26 HISTORY OF COLCHESTER CORPORATION WATER WORKS.
This is unusual, but where the water comes from, and how
it gets into the clay, will probably interest our geological friends.
The section of the old well is mentioned in the Geological
Memoir, Colchester (1880), but it does not quite agree with my
section of the new well, which is now published for the first time.
Ground surface (Top of Brickwork of New Well) 35.7ft. above O.D.
When one is investigating a new underground source of
supply, the first anxiety is to ascertain the quality of the water;
secondly, the maximum daily quantity obtainable from the
source without entrenching on the next day or month's supply ;
thirdly, if a well supply, to see that the natural or rest level
of the water is not permanently affected by pumping. Seeing
the importance of this latter, an electrical automatic recording
apparatus was arranged in the well, so that the level of the
water is recorded every minute of the day, whether the pumps
are at work or at rest. This record has been continued by Mr.
Bland, so that he now has an unbroken record for the last 22
years of the behaviour of the underground chalk water under
Colchester. I am not aware of any other similar record existing
in this part of East Anglia, and if it is of interest to the Club,
the Corporation might be persuaded to supply a copy.
Colchester appears favourably situated as regards obtaining a
supply of water from the chalk, and so far as I have been able
to ascertain only one bore hole in the Borough has actually
turned out a failure, and that was the boring put down by the
Government at the Cavalry Barracks, but if I am correctly in-
formed, there is another boring lately put down on the opposite
side of the valley, even at a greater elevation, which does not
yield the quantity anticipated. Why this former boring