GALILEO A PISA *

Roberto Vergara Caffarelli

(translated by Katiuscia Mariottini)

In 1992, both 350 years since Galileo's death and 300 years since he was conferred a chair at the University of Padua are remembered. The day has been celebrated with several events by the University to show what Galileo did in the Venetian Republic.

In 1592, when he left the University of Pisa, a period in Galileo's life was over, that of the drawing and initial flourishing of his most revolutionary scientific ideas. Yet, I have been teaching in the University of Pisa for more than twenty years and it seems to me that it is fair to talk about the "pisan period". In particular, I'll talk about Galileo's family, his adolescence, his registration to the faculty of artists where degrees in Philosophy and Medicine were conferred, his researches and first discoveries, and his writings: De motu in particular, which was probably written during his teaching in our University.

Galileo was born on February 15th¹ 1564, but this date is not totally certain. Yet, it is known that his baptism was celebrated on February 19th² . Fascinated from the idea of a wonderful coincidence with the day of Michaelangelo's death, it was thought that Galileo was born a day before. This tradition was followed by the University of Padua, which solemnly celebrated three hundred years since his birth on February 18th, 1864. Vincenzio, Galileo's only son was said to be born on the 19th of the same month, that is the day of his baptism³.

This must not wonder us, because even the most famous people did not know the exact day of their birth. The grand Duke Ferdinand I is an amazing example: needing to know the day of his birth, his wife, Christine of Lorena, asked Galileo to do an astrological research between two equally possible dates. After having drawn the astrological themes according to the dates suggested, Galileo answered on 16th January 1609 in Padua: "Comparing the events, it seems to me that it is fairest to believe that the most probable date is July 30th 1549, and surely not July 19th 1548. Therefore His Highnesses is now fifty-nine and not sixty years old"⁴.

It is necessary to know the exact day and time of his birth in order to reconstruct the sky's constellation and do the astrological computations so that one can know when Galileo was born. Several astrological documents about him have reached us, among which a good four "drawings/designs of the nativity" of Galileo. Some of them bear the date of February 15th, but all of them seem to concord. However, we must say that among his "astrological mess" as Favaro calls it, (he edited the national edition of Galileo's works) there is a note written by Galileo's hand which can be helpful to fix the day of his birth: "February 15th, 1564, 22:30". The time is done in the Italian way, that is, starting from the sunset. Below, one can read: February 15th, 4 p.m.: this second note indicates the same time, but starting from midday⁵. Favaro computed the equivalence of the two dates according to the latitude of Pisa (43^. 41') and added 10 days to convert it from the Julian calendar to the Gregorian, which (in 1582) dated the equinox to May 21st. Thus, he could check that the sunset was exactly at half past five p.m. Considering the hours from the sunset to the birth (10; 30 p.m.), exactly 4 p. m. of the day after are obtained.

Galileo's note, considering the way time was calculated in Italy, put off the day of the birth to the 16th of the same month. Then, one should add 10 days more, so, from the point of view of the present calendar, the celebration day should be on February 26th⁶.

His father, Vincenzio, had a fundamental influence on Galileo. He was born around 1520 at Santa Maria a Monte, a little town that had been for some time part of the district of Florence. His grandfather Michelangelo was born in the same place as well around 1478. His family was an aristocratic Florentine family, receiving the highest honour in the consulate in 1210, then a gonfalonier in 1446, and a good 18 members became priors. His great grandfather left Florence before 1480 because of economic reasons⁷. Having sold his own house in via delle Burelle- the present number 7- and some other properties he had in Florence, he bought a few houses and estates at Santa Maria a Monte. Lisabetta, one of his grandfather's sisters, had married one of the Ammanatis of Pescia, probably of the same family of Galileo's mother. It is interesting to notice that, as will Galileo always do, in an act of selling which has reached us, Galileo's grandfather put on evidence his father's provenance from Florence: Michelangelus Iohannes de Galileis de Florentia ad presens terreginus S. M. ad Montem⁸. Vincenzio always declared to be of Florence, and he was right if he referred to his nationality, but, if he meant a declaration of citizenship, he was wrong, because he had given it up. Galileo didn't have the citizenship of Florence⁹ either, and in November 1628, he beg the grand Duke, who exceptionally granted the favour. Nevertheless, it is said that Vincenzio came back to Florence when he was very young to dedicate himself to his music studies, and he became a great music theoretician, author of five works that he published¹⁰, 13 manuscripts and many musical compositions that have reached us.

