102 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



These figures probably represent moi-e 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. ThLs stream flows almost throucjli 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 rocks. The Duck River is a tributai-y of the Tennessee. 

 As may be indicated l>y its drainage ai'ea 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 Southein drainage division is that of the Elk River. 

 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 very 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- 

 taries. 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 ]\Iississip])i drainage basin which is estimated to be 

 lowered by one foot in 5,000 yards. 



The conclusions n;iturally arrived at from a consideration of all the 

 facts connected with the geological structure of the country under 

 consideration are these. That the territoi-y now occupied by the sub- 

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

 period ; that the gieater jiart of it was above the level of the marshes 

 in which the coal leds 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 bave cut for themselves deep channels. Some 



