251
OF ENGINEEBING FOEMULÆ.
Pkessube of Water in Motion
Against a Plane Surface at Kight Angles to the Direction of
Motion.
Velocity of Water. Pressure lbs. per sq. foot. ] Velocity of । Water. Pressure Iba. per sq. foot. Velocity of Water. Pressure lbs. yer 8q. foot.
Miles .per hoar. Feet per second. । Miles i Per ihour. Feet per second. Miles per hour. Feet per second.
1 1M67 2-1 1 11 16-133 254-1 21 30-8 926‘1
2 2-933 8-4 12 17-6 302’4 22 32’266 1016
3 4-4 18-9 13 19-067 354’9 23 33'733 1111
4 5-867 33-6 1 14 20•533 411'6 24 35-2 1210
5 7'333 52-5 15 22 472-5 25 36'667 1312
6 8'8 75-6 16 23-467 537-6 26 38’113 1420
7 10-267 102’9 17 24•933 606-9 27 28 39-6 1531
8 11-733 134-4 18 26-4 680-4 41-067 1646
9 13-2 170-1 19 27•867 758-1 29 42-553 1766
10 14'667 210 20 29 • 333 840 30 44 189Ü
For Table of Pressures at Different Velocities in Knots per
hour, see Resistance to Vessels.
Gauging Water.
H = Height of surface of water above sill in feet.
h =■ Ditto if measured in inches.
V — Velocity of water approaching the sill in
feet per second.
C = Cubic feet discharged over each foot width
of the sill per minute.
C = 214 VH31 if the stream above the sill is
= 5’15 I n°t
= 214 VH3 + '035 V2 H2 if in motion.
In gauging, the waste-board must have a thin
edge. The height must be measured from the
top of the sill, or waste-board, to the level of
the surface where it is not affected by the overfall.
The wa^te-board must have a free overfall.