The sun. [volume] (New York [N.Y.]) 1833-1916, 1901-02-10

-"
to- hnicsl triumph u Wa In q .sns" 'hs
culminsi ION ~ many wears ~ development,
t~.sinnias 9TH nv. early attempts imnie-
diai~lY 'oliouins Isfidavs discovery
slr~ady ~f~ferr~t 80 Ursnnrr rDt~'rI''si
h- revolving tfnaturs ~ q .nft iron wfs
rina ufpn ~hich rins q a~Ti-- ~ small co'l'
~ ln-ulsi~i or. s.r~ voipd ip .Irr~s-tv"
rsdisl plans Thes' rolls rrrp aU r"n-
n~-t~t into , continuous VIZ" and from
tho Iunsiiota ~ Nv. ruiis ms srh anr'hef
eonn~ctlnn. .sr- ,ah~n ta . fanss " e"rf~r
bars lpsulsi~t from ss'h o'hsf consul
'u'ins he ~ommu','or IN isfl Npn Hsfn"f
,rsne-h IN R.rtin. modified ih~ rms sind
ING ~ gtsmma and pfpItc~i The ifnm'
riHdios shirh svpide'i tho n"o"-'y f"f
threading rifs through tho c"r'f" ~ w"
iron rnx - In tho Gfamm~ construction
Tho srveral 0oiis - th~ drum 's"r" s'il
cuunr, TOD o. IN Gfnmmo e mt'hine u" 'hH
sI'Ho.-irr atfits - The oummutatnf
IN musisrn dvnnmo- AMI motors Tho anna
tufr. usually constructed - sheet iron
puu'hiusa ID. ring srh projections a. IN
rnrrinl'nia ntrhiro. AID tha rri7 ~ viva
afe ln mHaf .is.s wound separately and
''''N NNNNf .'N I'M. .NN ~ '" w .
lrrtious. constituting IN 'a~' = form ~
drum winding IN tho early 10 = fcv
Grtmme rng AMI Sism~ra drum machines
bat been applied 90 'ho running ~ arc
ligh's ono machine fur each light There
w,rn BHap aHuo ttlnwn ml" hines in uaa
tnr ,l... rurll.ug
IN al IJ namu- In practical ne" IN" our
trufa Witch ,rn generated ~" Alternating
currents, ~ They are called such currents
are aharr,tsryed 10Y rapid changes - d'r~'-
ton ~ rpyrr-al- Those occur times
psr ae,urI. and whom such currents ar" 10
ho W ia into continuous currents flowing
ln one direction the machine l. provided
vIfha oommuta'or FOR connecting the coils
10 the Circuit. 80 that Tho current will always
flow d. IL In the same direction. Great num-
b.rs ~ dynamoz, however, are used without
comuutaiors for changing tho direction ~
their currents In such machines IN" CIR
cult receives. instead Of continuous currents.
waycs ~ current or alternating currents
A with sound. the waves have a pitch, 1 =.
they follow cach other At a certain number
Of times per second. In usual practice there
will lie from rs waves. which would be a how
period, up TO $50 or more per second. but
machines can be- constructed 10 produce
alternating currents Of many thousand
waves or cycles as they are termed per
second for special uses. When an alter
Mating current flows from a line there are
times when the current Is changing from
one direction to the other and when there
Il actually no current. and these are called
the zsros, or dead points Of tho current
Much Of the machinery developed In later
years has been Of the alternating current
type, generators. motors, dc. utilizing
these rapidly reversing currents.
At the Centennial Exhibition. held at Phil
adelphia In 1879. but two exhibits II electric
lighting apparatus wero TO be found. or
these one was tho Gramre and the other
the Wallace-Farner exhibit. The Wallace
Farmer dynamo machine Is a type now
obsolete. 1t was not a good design. but
the Wallace exhibit contained other eX-
afnplp~ rejecting great credit upon this
American pioneer In dynamo work. Some
Of these machines were very similar la con-
struction TO later forms which went into
very extensive use, Ia largo search
lighta occasionally used la night illumina-
ton during the exhibition were operated
by the current from Walldce-Farrner ma
chin4. The Grammo exhibit was \ re-
mukable exhibit for It's time, Though not
extensive It was most Instructive. There
we're found In II II dynamo running an arc
lamp, a large machine for electrolytIc work
such "a electroplating and electrotyping.
and. most novel and interesting Of all one
Gramme machine driven by power was
connected To another by a pair OF wires and
the second ran Hs n motor. This In turn
drove a centrifugal pump and raised water
which flowed Ia "A small fall or cataract,
A year or two previously the ramm ma
chine had been accidentally found TO be rs
excellent an electric motor IA 1t was a gen.
Grating dynamo. The crude motors OF
jacob. Froment. Davenport, Page. Vcrgnes.
Gaume and many others were thus rem
dered obsolete at Il stroke. The first pub
lc demonstration OF the working OF one
Gramme machine by another was made by
Eontaine AZ the Vienna Exhibition Of 1873.
Here. then. wW a foreshadowing OF the
great electric power transmission plants OF
to-day: the suggestion Of the electric station
Furnishing power as well dS uHnt, anu 10
less degree the promise OF future railways
using electric power. Replace the centri-
fugal pump OF this modest exhibit by a
turbine wheel. reverse the flow OF water
so as to cause II to drive the electric motor
80 that the machine becomes a dynamo.
and in ike manner make OF the dynamo q
motor, and We exemphfy In a simple way
recent great enterprises using water power
for the generation Of current TO be trans
mitted over lines ia distant electric motors
or lights.
The Centennial Exhibition also marks the
beginning, the very birth, it may be said.
OF an electric invention destined to become.
before the close OF the century. a most
potent factor In human affairs. The speak
ing telephone Of Alexander Graham Bell
was there exhibited for the first time To tho
savan,s. among whom was the diStin-
guished electrician II scientist. Sir William
Thomson. For the first time in the history
OF the world a structure Of copper wire
and iron spoke to a listening ear. Nay,
more. il both listened TO the voice of the
sneaker and repeated the voice at a far
distant point. The instruments we're.
moreover. the acme Of simplicity. Within
N ,,or ,nouy a hoy Ind Cop.truCteI a mir