354 Proceedings of the Royal Physical Society. 
some of these Pagan monuments are entirely buried and out 
of sight. 
I produce a stereoscopic photograph of the Callernish circle, 
which fortunately shows, by a difference in the depths of shade, 
the height to which the peat had grown around the stones ; 
two of them, to the left hand, were entirely covered. 
If, then, it is admitted that the stone circles of the Lewis 
were placed before, or only when the peat began to form, and 
that the peat has grown five feet since that time, it is evident 
that the least age of these monuments would be known if the 
annual increase of peat was known. But I am unacquainted 
with any data from which to form an estimate, and there is a 
wide difference in the opinions held on that point. One prac- 
tical gentleman assured me that the Lewis peat grew an inch 
every year ; at this rate the entire deposit might have taken 
place in about sixty years. Another estimate is nine inches 
in a century, but we require twice the number of years that 
this ratio would give to get back to Pagan times. As I am 
unacquainted with any class of facts that bears upon the sub- 
ject, it is not worth while to offer any conjecture at the present 
time. I may mention, however, that to my surprise, one of 
the Lewis bards has a tradition that at one time there was no 
peat in Lewis ; and it is also to be noted, that almost always, on 
excavating any of the Pictish dwellings, pieces of burnt stick 
(charcoal) are found at the fire-hearth. I do not wish it to be 
inferred, however, that there was no peat to be then found — 
only that sticks formed part, if not all, of the fuel then in use. 
A most instructive section was made a few years ago on the 
banks of the Creed, in the policies around Stornoway Castle. 
My notes are mislaid, but if my memory is correct, a cutting 
was made through a peat-bank to form a road, by which a 
perpendicular section of between eight and nine feet in height 
was exposed. About the middle of the bank, that is, three 
or four feet below the surface, was and is the place where a 
fire had been kindled; a few stones had been put round on which 
to stand the kettle, probably to boil a salmon, and bits of char- 
coal still remain in the ashes. The banks of the Creed could 
still supply enough indigenous birch to boil a craggan. 
Very erroneous opinions are abroad concerning the cause 
