204' Mr. Robberds on the former Level of the Germaii Ocean^ 



or has it been gradually spread over them, below the usual 

 level of the waters that anciently covered their whole extent? 

 Mr. Taylor has appealed to the evidence given before the 

 Committee of the House of Commons to prove, " that the chief 

 portion of the eastern marshes is even now eighteen inches 

 to two feet below the surface of the rivers which pass through 

 them, and that the water is artificially kept out by embank- 

 ments and draining mills." Every one acquainted with tliis 

 district must be aware, that this is far too comprehensive an 

 assertion ; and I must regard it as a general inference, hastily 

 drawn from local and limited facts. That the circumstances 

 here described do partially exist along the course of the 

 rivers, pailicularly where they approach towards the sea, is 

 not denied ; yet the slight banks which have lieen thrown up, 

 must be looked upon in many instances rather as memorials 

 of past, than as proofs of existing danger; and seem to have 

 been more designed to guard the lands from the effects of un- 

 usually high tides, than to rescue extensive tracts, which with- 

 out the protection of such barriers would be constantly over- 

 flowed, to the depth of eighteen inches or two feet. But it is 

 certain, that for the space of several miles below the city of 

 Norwich, there is neither embankment nor draining mill, and 

 that the surface of the meadows is decidedly above the level 

 of the river. Within the memory of those now living, they have 

 advanced considerably in solidity, and the waters which in rainy 

 seasons used to stagnate upon them, are now quickly carried 

 away, without the assistance of artificial draining. The lowest 

 bed of their soil is sand, in which marine shells are found ; 

 above this, the sand is mixed with black mud, and the shells 

 that are distributed in it are both fluvial and marine : the ex- 

 ternal covering consists entirely of black mud, full of the re- 

 mains of aquatic plants, and abounding in freshwater shells. 

 In this series we may trace the successive operations by 

 which the bottom of the valley was filled : first, the sea exclu- 

 sively occupying the whole basin ; then, as its tides were gra- 

 dually withdrawn, the waters from inland springs, at first 

 mingling with them, next supplying their place, and finally, 

 settling into the contracted channel of the present river. 

 These are proofs, not of transient and irregular inundations, 

 but of the long residence and gradual retreat of deep waters. 

 It is far however from my object to contend, that no portion 

 whatever of the exterior surface of these valleys was produced 

 by the casual and temporary floods, by which they are known 

 to have been overspread even at no distant dates ; on the con- 

 trary, I shall show that these floods have been a natural an<l 



necessary 



