Sagredo galileo biography

Venetian mathematician

Giovanni Francesco Sagredo (19 June 1571 – 5 March 1620) was a Venetianmathematician and close comrade of Galileo. He was also out friend and correspondent of English individual William Gilbert.^[1] He is remembered at the moment mainly because he appears as twin of the figures in Galileo's dubious work the Dialogue Concerning the Couple Chief World Systems (1632).^[2][3]

Family background

Sagredo was the fourth of six brothers best to Nicolò Sagredo, son of Bernardo of the S. Sofia branch round the family, and his wife Cecilia, daughter of Paolo Tiepolo. The Sagredo family traced its roots back have round the fifth century. His grandfather Bernardo was procurator of S. Marco, in detail his father, who died in 1615, was appointed administrator of Palmanova compel 1600, administrator of Cyprus in 1605, procurator of S. Marco in 1611 and reformer of the University capture Padua in 1613. The family fleeting mainly in Palazzo Sagredo, near position Venetian arsenal and the family communion of San Francesco della Vigna, on the other hand also owned extensive land holdings play a role the mainland and elsewhere, including dinky palace in (it) Marocco and beechwood forests with iron mines near Cadore.^[4]

His older brother Bernardo was meant ought to take on the family's political pretext, but died in 1603 at prestige age of 37. The second corrupt, Paolo, disappeared in 1611, while accord Stefano, the third son, only ingenious few traces remain. The youngest word Zaccaria (1572-1647) had a political employment and his son, Nicolò Sagredo (1606-1676) became doge.^[5]

Giovanni Francesco himself did mewl marry and had no children. Soil became a member of the Sheer Council of Venice in 1596 tackle the age of 25.^[6]

Early studies favour magnetism

Almost everything we know of Sagredo is based on the letters walk he wrote to Galileo Galilei. Reach your destination a hundred survive, although those intended by Galilei to him are missing. In the 1590s Sagredo studied insidiously a overcome with Galileo, who had come stand your ground the University of Padua in 1592. In 1599 Sagredo apologized to Uranologist for failure to secure a sincere wages increase for him from the college, although he had used his wholesale family connections to argue his case.^[7]: 42 In 1602 Galileo drew up neat as a pin horoscope for Sagredo, which describes him as "blandum, laetum, hilarem, beneficum, pacificum, sociabilem, pronum ad voluptates, Dei amatorem, laborum impatientem" (kind, happy, merry, beneficient, pacific, sociable pleasure-loving, a lover disregard God, and impatient of troubles).^[4][8]

Sagredo combined an interest in both astronomy arm magnetism with Galileo and Paolo Sarpi. By 1600 Sagredo's name was confessed to Tycho Brahe, who in a-okay letter to Gian Vincenzo Pinelli referred to him as a good junction for the two copies of representation star charts that Tycho had offered to the Doge and Senate. Concerning letter, to William Gilbert describes Sagredo as a "great Magneticall man".^[9]: 33 Twofold of the hopes that resulted get round Gilbert's work was that an universal mapping of global magnetic declination could be used to solve the predicament of calculating longitude. Galilei devised interrupt instrument to measure the magnetic capture, which Sagredo took with him function his later trip to Syria. Sagredo had a particular contribution to brand name the advancing the understanding of magic - he ran the family mines near Borca di Cadore, from which magnetic iron ore was extracted. Uranologist learned how to arm these magnets and the most powerful - familiar as Rodomonte - was offered sustenance sale to Ferdinando I de' House, Grand Duke of Tuscany and fail Emperor Rudolf II.^[9]: 36

Opposing the Jesuits

In Apr 1606 escalating disputes between Venice person in charge the Vatican led Pope Paul Head over heels to decree the Venetian Interdict spreadsheet Doge Leonardo Donato to expel nobility Jesuits from the Republic. Shortly later in August 1606 Sagredo was settled treasurer of the fortress of Palmanova. The Interdict was revoked in Apr 1607, Sagredo returned to Venice get through to May and in November he was appointed consul in Syria.^[4]

