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Description: | BAIRD & TATLOCK GLASGOW (stencilled in black on the bceramic base). MANU Baird & Tatlock Glasgow late 19th century 100, Sauchiehall Street, or 40, Renfield street, Glasgow, Scotland. This is a large demonstration magnetic compass needle on a stand.
It is widely supposed that the Chinese were the first inventors of the compass sometime in the 3rd century BC Ch'in dynasty. They found that a naturally occurring massive iron oxide, chemically Fe3O4, called lodestone or magnetite, had the 'magical' property of pointing to the magnetic poles if it was free to pivot. Curiously they used their instruments as south-pointers.
The Chinese were particularly interested, as an ancestor worshipping culture, in the orientation of buildings particularly tombs in order to maximise the suitability or chi of a particular site. Their compasses were at first used for geomancy, a form of divination, rather than navigation. They were comprised at first of a short handled spoon like object, which represented the constellation of the plough or big dipper. The whole object consisted of two boards, the lower one representing the earth and the upper, which was free to rotate, representing the heavens. Objects including the dipper were cast onto the boards in order that the geomancer could make his divinations. By the 1st century AD, in the H'an dynasty, the upper board had been dispensed with and the bowl of the dipper, now made of lodestone or loaded with a small piece of this material, sat on a bronze plate. The plate, which reduced the friction and allowed the short arm of the 'spoon' to act as the pointer, was marked with astrological symbols and zodiacal signs to designate the cardinal points.
By the end of the T'ang dynasty, in the 10th century AD, the Chinese had learned how to magnetise iron by rubbing it against a lodestone. Consequently they had substituted the incomparably more valuable lodestone with iron and the dipper had been reshaped into the more familiar needle. The compass, now of use to navigators, had a pointer which was set on a pin or which was floated on water.
During the Sung dynasty in the 11th century AD the compass needles were magnetised by heating them to a red heat and then allowing them to cool in the north south orientation. This fixed the Earth's magnetic field into their molecular structure. At the same time the Chinese began developing their international trade routes by sea and land, including the overland route known as the Silk Road. It is thought that the compass was introduced to Europe by this route early in the 11th Century.
The first european to write on the subject of magnetism was a soldier pilgrim self styled Peregrinus. Little is known of Peregrinus except that he was possibly a Frenchman born in Picardy at the village of Maharne-curia now Maricourt near PĂ©ronne in the department of Somme. However, it should be noted that identifying the birthplace of monastics and ecclesiastics at that time is problematic since more often than not they signed themselves with their Christian name and the name of the religious house to which they belonged. However, the name Maharne-curia suggests an ecclesiastic rather than monastic establishment.
After an academic career it is thought that Peregrinus became a Crusader in the army of the King of Sicily, Charles of Anjou (1225-1285). The name Peregrinus means pilgrim, a name often assumed by Crusaders. It is thought that he served as an engineer at the siege of the Lucera north west of Foggia, which at that time was the capital of Capatinata in the plain of Apulia near the Adriatic coast of Italy. When the town was eventually taken the mosque was converted into a cathedral. Here in 1269 he is supposed to have written the 'Epistola de magnete'. Roger Bacon (circa 1214-1292) the English philosopher called Peregrinus, whose work is among the first examples of modern scientific writing, "the Master of Experiments".
The first truly scientific document on magnetism "De Magnete" was published by William Gilbert in 1600. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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