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33
Parks
Although some work was also done for this department on fertilisers, soils and other
matters the most important aspect of it related to the swimming baths and ponds provided
for public use. The 13 open air baths have chlorination plants which provide continuous
treatment of the water. The Parks Department, Chief Engineer's Department and the
Chemical Branch are all concerned in these operations and close liaison was maintained
which resulted in a high standard of purity of the water being maintained throughout
the bathing season. Frequent tests for free chlorine were done by the staff at the baths
and periodical visits were made by an officer of the Chemical Branch who took samples
of water for chemical analysis and bacteriological examination in the laboratory. The
investigations of a research team including officers of the Chemical Branch and the
Chief Engineer's Department resulted in inexpensive changes being made to some of
the plants which caused a considerable improvement in the efficiency of operation. The
fundamental principles of the chlorination process were studied and it was proved, for
example, that in an open-air bath the action of sunlight caused a greater loss of free
chlorine residual than the impurities normally added by the bathers.
School meals,
education and
children
The work done in co-operation with the Restaurants and Catering Department was
continued and many meals were analysed as to their nutritional value by the determination
of their fat, protein, carbohydrate and mineral contents and their calorific value. The
results generally showed a reasonable approximation to the standards aimed at for the
several nutritional factors for the various age groups concerned.
Swimming bath waters and drinking waters at residential schools were examined.
Pending the authorisation by the appropriate Ministry of the expenditure for installing
automatic treatment plants at these baths, they continued to be treated by an improvised
chlorination system. The research team, already mentioned as working on swimming
baths, devoted considerable attention to those of this type and devised improvements
which, in the case of the particular bath where they were tried, rendered the operation
partly automatic so that the length of period for which the water could be used without
emptying and refilling was greatly increased.
Instructional visits of school parties to both the County Hall and the Northern
Outfall Works laboratories should be mentioned.
Supplies
The materials examined for this service covered a very wide field, and many of then
are dealt with in other paragraphs concerning the services which use them; for example
paints and building materials for housing. Particularly close liaison was maintained with
officers of all branches of the Supplies Department which facilitated discussions on
matters on which a scientific aspect could be helpful.
Many foodstuffs of all types were examined, the main purposes being (a) to allocate
contracts to the tenderers of the cheapest satisfactory material, (b) to check the quality
of deliveries, (c) to investigate complaints and (d) to assess whether new preparation:
could be of potential use in the service. Generally, a high standard of quality wa:
maintained for the foodstuffs in use and there were only a very few justifiable complaints
A careful watch was kept on the quality of the liquid milk supplied and condensed anc
dried milks were examined as required. Other materials which might be mentionec
included chemicals, drugs and medical supplies, lubricating and other oils, floor anc
other polishes, soaps, solders and other metals, etc.
Careful attention was given to the development of synthetic detergents and man)
types were examined though the Council's own specification for a washing-up powder
was still considered to be the most satisfactory. The use of plastics as substitutes for chins
and earthenware in certain instances was investigated and many of the several different
compositions now on the market were examined. For some, for example melamine, the
curing in manufacture is particularly important and under-curing may result in an undue
proportion of the incorporated zinc oxide being extractable by acid liquids
Fire brigade
Much of the work in this field was of a consultative and advisory nature, including
the discussions of the British Standards Institution's Technical Committees on Inflammability
of Films and Definitions of Fire Resistance and Incombustibility. Other subjects
c