Great discoveries

One calls Grandes discoveries the geographical discoveries which marked the western world with, as certain “inventions” of the same time which allowed these voyages or which were the result.

Representations of the world before the great discoveries

In Antiquity

One owes the first chart with the Ionian school, which gathers, with Milet, the philosophers physicists concerned about the observation of the Nature. Among these philosophers, Anaximandre (610-547 AEC) is the first which traces a total and coherent chart known grounds.

But, in the time of Homère, one believed that the ground was punt, rectangular or circular. Anaximandre lent to the ground the shape of a drum, and even a thickness gave him.

Parménide of Élée (Eleatic school), thought to him that the ground was spherical, theory which convainquit not philosophers of the Ionian school.

From Plato (428-348 av J. - C.)), one generally admits, in the ancient Greece, that the ground is spherical. Plato presents it like motionless and being used as pivot with the entire universe. Eratosthène gave an almost exact estimate of its ray.

Aristote (384 front J. - C. - 322 front J. - C.), Posidonios, Hipparque and the large later philosophers of the ancient Greece adopted the thesis of Parménide and Plato.

It is thus seen that Plato and Aristote, in spite of their philosophical divergences, in common had the spherical representation of the ground, which was that of the traditional period of the ancient Greece.

Hérodote still believed that the ground was punt.

Only the Astronome Aristarque de Samos (310, Ca 230 avJC) suggested that the ground could rotate and around the sun.

One can reproach, neither with Plato, nor with Aristote, to have been unaware of the respective movement of the Earth and the sun, since they lived both before Aristarque de Samos.

In the top the Middle Ages

At the 6th century, Cosmas of Alexandria seeks to show that the ground was, not spherical as claimed it the Greek philosophers of the period traditional, but punt and rectangular.

In bottom the Middle Ages, starting from the XIIe century

Before XIIe century, the most widespread representation of the world in occident was thus very summary: one represented the ground like punt.

Some Explorateur S of the Moyen-âge believed in the existence of mythical countries that they sought. Most known was the Royaume of the priest Jean, whom one located in Ethiopia, and which was a Christian kingdom located behind the grounds Musulman be: this kingdom will be the object of many Exploration S. Moreover, the West comprises many mythical connotations, it would be about the country of gold or the anteroom of the Paradis.

This mythical universe is found in the fact that Francisco de Orellana, seeing women drawing with the arc, named the river close which they lived the the Amazon.

One finds traces of the search for a biblical Eden , in accordance with certain aspects of the abrahamic Religion, until the 16th century, for many explorers with the long course in the big wides of the Pacific Ocean, with the research of the mythical kingdom of the King Solomon, that the legends allot chimerical richnesses. This gives the baptism of the the Solomon Islands, according to the observations of Álvaro de Mendaña.

Following the first Crusade S, and under the influence of the erudite philosopher and Albert Large the (between 1193 and 1206 - 1280), and of the philosopher Roger Bacon (1214 - 1294), a movement took shape in favor of a return to a spherical design and a scientific knowledge of the Ground. One then integrated this knowledge in the European first Université S, which were created at the end of the XII {{E}} and at the beginning of the 13th centuries, with the other sciences transmitted starting from the to know Islamic, very advances some in the field of the Astronomie and the Géographie, for religious reasons.

At the 15th centuries, the Connaissance S general and geographical accumulated then considerably in Occident: spherical design of the ground and philosophy (Plato, Aristote), Cartography and Geography (Ptolémée), returns of the first great voyages (Marco Polo).

Actually, one at that time did not make the difference between the Géographie, the Cosmographie, and the Astronomie.

The arrival of the Imprimerie in occident at the 15th century (1453) accelerated considerably the diffusion of the works of cosmography and cartography.

The frame of reference employed by the large navigators included:

general knowledge brought by the philosophers of the ancient Greece, not very reliable on the purely geographical level (being given the seniority of these philosophers: IVe century before J. - C.), but interesting in the field of the observation of nature,

dimensions of the ground evaluated by Eratosthène, almost exact, whereas those of Ptolémée were sullied with certain errors,

the Geography of Ptolémée, redécouverte at least at the 12th century: she affirmed that the Earth is round. This work will be the reference many navigators. However, the Geography of Ptolémée comprised an error: an erroneous calculation places Asia at the longitude of the Mexico, which explains partly the error of Christophe Colomb when it arrived to America,

the works of the large Arab astronomer Al-Farghani (IXe century), which also made authority.

the mine of geographical information brought back by the missionaries franciscains Guillaume de Rubrouck, sent of Saint-Louis to the court of large Khan of Mongolia,

geographical information coming from the voyages of Marco Polo in China (to go by ground, and return by sea), and the information of the existence of the island of Cipango, i.e. of Japan,

the Imago mundi of the cardinal Pierre d' Ailly, written towards 1410, and printed in 1478, reference to the 15th century (Christophe Colomb had a specimen of it),

the first Globe carried out by Martin Behaim in 1491.

