Both the Enclosed and the Encircled Barrows are frequently of large dimensions, and indicate by their contents that they belong to the later era, when the metallurgic arts had been introduced. In various instances the contents of the enclosed barrow, or tumulus surrounded with an earthen vallum, clearly prove it to belong to the Roman era. In one, for example, in the neighbourhood of Rutherglen, Lanarkshire, which measured 260 feet in circumference, a gallery or long chamber was discovered, constructed of unhewn stones, and containing, among other relics, two brass vessels, which from the description appear to have been Roman patellæ. On the handle of each of them was engraved the name CONGALLUS or CONVALLUS. With these were deposited various native relics, including a perforated stone and three large glass beads, such as are frequently found in earlier British tumuli.[59] Examples, however, are not wanting of the enclosed barrow with contents belonging to an earlier period. One of such formed the largest of a group which occupied the summit of one of the Cathkin hills in the parish of Kilbride. It measured eighteen feet in height, and one hundred and twenty feet in diameter, and bore the name of Queen Mary's Law, from a popular tradition that the hapless Mary watched from its summit the ebbing tide of her fortunes on the fatal field of Langside. This interesting memorial, thus associated with two widely severed periods of Scottish history, afforded building materials to the district for many years, until in 1792 some workmen while employed in removing stones from it, exposed to view a vault or chamber situated towards the west side of the mound, and containing twenty-five rude cinerary urns. They were placed, as is most usual in the earlier sepulchres, with their mouths downward, and underneath each urn lay a piece of white quartz. Exactly in the centre of the cairn a rude cist was discovered measuring nearly four feet square, and among a quantity of human bones which surrounded it were two rude fibulæ of mixed metal, and an armilla or ring of cannel coal. Another fibula and an equally rude metal comb were found in one of the urns.[60]