OCR Text |
Show 193 termed the volume method, where the silt is allowed to settle in a can and you determine the volume; or it can be determined by weight, the per cent by weight, which is now the practice in the Survey, to determine the silt by weight. Q Well, as I understand it, at certain depths in the river you get different quantities of silt. A You get different quantities of silt, and the more recent observations are so made that the attempt to determine the average silt content, day by day, is in per cent of weight. Q So that the calculation that appear in your report with reference to silt are based upon scientific observation? A The estimates as to the amount of silt carried annually by the Green River are based on scientific investigation, yes, sir. Q As I understand it, this silt in the river may come away upstream from its tributaries? A The amount of silt that I show here on page 78 of my report, Bulletin No, 67, of the Department of Agriculture, entitled, " Silt in the Colorado River," which is an exhibit in evidence -- I do not know the number -- indicates that there may be between 10,000,000 and 30,000,000 cubic yards of sediment carried annually into the canyon at Greenriver. By Mr. Farnsworth: Q. It may be between 10,000,000 and 30,000,000? A Yes, sir; it may be between 10,000,000 and 30,000,000. 2156 |