FOR GREA T BRITAIN AND IRELAND. 53 



LEVEL ASSUMED BY MUD A MEASURE OF 

 EXPOSURE. 



" I have elsewhere referred," observes Mr. S. (Proceedings 

 Royal Soc., Edin., vol. iv., p. 20x3) " to another feature which 

 will be found of very considerable value in judging of the 

 exposure of a coast. This is the level below the surface of 

 tfie low water, at which mud reposes" 



" It may appear unlikely that the disturbance of the 

 surface of the sea occasioned by storms should be propa- 

 gated to great depths, but there is no want of evidence on 

 this head. After easterly gales I have repeatedly seen 

 rounded pieces of coal, containing nearly a cubic foot, thrown 

 up on the beach of the Firth of Forth, near Newhaven. 

 Indeed, the fishing population of the adjoining village 

 are in the habit of turning out in search of fuel after every 

 heavy gale. Mr. John Murray states that in the coal trade 

 (of Sunderland) the ballast of the vessels returning to the 

 north, which sometimes consisted of chalk and flints, was 

 usually discharged at a distance of from seven to ten miles 

 from port, instead of five miles as formerly ; yet after a 

 violent storm the whole coast was strewed with ballast, 

 which had been cast into water ten fathoms at least in 

 depth, and the flints were easily recognised as coming from 

 the Thames (Inst. of Civil. Eng. Trans., vol. xix., p. 670)." 



" Mr. (now Sir) J. Coode found from under water 

 examinations made with the diving dress, that the shingle 

 of the Chesil Bank, near Portland, was moved during heavy 

 winter storms, at a depth of eight fathoms. Mr. E. R. 

 Calver, R.X., states that he has seen waves six or eight 

 feet high change their colour from the abrasion of the 

 bottom, after passing into water of seven or eight fathoms. 

 From these statements it may easily be inferred that in 



