Vilas County news. [volume] (Eagle River, Vilas County, Wis.) 1896-1927, 1908-09-16
MORE THAN FOUR MILLION PEG.
PIE ARE SUPPLIED FROM
THESE SOURCES.
INTERESTING FACTS SHOWING
THEIR ADAPTAsILITY FOR
DOMESTIC USES.

boundary of the United States. and
Doller water for the enormous land
and water traffic that joins these cit
les to one another and to the rest of
the world is derived from the same
source. The chemical composition of
these waters is therefore a matter of
great interest to both sanitarians
and chemical engineers, and a study
OF that composition is also valuable
because the comparative equable con-
EDITION of the lake waters allows
them to serve as a standard for com
parison with other waters in the
northern region.
About two years ago the United
States Geological Survey began a
Istudy of the waters of the Great
Lakes in connection with a rather ex-
tensive investigation of the economic
value Of surface waters in the United
States. For a year a 1-gallon sample
was collected each month from each
lake at a point where the water
would probably represent the normal
quality of the discharge. Samples of
Lake Superior water were taken from
st. Mary's river just above the locks
at Saulte Ste. Marie, Mich; the Lake
Michigan samples were collected
from a ferry-boat in the Straits of
Mackinac; ST. Clair river was sam
pied in midstream at Port Huron,
Mich; Lake Erie was sampled at the
Buffalo IN. " waterworks intake;
and st. Lawrence river was sampled
lat Ogdensburg, N Y, since no i'm
portant streams enter between that
Icity and Lake Ontario. The waters
were shipped in special containers to
the water-testing laboratory of the
Survey at Washington, D. c., and
were analysed from one to three
months after date Of collection. Sus-
pended matter was removed before
the samples were evaporated, and
standard methods of water analysis
were followed when practicable.
Mr.. R. B. Dole, under whose direc-
ton the analyses were made, states
that the most noticeable feature in
Icursory examination of the analyti
cal q is the slight variation in the
concentration of the waters from
month to month, the total variation,
as shown by the dissolved solids fig
lures, being only Il parts per million,
or Is per cent AS rivers of ordinary
size may vary 200 to 800 per cent,
and even large rivers, like the Mis-
sissippi, may change so per cent in
their mineral content during the year,
this annual fiuctuation of Is per cent
is very small. The average monthly
f1uctuation in the discharge of the
Great Lakes is considerably more
than Is per cent, ranging from 40 per
cent in st. Mary's river to q per cent
in st. Lawrence river at the foot of
Lake Ontario The chemical compo-
sition Of the water does not, therefore,
bear a fixed relation to the quantity
of water discharged. Mr.. Dole gives
as the probable reasons for this com
parative steadiness in concentration
the absence of large tributaries and
the low ratio between the areas of
the drainage basins and the lake sur
faces.
Though the lake waters do not
change greatly from month to month,
they differ a great deal from one an
other in concentration. Lake Supe-
rior is least strongly mineralized;
Lake Michigan is twice as high in to-
tai solids, and Lake Huron is but lit
tie less mineralized than Lake Michi-
can. Lakes Erie and Ontario are
practically alike in mineral content,
holding about 21a times as much sol
ids in solution as Lake Superior
Reason for the striking difference in
the lake waters is found in the char
acter of the geologic formations in
the drainage basins tributary to them.
The crystalline and igneous rocks
granite, schist, gneiss, and basalt-
that predominant all around Lake Su-
perior are not easily soluble, and
thence the lake receives few affiuents
bearing large quantities of dissolved
matter; Lake Michigan and Lake
Huron. on the other hand receive
stones of the sedimentary series and
contain much greater proportions of
mineral matter. Dilution by the
softer water of Lake Superior prob
ably accounts for the fact that Lake
Huron water is less mineralized than
that of Lake Michigan. 1t is prob
able that forestation sedimentation,
and relation of rainfall to run-off also
affect the relative composition of the
lake waters.
| Comparison of the analyses of the
lake waters with those tributaries
to the system shows, according to Mr..
Dole. that the lakes are almost inva-
riably softer than their affiuents.
The reason for this difference is ap-
parent. AS the lake surfaces are
large in proportion to their CORES
ponding land drainages, a great part