The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1902-01-22
COOPER HEwITTs NEW LIGHT
Mercury Gas Instead of Film to Con-
duct Electricity.
New York Sum

New York SUM-
over the entrance to the house of the
| American Society of Mechanical Engin-
| GERS at i West Thlrty-first street. there
| hung last night what looked like a col
/ umn of cold, blue-white light. about four
| inches Ia diameter and about four feet
/ nigh. 1t gave a brilliant Illumination to
/ the street for nearly half a block. In
| side the house the auditorium was lighted
! by flVe similar lights but OF lesser diam
eter, and the light of the hall was almost
IKE sunlight Beneath these lights,
when looked ike big candles, sat several
/ hundred members OF the American Insti-
| tute of Electrical Engineers TO listen to
| the reading Of paper on Electric Gas
Lamps and Gas Electrical Resistance
| Phenomena by the young inventor of
the lamps, Peter Cooper Hewitt. son OF
the Hon. Abram s. Hewitt
some six OF eight years ago Mr.. Hew-
lit came to the conclusion that better
ana cheaper light than that supplied by
either the arc or incandescent lamps
could be obtained by the use of gas
as the conductor instead of the film used
IN the Incandescent lamps. He began eX-
perlmentins IN his laboratory in the tower
OF Madison Square Garden, with the re-
suit that ne has obtained such q light
and except for the perfection of a few
details is ready TO put it on the market.
. 9 @
Mr. Hewitts lamp consists simply OF
a glass tube, with a bulb at one end, into
which he introduces the gas gens rated
from mercury. The tubes when filled.
are connected with the ordinary electric
power in any building and the current
turned on The gas acts az the conduct
or and as soon AS the switch is turned
the tube is flooded with light Four Of
these tubes were placed at regular inter
walls around the gallery of the auditOri-
UNI last night and one was hung from the
ceiling. The incandescent lights were also
turned on and the light from these looked
IKE jets of uncertain yellow flame. as
compared with the light in MIR. Hewitt's
lamps.
The lamps attached TO the gallery gave
light equal to that of about 200 candles.
while the one over thhe entrance to the
mouse seemed to have about twice as
mucn power; Mr Hewitt says that he.
can produce his light at about One-eighth
the cost of the incandescent lamps and
about One-third the cost of arc lamps
and of gas lamps.
The lamps were used last night chiefly
10 Illustrate Mr.. HeWitts paper and to
show TO the members of the institute
what progress he had made in his ex-
periments. In the course of his paper
he said:
q 81 %
The mercury gas lamps exhibited to-
night are operated on the STANDARD Edison
llo-VOt direct current circuit installed in
this building; lamps of this class con-
sumo amounts of current varying from
p-4ts " cAh slAlltiCS. ana the efficiency Is
approximately one-half watt per spherical
candle power. Under better conditions
as high an efficiency as one-fourth watt
per spherical candle power has been OBJ
ate measurements.
Il have made lamps with diameter of
bore less than On-eighth of an inch and
as large as three inches. and from less
than three inches I'm length up to over
ten feet, giving from less than ten can
dies up TO fully 5000. Lamps of very
small bOres give more trouble in manu-
facture and operation than those of mod
crate size Lamps of innumerable shapes
and dimensions have been constructed
ana great variation of candle power for
various dlameters obtained. There an
pears no reason why lamps may not be
MADE OF any size required and of any de-
sired candie-pOwer per inch within wide
limits, the only limitation appearing be-
ing that imposed by sOftening of the
glass when too many candle power per
inch are produced. The general rules es-
tabllsned regarding their operation hold
s0od IN so Tar as examined. and il is pos
sible 70 predetermine with almost absO-
lute eXactness the voltage. current con-
sumption and candle power Of a lamp
when the manufacture is perfect.
The light produced by pure mercurs
gas comprises orange-yellow. lemOn-vel-
low, green, blue, blue-Violet and violet.
q although all shades of these coIors
aHdy not be present, their absence would
the absence OF the red. For some pur-
poses the lack Of red in the spectrum is
Objectionable, but for many uses il is a
positive advantage.
For shop work. draughting, reading
and other work where the eve is called
upon for continued strain. the absence
OF red IS an advantage, for / have found
light without the red is much less ririnqr
TO the eye than with it. II is possible
10 transform some waves of this lighf
especially the yellow light. into red Ii9bf
ana mus III a measure to overcome this
defect where required for general indoor
illumination A moderate amount of or
binary incandescent light interspersed
with the mercury gas electric light serves
TO supply the deficiency. and the mixture
may he made most satisfactory For or
binary street lighting purposes the Iner-
curry light IS available even without the
REQ. and il should be noticed that this
hght has very great penetrating DOVER
and seems TO be effective through great
err distances than an equivalent amount
OF measured candle power from the ordi-
nary incandescent lamp. This NAV be due
70 the TACT that the waves of the red
hSnt are less penetrating than those
waves which are present in the mercury
light and hence the least valuable nor
ton OF the spectrum having such illunin-
atlng etieets Is omitted and the energy is
practically expended in the more useful
portions of the spectrum
When II Is considered that this light
when obtained with mercury gas. has an
efficiency at least eight times rs Great
as that obtained by the ordinary mean
descent lamp. II will be appreciated that
It has its use in places where lack of me
REQ IS not important, for the economy OF
Operation VIII much more man cor,nan
safe for the somewhat unnatural ,oio-
given TO Illuminated Objectsn
The general subject discussed AT the
meeting was Methods of Inumination /
ana nlts Of Light. and besides Mr.. I
Hewitt's paper others We're read bv T-
9 iaytoH Halsey Sharp DR. I.onis Rel
w A. Ryan aud John W Howell.