CHAPTER IV.
THE PROTO-CHALCITIC OR COPPER AGE OF WEAPONS.
I will begin by noticing that the present age has settled a question which caused much debate, and which puzzled Grote (ii. 142) and a host of others half a century ago, before phosphor-bronze was invented. This was the art of hardening (not tempering) copper and its alloys. All knew that these metals had been used, in cutting the most refractory substances,[156] granite, syenite, porphyry, basalt, and perhaps diorite,[157] by the ancient Egyptians, Assyrians, Trojans, and Peruvians. But none knew the process, and some cut the knot by questioning its reality. When you cannot explain, deny—is a rule with many scientists. The difficulty was removed by the Uchatius-gun,[158] long reported to be of ‘steel-bronze,’[159] but simply of common bronze hardened by compression. At the Anthropological Congress of Laibach[160] (July 27–29, 1878), Gundaker Graf Wurmbrandt, of Pettau, exhibited sundry castings, two spear-heads and a leaf-shaped blade of bright bronze (Dowris copper) adorned with spirals to imitate the old weapons. They were so indurated by compression that they cut the common metal.
Again, at the Anthropological Congress of Salzburg (August 8, 1881), Dr. Otto Tischler, of Prussian Königsberg, repeated the old experiment, showing how soft copper and bronze could be hardened by the opus mallei (simple hammering). Moreover his metal thus compressed could cut and work the common soft kinds without the aid of iron or steel. He exhibited two bronze plates in which various patterns had been punched by bronze dies. The hammering, rolling, beating, and pressing of copper for the purpose of hardening are well known to modern, and doubtless were to ancient workmen. The degree of compression applied is the feature of the discovery, or rather re-discovery.[161]
It may be doubted whether old Egypt and Peru knew our actual process of hydraulic pressure, whose simplest form is the waterfall. But they applied the force in its most efficient form. The hardest stones were grooved to make obelisks; the cuts were filled with wedges of kiln-dried wood, generally sycomore; and the latter, when saturated with water, split the stone by their expansion. And we can hardly deny that a people who could transport masses weighing 887 tons[162] over a broken country, from El-Suwan (Assouan) to Thebes, a distance of 130 miles, would also be capable of effecting mechanical compression to a high degree.
Buffon (‘Hist. Nat.’ article ‘Cuivre’) believed in the ‘lost art.’ Rossignol[163] (pp. 237–242) has treated of the trempe (διά τινος βαφῆς) que les anciens donnèrent au cuivre; and relates that the chemist Geoffrey, employed by the Comte de Caylus, succeeded in hardening copper and in giving it the finest edge; but the secret was not divulged. Mongez, the Academician, held that copper was indurated by immersion and by gradual air-cooling, but that la trempe would soften it.[164] In 1862 David Wilson, following Proclus and Tzetzes, declares the process of hardening and tempering copper so as to give it the edge of iron or steel, a ‘lost art.’ Markham[165] supposes that the old Peruvians hardened their copper with tin or silica; and he erroneously believes that tin is scarcely found in that section of South America.
Modern archæological discovery has suggested that in many parts of the world we must intercalate an age of virgin Copper between the so-called Stone and Bronze Periods. The first metal, as far as we know, was the stream-gold, washed by the Egyptians; and, as Champollion proved, the hieroglyphic sign for Núb (gold) is a bowl with a straining-cloth dripping water.[166] The fable of glass-discovery by the Sidonians on the sands of the Belus,[167] a tale which has le charme des origines, explains, I have said, how a bit of metalliferous stone, accidentally thrown upon the fire in a savage hut, would suggest one of the most progressive of the arts. And soon the ‘featherless biped,’ like the Mulciber and the Mammon of Milton—
Ransack’d the centre, and with impious hands
Rifled the bowels of their mother earth
For treasures better hid.