notwithstanding its considerable percentage of salt, have cooled sufficiently for the surface layer to freeze.
The soundings we secured along this new line were as follows: 3.17, 3.63, 3.95 4.48, 4.99, 5.6o, 9.03, 16.66, 18.58, 19.88, 20.98, 23.07, 24.03, 23.67, 23.16, 22.40, 21.52, 2I.oi, 2I.00, 19.11, and 7.75 m. Thus at first the depth increased but slowly, but afterwards more quickly until it reached its maximum of 24.03 m., this being a good deal nearer to the northern than to the southern side. From this deep trough the bottom of the lake rises slowly towards the northern shore, until at only 1.25 km. from it the depth is again 19.II m. Thus the northern part of the lake is deeper than the southern; nor could anything else be expected when the general shape of the great Kum-köl basin is borne in mind : the Kalta-alaghan being relatively close to the northern shore, while the first chains of the Arka-tagh rise at a considerable distance from the southern shore. Between the southern shore and the deep trough there is curiously a steep slope, which presented precisely the same characteristics and occupied precisely the same position along both lines of soundings; but then they happened just there to approach pretty close together. Along the eastern line, proceeding from south to north, we have the soundings 5.48, 9.81, and 16.75 m., while along the western line the corresponding soundings were 5.6o, 9.03, and 16.66 m. In other words in a distance of only II/2 km. the lake drops I I m., while from the southern shore to the edge of this abrupt declivity, a distance of 5',12 km., the fall is only 5.5 m.
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