, and (c) gravel and stones for 
coarser deposits. And, as the rising waters reached successively 
higher and higher till-covered levels, submerging ledges and 
the lower hills, and rising against the slopes of the higher, so 
clay-beds should have been formed from the clay of the till at 
various levels in the terrace formations, like the sand-beds an 
gravel beds;* but the extent of them should be relatively 
small, or in proportion roughly to the clay in the till. The 
material of clay-beds may have come also from other sources ; 
*The heights of many of the clay beds are mentioned’ beyond. 
