28ft Dr Hibberts Observations on Vitrified Forts. 



understand how those who erected these works sot the mate- 

 rials necessary for their purpose.'''' 



After Mr Williams had thus got over the difficulty of arti- 

 ficial fusion, he promulgated his view, which, as he states with 

 much naivete in his preface addressed to Lord Karnes, appear- 

 ed so incredible that no booksellers of London would hazard 

 the publication of it. He supposed that the ancient inhabi- 

 tants of Scotland derived their earliest notion of vitrification, 

 " first, from melting bog ore, in the process of which they 

 learned how it would, if increased, vitrify stones and earth ; 

 secondly, from observations made while roasting oxen. It is 

 evident," adds this choice antiquary, " from the records of the 

 earliest antiquity, that it was the practice of almost all nations 

 to offer burnt sacrifices. And it was customary, on solemn 

 occasions, to burn a large-sized animal whole, which would re- 

 quire a very strong fire.'''' — " After they [the ancient inhabi- 

 tants of Scotland] became acquainted with this power of heat, 

 I suppose some genius among them to have employed it for 

 forming vitrified walls. The manner, however, in which he 

 employed it is still problematical. I have tried the subject se- 

 veral ways in my own mind, but find difficulty in all the me- 

 thods I have yet imagined. I shall, however, mention that which 

 satisfies myself the best, and which appears most practicable. 

 I imagine they raised two mounds of earth parallel, and in the 

 direction of their intended wall ; and that they filled the ground 

 formed by these parallel mounds with fuel, above which they 

 laid the materials to be vitrified. There is no doubt but a 

 strong fire would fuse these stones, especially if they were of 

 the plum-pudding kind, and not too large ; and the frame of 

 earth would prevent them, when in fusion, from exceeding anv 

 assigned breadth. I suppose they added layers of fresh fuel 

 and materials alternately, and raised the mounds of earth till 

 the whole was brought to the intended height. I am confident, 

 from the appearance of the ruins, that the materials of them 

 were run down by the fire in some such method as this. For 

 in all the sections which I have seen, whether of the larger or 

 of the smaller fragments of these ruins, I never observed the 

 least appearance of a stone being laid in any particular way. 



