ON TUB RATE OF EROSION OF THE SEA-COASTS. 



239 



[TUAM,. 



t, and 



J. N. 



ofessor 



,ASTON, 



for the 

 -coasts 

 bstrac- 

 , up hy 



itigation 

 arcnt to 

 progress 

 success- 

 30se and 



members 

 }t in the 



jf haman 

 jquainted 

 to. The 

 ■ England 

 .ritiea not 

 ,s known, 

 pon many 

 ■y for the 



Sometimes the decrease of shinglo is dno to a quantity being taken 

 away from the beach for ballast, building, road-making, or other purposes. 



Solid rocks, or numerous large boulders, occurring between tide-marks, 

 are also important protectors of the coast- line. In some cases these have 

 been removed, and the waves have thus obtained a greater power over 

 the land. 



To investigate these various points is the main object of the Committee. 



A large amount of information is already in hand, much of which ha& 

 been supplied by ^Ir. J. B. Redman, who for many years has devoted 

 special attention to this subject. Mr. R. B. Grantham has also made 

 important contributions respecting parts of the south-eastern coasts. 



But this information necessarily consists largely of local details, and 

 it has been thought better to defer the publication of this for another 

 year. Meanwhile the information referring to special districts will be 

 made more complete, and general deductions may be more safely made. 



As far as possible the information obtained will be recorded upon the 

 six-inch maps of the Ordnance Survey. These give with great accuracy 

 the condition of the coast, and the position of every groyne, at the time 

 when the survey was made. 



Appended is a copy of the questions circulated. The Committee will 

 be glad of assistance, from those whose local knowledge enables them to 

 answer the questions, respecting any part of the coast-lino of England and 

 Wales. 



Copies of the forms for answering the questions can be had on 

 application to the Secretai'ies. 



Ajjpendu' — Copy of Questions, 



1. Wliat part of the Eiiglif^h or Welsh 

 Coast do you know well ? 



L'. AVliat is the nature of that coast ? 

 («) If cliffy, of what are the cliffs 



composed ? 

 (/y) What are the heights of the 



ciitf above H.W.il. ! 

 Greatest ; average ; least. 



ii. What is the direction of the coast- 

 line? 



4. What is the prevailing wind ? 



5. What wind is the most important — 



(«) In raising high waves ? 

 (J) In piling up shinglo ? 

 ((■) In the travelling of sliingle / 

 G. What is the set of the tidal currents .' 



7. What is the range of tide ? 



Vertical in feet. \Vidth in yards 

 between high and low water. 

 At Spring tide ; at Neap tide ? 



8. Does the area covered by the tide 



consist of bare rock, shingle, sand, 

 or mud ? 



9. If of shingle, state — 



(a) Its mean and greatest breadth. 



(&) Its distribution with respect to 

 tide-mark. 



(f) The direction in which it travels. 



{d) The greatest size of the pebbles. 



((') Whether the shingle forms one 

 continuous slope, or whether 

 there is a * spring full ' and 

 'neap full.' If the latter, state 

 their heights above the respec- 

 tive tide-marks. 



10. Is the shingle accumulating 

 diminishing, and at what rate 1 



or 



■■.'2 



11, If diminishing, is this due partly or 

 entirely to artificial abstraction 1 

 iSee No. 13.) 



If groynes are emploj-ed to arrest the 

 travel of the shingle, state- - 

 (a) Their direction with respect 

 to the shore-line at that point, 

 (ft) Their length. 

 (r) Their distance apart. 



