Evening star., 1901-02-20

in Lawrence 1t has not been demonstrate
ed that the mechanical filter reduces the
mortality of typhoid fever and before we
can tell whether the mechanical filter is a
good filter or not for that purpose it must
be tried on a large scale in large cities, and
therefore if we adopt the mechanical filter
in Washington we will be experimenting
and we will be doing what the world would
like us to do. trying the mechanical filter.
DR.. Percy Hickling described the use Of
the slow sand filtration system in London,
which sixty years ago was in the same
position as we are today-in danger of an
outbreak of infectious disease. due to the
contamination of the water with disease
germs
The Englishmen were not bothered with
any idea of mechanical filtration. They
knew that their best water came from the
ground and they also found by close OBJ
servation that disease did not result from
drinking it. They therefore believed that
If they could treat their river water in the
same way, that is by passing it through
the ground, they could get purer and
better water. So they constructed what is
called a filter bed TO initiate natures meth
DDS London today enjoys the purest wa
ter from the most contaminated source of
any city in the world
Rapid Sand System.
Col. a. NJ. Miller of the corps of engi-
neers described the experiments with fill
tration systems In the District. He said
among other things:
I'm approaching the subject, I wish to
say, first that there is no doubt in my
mind-and no doubt. l believe, in any ones
mind who has made the subject study
that where water may be filtered equally
well by either method, or by both methods
of filtration, the slow sand process
is by all means the most advantageous and
the proper one to be adopted. Now, how
ever, there are cases where you have a
water to be treated like a disease; one rem
edy will do and the other will not. The
Potomac water has shown by experiment,
conducted through eight months, where we
went through a period of turbidity which
has been the greatest / have known since
I have been here. and lasted quite while.
that it cannot be filtered satisfactorily by
the slow sand process, but that it can be by
the rapid sand process. or the American
system
Dr. Woodward, health officer of the Dis
trict said, in part:
To-day we know positively, from the ex-
perence of those European cities which
have used slow sand filters, that the ty-
phoid fever death rate is reduced. We
know from the experience of the small
American towns-and it is chiefly small
towns which have used the mechanical
method-that the death rate from typhoid
fever may possibly be reduced. but there
is no evidence that it will be reduced to the
same extent that it has been reduced in
the European cities. The weight of the ev-
idence seems, therefore. to be in favor of
the greater efficiency of slow sand filtra-
ton.
by taking the figures for the days. as
set forth in the table. on which both filters
ran side by side we find that there was a
smaller number of germs from the eff1uent
from the slow sand filter than there was in
the elIluent from the mechanical filter. [
have gone over the figures in Col. Millers
report in various ways, and in no way-eX-
cept in what l have characterized as an
arbitrary and, l believe, unreasonable,
method-can the superiority of the mechan-
ical filter, from a meteorological stand
point, be demonstrated"