ALFANI, GUIDO. — Born in Florence on 17 January 1876 to Prof. Augusto, a member of the Accademia della Crusca, and Luisa Carobbi; he died there on 20 November 1940. He became a Scolopian on 10 May 1899. In 1905 he succeeded Fr. Giovannozzi as director of the Ximenian Observatory of Florence, which he made known throughout the world for its seismological activity. He was a distinguished seismologist and an ingenious experimental physicist. He perfected and devised numerous highly sensitive seismic instruments bearing his name, the principal ones being: 1) the Omori-Alfani tropometrographs; 2) an orthoseismograph; 3) two aperiodic pendulums; 4) a bipendulum; 5) the Galitzin-type photoseismograph; 6) the accelerometric vibrograph; 7) the portable trepidometer.
He studied with particular care and insight the vibrations and deflections of various national monuments, such as the bell tower of Pisa, the tower of the Palazzo Vecchio in Florence, and Brunelleschi’s dome. In the latter, he repeated the pendulum experiment first carried out in Italy by the members of the Accademia del Cimento, and later in Paris by Foucault in 1851. He was the first to establish in Italy a radiotelegraphic station for the time service of seismic instruments; Marconi tested its operation.
An indefatigable scholar, having determined the epicentres of various earthquakes, he gave the authorities timely warning so that aid could be sent to the devastated centres (Messina: 28 December 1908; Avezzano: 13 July 1915; Mugello: 29 June 1919; Apuan Alps: 7 September 1920), and he always went to the affected sites to study the phenomenon directly.
Through writings and lectures he disseminated science with clarity and simplicity. He leaves approximately a hundred scientific papers on physical, technical, and structural seismology; on astronomy and meteorology, in which field he became known for the invention of an altimeter and a microbarograph, admirable for their precision. He also invented an automatic telephone and a tachometer. He contributed greatly to the study of Florence’s climate. He was a lecturer in seismology at the University of that city.
A. was not only a highly esteemed scientist, but also a priest who deeply felt the dignity of his ministry and devoted himself generously to comforting and bringing back to God lost souls: the case of Giosuè Borsi, whom he brought back to the Christian faith, became known everywhere. He was father and brother to those who entrusted their consciences to him, in order to have their anxieties and wounds healed.
His death constituted a grievous loss for the entire city. On his tomb, at Rifredi, a parchment bears the words: « Doctrina usus est ut hominum animos ad Dei cultum converteret ».