Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/266

256 in that country but by a very distant land carriage, or a very circuitous route by sea. It is evident that a commercial system of some sort must have been established before the inhabitants of these countries could have cemented their buildings with lime, however they might have been acquainted with its properties. It is equally a matter beyond the power of modern investigation to discover whether they were the works of the aboriginal Caledonians or of their Danish invaders. Neither analogy nor examination of the remains throws the least light on the subject, a subject which as it is beyond the reach of historical or traditional evidence, seems equally divested of all those circumstances from which truth is sometimes elicited. It is nevertheless a general opinion that they are remains of the earliest works of ancient inhabitants. This too is a proposition which appears to rest on a very vague sort of reasoning. The same Antiquaries suppose that the well known circular Pictish towers were built before the use of iron, but admit that they are of more modern date than the vitrified forts, from the greater artifice apparent in them. It will however be clear to any one who shall examine the vitrified fort near Amwoth in Galloway, that the ditch which has been excavated for the purpose of giving the fort a scarp all round, has been cut down by iron, or at least by a tool of metal. It is from the greater accumulation of soil on the ruins of the vitrified walls, an accumulation often sufficient to conceal them entirely from the view, that we are (if from any thing) entitled to consider them as erections of a date more ancient than the towers of Glen Elg or Dun Dornadilla, or than any of the works as yet examined in which unvitrified masonry has been used. But it is superfluous to pursue these archæological difficulties further.

The question on which the two contending parties have been most at issue, was, whether the vitrification was the result of design