130
lamps are only half as good. The minimum total cost is doubled, but the maximum
Lamps 50 cts. each—Life 600 hrs. at 3 Watts per Candle.
Current costs 10 cts. per ㏋. per hour.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a5/Incandescent_Electric_Lighting_-_Efficiency_-_Fig_9.png/400px-Incandescent_Electric_Lighting_-_Efficiency_-_Fig_9.png)
Fig. 9.
efficiency is the same as in the previous case.
In this case, Fig. 10, the current costs one-half of that assumed in the previous