, 1879-01-30

snry 10 rcsort to some dcvlcc whFc,, viii krcp
rlm Inventor frst sought to overcome til. DIM.
c1lsty by makinE the rapidly y.bnrninc tartln
proportiona!ly Thick. 1,y surll compcnsat'nE
arrangement the light Har fndocd greatly I'm.
proved, hut It wns still far from satisfactory.
.fhe difficulty WINS ultimately t'vercone by send
Ing thu eicrtrtc current atternntcly ta,.utE ilic
two cArlon rods, 80 that this poie which at one
moment is positive bccntncs the next moment
Negative. T1'p carhoiss arc thus kept Uniform
In length: the wicks arr always opposito cact,
other, anil the light htcnnles remarkably eteadv.
The Ja1loelkotY light IA tncloscd III !. Elohe
Of nlsftno glass, which snlaaucs tho dazzling
pure and soft light, though at tile loss ri
about one.hatf the Illuminating power nj t1.c
naked candle. Each opal Eotc CONTAINS fot1r
candles. but only one ot these Is alIRht at one
time. As each candlG burns for about a1l hour
and half, The falr suffice for the ct,t!rc eyelt-
Inc. Al soon as one candle Ia burns down tho
current IL shunted, either manually or by .at,
automatic cnn'tnutstos, to the next candle.
EACH camille IN the lantern Is mounted 10 brass
tube, securely held upright In palr Of laws.
aih1 Is connected with thc elestruinosor by
means Of = cable Ut seven iinnelcopter wires,
which run down the hol'ow. ahutt Vi tllc lamp
enrare draiuagc-plpes.
It IS tic JabiocbkoH candle which has hitherto
been largely used In ParlI TO Illuminate not only
come OF tho pubtc thnroughfaree. such as the
Place Do rOpcrn. but a!so the interior Of large
buildings, such rs the Magaslns Ju Louvre md
The new f1ippodFomc+ Il this light asc which
has been introduced into England ty t1sc Soelcta
Hcneralc dc I'Eleelrctte Of ruris, and Is already
uscd on the Thames Emban';Inuht, wllcro SUE
ceasfu1 experiments hnvs recently been nude.
THE ELEtTllC MACHINES.
70 obtain the ALTERNATING currents OF electric
'ty required tor ll,e dah1oc''knT ltghs II.
tirau,tlig has DEVISED n special modification Of
1tfA srr1l.k ttHNah1n machine. Ittt}n n
proRTcss towards tllc practical extension uf ccc-
trie lighting could lsc made as lonE as tho cleo
trtclty was grneratctl ty yultafc battery. But
after Fasaday' = a!scovesr OF es:tflcitY,
machines wrrc constructed for tho production OF
electricity by the rotation Ut nu Induction coil
IN frnnt 0f tile potcs at tiaCEct. llcre lie
mechanical force which Il expended in tho rota-
lion u the cofi, Or arlaature, hc.o,nes trans-
f1rmcd into electricity; whIle IN Hue ralyanic
battery It IL tic expenditure of chemical forec
TINT gives rlso to the electrical energy.
by the substitution Of cleetro-sslagncts for or
dinary OF so.called permanent tnaysluls a great
step ivas made In the construction u these H1a-
cliincs, When N clcctro-nlhgnet has onre been
n,acncttzca 1t per1nnnentlY retains su,aif
amount ot magnetiem: and It WAS found almost
Wl,ea.stone, and by Mr. Varley ti,at II coil ho
caused to revolve In front bf IN cgct ctru-lnaynot
this residual magnetism will induce current In
the revolving arn,aturc. The current thus pro-
lticcd ls then used to Increase the tha0nctlsIn Of
the electromagnetic BY being sent through tho
wire surrounding the magnet. TIE stronger
magnetism now reacts on tie coil a,ul induces
alorc powerful currents, which In turn strength.
ell The magnetism, And thus tl,crc is continued
acsion and reaction between the tnaenct md the
armatusc until ultimately very powerful eur
tonts arc obtained. Ille machines which mrs
constructed on this principle Of mutual rein-
electric machines. Each separate light
Il said to require for It's production unc
horsepower Of On engine. Ihus every Six
teen Jablochk0ff, canlics In Paris aru
served oy single Graa.nc machine, which
power; for this expenditure OF oow er most
brilliant light is ootssnci, but much Of It's tn-
tcnaity is lost ny the opal globes which arc ncc-
Jablochkon candle, representing oue-lorsa
power, II said to havs tlc photomctre vaiue Of
too standard cnndfes, but the globe reduces IN
elective l1ghttn0-po"er so something lfks 3oo
candies.
REGENT IMPROVEMENTS
Various other forms Of tho electric light are
dcscribed, hulhnE them that OF NJ. llaptotf, In
use 10 tho Office Of the Londen I;n,es. mud the
limp devised by Mr.. Wcrdcrmant', in which tho
light Is produced whe tho cArbons arc In direct
contact, atul. which promises exceptionally
vntuable results. Another uovc1 form, Is tho In
ventlon Of Mir. Wallace. of' Ansonta, Conn., ih
which the casbons. iusteal Of bcIuG eitlcr points
or dtsfss, take The form Ut Rectangular Slabs.
nEnc inches lung uni thtce fl breadth, Ia con-
tnct along ono cdge. by thts arrangement It Is
e!aMnea tiat a'nant 1 @! un"olni in.eos,ty ean po
ma,ntMhc4 ~ ~ hours w'.no1a' ca@nEc a... "
rortant experiments Of PTofs. Thompson a,A
lio'ston, O. lalane!ph'a, ~ "H',zME ans spa,sk
u haoxcn .s' eurlsnu: wy, III cuAeuS'on' e''e
"I.eL III 1l,S 4t;Me'em IT, t,fn,H snsa: -,
e,eGtrS '!ium,nation. @ Which nave eecn briefly as@
scl1ueo :" sMs aaaSe, '1 p5n'sp ~ ace9hr!iisn,
. nMuLS Ut teas nusssssus, 'n tnt Ha."s opcet
mNSM nus ~ o4tSu plofsa stunn,!nE'ulu:R -
@ yanase M Il ills Electric rht iie. in ia i;s excessive