Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1908-08-27
THE LATEST DEVELOP
MENT IN ARC LIGHTING
The Planning Arc Lamp which Gives
Three Times ~ Much LiGht for the
same Current.

1t is we'll known fact Sir Hum
phrey Davy discovered the brillia ncy Of
the electric arc while experimenting with
a powerful battery moro than a hundred
years ago The arc lamp. direct result
of this discovery. was the arst electric
| light, produced by the current arcing
over a gap between two carbon pencils.
! All the arc lamps so common in street
lighting are made on this principle.
| Several years ago German scientist
named Bremmer was experimenting with
| the electric arc, with the idea OF making
| II a better and more economical means Of
giving artificial light. He began by mix
Ing certain substances with the pure car
bon pencils. After months of careful
study and experiment he discovered that
ny impregnnting the carbon pencils with
salts of calcium or rare metallic earths
he was able TO produce luminous arc
that gave three times as much light as
the ordinary arc. This discovery resulted
In new type of arc lamp which gave a
veritable food Of light. equal to thou
sands OF candles.
A number Of the lamps were brought
to this country and American inventors
began studying the problems and expert
months in tho laboratories and the skilled
scientists. chemists and inventors Of the
General Electric company produced a
flaming are which rivalled, II not SUI
passed, in luminosity the foreign make
lamp.
Three kinds of flaming arc lamps are
produced: the yellow light. the white
light and the red light. The white light
cartoons produce a mellow white light but
are not very much more efficient than
the old open arc lamps. The red light
lamps are second on the list as illumin-
ants. and the light In reality Is a delicate
pink color The color Of the light pro-
duced by the yellow carbons Is deer
orange. remarkable for its softness effi-
cheney, penetrating qualities and adapta'
bility to the ordinary range OF vision
1t should be said In passing that there
Is a definite color range for the eye, Just
as there is a pitch range for the ear
Yellow causes the least strain on this
optic nerve because II comes In the mid
die of the spectrum and has wave
length that all eyes can easily apprehend
Some eyes are more sensitive to the Ions
wave lengths of red. while others are
equally as sensitive to the short wave
lengths of light blue,
The new flaming arc lamp differs bu
. slightly In general construction ana de-
sign from the ordinary enclosed arc lamp
/ The magnetic device which keeps th'
carbons always Mt an equal distance
apart, despite the continual wasting ava,
OF the carbon. PARTICLES Is nearly tn
! same
In the old lamps the carbon rods arr
made OF almost pure carbon and eight!
, per cent. Of the light is produced IRON
, the incandescent crater of the positiv
! carbon. while only II small percentage o
hight IL given by the arc!ng of the electrl
) current Across the gap between the wv
carbons. In the flaming arc the carbon
: are made of composition of carbon
} salts and minerals through the center o
which Is run thin strip Of metal 70
conductive purposes. These rods are plac
, ed In the lamp at an acute angle, IN
: lower ends almost touching The larg
; amount OF light is produced by a lum!
nous gas formed from the cunning com