against the German Ocean on the Norfolk a?id Suffolk coast. 303 



a collateral proof of the permanent level of this sea ; and the 

 circumstances of the salinse will not, on examination, be found 

 to strengthen the contrary opinion so much as was antici- 

 pated. Without dwelling further on this head, it only remains 

 to be noticed, that some caution is to be observed in deter- 

 mining their real localities ; because the boundaries of several 

 parishes, enumerated in that ancient document, not only fre- 

 quently stretch to a remote distance from the villages to which 

 they appertain, but it is of common occurrence in this district 

 that detached portions belong to parishes that are situated 

 many miles in the interior. The level tract of marshes be- 

 tween the Yare and the Waveney, opposite Reedham and ex- 

 tending to Breydon Water, contains no less than nine instances 

 of this intermixture, some of which are detached eight miles 

 from the main parts of their parishes. Local knowledge, in in- 

 quiries of this kind, is often desirable, to explain many circum- 

 stances otherwise obscure, and irreconcileable with probability. 

 Respecting the hypothesis of the general subsidence of the 

 German Ocean, I offer no other opinions than may be inferred 

 from the review of the facts which are intimately connected 

 with this investigation ; and from a previous remark that *' if 

 any alteration could be perceptible over so extensive an area, 

 it would be an elevation, corresponding with the disintegra- 

 tion of the land." I was not then aware of a paper which was 

 read before the Geological Society of London in 1816; before 

 the Wernerian Society of Edinburgh in 1820, and published the 

 same year in the Edin. Phil. Journ., entitled " Observations on 

 the Bed of the German Ocean or North Sea, by Robert Steven- 

 son, Esq. Civil Engineer*." This treatise is announced as the 

 result of much personal observation, and considerable pro- 

 fessional experience of the eastern coast of Great Britain. Its 

 object is to prove " a great change" in the level of the Ger- 

 man Ocean; not that it has fallen, conformably with the views 

 of Mr. Robberds, but that it has mra, and continues slowly 

 to rise. The cause is traced to the elevation of the bed of that 

 ocean, by means of the vast increase of alluvium, the wearino- 

 away of cliffs and headlands, the reduction of high grounds^ 

 the debris of mountains, the decay of vegetable and other or- 

 ganic substances, and the mud of rivers. Mr. Stevenson has 

 founded his reasoning on the consideration of a long series of 

 observations ; but it would be unfair to institute any compari- 

 son of his hypothesis with that of Mr. Robberds, as the data 

 which have influenced the opinion of diat genUeman are not 

 helbrc us. The circumstance is chiefly in'troduced to show 

 to what opposite conclusions the ablest advocates of truth, sci- 



• Edinb, Phil. Journ. vol. iii. art. V. 



ence, 



