Both caves are built of uncemented stones unmarked by any tool. The cave at Chyoster extended originally, as appears from its remains and the rubbish left by its recent spoilers, fifty feet or more in a straight line up the sloping side of the hill. It is 6 feet high, 4 feet wide on the top, and 8 feet wide at the bottom, and is thought to have been originally a storehouse. It appears to have been built on the natural surface of the hillside, and then covered over with stones and earth, and planted with the evergreens which still abound there. A few years subsequently to the above investigations, in one of those intellectual excursions by means of which our acquaintance with the early history of our island is so greatly extended, the following results were arrived at:--In the autumn of 1865, in an excursion made jointly by the Royal Institution of Cornwall and the Penzance Natural History Society, they inspected on the north coast of the county, Gurnard's Head, a rocky promontory, jutting some distance into the sea, and bearing very distinct traces of having been fortified by the early Britons against an enemy attacking from the sea, this being the only specimen of an ancient British fortification where traces of sea defences have been found. In all other cases they seem to have been erected as a protection from an attack by the land side, and to have been evidently the last retreat of the natives. Next was visited the Bosphrennis Bee-hive Hut, first brought to light by the Cambrian Archæological Society: it was seen in clusters or villages by Cæsar. And, on an eminence near the village of Porthemear, was found a large inclosed circle, now hidden by briars and thorns, which, on examination, showed the remains of several circular huts, leaving no doubt that here a considerable ancient British village had once existed. Of the homes of the Picts, the most distinguished among the barbarous tribes inhabiting the woods and marshes of North Britain, there remain some specimens in the Orkneys: they are rude and miserable dwellings underground, but they are supposed to be calculated for the requirements of a more advanced state of society than that of the dwellers in Picts' houses. A complete drawing of one of the Orkney specimens has been made, and was exhibited to the British Archæological Association in 1866. [Illustration: PICTS' HOUSE.]