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pany have been persuaded to discontinue this process albeit the
process has not been of long duration or frequency.
Another instance of induced vibration in houses can be
quoted. In this case an electrically operated air compressor
working in the daytime only gave rise to vibration, evidence of
which could be seen and felt. Progressive improvements were
brought about by the provision of new foundations for the compressor
and the fitting of a suitable fly-wheel.
One source of noise nuisance to local residents was found to
arise from a factory in another borough. Somewhat ironically
most of the noise arose from dust extraction plants which had
been provided to prevent nuisances arising from dust, one to
intercept dust arising from a shot blasting process and the other
to trap metallic dust from a metal spraying process. Here again
this plant was sited at the rear of the factory but immediately
opposite dwellinghouses and was run on day and night shift work.
These dust extraction plants were constructed of metal, thus givng
rise to resonance and in the first instance attempts were made
to insert non-metallic jointing material in the ducts and to brace
those parts which were subject to vibration. Consideration was
given to lining the factory walls with noise absorbing material
to overcome reflection but this proposal was abandoned and a
baffle was constructed in front of the plant giving rise to the
noise. It was suggested to the Company that a baffle wall should
be constructed at the boundary fence of the factory premises
but owing to the fact that the boundary fence was on the bank
of a river it was considered that such a wall would not be
practicable. However, further investigations are proceeding at
the present time with a view of constructing a wall of much
lighter material than brickwork which would not be liable to displacement
by any movement in the river bank but would intercept
the noise.
Needless to say there has been collaboration between this
Borough and the Borough in whose district the factory is situate.
At one local factory a serious noise arose from the operation
of a wood chipping machine, even though the machine was below
ground level. The intensity of the noise can perhaps in some
measure be appreciated when it is realised that the machine was
capable of disintegrating long lengths of timber into small chips
in a matter of seconds. Although the Company were prepared
to replace this machine with a less noisy one it was not possible
to obtain one until quite recently. In the interim period large
storage hoppers were installed to hold a sufficient supply of chips
for use during the night shift and thus obviate the necessity for
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