The N.Z. Journal of Science and Technology. 
264 
[Jan. 
expensive than with an ordinary kettle. The results obtained were as 
follows:— 
Ring Burner. 
Top of Ordinary Gas-stove. 
Bars on. 
Bars removed. 
Copper kettle .. 
“ Magic ” kettle 
Per Cen\ 
50 
Per Cent. 
32 
Per Cent. 
53 
70 
54 
75 
The last two columns refer to the iron bars stretched across the top of 
the stove for mechanical support of the kettle, &c. The figures in the last 
column were obtained by removing these bars from above the burner and 
providing suitable insulated support for the kettle. The results show that 
in the cases of the two stoves experimented on these bars dispose, by 
conduction and radiation, of 20 per cent, of the heating-value of the 
gas, and that without them the kettle would boil in over 30 per cent, 
less time, with corresponding economy of gas. It must be admitted 
that both the stoves tried were 
bad in this respect, one having- 
bars in. by Jin. and 1#J in. 
apart. It can be calculated that 
the annual saving in Wellington 
by attention to this part of 
design would be of the order of 
£15,000. 
Experiments were also made 
with a special kitchen califont 
illustrated in fig. 4. With average 
rates of flow the efficiency of the 
device was about 58 per cent., 
showing that such an arrangement 
is well worth installing in an 
average household from economical 
considerations of both fuel and 
labour. 
With regard to electrical 
heating for kitchen use, heating- Fig. 4.—Kitchen califont. 
elements of high current - con¬ 
sumption are required both for convenience and full efficiency. On 
the other hand, tests showed that an efficiency of 75 per cent, 
could be obtained with a grill heater, and 90 per cent, with immersion 
heaters. 
Experiments were made also using an ordinary “ Perfection ” oil-stove, 
as illustrated in fig. 3. The consumption of kerosene by the stove was 
observed, and the heat given to kettles measured. In the case of a 
“ Perfection ” stove the £ ' Magic ” kettle mentioned above gave an efficiency 
