The role played by the medium and fine silt and clay contents in determining the quartiles and the degree of stratification from a cumulative particle-size curve was studied in order to determine what time savings could be made in the sedimentation phase of soil mechanical analysis. The clay content of the samples was, in general, found to be so small that it did not affect the parameters studied. In contrast to this, the medium and fine silt content affected the lower quartile of the distribution for many soils classified as finer than medium sand. Consequently, only the omission of the determination of the clay fraction can be recommended as a time-saving measure in mechanical analysis.
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