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To estimate the amount of grit deposited about the district, trays were placed at different
points and the deposits collected daily and each month a table is presented to the Committee showing
the average collections per tray per day. Although this method is of value in indicating the variations
of the nuisance, this cannot be taken as true evidence, as the following factors must be considered in
drawing conclusions:—
(1) The humidity of the atmosphere, i.e., when low, particles of grit become more
widely diffused and when high, deposited in the immediate vicinity of the works.
(2) Strength and direction of wind, with a strong wind the particles are carried long
distances, whilst a downward wind, though strong, eddies the particles on to near-by property,
a " beam " wind localizes the deposit.
(3) Grit other than from the Company's Works, such as road grit, mortar, unburned
coal, soot from domestic chimneys and other dust usually associated with the atmosphere
of an industrial area being deposited in the trays.
(4) Wet weather—inability to collect a fair sample.
In 1928, the Company gave an undertaking to adopt measures to abate the nuisance and
in the latter part of 1929 the necessary building was completed and the apparatus installed.
The method adopted is to divert the flow of the gases on their passage from the flues to the
stack by passing them through a tower. In this tower particles are polarized and precipitated to
a hopper at the outlet of which they are bagged.
The apparatus is in two sections and when completed will be worked independently or together.
At present only one section is electrically equipped and experiments are proceeding before changing
the second section which is now functioning by mechanical means to the electrical process.
The recommendations of the Greater London Joint Smoke Abatement Committee have been
received, and the Council has submitted to the Ministry of Health for approval a byelaw making it
an offence to emit black smoke for a period of two minutes in the aggregate in any continuous period
of thirty minutes.
Noise.—We live in a mechanical age. Noise has assumed such gigantic proportions that
it has become a serious menace to the national health. It is true we have to some extent adjusted
ourselves to the clamour of modern city life, but it is impossible to adapt our mechanisms to many
of the nerve-shattering noises which harass us in the course of everyday life. While we may appear
indifferent to noise, we are unconsciously being affected by it.
An analysis of street noise shews that it is composed of many discordant sounds. We pick
out the intermittent blare of motor horns, the noisy cut-out or open exhaust of the motor car and
motor cycle, the heavy rumble of the omnibus and motor lorry, the ear-splitting clatter of the road
mender's pneumatic drill and the steel-worker's rivetter, the thunder of passing trains and roar of
aeroplanes overhead—all combining to make a modern inferno.
It is common knowledge that constant exposure to excessive noise exerts a harmful influence
upon the mind, in marked contrast to the soothing effect of the quiet country side. The mere effort
of overcoming the effects of noise becomes a serious drain on nervous energy which in sensitive persons
may lead to neurasthenia. We know that noise diverts our attention and makes concentration upon
any task extremely difficult. The more enlightened business firms have long realised that greater
quiet means greater efficiency and have provided against the intrusion of noise from outside.
A fact of even greater importance is that sleep is liable to be disturbed or broken by loud
noise. It deprives the sleeper of that refreshing rest which is necessary for the proper discharge of
the day's duties. Not only is the busy brain-worker adversely affected, but the effect upon infants
and young children is even more serious. On account of their more delicate nervous systems, they
wake tired and listless; in consequence their growth may be seriously impeded. Children thus
exposed to disturbing noises within or without the house are apt to grow up nervous and irritable
and unable to derive proper benefit from instruction at school. Expectant mothers especially require
eight hours uninterrupted sleep daily in order to cope with the increased demands made upon their
physical and mental energy. Finally there is the invalid at home or in hospital whose recovery may
be seriously retarded or made impossible by constant exposure to nerve-racking noise in the vicinity.
Although these facts are well-known they are not sufficient to justify legislation without the
support of scientific evidence. Further, noise made by barking dogs or crying infants may be
extremely annoying but it is hardly possible to legislate for them. Again, the strumming of a piano
may be music to one person and agonising torture to another. Thus it is important to discriminate
between inevitable and preventable noise, to discover the particular noises responsible for undesirable
results and to suggest practical methods for their prevention or control.
A special meter has been devised which converts sound waves into electric waves which in
turn can be accurately measured. Numerous experiments have been carried out to determine the
effects of noise upon the human body. They are summarised as follows:—
(1) A newly born infant shows a distinct fear reaction at the sound of a loud noise.
(2) Noise raises the blood pressure and especially the pressure upon the brain itself.
(3) Noise insufficient to wake a sleeping person will cause the muscles to become tense
and to remain tense for as long as 30 minutes before they relax.