The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-11-08

up towards the top of the chasm
Suppose there should be break in
that penstock half way up?" The ques-
tion is a natural one IN TINS place ana
amid these surroundings.
The guide laughs heartily, Every
body that comes down here asks that
question" says he; now there amt
no danger of that, but if it should
mind I say if it should happen towel,
mebbe you've seen drownded rats; we'd
be lucky if we come out of it looking
as well as that"
STOPPING down, the guide raises a big
| trap door and we look into the seeth-
ing flood that d3shes past our feet in
more furious haste than the waters
at the foot of the natural fail. Be
sides, running parallel with the pen
stock. rises a great shaft to the bot
tom of which the turbines are attached.
There are two of these turbines, enc
placed just beneath the platform on
which we stand and facing down, the
either Is feet below, ON the lower end
of the shaft, facing up. Into the space
| between these two big water wheels
; the released water of this miniature NJ
agara plungwes and, dashing past, they
send the great shaft spinning at the
rate OF $50 revolutions per minute.
1t has been computed THAI 430 cubic
feet of water pass this point where we
are standing every second and the
question that naturally occurs to the
lay mind is, What becomes of this
flood that hurls itself seemingly into
the center of the earth?" AS a matter
of fact, to furnish an answer to this
question cost the largest expenditure
of time and money of any single item
in the work of the Cataract COnstruc-
ton company. The answer is found,
however. in the Niagara tunnel which
is simply a long Ga1l-race to carry the
waiter that has once been used back
to the source Of its supply. In the old
fashioned waiter mill the head-race was
the important and costly part, while
the tail-race required comparatively
little attention. But here the cOnCli-
tions are exactly reversed. The build
ing of the hedd-race, represented by
the canal, was. an easy matter beside
the construction of this subterranean
passage The tunnel is more than
mile and a quarter long and runs O.
rectly beneath the business portion OF
Niagara Falls. For most Of the way it
is channeied through solid rock and
the work of excavation and OF lining
the passage way with br-ck-WOrk
was difficult and hazardous. 1t COS
men as well as money to attain this
engineering triumph and many lives
were lost during the building of the
tunnel The tunnel was begun at the
point where it empties into the river,
known as the Portal" which is almost
directly beneath the new suspension
bridge and a short distance below 'ste
fails Th@wOrk was begun here in the
summer Of 1880 and il was three wears
later that The drill finally pierced the
last thin wall of rock and entered the
excavation at the foot of the wheei-pit
To one not up in this kind Of work, i.
seems a remarkable thing to be able to
-J--
that you come out within a few inches
Of the point aimed at, but the engineers
themselves assure US tlat this is moth
ing. But TO turn aside from the "POr-
tai" where the waters which lash them
selves into such fury at the foot of the
wheel-pit slip out as quietly as though
they belonged to a country brook ana
go hack to the Wheel-pit itself.
The big shaft which is still turning
$50 times a minute is a steel tube IS
inches in diameter and hollow, except
where collars are fitta1 on to hold it
in position and keep it steady. Here
ii is II inches and solid. If we follow
the shaft up to daylight again, we
ind that it projects into the power
house and is surmounted by the revolv-
ing field of the dynamos itself Here
is where the power, which has thus far
been in the form of direct motion, is
COUN e lGQ 1IAO G-CClIlC lOIce anu mere
the understanding of the uninstructed
is apt to stumble in following the trans
formation which we set out to trace.
The great dynamcs are marVels of
power. each one of them capable of
turning out 5000 horse power when the
turbines down below attain an effic
iency Of only 10 per cent. The armature
of the dynamo is set on end so that its
axis is perpendicular instead of hori
zontal, and with its cover it surmounts
the shaft like a huge cap, as shown in
the accompanying illustration. In front
of each dynamo stands the governor, |
an interesting and complicated mechan- |
ism in itself, which controls the move !
ment of the big cylinder. Behind the
four dynamos, already in position, on a |
raised platform in the center Of the /
dynamo room, is the switchboard ar
rangement, where the mighty current |
from these great machines is received !
and sent out in whatever direction il |
may be required.
The system in use here in generating |
the electric current is what is known |
as the Tesla Polyphase Alternating /
Current system. Each generator de- |
livers an alternating current to each |
$50 apart, that is, each current atains |
its maximum value when the value OF
the other is zero. The direction of the
current is reversed 5000 times per min
ute. The current thus produced is con-
veyed through heavily insulated cables
to the switchboard shown in the illus
tration, where one or all of the gen
orators may be connected with the ex-
ternal circuits which convey the cur
rents to the consumers.
From the switchboard heavy lead
covered cables carry the electric cur
rent through a subway and across the
bridge TO the small transformer house
on the other side of the canal. Here
the wires which carry the current in
tended for nearby consumers enter a
conduit, but as it is the long distance
current that interests us, we will fol
low it still further. The wires which
,cakrk thRs current enter what are
called "step-up" transformers, where
the current is converted into one of
high potential, e. g. of 10000 voltage
for transmission. Then the current
leaves the transformer house on
heavy wire and is fairly launched on |
ifs long journey.
1t was for some time a debated ques-
ton whether this high pressure cur
rent could best be transmitted along a
wire strung on poles or through a con-
1uit buried in a trench. 1t was finally
decided that poles could be used with
safety in crossing the open country
but that in the city it would be neces-
sary to bury the wires. Accordingly
from the power house a long line of
poles carries this chained lightning