100 NATURE 
[Marcu 28, 1912 
In consequence of this mode of heating, the lower 
parts of the crucible will, it is evident, bear but little 
traces of the action of a high temperature, whilst 
the upper edges and interior will exhibit a fused or 
semi-fused structure, and this is precisely what we 
find in all early crucibles. 
Some of the most important types of crucibles are 
illustrated in Fig. 1. 
The small capacity of by far the greater number 
of these crucibles which have been found is worthy 
of note. Few can have held more metal than would 
suffice for the casting of a single axe. This is, how- 
ever, not surprising if we remember that they are 
the appliances of that remote time when metallic 
Weapons were only beginning to replace those of 
stone. : 
The moulds used by primitive man are also of con- 
siderable interest. The earliest are of the class known 
as open moulds, and consist merely of cavities of the 
necessary form and size hollowed in the surface of a 
stone. 
In casting swords and daggers of bronze the moulds 
must have been of clay and been heated to dull red- 
ness at the time when the metal was poured in—a 
method of casting which is still practised in Japan— 
as by no other means could such perfect castings of 
their thin blades have been obtained. The castings 
generally were hammered at the cutting edges, and 
it is to this hammering, and to it only, that the hard- 
ness of the cutting edges of both copper and bronze 
Weapons is due, and not to any method of tempering. 
Much has been written about the so-called art of 
tempering bronze supposed to have been practised 
by the men of the Bronze age in the manufacture 
of their weapons; the hardness is also said to be 
greater than can be given to bronze at the present 
day. I should like to correct this error, as it can 
only have arisen owing to its authors never having 
made any comparative practical tests of the hardness 
of bronze. Had they done so, they would have found 
that the ordinary bronze of to-day can be made as 
hard as any, in fact, harder than most, of prehistoric 
times, by simple hammering alone. 
We will now pass to the consideration of the copper 
alloys of Mycenzean, Babylonian, Greek, and Roman 
times. Until the introduction of iron, copper and 
bronze played an important part in the lives and 
struggles of the early races occupying the Greek 
peninsula and its islands, whilst in later times the 
alloy bronze afforded an imperishable material to the 
great sculptors of the golden age of Greece, by which 
many of their incomparable works have been pre- 
served to us. 
In Greek literature we have no records of metal- 
lurgical processes relating to copper or its alloys, 
such as are to be found in the writings of Roman 
authors, notably Pliny. 
Strabo, the only Greek author who condescends to 
take any notice of metallurgy or metal worling, 
confines his statements to gold, silver, and lead. But 
at Laurion the remains of ancient furnaces for smelt- 
ing lead ores, which have been unearthed from time 
to time, indicate that low hearths resembling those of 
the Bronze age were extensively emploved; and if we 
may reason from Japanese metallurgical procedure, 
similar furnaces would be used for copper. The 
island of Cyprus, once rich in copper ores, was doubt- 
less the source whence the inhabitants of the Greelx 
peninsula in early times obtained their copper. 
Among the earliest specimens of the metal which 
have been found in Greece are some copper nails 
which were obtained by Dr. Schliemann at Orcho- 
menos, a city in Beeotia, which was in a state of decay 
in the time of Homer. Thev belong to that remote 
NO. 2213, VOL. 89] 
period in Mediterranean civilisation to which the name 
Mycenzean has been applied. 
They are interesting as showing that the men of 
that remote period were able to produce copper of 
tolerable purity, but this would not be difficult, as the 
ores which they worked would be oxidised ores, 
oxides, and carbonates from the outcrops of veins, 
viz. the parts which were exposed at the surface of 
the ground. 
Bronze was also then in use for nails and cramps 
in building construction, but especially for weapons, 
and was of good quality. 
There is abundant evidence to show that Egypt 
was the first in the field in artistic bronze casting. 
When it first began it is difficult to say, but objects 
of at least as early as 3000 B.C. are in existence. 
Even in the early examples great technical skill is 
displayed. The most ancient Greek bronzes are solid 
castings, whereas in Egypt they are light and hollow, 
having been cast with a core of argillaceous sand, 
which still remains in many specimens. 
The statuary bronze frequently contains consider- 
able amounts of lead, sometimes with but little tin, 
and the question naturally suggests itself, whether 
this arose from scarcity of the latter metal. Only 
a few analyses have been made, and unfortunately 
few of the objects can have even approximate dates 
assigned to them. 
Bronze was in extensive use in Nineveh about 
1000 B.c. for vessels and utensils of many kinds, and 
curiously was sometimes employed for those which 
we should now make of more precious metals. 
The Greek copper alloys of a later period, many 
examples of which are found in the coins of about 
the fourth century B.c., are true bronzes consisting of 
copper and tin, with lead or zinc only as impurities 
and not intentionally added. 
A curious feature in them is the presence of nickel 
varying from traces up to 05 per cent. The per- 
centage of tin is somewhat irregular, but in most 
examples ranges from about 8 to 11 per cent. The 
same is true of the Macedonian coinage alloys from 
the third to the second century B.c., but the per- 
centage of tin in them is somewhat greater, generally 
being from about 10 to 12 per cent. These alloys 
were undoubtedly made by melting together the 
metals copper and tin, and not, as in the Bronze 
age, by smelting stanniferous copper ores, or by melt- 
ing copper with tin ore. 
The Macedonian alloys more particularly are the 
best of the ancient bronzes. 
A little later in Greek coins we find lead as an 
intentional constituent in various proportions, ranging 
generally from about 6 to to per cent., or even more, 
with a proportionate reduction in the percentage of 
tin. The Macedonian coins, however, with few ex- 
ceptions, preserve their character as true bronzes. 
The alloys used for statues are frequently true 
bronze with 9 to 11 per cent. of tin, but in other 
examples about 5 per cent. of lead has been added, 
probably with the intention of increasing the fusibility 
of the alloy and its fluidity when molten. 
The statements of Pliny as to the composition and 
mode of manufacture of the bronzes as imitated in 
Rome throw but little or no light on the sub- 
ject; in fact, they are for the most part useless and 
misleading. As regards the Corinthian bronze, the 
beauty of which is so extolled by classical writers, he 
states that the alloy was discovered by the Romans 
at the sack of Corinth, when vessels of gold, silver, 
and bronze had been accidentally melted together 
during the burning of the city and produced a golden 
bronze. ci 
The siege of Corinth, however, occurred in 146 B.c., 
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