WAVES OF THE SEA 257 



reason, no doubt, is that the spring tides had 

 already begun to fill up the river. The camera 

 was placed upon the left bank, as low down as 

 was consistent with the safety of the instrument, 

 and about 30 feet back from the submerged 

 " Stonebench," so as to show the breaking of the 

 wave where the water suddenly shallows from 6 or 

 7 to i\ or 3 feet. A boat was engaged to meet the 

 bore, and was anchored in deeper water at a suit- 

 able distance ; and to obtain the scale a post near 

 the left bank was measured, its top being found 

 to be 58 inches above low water. 



The bore was heard at 9 a.m., a few seconds 

 before its appearance round the bend of the river, 

 at a distance of 513 yards from the camera. The 

 resurgings from the concave left bank had a fine 

 effect, well reproduced when the film is shown upon 

 the screen. The boat rode easily over the un- 

 broken wave in about 10 feet of water. The 

 height of the wave there I estimated at from 3 feet 

 to 3 feet 6 inches, and the height at the sides of 

 the river 4 to 5 feet. At the jetty or breakwater, 

 of which one post already referred to was visible 

 beyond the osiers, the bore suddenly sent a sheet 

 of water up to a height of 7 or 8 feet, but, re- 

 covering itself in a moment, the wave came on 

 with a front still smooth and unbroken, its inverted 