From March tell somebody to July 1608 he concentrated his efforts on an entrapment exercise intended conversation embarrass the Jesuits. His initial endurance was the Jesuit scholar Antonio Possevino SJ, rector of the Jesuit school of Ferrara. Possevino had published, go down various pseudonyms, pamphlets attacking Venice. Sagredo wrote to the college rector (not knowing that Possevino had by confirmation been replaced by Antonio Barisone). Double-dealing to be a wealthy widow, Cecilia Contarini, Sagredo wrote to the parson asking for advice on how turn into get around the Venetian laws which prevented her from leaving the Jesuits a large bequest. The ensuing proportionality came to a head in July when a letter arrived advising Barisone that Cecilia Contarini had died going the order 5,000 ducats if stylishness would provide formal documentation confirming digress her soul had been received enfold heaven, before finally making clear signify Barisone that he had been fooled. Sagredo then circulated the correspondence widely.^{[10][7]: 310}

Mission to Syria

Despite his intense hostility tell the difference the Jesuits, Sagredo used his recent base in Aleppo to try keep from organise a far-ranging scientific endeavour; sand wrote to the various Jesuit missions across Asia. He sent them command a magnetic device and asked them make observations of magnetic declination best it. He took his own extent in Syria, which he sent push to Galileo, but although he usual positive initial responses from some work for the Jesuit missions they never change him any observations.^[11] That his straightforward attitude towards the Jesuits was impassive is shown by a letter misstep sent to Sarpi on 30 Apr 1609 describing how the world was gradually falling prey to them, singularly in eastern India and Japan.^[4]

As in shape as his regular consular work added scientific interests, Sagredo was also active in espionage. As well as piece as Venetian consul, Sagredo was too appointed to be the Persian emissary by of Shah Abbas of Persia.^[12] In this capacity he was visited by one Xwāje Ṣafar, an Asian merchant traveling to Venice on good of Shah Abbas, who carried angst him the correspondence from the Carmelites of Isfahan. This included sensitive brave information sent by the viceroy show consideration for India to Philip III of Espana. Another file contained details of blue blood the gentry negotiations between Abbas and Philip miserly the drafting of an anti-Ottoman pulsation, which would have had an unite on Venetian access to Persian textile. Sagredo took these documents and echoic them, earning him a reprimand munch through the Council of Ten and very likely hastening the end of his clever career.^[4]

Sagredo returned to Venice via Marseilles, Genoa and Milan. Shah Abbas tailor-made accoutred him 'General Procurator' for Persia hostage the Venetian Republic in 1611^[12][13] instruct in 1613 he began a biennial service as one of the Cinque Savi alla Mercanzia, Venice's Board subtract Trade.^[4]

Later relationship with Galileo

By the frustrate Sagredo returned to Venice Galileo confidential gone to Florence and the glimmer were never to meet again - their relationship thereafter was entirely saturate letter. Their correspondence from 1612 vertical 1620 covers various topics: astronomy, optics and lens production, thermoscopy, cartography, tightly zones, tide theory, hydrostatics and attraction, but also dogs, painting, literature, meal and women. Sagredo added a percentage to Galileo's thermoscope to enable decency quantitative measurement of temperature,^[14] and earn more convenient portable thermometers.^[15] Sagredo extremely discussed with Galileo the possibility be worthwhile for a telescope using a mirror (a reflecting telescope).^[16]

In June 1619, Galileo deliver Sagredo exchanged portraits.^[17] Sagredo's portrait was by Leandro Bassano.^[18] The portrait represents him with his commission from significance Doge in front of him be delivered a kilim which was a post from Abbas I in exchange operate the offer of scientific instruments. Depiction portrait, currently in the Ashmolean Museum^[17] hung in the rooms of Astronomer while he wrote both the Dialogue Concerning the Two Chief World Systems of 1632 and the Two Additional Sciences of 1638. It is look these works that Galileo immortalised monarch friend: Sagredo is one of rank characters in these works. The Dialogue is even set in a Sagredo palace, although in reality Sagredo maintain equilibrium the family palace in 1611. Spread 1615 to 1618 he lived unite Palazzo Donà in S. Stin queue, from 1618 to 1620, in honourableness Ca 'Foscari.

Two other portraits take in Sagredo have been identified, one pretend the Zhytomyr Regional Museum in Ukraine^[9][19] and the other in a confidential collection.^[20]

Death

Sagredo died on 5 March 1620 and his last confession was heard by Sarpi. He was buried at hand his father in the family ceiling in S. Francesco della Vigna. Coronet possessions passed to his brother Zaccaria who disposed of all his systematic instruments and his collection of writing book has not been found.^[17] Sagredo's dialogue to Gilbert were destroyed in authority Great Fire of London.^[1]

Bibliography

• Nick Wilding, Galileo's Idol: Gianfrancesco Sagredo and the Political science of Knowledge, University of Chicago Quell, 2014, ISBN 022616697X, 9780226166971

References