125 feat in 2 years. It is possible, in fact probable, that this 

 bar is subjected to displacements which are much larger and more 

 rapid during the course of violent winter storms. At a point about 

 14.20 feet beyond the bar there is another which is less evident. 

 Within 300 feet of the water's edge there are found several bars, 

 which we will call interior bars, which move rapidly as is showi 

 on Figure 2. 



On Figure 1 there has been traced a line which I call the ''beach 

 profile supposed without bars.'' We will refer to this later. 



The interior bars have been studied in detail. They were measur" 

 daily whenever there was any reason to suppose that there had been an 

 appreciable displacement in the bar position. The velocity and 

 direction of the wind and the height and period of the wave also were 

 noted. Available parsonnel was not numerous and therefore no night 

 observations were made; which is unfortunate, for judging by the 

 noise of the sea at night the height of the waves on certain nights 

 was certainly much greater than the heights which had been noted 

 during the day. Up to a distance of 350 feet from shore the beach 

 profile was determined by leveling with the aid of a stadia board 

 and the heights given are probably correct within about 1 inch. 

 Farther seaward a sounding lead was- used to determine depths. The 

 positions of the soundings on the profile were determined by means 

 of a plane table. 



Previous research had led to six considerations which were to 

 be confirmed or modified by the observations made on the beach. 

 These considerations are: 



A. Bars form to the highest elevation at the breaking point of 

 the wave . At Karentes the exterior bars are formed and 

 displaced by the storm waves of winter. During calm 

 weather they are displaced only slightly, however the 

 interior bar is displaced by very small waves. 



B. After breaking the waves transport sand, and by consequence 

 the bars, toward the sea. 



G. Before breaking the waves transport sand, and by consequence 

 the b3.rs ; toward the beach. 



D. If one smooths the profiles of the bars observed on many 

 different occasions^ one will obtain a theoretical profile 

 which we have called "beach profile supposed without bars",, 

 It appears to be reasonable to assume that the bars are 

 accumulations of sand which are moved freely on the pro- 

 file; depending upon the action of the waves and as the 

 waves vary. Numerous experiments in the laboratory have 

 shown that there exists a. constant ratio between the 

 height of the crest of the bar above the "beach profile 



22 



