The daily telegram. [volume] (Clarksburg, W. Va.) 1901-1926, 1915-02-05

$50 E4tf tAAO ReSAAtk9 We - "
the fewer columns between the
'panes: the higher in the wan and
the nearer the coiling. the greater
amount Of light It will supply. The
kind Of glass Is important. Clear
plate glass is best. More illumina-
ltion is gained from ribbed glass be-
cause light rays are refracted in the
uneven surface OF the glass and In
stead Of falling directly to the floor
are directed horizontally into the
room. thus Illuminating larger area
than plain glass. Coloring OF any
kind lowers the lighting property.
Window glass should be kept absc-
Fiutely clean A German inspector
estimates that thirty per cent OIL
lighting power is lost In glass COW
erred with dust and seventy-two peri
cent through glass which Is yeryl
dirty. d.
When the daylight Is insufficient,
or the factory is operated at night.
artificial lighting is required. Arti-I
fetal light has the advantage of
being more easily regulated than
daylight and thus is more uniformI
in its results. II properly regulated.
1T need not be trying to the eyes. The|
three artificial lighting mediums now
used In industrial plants are acetl-
lene gas, illuminating gas and cleo
Itricity. Except for a few tenement
workshops. no industrial plants are|
lighted now by kerosene lamps.
Acetylene gas is made from calcium
|carbides, in special generators out
lside Of the establishment. It ISL
|piped through the building like illu-
minating gas and Is used in rural
districts. where city gas and electric
lity are not obtainable. 1t produces
la bright, clear light resembling day
light, and Is generally regarded as
being comparatively easy on the eyes.
illuminating gas Is used satisfactorily
in many large factories. Open flames
are being rapidly discontinued as In
efficient and dangerous. Incandes-
cent mattel burners in a variety Of
styles are replacing them for eco-
nomic as well as hygienic reasons.
The best mattel burners produce a
shaded in some way.
Electricity is used in arc lamps,
both of the fame carbon and the
older enclosed types. Incandescent
electric lights are used more FREE
lquently than either of these. as they
produce less glare. The old form
with carbon filaments is being re-
placed with the metal fllament tung-
lsten burners, which produce high
Hight intensity at about a third of
1.-THE cost of the older style.
Certain industries make specific
Hight requirements. The mercury
vapor lamp which produces a blue
lgreen light is considered essential in
sugar refineries to detect Impurities
lin refined white sugar. It is claimed
lthat this light is Injurious to the
Ieyes, and ocular inspection OF the
work IN a large refinery recently re-
'ivea1ed a number Of cases of conjunc-
'Itivitus. Hundreds Of girls employed
lin film factories are compelled to
sIwork for hours in finishing films UNI
Ider AIRED light. Acareful examina-
ltion failed to indicate any injurious
EFFECT of the red light either upon
their vision or their general health.
il The question as to what consti-
flutes adequate and proper lighting is
mot yet fully answered. as experts
lare continually experimenting upon
! the subject. Definite standards do
mot exist. and the present defective
lighting systems are chiefly due to
this lack of Standardization. Illu-
! n1ination is usually measured by pho
tometers and the unit of illumination
is expressed by the term candle
foot This is defined as the direct
!, illumination given by a standard
candle one foot from. the object 10
be illuminated. Roughly speaking. a
foot candle represents the minimum
illumination by which It is possible
\ to read small print for continuous
! period without fatigue. On cloudy
days, the. daylight indoors varies
-Ifrom to 4 4 Q foot candles. On sun.
: shiny days 1t ranges from 20 to :
foot candles. In Germany, one foo,
candle is regarded as sufficient t.
: read by. and from /. 5 to 5 foot can
ldles are required for fine work in
factories, while for specified indus
tries. including embroidery, printing
'land knitting. an intensity Of not less
] than ] 1-2 foot cables must be sup
,lplied.
The lighting OF an Industrial plant
! must fulfill the two objects Of pro-
Ividing the light for work, and pro-
Testing the worker and the public
& from accident. Several forms oil
lighting may be required for doing
this properly. General lighting
gives a uniform illumination through
out the room, but localized lighting
throws special illumination upon the
specific point. In number OF up
lto-date clothing factories small
electric lamp. rejecting directly upon
the point of the needle, is supplied to
each sewing machine. in addition to
the excellent general lighting sys..
lem In the room. Miners suffer great
~ from having to strain their eyes
in order to see the points d their
picks. In many cases, the old-fash-
Toned miners lamp could not be used
on account Of the fire risk. The Blu
reau Of Mines is now making exhaus-
tive tests for determining the safety
of portable electric lamp for
miners. which has lately been intro
lduced. "a