The visual-tube method for sedimentation analysis of sands was developed as a part of the general investigation titled "A Study of Methods Used in Measurement and Analysis of Sediment Loads in Streams." The method is one answer to the need for a simple, rapid, and inexpensive means of determining the sedimentation-size frequency analysis of sand samples containing particles less than one millimeter in size. For analysis of coarser sands see the Appendix, Section 13, Report No. 11 "The Development and Calibration of the Visual-Accumulation-Tube" is available for those who have further interest in this analysis.
The personnel who will be operating these units may have little or no previous knowledge of either the principles involved or the details of opera.ting procedure. This manual is intended as an aid to them in setting up the apparatus, learning the analytical procedure, interpreting the results, and understanding the primary principles encountered.