. Journal and proceedings of the Royal Society of New South Wales . 1 profile convex to sky. This lower convex portion beauti-fully scalloped with cusps. During the night a heavier wind had sprung up and piledup the sand seaward of the ledge especially near low watermark. Towards morning the cusps had then been developedunder a falling wind. January 12th.—Tides decreasing, wind moderating, 25miles an hour from Ledge of erosion cut in theerosion bench of January 11th. This ledge front in planwas notched with slight cuspate indentations possessingsuccessive widths of 20, 20, 20, 25, 25, 2
. Journal and proceedings of the Royal Society of New South Wales . 1 profile convex to sky. This lower convex portion beauti-fully scalloped with cusps. During the night a heavier wind had sprung up and piledup the sand seaward of the ledge especially near low watermark. Towards morning the cusps had then been developedunder a falling wind. January 12th.—Tides decreasing, wind moderating, 25miles an hour from Ledge of erosion cut in theerosion bench of January 11th. This ledge front in planwas notched with slight cuspate indentations possessingsuccessive widths of 20, 20, 20, 25, 25, 25, 25 paces. Cuspsalmost absent. Breaking wave travelled along-shore fromN. to S. at about four or five miles an hour, while eachwave instead of continuously breaking approached the shoreline in a manner somewhat en echelon (Pig. 6), and chasedeach other along the beach before the wind in a directionas from south-east to north-west. The backwash traversedthe beach in successive ridges or waves running to or forming cusps in the Fig. 6.—Method of wave approach on Lady Robinson]s Beach duringheavy cross —Wave front. AB C — Breaking line. 00 —Travel along shore ofbreaking woive ABC. R—General direction of wave motion. B—Directionof small cross waves. R—Direction of wind. Small cross bars along ABCrepresent cross waves into vihich ABC vms divided. January 12th -24th.—About January 16th a blacknoreaster (gale) obliterated all cusps. Breakers travelled 172 E. C. ANDREWS. along beach about 100 yards a minute from north to short cross waves formed one roller. Absenceof wave pulses marked. About January 18th a southerly gale (35 miles an hour).Half tide. As tide rose the breaking waves broke up intoshort oblique waves and ran up and along the beach in anorth west direction. Waves appeared to lack definitepulsating movement and were driven one after the otheralong the beach before the wind. Bench cut nine inches
Size: 2629px × 951px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectscience, bookyear1867
