--------------+----------+------------+-----------+------------
Alexander | 59,856 | 160 | 120.0 | 0.321
Cotterill | 57,013 | 152.4 | 114.3 | 0.306
Molesworth | 59,201 | 158.2 | 118.7 | 0.317
Thomson | 57,166 | 152.8 | 114.6 | 0.306
--------------+----------+------------+-----------+------------


Cotterill's formula for the discharge in cubic feet per minute
is
_______
16 x C x B \/ 2g H^3

when B = breadth of notch in feet and H = height of water in
feet and can be applied to any proportion of notch. When B =
2H, that is, a 90 notch, C = .595 and the formula becomes
____
152.4 \/ H^5,

and when B = 4H, that is, a notch containing an angle of 126
51' 36", C = .62 and the formula is then written
____
318 \/ H^5.


The measurements of the depth of the water above the notch
should be taken by a hook-gauge, as when a rule or gauge-slate
is used the velocity of the water causes the latter to rise as
it comes in contact with the edge of the measuring instrument
and an accurate reading is not easily obtainable, and, further,