use. These are the ortiinarj^ carbon, the metallized earlion
or "Gem/* and the tungsten lamp. Nearly all of the last
kind sold in this country hear the trade name '* Mazda.**
All three kind8 are commonly marked with the number of watt^
(power) they take when used at the number of volts (electiieal
pressure) also marked on the lamp. When electricity is paid
for at a certain rate a kilowatt Iiour, the cost of current for any
lamp is easily calculated. The kilowatt hour is 1000 watt hours,
and the number of watt hours used by any electrical device is
simply the watts tinier the number of hours burned. For ex-
ample, a .30-watt lamp in twenty houi-s use^s I, (MM) watt hours
or 1 kilowatt hour; at 10 cents a kilowatt hour current for such J
• U. S. Bur. Standards, Circ. 55.
k
HEAT AND LIGHT
203
L
laoip eoHis one-half cent an hour. This is true of any 50-watt'
lamp without regard to the kind of filament it has. The amounts
of light produced hy ililTerent kinds of filaineiitB are, however,
decidedly different (Fijj;. 47), If the voltage nupphed in lower than
the lamps are intended for, the watts taken by the lamps are
reduced somewhat, but the light is reduced a great deal more.
The amount of hght obtained from a given amount of electric
Gem lamp
lannp
Carbon lamp
» 20 CAHPL6 POWER
Fio. 47,^ — Comp^son of amount of light given by diflereDt electric lamps.
For fompanf»tm a consumption of 50 watts m assumed, Although tungsten
lurnpfli tire not usually made in thm dxe. Fifty watts at 10 cents n kilo-
watt hour coatit U^ rent an hour, and givea 12 to 16 candled in a carbon lamp
and 40 to 45 in a tungsten lamp- Ml lamps give different candle-power at
different anjudicH, Each arrow in the figure ia proportional to th6 candle^
power in its direction.
energy depends, therefore, on the voltage. Under fsdr conditions
the amount of light and the corresponding cost for current (at
10 cents a kilowatt hour) would be alxjitt a^ follows:
TABLE Xll
Kiftd of lamp
Candles per waii
Cosi/ar 1,000
candle hours
in cents
Carbon *
0.25 too 33
About 0,40
0,80 to 1.00
30 to 40
Gem . , . . ,
25
Tungsten
10 to 12.5
I
I
Prom a 60-watt lamp, for examplej the c-andle power obtained^
is 15 to 20 for a carbon lamp, 24 for the Gem, and 56 for the
tungateu.
304
A MANUAL OF HOME-MAKING
Comparaiive cost of various common lights * (Fig. 48).
For the production of light a great variety of laraps are
available, aiiil in some kinds remarkable inprovements have
been oiade in the last few years. These improvements have
made it possible in many eases either to improve the hghting
of the home without iiiLTeasing the eost or to reduee the cost.
Kerosene Mame - - - ^
Kerosene Mantle— -1^
Gas Open flamc'--^
Gas Mantle -^
Carbon Electric --•■
'Gem* Electric - ^
Towten tkctrit-
a
k
^ io »9 £« «9 50 3» M
Cost ^1000 candle 'hour* In cenU,
Page 107
Presented as published in 1919. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
A modernized reading is not available for this page yet. You are seeing the original text.
use. These are the ortiinarj^ carbon, the metallized earlion
or "Gem/* and the tungsten lamp. Nearly all of the last
kind sold in this country hear the trade name '* Mazda.**
All three kind8 are commonly marked with the number of watt^
(power) they take when used at the number of volts (electiieal
pressure) also marked on the lamp. When electricity is paid
for at a certain rate a kilowatt Iiour, the cost of current for any
lamp is easily calculated. The kilowatt hour is 1000 watt hours,
and the number of watt hours used by any electrical device is
simply the watts tinier the number of hours burned. For ex-
ample, a .30-watt lamp in twenty houi-s use^s I, (MM) watt hours
or 1 kilowatt hour; at 10 cents a kilowatt hour current for such J
• U. S. Bur. Standards, Circ. 55.
k
HEAT AND LIGHT
203
L
laoip eoHis one-half cent an hour. This is true of any 50-watt'
lamp without regard to the kind of filament it has. The amounts
of light produced hy ililTerent kinds of filaineiitB are, however,
decidedly different (Fijj;. 47), If the voltage nupphed in lower than
the lamps are intended for, the watts taken by the lamps are
reduced somewhat, but the light is reduced a great deal more.
The amount of hght obtained from a given amount of electric
Gem lamp
lannp
Carbon lamp
» 20 CAHPL6 POWER
Fio. 47,^ — Comp^son of amount of light given by diflereDt electric lamps.
For fompanf»tm a consumption of 50 watts m assumed, Although tungsten
lurnpfli tire not usually made in thm dxe. Fifty watts at 10 cents n kilo-
watt hour coatit U^ rent an hour, and givea 12 to 16 candled in a carbon lamp
and 40 to 45 in a tungsten lamp- Ml lamps give different candle-power at
different anjudicH, Each arrow in the figure ia proportional to th6 candle^
power in its direction.
energy depends, therefore, on the voltage. Under fsdr conditions
the amount of light and the corresponding cost for current (at
10 cents a kilowatt hour) would be alxjitt a^ follows:
TABLE Xll
Kiftd of lamp
Candles per waii
Cosi/ar 1,000
candle hours
in cents
Carbon *
0.25 too 33
About 0,40
0,80 to 1.00
30 to 40
Gem . , . . ,
25
Tungsten
10 to 12.5
I
I
Prom a 60-watt lamp, for examplej the c-andle power obtained^
is 15 to 20 for a carbon lamp, 24 for the Gem, and 56 for the
tungateu.
304
A MANUAL OF HOME-MAKING
Comparaiive cost of various common lights * (Fig. 48).
For the production of light a great variety of laraps are
available, aiiil in some kinds remarkable inprovements have
been oiade in the last few years. These improvements have
made it possible in many eases either to improve the hghting
of the home without iiiLTeasing the eost or to reduee the cost.
Kerosene Mame - - - ^
Kerosene Mantle— -1^
Gas Open flamc'--^
Gas Mantle -^
Carbon Electric --•■
'Gem* Electric - ^
Towten tkctrit-
a
k
^ io »9 £« «9 50 3» M
Cost ^1000 candle 'hour* In cenU,