Revolutions, per second 
o 18 
<1111 
VelOcitY*'*" "feet P er second. 
EXPLANATION 
Bureau of Standards ratings; 
* Meter on rod. 
° Meier on cable, 15 pound weight. 
Galexico,CaHfornia, ratings,on rod. 
Meter submerged about 1 toot. 
* Rod vertical. 
° Meter tipped upward about 5 degrees. 
Meter tipped downward about 5 degrees. 
Meter tipped upward about 15 degrees. 
Meter tipped downward about 15 degrees. 
Meter tipped upward about 30 degrees. 
® Meter tipped downward about 50 degrees. 
Dull pivot point, rod vertical. 
* Open ends of cups near 1 to l concrete slope. 
* Closed ends of cups near 1 to I concrete slope. 
Q Meter just clearing level concrete bottom. 
ttG. i.—Standard-rating curve on logarithmic scale, as developed by U. S. Bureau of Standards, for new cup meter, with points developed by rating the same meter at Calexico, Cal., under 
conditions similar to those under which it was originally rated and under other conditions not met in the usual rating. 
41217®—(To face page 78 ) 
