Seasonal Variations — Tseu 
289 
TABLE 2 
Diurnal Changes in Oxygen Content 
DATE 
TIME 
OBSERVED 
VALUE 
COMPUTED 
SATURATION 
VALUE 
PERCENTAGE 
SATURATION 
1400 maximum 
ot/./L. 
5.29 
ml.lL. 
5.08 
104 
December 27-28, 1949 
1800 median 
4.70 
5.10 
92 
0500 minimum 
4.10 
5.14 
80 
1600 maximum 
5.41 
5.04 
107 
April 28-29, 1950 
0200 median 
4.82 
5.11 
94 
0700 minimum 
4.23 
5.10 
83 
1800 maximum 
4.82 
4.65 
104 
August 25-26, 1950 
2200 median 
4.43 
4.71 
94 
0600 minimum 
4.02 
4.79 
84 
60) for the minimum, median, and maximum 
oxygen content values in each of the 24-hour 
cycles. Results tabulated in Table 2 show that 
the minimum morning values represent un- 
dersaturated waters and the maximum after- 
noon values represent supersaturated water. 
All three observations show a similar cycle 
Fig. 15. Comparison of oxygen content for a year 
at stations 1, 5, and 10. Oxygen content of surface 
waters shown by broken line, of bottom waters by 
solid line. Unless otherwise indicated, samples for the 
first 5 V 2 months were collected in the afternoon, there- 
after in the mornings. 
with regard to the amount of oxygen dis- 
solved in the water. 
At monthly intervals for over a year anal- 
yses were attempted for the nutrient salts, 
phosphates, nitrites, and silicates. As the ana- 
lytical methods were colorimetric, attempts 
were first made to measure the color intensi- 
ties with a Klett-Sommerson photoelectric 
colorimeter, test tube model. Because of the 
Fig. 16. Comparison of oxygen content for three 
diurnal observations. Oxygen content of surface waters 
shown by broken line, of bottom waters by solid line. 
