It remains to account for the vast number of images to be found in the quarry. A certain number have, no doubt, been abandoned prior to the general cessation of the work; in some cases a flaw has been found in the rock and the original plan has had to be given up—in this case, part of the stone is sometimes used for either a smaller image or one cut at a different angle. In other instances the sculptors have been unlucky enough to come across at important points one or more of the hard nodules with which their tools could not deal, and as the work could not go down to posterity with a large wart on its nose or excrescence on its chin, it has had to be stopped. But when all these instances have been subtracted, the amount of figures remaining in the quarries is still startlingly large when compared with the number which have been taken out of it, and must have necessitated, if they were all in hand at once, a number of workers out of all proportion to any population which the island has ever been likely to have maintained. The theory naturally suggests itself that some were merely rock carvings and not intended to be removed. It is one which needs to be adopted with caution, for more than once, where every appearance has pointed to its being correct, a similar neighbour has been found which was actually being removed; on the whole, however, there can be little doubt that it is at any rate a partial solution of the problem. Some of the images are little more than embossed carvings on the face of the rock without surrounding alley-ways. In one instance, inside the crater, a piece of rock which has been left standing on the very summit of the cliff has been utilised in such a way that the figure lies on its side, while its back is formed by the outward precipice (fig. 56); this is contrary to all usual methods, and it seems improbable that it was intended to make it into a standing statue. Perhaps the strongest evidence is afforded by the size of some of the statues: the largest (fig. 55; no. 64, fig. 60) is 66 feet in length, whereas 36 feet is the extreme ever found outside the quarry; tradition, it is true, points out the ahu on the south coast for which this monster was designed, but it is difficult to believe it was ever intended to move such a mass. If this theory is correct, it would be interesting to know whether the stage of carving came first, and that of removal followed, as the workmen became more expert; or whether it was the result of decadence when labour may have become scarce. It is, of course, possible that the two methods proceeded concurrently, rock carvings being within the means of those who could not procure the labour necessary to move the statue.