204 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



Measurements at Burlington, loiva {JfO miles above Keokrik). 



1 In 1866 there was no standard gauge at Burlington and this gauge reading is ap- 

 proximate only as compared with the present gauge, which was established in 1872. 



The observations listed above, purposely selected as showing the 

 least discharge of record, have led the engineers of the development 

 to establish in their calculations a minimum discharge of 20,000 

 second feet. Otlier observations of minimum discharge, made in 

 1906 under the direction of Mr. Cooper by a current meter, may 

 serve to show the safe margin of surplus power often available over 

 the amount calculated on the basis of the above minimum. 



Measurements at Nashville, lorva (6 miles above Keokuk). 



The waters at Keokuk can not accurately be called turbulent. 

 They are not hurled over hidden bowlders and irregular rock with 

 the speed of a Niagara. The river has much less velocity and pre- 

 sents rather the smooth appearance of water running down an in- 



