Page 167

Whitney—Microstratification of Lakes 
167 
 LARE MENDOTA - 
STATION 2 
OGT.3 936. 
TRAN5~RENGY SCATTCR$NG 
IQ 
15 - 
2O~ 
f~ 
25 
FIG. 7. Transparency and scattering curves for Lake Mendota. 
this depth, but it rises only to a maximum and then falls again. In the lower
water the scattering is less on the average than that above. In some other
sets of readings, there have been instances in which large changes in transparency
are accompanied by no detectable changes in scattering. A large increase
in the amount of highly colored dissolved material - in a lake would reduce
the transparency but might also reduce scattering. Hence transparency and
scattering curves might be antisymmetrical or similar depending on the amounts
and kinds of materials immersed in the water at different depths. A comparison
of such curves yields more information than either type taken alone. 
 Organic content. In the latter part of September, water samples were taken
in an effort to discover correlations between transparency maxima and minima
and organic content. One liter samples of water were centrifuged and loss
in weight measured when converting the centrifuged material to ash. Results
so far obtained are inconclusive although some evidence points