All in all, the cultivated world was thus perfectly aware that the ground was spherical (round) since approximately. However:

It is probable that the less cultivated classes still believed in the 15th century that the ground was punt (to the 16th century in Japan, François Xavier brought the information of the rotundity of the ground),
One did not know of course the existence of the America (nor of the Oceania),
One imagined that the whole of the emerged grounds was in the northern Hemisphere, in a sector of 180° approximately in Longitude, according to the voyage of Marco Polo to the return of the Asia by sea. One thus did not imagine the southern part of the Africa which is in the southern hemisphere,
contours of the continents were still rather vague, as well as the evaluation of the distances.

Should finally be noted the very important influence that probably had in the Western company, the information brought back by the English knight Jean de Mandeville, which went on a journey in Far East during 34 years, of 1322] to 1356, i.e. into full Guerre One hundred Year old. This explorer wrote on his return of voyage the Livre of the wonders of the world, also starting from the accounts of the explorers missionaries franciscains and Dominican (in Latin). The Livre of the wonders of the world was diffused with 250 specimens in various vernacular languages), in a company which was not yet largely aware of the possibilities of circumnavigation and owing to the fact that the ground was spherical.

The Livre of the wonders of the world of would Jean de Mandeville be the precursor of the Mondialisation?

Conditions of the great discoveries

Religious requirements

At the 15th century, the idea of Reconquista is very strong in the Iberian peninsula: the grounds conquered on the Infidels are divided between the colonists. However, at the 15th century, there are no more grounds to colonize on the continent: it thus becomes necessary to find others of them. The catch of Constantinople by the Turks in 1453, raises great concern in the Christian world; Rome encourages the Portuguese thus to leave to discover the coasts of Africa in order to find a passage towards the south to join " Indes" that one believed Christian.

Economic pressure

The economic pressure pushes the men to discover new grounds. Thus, all the grounds of culture of Canne to sugar are occupied in Europe, it is thus necessary to find other grounds. In the same way, the money mines of Bohemia tend to become exhausted, one hopes to discover new territories comprising of the mines. Lastly, the trade of spices is under the monopoly of Venice: one thus seeks new roads to gain India in order to compete with it.

Technical innovations

Innovation S techniques are developed without which the Great discoveries would not have been possible like the Gouvernail of stern post. Long and manoeuvrable ships are invented: the caraque one or the caravel. The Caraque is a ship which can transport much goods, which comprises four masts and a castle with before and one with the back; most famous is the Santa Maria of Christophe Colomb. The caravel is a ship much smaller.

Objects of measurement to facilitate navigation are developed: the Compass, the Charts (Portulan S) and the Astrolabe S. Mercator succeed in making charts punts which represent the curved surface of the ground by respecting the angles.

Portuguese discoveries

The exploration of the African coasts

At the 14th century, the Portuguese occupy Madeira, the Azores, the Canaries which they lose at the 15th century. Thanks to the prince Henri the navigator (1397 - 1460) which brings together many scientists, these colonies are recovered and the exploration of the African coasts starts. This exploration is facilitated by the discovery of the principle of the Volta i.e. of navigation using the dominant winds. In 1441, natives are captured, transported and put in slavery, it is the beginning of the Traite blacks. In 1460, the Guinea is reached and the Portuguese have the monopoly of the African trade which includes/understands gold, ivory, slaves and Malinguette (African substitute of pepper). An agreement between the king and the tradesmen takes place: the latter have the monopoly of the trade in exchange of the continuation of explorations for Portugal. In 1475, the Ecuador is crossed: the navigators are surprised by the changes of the winds and the sky. In this context, Cabral drift at the time of Volta and discovers the Brésil in the neighborhoods of 1500. In 1488, double Bartolomeu Dias the Cape of Good Hope.

The road of the Indies

After the discovery of America, the Portuguese want to discover another Route of the Indies: they send two explorers, one by overland route, Covilha and the other by sea, Vasco de Gama. This one will sail round Africa and will open the road of the Indies in 1498. With its continuation, Pedro Alvares Cabral, Francisco de Almeida and Alfonso de Albuquerque draws up solid fulcrums: Zanzibar, Calicut, Malacca. Charts of the coasts and winds are also developed and make it possible to the navigators to travel with the seasons.

The discoveries Castilians

The discovery of America

The round the world tour

Magellan wants to sail round America and to join the Indies by the west. It encounters a refusal of the Portuguese always privileging the African road but obtains the support of Charles Quint. The departure takes place the August 10th 1519 with five ships. In 1520, the Magellan Strait is crossed after one year spent in the gulf of Rio of Plata. During the crossing of the Pacific, Magellan is killed in Philippines the April 27th 1521: Sébastian El Cano replaces it and charges with spices. It regains Spain continued by the Portuguese: it arrives at Seville the September 4th 1522. It does not remain any more that only one ship and 247 men out of 275 died. However, the spices refund 400% of the expenses of the voyage. The Traité of Tordesillas is re-examined because it does not take account of the rotundity of the ground. A fictitious line is traced on the Moluques: what is in the east is Spanish and in the west is Portuguese; it is about the Traité of Saragossa in 1529.

Chinese discoveries

cf 1421, the year when China discovered America Gavin Menzies (editions Intervalles, Paris, 2007 for the translation)

Random links: