55 
» 
cation by the Danish antiquarians of the moss deposits, 
into (1) Boggy levels (Engmose), chiefly composed of, or at 
least with a substratum of peat, covered with water plants 
and grass, lying low at the bottom of valleys, and traversed by 
water courses ; these are generally less deep than the other 
deposits, say 5 to 12 feet thick. (2) Peat bogs (Lyngmose, 
Svampmose), large tracts composed of long-continued 
growths of Sphagnum and Hypnum, kept wet from below 
by concealed water supply, and usually covered more or less 
with heather or other vegetation. The lower portions of the 
moss consolidate into peat. They ordinarily measure from 
8 to 15 feet in depth; and (3) Forest moss pits (Skovmose). 
These are peculiar, and have proved the most interesting 
of such deposits. They occur in depressions in the surface 
of the glacial clays of the country, usually of small extent, 
but sometimes of considerable depth, down to 30ft. or more. 
They are distinguished by a marginal mass of tree stems, 
with branches and leaves. These trees are always found 
to have fallen in (towards the centre of the pit) and are often 
• so closely packed that it would seem difficult to place more 
of them in the space. When the pit is large enough to 
admit of it the central portion is filled up with moss, and 
forms a small peat bog, without or with the superficial 
growths. 
In places where time has allowed ground to consolidate 
and still later vegetation to find footing, the Danish pits 
arecommonly covered by successive growths of pine, then 
beech, then alder, and lastly hazel. 
M. Steenstrup has calculated that to complete the develop- 
ment of such a deposit, of say 10 to 20 feet in thickness of 
peat, some 4,000 years may be required; but the period is 
at present conjectural only. 
In the course of elaborate researches it has been ascer- 
tained that the Danish forest pits exhibit an earliest age of 
forests of pines (P. abies), a tree which is, except so far as 