It is known that Vincenzio went in Rome twice, where he met Girolamo Mei to talk about music; the latter wrote good words about him to Giovan Vincenzio Pinelli (19th May 1582). It is curious that Pinelli became one of young Galileo's friends and he put him up when he arrived in Padua in 1592.

Vincenzio was a habitué at Giovanni de Bardi's, a house always full of "the most famous men in the town", as his son Pietro wrote to Monsignor Pietro Dini (December 16th, 1634).

Vincenzio Galilei loved these prestigious meetings, where music practice and studies in music theory were mixed. During a lot of his eves, with the assistance of virtuous men, he tried to pick up the gist of Greek, Latin and more modern writings and he became a good judge of any type of music theory¹¹.

Therefore, Galileo's father was an intellectual, even if one cannot deny that he had worked in trade as well. We don't know when and why he came to Pisa. In fact, Colonel Giuseppe Bocca, a Pisan subject, declared in one of his notes on July 9th, 1564 he rented "our house situated in chiaso di Mercanti for a year starting from August 1st, 1564, for 12 golden scuds" to the Pisan¹² "Vincenti Galilei, a Florentine maestro of music ". Iacopo, that is Filippo del Setaiolo's son and canon of the Primazial¹³, was the guarantor of the contract.

On 5th July, four days before the contract, Vincenzio had married Giulia Ammannati. Her brother Leone promised a draught of 100 gold scuds. The Ammannatis were of Pescia, but they had been living at Pisa for a few tens of years. A list of accounts on the draught shows that Vincenzio received 3 golden scuds for school-fees from his sister-in-law Dorotea (after Leone's command) on November 10th. The contract with Bocca shows that Vincenzio should paid exactly 3 scuds rent six months after the contract. Therefore, the house in Via Mercanti was actually a school and not Galileo's native house.

After careful archive researches, Giorgio del Guerra alleged to have found the place where Galileo was born¹⁴. Galileo was born, in a house possessed by the Ammannati family next to the present law court in via Giusti. His grand-mother Lucrezia and his aunt Dorotea lived here, and probably Mr and Mrs Galilei lived here as well after their marriage, indeed, in the contract of marriage, Leone promised a year's provision. The fact that on March 21st 1566Vincenzio was a member of the fraternity of S. Guglielmo, a group of people of Florence, shows his almost continued presence at Pisa during the first two years of marriage.

Vincenzio had six or seven children. Probably the second (Benedetto) had a short life, The third (Virginia) was born in 1573, then another daughter (Anna) was surely dead in a short time, in 1575 her had Michelangelo, then Livia in 1578; perhaps he had also a seventh daughter (Elena). One can think that, having so many children, Vincenzio often came to Pisa and see his family, which was at Pisa until the end of 1574.

What does one know of Galileo's infancy at Pisa? Directly from him, nothing. Some information is provided by Vincenzio Viviani, who wrote Racconto istorico della vita del Sig. Galileo Galilei for Leopoldo de' Medici: "He began to show his intellect's brightness during the first years of adolescence, when, during his spare time, he constructed himself several instruments and little machines, imitating and reproducing in small size every artificial construction he saw, such as mills, jails, and any other vulgar machines as well. In case a construction lacked of a necessary part, he supplied it by inventing it himself, using whale bones instead of iron springs, or other things: when he needed something, he used his brain in order to make the construction work and he never left anything imperfect".

A shred of his family life is provided by a few letters written by Muzio Tedaldi of Florence, a custom officer of the town of Pisa, a friend of Vincenzio's, and his son Michelangelo's godfather. Sir Tedaldi was married to a niece of Giulia Ammannati's, and therefore became a relative of Vincenzio's.

