792 



HANSEN 



[CHAP. 23 



Fig. 20. Tidal curves for Spring ( ), neap ( 



-.-.-.- line computed for M2 constituent. 



-) after observations in Heligoland. 



grid-point computed, |i has been plotted along the x-axis and observed ^1 

 along the y-axis. In Fig. 22 the same has been done with ^2- In both drawings 

 a correlation of observations and computations may be seen. Larger differences 

 are found in the Wash, a small bight on the English east coast where there is a 

 complicated depth pattern. Figs. 23 and 24 show the distribution of error for 

 ^1 and I2 respectively. The x-axis represents the difference between the ob- 

 served and computed values ; the y-a,xis represents the number of occasions 

 between integral numbers of cm/sec when these differences existed. In the case 



Fig. 21. Correlation between observed (vertical axis) and computed (horizontal axis) 

 elevation ^\ of the M2 constituent in the North Sea. 



