line which took a little more than an hour, the maximum depths of 16.88 and 16.53 m. were sounded about halfway, and on the second line the depth diminished in the direction of our course: 15.15, 15.01, I3.60, I2.55, etc., the greatest depth being not far from the northern shore, where the mountains were steep. At 1 o'clock p. m. we had a temperature of 6.7° in the lake and of 3.5° in the air.
Steering S. 24° E. we finally reached what we supposed to be the southern shore of the lake, and there the night was passed. By nearer examination it proved, however, to be only a long narrow peninsula from the western shore, pointing straight to the east, and dividing the lake into two basins, the southern a little smaller than the northern. On the shore ducks were seen, as previously on Lake Lighten. The beach was of the same kind as at Camp XXIII, a wall rather than a terrace.
On September 291h the southern basin was examined. The course now was 3 km. S. S. W., 3 km. S. 87° W., 4.5 km. N. 55° E.. and 4.7 km. nearly north.' On the second of these lines the greatest depth was 13.65 m. At the western shore there are four very regularly built terraces, each about 2 m. high. From the slope above them, Pan. 4o, Tab. 7, was taken, giving an idea of the hills surrounding the southern part of the lake. To the N. 55° E. the narrow sound is visible joining the two basins. Wild yaks were seen to the S. E. On the third line, to N. 55° E., back to the sound, the greatest depth was r 9.0 m. which proved to be the maximum depth of the whole lake. At 1 o'clock p. m. the temperature was 6.3° in the water and 1.9° in the air. The sound is about 6o m. broad, and the comparatively great depth of several meters in its middle may depend upon currents caused by different winds. With a strong S. W. wind the water will be driven from the southern to the northern basin, and with a N. W. wind from the northern to the southern. Thus the fine deposits in the sound are continually washed away. On the course to Camp XXV we kept near the eastern shore where the depth nowhere exceeded 3 m. On the way the delta of a brook is passed. This brook comes from the E. N. E. and reaches the lake in a rather broad channel, surrounded with flat banks of silt and sand. Camp XXV was pitched in the N. E. corner of the lake. At 63/, o'clock p. m. the usual storm came from E. N. E., a direction which during several days had been prevailing in the evening and most of the night.
On September 3 ollt our march goes E. N. E. in a nearly straight line for 16.2 km. to Carltp XX VI. Near this camp the boundary threshold of the basin of Pool-tso is crossed at a height of 5,239 m. The height of Camp XXV is at 5,083 m., or 6 m. above the surface of the lake. From Camp XX V to the threshold, a distance of 14.8 km., the ground, therefore, rises 156 m., or as r : 95. From the threshold to Camp XXV/ is 1.4 km. or a fall of 98 m., as the camp is at 5,141 m.; the rate is here as I :14.
IIIFカラー高解像度
