New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-08-21
THE ELECTRIC FURNACE.
A WONDERFUL CONCENTRATIONS OF
HEAT IN A NARROW COMPASS.
From The Boston Transcript.

Professor John Trowbridge writing about the
electric furnace. says: There have been three
distinct eras in the practical applications OF cleo
tricty. The first characterized by its use
I'm telegraphy the second by its application Ia
lighting. and the third by its employment IN
the transmission of power. We are now enter
ing upon fourth era, in which electricity may
be said to pay back its debt to the energy which
produces it by generating heat in the electric
furnace.
This use OF electricity has already revolution
ICED certain processes in the arts. The heat OF
the furnace is generated by an electric arc such
as in the or the arc HghtS on our
city streets. This arc is produced by current
OF electricity flowing through the intensely heat
ed air between two pieces or carbon Inc tur-
mace consists OF a box or parallelopiped OF line
stone. having cavity Of similar shape cut into
It. The electric current is led into the cavity
by means OF pieces. terminals or electrodes az
they are technically called. OF hard carbon which
pass through holes cut in opposite sides OF the
cavity. Then the oxide Of the metal which one
desires to fuse is mixed with carbon powder
and is packed around the carbon terminals and
IS reduced by the great heat developed 10y the
voltaic arc. produced by the electric current
flowing through the cavity from one carbon
terminal to the other. In this way aluminium
is produced. and in a similar way carbide 81
lime. which on being dropped into water gives
forth the gas acctylcnc in great quantity
For scientific experimentation the ca.ity holds
a small cruchr which is composed OF Il mixture
OF carbon ard maSnesia. In this crucbe are
| placed tn" substances which are To be melted.
| There is no metal which has not been fused by
| this furnace Even platinum and iridium both
! OF which remain solid in the hottest furnace.
| such had hitherto been used. melt like
| wax IN the electric furnace.
| Sometimes IA carbon tube is fixed in the lat
| ter furna"c across the line Of GiT elton IF the
| carbon terminals. or. in Other words. at right
| angles 10 them. and 50 placed that il is about
| onc-half an inch below the intense voltaic arc
and about the sam" distance from tho bolt m
| Of the limestone cavity. In this carbon tube are
! placed the substances which are to be heated
| Material can hc introduced into ono end of this
tube. and after it is heated can be drawn OF
10y tipping tn" tube. without stopping the
| rent in the furnace.
In order to produce diamonds iron is melted
with Il larg" quantity Of carbon powder. and
p Hhcn the mixture has attained Il high Temporal
/ tur"-ovcr COCO degrees Fahrcnhct-t is sud-
denly plunged into cold water bath of
molten lead The lead being better conductor
II heat than cold water. more suddenly de-
7 privcs the mixture 81 it, heat ON examining
IN" Stag small colurloss crystals Of carbon are
found. which are identical in their properties
with natural diamonds
The rlcctri' furnace has the grea: advantage
over other furnaces in it, power to lpcazc the
heat III narrow compass. and the amount OF
heat "" can produce in such furna zee is aim st
unlimited An amount Of heat energy equiva-
lent to- eco hors' power has been produced in
an electric furnace cavity which was not larger
than an ordinary tumhl,r OF water. Sometimes
"A powerful magnet is used to direct the electric
are up"n certain region in the furnace.
magnet has the property Of attracting or re-
polling an electrical current. and the voltaic
arc i'm the furnace lS such an electrical cur
rent. With su,@ an arrangement namely. A
/. yoltac are and a magnet We have practically
Il powerful hIoWppc. which melt; glass and the
. metals like wax and and VaporiZrs even tnc lime
walls 81 the furnace. Their" ar" "A number ~ cleo
trc furnaces AT niagara Falls. which are used 10
. reduce the oxides II metals and To form such
, substances a carbide Of lime from which
! acotylcrc is generated. and corundum, which
ed . ending agent the arts.
/ have said that the temperature obtained by
the electric furnace * not FAR from 5000 de-
/ rrccs Fahrenheit since all substances which
! are available for making thermometers are
! melted los such heat tn" question naturally
arises how can We measure such a high tenn
rcraturcr II must b." confessed that We cannot
| r.. tsurc II accurately and can only form a.
estimate This estimate can 10 made 10y cleo
trical means Suppose that measured guam
titv - electricity IL sent through a thin strip
! q platinum or flamcnt similar To mat In an
Edison lamp tn heat riveA out 10y tn" glow
INK platinum or carbon hl.trnent depends upon
/ H." Iulntity Of electricity which We can force
/ through II "" can measure this quantity very
/ accurately and from II determine the amount
/ of heat given out 10y the ildmcnt. w" Know
that 4 STRIPE platinum nd hot has tcmpcra-
tur. In tn. nrighhorhood ~ l.N'c degrees Fan.
r.uhcif and when 10 * white hot n tempera-
turc - - inp degrees. suppose That We keep
the platinum strip rrd hot 10y Il known current
Of electricity and pat a delicate Thermometer
/ M "A distance - thrc" OF four feet from the
sirlu and rad it, indication. We VIII then
.Xr,ns. III, sam. thermometer to an electric arc
lmu which represents the electric iui mace.
and mol, u unit It reads the same ~ It do
when II WAS exposed t. ~" red hot platinum
strip w shall ind that We must m"N" ne
th.r-.ofi.,i,r fnu.t fur h"i from inc 'l''H :.
furnace. anG thuS moving ~" tchI''"''''
;h. rod hot strip ai.f tn relative distances we
can ascertain approx imatcly the temperature