From an early age he assumed various positions of authority in the city, becoming a member of the Council of Elders, tribune of the people, and standard-bearer of justice.
[1] An efficient government man and an educated scholar, Marsili was a member of several academies, including the Gelati, the Notte and the Torbidi.
[3] In another letter of 7 July 1626, Marsili reported that a Bolognese artisan had succeeded in manufacturing a mirror that could produce the effects of a telescope, but that it had not yet been possible for him to verify its working.
[1] As prominent member of the ruling families in Bologna, Marsili played a key role in the appointment of Bonaventura Cavalieri to the chair of mathematics at the University, vacant since the death of Magini, in 1617.
There was no shortage of candidates, including Kepler, who politely declined, doubting the freedom he would enjoy at Bologna as a Protestant heliostaticist.
Thanks to the lobbying undertaken by Marsili, Galileo was highly regarded in Bologna, and he was a patron of Cavalieri, who was a pupil of his associate Benedetto Castelli.
[4] Marsili's friendship proved invaluable to Galileo in the preparation of his great work Dialogue Concerning the Two Chief World Systems.
Marsili undertook to obtain a copy of it, and took part in the discussions Galileo held with his friends to work out the main lines of his counter-argument.
The marble sundial created some five decades previously by Ignazio Danti[6] on the facade of Santa Maria Novella[7][8] did not in fact align with the sun at the equinox.