Smithsonian Report, 1944—Howard 
PLATE 4 
1. ENGINEER USING DYNAMOMETER FOR MEASURING MODEL RESISTANCE. 
2. CAVITATING MODEL PROPELLER UNDER TEST IN 12-INCH WATER TUNNEL. 
Picture made with 1/30000th-second flash. 
Note heavy tip vortices, considerable laminar cavitation near 
tips, and the start of burbling cavitation of the blade face near the hub. This is a right-hand propeller 
and the water is flowing from left to right. 
