On the Pagan Monuments of the Outer Hebrides. 355 
and growth of peat ; in most books I see the observations of a 
certain Lord Cromarty are quoted, from which it is most illo- 
gically inferred that all peat is the result of the decay of forest 
trees. So wide spread is this allusion, that it has been quoted 
to me where the peat-banks were visibly and presently telling 
their own history. Without denying that the decay of forest 
trees in marshy ground will form peat, it requires only the 
most superficial observation to know that wood peat occurs 
only in the most homoeopathic quantity in, at any rate, the 
islands of North Britain. It fortunately does occur as an 
exceptional instance, and then in so marked a manner as to 
leave no chance of confounding wood peat with the almost 
universal moor peat. The bulk of the peat of the northern 
and western islands is made up of the roots of rushes and 
moor-grass ; the mosses help to keep it constantly wet, and 
the tormentilla (and probably other plants) supplies tan to the 
moss, and prevents it from decomposing into vegetable earth. 
Such were the conditions when the peat first began to grow, 
and such they still continue. I have looked over thousands 
of sections of peat banks in which there was no difference in 
the composition of the peat, from the base where grew the first 
peat-forming plants to the surface at the present moment, 
excepting consolidation towards the bottom from time and 
pressure. When the surface of a peat bank has been exposed 
for some time to wind and rain, the most solid, as well as the 
spongier portions of the peat will be found disintegrating into 
laminae, which laminse probably represent the annual growth, 
and if they were distinct enough to be counted would indicate 
the age of the peat. From whatever cause, there was a time 
when the general surface of the country was bare and lifeless, 
which was followed by a growth of plants, in no way differing 
from those that are now struggling for existence upon the 
moor. And from what has been said before, it would seem 
that man made his advent here at much about the same 
geologic time. 
A common tradition of the Lewis is, that the ground was 
once entirely covered with forest trees, and that the wood was 
burnt down by the Northmen to deprive the aborigines of the 
shelter that it afforded. In almost all traditions there is 
