equals half the product of energy and wave velocity, whereas in 

 a shallow-water wave it equals the product of energy and wave 

 velocity. 



DIRECTION OF PROGRESS 



Figure 2. Movement of water particles in a deep- 

 water wave of very small height. The circles show 

 the paths in which the water particles luove. The wave 

 profiles and the positions of a series of water parti- 

 cles are shown at two instants V\/hich are one quarter 

 of a period apart. The full-drawn, nearly vertical 

 lines indicate the relative positions of water pai - 

 tides which lie exactly on vertical lines when the 

 crest or the trough of the v^ave pass and the dashed 

 lines show the relative positions of the same particles 

 one quarter of a period later. 



Deep-vra.ter Waves of Moderate and Great Height 



By Weaves of moderate and great height are understood waves for 

 v/hich the ratio of height to length (H/L) is from l/lOO to 1/2 5 



