Stories of Useful Inventions

by S. E. Forman

In the course of time man learned how to make his implements and weapons of metals as well as of stone. It is generally thought that bronze was the first metal to be used and that the "stone age" was followed directly by the "bronze age," a period when all utensils, weapons, and tools were made of bronze (Fig. 2). It is easy to believe that bronze was used before iron, for bronze is made of a mixture of tin and copper and these two metals are often found in their pure or natural state. Whenever primitive man, therefore, found pieces of pure copper and tin, he could take the two metals and by melting them could easily mix them and make bronze of them. This bronze he could fashion to his use. There is no doubt that he did this at a very early age. In nearly all parts of the world there are proofs that in primitive times, many articles were made of bronze.

If primitive man were slow to learn the use of iron it was not because this metal was scarce, for iron is everywhere. "Wherever, as we go up and down, we see a red-colored surface, or a reddish tint upon the solid substances of the earth, we see iron—the bank of red clay, the red brick, the red paint upon the house wall, the complexion of rosy youth, or my lady's ribbon. Even the rosy apple derives its tint from iron which it contains."[8] But although iron is so abundant it is seldom found in its pure or natural state. It is nearly always mixed with other substances, the mixture being known as iron ore. Primitive man could find copper and tin in their pure state but the only pure iron he could find was the little which fell from heaven in the form of meteors, and even this was not perfectly pure for meteoric iron is also mixed slightly with other metals.

The iron which lay about primitive man in such abundance was buried and locked tightly in an ore. To separate the iron from the other substances of the ore was by no means an easy thing to do. Iron can best be extracted from the ore by putting the ore in a fire and melting out the iron. Place some iron ore in a fire and if the fire is hot enough—and it must be very hot indeed—the iron will leave the ore and will gather into a lump at the bottom of the fire. To separate the iron from its ore in this way is to make iron. When and where man first learned the secret of making iron is of course unknown. A camp-fire in some part of the world may have shown to man the first lump of iron, or a forest fire sweeping along and melting ores in its path may have given the first hint for the manufacture of iron.

Iron making at first doubtless consisted in simply melting the ore in an open heap of burning wood or charcoal, for charcoal is an excellent fuel for smelting (melting) ores. But this open-fire method was wasteful and tedious and at a very early date the smelting of the ore was done in a rude sort of a furnace. A hole ten or twelve feet deep was dug in the side of a hill. In the hole were placed charcoal and iron ore, first a layer of charcoal, then a layer of the ore. At the top of the mass there was an opening and at the bottom there were several openings. When the mass was set on fire the openings produced a good strong draft, the charcoal was consumed, and the ore was smelted. The product was a lump of wrought iron, known as the bloom.

FIG. 4.—BELLOWS WORKED BY THE FEET.

The hillside furnace worked well enough when the wind was favorable, but when the wind was unfavorable there was no draft and no iron could be made. So ironmakers found a way by which the air could be driven into the furnace by artificial means. They invented the bellows, a blowing apparatus (Fig. 3) which was usually made of goat skins sewed together and which was operated either by the hands or by the feet (Fig. 4). Sometimes the bellows consisted of a hollow log in which a piston was worked up and down (Fig. 5). After the invention of the bellows, ironmakers could make their iron whenever and wherever they pleased, for they could force air into their furnaces at any time and at any place. This rude bellows forcing a draft of air into a half-closed furnace filled with a burning mass of charcoal and iron ore was the first form of the forge, one of the greatest of all inventions.

With the invention of the forge the stone age gradually passed away and the iron age was ushered in. Tools and weapons could now be made of iron. And great was the difference between iron tools and stone tools. To cut down a tree with a flint hatchet required the labor of a man for a month, while to clear a forest with such an implement was an impossible task. But the forge gave to man iron for the sharp cutting tools, for the ax and knife and chisel and saw. With these he became the master of wood and he could now easily cut down trees and build houses and make furniture and wagons and boats.