** Specific gravity 8·59.
I have here given most of the trustworthy analyses already published, and have only added two new analyses kindly made for me by Mr. J. A. Phillips, F.G.S., of a socketed celt from Yorkshire and of a small dagger from Newton, near Cambridge.
Those who wish for detailed information as to the composition of the bronze antiquities found in other countries are referred to De Fellenberg’s essays and to Von Bibra’s comprehensive work.[1618]
The copper which was used by the bronze-founders of old times appears to have been smelted from the ore and run into a shallow concave mould open at top, in which the metal assumed the form of a circular cake, convex below and flat above; but before becoming sufficiently cold to be quite set into tough metal, these cakes seem as a rule to have been disturbed and broken up into numerous pieces, better adapted for re-melting than the whole cakes would have been. This method of breaking up the solid cakes while hot saved also an infinity of labour; as to cut such masses into small pieces when cold would, even with modern appliances, be a difficult task; and with only bronze and stone tools at command would have been nearly impossible. Many of the cakes are, however, interspersed with cavities formed in the metal, and in some cases there seems reason to think that this may have been produced intentionally, so as to render the breaking of the cakes even when cold more readily practicable.
Many of the blocks of metal cast in rough moulds, and known by Italian antiquaries as æs signatum, have a similar broken appearance at the ends. Professor Chierici[1619] has suggested that the moulds in which they were cast were of considerable length, and that from time to time clay and sand were thrown in so as to break the continuity of the metal, which indeed was poured in at intervals, after the insertion of the sand or clay, to form the break in the mould.
Some pieces of metal which have been regarded as ingots, and which not improbably are really such, have the form of a double-ended axe with a very small shaft hole. They have been discovered with several of the bronze-founders’ hoards in France. Dr. V. Gross, of Neuveville, has a fine example of this kind found at Locras, in the Lac de Bienne.[1620] It is about 16½ inches long and 4¾ inches wide at the ends, the hole through the centre being about ¼ inch in diameter, and the weight of the ingot, which is of pure copper, is about 6½ lbs.
Rough lumps of metal have frequently been found with deposits of bronze implements in Britain, these latter being sometimes in a worn-out or broken condition, and apparently brought together as old metal for re-casting. In other deposits the instruments seem new and ready for use, or again they are in an unfinished condition. All the circumstances of these discoveries, however, go to prove that they are in fact the stock-in-trade of the ancient bronze-founders. The jets or waste pieces from the castings, of which I shall subsequently have to speak, are often found mixed with the rude lumps. These lumps have usually the appearance of pure copper, and in many cases have proved to be so on analysis.
Some copper cakes appear, however, to belong to Roman times. They differ in shape from those already described, in being of nearly even thickness, but with the edge inclined as if they had been cast in a small frying-pan. They are from 10 to 13 inches in diameter and about 2 inches thick; and on more than one found in Anglesea[1621] there are inscriptions in Roman characters. They weigh from 30 to 50 lbs.
Turning now to the instances of lumps of rough metal being found with bronze weapons and tools, the following may be cited, though other instances are given in the tables at page 462:—