298 BOARD OF AGRIOULTUEE. [J.-m. 



in the Connecticut valley the soils are mainly composed of 

 detritus worn from the Triassic red sandstones of that region, 

 and have the characteristic color proper to the beds from 

 which the detritus has been taken. In the basin of the Nar- 

 ragansett coal field the bowlder clay has also the aspect deter- 

 mined by the general nature of the underlying carboniferous 

 strata, and partakes of the dark color common to those beds. 

 In regions where the bed rocks are silicious, the till is gen- 

 erally quartzose and infertile ; where the bed rocks are of a 

 limy nature, the materials of the soil are more fertile than 

 elsewhere. 



A yet further division in the character of the soils depends 

 upon the peculiarities attending the action of the glacial 

 envelope. When an ice sheet such as the last glacial period 

 brought upon the surface of New England is in the full- 

 ness of its activity, it is constantly removing material from 

 the surface over which it passes. This material is in part 

 commingled with the ice, probably to the depth of some 

 hundreds of feet above the bed rock, and is there borne on to 

 the southward with the flow of the glacial stream. A small 

 part held between the bed rocks and the ice is subject to 

 constant and rapid mechanical abrasion, and is thus ground 

 to powder. While this work of rending and pulverizhig the 

 rock is going on, the line material as well as a portion of the 

 pebbles is swept forward l)y the streams of water which from 

 time to time flow between the ice sheet and the subjacent 

 earth. In general these streams appear to have had no 

 great de})th, but to have been very extended in their action, 

 occasionally sweeping away the quantity of the rock waste, 

 and then ceasing for a long time to flow, permitting the 

 debris to accumulate to a considerable depth. At other 

 points beneath the ice the molten water was organized into 

 distinct streams, which appear to have flowed in caverns 

 excavated in the ice, moving forward towards the margins of 

 the glacier in a furious and tumultuous manner, as we can 

 imagine would be the case with water weighed upon by a 

 thick coating of ice, and thus pushed forward to its point of 

 escape. These streams pour out a vast amount of finely 

 divided rock to the open sea, or to the open air on the mar- 

 gin of the continental glacier. Escaping from beneath the 



