AN ENGINEERING TRIUMPH.
Another work that has been of great benefit to the towns along the
Comstock, and to all the mining and milling companies in and about the
towns, and along the cañons below, was the bringing of an ample supply
of pure water from the Sierra Nevada Mountains.
In the early days, when the first mining was done at Virginia City and
Gold Hill, natural springs furnished a supply of water for the use of
the few persons then living in the two camps. For a time after the
discovery of silver, these springs, and a few wells that were dug by the
settlers, sufficed for all uses, but as the towns grew in population, an
increased supply of water was demanded. A water company was formed and
the water flowing from several tunnels that had been run into the
mountains west of Virginia City for prospecting purposes, was collected
in large wooden tanks, and distributed about the two towns by means of
pipes. At length the tunnels from which this supply was obtained began
to run dry, and a water famine was threatened. It then became necessary
to set men to work at extending the tunnels further into the hills to
cut across new strata of rock. This increased the supply for a time,
but, at length, the whole top of the hill into which the tunnels
extended appeared to be completely drained.
Early in the spring, when the snow was melting, they afforded a
considerable supply; but in the summer, when water was most needed, the
tunnels furnished but feeble streams and these were much impregnated
with minerals, one of the least feared of which was arsenic. The ladies
rather liked arsenic, as it improved their complexion; made them fair
and rosy-cheeked—almost young again, some of them. The miners did not
object to arsenic; as, while it did not injure their complexion, it
strengthened their lungs—made them strong-winded, and able to scale
mountains. (Every man of them hungered to hunt the wild chamois.) But
there were other minerals held in solution in the water—those that
caused diarrhœa for instance—that were not so well thought of.
The nearer hills having thus been drained, tunnels were run into such of
those further away as were of sufficient altitude to permit of streams
from them being brought to the two towns. These tunnels were run for no
other purpose than to find water. A hill was examined with a view to its
water-producing capacity. It was found that those which rose up in a
single sharp or rounded peak were not rich in water. The best
water-producers were hills on the tops of which there were large areas
of flat ground. That portion of a range of mountains which contained on
the summit a large shallow basin surrounded by clusters of hills or
peaks was found to yield largely and for a long time, when tapped by a
tunnel run under the basin or sink at the depth of three or four hundred
feet.
Dams were constructed across the outlets of these basins to hold back
the water from the melting snow, in order that it might filter down
through the earth to the tunnels. At the mouths of the tunnels heavy
bulkheads of timbers and plank were constructed, to keep back and dam up
the water where it could be kept cool and pure. Where deep shafts stood
near the line of these tunnels, ditches were dug to them along the sides
of the hills, and the water formed by the melting of the snow in the
spring was let into them. All manner of devices, in short, were resorted
to for the purpose of keeping in and upon the hills all of the moisture
from snow or rains that fell upon them. Yet one after another these
hills failed. When once the tops had been thoroughly drained it appeared
to require all of the water that fell on them in any shape during winter
to reach down into and moisten them to the level of the tunnels.
Finally, there were in all many miles of these horizontal wells. All the
hills from which water could be brought, for miles away to the northward
and southward of Virginia and Gold Hill, were tapped, thousands on
thousands of dollars being expended in this work. When a reservoir of
water was first tapped in a new hill there would be poured out a great
flood for a few days; this would then fall to a moderate stream and so
remain for a month or two, when it would begin to dwindle away. The
water from the many tunnels was collected by means of small wooden
flumes or troughs, winding about the curves of the hills for miles, and
in summer, when most wanted, the sickly streams from the more distant
tunnels were lost by leakage and evaporation before having finished half
their course to the towns.
Virginia City and Gold Hill were frequently placed upon a short
allowance of water, and it was seen that a great water famine must soon
prevail in both towns, in case the tunnels that had been run into the
mountains were depended upon for a supply. The Virginia and Gold Hill
Water Company then determined to bring a supply of pure water from the
streams and lakes of the Sierra Nevada Mountains—from the regions of
eternal snow.
