68 IMPROVED FISHERY HARBOUR ACCOMMODATION 



of the main body of the tide approaches to coincidence with 

 the direction of the heaviest swell, and they are probably 

 worst at headlands on which the tide splits. 



" 3. At parts of the coast where strong tide-currents set 

 off the shore they reduce the waves by acting as a break- 

 water. 



" 4. Where a considerable part of the coast retires, there 

 will be less sea during the strength of the tide, even though 

 the waves come in parallel to the shore, because the tide 

 keeps outside, following the general direction of the trend of 

 the coast. But this will probably not hold good of small 

 re-entrant hollows of the shore. 



" 5. Although the line of exposure and the tide-current 

 are parallel to the coast, yet if the tide runs in a line very 

 near the shore, as is the case in short narrow channels where 

 the velocity of the current is increased, there may, neverthe- 

 less, be a very heavy sea. 



" 6. The most severely tried shores will be those where 

 the line of maximum exposure is at right angles to the line 

 of shore, and where it coincides with the direction of the 

 principal tide-current." 



RELATION BETWEEN HEIGHT OF WAVES AND 

 DEPTH OF WATER. 



"Another circumstance affecting the exposure of any 

 marine work is the depth of the sea or ocean on the shores 

 of which it is built." 



" The great rolling billows so commonly met with in the 

 Atlantic Ocean cannot be generated in the shallower parts 

 of the German Ocean, unless, perhaps, in such peculiar 

 circumstances as have just been adverted to." 



" I advise the reader when judging of any locality not to 



