It is not to be supposed that all lake-dwellings are of great antiquity; some are no doubt of much earlier date than others, but the question of their precise age is especially complicated from the fact that, at whatever period they were constructed, many were occupied through a long period of historic time. Crannogs are frequently mentioned in the Irish ‘Annals,’ and they enter into the composition of several place-names. Many of them suffered from the attacks of the Norsemen, as records tell us. We have clear historic evidence of the occupation of some of the lake-dwellings throughout the Middle Ages, and through the Elizabethan wars down to the middle of the seventeenth century.[120] In many, as we have seen, flint cores, with flakes, scrapers, knives, and arrow-heads, have been found. With them sometimes occurred stone celts, exactly similar to examples found in primitive cists, with burial urns and evidences of cremation. No doubt crannogs yielding flint and worked stone should be regarded as the oldest; yet from the fact that spear-heads, celts, and other articles of bronze, and even of iron, are at times found plentifully amongst their piling, or in the surrounding bog stuff, we must conclude that these islets had been used by a people well skilled in the art of metallurgy. It is necessary, too, to point out that year by year additional evidence is produced to show that in Ireland at least the apparently contemporaneous use of flint, stone, bone, bronze, and iron in the preparation of weapons, implements, and ornaments for the person, had existed throughout a long period of time. In addition to the mixed ‘finds’ already mentioned, there were found, in a Monaghan lake-dwelling described by Mr. Shirley, stone celts, a worked flint, apparently intended for an arrow-head, three looped bronze celts, a dagger and chisel of bronze, as also two bronze arrow-heads and a shield-boss of the same metal, accompanied by iron remains. At a place named ‘The Miracles,’ near Monea, Co. Fermanagh, in 1875, a lake-dwelling, the remains of which Mr. Wakeman had an opportunity of examining, was discovered by turf-cutters. Here a fairly polished axe-head, or celt, was turned up, together with a number of articles composed of bronze, which, from the description given by the people who had found them, were probably fibulæ. That, during some portion of the period of its occupation, inhabitants of this crannog were in the habit of manufacturing objects of iron was evident, as pieces of iron slag, quantities of wood charcoal, a well-formed crucible, sharpening-stones, and at least two grinding-stones were found amongst the _débris_. In the nearly-drained site of Loughavilly, the ‘Loch of the ancient tree,’ near Toppid Mountain, Co. Fermanagh, are the remains of a piled mound, formerly an island. Here were found a stone celt and lumps of iron slag. Traces of charcoal were abundant; but, from the softness of the