ALLUVIUM. RECENT FOUMAT1ONS. 771 



-in particular localities. This is observable in the neighbourhood of lakes, upon which the 

 peat gains, altering their limits a process which may be remarked at the upper end of 

 Dervvent water, and around all the small mountain lakes of Wales, the completion of which 

 appears in many of the Irish bogs, which were once lakes, in process of time conquered 

 by the vegetable formations, and supplanted by spongy carbonaceous masses. 



Subterranean forests, consisting of branches of trees, trunks uprooted or broken off, 

 the roots retaining their natural position a proof that the trees grew upon the spot 

 'are almost universally associated with peat wherever they occur, the soil of which now 

 forms their sepulchre, though peat itself is found abundantly apart altogether from fallen 

 timber. Upon the drainage of a low-lying forest being interrupted, the conversion of the 

 site into a swamp would speedily follow, destroying the trees ; and upon their prostration 

 by the winds through the process of natural decay, or the hold of the trunks upon the soil 

 being loosened, the entombment of the whole beneath peaty matter produced by vegetable 

 accumulations would commence. In this way we may explain the occurrence of many 

 of those subterranean forests that are found; though in several parts of northern 

 Europe, and especially in Great Britain, man appears to have been the agent in felling 

 these forests, whose prostration acting as a dam to the surface waters, prevented their 

 running off, produced morasses, the growth and decay of aquatic plants finally covering 

 up the timber. Unable to contend with the arms and discipline of the Roman legions in 

 pitched battles or in the open country, the ancient Britons took shelter in their woods, 

 from which they annoyed the invaders by frequent incursions. It was the policy there*- 

 fore of the Roman generals to deprive the native inhabitants of these places of retreat by 

 cutting down the forests, in which they not only employed their own troops, but the tribes 

 previously subjugated. Hence Galgacus, in his speech before the battle with Agricola, 

 warned his countrymen that these servile labours awaited them amid stripes and indig- 

 nities should they be conquered. Such difficulties attended this plan of subjugation, with 

 the building of his celebrated wall, and the construction of other works, that the emperor 

 Severus is said to have lost fifty thousand men, though his army never met the Britons in 

 the field. In particular the low level country of south Yorkshire and north Lincoln, is 

 mentioned as an ancient primeval forest, which the invaders, taking advantage of a strong 

 south-west wind, are supposed to have set on fire in various places, the pines readily 

 burning, the unconsumed trees being felled with the axe. Hence in this locality, which 

 continued for centuries an extensive swamp, a subterranean forest was discovered upon 

 the draining of Hatfield Chase. From a valuable description of this operation and its 

 singular revelations, drawn up by the Rev. A. de la Pryme, in the year 1701, the 

 annexed particulars are gleaned : 



The famous levels of Hatfield Chase in Yorkshire constituted the largest chase of red 

 deer in England belonging to Charles I., containing in all above 180,000 acres of land, 

 about half of which was yearly drowned by vast quantities of water. This being sold to 

 Sir Cornelius Vermuiden, a Dutchman, he at length effectually dischased, drained, and 

 reduced it to arable and pasture ground, at the immense cost of 400,000/. The soil of 

 most of this marsh land, all round to the highlands of Lincolnshire and Yorkshire, has 

 yielded vast multitudes of the roots and trunks of trees of all sizes, and of most of the 

 sorts that our island either formerly produced, or does at present pines, oaks, birch, 

 beech, yew, thorn, willow, and ash the roots of the greater part standing in the soil in 

 their natural position, and the trunks lying by their proper roots. The smaller trees are 

 found in all directions, but the larger ones commonly north-east. A third part of the . 

 trees were of the fir tribe, some thirty yards long and more, and in such condition as to 

 be sold for the masts and keels of ships. Oaks, black as ebony, abounded, capable of 

 being used ; and ash trees were the only ones found decayed. Many of the trees, espe- 



3 D 2 



