169 
‘ARTIFICIAL ILLUMINATION. 
candle power, sufficient for an ordinary-sized room, by various systems, 
and taking into account all such incidental expenses as are due to 
repairs of lamps, chimneys, renewals of mantles, etc. 
Domustic LigHtina. 
Annual Cost of maintaining a light of about 48 candle power— 
2000 hours’ burning. Results of tests under practical conditions. 
Gas,,. ‘“Argand’’| Three 16 candle Lamps | 30,000 cubic ft. of 
consuming each 5ft. of gas at 2/6 per 
gas per hour. 1000 cubic feet 75/—) | 
Renewal of chim- | 78/— 
neys 3/- 
5) «-  Wenham’’) One Small “* Wenham” | 14,000 cubic ft. of 
Regenerating) consuming 7 ft. per gas . SET | 40/- 
hour. Repair of Lamp, &e. 5/- 3S | 
» ‘“Albo-Carbon”| Two No. 2 “Bray” Burn- | 14,000 cubic ft. of | 
ers consuming each 3} GOS coe .85/-) | 
ft. perhour, carburetted balbs. of Naphtha- | 48/— 
with Naphthaline. line at 3d. .. 18/- 
5,‘ Welsbach’’?) One new ‘“C” Lamp, ee cubic feet of 
Incandescent} giving 12 candle power as . . 20/—) | 
per cubic foot. neceeelse Mantles, 
three at 1/3 3/9 - 25/8 
Renewal of chim- | | 
neys 1/6) | 
| 
PETROLEUM. One 48 candle “‘ Vulean”’ | Oil consumed at 6d 
Large Lamp} Lamp burning 1 gallon per galion . 85/9 
in 28 hours. eee Wicks, ae | 38/- 
&e. . Sr BB) 
», Small Lamps| Four 12 candle Lamps | Oil consumed... 47/7 | 
each burning 1 gallon | Chimneys, Wicks, 50/- 
in 84 hours. ISS Be 2/5 
ELECTRIC Three 16 candle Lamps | Cost of Current at 
Incandescent} absorbing each 64 6d. per Board of | 
“ Watts.” Trade unit (1000 
Watt-hours) ...192/- 
Lamp renewals, 8 204/ 
at 1/6 .. 12/- 
Note.—The figures above apply to the use of the various illuminants 
under ordinary household conditions. 
course, give better results. 
Careful laboratory tests, of 
You notice that while the Argand gas burners would cost 78s. a 
year, the “‘ Wenham ” lamp would be cheaper at 40s., and “ 
bon” burners at 48s., while the “ Welsbach” 
albo-car- 
-Iincandescent would 
supply us with the same light for 25s. 8d. A large “ Vulcan” petro- 
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