pounds of ore ; when they are filled they are covered with lids and smeared
with lute.
In Eisleben and the neighbourhood, when they roast the schistose
stone from which copper is smelted, and which is not free from bitumen,
they do not use piles of logs, but bundles of faggots. At one time, they used
to pile this kind of stone, when extracted from the pit, on bundles of
faggots and roast it by firing the faggots; nowadays, they first of all
carry these same stones to a heap, where they are left to he for some time in
such a way as to allow the air and rain to soften them. Then they make a
bed of faggot bundles near the heap, and carry the nearest stones to this
bed; afterward they again place bundles of faggots in the empty place
from which the first stones have been removed, and pile over this extended
bed, the stones which lay nearest to the first lot; and they do this right up to
the end, until all the stones have been piled mound-shape on a bed of faggots.
Finally they fire the faggots, not, however, on the side where the wind is
blowing, but on the opposite side, lest the fire blown up by the force of the
wind should consume the faggots before the stones are roasted and made soft ;
by this method the stones which are adjacent to the faggots take fire and
communicate it to the next ones, and these again to the adjoining ones, and
in this way the heap very often burns continuously for thirty days or more.
This schist rock when rich in copper, as I have said elsewhere, exudes a
substance of a nature similar to asbestos.
Ore is crushed with iron-shod stamps, in order that the metal may be
separated from the stone and the hanging-wall rock.8 The machines which
miners use for this purpose are of four kinds, and are made by the following
method. A block of oak timber six feet long, two feet and a palm square, is
laid on the ground. In the middle of this is fixed a mortar-box, two feet and six
digits long, one foot and six digits deep ; the front, which might be called a
^Historical Note on Crushing and Concentration of Ores. There can be no
question that the first step in the metallurgy of ores was direct smelting, and that this
antedates human records. The obvious advantages of reducing the bulk of the material to
be smelted by the elimination of barren portions of the ore, must have appealed to metallurgists at a very early date. Logically, therefore, we should find the second step in
metallurgy to be concentration in some form. The question of crushing is so much involved
with concentration that we have not endeavoured to keep them separate. The earliest
indication of these processes appears to be certain inscriptions on monuments of the IV
Dynasty (4,000 B.c. ?) depicting gold washing (Wilkinson, The Ancient Egyptians, London,
1874, 11, p. 137). Certain stele of the xu Dynasty (2,400 b.c.) in the British Museum
(144 Bay 1 and 145 Bay 6) refer to gold washing in the Sudan, and one of them appears to
indicate the working of gold ore as distinguished from alluvial. The first written description of the Egyptian methods—and probably that reflecting the most ancient technology
of crushing and concentration—is that of Agatharchides, a Greek geographer of the second
Century b.c. This work is lost, but the passage in question is quoted by Diodorus Siculus
(ist Century B.c.) and by Photius (died 891 A.D.). We give Booth's translation of
Diodorus (London, 1700, p. 89), slightly amended: " In the confines of Egypt and the
" neighbouring countries of Arabia and Ethiopia there is a place full of rich gold mines,
" out of which with much cost and pains of many labourers gold is dug. The soil here
" is naturally black, but in the body of the earth run many white veins, shining like
" white marble, surpassing in lustre all other bright things. Out of these laborious
" mines, those appointed overseers cause the gold to be dug up by the labour of a vast
" multitude of people. For the Kings of Egypt condemn to these mines notorious
" criminals, captives taken in war, persons sometimes falsely accused, or against
" whom the King is incens'd; and not only they themselves, but sometimes all their
