VITOR  IA

June stet, t8t; the yenerol oharnot.r of the ground bawd. the dodorro eM tM Betas urea broken and'eaadµ hilly a+d intersected by nervy Omani ../ , Puebla de Minnows Redrawn from Major-General C . W . Robinson's Wellington's Campaigns, by permission of Hugh Rees, Ltd . BmeryVNter or- in all probability, constituted an essential feature in the Scottish forts . Except on the hypothesis of buttresses of a similar kind, it is impossible to explain the vast quantities of loose stones which are found both inside and outside many of the vitrified walls . The method by which the fusion of such extensive fortifications was produced has excited much conjecture . Williams maintained that the builders found out, either during the process of smelting bog-ore, or whilst offering sacrifices, the power of fire in vitrifying stone, and that they utilized this method to cement and strengthen their defences . This view has been keenly controverted, and it has been suggested that the vitrified summits were not forts but the craters of extinct volcanoes, an hypothesis long since abandoned; that they are not so much forts as vitrified sites, and that the vitrescence was produced by fires lighted during times of invasion, or in religious celebrations; and, lastly, that if they were forts they must originally have been built of wood and stone, and that their present appearance is due to their being set on fire by a besieging enemy . The theory of Williams has, with modifications, been accepted by the principal authorities . It is supported by the following facts: (1) The idea of strengthening walls by means of fire is not singular, or confined to a distinct race or area, as is proved by the burnt-earth enclosure of Aztalan, in Wisconsin, and the vitrified stone monuments of the Mississippi valley . (2) Many of the Primary rocks, particularly the schists, gneisses and traps, which contain large quantities of potash and soda, can be readily fused in the open air by means of wood fires—the alkali of the wood serving in some measure as a flux . (3) The walls are chiefly vitrified at the weakest points, the naturally inaccessible parts being unvitrified .

(4) When the forts have been placed on materials practically infusible, as on the quartzose conglomerates of the Old Red

Sandstone, as at Craig Phadraic, and on the limestones of Dun Mac Uisneachain, pieces of fusible rocks have been selected and carried to the top from a considerable distance . (5) The vitrified walls of the Scottish forts are invariably formed of small stones which could be easily acted upon by fire, whereas the outer ram-parts, which are not vitrified, are built of large blocks . (6) Many of the continental forts are so constructed that the fire must have been applied internally, and at the time when the structure was being erected . (7) Daubree, in an analysis which he made on vitrified materials taken from four French forts, and which he submitted to the Academy of Paris in February 1881, found the presence of natron in such great abundance that he inferred that sea-salt was used to facilitate fusion . (8) In Scandinavia, where there are hundreds of ordinary forts, and where for centuries a system of signal fires was enforced by law, no trace of vitrifaction has yet been detected . A great antiquity has been assigned to vitrified forts, without sufficient proof . Articles of bronze and iron have been found in the Scottish forts, while in Puy de Gaudy a Roman tile has been discovered soldered to a piece of vitrified rock . In a few of the German forts Professor Virchow found some of the logs used as fuel in vitrifying the walls, and he concluded from the evenness of their cut surfaces that iron and not stone implements must have been used . These results indicate that these structures were possibly in use as late as the early centuries of the Christian era . It has been suggested that they were built as refuges against the Norsemen . Much in the situation and character of the forts favours this supposition . This is especially the case with reference to the Scottish forts .

Here the vitrified summits are invariably so selected that they not only command what were the favourite landing-places of the vikings, but are the best natural defences against attacks made from the direction of the seacoast . In

Saxony and Lusatia the forts are known as Schwedenburgen, and in the Highlands of Scotland as the fortresses of the Feinne designations which also seem to point to an origin dating back to the times of the vikings . J . Anderson, Scotland in Pagan Times (1886); C . MacLagan, The Hill Forts of Ancient Scotland; Thomas Aitken, Trans . Inverness Scientific Soc. vol. i.; Charles Proctor, Chemical Analysis of Vitrified Stones from Tap o' Noth and Dunideer (Huntly Field Club); various papers in Proceedings of Soc . Antiq . Scot . (since 1903 The Scottish Historical Review) and Proceedings of Royal Irish Academy; R . Munro, Prehistoric Scotland (1899); G . Chalmers, Caledonia (new ed., 7 vols., Paisley, 1887–94); Murray's Handbook to Scotland (1903 ed.) ; Leonhard, Archie fur Mineralogie, vol. i.; Virchow, Ztschr. fur Ethnologie, vols. iii. and iv.; Schaaffhausen, Ver-handlungen der deutsch. anthrop . Gesellschaft (1881); Kohl, Verhand. d. deutsch. anthrop .

Gesellschaft (1883); Thuot, La Forteresse vitrifiee du Puy de Gaudy, &c.; De Nadaillac,

Les Premiers Hommes, vol. i.; Mimoires de la Soc . Antiq. de France, vol. xxxviii.; Hildebrand, De forhistoriska folken i Europa (Stockholm, 188o) ; Behla, Die vorgeschichtlichen Rundwalle im dstlichen Deutschland (Berlin, 1888) ; Oppermann and Schuchhardt, Atlas vorgeschichtlicher Befestigungen in Niedersachen (Hanover, 1888–98) ; Zschiesche, Die vorgeschichtlichen Burgen and Walle im Thuringer Zentralbecken (Halle, 1889); Bug, Schlesische Heidenschanzen (Grottleau, 1890) ; Gohausen, Die Befestigungsweisen der Vorzeit and des Mittelalters (Wiesbaden, 1898) . (R .