Marcu 28, 1912] 
NATURE 
99 
the percentage of tin they contain must have varied 
with the percentage of cassiterite in the ore and the 
regularity with which the smelting operations were 
performed. Even in the later period of the Bronze 
age, when the alloys were made by smelting the 
copper ore with cassiterite, alloys of definite composi- 
tion can only have been accidentally obtained. 
Further, it is very questionable whether the 
metal tin was ever employed in making the 
alloys until the Iron age was well advanced, 
as this metal has never been found in the 
founders’ hoards. Consequently the imple- 
ments and weapons are of very varied com- 
position, at first generally containing but 
little tin, less than 3 per cent., but later 
having that metal frequently in satisfactory 
proportions for the uses they were intended 
for. 
A curious feature of the alloys of which 
the early weapons were made in Hungary is 
the presence of antimony as an important 
constituent instead of tin. This doubtless 
arose from the alioys having been prepared 
by smelting the antimonial copper ores which 
occur in that country. Axes made of these 
allovs would be fairly serviceable on account 
of the hardness produced by antimony in 
copper. We hence find them in use, with 
antimony largely replacing tin, until late in 
the Bronze age. 
The difficulties the earliest men had to con- 
tend with were extremely great, for it is self- 
evident that alloys of definite composition 
could not be ensured by the early practice of 
smelting mixtures of ores. It would seem, 
therefore, that when we find weapons or 
implements of suitable composition for their 
intended use, some physical tests must have 
been applied to the furnace product before 
it had been used for their manufac- 
ture. 
We will now pass to a brief consideration 
of the methods followed by prehistoric man 
for the manufacture of his weapons and 
implements. Practically all copper celts were 
cast in open moulds, as if cast in closed 
moulds they would be more or less vesicular 
and worthless, except when the copper con- 
tained arsenic, tin, antimony, zinc, or niclxel 
in not less proportions than 1 per cent., or 
an excess of cuprous oxide. The remains of 
his appliances which have been found show 
clearly that the metal from the smelting 
operation was remelted.in crucibles and 
poured from them into moulds of clay or 
stone, perhaps of sand, but of this there is 
no definite evidence. The metal was not 
laded from the smelting furnace, as the small 
crucibles with rude handles which have 
occasionally been found, and have been 
erroneously supposed to be ladles, show no 
signs of having been exposed to a high 
temperature both on the inside and outside, 
as would have been the case had they been 
so used; the interior and upper edges alone 
bear marks of such exposure. The reason for 
this will be seen later. 3 
Implements and weapons of bronze, unlike those of 
copper, were always cast in closed moulds. The 
method of melting the metal in each case was as 
follows :—The furnace or hearth was merely a shallow 
depression in the ground. The crucibles were made 
of clay, which was sometimes mixed with finely cut 
straw or grass. They were embedded in the ashes at 
NO. 2213, VOL. 89] 
| the bottom of the hearth in such a manner that their 
| bases and sides were thoroughly protected from the 
intense heat of the fire, their upper edges and interior 
only being exposed. This method had been adopted 
owing to the fusible character of the clay of which 
they were made. The fuel used was wood and the 
charcoal which was produced during the 
process. 
Fic. r.—Prehistoric crucibles.—1. Clay vessel found among the débris of pile dwellings in 
Carniola. 
widely distributed in the remains representing the early Bronze age in the pile 
dwellings of Switzerland, the J)anubian basin, and Ireland. 
socket for the insertion of a stick, by which it was removed from the fire and its 
contents poured into a mould. 
found in the Mond See. 4 
Ireland. 
spear-heads and other iron objects. 
bronze implements and stone moulds in Mercia and Almeria, in the south-eas 
of Spain. 
It is open to doubt whether this is a crucible or nor. 2. A common form 
It is furnished with a 
3- Ashallow oval dish of somewhat rare occurrence, 
Found in the remains of a crannog in Lough Mourne, 
5, 6, 7; 8, a. Crucibles found at Dunadd, Argyll, together with iron 
ro and 11 were found together with copper i 
After a crucible had been thus placed and charged 
with copper, copper and tin-stone, or copper and tin, 
the fire was made up over it. A sufficiently high 
temperature for melting the metal could be obtained 
by the wind alone. When the contents of the crucible 
had melted, the crucible was removed from the furnace 
and the metal poured into a mould. 
