778 



[chap. 23 



authors give only co-tidal lines. In marginal and adjacent seas of smaller area, 

 co-tidal and co-range lines have been drawn for all principal tidal constituents. 

 Defant (1957) published a list of most of the tidal charts constructed for the 

 sea. Those best known by observation are the tides in the North Sea, in the 



100 



Fig. 9. Co-tidal and co-range lines for constituent M2. Numbers on the full lines give the 

 time of high water after the moon's transit of Greenwich. The numbers on the broken 

 lines give the range in metres. (After Hansen, 1956.) 



English Channel and in the Irish Sea. For these areas co-range and co-tidal 

 charts have been drawn. Charts with constant ^1 and ^2 for the North Sea are 

 given in Figs. 7 and 8. The tides in the Mediterranean, especially in the Adriatic, 

 in the Red Sea, Persian Gulf and Gulf of Mexico and in the Baltic and a number 

 of marginal seas in the Indian and Pacific Oceans had been investigated. 



