u 



*' Scattered all through them are flint knives, hatchets, and other instru- 

 ments of stone, horn, wood, and bone, with fragments of coarse pottery, 

 mixed with charcoal and cinders, but never any implements of bronze, still 

 less of iron." 



These, then, must have been collected before the period of the 

 growth of oaks on the borders of the peat bogs. The stone hatchets 

 and knives had been sharpened by rubbing, and in this respect are 

 one degree less rude than those of an older date, associated in France 

 with the bones of extinct mammalia. The mounds vary in height 

 from 3 to 10 feet, and in area some of them 1,000 feet long, and from 

 150 to 200 feet wide. 



By various observations it has been attempted to determine the age 

 of these mounds, and this is the question in which we, as students of 

 forest science, are chiefly interested. Lyell follows up the statement 

 of observations, by which it has been sought to determine that age, 

 with the remarks, 



"No traces of grain of any sort have hitherto been discerned, nor any other 

 indication that the ancient people had any knowledge of agriculture. The 

 only vegetable remains in the mounds are burnt pieces of wood and some 

 charred substance referred by Dr. Forchhammer to the Zostera marina, a 

 sea plant which was perhaps used in the production of salt. 



" What may be the antiquity of the earliest human remains preserved in the 

 Danish peat cannot be estimated in centuries with any approach to accuracy. 

 In the first place, in going back to the bronze age we already find ourselves 

 beyond the reach of history, or even of tradition. In the time of the Eomans 

 the Danish isles were covered, as now, with magnificent beech forests. No- 

 where in the world does this tree flourish more luxuriantly than in Denmark, 

 and eighteen centuries seem to have done little or nothing towards modifying 

 the character of the forest vegetation. Yet in the antecedent bronze period 

 there were no beech trees, or at most but a few stragglers, the country being 

 then covered with oak. In the age of stone, again, the Scotch fir prevailed, 

 and already there were human inhabitants in those old pine forests. How 

 many generations of each species of tree flourished in succession before the 

 pine was supplanted by the oak, and the oak by the beech, can be but vaguely 

 conjectured, but the minimum of time required for the formation of so much 

 peat must, according to the estimate of Steenstrup and other good authori- 

 ties, have amounted to at least 4,000 years; and there is nothing in the 

 observed rate of the growth of peat opposed to the conclusion that the 

 number of centuries may not have been four times as great, even though the 

 signs of man's existence have not yet been traced down to the lowest or 

 amorphous stratum. As to the 'shell-mounds,' they correspond in date to 

 the older portion of the peaty record, or to the earliest part of the age of 

 stone as known in Denmark." 



Thus far we have advanced with firm footing under us ; but here 

 we are stayed, as if a voice had called and said, " Thus far canst thou 

 go, but no further." Of what we have learned this is the sum. 



In reference to the trunks of Scotch fir found in some of the bogs of 

 Denmark, it is stated by Lyell, 



