76 
GRANITE LEVEL. 
a htap ot dark wood^ and on examining tlie 
pit he will see a layer of leaves and woody 
matter upon the tin gravel. The history 
of these deposits has been fully investigated: 
a common section is ( 1 ) the surface mass 
of peat, ( 2 ) a bed of gravel, ( 3) a layer 
of river sand with trees, the remains of 
red deer, and the works of man, (4 ) another 
bed of sand, and then of mud, with hazel 
nuts, wood, and moss; and below this, the 
roots of trees amidst the granite and tin 
pebbles which lie on the rocky floor. There 
are usually two layers of vegetable matter, 
but only one of roots. The remains of 
animals and the works of man are found in 
both, but the latter do not conclusively prove 
that man inhabited these once sylvan shades, 
as they may be due to the works of ancient 
miners. The trees are such as grow in 
lower valleys of the same districts at present. 
Ireland abounds in bog timber, which is 
there clearly associated with the Elk, and 
with traces of man’s occupation. In the 
Penny Cyclopedia we read that in June, 1833, 
an antient wooden house was discovered in 
Drumkelin bog, in the parish of Invernon, 
