The Coalville times. [volume] (Coalville, Utah) 1894-1923, 1912-03-08

deep on the land
s. Ftyecighths miners inch ,
acre for $50 days equals 372 q
deep on the land
o. One.half miners inch per &c
for 100 days equals igS feet deep !
tho land.
10 One-half miners inch per &c
for l5O days equals 29S feet deep I
the land.
Weirs and Weir measurements.
Tho most accurate practical A.
economical method OF water NOS
uremcnt that has been devised 4
the measurement OF comparatifc
small heads OF water IL the ~
measurement. The weir Cunsistsf Z
scntially Of a thin notch Of specii
shape. which the water Is caused
flow over The amount Of flow 3
ponds upon the depth Of water a.
ng over the crest, as the huttotu
the notch Is called. The weir D.
been used for the measurement
water for hundreds of years and y
method Of Its installation and y
discharge ~ water can be mcasuri
over II with an error OF less than %
per cent. u care is used.
There are several forms NJ ives,
the name OF each design
Ing the shape Of the notch. Clp,'
lctu. an Italian engineer. eydlvt
and perfected the weir which lies
hls name. many years ago. this y
ing the weir that il now most CERT
ally used In the west
Weir Box.-ln order TO mainpn
the weir In proper and constnt
position and TO prevent leakFe
around and under II. and In orr
that all water that Is to be measusd
shou'd be conducted over Il. n IL
usually necessary TO construct sne
sort OF box or frame to hold No
weir In place. A common form or
type OF this box which II rom.
mcndcd for a one foot Clppofttl
weir IL nine feet long. two and q All
feet deep and three feet wide irdde
measurement. and with one bot
weir will measure with accpncy
amounts ranging from ten TO iity
Idaho miners inches.
Where a weir box Is built. n lshec
essary that II be made Of SUM dent
size and depth In comparison 10 The
size OF the weir notch TO clintfats
all excess velocity Of approach u
the box Is built too narrow OF toe
shallow It will add to the VELOCITY 81
TO such an extent that cor
rect measurement can not bo Sc
cured. II Is but n mere mater o'
convenience. however. to have boz
OF the exact length prescribed. for
that part of the box above the veii
may be omitted II n settling basin or
pool OF the same size Is CONSTRUCTED
in the ditch above the weir The
weir boxes and pools which shoult
be constructed for weirs OF hrgci
sizes should be In the same Inopof
ton with respect to the size 81 thu
weir as for the one foot. The sin
Of weir box that Ii required In ordg
to eliminate velocity OF approaerN
been found. by experiment. TO b n
proNimately seven times the eros
section OF the weir notch
Dlscharge.-The discharge Of velrs
has been accurately calculated by
various engineers who have carried
on hundreds OF experiments. cover
ing years OF time. and II is tounl
that under like conditions the sam,
depth always produces the same dc
charge over the same size Of a we'll
The conditions given for the COT.
structlon and installation OF veins
must be rigldly adhered TO. however.
II accurate measurement is 10 Va
made The formula which has ben
evolved and which gives the ds.
charge OF accurately CONSTRUCTED
Cippolctti welrs is
Q equals 3.3G7 l. II 80.
Where Q equals the number Of en-.
bic feet per second, l. equals tho
length OF crest IN feet and II EQUALS
the depth OF water on the crest IN
feet, provided the same Is measured
from a point level with the oreE and
up stream from II at a distance elual
to the length Of the crest
!. The weir box should be set vita
It's floor even with the bottom Of tho
ditch and should be level In all tlrec.
lions. The weir itself should be ex.
nctly level and perpendicular,
2, The channel leading TO the weir
should be OF uniform cross section, or
what Is still better. should gradually
enlarge as the weir In approached.
The axis OF the stream should pass
through the weir and perpendicular
10 IL; or. In other words, the weir
should be located at right angles 10
The middle OF the stream, The ad'
stream shoald be free from
Internal cross currents or oddie, as
Ihese have an influence upon the dis
charge
3. The water should be brought as
nearly as possible 10 n state OF rest
before II enters the weir. An excess
velocity Of approach due 10 the ye'
ocity Of the advancing current will az
Icct hncrease) the discharge more
han almost any other one thing.
This velocity can be reduced by Wild
'ning and deepening the box or pool
above the weir. II is calculated that
geirs three feet long with depth OF
water OF twelve inches. should not
have n greater velocity OF approach
han six Inches per second, which
mount may be allowed 10 Increase
'ery slightly where greater depths
over wider weirs are used. ny con
'tructing the box or pool above the
weir with cross section al least
'even times that OF the weir notch, a
low velocity OF approach
s usually secured.
ITO be Continued
One Way Of pavInu a Debt.