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 



