In the year 1777, an account was published by Mr John Williams, mineral-engineer, of certain remains of ancient buildings on the summits of some of the hills in the Highlands of Scotland, which had hitherto escaped observation, and which to him afforded grounds for a very extraordinary supposition, That they had been cemented together by means of Fire. He mentioned several of those hills exhibiting remains of building, which he had visited and examined; particularly the hill of Knockfarril in Ross-shire, Craig-Phadrick near Inverness, Dun-Evan and Castle-Finlay in the county of Nairn, and the Castle-hill of Finhaven in the county of Angus. He described the vestiges of regular fortifications on the summits of those hills, of which the walls, remaining in some places of several feet in height, were evidently compacted together by the vitrification of the stones of which they were built; and he offered some ingenious conjectures with regard to the means employed in forming such extraordinary structures, and the purposes for which they might have been reared.