New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1899-02-26
THE NERNST ELECTRIC light.

ADDITIONAL PARTICULARS REGARDING AN
IMPORTANT INVENTION
The Tribune briefly mentioned the new electric
Hight Of Professor Walther Ncrnst several
months ago. Further Information on this sub
ject has recently become available. The inven-
tor utilities the principle Of incandesccnce that
is applied in the Edison lamp. But the Amer
lean and German devices differ in several re-
spects Edison incloses his hlament I'm globe
from which the air has been exhausted. Nernst
exposes his TO the open air. The Edison horse
shoe is burned out I'm a few weeks and Is worth
less The whole lamp must then be- unscrewed
aud discarded. the thread cannot be replaced
by.the user The piece which gives light in the
Nernst lamp IS accessible and can be removed
when II becomes useless. and new one can be
substituted with ease. The Nernst hament or
rod Is long lived. But when renewal IS neces-
sary ii costs but a trile.
The most radical novelty Of the German lamp
IS the material used for the hament. At times
during his experimental work Nernst has en-
ployed magnesium. thorium Ghe substance
largely one Of the constituents OF the Welsbach
mantle) and other materials sngly and In com
bination. The exact composition Of his latest
rod IS a secret. but is probably made up Of rare
metals or. rather, the oxides Of these metals.
Of glow produced 10y different elements when
brought to Il state Of incandescence The awful
glare Of the calcium light reveals the eXcep-
tonal character Of lime. for instance. in this
regard. The brightness of the photographers
flash light powder depends upon the presence
In T. Of magnesium And Wesbach found rare
earths which would produce even more brilliant
illumination when heated. Nernst has probably
utilized these in place of the perishablc carbon
thread Of the old incandescent electric light
The luminous pencil OF his device is about an
inch long. and q sixteenth of an inch I'm diane
ter-or tribe more slender than parlor
match.
The new lamp has one other original feature
II IS not possible TO light IL by simply turning
the current on. az with Edsons apparatus. The
rod. which eventually emits dazzling light by
reason Of It's heat Is a poor conductor Of cleo
tricty when IL ~ cold. 1t IL necessary, there
fore to heat II first. and then turn what may
for convenience be termed the lighting current
The preliminary work * also done by electricity
but with separate current.
Hidden away under a reflector attached 10 the
lamp Is small coil. like that used 10 heat an
electric When the lamp is out Of service
and quite cold the rod Of magncsa and thoria
Nhe oxides ~ magnesium and thorium) is i'm
contact with this coil. having been drawn up
automatically against il. The first effect OF
turning the switch. or button Of the lamp Is to
admit the heating current TO the COIL and thus
20 heat th- adjacent rod. TIE latter having
become good conductor all Of sudden. now
allows the lighting current to flow through IL.
And "a soon ms this occurs the rod drops down
into different position. and remains there for
purposes OF illumination. But when the lighting
current can flow II automatically shuts off the
heating current. The apparatus required TO per-
| form these functions Is not SO complicated as
one might suppose from the description. but 1t
certainly makes the thing less simple than the
! Edison lamp.
Professors Perry and Ayrton. OF England. who
are high authorities In science. entertain great
expectations OF the Nernst light and think that
Il IL destined to occupy large field of useful
ness. 1t promises to make a distinct place for
! itself however and not TO displace either the
/ old lncandescent or the arc light.