The Popes and Science / The History of the Papal Relations to Science During the Middle Ages and Down to Our Own Time

by James J. Walsh

During the second period of the history of the Vatican Observatory at the end of the eighteenth and the beginning of the nineteenth century, the upper story of the Gregorian tower was fitted up with meteorological and magnetic instruments with a seismograph, a Dolland telescope, a small transit instrument and a pendulum clock and a series of very careful observations on a number of subjects made. From 1800 to 1821 Gilii made an uninterrupted series of meteorological observations, reading the instruments twice a day, at 6 a.m. and 2 p.m. The observations are published for seven years and the rest are preserved as manuscripts in the Vatican Library. There are also deposited astronomical observations of eclipses, comets, Jupiter's satellites and of a transit of Mercury. Gilii laid down the meridian line in front of St. Peter's with the obelisk as a gnomon and the readings of the seasons by the length of the shadow. To him are due also the bronze marks on the floor of St. Peters, giving the comparative lengths of the greatest churches of the world. It was he who placed the first lightning rod on the cupola of St. Peter's. The [{479}] heavens, the weather, the lightning are supposed often to be set by religiously inclined persons particularly under the care of Providence, to be influenced by prayer, yet these are exactly the three departments of science that were faithfully followed in their detailed scientific aspects during all the centuries by the Papal Astronomers under the patronage and with the approval of the Popes, with the avowed purpose of discovering the natural laws under which they occur.

Two of the distinguished teachers of mathematics and astronomy of the end of the eighteenth century at Rome were Father Thomas Leseur, professor at the Sapienza, and Professor Franz Jacquier, professor at the Roman College, who wrote a commentary on Isaac Newton's Principia which did much to popularize Newton's work.

When, because political influence was brought to bear very strongly on the Pope, the Jesuits were suppressed in 1773, the Roman College passed from their hands and the real reason for allowing the Vatican Observatory on the Papal grounds to fall into disuse was manifest, for the Popes at once took up the question of re-establishing their own observatory. Not long after the suppression we find Monsignor Filippo Luigi Gilii placed in charge of the reorganized Roman Observatory by Cardinal Zelada, who had been appointed Vatican Librarian in 1780, and who found the old Gregorian tower available as a centre of astronomical observation and investigation of which Rome had been deprived since the suppression of the Roman College. After the restoration of the Jesuits early in the nineteenth century, the Roman College was opened once more and distinguished Jesuits, some of them with world-wide reputations, did their work there. With the occupation of Rome by the Italian government in 1870 the Jesuits were banished, the Roman College with its observatory was once more deprived of the learned expert direction of the Fathers of the Order, and once more efforts were made for the re-establishment of a Vatican observatory which is now in existence and under the direction of a Jesuit.

Another of the distinguished scientists of the eighteenth century who taught for a time at Rome was Father Beccaria, whose name is well known in the history of electricity. When not yet forty years of age he was elected a fellow of the Royal Society of London, always a much envied distinction, and as a consequence of his election some of his important papers relating to electricity and various astronomical subjects were sent to the Royal Society [{480}] and published by them. While no great discovery in physical science is attached to his name, few men did as much as he to awaken enthusiasm and experimental investigation into science in his time. He was one of the pioneers of the great scientific movement of the nineteenth century. Priestley called him one of the most eminent of all the workers in electricity on the Continent, and Professor Chrystal, in his article on electricity, in the Encyclopedia Britannica (ninth edition), gives him an important place. He had been trained to be a professor of experimental physics for his Order, and at this time every one of the teaching orders with colleges at Rome had distinguished men among their faculties.

The well-known astronomer, Father Piazzi, whose discovery of Ceres, the first of the planetoids found in the space between Mars and Jupiter, caused great excitement among astronomers, and whose subsequent work in astronomy brought him membership in many of the scientific academies of Europe, had been for some time a student and a teacher in Rome. While there he was a colleague of Professor Chiaramonti, who later became Pope Pius VII. During all his subsequent brilliant scientific career his special friendship with the Pope continued, and with all his many memberships in scientific bodies he remained a member also of the Theatine religious order which he had entered at a very early age.

