The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1896-11-15

dence that there is anything wrong
with the huge revolving shafts or the
giant penStocks. The walls of the shaft
for most of it's depth, are merely the
natural rock standing just as it was
drilled out from these cavern walls
and small streams of water are running
at every little distance. 1t Is, indeed
wet weather. The floor Of the cage Is
a puddle of water, and one can hear
the drops pattering upon the floor.
Outside a fine mist seems to fill the air.
All the time one is sinking further and
further down until the roar of the wa
ter escaping at the bottom, which at
first came up in an indiStinct murmur,
now sounds like the rushing of a hun
dred angry torrents. The elevator
comes to stop, and the guard throws
open the door with a shout
ed direction-at least it Is prob
ably shout, but his voice Is
all but drowned by the roaring all
about us, and makes no more impress
sion than would the splash of g. pebble
thrown from Prospect Point into the
depths of Niagara's chasm.
One stops outside and stands on a wooden
platform which covers framework of steel
Orders. These Orders are fitted securely
into the rock, and on them rests the weight
tons in all Down here, far below the earth Ia
surface with the roaring Of the tempest In
his ears, and its blackness all about, the
feeling Of awe that display of mighty nat
ural power always inspires is strong upon q
man. One looks up, but see only the
electric lights, like twinkling stars, far up
toward the top of the chasm.
Suppose there should be break In that
penstock half way up?" The question Is
natural one in this place and amid these sur
roundings.
The guide laughs heartily. Everybody
that comes down here asks that question:"
says he, now there amt any danger OF that
but If 1t should-mind, I say IL 1t shoulH
happen-well, maybe you've seen drowned
rats; we'd be lucky If we come out Of 1t lookin'
as well as that"
STOPPING down. the guide raises a big tran
door and one looks into the seething food
that PUSHES past his feet in more furious haste
than the waters at the foot of the natural
faIl. Running parallel with the big penstock
rises great shaft to the bottom Of which
the turbines are attached. There are two
OF taese turbines one placed Just beneath the
platform and facing down, the other fifteen
rect 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, Niagara plunges, and, dashing past,
sends the great shaft spinning at the rate Of
2oO revolutions per minute
It has been computed that 43O cubic feet Of
water passes this point every second, and tine
question that naturally occurs to the lay mind
is, What becomes of this food that hurls
itself seemingly into the center of the earth?''
this question cost the largest expenditure Of
time and money in the work Of the Cataract
Construction company. The answer is found.
however, In the Niagara tunnel, which Is
simply a long tail-race to carry the water that
has once been used back to the source of its
supply. In the old-fashioned watermiIl the
head-race was the most important and costly
part, while the tail-race required compare
lively little attention. But here the conditions
are exactly reversed. The building of the
head-race, represented by the canal was an
easy matter beside the construction Of this
subterranean passage. The tunnel is more
than mile and quarter long, and runs
directly beneath the business portion of
Niagara Falls. For most Of the way 1t is
ehannelled through solid rock and the work
Of excavation and of lining the passageway
with brickwork was difficult and hazardous
1t cost men as well money to attain this
engineering triumph; 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 short distance below the falls
The big shaft which turns $50 times a min
ute, is steel. tube thirty-eight inches in
diameter, and hollow, except where collars"
are fitted to hold 1t In position and keep
it steady. II one follows the shaft up to
daylight again he finds that it projects into
the power house, and Is surmounted by the
revolving field Of the dynamos itself. Here
is where the power, which has thus far been
in the form of direct motion, is converted into
electric force, and here the understanding
of the uninterested is apt to stumble I'm fol-
lowing the transformation.
The great dynamos are marvels OF power,
each one Of them capable of turning out 5000
horse power when the turbines down below
attain an efficiency of only rs per cent. The
armature OF the dynamo Is set end, SO
that its axis IS perpendicular instead of hori-
zontal and with Its cover surmounts the
shaft like huge cap. In front of each dy-
namo stands the governor, an interesting and
complicated mechanism In ITSELF which con-
trolls the movement of the big cylinder. Be-
hind the four dynamos. already in position,
on a raised platform in the center of the
dynamo room, is the switchboard arrange
ment where the mighty current from these
great machines is received and sent in what
ever direction it may be required.
The system in use here In generating the
electric current is what Is known the Tesla
polyphase alternating current system. Each
generator delivers an alternating current to
each of two circuits. The two currents are
$50 apart, that Is, each current attains its
maximum value when the value of the other
is zero. The direction of the current is re-
versed 5000 times per minute. The current
thus produced is conveyed through heavily
insulated coolies to a switchboard, where one
or all of the generators may be connected
with the external circuits which convey the
currents to consumers.
From the switchboard heavy lead-covered
cables carry the electric current through q
subway and across the bridge to q small
transformer house on the other side Of the
canal. Here the wires which carry the cur
rent intended for nearby consumers enter
conduit. but the long distance wires enter
what 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 its long Journey.
1t was for some time debated question
whether this high-pressure current could best
be transmitted along wire strung on poles
or through conduit buried In a trench &c
was finally decided that poles could be used
with safety in crossing the open country, but
that in the city it would be necessary to bury
the wires. Accordingly, from the power
house long line OF poles carries this chained
lightning on its journey toward Buffalo, It
was found. however. that the ordinary glass
insulators used in telephone and telegraph
service were not equal to this work and
heavy porcelain insulators are used instead
on all the poles along the line. These caps
consist OF four layers with air passages be-
pose.
win" --Robert Earl