Page:Popular Science Monthly Volume 67.djvu/702

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
696
THE POPULAR SCIENCE MONTHLY.

Bronze, the alloy of copper and tin was the Egyptian's tool-steel, his cast and wrought iron—in short, all that iron and steel are to the American. Just when he discovered the effect of tin on copper there is no means of knowing, but certain it is that many centuries have passed since he came into the possession of the secret.

The presence of flint tools only, in the deserted mining camp in Wadi Maghara can not be used as an argument that bronze and iron tools were not then in use, for they are mentioned in inscriptions, pictured in paintings and sculptures and are found in tombs belonging to a period many centuries before the abandonment of the mines. In the time of Herodotus the Egyptians used both stone and metal cutting instruments. The use of bronze is mentioned in inscriptions antedating the Great Pyramids. Of the work of the first three dynasties, Rawlinson says: 'A metallurgy of no small merit must have formed and hardened the implements whereby materials such as those employed by the Egyptian builders and sculptors were worked with ease and freedom.'

Possibly the oldest piece of cast bronze whose age has been established is a knob from the scepter of Papi, a Pharaoh of the sixth dynasty (about 2500 B.C.). This and other bronzes of very great antiquity are in the British Museum. The Posno collection in the Louvre contains two statues which are believed by Perrot and Chapiez to date from the close of the Old Empire or the beginning of the Middle Empire (about 2300-2000 B.C.), but Erman says they are 'archaistic works of the twenty-sixth dynasty (about 650-525 B.C.). They are light, hollow and cast in one piece. The eyes and eyebrows were made of precious stones inlaid in the bronze. The technical skill and workmanship displayed are said to be extraordinary. A hollow cast statue of Ramses II., of excellent design and skilful workmanship, dates from about 1300 B.C.

In the inscriptions, several kinds of bronze are spoken of again and again, as, for example, 'bronze,' 'bronze in the combination of six' and 'black bronze.' These varieties contain the constituent metals in different proportions. A very common bronze, used for a variety of purposes, contains copper 85 per cent., tin 15 per cent.; another common bronze has the composition: copper 88 per cent., tin 12 per cent. A bronze used for weapons and cutting instruments is found by analysis to contain copper 94 per cent., tin 5.9 per cent, and iron.1 per cent. Without the iron, this would be the softest of the three, but the iron probably compensates for the lower percentage of tin. It is evident that the use to which the alloy was to be put determined the proportion in which the metals should be combined. This fact supports the belief that from very early times the metal workers used metallic tin in the manufacture of bronze, and, therefore, that they were familiar with the separation of tin from its ores. Bronze weapons of the composition mentioned above, were so skilfully tempered that, after the lapse of