Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-11-11

from the needle and inserted willow toggles
sticks Is inches Icing. The workmen above
then drew back their needles and wire and
pulling taut on the latter with their feet each
side of the wire, the brush was of course
drawn together and thus packed to thick
ness of one foot They then stepped forward
two feet, sent down their wire threads again,
other toggles were inserted, and thus regular
stitches were made from side to side. In each
mattress are three or four or fve-according
to size--of these lines of stitching. The
diagonal lines represent the brush thickly
placed, sewed together with wire and wired
to the intervening longitudinal layers OF
| logs. the first and only visible one being in
dicatetl on the face of the dam by
the round marks at B. These layers
| of sewed and matted willows vary
| from five to eight in number as the
irregularity of the ground necessitates.
| The brush tops all descend to and are buried
| in the sand at G, but are closer together at
that point than is possible to indicate in the
diagram, which also makes the slope con-
siderably more abrupt than it is in fact.
The wave lines ID indicate the top dress
ing of sand and slickens, which begins some
| two or three feet below the lip of the dam
and extends to the river bed, thickening at
the junction of the dam and the plane of the
bed to make that union of exceedingly gentle
and easy slope. Extending from the lip OF
the dam downward and beneath the layer Of
earth is the layer of logs before mentioned,
and wired down to the brush in the most sub
stantial manner.
The dam does not join the high Ian OF
the N north a nor the levee on the south
at right angles, but the union i;
made by curved levees geo feet long
4 feet higher than the dam, some 100 feet
wide at the base, and with a slope of foul
and FIVE to one on the upper side. Where
these levees join the dam o massive square
crib is placed, made of logs bonded together
the crib being filled with brush and earth anC
the levee built over the crib. Into the side
of each crib the brush dam enters and is in
terwoven with and between its logs, and thus
the two are bonded together.
1t should here be noted that as the brnsl
IN the dam was placed in position it was fou
/ feet thick, and each layer. prior to being
sewed down with wire to the legs beneath
was pressed with great levers into thick
ness ranging from one to two feet.
IT WILL BE SEEN
| That such structure cannot wash away. Il
has little pressure to resist. The longer il
| remains the stronger it must get The watel
will seep through it, and possibly rise and
flow over it; but TO do so it must How owes
the whole length of the lip in thin sheet
two miles long. Meanwhile the heavy mat
ter brought down will settle in the basin OIL
reservoir thus formed, and which has now 9
width of from one and three-quarters to two
miles, and length of between six and eight
miles, and will store, it is estimated, with
ease, rs, O00, COO cubic yards of solidly packed
earthly matter The dam cost. in round num-
bers, 100000; but the foundation being all
laid, and the superstructure complete, add
tional hight can be given to it for one-tifth OF
its cost, sufficient to enable it to store
twice the quantity of matter named
1t is variously estimated, but by none
placed at less than three years, In which this
reservoir may fill with detritus. But the
creation of this reservoir will, it is held CHECK
the flow of water above it to such an extent
that the heavy material will be deposited
along the river far above the water-level line
of the reservoir itself. and thus the quantity
of debris to be checked by this dam is not t.
be measured by the simple capacity of the re
servoir ITSELF Nor is it to be assumed thai
the filling of this reservoir will be upon thu
plane of water level; on the contrary, i
will fill on the plane of the descent of thu
river bed, and thus the filling at the uppel
end will be
| FAR HIGHER
Than the crown of the dam below. This dia
gram may serve to make this clearer: