56 BULLETIN 832, U. S. DEPARTMENT OF AGRICULTURE. 



MAIN CHANNEL NEAR FELLSMERE. 



The slope course on this channel was straight and was 2,000 feet 

 long. The gauging station was located about 100 feet below the 

 downstream end of the slope course, which was about 3 miles north 

 of Fellsmere. The gaugings were made from a footbridge about 10 feet 

 upstream from the county highway bridge and supported by suspen-' 

 sion brackets from the piling of that bridge. The channel was quite 

 uniform in cross section, there being only one rather abrupt variation,' 

 which occurred near the upper end of the course (figs. 12 A, and 12 B). 

 The bottom of the channel was broad and regular and quite evenly 

 covered with sand. The side slopes were fairly regular and prac- 

 tically free from vegetation in the lower part of the channel, but 

 rather irregular and covered with vegetation in the upper part (fig. 

 11-4, and Plate XVIII, fig. 2). With the exception of measure- 

 ment 10, Table 6, for which the highest value of n was obtained, the 

 measurements were made for stages almost wholly in the lower and 

 better part of the channel. For the same part of the channel the 

 values of n obtained during 1917 were somewhat lower than those 

 obtained during 1916. This might be attributed to the fact that the 

 cross section had become somewhat more uniform between the dates 

 of the two sets of measurements, as appears from the graphs shown 

 in figures 12 A and 12 B. 



MAIN CHANNEL NEAR VEIiO. 



Gaugings of this channel were made from a suspension footbridge 

 near Vero. The upper end of the slope course, which was 1,000 feet 

 long, was located about 40 feet downstream from the gauging station. 

 The bottom was sandy, and there were several flat, broad sand bars 

 in the channel during low water (Plate XIX, fig. 1; and fig. 11 B). 

 There was some vegetation in the channel, which can be seen in the 

 view just referred to. The cross-sectional area of the channel was 

 quite uniform except for the lowest measurements, Nos. 11 and 12 (see 

 Table No. 6 and figs. 12 C and 12 D). The side slopes for the three 

 low-stage measurements made during 1916 were fairly regular, but 

 for the three higher stage measurements, Nos. 14, 15, and 19, made at 

 about half-bankful stages, the slopes were quite rough and irregular, 

 owing to the fact that large lumps of the bank had sloughed off. The 

 values of n obtained indicate that the retardation to flow was much 

 greater in the upper part than in the lower part of the channel, which 

 was apparently due to the caving of the banks in the upper part of 

 the channel. 



MAIN CHANNEL NEAR PORT TIERCE. 



Gaugirigs of this channel were made from a suspension footbridge 

 located about 3 miles west of Fort Pierce. The upper end of the 

 slope course, which was 1,032 feet long, was located about 25 feet 



