From fragments of skeletons usually found in the vicinity of dolmens, it has been imagined that either the priests or their human offerings were buried there as upon consecrated ground. There are several instances where these dolmens form covered ways or avenues, being placed one beside another in continuous line, and generally surrounded by a plantation of trees. They are frequently divided by blocks of stone into several compartments, and, like the tumuli or barrows, were probably used as places of interment for the dead. The most interesting, perhaps, of any of these groups of stones are the “cromlechs”: enclosures formed of numerous boulders, arranged either in elliptic rows or in concentric circles, with a large monolith in the central point. Each circle is composed of a definite number of “menhirs,” and the whole is usually surrounded by a ditch. It is supposed that each stone represented a minor deity, and the central one the chief of the gods. Their purpose apparently was to mark the place of large assemblies, called together for the administration of civil, military, and religious rites. The cromlech of Stonehenge in Wiltshire is the most celebrated and one of the largest known. The country folk call it the Cor-Gaur, or dance of giants, and attribute its formation to the magic of the famous enchanter, Merlin. It is composed of two circular and two elliptic enclosures, the one within the other, and is several hundred feet in circumference. In none of these Celtic monuments is there anything which may be called strictly architectural, but some of them illustrate a principle of building which is of importance to note. To place a row of stones in upright positions denotes no special phase of intelligent thought, beyond a desire to permanently mark some interesting locality, but when the ancient race which raised these massive rocks conceived the idea of supporting one block upon a number of smaller ones, it had reached a first principle of construction, destined to be employed for many centuries afterward in some of the finest buildings. After the trilithon came the table-stones, and from these it was but a step to the covered alleys, which were in themselves a first conception of a rude habitation, walled in and roofed over. There can be nothing more elementary than this, and no simpler constructional expedient, in whatever country it may first have been evolved. We do not know the precise date of Celtic monuments, nor is it probable that they are as ancient as the Egyptian pyramids, but as in any case they illustrate the transition from brutal ignorance to an era of thought, we may place them at the commencement of our chronological list. In the various themes and discussions advanced by archæologists, and the strange legends and tales of the peasantry with regard to them, we have no concern. It is sufficient for us to know that they exist and afford us an insight into the dawning efforts of a