Inventions in the Century

by William Henry Doolittle

That copper and tin combined would make bronze was a more complex proceeding and probably followed instead of preceding, as has sometimes been alleged, the making of iron tools. That bronze relics were found apparently of anterior manufacture to any made of iron, was doubtless due to the destruction of the iron by that great consumer—oxygen.

What was very anciently called “brass” was no doubt gold-coloured copper; for what is modernly known as brass was not made until after the discovery of zinc in the 16th century and its combination with copper.

Among the “lost arts” re-discovered in later ages are those which supplied the earliest cities with ornamented vessels of gold and copper, swords of steel that bent and sprung like whalebones, castings that had known no tool to shape their contour and embellishments, and monuments and tablets of steel and brass which excite the wonder and admiration of the best “artificers in brass and iron” of the present day.

To understand and appreciate the advancements that have been made in metallurgy in the nineteenth century, it is necessary to know, in outline at least, what before had been developed.

The earliest form of a smelting furnace of historic days, such as used by the ancient Egyptians, Hebrews, and probably by the Hindoos and other ancient peoples, and still used in Asia, is thus described by Dr. Ure:

“The furnace or bloomary in which the ore is smelted is from 4 to 5 feet high; it is somewhat pear-shaped, being about 5 feet wide at bottom and 1 at top. It is built entirely of clay. There is an opening in front about a foot or more in height which is filled with clay at the commencement, and broken down at the end of each smelting operation. The bellows are usually made of two goatskins with bamboo nozzles, which are inserted into tubes of clay that pass into the furnace. The furnace is filled with charcoal, and a lighted coal being introduced before the nozzle, the mass in the interior is soon kindled. As soon as this is accomplished, a small portion of the ore previously moistened with water to prevent it from running through the charcoal, but without any flux whatever, is laid on top of the coals, and covered with charcoal to fill up the furnace. In this manner ore and fuel are supplied and the bellows urged for three or four hours. When the process is stopped and the temporary wall in front broken down the bloom is removed with a pair of tongs from the bottom of the furnace.”

This smelting was then followed by hammering to further separate the slag, and probably after a reheating to increase the malleability.

It will be noticed that in this earliest process pure carbon was used as a fuel, and a blast of air to keep the fire at a great heat was employed. To what extent this carbon and air blast, and the mixing and remixing with other ingredients, and reheating and rehammering, may have been employed in various instances to modify the conditions and render the metal malleable and more or less like modern steel, is not known, but that an excellent quality of iron resembling modern steel was often produced by this simple mode of manufacture by different peoples, is undoubtedly the fact. Steel after all is iron with a little more carbon in it than in the usual iron in the smelting furnace, to render it harder, and a little less carbon than in cast or moulded iron to render it malleable, and in both conditions was produced from time immemorial, either by accident or design.

It was with such a furnace probably that India produced her keen-edged weapons that would cut a web of gossamer, and Damascus its flashing blades—the synonym of elastic strength.

Africa, when its most barbarous tribes were first discovered, was making various useful articles of iron. Its earliest modes of manufacture were doubtless still followed when Dr. Livingstone explored the interior, as they now also are. He thus describes their furnaces and iron: “At every third or fourth village (in the regions near Lake Nyassa) we saw a kiln-looking structure, about 6 feet high and 2½ feet in diameter. It is a clay fire-hardened furnace for smelting iron. No flux is used, whether with specular iron, the yellow hematite, or magnetic ore, and yet capital metal is produced. Native manufactured iron is so good that the natives declare English iron “rotten” in comparison, and specimens of African hoes were pronounced at Birmingham nearly equal to the best Swedish iron.” The natives of India, the Hottentots, the early Britons, the Chinese, the savages of North and South America, as discovery or research brought their labours to light, or uncovered the monuments of their earliest life, were shown to be acquainted with similar simple forms of smelting furnaces.