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hy others to the river Eotlier forming a succession of the bars, 

 it is highly probable that both influences are at Tvork bringing 

 about this result. Kivers loaded -n-ith the spoil of the land they 

 drain, if flowing into a lake or tideless sea, form a gradually 

 increasing delta, the suspended matter, being uniformly 

 deposited, depending upon the rate at -which the river flows. 

 The waters of some of the great rivers of the world discoloured 

 by sediment are traceable far out at sea. Colonel Sabine states 

 that the waters of the Amazon may in this manner be perceived 

 three hundred miles from land, entire deposition only taking- 

 place when the flow of the water ceases. In tidal rivers this 

 takes place on the levels becoming equal and the momentum of 

 the two streams of water balancing each other, when the mud 

 is deposited in a siu-prisingiy short space of time and a bar com- 

 mences to form. Advantage is taken of this fact to produce 

 the warp lands, as they are called, on the fens of the Trent 

 valley in North Lincolnshire, where the muddy water of the 

 river Trent is admitted by sluices over the adjacent lands, de- 

 position of the rich alluvial matter taking place a few minutes 

 after the gates are closed so as to allow the wa,ter to come to a 

 state of rest. This being one of the great but quiet operations 

 of Nature it is apt to be overlooked, and it is very j^robable 

 that it has played an important part in forming this addition to 

 the county of Kent. Elvers from their sources to the sea pass 

 thi'ough the varpng conditions of waterfalls, cataracts, and 

 rapids, to the more sluggish reaches of their lower coiu'se. 

 AVaterfalls cut their way back until they only exist as cataracts 

 or are reduced to rapids. Eaviues with steep sides are cut 

 through the harder rocks, whilst the softer strata yielding more 

 readily to the efi'ects of frost and rain form open valleys. The 

 upper and more rapidly flowing portion of a river deepens the 

 bottom of its channel, but the opposite eft'ect is produced in the 

 lower reaches where the slowl}' flowing water deposits sediment 

 on its bottom and on either side in overflowing, until the bed of 

 the river becomes raised to .such an extent that it is frequently 

 at a higher level than the surroimdiug country ; for example, 

 when sailing on parts of the Mississippi the adjacent land 

 appears much lower tlian the surface of the water. The vast 

 alluvial plain and delta of that river is computed to contain 

 30,000 square miles. (Lyell's Elements, page 22.) On a 

 smaller scale srmUar results have in like manner been brought 

 about in the vallej^ of the Stour. In the city of Canterbury, 

 ancient remains at a depth of eight feet show that a great 

 accumidation of soil has taken place. Our assistant- secretarj-, 

 Mr. James Fidlager, has in his possession some charred corn, 

 taken uj) from a cle^jth of eleven feet, in the High-street. "When 

 the Arundel tower of the Cathedral was rebuilt about 1825, it 



