the results in their unsimplif led form are too iani\rieldy to be 

 of much practical value, (See appendix A.) 



Another Interesting treatment has been presented by Zeilon 

 (1911)» In this paper he stresses the Importance of the bottom 

 configuration in generating and maintaining oscillations in the 

 ocean. He discusses a model in which a uniform steady current 

 encounters an elevation in the bottom topography. He shows that 

 under these conditions a wave will, be generated downstream from 

 the elevation and, from, continuity considerations, will also ex- 

 tend upstream. The greatest in- 

 ternal wave amplitude will be in 

 the vicinity of the elevation. 

 Figure 11, taken from Zeilon 's 

 work, illustrates this effect, 

 Zeilon 's work is mentioned to sug- 

 gest that the bottom contours play 

 some part in the form.ation of in- 

 ternal Waves. It is therefore ad- 

 visable in any study of this phen- 

 omenon either to take this effect 

 into account or to eliminate it. 

 It was decided in this study to 

 utilize data taken in one locality 

 in order to eliminate bottom topog- 

 raphy effects. 



In discussing the tv;o-layer 

 system, mention should be made of a 



FIGURE II GENERATION OF INTERNAL 

 WAVES BY AN UNDERSEA 

 RIDGE. 



Diagram of series of six 

 photographs taken at in- 

 tervals of about one-half 

 second, shox-ring the gen- 

 eration of waves in the 

 boundary above the ridge 

 and their propagation on 

 both sides of it. To the 

 left of the ridge is vis- 

 ible a small pendulum in- 

 dicator, moving with the 

 water and showing the dir- 

 ection and intensity of 

 the current. 



36 



