Mr. R. C. Taylor on the Geology of East NoifolL 429 



higher elevation than the open sea whence they proceed. On 

 the contrary, in narrow entrances, like the haven of Yar- 

 mouth, the tidal waters speedily sustain a material decrease 

 in their height ; and in this instance, we have seen that the 

 level of Lake Breydon is from one to three feet lower than 

 the ocean, from which it is separated by an alluvial bank 

 not lialf a mile across. If to the thickness of the bed of ooze 

 be added the difference between its present surface and that 

 of the sea at high tides, we obtain the absolute depth of water 

 which could with any probability be contained witiiin the ees- 

 tuaries, at the earliest period, before they received any portion 

 of their covering of marine sediment. But there appear no 

 conclusive reasons for assigning a higher level than four or 

 five feet above the mean height of the existing rivers, at any 

 period of which we possess historical records. 



Surely Mr. Robberds's etymology of Herringby and Her- 

 ringfleet is explained to favour a given theory, and must be 

 received with caution. One at least is an evident corruption 

 of compound Anglo-Saxon words, and has no reference to 

 fish, whose habits lead them to avoid shallow muddy rivers. 

 In Domesday Book, Herringby is written Har-ing-bei. Her- 

 ringHeet is spelt Herl-yng-Jlete ; and in a subsequent record 

 we have it Herl-inga-jlet : the two first syllables being clearly 

 the same as Herling, lately written Harlmg, in Shrophani 

 hundred. 



About the year 901 the boundaries of the counties and hun- 

 dreds were defined, and the limits of parishes and manorial 

 jurisdictions were determined. These provincial subdivisions, 

 and even the estates into which they were further appropri- 

 ated, are carefully registered in Domesday Book. It happens, 

 without any exception, that all the boundaries of the counties, 

 hundreds, and local jurisdictions of this district, are the rivers 

 which whid through the various marsh}' valleys. It follows, 

 therefore, that these streams had, as early as the year 900, 

 formed themselves channels, adapted to mark the boundaries 

 of property; which channels have continued to our times, 

 with little alteration, except at their immediate outlets. 



They were gradually embanked, as cultivation proceeded 

 and the value of land increased. We know that the river 

 which divides the hundreds of Flegg and Hajiping was em- 

 banked previously to 1274', near the Abbey of Holm; for in 

 that year occurred a dispute about the right of fishing from 

 the river's banks. 



One mode of estimating the comparative elevation of the 

 waters, is distinctly furnished in the causeways or dams, which 

 were early conbtruclcd across the ocstuarics. The bridge call- 



cd 



