View report page

32
top end bushes for connecting rods of Diesel engines was attributed to the
use (due to wartime conditions) of a poor quality alloy; the grain size was
also unusually large and the workmanship on the casting poor.
"(6) In conjunction with the Public Control Department, several cases
under section 143 of the London Building Act, 1930, were investigated, this
referring to 'dangerous businesses' and the statutory requirements designed
to protect public safety. The various premises were visited and their
methods of operation inspected; samples of the materials used were also
taken for examination in the laboratory. Considered opinions were
expressed as to the degree of danger in each case. Instances were (a) premises
dealing with the mixing and blending of waxes and oils; (b) premises
using gas heaters in a cellulose lacquer spraying shop.
"(7) The presence of plant-growth substances (auxins) in sewage
products (e.g., sludge, composts, etc.) was investigated, and a paper on the
subject was published in a scientific journal. The results showed that most
products contained auxins in very small but measurable amounts : also that,
although both crude and digested sludge may, in the wet state, contain a
relatively high amount, most of these growth-promoting substances are
decomposed during the normal drying of the sludges.
"The regular examination of the drinking water at Council hospitals, etc., served
by private wells was continued; in all cases chlorination is applied. Drugs and
medical stores, foodstuffs and milk were examined as to quality, and as to compliance
with specifications. The condition of the water in swimming baths and the effectiveness
of the chlorination treatment were examined and the regular testing of the air
in the vehicular tunnels at Blackwall and Rotherhithe as to its carbon monoxide,
black suspended matter, lead content, etc., was continued; it was shown that the
ventilating plant had maintained the atmosphere in a satisfactory condition. Statutory
work under the Petroleum (Consolidation) Act, 1928, the Petroleum (Mixtures)
Order, 1929, the Public Health (London) Act, 1936, the London Building Act,
1930, the Fertilizers and Feeding Stuffs Act, 1926, etc., was carried out as required,
and the air examinations in various parts of the county in connection with the problem
of atmospheric pollution were continued, in co-operation with the Department of
Scientific and Industrial Research. Among the many other matters dealt with
during the year were the analytical control of steam-raising plants, etc., at hospitals
and institutions, the analysis of metals, building materials, paints, detergents, oils,
clays and subsoils, the testing of safety lamps and the atmospheric conditions in the
plants at licensed dry-cleaners' premises.
"The development of new analytical methods was kept under review and, the
use, for example, of the quartz spectrograph was widely extended. In connection
with a suspected case of lead poisoning the methods available for the determination
of lead in very small amounts were critically examined and a successful chemical
technique was devised involving certain modifications of the usually accepted
procedure.
Sewage
disposal
"The necessary analytical work in connection with the control of sewage disposal
was continued. In addition to the primary sedimentation process by which the
sewage was treated at both outfalls, part of the flow at the Northern Outfall Works
was further subjected to secondary sedimentation. At the end of the year preparation
was being made for the recommissioning of the activated sludge plant at these
works, a stock of activated sludge having been kept in condition over a long period
by a small degree of mechanical agitation so that it would be available for the restarting
of the plant at short notice. The sludge digestion plant continued to function
satisfactorily and produced a reasonable yield of gas: it was recommended that
economy might be obtained by lowering the operating temperature from 100° F.
to 85° F. and, controlled comparative tests on one unit having shown that this could