More efficient couplers
Since the domestication of the horse, men knew that it was fast and stronger than the ox. However, this animal was rarely used for fieldwork, as the harness was not suitable for heavy pulling. The traditional harness consisted of a loose handcraft carried on the animal's neck. Also, the more the horse pulled, the more the tinker obstructed his breathing. In the early Middle Ages, the rigid collar harness was invented. This padded necklace rested on the horse's shoulders and did not interfere with his breathing. The performance of the couplers was also improved by changing the position of the draught animals. In ancient times, two, four, sometimes six horses were harnessed side by side in front of a tank. The strength of these horses was poorly concentrated and partly lost. In the Middle Ages, they were harnessed in line, or in pairs, so the horses exerted a much greater force. In hot and dry climates, the horses' hooves wore relatively little. They were protected by bandages called hipposandals. On the other hand, in the temperate and heavy climates of central Europe, the hooves were reinforced with iron nailed underneath. Shoeing was one of the innovations that helped to make the horse the indispensable auxiliary of man. In addition, the arched saddle improved the rider's stability, especially in the longitudinal axis (forward-backward), it increased his ability to maneuver, especially in armed clashes. The Barbarians from the East brought the stirrup in the 9th century. Connected to the saddle, the stirrups provided a strong support point, increasing lateral stability. The warrior could wear spears and stand on the stirrups during a fight.
The mill
The rediscovery of the water mill
The current industrialized world is facing a serious problem: energy. Until a few years ago, oil seemed sufficient to satisfy ever-increasing needs. Since then, we have become aware of the depletion of resources. A similar problem arose during the 11th century. Indeed, most of the energy available to man was provided by the animal. The revival of economic activity created an urgent need for new energies. In ancient times, the great empires had a huge mass of slaves, so the question of energy was never raised in a crucial way. But the decline of slavery in the medieval world led men to rediscover and spread a very old invention: the watermill. It is thought that the first water mills were known in the Eastern countries, Greece and the Roman Empire as early as the 1st century BC. Around the 9th century, mills spread rapidly in France. The principle of the water mill is relatively simple. The force of the water flowing or falling from above sets a large wheel in motion. Gears transmit this movement to a stone wheel which, moving on a fixed stone, grinds the cereals into flour. From this basic principle, ingenious devices made it possible to operate much more complex mechanisms.
Applications of the water wheel
A hub of the water wheel connected to a turnstile equipped with buckets, made it possible to bring up to the surface the water from flooded wells or mines. This allowed unproductive dry land to be irrigated and unexploited mines to be reactivated.
This is a much more complicated application of the hydraulic system. A worker makes wire. The coarsely worked metal is forced through small holes. Sitting on a swing, the worker grabs the wire that comes out of the hole with large pliers. The swing is connected to a crank-operated by the water wheel, the worker is carried forward and then back along the axis of the crank. During the backward movement, it is enough for him to hold the wire with the clamps to pull it by force. This example shows an important technical progress since the circular movement of the wheel is transformed into a back and forth movement.
Another decisive advance for the artisanal and industrial use of hydraulic energy occurred when away was invented to transform the circular movement of the wheel into a rectilinear movement in the vertical direction. This is the camshaft: protruding corners on the shaft connected to the wheel, rotating regularly, raise and lower the tool that does the work.
In the first example, large, heavy rammers, falling down, broke the ore needed for the smelter.
In the second example, the camshaft actuates a very heavy hammer-pilon which forms the spongy mass of the molten iron and, ridding it of slag (residues), transforms it into steel.
These industrial uses explain why the mill was for a long time synonymous with manufacturing and is still synonymous in the English language (mill).
The miller's mill
The seigneurial mill: The oldest and most widespread of the mills was the miller's mill, where farmers used to grind wheat and other cereals. The lords forced their serfs to grind the grain, against payment, in the seigneurial mill (or banal mill) and punished those who used handwheels. The use of the mill spread and the miller's house became one of the main meeting places for village life.
The windmill: At that time, the miller's mills were still hydraulic. But the Middle Ages used another source of energy: the wind. The use of the windmill became necessary in arid and windy environments. It has been known for a very long time, especially in Asia. The principle of its operation and applications are practically the same as those of the watermill. The driving force is produced by the wind, which rotates wings connected to the central shaft. The most important technical advance occurred when the upper part of the mill was placed on a rotating platform. In this way, the wings were oriented according to the wind direction.
Technical progress in navigation
The medieval great trade benefited from the progress made in the construction of ships and the appearance of new navigational instruments. The most important innovation was the diffusion of the compass. Its origin remains uncertain: if the Chinese had known it for a long time, it was perhaps the Arabs who introduced it to Europe, unless it had been rediscovered by Western sailors or astronomers. The magnetic needle that was simply floating on the water or oil at first was then fixed on a pivot to turn the compass in all directions. Sailors could now face the high seas without fear of making a wrong course. In addition to the compass, the astrolabe (Arabic instrument) was used to measure the height of the stars above the horizon. By accurately calculating the time spent sailing, it was possible to accurately determine the distance the vessel had traveled north or south (latitude), east or west (longitude). Taking advantage of these improvements, the Genoese were the first at the end of the 13th century to link Italy by sea to Flanders and England. At that time the typical ship was the galéasse. This galley moved mainly under sail. The appearance of the triangular Latin sail, which could be oriented in all directions, allowed the ship to sail in crosswinds and even against the wind. The stern rudder, fixed by hinges in the middle of the ship's after deck (stern rudder), replaced the long and heavy lateral oars, improving maneuvering. The rotating yoke (cross-support of the sail) allowed the square sails to be oriented to the side in the wind. On some sailboats, a second mast at the front was beginning to appear.
to be continued in the next part