Beginning at 50 hours along range 5 (slightly earlier along ranges 7 
and 9, and later along ranges 1 and 3) the outer inshore became more un- 
dulating; i.e., a bar developed at the outer end of the outer inshore 
region and a fairly deep trough developed between the bar and the inner 
inshore region. The depth of the trough increased as the experiment 
continued. The trough developed first along ranges 7 and 9 at 45 hours, 
along range 5 at 50 hours, along range 1 at 55 hours, and along range 3 
at 60 hours. This is indicated by the multiple intercepts at -0.8 foot 
in Figures 15 to 19. 
The trough eroded to elevation -0.9 foot at 50 hours along range 9, at 
70 hours along ranges 1 and 3, at 75 hours along range 7, and at 80 hours 
along range 5. Elevation -1.0 was reached first along ranges 1 and 9, 
and last along range 5. Along ranges 1 and 9 the trough reached elevation 
-1.1 at 115 hours. Thus, the erosion of the trough started first along 
the outside ranges and progressed toward the center. 
(3) Offshore Zone. The offshore zone was a zone of deposition, as 
indicated by the downward-sloping lines for contours deeper than -0.8 
foot in Figures 7 to 11. The deposition began first at the higher eleva- 
tions (-0.9 to -1.4 feet) with the greatest rates at the higher of these 
elevations. The deposition began after 10 hours at the lower elevations, 
extending progressively from -1.4 to -2.2 feet, as shown by the closer 
spacing of the deeper contours in Figures 7 to 11 as the experiment con- 
tinued. 
The deposition rate at -1.0 foot, for example, was high initially and 
then began to decrease. The contours for -0.9 to -1.3 feet were approach- 
ing horizontal during the last 5 to 10 hours, indicating that the shore- 
ward edge of the offshore zone may also have been approaching an equilib- 
rium position. 
Movement of the -0.9-, -1.4-, and -2.1-foot contours along the five 
ranges is compared in Figure 21. At all three elevations, the lines for 
the five ranges are fairly close together (within 0.5 foot), indicating 
no significant lateral variation in the amount or rate of deposition in 
the offshore zone. 
3. Sediment-Size Distribution. 
The sand for these experiments was the same sand used by Savage (1959, 
1962) and Fairchild (1970). In Volumes II and III, the median grain size 
(sieve method) for the sand was reported to be 0.23 millimeter. A total 
of 16 samples was collected along the full length of the profile before 
the start of this experiment. Four of the samples were analyzed by the 
Sieve method; the average median grain size was 0.21 millimeter, 0.02 
millimeter less than the earlier experiments. The sieving results are 
given in the Appendix. 
All samples collected for this experiment were analyzed by the Visual 
Accumulation (VA) tube method, and 10 percent of the samples were also 
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