the people, as to be above the imputation of blame, or be sunk so low as not to admit of having his cause pleaded by a friend! Fortunate are the people when they have it not in their power to silence their best instructors! Blefsed is the state when the peacemaker can raise his voice without fear, and dares to allay that fury, which, if unrestrained, leads either to implicit obedience, or rafh deeds of barbarism, that makes the heart to fhudder! It is in this state of things, only, that perfect political freedom can be enjoyed. Long, then, may such writers as Thunderproof be permitted to exert their talents. A foolish proclamation may be disregarded, while the law can be enforced. But who fhall set limits to the power of a headstrong populace, when they believe that they are. authorised to decide. *?. ALCIBIADES.

ON ANTIQUITIES IN SCOTLAND.

Continued from p. 134.
CATIONS.

VITRIFIED FORTIFICATIONS..

I AM AM much disposed to believe that vitrified fortifi cations have been entirely a British invention, and think it probable that the art was never carried out.

That impartiality on which the Editor piques himself, induces him to insert the above. He is not conscious that the changes against either himself or his correspondent are well founded. He does not pretend to adopt the opinions of his respective correspondents. His aim is only to guard against admitting any thing that he thinks can have a pernicious tendency, and to do full justice to the arguments of his correspondents. Controversy he must avoid, but a difference of opinion, where that is ex- prefsed with temper, even where it militates against his own, he thall ever : cherish. It is in consequence of such differences in opinion that truth'can a best be attained.

of this country. That it was not known by the Danes, at least, seems extremely probable, from a curious fact that I fhall now take notice of; and if it was not known by the Danes, it seems probable, that it would not be known by the other northern nations on the continent. The fact I allude to is as follows : It is well known that the Danes made frequent inroads into Scotland, for several centuries, with various degrees of succefs. During that period they seized upon a peninsulated rock in the Murray frith, about four miles from Elgin, which is now called Brough-head. As this was a place naturally strong, and formed besides a kind of harbour, by means of which supplies could be brought to it by sea, they thought it a very convenient station to be occupied as a place of arms, and accordingly fortified it for that purpose. Three large and deep parallel ditches were drawn across the neck of the isthmus that joined it to the land; and within the innermost of these`a large wall has been erected, which has been continued quite round the peninsula, as the ruins of it at this day clearly fhow.

The circumstance that made me here take notice of this Danish fortification, is, that all the stones on the outside of the wall, appear to have been scorched in the fire in so much that they appear almost as red, on that side, as bricks, although the stone is naturally of a very white kind, and some of them are almost burnt to a powder. Between these stones, on digging among the ruins of the wall, is found a good deal of reddish dust, exactly resembling dry clay, that has been burnt to alhes. But in no part of this fortification is there the smallest appearance of vitrified matter, and the stones in the inside are every where of their natural. colour.

From these circumstances it appears to me ex tremely probable, that the Danes, from having seen; in their incursions, some of the vitrified fortifications,. have admired the invention, and wifhed to imitate. them. We may suppose they might have been able, to learn in general that they consisted of walls of stone, intermixed with dry clay in powder, which was afterwards converted into a vitrified mass by surrounding the whole with a stack of wood, or other combustibles, and then setting it on fire. But having. been ignorant of the necessity of employing only that particular fubstance already described, which, from its general appearance, might be, on some occasions, mistaken for a kind of clay, they have probably taken some ordinary clay and employed that in its stead. But as ordinary clay is hardly at all vitrescible, they have not been able to succeed in their attempt; but, instead of that, the stones, by the great heat applied to them, have been scorched in the manner they now appear, and the clay between them has been burnt to aíhes. This so perfectly accounts for the peculiarity observable in the ruined walls of this fortification, and it is so difficult to afsign any other reason for the singu lar appearance of them, that I could not avoid throwing this probable conjecture to direct towards other.

researches.

Although it is only of late that the real nature of these vitrified walls has been known, it is long since the vitrified matter has been observed; but it was always supposed that these were the natural production of volcanoes; from whence it was inferred that volcanoes had been very common in Scotland, at some disvery tant period. But if no better proof can be adduced

i

in support of this last hypothesis it will hardly be admitted.

From the foregoing account it appears, that these works are purely artificial. At the same time it must be owned, that the natural appearance of the places where these vitrified masses are usually found, is well calculated to favour the opinion that they have been produced by volcanoes.

The vitrified matter is usually first discovered by travellers around the bottom, and on the sides of steep hills, frequently of a conical fhape, terminating in a narrow apex, exactly resembling the hills that have been formed by the eruptions of a volcano. It is therefore very natural to think that these may have been produced in the same way.

Let us suppose that a traveller, strongly imprefsed with this idea, fhould resolve to examine the top of the mountain more nearly, and, for this purpose, ascends to the summit; would not his former conjecture be much confirmed, when, at the top, he should find himself in a circular hollow, surrounded on all sides by matter, rising gradually higher, to the very edge of the precipice, which is there entirely environed with vitrified matter, of the same kind with thathe had found at the bottom? Could such a man be called unreasonably credulous, if he fhould be induced by so many concurring circumstances to believe that this had been a real volcano? But would he not be reckoned sceptical in extreme, if he should entertain the smallest doubt of the truth of this opinion, if he likewife sees the very opening itself in the centre of the hollow, through which the boiling lava had been spewed out. Yet strong as all these appearances are, we know.

that they may, and actually do, all concur, on many occasions, to favour the deceit. The formation of the hollov bason has been already explained; and the well, with which every one of these forts has been provided, and which is still discoverable in all of them, though, for the most part, now filled up with - stones to prevent accidents, might very readily be mistaken for the mouth of the volcano.

T

In these circumstances, a casual visitor may be excused if he should believe in such strong appearances, without inquiring minutely into the matter. But a philosophical inquirer, who resolved coolly to investigate the matter, would soon find reason to suspect that he might be mistaken. The vitrified masses themselves are of a nature extremely different from real lava; so different, indeed, that nothing but the difficulty of accounting for the way in which they could be otherwise produced, would ever have occasioned them to be confounded with one another. In real lava, the heat has been so intense as to fuse almost all matters, and reduce them into one homogeneous mafs; but in the matter of which we now treat, the heat has been so slight as to vitrify scarce any of the stones, but barely to fuse the vitrescible matter that was interposed between them; which, alone, points out a very efsential difference between the nature of the two. But if he fhould proceed farther in this investigation, he would also discover, on digging into the hill in any part, that no lava, or any other matters that flow marks of having been in the fire, are to be found; but that they consist of rock, or other strata of mineral matter, similar to what is found in other parts of the country. Ne