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189
the past year has on the whole been less favourable for
the operations of those Companies which abstract water
from rivers, than that prevailing in the previous year,
but that nevertheless the improved quality of this
water has been fully maintained.
All the samples examined were taken directly from
the mains of the several Companies. In addition to
the chemical analysis to which each sample was submitted,
the temperature of the water as it issued from
the main, at the time of its collection, was determined,
and the appearance which it exhibited on being viewed
in a two-foot tube recorded.
Temperature: Although the average temperature
differs but little for the several supplies, the monthly
variation in the case of the river waters is very great,
whilst the temperature of the deep-well water is practically
constant throughout the year. Thus the water
principally derived from the Thames and supplied by
the Chelsea, West Middlesex, Southwark, Grand
Junction, and Lambeth Companies, varied in temperature
from 66°. Fahr. in August to 37°. Fahr. in
December, and the water from the Lea distributed by
the New River and East London Companies fluctuated
from 65°.3 Fahr. in August to 38°.3 Fahr.in December.
The deep-well water of the Kent Company on the
other hand, was free from these violent fluctuations,
and practically maintained a constant temperature
throughout the year.