OCR Text |
Show 83 Irrespective of scour and fill there is some kind of normal flow . And in the characteristic readings as shown at the gaging stations there is an attempt to show what that normal depth is . Each river has to make its own law , according to the amount of silt in it . They show the depth of the river at these times . . And other plates will give the depths throughout the year at the gaging stations . The original notes of these measurements are kept by the district ( offices offlaces ) . The district offices were asked to supply this officewith depths cross sections of the river at their gaging stations , based upon at least ten measurements , and if those ten ( measure- measure ) ments did not in their estimation furnish typical cross sections to furnish more measurements . , The cross sections are typical . Now , if for any ( i-eason ieason ) they are not typical , the original notes for all of the measurements for all of the stations could be plotted , but even this sheet with ten cross sections on it is pretty confusing . If more wer3 put on , it would be ( almost alinost ) impossible to make heads or tails out of the cross sections . So far as the Geological Survey is concerned these are straight , typical changes in the bed of the river at the gaging station . Some of the district engineers took some periods , and some took otbers . . The figures given at Lees ( Perry Ferry ) by date and by discharge are representative . The dates so taken as to include ( minimum mininium ) and inaximam flows , and |