WA VES. 35 



break upon the south and south-west side of these Atlantic islands, 

 and as gales proceeded northward the sea was seen breaking on the 

 northern reefs. 



" I apprehend that the great undulations raised by the wind in 

 revolving storms are raised along the radii of the whirlwind circle, 

 and roll straight onwards in the direction of tangents to the circle of 

 the whirlwind. " 



The foregoing record seems to be of special value on account 

 of the observations having been made from an island so far 

 removed from the mainland that the direction of the swell would 

 not be influenced by it. 



Height of Waves. There seems to be a general tendency to 

 over-estimate the height of waves, and statements on the subject, 

 to which credence can scarcely be given, are frequently made. 



It was stated by Lord Dunraven that breaking waves on the 

 south-west coast of Ireland had been known to attain a height 

 of 150 feet. 1 



Captain Sir E. Belcher, C.B., records having encountered 

 waves 90 feet in height, trough to crest, while crossing the Gulf 

 Stream in H.M.S. Bellerophon, during a voyage from Newfound- 

 land to England. 2 



Waves are reported to have been often seen in the south 

 bay of Peterhead, N.B., which obscured the Buchan-Ness 

 lighthouse from the view of an observer stationed on the quay 

 of the old harbour. 3 This, under the conditions which are 

 specified, would have necessitated the waves being from 90 to 

 100 feet high, trough to crest ; but there must have been a 

 mistake in this instance, because the soundings along the line of 

 sight are such that no waves approaching such a height could 

 possibly exist. 



It is probable that during storms the height of spray or 

 broken water is often estimated, instead of that of the actual 

 wave, and that the grandeur of the scene is conducive to exag- 

 gerated ideas being formed. 



I believe it may be safely assumed that the greatest height 

 of storm-waves, trough to crest, does not exceed 50 feet, except- 

 ing, perhaps, about the region of Cape Horn, where, from 



1 Rankine, "Civil Engineering," p. 756. 



2 "Report of Select Committee on Breakwaters and Harbours, 1860," p. 54. 

 * "Report of Committee on Employment of Convicts, 1884," p. 49. 



