Great Falls tribune. [volume] (Great Falls, Mont.) 1885-1890, 1886-09-18

LII IN "ttSA tAS oAISi
small openings are made with a shove.
at short distances, and the ditch damned
if necessary until 4 sufficient quantity o.
water has been turned upon thc land. The
process is watched and if any part of the
field is not receiving its supply a small
trench is made directly 70 il. The open
ings thus made are then closed up and the
water turned to other parts Of the field.
The two irrigations thus usually given for
wheat neyer more ta4i tarea} ;.te equal
to Il rainfall Of thrsa to i've inclc5, during
the time needed.
The tol.l cost Of irrigation is 50 to s22.50
per acre, and one man Can irrigate eighty
acres.
Among the advantages claimed for irri-
CATION are immunity from drouth or from
excessive moisture and flood. The ability
to control the growth Of Z plant as to seq
son, and to cultivate a wider range of
plants: also to supply. certain elements to
the soil Is p~hosphates, etc. ~abuniantiy car
ried by the water Of the noantain streams,
or to wash them out Wi.ara il excess. The
silt carried, grandally ills the pores of the
soil and makes it more retentiye and fer
tile.
The duty Of water, il is thought, can be
increased to 100 to 1870 acres per cubic foot
per second, as the present u.s. of the water
is excessive. The present standard of old
irrigating bitches is one Cubic foot per
second, during the irrigating season Of 100
day, for about fifty acres. N some cases
this has been raised to about SIXTY &sres,
and is equivalent to an annual rainfall %
about twelve feet.
In reference to construction of canals,
the slopes are determined By the amount
Of water 70 be carried, the nature Of the
soil as to friability. as To whether the wa
ter IS silt-bearing or not, etc.
As to cross-section. it IS not usually nee
essars to build banks on both sides. The
bottom width is usually two and 4 half
times the depth, and often q subgrade Of
one 10 two feet is made 1T the enter with
4 wide bernie between it and the toe Of the
embanlanent. The inner Scopes OF banks
in loose soils are made two o. three to one:
IN firm soils one and = half CT two to one:
ana in rock from one-fourth to
ono, ID 70 one to one. Head
autas are Very simple made Of wool,
witll iron screws for raising and
lowering, but tIley are net often as sub
s~tantalty .aade as they ought to be, cons;d-
er;ne their importance, and are frequently
DC t@cye5 by floods,
IL sasae localities, for Typographical o.
economic reasons, sudden drops il The line
ot Ut IL are desirable. When not too great,
Il SIN. te ta3, set below the lower grade
line. receives the water as it falls, and it is
thea discharged a]gaia-ta boom Of solid
tir4haIs laa ehro#n bssG IN > paa+-pcA
wn"ace Il a7a@ne5 ovt, etnaiad flor.
It'll aialcs.l1 u ala .,l where u Iess
grade tEs;a oa2 inch pear 100 feet il need
/. aaf a@eapt in loose sandy soil @'
ia in i II inches ss9a 3e USED. .
streams Ie.v.lva s1a4,.s-@.4. nth De-.
from eo3d wa.hing= , - inches per 100
faet ii i5st about sufficient u remove the
sediment a5la prevent itS accumulation in
thu bends 81 the diJohas.
Slopes in cuttings = P11i 7 be les tA3n
n to one. y tiatter they ara more expos
ell to wash from s-,dlea rains, aHi ara
finally reduced to Old ~ sta,ner. II IA
open cutting around L ma13tain sl"p, the
ditch bottom should N slopcd downward
towards the hilI.4to,7 Of foot, thusthfow-
ing the wearing force Of the curr"r; n"ar
The moHnt.iin side ana away from the
bank. and diminishing the danger OF cut
ting.
It is hoped t'aat tie readers Of your val
table paper Will clean from the above the
idea which it is desired to impress them,-
the ereat value of irrigation. It is be-
lieyed that no city has better facilities for
an abundant supply Of water than Great
Falls. Let it, Therefore establish a system
Of irrigation, and it will not only have
beautiful lawns and shade trees, but immi-
grafton viii be greatly increased, and its
already popular ANN will beconae more
popular. and its perfect success ens@"nd.
=.
New England