The review. [volume] (High Point, N.C.) 1908-19??, 1914-04-30
COST OF ELECTRIC LIGHT
Facts and Figures About Incandescent
Lamps, Explaining the Elec-
trio Light Bill.
(Selected.)

trio Light Bill.
(Selected.)
When one is able to figure out the
exact cost of an incandescent lamp
for one hour then it is an easy matter
to understand the regular monthly
electric light bill. In this way you
can figure out the Individual lamps
which are costing the most and Ger
rect any errors in the lighting sys-
tenn.
You pay for electricity by the kiio-
watt. A kilowatt is merely thous-
and watts. Watts is an arbitrary fig
ure in electricity meaning the same as
"horse power" in mechanics. Every
one understands what ten horse pow
er means. 1t means that a motor, or
engine, will produce energy equal to
the work of ten horses. Now TAG watts
are equal to one horse power. There
fore one watt is equal to 1-746 of
horse power. A thousand watts, or
one kilowatt, is equal to one and one
third horse power. If your electric
light bill says you have consumed 80
kilowatts it means that you have used
40 horse power of electricity during
the, month. If the monthly rate is 10
cents kilowatt you will pay for this
power So, which is very little indeed
for the use of $40 horses"
Assuming that tungsten lamps are
installed, what will they cost per
lamp? Look on the bulb of the lamp.
You will find there little paster Civ
ing the number of "watts" required
by the lamp. Let us take the smallest
lamp first. It is rated at "ten watts"
and will give eight candle-power of
light. If the rate per kilowatt for one
hour or 1000 watts, then it will cost
O.0001 of p cent for one watt and 0.001
of cent for ten watts for one hour.
At this rate the ten watt lamp could
be left burning for 100 hours, or near
ly four days and hat, before it would
burn up ten cents worth of electric
ity.
The next size is the Is watt lamp
which gives about ten candle power
of light. This lamp will consume Is
cents worth of electricity in. 100
hours of continuous burning at the ten
cent rate. In one thour it will con-
sumo 0.O015 cents worth of electri-
city. In 10 hours of continuance ser
vice it will have burned up only 0.015
Or a cent and half's worth of current
The next size lamp is the Is watt, or
twenty candle power lamp. This lamp
will burn for 40 hours before consum-
ing kilowatt, Or ten cents worth Of
current.
The largest practical sized lamp for
use in the home is the, 40 watt lamp.
This lamp should be used only where
large amount of light is necessary
for short intervals. 1t will burn con-
tinuousy for rs hours for kilowatt
Of current.
Now that we know exactly what
each lamp costs per hour care should
be taken in the placing and distribu-
ton of the lamps to see that the
smaller size are used where the long
est light service is required. On the
porch, in the halls, the bathroom, etc.
Where only a small amount of light
is needed but where the lamps. are
allowed to operate for hours, the small
sized-ten watt lamp should be used,
as one of these lamps can be used for
hundred hours continuously for a
cost of but ten cents. In the bed
rooms, den, for the reading table,
etc., where a little more light is neces-
sary, the Is and rs watt lamps should
be placed. For the kitchen, dining
room and living room, where maxi
mum amount of light is required, but
for shorter hours of service, the 10
watt lamps are entirely suitable, or
two of the Is watt amps may be used
to give better distribution of light.
1t is always better, whenever posi-
BILE, to use two or more of the smaller
lamps about the room instead of one
large lamp, in order to secure a good
distribution of light and avoid the
glare Of single high-candle power
lamp.
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