The distance from Virginia City to the first available streams in the
Sierras was about twenty-five miles; but between the Virginia range of
mountains and the Sierras, lay the deep depression known as Washoe
Valley,—in one part of which is situated Washoe Lake. The problem to be
solved in bringing water from the Sierras to Virginia City was how to
convey it across this deep valley.
Mr. H. Schussler, the engineer under whose supervision the Spring Valley
Water Works, of San Francisco, were constructed, was sent for, and
crossing the Sierras he made an examination of the route over which it
was proposed to bring the water. He acknowledged that the undertaking
was one of great difficulty. To convey the water across the deep
depression formed by Washoe Valley would demand the performing of a feat
in hydraulic engineering never before attempted in any part of the
world. This was to carry the water through an iron pipe under a
perpendicular pressure of 1,720 feet. This feat, however, Mr. Schussler
said could be performed, and he was ready to undertake it at once.
Surveys were made, in the spring of 1872, and orders given for the
manufacture of the pipe. To make the pipe was the work of nearly a year.
The manufacturers were furnished with a diagram of the line on which it
was to be laid and each section was made to fit a certain spot. When the
route lay round a point of rocks the pipe was made of the required
curve, and other curved sections were required when the line crossed
deep and narrow ravines.
The first section of pipe was laid, June 11th, 1873, and the last on the
25th, of July the same year. The whole length of the pipe is seven miles
and one hundred and thirty-four feet. Its interior diameter is twelve
inches, and it is capable of delivering 2,200,000 gallons of water per
twenty-four hours. It lies across Washoe Valley, in the form of an
inverted siphon. The end at which the water is received rests upon a
spur from the main Sierras, at an elevation of 1885 feet above Washoe
Valley. The outlet is on the crest of the Virginia range of mountains,
on the eastern slope of which are situated the towns of Virginia and
Gold Hill. The perpendicular elevation of the inlet above the outlet is
465 feet. Thus is brought to bear a great pressure which forces the
water rapidly through the pipe.
The water is brought to the inlet through a large wooden flume, and at
the outlet is delivered into a similar flume, twelve miles in length,
which conveys it to Virginia City. The pipe is of wrought iron, and is
fastened by three rows of ⅝ inch rivets. At the lowest point in the
ground crossed, the perpendicular pressure is 1,720 feet, equal to 800
pounds to the square inch. Here the iron is 5/16 of an inch in
thickness, but as the ground rises to the east and west, and the
pressure is reduced, the thickness of the iron decreases through ¼,
3/16, down to 1/16.
In its course, the pipe crosses thirteen deep gulches, making necessary
that number of undulations, as it is throughout its length laid at the
depth of 2½ feet below the surface of the earth. Besides these, there
are a great number of lateral curves round hills and points of rocks.
There was just one place and none other for each section of pipe as
received from the manufactory. At each point where there is a depression
in the pipe there is a blow-off cock, for the removal of any sediment
that may collect, and on the top of each ridge is an air-cock, for
blowing off the air when the water was first let in, and at other times
when the pipe is being filled. The pipe contains no less than 1,150,000
pounds of rolled iron; is held together by 1,000,000 rivets, and there
were used in securing the joints 52,000 pounds of lead, which was melted
and poured in from a portable furnace that moved along the line as the
work of laying the pipe progressed. Before being put down, each section
of pipe was boiled in a bath of asphaltum and coal-tar, at a temperature
of 380 degrees. At the first filling of the pipe a stream of water,
about the thickness of a common lead-pencil, escaped through the lead
packing of a joint, at a point where the pressure was greatest. This
struck against the face of a rock, and, rebounding, played upon the
upper side of the pipe. The water brought with it from the rock a small
quantity of sand or grit, perhaps, but at all events it soon bored a
hole through the top of the pipe, and from this hole, which shortly
became two or three inches in diameter, a jet of water ascended to the
height of two hundred feet or more, spreading out in the shape of a fan
toward the top.
