348 On the Water of Tunbridge Wells. 
sequent filtration, I would not suffer any cock to be fixed to the 
pump, but had a proper lift and force pump put down to force 
the water into an open cistern in the house, where it would 
remain for some time before it was drawn off from the pipe in- 
serted in the bottom of the cistern, and ending with a stop cock. 
In this way no water could be used before time was allowed for 
the escape of the carbonic acid, and for the precipitation of the 
‘iron; but as the iron in being precipitated to the bottom of the 
cistern would readily pass off with the water drawn from the 
conveying pipe and render it thick, and therefore unfit for use, 
I directed a cone-shaped instrument to be made, pierced with 
very minute holes, as a strainer, and with a stem about three 
inches in length, thus 
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The stem was tightly fixed into the hole of the conveying pipe, 
and as the strainer was two or three inches above the bottom of 
the cistern, the iron in being precipitated would fall below it, 
and would not pass off with the water; but as some of the iron 
in a state of suspension might, nevertheless, still escape through 
the strainer, I shall have one made in such a way as to allow of 
a piece of sponge, of sufficient size to fill its cavity, being put 
into it. An abundant supply of soft water will be thus easily 
procured for every domestic use, and freed likewise entirely 
from the iron which will be arrested in its progress to the con- 
veying pipe by the sponge in the strainer: the water remaining 
in the cistern, does perfectly well for the offices in the house, 
to which it is conveyed by another pipe. Upon a trial of the 
strainer, even without the sponge, it was pleasing to observe the 
water come out clear from one pipe, while from the other it was 
thick, as was believed would be the case. Thus, with scarcely 
any trouble, and at the most trifling expense, an abundant 
supply of soft water may be had, and to make security doubly 
sure, the water might be subsequently filtered in a stone jar, 
for drinking. As almost all the water used at Tunbridge 
