The Rock Island Argus and daily union. (Rock Island, Ill.) 1920-1923, 1920-07-31
Frederic Haslxin's Lettel|
Keeping The Water Pure.

much space for spr adink =. .
the sand sleeves. The Arss
method substituted q tank - -
Reservoir method. and pruvi6oe
the cleaning Of the sand si. \
Within the tanks which one - =
the high ground back Of any NJ.
can city 10 one Of these rapi1 ~
sleeves. Into this tank q $780,,
has been introduced to taksSx.
place Of the schmutzdecke -.
chemical Is nothing more ~
alum. In all water there ID p
tain amount of lime, and -
alum comes into contact vitAss'.
precipitate is formed which 3.
verts the sard into an eaecs1
germ strainer.
Current Works Roth ways.
Only q given amount Of ~.
however, can be run through ~
strainer until the sand beccmSs !.
full Of impurities that It celsea :
function effectively. Here, -
ever, the American method - |
the emergency. BY a clever aSGE
ance tn" current Of water d
versed and Is sent forcefully =
through the sand from the bottoc |
It removes all the impurities - |
alum-like precipitate, and nusir
them from the tank. Thus q,
strainer is made as good a. ntv
and the water is started throush1
again for elective publication.
There is now famine in the sah|
ply of alum for use in the tsah !
through which the water supplis
for municipalities are strained. III
alum comes from q clay known d
Bauxite, the chief source Of supsb
Of which is in the vicinity Of Eitl
Rock, Ark. One Of the CHIEF ain
factories in the country is locasa
near Philadelphia. This factory n
quires four carloads Of clay q a.
OF late, however, it has beea n
ceiving but eight carloads . moan
Similar conditions exist elsewhesa
Cities are finding it impossible b
get their um, and the menace d
pestilance is increasing daily.
There is, however. q later deya
opment in the work of water pnt
| fication, also of American oriyh
which Is coming into general a
and which is almost miraculous n
the little town Of Dunwo0die, b
New York. the two great aQuedEa
that carry the water for the mstrgt
oils from Croton re- .rvoir col
very near together. This vatn
supply has not been filtered. ~
until it reaches Dunwoodie It b.
not been treated to make it sall
for the millions who are to drink L
! At Dunwoodie a little house \
built between the two squeducd
This house is a repository Of cst
tain tanks OF vital liquid. From
these tanks there comes forth drol
by drop the particles OF this mcs
powerful disinfectant It is Glutsl
by water. and a little stream Of
goes each way into the great aQus
ducts. These little streams puEit
the stupendous amount OF wais
that New York uses. and makes
one of the safest cities from typhos
in all the world.
What the Germans Used
:, The vital liquid referred to
chlorine. It Is the same matefia
made from salt, which the ca
mans unleashed upon English q
Canadian troops ON that me>
able day in 1915 when the begS
ming Of the greatest horror OF N
was perpetuated. The materials
the tanks at Dunwoodio. howevs
are UNNECESSARILY more dead
than chlorine gas. They ara
| fact, chlorine gas compressed q
til it has become a liquid. Al
liquid inflnitesimal quantities Of
in the water mean death to .
germs which carry contagfon.
These small quantities. howeve
are not sufficient to produce any .
| feet upon a human being VI
}. drinks the water. Chlorine mig
be added until its presence Goa
be determined by taste, and stu
I would not be detrimental to u
person drinking 1t. AS a disinfe
tant, however, II Is without
equal, and with the development
!. the present method Of introducil
| It into water supplies II is the mo
effective, most economical a
. most reliable method Of safe-guar
| inO Our vatpr SunDlY