The San Francisco call., 1910-02-20

IlOn work, IL has been found that the
crushed stone produced by the granite
tailings left by the dredgers is far
superior to the ordinary quarried rock.
AT the present time there are three
rock crushing plants of from 1000 to
5000 tons capacity. devoted entirely 70
dredge tailings Two of these are
owned by the Natomas Consolidated
and one by the Valley Contracting Com
pany. Each plant requires the serv-
ices of over 35 men in it's operation.
and the output of the mills is being
used in all parts of the state. Pro
vision for the economical handling of
the cobbIestones. both before and after
crushing, are prevailing features in
al-the plants.
Every modern device known to sci
ence has been atilized to produce the
economy in operation necessary to
make the product available for exten-
sive road making. The plants are
equipped with several pairs of huge
jams and rolls. which crush the rock
TO any degree of fneness. One set
tuTHS OUT pioCSS TWO or JnEeS lDCQeS III
diameter; others crush into smaller
parts. while the lost rollers grind the
stone almost to dust. The material is
loaded on bumpers by means of huge
steam shovel and conveyed to the
erusher by donkey engines. Upon its
arrival at the mill it is sifted and
ground according to the size desired
by being run through great revolving
drums After being crushed the ma
terial is again screened and almost per
feet grinding secured. From the mill
the crushed rock is loaded upon ears
or dumped into the yard. which is
equipped with automatic loading de-
vices.
Although the manufacture of crushed
rock from Jredge tai1ings has only ex-
tended over a period Of one or two
years, the extreme hardness and supe-
rior quality of the stone readily Great
ed a steady market for this product
Some of the largest contracts for
crushed rock in northern California
have gone to one or the other of these
two companies. and the ground tailinss
are fast supplantinS other forms Of
macadam throughout the entire state
Over 80 miles Of macadamized road5cd
have been built with this material in
Sacramento county alone. AMI wherever
the slogan Of good roads is being heard
and answered by the counties from the
northern line of the state to the Te-
hachapi, the crushed cobbIestones have
set the standard for quality. and have
become almost the universal material
for road building. The finest example
of roadbed in this country extends frota
Sacramento to Folsom, and was coa-
structed of material furnished by tie
Natomas dredger. As sublayey for
asphalt pavements the finer grades IT
crushed stone are being used BY con-
tractors in Fresno. Modesto, Hanford.
Stockton and other cities with great
success.
The by-product of the dredgers was
used in the construction of some of the
Alameda bulkheads. The hard, strong
quality of the stone early appealed to
the discriminating eye of large contTac-
tors engaged in the erection of con
crete structures. and numerous build
ings throughout the Sacramento val
ley have been built from the product
of their plants. The new Sacramento
hotel in the capital city was built OF
Natomas crushed stone. as well as the
huge ice plant at Rosevipe.
The Southern Pacific IS an extensive
user of this variety of crushed rock.
a large quantity of it having gone into
the construction of the new line from
Roseville to Colfax. 1t is also being
largely used TO ballast the new Klam-
ath cutoff The Northern Electric rail-
way company also uses it extensively
in ballasting its roadbed. Crushed cob
bIestones have also largely entered into
the construction of some of the best
culverts and bridges built in northern
California during the last few years.
the extreme hardness and durability of
the stone being especially suitable for
use in these structures. Notwithstand-
ing the fact that the dredging com
panies have been in the rock crushing
field but a short time. the excellence
of their product and the cheapness~ at
which it is sold have enabled the product
of their mills to create steadily grow
ing market throughout a major nart -
California. and, like wave on til
ocean. its success is spreading into
wider and wider circles.
A notable thing in regard to the
dredging industry is that it depends
entirely on worthless or abandoned
land to make it's start profitable. The
farming land or acreage that has been
rejected on account of it's poverty and
uselessness for agricultural purposes is
carefully tested and if accepted for
dredging is soon purchased from the
surprised owner, who has perhaps spent
the best years of his life vainly trying
TO live along in a desperate. half
starved manner on the impoverished
scrabble land. half covered by cobbIe-
stones, over which squirrels, rattle
snakes and jackrabbits have absolute
dominion.