COPPER AND ITS ALEOYS IN EARLY 
TIMES.* 
ITH the discovery of metals, and notably the 
application of copper and its alloys in Neo- 
lithic times, we have one of the great turning points, 
if not the greatest, in the history of human “develop- 
ment, the first-birth of the germs of that civilisation 
and culture to which we have attained at the present 
dav. The discoveries of the properties of steam and 
electricity and their applications to our industries and 
other practical purposes of life we are apt to regard as 
wonderful and epoch-making, yet when we compare 
them with the results which have followed the dis- 
covery of metals, they are but trifling and insig- 
nificant. 
The order in which the metals were discovered was 
not the same for every region, as their ores are very 
capriciously distributed in the world, and it is ex- 
tremely probable, if not absolutely certain, that the 
metals which occur native, i.e. those which occur as 
metals in nature, must have been first known to the 
men inhabiting the localities in which they occurred. 
The metals so occurring most frequently are gold and 
copper. The former is much more widely distributed 
than the latter, and must have been the first metal to 
be known in many regions. 
It is, however, one of the most worthless metals 
for practical purposes, so that until the rise of Greek 
and Roman civilisation but little use was made of it. 
Copper, too, we only find in use to a very limited 
extent, as it was not well suited for the construction 
of weapons or useful implements. On the other 
hand, its alloy with tin afforded a metal which in 
many physical properties could only be surpassed by 
iron or steel. According to the views of several 
ancient writers, Lucretius and Poseidonius, so momen- 
tous a discovery as that of metals contained in ores 
must needs have been brought about by no uncommon 
cause. 
According to them a conflagration consumed forests 
which covered the outcrop of metalliferous veins, 
reducing the metals and bringing them to the notice 
of man, but there are no grounds for such inference. 
The discovery of metals other than “‘native’’ had no 
such poetic origin, but was brought about in a more 
commonplace and more humble way. It had its 
origia in the domestic fires of the Neolithic age. 
The extraction of the common metals from their 
ores does not require the elaborate furnaces and com- 
plicated processes of our own days, as pieces of ore, 
e‘ther copper carbonate or oxide, cassiterite, cerusite, 
or mixtures of these, and even iron oxides which by 
chance formed part of the ring of stones enclosing 
the domestic fire, and became accidentally embedded 
in its embers, would become reduced to metal. 
The camp fire- was, in fact, the first metallurgical 
NATURE 
aft 
[Marcu 28, 1912 
The alloys of copper and tin during the early Metal 
age, and even somewhat later, were obtained not by 
melting together copper and metallic tin, but by the 
reduction of oxidised copper ores containing tin-stone, 
or of copper ores to which tin-stone was ‘added. As. 
it has been stated by several Continental archzeologists 
that when a copper ore containing tin ore is smelted 
the tin does not enter into combination with the 
copper, but passes into the slag, I have made several 
experiments under the conditions which were available 
to prehistoric man, which completely disprove their 
statements. 
A furnace of the simplest form, merely a hole in 
the ground, was constructed in my laboratory at the 
Royal School of Mines. The fuel used was charcoal. 
A mixture of copper ore (green carbonate) and tin- 
stone was smelted in it, and a copper-tin alloy, a 
bronze containing 22'0 per cent. of tin, was obtained. 
The experiment was repeated several times, and in 
every case copper-tin alloys were obtained. This 
experiment proves indisputably- that when a copper 
ore containing tin ore was smelted by primitive man, 
a bronze consisting of copper and tin was the result. 
The shape and structure of the lumps of copper 
which have been found in the founders’ hoards? of 
the Bronze age afford valuable evidence as to the size 
of the rude smelting furnaces, the method of smelt- 
ing, and the manner in which the metal was removed 
from the hearth. These lumps are always fragments 
of rudely disc-shaped cakes of about 8 in. to Io in. 
in diameter, and 1} in. in thickness, having the 
largely columnar fracture of copper when broken near 
its solidifving point. They show that the furnace was 
simply a small shallow hole or hearth scooped in the 
ground, about to or 12 in. in diameter, and that the 
operation of smelting must have been conducted as 
follows :—A small charcoal fire was first made in the 
hearth, and when this was burning freely a layer of 
ore was spread over it, and upon this a layer of 
charcoal, then alternate layers of ore and charcoal 
' were added in sufficient quantity to yield a cake of 
furnace, and from it, by successive modifications, the | 
huge furnaces of the present day have been gradually 
evolved. 
First, a shallow cavity would be formed in the 
hearth of the fire for the reception of the molten 
metal, and this would be made larger as time went 
on and larger quantities of metal were required bv 
deepening it or by surrounding it with a higher wall 
of stones. Furnaces of precisely this primitive form 
survived in Derbyshire up to the seventeenth century. 
In Japan the furnace for smelting copper, tin, and 
lead ores, a mere hole in the ground, which was in 
universal use there up to 1858, and is still extensively | 
employed, is as simple and rude as that of the men 
of the Bronze age. 
1 Abridged from the See Address to the Institute of Metals by 
Prof. William Gowland, F.R 
NO. 2213, VOL. 89] 
copper. The fire was doubtless urged by the wind 
alone in the earliest times, but later by some kind of 
bellows. 
When all the charge had melted, the unburnt char- 
coal and the slag were raked off. The metal was 
not laded out, but was allowed to solidify first, and at 
the moment of solidification was rapidly pulled out and 
the cake broken up at once on a large stone. In 
Korea, at the copper mine of Kapsan, this primitive 
method of removing the copper from the furnace still 
survived when I travelled through the country in 
1884. 
The method of smelting copper ores in the primi- 
tive furnace which has survived in Japan from pre- 
historic times closely resembles that of the Bronze 
age. The copper of the Bronze age resembles modern 
blister copper in composition, but, unlike it, it often 
contains only traces of sulphur. When sulphur is 
present in the crude metal only in traces it un- 
doubtedlv indicates that the metal had been obtained 
by smelting oxidised ores. The percentage of copper 
in several characteristic specimens ranges from about 
970 to gg°o. 
I will now ask for your attention to the earliest 
alloys of copper and tin, those of the Bronze age. 
In the production of these alloys in the earliest part 
of the age, copper ores containing cassiterite can 
alone have been used; it is obvious, therefore, that 
2 Founders’ hoards, many of which have been unearthed in this country 
and in Europe, contain generally worn out or broken implements, waste 
castings, and rough lumps of copper apparently hrought together for 
recasting. In some the objects are new and ready for, use or are in an 
unfinished state. They appear to have been the steck-in-trade of itinerant 
fonnders. A flat axe made of the alloy is in the British Museum. 
