Estuarine Limits. 7 



II. -THAMES ESTUARY AND ITS 

 PHYSICAL FORMATION. 



ON casual thought the connection between the physical 

 formation of the Thames Estuary and its fisheries may not at 

 once seem quite apparent. But on further inquiry and reflec- 

 tion on the subject, their intimate relationship becomes more 

 manifest and appreciable. 



1. Limits. What are the precise limits of the Estuary? is 

 a question easier asked than answered. As a matter of fact, 

 there are no positive boundaries agreed on by authorities, and 

 the discrepancies of the latter only show that convenience of 

 purpose in view has been the sole guide. For instance, among 

 others, this has been acknowledged by such a sound authority 

 as Captain Tizard, B.N., in his extensive Hydrographical 

 Surveys in the " Triton," 1882-9.* 



He assumes and adopts as a western boundary a line 

 drawn from Southend across to Sheerness ; for an eastern line 

 of demarcation the meridian of the Kentish Knock Light- 

 vessel ; for the south, Kent [to N. Foreland] ; and for a 

 northern limit the coast of Essex. This area contains some 800 

 square nautical miles, and is crowded with sandbanks. Viewed 

 from a hydrographical standpoint, Tizard's eastern boundary 

 may be accepted ; but his western is merely an arbitrary or 

 nominal one, chosen possibly as including Sheerness and naval 

 interests. 



The Thames Conservancy's limit ( Crowstone to Yantlet) is 

 merely a formal divisionary line, serving to define sharply where 

 their and the Trinity Board's jurisdiction abut, irrespective of 

 estuarine demarcation. Notwithstanding it has a certain 

 historic importance, not only as concerns the ancient septennial 

 water pageants of the Corporation of the City of London, but 

 likewise as denoting the Isle of Grain's exemption from the 

 City's jurisdiction.f 



Summarised in his paper on "The Thames Estuary" [its channel changes], 

 "Nature," 1890. 



t Consult Fletcher, Jour. Statist. Soc., Vol. IV. (1841) " Ancient Prescriptive 

 Jurisdictions over the Thames possessed by the Corporation of London." 