After the restoration of the Jesuits the work in the sciences reverted once more to the Jesuits at the Roman College and the Vatican Observatory was discontinued. The interest of the Popes in science, however, was very well illustrated by the apostolic letter of Leo XII, Quod divina sapientia, which gave instructions to all Catholic educational institutions, as to observatories, publications and intercourse with foreign scientists.

The Jesuits at the Roman College reached noteworthy distinction for their astronomical work during the nineteenth century. Father Secchi came to be looked upon as probably one of the most distinguished astronomers in Europe. He received many prizes for his observations, for his invention of instruments and for important discoveries. His work on the sun, published in his book, Le Soleil, represents some of the most important contributions ever made to this department. It was translated into most modern languages. His observations on the corona of the sun during eclipses and especially photographs of the corona, place him among the great original contributors to modern astronomical knowledge. He made a critical examination and classification of the spectra of four thousand stars entailing an enormous amount of [{481}] work. He believed firmly that it was no use making observations unless they were thoroughly recorded and made available for others. His literary work in astronomy is almost incredible. He sent nearly 700 communications to 42 scientific journals, over 300 of which appeared in the Comptes Rendues and in the Astronomische Nachrichten, the French and German journals of astronomy that are the authoritative records of contemporary scientific work. In this country Newcomb and Langley quote from Secchi frequently and use his illustrations. He was the founder of a new branch of astronomy, Stellar Spectroscopy, and Secchi's types of solar spectra will probably ever remain an essential illustration in astronomical text-books.

Another of the astronomers who did excellent work among the Jesuits at the Roman College during the nineteenth century was Father De Vico, whose determination of the rotation period of Venus and the inclination of its axis was considered so exhaustive that it was not questioned for half a century. He also measured the eccentric position of Saturn in his rings and observed the motions of the two inner moons of this planet which had not been seen before this time except by Herschel. Father De Vico also discovered eight comets, one of them being the well-known comet with a period of rotation of five and a half years which bears his name. Father De Vico and Father Secchi were driven from Rome by the Revolution of 1848, but were brought back to continue their work just as soon as it was possible. In the meantime they continued to be personal friends of successive Popes, encouraged in every way, aided in their work and looked upon as ornaments of the Church. They were thoroughly respected by their Order and there was never the slightest question of any possibility of all their studies in science and all their profound investigation of the deepest scientific subjects disturbing their faith in any way.

One of the well-known contributors to astronomy during the nineteenth century was Father Benedict Sestini, who for his mathematical ability was appointed assistant to Father De Vico of the Roman Observatory. He was banished from Rome with his brother Jesuits by the Revolution of 1848, and taught at Georgetown College, Washington, D. C, for many years. His principal work is his catalogue of star colors, published in the Memoirs of the Roman College, 1845-47. He had very keen vision and fine skill with the brush, so that his catalogue, which embodies the entire B.A.C. Star Catalogue, from the North Pole to thirty degrees south of the equator, will be invaluable for deciding the question [{482}] whether there are stars variable in color. He made a series of sunspot drawings which were engraved and published as appendix A of the United States Naval Observatory volume for 1847, printed in 1853. He was the teacher of mathematics and astronomy to the American Jesuit students and wrote a series of text-books for that purpose.

As we have said, the Italian government suppressed the Roman College, declaring it State property and this prevented further work in the observatory there, which had been for nearly half a century under Father Secchi and Father De Vico, one of the most important centres in the world of astronomical advance. Beggared by the Roman confiscations which compelled the Popes to cut off all their support of scientific and educational work except what related closely to clerical education, it was not until 1888 that Pope Leo XIII found himself in a position to re-establish a Roman observatory in connection with the Vatican. In 1888 the Italian clergy, for the celebration of the Golden Jubilee of Pope Leo XIII, presented to him, knowing from his interest in science how agreeable such a gift would be to him, a collection of astronomical instruments and the Gregorian tower was selected once more for its former purposes and the Barnabite, Father Denza, the well-known founder of the Italian Meteorological Society, became the official head. Pope Leo XIII ceded to the Vatican Observatory a second tower more than 400 metres distant from the Gregorian. As this was of immense strength, the lower walls being some five yards in thickness, it seemed strong and firm enough to support the thirteen-inch photographic refractor which was ordered from Gauthier. Seven volumes of observations were published during the next fifteen years, four under Father Denza, a fifth under Father Lais and the last two under Father Rodriguez, an Augustinian, who was a specialist in meteorology.