The La Jara chronicle., 1911-05-26
FARM ENGINEERING.
Small Concrete Weirs
for the Farm.


constructed of wood last from
three 10 six years, with an an
nual maintenance OF more or less
expense. a weir that will last
indefinitely can be constructed of
concrete, at moderate first cost,
and no maintenance charge.
First, determine the position of
your weir and Tie maximum
amount Of water you expect to
discharg" through it. This hav-
ing been done, eXcavatc the ditch
TO level surface, to a depth of
four or five inches below the orig
inal bottom. The length of the
base viii be, in our case, say,
eight feet. At each end of the
foundation pit make small
trench, reaching across the bot
tom from side to side. The width
OF the foundation will depend up
on the size of the weir needed.
Assuming a two-foot weir, we
would make the base five and
onehalf feet. Now mix your con-
crete, one part Portland cement,
three parts sand, and six parts
'.avel or broken stone, and place
this in the pit as provided. The
small trenches at the ends will
serve as curtain wall and pre-
vent the water from flowing be-
meath the base. While the con-
crete is being placed there should
be set scantling two inches
square and full length of base.
directly underneath the center of
the side walls of the Weir. Now,
place four one-half-inch iron rods
in the base, to extend vertically
on the outside of the scantling
and to extend some six or eight
inches above the finished surface
of tine base. 1t is advisable to
bend the ends of these rods at
right angles, the lower end ex-
tending out into the base at right
angles to the axis of the ditch.
These rods should be equally
spaced, with first and last one a
foot from each end of the wall.
The two scantlings will be par
allel with each other, and after
the concrete has all been placed
and tamped into position, and
floated with stralghtedge,
these strips should be flush with
the surface. There should be a
side margin of concrete on the out
side of them at least four inches
wide. The finished surface should
he approximately level. No forms
will be necessary for the construc-
tion of the base of the weir.
The forms for the sides of the
weir are of collapsable nature
and can be used for different
widths and for an indefinite num-
her of structures.
Twelve pieces of 2xs, nine
feet long, constitute the four
side pieces, two side pieces being
required to form each side wall.
At the ends of the outside pieces
are two long eye bolts reaching
to the opposite side. These bolts
are threaded for some distance,
permitting of varying widths. To
form the ends of the wall is
placed vertically a board, five
inches wide, two feet long, held
in place by cleats. Two pieces
of 2x4 at each end, cut the proper
length, serve as struts or spread
crs. After the end boards form
ing the ends of the walls, and the
struts are in place, the turn nuts
on the eye bolts are frightened,
thus causing the whole form to
be rigidly connected and properly
spaced. The eye bolts are hinged
at the diagonal corners and the
end pieces are slotted to permit
of easy assembling. At about
three feet from the lower end of
the wall must be placed the weir
board To provide a recess for
it in the concrete side wall a 212
x2-inch cleat is nailed vertically
on the inside of the inside forms.
A slight draft should be given to
the clcat so that there will be
less danger of crumbling the cor