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ON ANTIQUITIES IN SCOTLAND.
Continued from vor. viii. p. 333.
ON VITRIFIED FORTIFICATIONS.
I Now proceed to the sixth kind of antiquities me n tioned in a former paper, viz. those vitrified forts that have been lately discovered on the tops of many high hills in Scotland.
It is not yet three years since I got the first hint of this species of building*, from a gentleman who had examined them with attention; and who was, I' believe, the first person who took notice of them in Scotland. This was Mr John Williams, who was for several years employed by the honourable board of trustees for managing the forfeited estates in Scotland, as a mineral surveyor on these estates †. Since that time, I have seen and examined them myself,. and have made the following observations upon them :
These walls consist of stones piled rudely upon one another, and firmly cemented together by a matter that has been vitrified by means of fire, which forms a kind of artificial rock, (if you will admit this phrase,) that resists the vicissitudes of the wea-. ther, perhaps better than any other artificial cement that has ever yet been discovered.
*This part of the account was written in April 1777; and published in the fourth volume of the Archeologia. Several particulars are now added to that account.
+ See his account of them in a series of letters to. C. M. esq. published about the year 1777, 8vo, with a plate.
All the walls of this kind that I have yet seen or heard of, have been evidently erected as places of defence. They, for the most part, surround a small area on the top of some steep conical hill, of very difficult access. It often happens that there is easier access to the top of one of these hills at one place than at any other; and there they have always had the entry into the fort, which has always been defended by outworks, more, or lefs strong, according to the degree of declivity at that place. If the form of the hill admitted of accefs only at one place, there are outworks only at one place; but if there are more places of easy accefs, the outworks are opposed to each of them, and they are proportioned in extent to the nature of the ground.
The first fortification of this kind, that I saw, was upon the top of a steep hill called Knock-ferrel, two miles west from Dingwall in Rofsfhire. And as an idea of all the others may be formed from this one, I fhall here subjoin a particular description of it.
The hill is of a longish form, rising into a ridge at top, long in proportion to its breadth. It is of great height, and extremely steep on both sides; so that when it is viewed at a distance from either end, it appears of a conical shape, very perfect and beautiful to look at; but, when viewed from one side, one of the ends is seen to be much steeper than the other.
The narrow declivity of the hill is of easy access, and forms a natural road by which you may ascend to the top on horseback; and at this end has been the entry into the fort A. (see plan.) This fort consists, as I guessed by my eye, of a long eliptical area of near
an acre, which is entirely level, excepting towards each end, where it falls a little lower than in the middle. The fortification of vitrified wall, CC is continued quite round this area; being adapted to the form of the hill, so as to stand on the brink of a precipiece all round, unless it be at the place where you enter, and at the opposite end, B; both which places have been defended by outworks. Those at the entry had extended, as I guessed, about.an hundred yards, and seem to have consisted of crofs walls one behind another, eight or ten in number; the ruins of which are still plainly perceptible. Through each of these walls there must have been a gate, so that the besiegers would be under the necessity of forcing each of these gates succefsively before they could carry the fort; on the opposite end of the hill, as the ground is considerably steeper, the outworks seem not to have extended above twenty yards, and consist ordy of two or three crofs walls. Not far from the further end was a well, marked D, now filled up, but still discoverable.
To assist you in forming an idea of this structure, I subjoin a plan of the hill with its fortification, as if it were complete. This is drawn entirely from memory, and is not pretended to be exact in proporthe general form, and is sufficiently exact for our purpose here.
tions; but it has
The wall all round, from the inside, appears to be only a mound of rubbish, consisting of loose stones, now buried among some earth, and grafs that has been gradually accumulated by the dunging of sheep,
which resort to it as a place of shelter.
wall is only to be seen on the outside.
· PLAN OF KNOCKFERREL.
Nor are these walls readily distinguishable at a distance, because they are not raised in a perpendicular direction, but have been carried up, sloping inwards at top, nearly with the same degree of inclination as the sides of the hill; so that they seem, when viewed at a small distance, to be only a part of the 'hill itself.
It appears at first sight surprising that a rude people should have been capable of discovering a cement of such a singular kind as this is. It is lefs surprising that the knowledge of it should not have been carried into other countries, as distant nations in -those periods had but little friendly intercourse with one another. But it is no difficult matter for one who is acquainted with the nature of the country VOL. ix.
May 30: where these structures abound, to give a very probable account of the manner in which this art has been originally discovered, and of the causes that have occasioned the knowledge of it to be lost, even in the countries where it was once universally practised.
Through all the northern parts of Scotland, a particular kind of earthy iron ore, of a very vitrescible nature, much abounds. This ore might have been accidentally mixed with some stones at a place where a great fire was kindled; and being fused by the heat, would cement the stones into one solid mass, and give the first hint of the uses to which it might be applied. A few experiments would satisfy them of the possibility of executing at large what had been accidentally discovered in miniature.
This knowledge being thus attained, nothing seems to be more simple and natural than its application to the formation of the walls of their fortified places.
Having made choice of a proper place for their fort, they would rear a wall all round the area, building the outside of it as firm as they could of dry stones piled one above another, the interstices between them being filled full of this vitrescible iron ore; and the whole supported by a backing of loose stones piled carelessly behind it.
When the wall was thus far completed, with its facing all round reared to the height they wished for, nothing more was necefsary to give it the entire finishing but to kindle a fire, all round it, sufficiently intense to melt the vitrescible ore, and thus to cement the whole into one coherent mafs, as far as the influence of that heat extended. As the country then