We see that the peoples named forged their weapons and tools from very different alloys; pure copper at one extreme, bronze with 20 per cent. tin at the other. Experience had everywhere taught them that copper and bronzes poor in tin are too soft, while bronzes with an excess of tin could not be used for weapons and tools on account of being too brittle. They had also learned that lead and zinc considerably lessened the strength and tenacity of weapon bronze, while small quantities of iron, nickel, and cobalt are, at least, not injurious. So all races, although we can prove that they tried very different mixtures, finally adopted very simple and tolerably constant alloys. The bronze weapons of all countries frequently contain from 6 to 16 per cent. of tin, but usually between 8 and 12, with slight contamination of iron and nickel. Few nations have allowed lead to be used, fewer yet some zinc. For casting, the oldest races used the same kind of bronze as for weapons and tools. In many cases a few per cent. of lead were added to make the casting easier. The Romans used zinc in addition to lead in large quantity as a constituent of their alloys, and they made old bronze, bronze-brass, and brass. Afterward many nations of middle Europe used zinc alloys. Small quantities of iron, nickel, and cobalt are found for well known reasons in nearly all bronzes as harmless impurities. Traces of _sulphur_ are also found in them. This injures the quality of the alloy, and discloses the fact that such bronzes were not made from pure oxide ores, but from those containing sulphur pyrites. At the time when such bronzes were produced the mines had probably reached a considerable depth. Some of the weapon bronzes made by the ancients contain traces of _phosphorus_, an element as important in hard bronze as carbon is in steel. CASTING THE ALLOYS. The Semito-Hamitic races made excellent castings at a very early date. The Phoenicians may be mentioned as particularly skillful. It is reported that there were two immense bronze pillars that stood before the temple of Gades in the 11th century before Christ. The Tyrian founders also made a pillar for Solomon's Temple, and a metallic basin 10 ells in diameter and 5 deep. Similar large basins have been dug up in Assyria. The art of casting statues is no less ancient. Small statuettes were cast solid; larger ones consisted of several pieces which were riveted together. In the later Grecian and old Roman days the art reached a high stage of perfection. Many cities had thousands of bronzes; gigantic pieces were constructed. The Colossus of Rhodes was 30 meters high and stood with outstretched legs astride the entrance to the smaller harbor. Ships could pass through it with sails extended. A statue of Jupiter in Tarent was 20 meters high, and one of Nero was erected in Pliny's time, 30 meters high, costing a million dollars.[18] These facts give us a good idea of the technical ability of the old founders of bronze.