346 



Scientific Intelligence. 



[NO. 10, NEW SEH1E8* 



surf and sand* until they are arrested by the approximating 

 Groynes, immediately around which, stationary deposits of sand 

 are thereby formed and accumulate, whilst the water by itself un- 

 checked continue to flow and pass on by the ends or heads of 

 these projectors (that is to be the lee side of them) where they 

 again stir up the sediment at the bottom and a reaction of all of 

 them together taking place, these conjoint movements occurring 

 in the manner, I have attempted to describe, cause, I conceive, 

 those indentations which are visible on the lee side of the 

 Groynes, but which is not the case on the weather side of them. 

 The Groynes running out as straight lines too from the Beach, in_ 

 stead of being curved, may also give a facility to the disturbing 

 causes above mentioned. How far to seaward these local actions 

 extend before meeting with opposition, I could not pretend to es- 

 timate, neither does it seem necessary at present to enquire. It 

 might, however, be supposed that at no great distance from the 

 shore there is no accumulation of Sand Banks ; on the contrary, 

 the sand shifts about as it is controlled by the elements above it. 

 It is hardly requisite to observe that the wind, current, tide and 

 surf all invariably run one way in these roads, that is in the paral- 

 lel where the shipping ride. 



8. It may not be irrelevant to ask the question how these im- 

 provements effect the shipping ? Years ago, it is said by the old- 

 est inhabitants that the Beach extended nearly as far out as where 

 the ships now ride (between which and the shore there was a 

 eocoanut tope) and as the sea encroached upon the land, so the 

 shipping anchored nearer. When the Groynes were commenced 

 and advanced, the Beach in proportion increased, thereby in some 

 degree affecting the safety of the inner anchorage, which does not 

 now allow room for a ship to wear should she cant wrong when 

 getting under weigh, but V essels can always shift their berths fur- 

 ther out as compelled by circumstances, and the new Port Regula- 

 tions now allow of their anchoring in one fathom deeper water, 

 without incurring extra Boat hire, that is to say nine fathoms. Here 

 I may mention that the ordinary declivity of the Beach was about 



* I also add tide because it is always under the influence of and ac- 

 companies the three forms except in calm weather when it fluxes and 

 refluxes East and West, or more correctly to and from shore. 



