1863.] NORFOLK BOTANY. 435 



how the ancient sandbanks which now constitute the elevated 

 portions of Norfolk have been accumulated. 



The drainage of these eastern feus is effected by windmills — 

 not mills, but pumps, worked by the wind. These raise the water 

 from the ditches, and it is conveyed over the bank into the 

 stream or river, which is considerably higher than the level of 

 these flat or depressed tracts. The drainage by sluices, as in 

 Kent, is impracticable, because the land is not yet elevated 

 above the level of the sea at low water, i. e. when it is ebb-flood. 



Supposing that the sea will retain its present level, — a very 

 probable assumption, — a time will come when the Norfolk fens 

 may be drained as the Kentish fens are now ; and at this time, 

 which may not come till many ages have passed away, the latter 

 may have so far been elevated by the silent, though constant, in- 

 crease of soil, as to be drainable without any mechanical con- 

 trivance whatever — merely the force of gravitation, the necessity 

 of the water's flowing towards the lower level, i. e. the sea. 



The conservators of the Norfolk rivers doubtless prohibit the 

 use of steam as a motive or propelling power. Tlie ripple pro- 

 duced by the agitation of the water, and the rapid passage of 

 vessels through these narrow, though navigable rivers, would 

 wear away the banks, and the preservation of the whole country 

 would be endangered. 



Numerous trows, of no very great burden, daily navigate these 

 three rivers — the Bare, the Yare, and the Waveney. These are 

 never tracked, or drawn by horses, as on the Thames, Avon, and 

 other more southern rivers, but are dependent solely on the wind. 

 They are occasionally becalmed, and at bends of the stream they 

 must move their craft by the slow process of pushing them past 

 the bend by long poles. As the rivers are all far above-ground, 

 and the breezes are never impeded by trees and buildings, the 

 trows get the full benefit of it. The use of steam power would 

 facilitate navigation, but it would risk the safety of the banks, 

 which protect the whole country from the calamitous effects of 

 such an inundation as that with which the fens about Lynn and 

 Wisbeach have been so recently visited. 



