Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1895-10-31
ELECTRICAL NOTES.

The following comparison, due to
Palaz. will be useful 10 electrical en-
gineas I'm prescribing bhe advantages
of electric lighting from the stand
point III Goodness The figures quotaa
are relative to a given quantity OF
light: Are light, 4; incandescent Light,
IA; kerosene, a1gand burner 33l; gas,
ah,g:ind burner, $50; candle. 413; gas
butterfly buine". oil. The heat ques-
zion 4 a very important 0ne, but ~
ii as no,laa.lg compared With the ques-
tiom of vlfataa atmosphere. In Tins
res,tye4t. IF course, electricity com
pares still more faymably with all
other sources of Artificial light.
I'm paper read before dhe Royal !
society sOn the effect of preSsue OF
he ,slmomel!ng Gas On tine tempela-
t,lre Of tine crater Of an eleat1ic are
nght." Mr.. ". u. wilson states tihat
az late Years 1T has often been as-
suncd tlmt the temperature Of the
crater forming the positive pole OF
tho elef1r.ic are Is that of BOILING car
bon. The most modern determina-
ttCrts give tIhat point as about 3,5oo
degrees 10 $500 degrees G. In order
~ investigate whether Increased pres
sure M tire gas surrounding an cleo
mic are would raise the temperature
of the crater he usPtl a strong cast
iron box. in the interior of which an
electric arc light could he ma1ntained'
Bv increasing the pressure Of file gas
m the box Bhe temperature Of inc
CRATER Ii considerably lowered instead
of being RAISED, and the experiments
tseen 10 sllaw tlat the temperature OF
tlpe crater, like chat of flament in
In fncamlescemt lamp depends ON ROW
much nj is cooled by the surrounding
otnoSuhere and NOT On its being the
tempelaitllre nit which the yapor OF
carbon lsis tire same pressure as ulle
surrounding atmosphere. That carbon
volntlfzcs It'll some form ut compaaH-
tive,y low temperatures seems likely
from the way In which tlle carbon of
.ncaneleSeent lamp filameats Is trans
ferred to the glass. The pressure OF
the vapor of carbon i'm the arc may
consequently be very smaM, and fur
thpl. II would Se0m that the suppose
tlon Of high plessureS IN THE lar
Philosophers is NOT borne out by these
experiments. and thhIt carbon may eX-
i4t There i'm the solid form ait very
nigh tempGNfltiy- although 1.-THE pres
sures are comparatively how, IN two
pole dyamos the proportions Of ring
armatlnes vary from Il length equal
ro one-half dhe diameter Ito a length
equal Ito cine and one-ha.lf dianetelS.
lit b common 10 make th. length equal
10 .he diameter For drum allmatlres
the length sometimes eqmls enc and
one-la1f dlama.1S and sometimes
tlm'ca tlHlineaels 1t lis common to fad
the length equal ~ two dinmerer9.
Gitlta Iertha heated III hot water
~ about loo degrees r. becomes plas-
t.r. and VIII take fine impression
with sight pressure When gTTa
porcha is seakeal for few hours in
hcn2o,e on nallptha it becomes
swollen, and If it N then dipped IN hot
waiter, III becomes N, Plastic thait Ii
~ ~ y ~ AANtHlf NAtii NAAAsHA M NN4s 3
fragile aud delicate objects, adapted
to electrotyping.
THE cotton thread used for The fila
menns of ineandcScent lamps is parch- |
meniizel before carbonizati0n by
passing it slowly through a solution
~ >ulphllric acid two parts, waiter one
liai'r and finally washing 1t in water
uatM every particle Of the acid is re
moved The parvhmentized thread, !
after driving, Is reduced TO n uniform
diameter by drawing 1t through dies,
after the manner of wire drawing.
4 rhcmopile, for experimental pun
poses, may II made If pieces Of Ger \
man silver and copper wire, twisted .
ana halal-Soldered at the ends. per /
forming series of pIiHs, and arla1g
ing The wires thus Joined In the fern !
of many pointed star SO that the I
German silver ana copper wires after !
nate thc ends 81 the sei'ies being left (
unconucctel Tie inner points Of the <
star arc hcstel over 4 Kerosene lamp.
The wires may ~ No Is and six
inches long
THEY'RE STILL. IN THE FIELD,