Smithsonian Report, 1916. — Harts. 



Plate 6. 



Rock Excavation on the Tennessee River. Specially Designed Drill Raft 

 Boring Preparatory to Blasting. 



2. Crane Boat on Big Bend Shoal, Tennessee River. The Grapple Bucket 

 Handles the Loosened Rock, Previously Blasted, in One Movement from 

 Channel to Training Wall. 



