The Iowa plain dealer. [volume] (New Oregon, Howard County, Iowa) 1867-1895, 1889-11-21
SPAN LEVEL.

OF the croSS-piece d screw Q common
Is cent spirit level g, SO that when
stands on q level floor the air
bubble shall show level, and its middle
be tho middle Of d e. Change the tri.
angle end for end on the door
to be sure your spirit level is Oh.
actly parallel with the bottom Of b G.
Then II you want to graduate 1t raise
L-inch at time, leaving resting
on the floor, and mark the brass OF tho
spirit level for each quarter and half
inch up to two or three inches. Then
raise in the same way and graduate
the other side. Before the groove is
cut in tho bottom of the ditch this span
level may be applied all along, and
show the exact fall per rod. Then the
groove cutter can take out humps, and
tho level test its work. b is half q
rod long, and SO A-inch fall for its
length makes 1s-inch fall per rod, and 20
on. Never be content unless your level
shows some fall towards your outlet.
How TO LAY THE TILES. groove
should be cut SO that the tiles will at
without rolling, and shall touch bottom
all the way. Different sized scoops
should be used for different sized tiles.
Lay the tiles from the outlet up stream,
look through each tile to sec that it 10
clear Of distractions, and lay it so that
1t will not rock or wabble, |. O., curved
up, and not down In the middle, II curved
at all. Chuck it up tight against the
preceding tile, and then step forward
upon 1t and lay the next. prefer to
stand in the ditch, lay each tile by hand,
and stand on 1t to press it firmly to its
place. Assert the tiles in scattering
them along the ditch 50 that the harder
burned (smaller) ones shall come to-
Rether, and not be mixed in among the
softer-burned ones. But lay none that
are not hard burned enough to give .
clear, metallic ring when struck with .
hammer, and lay no cracked or broken
ones.
How TO COVER THE TLEs.-First,
stand in the ditch when the tiles are
laid, and with the ditching-spade shovel
In the fine clay (the subsoil last dug
out), and see that 1t rattles or fills clear
down on both sides Of the tiles. Tramp
very thoroughly with the feet as you
fill, until yal have filled in some eight
inches deep. The rest may be plowed
in by running q very long evener and
long inside lines, and having one horsc
on each side of the ditch. II possible,
the field drained In the fall should havs
been tiled in hoed crops all summer
The soil and subsoil are more moiss
early in the fall, and dig far more easily
than when in turf, or even in wheat OF
oats. Still further, the filing by team
is far easier, and the blowing Of the
field for the next crop will efface al!
| signs of the ditch.
The more uniform the fall the better.
II you know for example that your whole
fall is only one-half inch per rod, you
must keep your grade down to about
that rate, not varying, or yoa will have
trouble. Beginning at the lower end
the tendency of new hand. is to ''lose
grade," that is, work towards the sur.
face. The span level will help prevent
this. Instead Of the spirit level & Q
plumb bob may be hung by line from
it (see fgure), so that when b is leve!
the line shall come opposite the middle
of e. It's scale may be graduated and
marked as in the case OF the spirit
level.
SIZES OF TILES AND DISTANCES APART
This answers Q question not asked
but important. In very compact clay
subsoil, like that Of my Ohio farm
thorough drainage requires laterals from
thirty-thrce to ffty feet apart, to drail
the soil rapidly and thoroughly enough
to prevent damage to crops after yer.
heavy rains. This porous soil of low,
will ''draw'' one hundred feet or NOR
each side of q main laid in ''draw'' O
slough" and main drains through de
pressions, branching up minor depres
sions, will usually be enough. With fai
fall, tile will drain an area equal I.
one-half its diameter lin inches) squared
that is, q two-inch tile should carry tn
water from one acre 1.-TWO divided by tw'
and squared), four-inch tile four acres
. a five-inch tile about six acres and . six
: inch tile about nine acres; the less tn
grade the wider the suction range,
and the longer the drain the larger TIL
tiles required. A drain may begin st It
lower end with four-inch tiles, and d
mtntsh to thrss and then 70 twc howard
Ito upper snA.