Smithsonian Report, 1916. — Harts. 



Plate 5. 



1. The Wickets of a Movable Dam on the Ohio River, Showing Signs and 



Method of Tripping. 



<*'jrV^j!t'!!^''^:^!:^^^0£^--^'^^i.^ ■ 



2. A New Concrete Lock on the Lower Cumberland River. The Gates are 



NOT YET IN Place. 



