126 A History of Art in Sardinia and Jud^a. of the preceding, consists of twenty-two figures carved upon the same soHd rock (N P in plan), and the third is represented by two figures inside a small hollow, interposing between the principal chamber and the passage (L M in plan). The wall, to the height of a few feet, was cut perfectly smooth, followed by the figures, which formed a raised band, but above them the rock was left rough, constituting a rude natural frame, not devoid of a quaint charm of its own. A layer of yellowish glaze was added to these sculptures, per- haps to heighten their effect, certainly to protect them at the same time against the injurious action of the elements. Notwithstand- ing these precautionary measures, owing also to the nature of the limestone on which the figures are carved, which is coarser and less resisting than marble, many of them are much worn and nearly obliterated, notably those furthest removed from the centre, where the sun never penetrates, but where wind and rain are free to carry on their work of destruction. No wonder that large patches of mould and lichen should have spread over these rocks, making the figures hard to distinguish from the surrounding surface. Hence it often happened that M. Guillaume, before he proceeded to photograph them, was obliged to scrape off with the knife the green vegetation, guided thereto by his fingers, which felt for the general contour, and the details of the pictures, throughout in very flat relief. The pavement of the main chamber is now covered with grass and brushwood ; that this was not so in olden times we proved by clearing a small space of the earth and rubbish which have accumulated, when the rock-floor perfectly levelled out, and traces of a side canal (Plate VHL, A B C) came to light. Fronting the bas-relief on the right (Plate VHI., G), is a ledge with a projection of lo to 12 c. from the rock. It may have been an altar or a pedestal, more likely the former, as a statue placed on it would have been right in front of an important figure carved on the rock behind it, and so have concealed it from public gaze. The base of this altar, which we disengaged, is Indicated by dots. We also took soundings at the entrance of the main chamber and the rock above it, for the purpose of ascertaining the existence of some kind of door or roof, but without result. Consequently, it was from the beginning an irregular excavation open to the sky. A certain amount of thought was bestowed towards securing diversity