On January 13, 1574, Muzio writes: "...I've received Galileo's schizzatoio and his ball, as well as the books for Sir Corvini. Everything will be carried as soon as possible, I gave Galileo five Liras to pay his teacher, regarding your LadyI'll do anything I can: if Lady Lucrezia wasn't sick, I'd like her staying in my house for a month. Anyway, there's no point in saying so. The child (Virginia) is so fantastic that she appears unbearable to those who are not used to her. Yet, I asked him to say what he needs, and I'll do what I can; since I'm always busy, I cannot do what my duty suggests, but I'll supply with my money".

In another letter, dated February 9th, 1574, one can read: "I think you won't receive any letter from Galileo during this trip, surely he won't write you before next Wednesday, since tomorrow is St William celebration day. Anyway, I can assure you that everybody is healthy and happy, including the child (Virginia), except for your wife. Galileo transformed a mask in a pair of slippers, he's happy.» In the letter Tedaldi added a list of figures, among which: "Galileo gave his teacher five Lias". It is worth to highlight "everybody is healthy and happy...except for your wife". Was it only her daughter's liveliness that made Giulia nervous? Was she ill? Was she depressed perhaps? What problems made Muzio think of putting her up for a month?

However, difficulties were soon overcome, as one can read in another of Tedaldi's letter s to Vincenzio (March 10th, 1574): "Your wife and everybody else home is fine and healthyWe are waiting for you".

Tedaldi¹⁵ shows that Giulia Galilei stayed at Pisa until the end of October. The date of the family reunion at Florence is shown in a letter of Tedaldi, dated January 4th, 1575: "I received your letters together with one to the Rettore, which I immediately gave him. I'm glad to hear that your wife, you your child, and the others are fine, that Galileo's talent as his knowledge of literature as well is improving, and that Virginia is growing up, because I love you all as I love myself, I see you as another myselfYour friend Muzio Tedaldi".

The biography of Galileo's infancy can be enriched by indirect information: for instance, one can ask oneself who Galileo's teacher was? What had he been learning until he was nearly eleven?

It is known that the Comune di Pisa always had a particular attention for teaching, choosing able teachers, generally of other towns. Teachers were nominated for three years by the Priors, during a reunion in the House of Priors, after three ballots in the presence of other judges of the town and dottori¹⁶.

There were only three teachers: magister grammaticae, magister scribendi, and magister abbaci. From October 1569 to April 1571 Antonio Leonardi of Castiglione had been teaching at Pisa, then his place was taken by Giacomo Marchesi of Piacenza (from May 1571 to May 1574). A little information about school activities is provided by some instructions given to Antonio Leonardi on June 18th, 1569: "During working days, students are compelled to stay for three hours in the morning and three hours in the afternoon at least on Mondays, Tuesdays, Wednesdays, and Thursdays, plus an hour lecture. On Saturdays, a student should lecture while others comment on, in order that any student lecture at least once. Moreover, at least three classes of students are needed: one composed of Epistolanti, one of Latin scholars studying all the rules and one of beginners, which studies the concordances and the first rule. The class of Epistolanti is compelled to present an epistle every day of the mentioned four. Two Latin texts are compulsory for Latin scholars. As for the beginners, it is the person who repeats that should remind the teacher to look after them and get him to prepare a general examination on Fridays. On Saturdays, beside the lecture, he should make them repeat some verses learned by heart"¹⁷.

During the activities of Saturdays, young students were obliged to act as teachers, so that they became used to discuss, contest, insist on a different opinion, let their own concept to be judged by other people. It is interesting that all the lessons were at the same time, all the three classes together in one room . It is worth to notice that Antonio Leonardi taught Greek as well¹⁸.

