The Placer herald., 1856-12-20


ture of money. One of them was sunk by
the San Francisco and Stockton Mining Co.,
on Roach Hill, two miles east of Iowa Hill
This shaft is three feet wide by nine in length,
and one hundred and ninety seven feet in
depth; is curbed from top to bottom with
plank, having a partition of plank in the
middle, thus forming two shafts. The cost
of lumber alone was fifteen hundred dollars;
twelve horse power engine was used in its
construction, raising gravel and water. The
cost of the engine and boiler when delivered
on the ground, was three thousand dollars.
The average price of labor paid for construct
inc the shaft, five dollars daytime, eight
months-total cost, seventeen thousand dol
lars. The San Francisco and Stockton Co.,
found gravel rich with gold at the bottom OF
their shaft, and after having tunneled some
distance, and becoming satisfied that the
rich deposit was extensive, they contracted
with Edward p. Steen, of the city of San
Francisco, to run with his Tunnel Borer,'
tunnel, five hundred feet long and six feet
in diameter, to strike the bottom of the shaft
to drain the water from their mining ground
Tne amount of the contract is $3.50. If
the contract is completed before the 2Sth
Of January next, a bonus of -, 700 is to be
paid, thus making the expenses of the com
panv, on the completion of the tunnel,
$27, $50. | consider the Tunnel Borer" the
most useful of all inventions for the working
of the mines, and as it will be in operation
in few days at Roach HILL | think it not
inappropriate to describe it,
This machine, was invented, Except the
cutters) and built at San Francisco by Ewd.
p. Steen. 1t consists of two machines--one
for cutting the tunnel, which feeds itself in
as fast as it cuts-and the driving machine,
which is erected outside, and is stationary.
The cutting machine consists of strong
iron frame, mounted on Wheels which are
conical, and run on the sides of the bottom
of the tunnel. Boled to this frame is an en-
gine, twelve inches bore, by sixteen inches
stroke the piston of which is connected with
two bell cranks, hung by centers to wheel
or face plate, which is moved around from
a half to one inch at each stroke Of the pis-
ton, according to the hardness of the rock.
The cutters, -four in number) are round
plates of steel, ten inches in diameter, bv
ve-eighths of an inch thick, hung on small
shafts, which run in boxes attached to the
bell cranks at an angle of forty-ive degrees
to the face plate. When the piston moves
it gives a half circular motion to the bell
cranks and cutters, and when the latter are
in contact with the rocks, causes them to ro-
tate on their own axes, and thus cuts the
rock with the least wear or friction. The
tunnel it cuts is six feet in diameter.
The driving apparatus consists of steam
boiler, engine and pump for compressng air;
the compressed air is conducted any distance
through rubber hose, to the cutting machine,
and applied to the engine, in which it works
as steam The air is exhausted in the tun-
ne keeping it well ventilated.
This machine has cut tunnel in Telegraph
Hill, San Francisco, six feet in diameter, from
twelve to sixteen inches in an hour, and re-
quires about two and half cords of wood
per day of twenty-four hours. Eight men
can run the machine night and day-two
engineers and two working men at a time.
Eight cutters will cut one thousand feet
of tunnel in rock of ordinary hardness; the
machine will cut up and down grade, and
turn a curve of twenty feet radius.
The rock &C., is drawn out under the ma
chine, and run out the usual way.
1t is estimated that Placer county has
produced from its mines during the past year,
gold to the value of $6,OO0,OOO. The cost
of the different articles of merchandise con-
sumed in this county during the past year,
will amount to 100000
The population of this county is gradually
on the increase. The official returns of the
late election show the number of votes to be
H., Df al
past year. The estimated population Of the
county is-whites (male( 1880. Females,
1860. Negroes, (male and femae) 400
Cinnamon, $500. Indians, (male and female,)
1876. Total population, including all classes,
1S,425.
Upon entering on the duties of my office,
| was surprised to find we were without a
map of the county-neither field note Of
any kind. The Clerks Office is without a
county map. The official map of the State
of California, by an act of the Legislature
passed March 25th, 1853, | have no hesta-
ton in saying, is most lame and inefficient in
its delineations Of the topography Of this
county 1t will take several years to com
pile a correct map of this State, and the
Legislature should make liberal appropria-
tions for that purpose.
An act dividing the State into counties
passed April 25th, 1851; defines the lines Of
Placer county in this manner:
"Beganng at the Sacramento River at
the northwest corner Of Sacramento county,
and running thence up the middle of said
river to point ten miles below the junction
of Sacramento and Feather Rivers; thence in
northerly direction in straight line to a
point in the middle of Bear Creek, opposite
Camp Far West; thence up the middle of
said creek, to its source; thence due east to
the State line; thence southerly on the State
line, to the north-easterly corner of Ell Dorado
county; thence westerly, on the northerly line
of Ell Dorado county, to the junction Of the
north and south forks Of the American River: