The record-union., 1895-02-05

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From the foregoing, it is evident that
J the area required for the successful re-
| straint of the probably workable gravel
| is large.
| Closely allied to the subject OF area re-
| quired, Is the composition OF the gravel
as to relative size, in order TO determine
! its capability Of transportation and set
! tlemeut.
! 1t is a subject which has received but
! little attention, is difficult to state, vary
| ing as 1t does with different mines and
| in tho banks themselves.
| William Ham Hall, in his reports, esti-
mate that probably IS per ceut. OF the
gravel could be restrained behind dams
| in the mountains-Or, say, coarse sand
and gravel-leaying - per cent. for clay,
! soil, etc.
| From experiments made by the writer,
! the composition of what might be called
average gravel may be stated as 20 per
| cent. cobo!e and gravel, 70 per cent. sand,
| and 10 per cent, soil and clay.
! The soil and clay forming the suspen-
! satory matter is carried by low veocites,
/ and would be utilized Tor reclamation
! purposes.
The sand and gravel deposits on a grade
| OF about fifteen feet 10 the mile must Of
necessity find lodgment near the rivers,
! or the base of the mountains where the
rivers enter the valley.
PAST PLANS FOR IMPoUNDING DEBRIS.
During the past years many methods
have been proposed for the impouudiUU
OF the debris.
With the miners, the building of re-
straiuing dams at suitable places within
the main water courses has been the
favored method.
These dams will prove effective in i'm
pounding say % per cent. OF the material
washed.
What effect the floods laden with fine
sand would have in eroding them is as
yet undetermined. Undoubtedly they
VIII have 10 DO built OF masonry. laid
win cement. when the winter foods are
10 pass over them.
1t viii be necessary to build them
great h!ght to gain capacity. To illus
trate: 10 construct dam IN the ordinary
portions OF the Guba, where the Cauv0n
is say 800 feet wide at sixty feet above its
I bed, the estimated wash OF gravel for 1880
would make 4 solid bed $50 feet wide.
four miles long and sixty feet high, al
| lowing 10 per cent. OF the material being
impounded. ana, taken in conjunction
with the grades of twenty-five to 100 feet
per mile, Will give an idea of the hight
equlTeu.
By building a dam nearer the base of
the mountains, where the river is wide
the debris now in the river would I'LL the
dam before the taiIings of the mines
could reach them.
1t is therefore obvious that the General
Government should restrain the debris
now deposited so that the miners could
build dams and be able to get the advau-
tage OF them as well as protecting the
streams
In view of the fact that the Debris
| Commission has recommended that the
miners build their own dams, il seems
pertinent to inquire if there is not a
! cEeaper method OF gaining the same OBJ
ject.
Many have proposed the carrying of
the debris IL canals or fumes from the
mines to the swamDs OF the Sacramento.
But this is attended with many difficult
ties, which, 10 the writer, seem insur-
mouEtaole.
First-Ihe Feather would have to be
crossed with bridge
Second-The necessary grade to carry
the -tailings even across tho plains is
wanting.
The 1uba River, for instance, has a
grade from the base of the mountains to