The evening times. [volume] (Washington, D.C.) 1895-1902, 1898-01-06
EQUAL TO Fl E SUNLIGHT.
NikoIa Tesla Takes Photographs
with the vacuum Tube.

Nikola Tesla, the well-known electri-
clan, announces an important diseoV-
cry in the ELECTRICAL Review. He says
that he hasI perfected vacuum tubes
OF such high illuminating power that
they may be- us9d in lighthouses. and
that they will enable the Photographer
to work by night as well as by day.
He even suggests. that by means or
this light the painter may be able to
distinguish colors as wei at night as
he can by the clear soft light of day.
The result which Mr.. Tesla has at
tanned represents several years or pa
tient experimenting. His work was
somewhat retarded by the burning of
his laboratory in 1885, He is not ready
yet to describe his invention in detail.
He promises to do SO soon. He always
| speaks in a conservative way OF his
discoveries.
The result which Mr. Tesla has at
| tanned have been achieved by the use
| of his vacuum tubes and his oscillator.
! The light which he is able to produce
| by this means is as bright as that OF
| the MONDAY sun. By its use every
| line of the object photographed may
| be made to stand out clearly and dis
| tinctly.
Mr.. Tesla has taken several photo
| graphs by this light, which are re-
produced in the Electrical review.
| Half tone engraving cannot begun u
! do Justice to the extreme clearDess ana
| deljcacy of these photographs. 1t is
| possible to give only suggestion OF
/ the clearness of the original in pict-
/ ure such as is used for the purpose
| of newspaper Illustration. The original
photograph was made under the light
| of single vacuum tube at distance
of five feet, with an exposure OF hNe
| seconds.
Every wrinkle in the face OF the man
! IS clearly shown. The hairs of the
| beard and the eyelashes are distinct.
| The effect is almost startling. The lace
| seems to stand cut from the paper.
| This photograph was taken, too. With
| ont the discomfort 20 the subject which
| attends the use OF The liashllght
Another development of Mr.. Tesia
vacuum tube which viii prove OF IN
| calculable value concerns lighthouses.
II is well known that il is difficult to
secure a light which will penetrate
fog. IL is believed that light from the
vacuum tube will eventually De used
for this purpose 1t is likely that prac-
tical experiments will soon be made in
| some lighthouse on this coast for the
| purpose OF demonstrating the practica-
| biIity of Mr. Tesla's invention.
by producing tubes of much great
err candle power" says Mr.. Tesla in
n letter to the editor of the Electrical
Review, speaking of progress in cleo
, trio lighting "a notable improvement
in this respect was effected. and this
advance prompted me to further efforts
in this direction, which finally result
ted in the production of tube OF ar
illuminating power equal TO that oil
hundreds, and even thousands, OF or
binary vacuum tubes. What Is more
believe that / am far from having
attained the limit in the amount OF
light producible. and believe that thi:
method of illumination will be eventu-
ally employed fon lighthouse purposes
This probably will be considered the
oldest and most unlocked for develop
| ment OF the vacuum tube.
Mr.. Tesla says in his letter that M
| finds that from an ordinary vacuum
tube, not much greater in volume thar
| an ordinary incandescent lamp, aoou
the same amount of light is produced
as from the Iincfindescent lamp with
| out any overheating.