102 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



These figures probably re])resent more than double the average dis- 

 charge if taken for the whole year. The discharge in summer is 

 estimated about 13,000 cubic feet. 



None of the streams connected with the drainage of the basin have 

 the drainage area of the Cumberland. 



In the central division the Duck River forms the channel of out- 

 let. This stream flows almost through the centre of its drainage area 

 sending out small creeks to both sides. This area is limited to the 

 south by the Elk Ridge, and on the north by a long narrow spur of 

 Nashville i-ocks. The Duck River is a tributaiy of the Tennessee. 

 As may be indicated by its drainage area it is less than half the size 

 of the Cumberland, it is not navigable, and no reliable data have ever 

 been kept regarding it. 



The Third or Southern drainage. division is that of the Elk Rivei\ 

 It is divided from the Duck River area by the Elk Ridge, and is 

 limited on the south by the escarpment forming the rim of the Basin 

 along which it skirts ver}-^ closely. The Elk is a tributary of the Ten- 

 nessee River. 



In Tennessee these streams drain the Highland Rim, and in Ken- 

 tucky the chief drainage channel is the Ohio River with its tribu- 

 tai'ies. The whole of the State of Kentucky, with the exception of 

 probably about 1,000 miles lies within the area belonging to the Ohio 

 division of the Mississippi drainage basin which is estimated to be 

 lowered by one foot in 5,000 yards. 



. The conclusions naturally arrived at from a consideration of all the 

 facts connected with the geological structure of the country under 

 consideration are these. That the territory now occupied by the sub- 

 carboniferous beds was elevated at the close of the sub-carboniferous 

 period ; that the greater part of it was above the level of the marshes 

 in which the coal beds were formed ; that the Central Basin of Ten- 

 nessee is a basin of erosion, and that the amount of denudation neces- 

 sary to form the Highland Rim in its broadest extent and the Cen- 

 tral Basin was the work of the present system of drainage. 



The rivers and streams of Kentucky have a generally westerly and 

 easterly course and all have cut for themselves deep channels. Some 



