Central Scotland, it is quite likely that one or more may be found in that island. And all these vitrified forts are so many "glass castles". Not "glass" as we now conventionally understand the word, but glass in its cruder form. Thus, the fairy tales which tell of kings or giants dwelling in castles surrounded by walls of glass may be historically true, in so far as concerns the materials of the castle walls. Of course, when a tale has outlived by many centuries the circumstances in which it originated, the truth which it embodies may become gradually enshrouded with error. And in such a case as this one can see how the tale, long surviving the use of vitrified castles—whose very existence became forgotten—would by degrees take on the appearance of impossibility. The walls of an impregnable castle could never have been formed of glass, as that word is understood by modern people; and, owing to this misinterpretation of a word, the modern reciter of the tale and the modern artist, yielding to their own imagination, conspire to render the whole story utterly incredible, as they believe it to be.
Now this solution of the "glass castle" of tradition—which I, at least, am ready to recognise as not only quite reasonable but also probably correct—represents a method which is capable of wide application. That these traditions of the common people are baseless nonsense I do not believe. Sir Walter Scott, by the mouth of his Mrs. Bethune Baliol, makes a remark in this connection which is well worth considering, although it cannot be held to have any direct application to any serious student of folk-lore. "I profess to you," says Mrs. Baliol, in response to the arguments urged by her kinsman in support of the authenticity of tradition, "I profess to you that I am very willing to be converted to your faith. We talk of a credulous vulgar, without always recollecting that there is a vulgar incredulity, which, in historical matters, as well as in those of religion, finds it easier to doubt than to examine, and endeavours to assume the credit of an esprit fort by denying whatever happens to be a little beyond the very limited comprehension of the sceptic." Thus (to apply Mrs. Baliol's dictum to the case just cited), a man of this kind, ignorant of the existence of vitrified forts, will at once dismiss the "glass castles" of tradition as utter nonsense. Whereas a student of tradition, such as Lady Ferguson, will endeavour to find—as in this instance she has
