These conical vessels are probably earlier in date than the spheroidal caldrons.
Whether either were actually manufactured in Britain and Ireland is an interesting question. There can, I think, be little doubt that the conical form originated among the Etruscans, whose commerce certainly extended to the northern side of the Alps.[1600] One of the upright vases found at Hallstatt[1601] has animal figures upon it almost undoubtedly of Etruscan work, though showing some signs of Eastern influence in their style, and bronze helmets bearing Etruscan inscriptions have been found in Styria. On the other hand, M. Alexandre Bertrand and some other antiquaries are inclined to believe in a more direct commerce with the East along the valley of the Danube or Dnieper. The finding of vessels of the same form in Brittany, England, and Ireland seems to point to a more western course of trade, always assuming that these objects were imported. That some of them may have come from abroad appears in the highest degree probable. Not impossibly the æs importatum of Cæsar may refer to a continuance of such a trade. But whether there were no bronze-smiths in the British Isles capable of imitating such products of skill is doubtful. The bronze shields which are of essentially indigenous character exhibit an amount of dexterity in producing thin plates of bronze quite sufficient for the manufacture of such vessels. Moreover, the handles of these British and Irish vessels are formed by rings, while those of the vessels from southern countries are loops like the handles of pails or buckets. The spheroidal caldrons are also of a form and character which appears to be unknown on the Continent, and are therefore, in all probability, of indigenous manufacture.
The careful manner in which some of the vessels are mended affords an argument that such utensils were rare and valuable; but it also shows that the native workmen understood how to make thin plates—unless these were portions of other vessels—and at all events how to rivet plates together.
CHAPTER XXI.
METAL, MOULDS, AND THE METHOD OF MANUFACTURE.
Having now passed in review the various forms of weapons, tools, ornaments, and vessels belonging to the Bronze Period of this country, it will be well to consider the nature of the metal of which they are formed, and the various processes by which they were produced and finished ready for use. Some of these processes, as for instance the hammering out of the cutting-edges of tools and weapons, and the production of ornamental designs by means of the hammer and punch, have already been mentioned, and need be but cursorily noticed. The main process, indeed, of which this chapter will treat is that of casting.
Bronze, as already stated, is an alloy of copper and tin, and therefore distinct from brass, which is an alloy of copper and zinc. Many varieties of bronze—or, as it is now more commonly called, gun-metal—are in use at the present day; and one remarkable feature in bronze is that the admixture with copper of the much softer metal tin, in varying proportions, produces an alloy in most if not all cases harder than the original copper; and when the tin is much in excess, as in the metal used for the specula of telescopes, so much harder that, à priori, such a result of the mixture of two soft metals would have been thought impossible. The following table compiled from a paper in Design and Work, reprinted in Martineau and Smith’s Hardware Trade Journal,[1602] gives some of the alloys now in most common use and the purposes to which they are applied:—