1058 
Journal of Agricultural Research 
Vol. V ( No. 23 
ments except those upon the effect of contraction (p. 1091) the bottom 
of the weir box was approximately 4^ feet below the crests of the notches, 
and the sides of the weir box were 3 to 4X feet from the ends of the crests, 
depending upon the size of the notches. In all the experiments the floor 
of the spill box was approximately 4.5 feet below tne vertex, or crest, 
of the notch. 
Thirty or forty tests were made upon each notch, the experimental 
variable being the head. Intervals of head of 0.05 foot were used, and 
duplicate tests were run for each 0.1 foot of head. If the data from the 
duplicate tests did not agree within one-half of 1 per cent, the tests were 
