BEACH FORMATIONS AT BOTANY BAY. 177 



Waves began to increase in size, but came on beach mainly 

 as swells or pulses. Large cusps still formed at upper limit 

 of beach. Backwash along longer axes of intercuspate 

 troughs very strong with formation of deep wide furrows. 

 Waves gradually growing in iutensity. 



July 16th. — Wind almost gone, slight off-shore wind. 

 Rollers broke on beach and travelled along-shore from N- 

 to S. with great velocity. Great waves commenced to 

 break from 400 to 1,000 yards off-shore. Heavy bay bar 

 apparently formed off-shore. General appearance of beach 

 and bay much like ocean beach in ordinary storm. Waves 

 advanced on to beach in continually foaming stage. (Such 

 features apparently had not been observed in this bay since 

 the great easterly gale about May 1889). Lady Robinson's 

 Baths and Pier partly demolished — wide flattish beach 

 formed and sand dunes cut back. Cusps gone. Waves 

 dashed on beach tumultuously but advanced with fronts 

 scarcely indented (at half tide). Beach smooth and abnorm- 

 ally raised as to its middle and seaward portions. 



High tide about 11 p.m. No wind. Waves at maximum 

 height. Appeared to be 25 feet from low water mark to 

 crests. No sign of cusps. Waves rushed up beach with 

 non indented fronts. Cliff from 8-14 feet high cut in sand 

 dunes. Beach smooth, and convex to sky. Large stones 

 torn out of retaining walls up to 120 lbs. 1 in weight tossed 

 like corks along beach from 6 — 10 feet above ordinary high 

 water mark. Stones travelled along-shore for distances 

 aided by currents generated by heavy wave action. At 

 intervals of from ten to fifteen minutes a series of waves 

 much larger than others advanced far up the beach. It 

 was these rare waves which accomplished the whole of the 



1 For description of work done by waves on th-; ocean beaches in the 

 neighbourhood during this great storm, see N< tes on some Recent 

 Marine Erosion at Bondi, by C. A. Sussmilch. This Journal, 1912, p. 155. 



L— Oct. 2,1912.* 



