This, he points out, is a more fusible alloy than the ordinary plumbers’ solder, which consists of 1 of tin to 2 of lead, and fuses at 441 degrees Fahr., as it contains nearly 4 of tin to 1 of lead, and would fuse at 365 degrees. Whether this bar was intended for use as solder, or represents a base tin exported to Scotland from the tin-producing districts, is an interesting question. Professor Daniel Wilson[1650] has called attention to the fact that in all the bronze instruments found in Scotland which have been submitted to analysis lead is uniformly present, though in varying proportions. Soldering[1651] is considered to have been entirely unknown in the Bronze Age, and even during the earlier times of the Iron Age; but the art of burning bronze on to bronze was certainly known, and instances of its having been practised are given in preceding pages.
Some fragments of pure metallic tin have from time to time been found on the Continent. A small hammered bar found at the Lake-dwelling of Estavayer,[1652] and analyzed by M. de Fellenberg, was free from lead, zinc, iron, and copper.
Besides being found in Cornwall, tin occurs in France,[1653] Saxony, Silesia, Bohemia, Sweden, Spain, and Portugal. It also occurs in Etruria,[1654] and is said to be found in Chorassan.[1655]
This metal is said by Dionysius[1656] to have been struck into coins at Syracuse, but none such are at present known. Among the Ancient Britons,[1657] however, tin coins cast for the most part in wooden moulds were in circulation, not in the tin-producing districts, but in Kent and the neighbouring parts of England. Their date is probably within a century of our era, either before or after Christ.
Fig. 514.—Falmouth. 1/12
A large ingot of tin, in shape like the letter H, was dredged up in Falmouth harbour.[1658] It is 2 feet 11 inches long and about 11 inches wide, and 3 inches thick, and, though a small piece has been cut off at one end, it still weighs 158 lbs. It is shown in Fig. 514. The late Sir Henry James, F.R.S.,[1659] has pointed out that the form in which the ingot is cast adapts it for being laid in the keel of a boat, and for being slung on a horse’s side, two of them thus forming a proper load for a pack-horse. He has also suggested that this was the form of ingot in which the tin produced in Cornwall was transported to Gaul, and thence carried overland, as described by Diodorus Siculus, to the mouths of the Rhone. Curiously enough this author speaks of the blocks being in the form of astragali, with which this ingot fairly coincides. Other ingots[1660] of tin of different form have also been found in Cornwall, but there appears to me hardly sufficient evidence to determine their approximate date, and I therefore content myself with mentioning them. A lump cast in a basin-shaped mould, with two holes in the flat face converging so as to form a V-shaped receptacle for a cord, is in the Blackmore Museum at Salisbury.
What appear to be ingots of copper rather than votive or mortuary tablets have been found in Sardinia,[1661] and in their form present a close analogy with this ingot of tin, though they are of much smaller dimensions. Both the sides and ends curve inwards, the notch at the ends of some being semicircular. They are counter-marked with a kind of double T.
As to the method of melting the metal but little is known. It seems probable, however, that the crucibles employed must have been vessels of burnt clay provided with handles for moving them; while for pouring out the metal small ladles of earthenware may have been used. At Robenhausen,[1662] on Lake Pfäffikon, Switzerland, small crucibles of a ladle-like form have been found, in some cases with lumps of bronze still in them. Crucibles without handles have been discovered at Unter-Uhldingen,[1663] in the Ueberlinger See.