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Special attention has been given to ventilation and an entirely novel system has been introduced which,
while providing a large radiating surface, allows a current of air to be drawn continuously over the lamp. A sectional plan
of the ventilating device is given in Fig. 4, the arrows showing the course of the air currents.
Another noteworthy feature of the "City" lantern is the provision of a simple yet substantial focussing
device. After screwing the lamp into the holder it is gently pushed to the correct focal position where it is firmly
held in place by the rachet. This device is particularly useful where adjustments have to be made by linesmen at the
top of ladders.
Clear flint globes are supplied unless otherwise stated. Opalescent globes can be provided to order at a slightly
increased price.
The glasses are wired to minimise the risk of accident through breakage whilst suspended. Safety chains are also
provided so that the globes can be lowered for cleaning.
A special U-section rubber gasket forms a watertight joint between the rim of the glass and the lantern and guards the rim
against breakage.
Two standard types have been produced, one with spun steel reflector which is recommended for general use and the other having
a cast iron reflector for use in extremely exposed positions of where the extra weight would be adventageous.
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