The mounds are sometimes of considerable size, and are wholly or largely built up of fine materials, as earth, clay, sand, and gravel; and if large stones enter into their composition, they are not intermixed with the finer constituents, but form a platform or pavement, a layer, or a capping. Occasionally they disclose the curious constructional feature of two or more different materials arranged in alternate layers. Such a barrow was opened at Gorsey Close,[26] near Tissington, in 1845; its soil was found to be interspersed with alternate layers of moss and grass. Another at Roylow,[27] near Sheen, gave very similar results. It is also noticeable that these barrows are often found in comparatively low-lying places. [26] _Vestiges_, 80. [27] _Proc._ Soc. Ant., 1895. In every known instance, the interment over which the mound was raised had undergone cremation, and this applies to the few secondary interments which have been noticed. The bodies had invariably been burned on the spot, and the hard-baked floors, strewn with charcoal and ashes, are a notable feature of these “late” barrows. The excessive heat of the funeral pile has so completely reduced the bones that they have often escaped detection altogether. There is reason to think that these calcined remains were sometimes left as they were deposited by the fire; but in a few instances they were found occupying a shallow circular hole in the natural surface into which they had been swept after the fire was extinguished. This may have been a common practice, for the presence of a small depression of the kind might easily be overlooked by the explorer. On the other hand, there was evidence that in some of these barrows the human ashes had been collected and placed near the summit of the mound; and the large stones which have occasionally been observed in this position may have been the relics of the receptacle which contained them. We thus seem to have a “low-level” and a “high-level” type, but whether this indicates a difference of period is by no means certain. The general trend of evidence shows that some effort was made to seal down, so to speak, the site of the pyre and its contents by a layer of puddled clay or earth, which was hardened by a fire upon it, or by a layer of large stones instead.