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In 1897 this silt, to within 2 miles of the head of the lake, was a fine, impalpable, absolutely gritless deposit, and where newly exposed would not bear an appreciable weight on its surface. The writer has often tried its resistance all along the lake, and an oar could be driven into it several feet with moderate pressure. Shovelfuls of it placed upon boards in a heaped-up mass would immediately settle and spread so that the upper surface was almost horizontal. A barrelful of it, when first taken up at Santa Monica Springs, soon spread out in a flat sheet. At the head and for about 2 miles down the lake the silt consisted of a sand which readily deposited when the velocity of the stream was checked by the waters of the lake. At occasional points below the head of the lake small bars of sand were found near the mouths of small canyons or creeks.

From March 15 to April, 1899, the water level of the lake was a

little more than 10 feet below the crest of the dam. The water again commenced flowing over the crest of the (lain on April 21 and continued to flow over, at small depths, until June 7, when the river rose to a height of 9.8 feet above the crest of the dam. This flood continued until June 12, and its effect on the cross sections near the head of the lake was marked. The sections at stations 14.6, 15.9, 17.4, and 18.9 were scoured out 2 to 3 feet deeper than the sections of 1897, and at station 15.9 a sand bar was deposited on the inside (left) of the curve of the river, contracting the channel to less than half its former width.

The typical section illustrating the ratio of silt and water areas for the whole lake is about midway between stations 5.6 and 7.0, i. e., about one-fourth of a mile below the Chautauqua wharf. Fig. 7 illustrates this section, the vertical scale being magnified ten times.

Fig. 2 shows the configuration and geography of the lake formed by