Crannoges are artificial islets raised above the level of certain lakes in Ireland and Scotland[20] by means of a series of layers of earth and stone, and strengthened by piles, some upright, others laid down lengthwise. Wylde counted forty-six in Ireland in his time, some of them of considerable extent. That of Ardkellin Lough (Roscommon) is surrounded by a wall of dry stones resting on piles. In other places have been found the remains of stockades very intelligently set up in such a manner as to break the force of the shock of the water.
To add to the difficulties of dealing with the subject of crannoges, they were successively occupied for many centuries. They are mentioned in the most ancient Irish legends, and even in the sixteenth century they served as refuges for the kings of the country in the constant rebellions that took place. The objects taken from the lakes belong to very different epochs, and it is impossible to say anything positive as to the time of their construction.
A but found in Donegal may, however, date from an extremely remote age.[21] It rested on a thick layer of sand brought front the neighboring shore, and was covered over by a bed of peat slot less than sixteen feet thick. Since the hilt was deserted by man the peat had gradually accumulated till it had at last invaded the dwelling itself. The but included a ground-floor, and one story about twelve feet long by nine wide and four high. The walls consisted of beams scarcely squared, joined together with wooden mortices and pegs. The roof, which was probably flat, consisted of oak planks, the spaces between which had been filled in with mortar made of sand and grease. On the ground-floor lay several flint implements, showing no signs of having been polished, a quartz wedge, and a stone chisel, which had evidently seen long service. This chisel, the discoverers say, corresponded exactly with the notches around the mortices. A regular paved way, formed of sea-beach pebbles placed on a foundation of interlaced branches, led up to a hearth made of flat stones measuring some three feet every way. All about lay fragments of charcoal and broken nuts, the latter partly burnt. Another but, with an oak floor resting on four posts, has recently been discovered in County Fermanagh, beneath a deposit of peat about twenty feet thick. No trace of metal has been found in either of these Irish buts, and the thickness of the peat beneath which they lay is another proof of their great antiquity. One serious objection, however, is this: Were the Irish sufficiently advanced in prehistoric times to be able to erect dwellings implying so considerable an amount of civilization?
Crannoges are met with in Scotland as well as in Ireland, and excavations in Loch Lee have enabled explorers to make out their mode of construction. The Lake Dwellers began by piling up a number of trunks of trees in the shallower waters of a lake. They then strengthened these trunks with branches or beams about which the mud collected till the whole formed an islet. All about this islet, beneath the waters of the lake, were found various objects in stone, wood, and horn, as well as some canoes several feet long. Similar crannoges are to be seen on the lakes of Kincardine and Forfar, which Troyon thinks date from the Stone age.[22] If he be right, and we should not like to make any assertion one way or the other, the bronze objects and the enamelled glass bowls found near these dwellings prove that they were occupied by several successive generations.
It is probable that Lake dwellings were also used in Asia and in Africa from prehistoric times. History tells us that the inhabitants of Phasis, the Mingrelians of the present day, lived in reed huts on the water, and that they went from one islet to another in canoes hollowed out of the trunks of oak-trees. A bas-relief from the palace of Sennacherib, preserved in the British Museum, represents warriors fighting on artificial islands made of large reeds. But here w e enter the domain of history, and we must return to Neolithic times, and speak of the habitations built of more durable materials and the ruins of which are still standing.
It is impossible to say with any certainty to what period the most ancient of these structures belong. It is probable that man early learned to pile up stones, binding them together at first with clay, and then with some stronger cements. The burghs of Scotland, the nurhags of the island of Sardinia, the talayoti of the Balearic Isles, the castellieri of Istria, are all ancient witnesses of the modes of building employed in the most remote ages.
Burghs, brocks, or broughs are numerous in Scotland,[23] and also in the islands of the Atlantic. For a long time they were supposed to be of Scandinavian origin, but Sir J. Lubbock[24] remarks With reason that no building at all like them exists in Norway or in Denmark, and it is difficult to admit the idea that the Scandinavians set up in the islands tributary to them buildings which were unknown to their own mainland. We are therefore disposed to think that these curious structures, which were inhabited until the twelfth and thirteenth centuries of the Christian era, are of much earlier date than the first invasion by the Northmen, and that the burgh still standing on the little island of Moussa, one of the Shetlands, is one of the best examples that we can quote. A tower, forty-one feet high, rises on the borders of the sea. The walls are of unhewn stones, piled up without cement, and they form two circles, separated by a passage four feet wide. In each story are a series of very small openings, intended to admit air and light to the cell-like rooms inside, and to a staircase that leads to the top of the tower. The only way into this burgh is through a door only seven feet high, and so narrow that it is impossible for two people to go in abreast.
The regularity of the building of this burgh, and the architectural knowledge it implies, prevent our ascribing it either to the Stone or even to the Bronze age; but we find in Scotland itself more ancient examples, if we may so express ourselves, of domestic architecture. These examples are subterranean dwellings, made of rough-hewn stones of considerable size, laid down in regular courses, to which the names of earth-houses, Picts’ houses, and weems have been given. The walls converge towards the centre, leaving an opening at the top, which was covered in with large flat stones. These dwellings are certainly of earlier date than the burghs, and the discovery of a Picts’ house actually beneath the ruins of a burgh enables us to speak with certainty on this point.
In Ireland similar proofs have been found of the great antiquity of roan. More than one hundred towers have been found in that country, all built of large stones, and varying in height from seventy to one hundred and thirty feet, with a diameter of from eight to fifteen feet. The most diverse origins have been attributed to these towers, from prehistoric times to the centuries immediately preceding the Christian era; from the time of the Druids to that of the Friars. According to the point of view of different archæologists, they have been called temples of the sun, hermitages, phallic monuments, or signal towers.
We meet with a similar problem in considering the nurhags, as in considering the burghs. They have been justly called a page of history, written all over the surface of Sardinia by an unknown people. Count Albert de la Marmora counted three thousand of them a few years ago, and more recent explorers tell us that this number is greatly exceeded. Like the burghs, which they strangely resemble, the nurhags are conical towers with very thick walls made of huge stones, some Hewn, others in their natural state, arranged in regular courses without mortar. On entering one of them we find ourselves in a vaulted room, which looks exactly like one half of an egg in shape. In the upper stories are two, and sometimes three rooms, one above the other, to which access is gained by steps cut in the walls. The whole structure is crowned by a terrace ([Fig. 53]). We must add that the entrance to the nurhag is through an opening on a level with the ground, and so low that one can only go in by crawling on the stomach.