Waves of sand and snow and the eddies which make them . Plate 53.—Symmetrical ripple-mark produced by waves of the sea ; at Plate 53.—Unsymmetrical ripple-mark produced by waves of the sea. 259 RIPPLE-MARK AND CURRENT-MARK 261 by the swell of the sea in pools off-shore or wherethe waves are not near the breaking-point. Bothare steeper than the sand-ripples formed by asimple current. I measured a series of eighty-sixconsecutive ripple-marks formed by waves on theflat shore of the Mawdach estuary in North Wales,and found that they had an average length of 1-99inches and height of 036


Waves of sand and snow and the eddies which make them . Plate 53.—Symmetrical ripple-mark produced by waves of the sea ; at Plate 53.—Unsymmetrical ripple-mark produced by waves of the sea. 259 RIPPLE-MARK AND CURRENT-MARK 261 by the swell of the sea in pools off-shore or wherethe waves are not near the breaking-point. Bothare steeper than the sand-ripples formed by asimple current. I measured a series of eighty-sixconsecutive ripple-marks formed by waves on theflat shore of the Mawdach estuary in North Wales,and found that they had an average length of 1-99inches and height of 036 inch, so that the lengthwas only 5-53 times the height. The measure-ments were made after the water had receded, and,as the ridges had not preserved the sharp crestswhich they have when under water, I presume thatthe height had been originally somewhat ridges extended in broad, straight lines, andthe wave-length had an appearance of almost per-fect regularity. The measurements gave 10 percent, of the mean wave-length as the averagedifference between the length of succeeding waves. At Felpham, near Bognor, on the Su


Size: 2052px × 1218px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., bookcentury1900, bookdecade1910, bookidwavesofs, booksubjectwaves