Evening star., 1897-03-13

" hite light in sufficient quantity to ''ilu-
inmate a small room" Professor Ebert,
the well-known German scientist. has
made measurements which show that
single horse power of electric energy would
he sufficient 10 operate 46,W0.OoO Puluj
lamps.
This simply means that we are on the
verge OF a vast discovery in electric science.
Taken in connection with a recent state
ment of Prof. Oliver j. Lodge, can we'll
believe that the lighting system of the fu-
ture will be little short of marvellous as far
as the generation of the light Is concerned.
Professor Lodge. who Is the head of the
department of experimental physics in Uni
versity College. Liverpool says that "if
mechanical energy can be converted entire
" INTO light alone. one man turning the
crank of a suitable machine could generate
enough light for whole city Puui
claims that his lamp fulfills this condition
ana Is working hard to bring it down to a
practical basis If he does So he will have
perfected the most economic lighting sys-
TEN in the world.
The Light of the Future
These statements may be said to recount
the initial attempts to produce what is
popularity known as "the light of the
future IL is the dream of scientists at
the present time to produce light without
heat That is. TO perfect system in which
every bit of the producing energy will be
turned into light. AS our electric-lighting
system now exists. only from 1 to 3 per
cent of lUp per cent is expended In light.
The rest of the energy passes off in the
form of heat 1t Is this immense waste of
energy which makes Ii necessary for us to
employ steam engines. dynamos and ex-
pense creating apparatus of all kinds in
producing what Is. after all. but a mere
residue of Illumination In short. to pro-
duce = or per cent of illumination We are
compelled to throw away 81 or Ss per cent
of heat Scientists. then. are striving to
this immense waste and this. prac-
tically. is what Prof Lodge means by say
ing that il IL becomes possible to convert
mechanical energy into light alone. whole
city might be lighted by the simple turning
OF crank shaft
What the New Lamp is Like.
Puluts lamp is not operated by dynamos
or storage batteries. 1t operates with a
lighted by means of induction coil or a
glass plate electric machine. The static
electricity thus produced is the same in
every respect as lightning. 1t is atmos-
pheric and its voltage. electro-motive
force is so great that il will readily pass
through the air. 1t need. therefore. sur
prise no one to know that the lamp of
PuluJ can be operated even through only one
terminal OF the induction coil tthe negative
pole for instance, Is connected 10 1t. The
lamp itself Ia shaped very much the same
a. an ordinary Edison incandeScent lamp,
except that the wires iea0fnS into tne lamp
do not extend up the neck from a socket
They extend directly through the side of
the bulb. They are made of aluminium
The negative pole. cathode. ends In a
small refiector-shaped disc. Hanging from
the point apex of the lamp globe is a
small square sheet of mica The piece of
mica faces the reflector disc, negative
pole. and is painted with sulphde of cal
cium. extremely phosphorescent sub
stance. When the negative pole of the
lamp is connected with an induction coil
the current is. as IL were. concentrated by
tbs. little disc in the lamp. and a constant
stream of radiant electric matter flows
from IL and bombards the painted sheet of
mica. which Immediately giows with an
intensely brilliant phosphorescent light
This is PuluJs lamp as IL exists today.
The heat evolved from il is infini;esimal
in quantity Nearly all of the energy put
into il is converted into light. II Is there
fore the nearest possible approach 10 colo
light that has vet been made. But IL IS
not in its present stage available for gen
eral lighting purposes. Puluj is expert
menting with a view TO arriving at solu-
ton of the obstacle. IL is his belief that
the general advancement of lighting and
the solution OF the problem of making
light entirely without heat will be found
by chemical means. He is carrying on a
series oi Investigations to the end of pro-
ducing a chemical lighting system. Not
the production of light through the con-
sumption OF chemicals but as far as can
he learned, the chemical conversion of the
ether INTO llSht. Ii is not easy 10 imagine
now this Is TO be done. but such is the
statement Puluj. IL the fates smile on his
experiments. will some day base an ether
system of light production on his little
lamp He is seeking 10 devise some method
Tor csciilatins the ether as to produce
light In case Of success his lamp would
become an object of great interest Great
obstacles lie in the way and for the sake
OF the uninitiated a little explanation may
be nece< sary.
What Light is.
The man who maintains that 1.-THE sun
do move" will declare that 1t is also the
source OF light But the modern scientist,
while acquiescing in the fact, will add that
light Is condition Of the surrounding