_Coefficients of Discharge of Standard Weir._
+----------------+--------------+--------+
| Head h metres. | Head h feet. | m |
+----------------+--------------+--------+
| 0.05 | .164 | 0.4485 |
| 0.10 | .328 | 0.4336 |
| 0.15 | .492 | 0.4284 |
| 0.20 | .656 | 0.4262 |
| 0.25 | .820 | 0.4259 |
| 0.30 | .984 | 0.4266 |
| 0.35 | 1.148 | 0.4275 |
| 0.40 | 1.312 | 0.4286 |
| 0.45 | 1.476 | 0.4299 |
| 0.50 | 1.640 | 0.4313 |
| 0.55 | 1.804 | 0.4327 |
| 0.60 | 1.968 | 0.4341 |
+----------------+--------------+--------+
Bazin compares his results with those of Fteley and Stearns in 1877
and 1879, correcting for a different velocity of approach, and finds a
close agreement.
_Influence of Velocity of Approach._--To take account of the velocity
of approach u it is usual to replace h in the formula by h + au²/2g
where [alpha] is a coefficient not very well ascertained. Then
Q = [mu]l (h + [alpha]u²/2g) [root]{2g(h + [alpha]u²/2g)}
= [mu]lh [root](2gh)(1 + [alpha]u²/2gh)^(3/2). (2)