VITRIFIED FORTS is a name that has been given to certain remarkable atone enclosures existing In parts of Scotland, which appear to have been subjected to the action of fire. Attention was first collect to the subject by Mr. John Williams, a civil engineer of the last century, who had examined some of them while conducting certain mining operations in the highlands under the orders of the Board of Annexed (or Forfeited) Estates In 1773, and who, in 1777, published a disquisition about them, under the title of 'An Account of some re markable antient Ruins lately discovered In the Highlands and Northern Parts of Sootiand : In a Series of [13) Letters to 0. 0. 31., Esq.' five. Edinburgh. Williams gave these piles the name of vitrified forte, unhesitatingly assuming that they were artificial structures.
Nevertheless the idea, that the so-called forts were of volcanic origin, which had been previously held by Scottish writers, was soon after started anew by Pennant, who hall seen one of them, and was taken up by other speculators; In particular It was attempted to be established by the lion. Dairies Barrington, In a paper read before the Society of Antiquaries in 1781, and published In the sixth volume of the ' Archreo logia ' the following year. But this notion may be said to be now given up on all hands. The subject has also been discussed by Dr. James .Anderson and other writers In the' Archteologia.' the ' Memoirs of the Wernerian Society,' the ' Transactions of the Royal Society of Scot land,' the ' Statistical Account of Scotland,' and of late years at some length by Dr. John Macculloch in the' Transaction); of the Geological Society of London,' and in his ' Highlands and Western Isles of Scot land ; by Dr. ti ibbert, as the result of a series of inquiries set on foot by the Society of Scottish Antiquaries, and published in the fourth volume of their ' Transactions,' and by Mr. D. Wilson, in his Areffieo logy of Scotland.' The original description of the general nature of the vitrified forte given by Williams has not been corrected or contradicted in any material point by subsequent observers. And his views were supported at the time, on cheinieel and other considerations, by Dr. Black, and also by James Watt, who (apparently before the subject had attracted the attention of Williams) had personally' and carefully examined the AIM fort (that on the hill of Craig Phaulrick, or Craig Patrick, near Inverness) which Pennant had hastily inspected. A description of this
fort by Watt and a latter from Black are subjoined to Williams's account.
Every vitrified fort Williams lied seen was situated on the top of a small hill, overlooking and commanding a surrounding valley or plain. always having at the summit a level area of greater or bees extent, mid for the most part inaccessible or very steep, at least on one side. Indeed, he asserts that the hills are always difficult of access, except in one pLatio, which has everywhere been strengthened by additional works, of which lie gives a description. What is called the fort consists of a wall enclosing tho level summit, generally, in part at least, rectili neal and rectangular, but sometimes having one or more of the sides curved to suit the shape of the area. Exterior to this is sometimes a second eirounivallation, which in some instances approaches within a few yards of the first, in others is removed from It to a considerable distance; but this outer enclosure is merely oonstructod of loose blocks of stone; it is the inner wall only which is entirely or partially vitrified. Williams's account is, that the materials have been " run and compacted together by the force of fire ; and that ao effectually, that most of the stones have been melted down ; and any part of the atones not quite run to glass has beau entirely enveloped by the vitrified matter ; and in some places the vitrification has been so oomplete, that tho ruins appear now like vast masses or fragments of coarse glass or slags." Generally, however, it would appear that the vitrification is not so complete as this description would seem to imply, though it may be sufficiently applicable to the more perfect specimens : in many cases the fire has only given the wall a coating of glass ; in some, only one side of the wall is vitrified. The walla appear to be, in almost all the forte that have been examined, partially thrown down ; in some, " the vitrified ruins," Williams states, " are nearly all grown over with heath and grass, and nat' appear at first sight like the ruins of some earth or sod buildings :" fruit; the instances in which the structure memo to be the most entire, it may be oonjoctured that its original height was commonly about twelve feet.