Correspondence — Rev. 0. Fisher. 283 



of the Wey and Mole ; part from the gorge through the Chiltern 

 Hills which flood Oxford and the soft Oolitic valleys. But for the 

 sea-shore, let Mr. Kinahan examine Romney Marsh, the Delta of the 

 Bother, formed by the wash down of the very highest part of 

 the Weald Hill, Crowborough Beacon, 800 feet high. At Hythe, 

 Dungeness, and Pevensey, he will find the flints with which he 

 would require " the whole area " of the Weald to be covered. But 

 from the top of Crowborough Beacon, the centre of the Weald, how 

 many hundred feet of Hastings sand, Weald clay, Greensands, Gault, 

 Chalk marl and flintless Lower Chalk have been washed away by 

 rain and rivers since the last speck of upper flint-bearing chalk 

 vanished ? The flints which remain " on the newer beds " of the 

 Weald (except those from the more recent denudation of the face of 

 the chalk slope) have been caught on the low flat soft valleys of the 

 Weald clay behind the hard gorges of the Greensand, and in the soft 

 valleys of the Gault behind the hard gorges of the Chalk. When the 

 beds of these gorges were lowered, the sides of the alluviums, no 

 longer overflowed, were denuded, and the alluviums cut back into 

 terraces. But their flat tops remain till the terraces are entirely 

 cleared away. The formation of these terraces has been always 

 going on at heights decreasing directly as the lowering of the beds 

 of the gorges and valleys. That it is going on now may be seen 

 from the deposit of new alluviums with drift gravel at the levels of 

 the present overflows of the rivers. The same thing may be 

 seen on the opposite side of the Greensand hard gorge below 

 Farnham, where the Wey runs into instead of out of the Weald, and 

 deposits vast quantities of drift gravel and alluvium in the soft 

 valley of the Gault. This, also, is going on now. Kivers are the 

 roads which gravels travel to the sea, though they may be arrested 

 for thousands, nay millions, of years in passing alluviums. Witness 

 the terraces of the Fraser Biver, etc., which are only gigantic effects 

 of what caused the Medway terraces. That is, throughout the wide 

 wide world, atmospheric disintegration and the erosion of rain form 

 a flat valley in the soft strata behind each harder stratum. Every 

 flood is then checked at the gorge of the hard stratum, and overflows 

 and deposits on the soft flat. When the bed of the hard gorge is 

 lowered, the bed in the soft valley behind is also lowered, and the 

 flooded river, instead of overflowing, cuts back its alluvium, which 

 remains as two terraces. Messrs. Foster and Topley mistake in 

 supposing (pp. 470, 471) that a rise of the land is necessary for the 

 deepening of the river-bed. It would only be necessary for those 

 parts of rivers whose beds are at the level of the sea. 



George Greenwood, Colonel. 

 Brookwood Park, Alresford. 



SUBMERGED FORESTS. 



Sir, — Submerged forests and the facts connected with them are 



important, as offering indications of the latest geological changes. 



Colonel Greenwood's theory, to which he recalls attention in your 



last Number, is an attempt to account for them without any sinking 



