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does in general give a useful indication of the extent of pollution by deposits.
The Lead Peroxide Instrument is a small cylinder coated with lead peroxide and
exposed to the air, although protected from rain. The sulphur dioxide in the
air reacts with the coating to form lead sulphate, which is determined by
analysis after a suitable period of exposure. The analyst's findings are
expressed as "milligrammes of sulphur trioxide fixed per day per 100 square
centimetres of Batch "A" standard lead peroxide". By the use of this method
it is possible to compare the intensity of pollution of the air by sulphur at
different places and times.
Samples from the Council's two stations are sent to the Council's Public
Analyst at monthly intervals and the results of the analyses are reported to
the Public Health Committee and also sent to the Director of Fuel Research, the
Department of Scientific and Industrial Research, Fuel Research Station, East
Greenwich. That Department publishes a monthly "Bulletin" in which are
reported the results of analyses from all stations throughout the country. A
table of monthly findings from the Atmospheric Recording Stations in Hackney is
given on Page 17 of the Appendix.