Traces of Roman settlements are particularly numerous in upper Alsace. _Germania prima_ and _secunda_ were not confined to the left bank of the Rhine: in the reign of Trajan, the Romans had extended the frontier to the line marked by the _limes_ running through a part of Nassau, across the Maine, and as far as the Alps. This _sinus imperii_ did not form a separate province, but belonged to Germania on the left bank of the Rhine, being one of those _provinciae Germaniae_, which had their own _praesides_. It was, on the whole, a favourite practice at that time to divide the power among several magistrates. BRITANNIA. Britain was known in the most remote times; but its name does not occur until the Macedonian period; it was previously designated by the name of _Cassiterides insulae_. The tin trade can be traced to a very early period; for the first attempts to smelt copper were made by mixing it with tin. The brass of the ancients, the real χαλκός, consisted for the most part of tin, and all the ancient Roman ases consist of copper and tin. Ὀρείχαλκος, from ὀρεύς, a mule, is something different (Messing), and the spuriousness of the mixture is indicated even by its name. A plentiful supply of tin is not found in any part of Europe, except Cornwall, whence it is quite certain that the name Cassiterides refers to Britain. The trade in it was carried on from Gades; but the Massilians had, no doubt, their share in it, as we may infer from the voyages of Pytheas. In the geography of Eratosthenes, the British islands are already mentioned in the plural; but before the time of Caesar, this part of the world was buried in great obscurity. Britain, like Gaul, was inhabited by the two nations, the Gael and the Cymri; but it is very difficult and problematical to draw the boundary line between the two. The north seems originally to have been occupied by Cymri, though, according to Tacitus, who in this matter also is a weighty authority, apparently with an admixture of Germans or Scandinavians. At present, the inhabitants in the west, from Cumberland down to Cornwall, so far as the ancient population is preserved, are Cymri; but we do not know whether these Cymri retreated to those parts during the conquests of the Angli and Saxons, or whether they had dwelt there even before. In Ireland nearly the whole population is Gaelic; the north, about Ulster, contains only feeble traces of Belgae or Cymri, and if this observation be correct, it is a proof of a conquest having taken place. From Ireland the Gaelic population spread into Scotland, but it is uncertain whether in this latter country they strengthened the Gael who already dwelt there, or whether they expelled tribes of the Cymri. These events belong to a comparatively recent period. The Picts, in the south-west of Scotland, unquestionably belonged to the Cymrian race.