The morning news. [volume] (Savannah, Ga.) 1887-1900, 1899-04-17
NIK0LA TESLA'S DAYLIGHT.
SEVERAL NEW York BUSINESS
HOUSES.


What Artificial Daylight Really Is
and How Ii Differs From Incan-
descent LiEhting-NHay Have
Bulb Yard LOng-Never Grows
Hot-immense saving of EIectrici-
ty-TesIa's New DynnmO-HOw
Tesla Photographed His Hand by
Artificial Daylight.
New York April 1.-THE promise made
by Nikola Tesla TO the world some two
years ago that he would soon give it a
means of lighting It's homes. its Offices
and its streets at night time by artificial
daylight" has been fulfilled The inven-
ton has been entirely completed for sew
eral weeks. a day or two ago the au-
thoritatiye announcement was made that
contracts have already been signed with
several New York business houses 90
equip their business places with the new
hght at once. The promoters of the COM
pony which is pushing the new invention
are so certain of its great practical util-
ity that they predict that il must soon
supplant the arc lamp.
cy currents" is what Tesla himself calls
il. The name. though clumsy is sufii-
GENTLY descriptive. The essential parts
are a vacuum tube, and special current
of high frequency, produced by a special
dynamo, of Tesla's invention THE
tubes MIR. Tesla explains, have had all
the air pumped out. but. of course, are
fun of ether. The passage of this special
current sets the ether in motion, forming
light waves. The light differs from arc
illumination In that II has no particular
center The whole tube COWS and sheds
a radiance like daylight all around"
The tubes, of course, are sealed tight
al both ends. A wire Is made fast 10 one
end. but there is no wire inside. The
tubes at present in use are about a foot
long. For special purposes, such as stu
do Illumination, street lighting and so on,
they can be made any size up 20 a yard.
The glory and the beauty of them Is that
their light goes all over the pace to be
illumlned-is as strong in the corners of a
room, as directly under the tube Hence
the truth of its name artificial daylight.
A lighted tube in a room has exactly the
effect of daylight flooding the windows.
notwithstanding the tube itself Is NOT
trying 10 the eyes You may look steadily
at it, with no evil effects whatever.
In incandescent lighting 81 per cent of
the electric current goes to making che
hlament hot, leaving but 3 per cent. for
illumination. And this brings us to a sec
Qua long advantage of the vacuum tube.
1t never grows hot. You may touch the
glass an hour after the light Is turned On
and find it as cool as when first lighted
An electric bulb in like case is hot enough
TO scorch, not TO mention giving head
aches to the luckiess mortals who hap
pen to sit directly underneath or beside 1t.
Ihe tubes can be attached to the electric
Hight fixtures in common use. but cannot
be iAumined by the ordinary current. Or
rather they can be made to glow with It.
but the process is too costly. That was one
thing that made the wise men doubtful a.
the beginning few of them thought
Tesla might probably perfect his light pro-
cess, but were firm in the belief that il
would remain too costly for commercial
use.
Teslas new dynamo has changed all
that. Contracts now signed insure that sew
eral important structures IN New York city
viii be equipped with the new light There
can be no doubt that Ii will rapidly sup
plant other methods of illumination as
soon as moneyed men build and operate
high frequency current stations. The first
cost of wires, tubes, etc, Is about the
tubes have the very great virtue of not
burning out after the manner of incandes-
cent globes or carbon pencils, hence the
cost OF operation will be very much less
When 1t comes to use there is simply no
comparison possible. II is just the same
as having a day twenty-four hours long.
Everywhere, for every purpose, artificial
daylight equals the real thing. Witness
this picture of the inventors hand. The
photograph for 1t was made at midnight in
his laboratory, with a two-second expos
ure. II was not only taken, but printed by
the artificial daylight yet 1t will be seen
that IL shows clearly the lines OF the
palm and the texture of cuff and sleeve.
Nothing remains now but to equip the
world with proper wires. dynamos, and so
on. Men with money know a good thing
when they see it, even without artificial
daylight, so It Is very likely that In
matter of twelve months there will be
practically no night in any considerable
city Of the world.
Chauncey Montgomery McGovern.