When this break occurred, a signal smoke was made in the valley, and the
lookout at the inlet of the pipe on the mountain spur shut off the
water. Over each joint in the pipe was placed a cast-iron sleeve or
band, weighing 300 pounds, and within this sleeve was poured the molten
lead which served as packing. In all there were used 1,475 or 442,500
pounds of these sleeves, and but three out of the whole number proved
faulty, and failed to sustain the strain brought upon them, and of
12,640 sheets of iron used in the pipe, but one bad one was found. As it
would have been a great task to test each section of the pipe by
hydraulic pressure at the manufactory, the engineer proposed to bring
the whole under the required strain at once, after they were put down.
He began the pressure with a perpendicular height of 1,250 feet in the
column of water; increased it to 1,550, to 1,700, and finally to 1,850,
being 130 feet more than the pipe would be required to sustain when in
actual use.
During these experiments, men were stationed at the inlet of the pipe,
at its outlet on the summit of the Virginia range, and at various points
through the valley, as lookout men. They made their signals by means of
a smoke during the day, and a fire by night—a trick learned from the
Piute Indians.
As the water came surging down through the great inverted siphon from
the elevated mountain spur, and began to fill and press upon the parts
lying in the deeper portions of the valley, one after another the
blow-off cocks on the crests of the ridges crossed, opened, and allowed
the escape of the compressed air. Compared with what was heard when
these cocks blew off, the blowing of a whale was a mere whisper. The
water finally flowed through the pipe and reached Gold Hill and Virginia
City on the night of August 1, 1873. Early that evening a signal fire
was lighted in the mountains at the inlet of the pipe, showing that the
water had again been turned on.
As the pipe filled, the progress of the water in it could be traced by
the blowing off of the air on the tops of the ridges through the valley,
and at last, to the great joy of the engineer and all concerned in the
success of the enterprise, the signal fire at the outlet, on the summit
of the Virginia range, was for the first time lighted, showing that the
water was flowing through the whole length of the pipe.
When the water reached Virginia there was great rejoicing. Cannon were
fired, bands of music paraded the streets, and rockets were sent up all
over the city. Many persons went out and filled bottles with this first
water from the Sierras, and a bottle of it is still preserved in the
cabinet of the Pacific Coast Pioneers.
Previous to the laying of this pipe for the Virginia and Gold Hill Water
Company, the greatest pressure under which water had ever been carried
in any part of the world was 910 feet. This was at Cherokee Flat,
California, and was also under the supervision of Mr. Schussler.
In 1875, the Virginia and Gold Hill Water Company laid a second pipe
alongside of the first. This has an inside diameter of ten inches.
Instead of being fastened with rivets it is lap-welded, and is the
largest pipe ever made in that way. As there are no rivet-heads in it to
produce friction, it delivers the same amount of water as the larger
pipe, namely, 2,200,000 gallons per twenty-four hours.
[Illustration: GOLD HILL—LOOKING NORTH.]
Previous to 1875, the supply of water was principally obtained from a
stream known as Hobart Creek, but, in the year named, the works in the
mountains were extended by pushing the supply flume through to Marlette
Lake, within the basin of Lake Tahoe, a distance of eight and a half
miles, and a total distance from Virginia City of thirty-one and a half
miles. In order to reach and tap Marlette Lake it was necessary in one
place to run a tunnel 3,000 feet in length under a dividing ridge—the
ridge forming the rim of the Lake Tahoe basin. Marlette Lake covers over
300 acres of ground, and in the middle is 30 or 40 feet in depth.
Connected with the works are several reservoirs that hold from three
million to ten million gallons of water. Signal fires are no longer
necessary along the line of the works, as there is now set up a line of
printing telegraph, with numerous stations between Virginia City and
Marlette Lake. Marlette Lake lies at an altitude of 1,500 feet above C
street, Virginia City, and the water is brought in at such a height
above the town that it can everywhere be carried far above the highest
buildings, and streams from the hydrants are thrown with great force and
effect in case of a fire occurring near them.
There is now not only an ample supply of water in the city for all town
and domestic uses, but also for the boilers of the many hoisting works,
and for use in the several mills where the ores of the Comstock mines
are reduced. The cost of the water-works was over two million dollars.
[Illustration]