Galileo started a new period of stable residence at Pisa only at the beginning of September 1580, when he registered to University. Not too much is known of the six years from 1575 to 1580, which had a fundamental importance for his cultural background and forged his character. Viviani says: " when he was a teenage, he spent a few years in human studies with a well-known teacher of Florence, since his father could not give him better comforts, having a big family and a scarce fortune. Even though, he would like him to go and live in a boarding school: he knew that Galileo's passion and intellect would drive him to do things out of ordinary progress in any profession he would start. Yet, being aware of his conditions and wishing to overreach it, young Galileo decided to face the poverty of his destiny applying himself assiduously to his studies. Therefore, having studied the first class of Latin authors, he reached a deep erudition in humanities of himselfhe studied Greek as well, and he learned it not so bad: he used it later, in his deeper studies".

Was Galileo a self-taught man? Probably he considered himself like this, but one can recall that Galileo had probably his first spur towards independent studies from the excellent elementary and primary schools he attended till he was nearly eleven.

There is no doubt on the mediocrity of his teacher, as Viviani hints: Nicolò de Gherardini, who received many secrets from Galileo, describes him like this: " a rather ordinary man who used to teach in one of his own houses situated in Via de Bardi" and he calls him Jacopo Borghini da Dicomano.

In this period there is another rather obscure event: Vivani writes: "he received lessons of Logic from a priest of Vallombrosa, but learning all these dialectic words, definitions, differences, as well as a great quantity of writings was boring, fruitless: his wonderful intellect was not gratified".

Galileo's life in monastery is described by an Abbot of Saint Prassede monastery, Friar Diego Franchi of Genoa, in an abstract about illustrious religious men of Vallombrosa. The manuscript is kept in the Archive of Saint Mary of Vallombrosa: "Galileo Galilei was a famous man and an outstanding figure in mathematics: his name should not be forgotten. He was a novice in Vallombrosa, where he made his first intellectual practice. Pretending to see him to Florence in order to recover from a serious ophthalmy , his father kept him so long that he was diverted from religion"

A letter of Tedaldi (16th July 1578) appears to be referring to this fact: "I'm glad to know that Galileo is back with you, and that you'd like him to study here, but this will be a bad year, now it's time of harvest and one sack of wheat is valued 15 Lira: however, God knows, and will find a solution". A few months before, on April 29th, he had written: "I see from your letter what you've decided about your son. However, while you're waiting for an accommodation in the boarding school of Sapienza, you can let Galileo start his studies: in case you don't succeed in obtaining a place, I'll offer my house, with no charge, I promise you. "

Probably we will never know the reason, people or circumstances which drove Galileo to follow his inclination (which will be stopped by his father's intervention), but Vincenzio's reaction can be easily understood: he saw all his hopes about his first-born son suddenly disappear. Since there were no obstacles to a clerical career, and it was embraced by most first-born children, Vincenzio's act could be a sign that he sensed Galileo's capacities and talent even if he would like him to grow a doctor.

His father's endeavour to get him enter the boarding school of Sapienza fives the occasion for a farther consideration: had Vincenzio reached his goal, Galileo would have grown a good doctor, because surely he would get his degree , at least in order to avoid the reimburse of the boarding fees. Instead, things went differently and the great scientist found his way during five years of studies at the University of Pisa¹⁹.

I'll add some observations about the Collegio della Sapienza, founded by Cosimo on February 9th, 1543. It welcomed "all talented brains oppressed by the poverty of their families, who could not show their gifts in the studies and the nobility of their nature"²⁰. It opened in 1544, with 30 students, in the following year it received the rent of "houses and shops situated at Pisa, along the way which start from the Ponte di Mezzo on the Arno river and ends at the Fortress in Via de' Setaioli. They were of public property, but were demolished to improve the view on the Arno so the customs of Pisa was charged with the costs of the boarding school".

We know that "the request for admission had been repeatedly presented indeed for five or six years, which was the period that the statute of the Studio established to get a degree. Those who retired from school or were expelled because of any reason and did not get their degree in the established period had to return what he had received during the years of stay²¹ ... Very strict rules were followed about the students' clothes: they must wear a very long black tunic, provided with a black hood on their left shoulder, applied by a hook".

On September 5th, 1580, Galileo registers to University²². This crucial date concludes the strict biographical notes