288 On the Ancient and partly buried Forests qfHolderness. 



remains of a ridge of shelly gravel, which once extended 

 further to the south, and contracted the now broad estuary. 

 We may therefore easily admit that the aperture for the en- 

 trance of the tide has been augmented. It is also certain that 

 before the embankments the interior basins were very much, 

 nay, a hundred times, larger than those which now receive the 

 Humber flood. There are, perhaps, 300 square miles of sur- 

 face bordering the rivers which are below the level of the tide, 

 and therefore must at least in part have been flooded. It 

 might then very easily happen that the land-locked basin of 

 Wawn might be imperfectly drained, wholly free from marine 

 irruptions, and capable of supporting a forest of pines upon 

 earlier accumulations of drifted timber. 



10. There is another consideration of some importance in 

 discussions concerning the ancient levels of marshy and peaty 

 countries. The peat bed which occupied perhaps 3 or 6 

 feet in thickness while wet and spongy, will shrink to half or 

 one third the depth when drained ; and if loaded with sediment, 

 as in the process of warping, will be compressed to a few 

 inches. In some cases, therefore, the difference of levels as 

 now existing must be corrected by this rule to give the former 

 difference. 



In conclusion, it seems necessary to remark, that it is not 

 intended to convey the impression that this mode of explana- 

 tion will apply to every case of ' subterranean forests', nor that 

 it is actually applied by me to the whole area of the buried 

 forests of Yorkshire and Lincolnshire. I have here discussed 

 a particular case leading to some general reflections, but am 

 not in possession of data sufficiently minute and accurate for 

 a more, general investigation. Neither have I attempted to 

 fix the date of the accumulation of the peat, or of the growth 

 of the trees, relative to other geological monuments, further 

 than by showing that it is clearly subsequent to the dispersion 

 of the diluvium in Holderness, and therefore comparable to 

 the sera of the many lacustrine deposits which I have de- 

 scribed on the coast of Yorkshire. 



I feel it a duty to remind geologists of their obligation to 

 the late Dr. Alderson of Hull, for his early and valuable no- 

 tices of the timber and peat deposits of Yorkshire, and to ex- 

 press my thanks to Mr. Stichney, of Ridgmont, near Hedon, 

 who first drew my attention to the phaenomena which have 

 furnished the subject of this communication. 



