LIGHTING 



43i 



give the watts. For instance, a no- volt lamp consumes Ko 

 of an ampere. It is therefore a 3 3 -watt lamp. Lamps are 

 now rated according to the wattage rather than by the candle 

 power. Although in the medium-sized lamps very nearly 

 one candle power will be produced for each watt consumed, 



To sr>o/br 

 Co/wecf/on cox 



To /^-f/oor 



To frou/ia- 

 f/oor //pAfs 



L/GHT 



Plant 



'4 



\ 



3/lPM 



•ggstom&BB 



ruse- 



To Bastmen^ 



J 



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v j7h /if.f/oA 

 :k* LifJifsJ 



Tol^stf/. 

 1/fAA 



A/Oi/JE 



After University of Minnesota 



Fig. 328. Suggestions for wiring house and barn. Fuse-boxes and 

 switches at each building are shown. 



in the smaller lamps — that is, in the low-voltage small lamps 

 — the amperage is one-half higher than in the larger lamps. 

 A thousand watts are known as 1 kilowatt; 746 watts equal 

 1 horse power. Therefore a 1 -horse-power engine would 

 turn a generator which would give us 746 watts, minus 5 

 or 10 per cent loss by heat and friction in the machine. 



Lamp hours. ' In the planning of an electric lighting sys- 

 tem the number of lamp hours which will be required must 



