I believe it was John Stuart that first made the remark:--"Remove the cairn from New Grange, and the pillars would form another Callernish;"[299] and there seems little doubt but that this is the true explanation of the peculiar form of the monument. Nor is it difficult to see why this should be the case; for it must be borne in mind that the whole of the chambers and the access to them must have been constructed, and probably stood, naked for some time before they began to heap the cairn over them. Calliagh Birra's tomb (woodcut No. 80), and the numerous "Grottes des fées" we meet with in France and elsewhere I look on as chambers, some of which it was intended should be buried in tumuli, which, however, never were erected: others, when men had become familiar with the naked forms, were like many dolmens, never intended to be hidden. It may be a mere fancy; but I cannot escape from an impression that, in many instances at least, the chambers were constructed during their lifetime by kings or chiefs as their own tombs, and that the cairn was not raised over them till the bodies were deposited in their recesses. This, at least, is the case in the East, where most of the great tombs were erected by those who were to lie in them. During their lifetime they used them as pleasure-houses, and only after their death were the entrances walled up and the windows obscured, so as to produce the gloom supposed to be appropriate to the residences of the dead. Another point is worth observing. It seems most improbable that sculptures, such as are found in the Irish and French chambered tumuli, could have been executed by artificial light. Either the stones were sculptured before being put into their places--which, to say the least of it, is very unlikely; or they were sculptured while the light could still penetrate through the interstices of the stones forming the walls. In any case, however, the naked forms of these chambers must have been perfectly familiar with those who used them; and there is no difficulty in understanding why, as at Carrowmore or Callernish, they should have repeated the same forms which were certainly never intended to be covered up. From the occurrence of a similar form at Northern Moytura (woodcut No. 59), used externally also, it may be argued that this may be of the same age. The Irish example, as explained above, is probably of the same age as the great chambered tumuli of Meath; but there seems to be a difference between the two, which would indicate a very different state of affairs.