258 WAVES OF THE SEA 



image perfectly mirrored by the smooth water 

 ahead of it. Then, on reaching the hidden Stone- 

 bench, the wave curled over in a beautiful scroll. 

 But no stationary photograph can reproduce the 

 effect which is given on the screen as the dark- 

 fronted curling wave rushes out of the picture, which 

 is then immediately flooded with light, the bright 

 clouds instead of muddy banks being now reflected 

 by the smoother waters. The speed of the bore 

 was about 13^ statute miles per hour. The ex- 

 posure of film was continued after the bore had 

 passed in order to illustrate the after-rush of water, 

 the speed of which was well shown by floating 

 debris. A boat happened to come by, one of the 

 occupants of which was gathering flotsam and 

 jetsam, and the camera was then revolved so as 

 to follow the boat as it passed. Owing to high 

 osiers intercepting the view up-stream, it was not 

 practical to cinematograph the bore from behind, 

 as had been intended. High water occurred 56 

 minutes after the passage of the bore, the total 

 rise being 8 feet 6J inches. The height of the 

 water then above ordnance datum was several feet 

 higher than high water of even a 40 -foot tide at 

 Portishead. The current continued to flow up the 

 river for 31 minutes after high water. 



The tidal bore in nature is not precisely repeated 



