The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1879-01-17
ELECTRIC LIGHT.
Interesting Interview with Professor
Draper on the Subject.
CURIOUS EXPERIMENTS WITH PLATINUM
The Difficulty OF Subdividing the
Light Solved by Edison.

AnOckinB at the door OF the chemical lecture room
in the University Building. the other day. the HERALD
reporter was admitted Philosophical and chemical
apparatus strewn about on every side Of the
BARE bleak apartment. making it suggestive of the
den of one Of the old achemists. Such ideas were.
however at once dispelled by the bright practical
face of Professor Draper who engaged in arrang-
ing the apparatus for his lectures during the present
term. The writer explained that he had called to
talk about some experiments made by the Professor
more than thirty years ago. The commissioners
who from Washington to examine into
Edison's patent for time found not
line on record indicating that anybody
had made experiments on that plan.
At last, in the Aston Library. they were
shown publication describing a series Of expert
ments made by Professor Draper at the period men,
toned. The writer spoke Of the fact to Professor
Draper and asked for particulars At first the Profess
seemed disinclined to talk but the recoections
brought up by the question seemed to be of pleas
ant nature. He seated himself in an armchair oppo-
site his visitor and, after moments distraction. he
passed his hand over his brow and turned the soles
of his feet toward the fire. Then looking about the
room he sald:-"I don't mind saying something
about the experiments to which you refer. believe
this dingy old apartment was the first in the world
that was illuminated by the method which Professor
Edison is said to have brought to perfection"
PROFESSOR DRAPER's LIGHT.
"How did you do it. Professor?' asked the writer
''well." he replied, ''there are as you probably
know, two ways of getting an electric light One is
by what is termed the interrupted method, where
there is break in the electric circuit and usually
the break is armed, it were. with pieces Of carbon
so that the current leaps from side to the other
and it gives an exceedingly brilliant At, light It is
of getting electric light abroad have been in this i'm
terrupted' way. If understand Edisons plan it is
,fs.Nrr
is, the electric current is made to run through
piece Of thin platinum, which becomes very
that were made before Edisons time on this con-
tinuous incandescent plan were made here in this
room. They were made in the period from 1S45 to
1S47, and this was the result published at that
tme:-As the electric current was sent through the
platinum by increasing the current it became hotter
and hotter At $500 degrees the light that the plati-
nun emits is thirty-six times great at 1000
degrees. Platinum melts at about 1000 degrees,
and when brought the heat up to that point
the light was sufficient to illuminate this room.'
The apartment is about thirty-six feet square, and
with high ceiling: The Professor exhibited to the
writer piece of platinum, with which he had fire.
qnently he said. lighted up the room that
could read in any part of it, The little piece Of metal
inch and third long. one.twenteth of an inch broad
and thin as tissue paper.
IF would allow it to reach the 1000 degrees
melt and, of course, that would finish the iumina-
ton. So 1 sought to find some point to which the
platinum could be heated to emit the light
without melting it. 1t happened that at that time
Colt of revolver fame, was in the University
building here He had found means to interest
Congress in torpedoes as implements Of war,
and they gave him sum Of money, think 1t was
$4,000. to carry his invention into effect He was
then living in the southwest corner of the building,
In the turret. Now Colt required very powerful
voltac battery in order to ignite his orpedoes and
so he made what Is termed nitric acid battery.
suppose it was one of the largest that ever made
He imported lot of platinum from Russia for use
in this battery. The battery would give an arc Of
circuit that spoke Of"
COLTS EXPERIMENT.. 8
"It must have produced y very intense light, Pro-
lessor ?"
Eyes, and Mr.. Colt was very much troubled with
his eyes in Consequence He told me that when he
the whole night long in that square pointing to the
snow-covered pathways Of Washington Park) suffer
ing from Inflammation of his eyes, caused by looking
at the flame. He bought an old ship-a brig l think
1t schooner-and carried her down to Castle
electric battery. blew her up. That was about the
first experiment that had i'll the way of blowing up
ships with torpedoes Well used to see great deal
of him ut that time. We conversed scien-
tfc matters and Colt gave me piece
of this Russian platinum. used it
in my experiments and with it produced electric
light vastly greater than had succeeded in getting
with the soft. common platinum: This was BECAUSE
it would bear heating to higher degree: quality
which attribute to the presence in 1t OF iridium.
"By the way" remarked the Professor IN paren-
thesis. there was rather interesting incident con-
nected with this Russian platinum. The Russian
government about that time issued platinum COIN
age but could not be brought into general use be-
Ural Mountains and in Brazil, that there po-
ltical reason why the other European governments
should not adopt it,"
'what kind OF coin does 1t maker? asked the
writer
ut makes the very best high coinage in the world.
You cannot fasify it or initiate it, but it is very ex-
well, to go on with the story. The strips of
platinum that Colt gave me would make afar brighter
light because they would bear much higher tenn
perature. But to 60 back to the light. The STUN
bling block in the way of its adoption for common
the fact that when you attempt to divide the
light you reduce its temperature. and when the tenn
perature is reduced you reduce the light enormously
the ha t from pnsu Sovo degrees
The light would only DO one-thrty-sixth OF what it
was before"
I'm what shape was the result of your experiments
printed, Professor p inquired the writer.
WHERE EDIsoN's MKisIr LIES.
tpss NJ aad rsaa0 OF ms
Among writer's on optics it has been desidcratum
to obtain reliable light of standard brliancy. The
foregoing experiments furnish an easy means of
supplying that want and give us what might
OF standard Dimensions raised to a standard temper
ature by voltaic current Will always emit
constant light strip Of that metal ono inch long
lever by which its expansion might be maintained,
would yield. at 1900 degrees. u light suitable for
most purposes An ingenious artist would have
very little difficulty, by taking advantage of the
ments of tho lever. in making scf-acting. sppa-
ratus in which tho platinum should be maintained
change taking place in the voltaic current"
'Tncre, said the Professor "that, as you see, Is
clipped from the american Journal Of Art and Science
for February ~. ls47. Tho ingenious artist was q
long time in coming. but he has arrived in the per-
son of Edison. In addition TO the platinum strips
Colt gave me Breguet thermometer, which used
for many years, but 1t was destroyed in 1866, when
the Medical College was burned. 1t was the most
delicate instrument of the kind ever saw 1t
sisted of strip of platinum and strip OF silver
soldered together by strip Of gold. The whole
thing only foot long and one-twentieth an
inch In thickness. 1t was delicate that IL you
brcathcd against IL it would instantly register o."
rE PHoepuoREscENT ELEMENT.
''It ia said in the newspapers Professor, that Mr..
Edison Is at present working, not merely upon the
incandescent pan but that thore is aphosphorescent
element In his invention"
Professor Draper smiled incredulously. Il have
no faith whatever" said he. in anything of that
kind Phosphoresccnce IL altogether too transient
and feeble 70 be of any practical utility means Of
producing light 1 will show you the phospho-
of of the best substances that s known
for that purpose and you can Judge for yourself
whether 1t would be likely to afford practicable