224 The N.Z. Journal of Science and Technology. [July 
them from an ordinary lamp-holder attached to a cord pendant. They 
should always be connected to a plug having sufficient capacity to carry 
the current, and not from a lamp-holder which, unless specially designed, 
will not carry the current without rapidly overheating. It would be better 
if the retailer always made a point of advising his customer of the hazard 
run in operating off a lamp-holder, but I frequently find that he will sell 
and attach an adapter to the apparatus so that the customer can use it 
from any lighting-point in the house. A retailer has no moral right to 
keep silent on this point when he knows, or ought to know, what the hazard 
is, while in nine cases out of ten his customer does not. Perhaps he will 
not run the risk of losing a sale by advising that it would be necessary to 
install a plug if there was not one installed already. 
Radiators which depend on resistance wires for giving heat are extremely 
hazardous unless the wires are so protected that nothing inflammable can 
come in contact with them. Radiators of this type should always have 
at least one glow-lamp in circuit to show that the current is on, which 
should be controlled by the switch controlling the radiator, and fixed on 
the wall. 
Electric ranges and small cookers, which are rapidly becoming more 
popular, require special care when being installed. All portable apparatus 
carries not only a possible fire hazard, but the possibility of shock, and this 
is particularly so in the case of the electric range. It is subjected to great 
heat, the liability of spilt grease, and the “ boil-over ” of different food¬ 
stuffs. The range is installed in the kitchen, and the wiring would probably 
be subjected to more rough usage there than anywhere else, due to the 
constant cleaning and washing down. If the wiring cannot be brought 
in conduit right up to the range it should be brought from the plug 
in flexible steel tubing, and the tubing, range, and all switch-covers 
permanently earthed. Efficient earthing is of the greatest importance 
to prevent any danger of shock, which may lead to serious results on a 
230-volt supply. 
Electrically heated pads, foot-warmers, blankets, and cloths, as they 
have appeared on the market, cannot be considered as satisfactory when 
put into practical service. Such devices when tested in the open and freely 
exposed to the air might operate in an apparently safe manner, but it can 
be readily understood that when they are covered with a mass of heat- 
insulating material the temperature may rise sufficiently to ignite the 
inflammable material before the heat is dissipated. Usually the device is 
provided with a thermostat, or automatic cut-out, to operate at a pre¬ 
determined temperature, but they are quite liable to sticking and arcing 
at the contacts, while the adjustment may be changed, increasing the 
temperature at which the circuit will open. In any case, they will not 
stand for any length of time the rough usage to which they are usually 
subjected. 
The ordinary cord flexible as generally used for drop pendants should 
not be used for any portable device. Dragging the wires over the floor, 
allowing them to kink, treading or placing heavy articles on them causes 
the insulation to deteriorate rapidly, introducing the possible hazard due 
to earthing or short circuit. The flexible should be covered either with 
an armouring of fine-woven steel wires or a sheathing of tough rubber com¬ 
pound known as “ cab-tire sheathing.” The flexible should have some sort 
of grip at each end to prevent the wires being dragged out of the terminals, 
which is another possible hazard. 
