The Bolognese Specola

12 - The Accademia dell’Istituto delle Scienze and the building of the new Observatory.

Manfredi’s observations to discover a yearly motion of the "fixed" stars, that would provide experimental proof for the rotation of the Earth around the Sun and verification of the Copernican system, were suddenly interrupted, as we have seen, by the dispute between Count Luigi Ferdinando Marsili and his family over the donation to the city of Bologna of his scientific collections and the part of the home housing them.

The Bolognese Senate managed to dissuade Marsili from taking the instruments and collections away from Bologna, on the understanding that

"a place would be found them that was big enough and suitable enough to house them; a chemical laboratory would be set up; there would be enough rooms for a sizeable library; an observatory tower would be put up; stipends put aside for the professors; funds provided for the purchase of books, and machines for physics experiments". (83)

The agreement being subject to the consent of the Holy See and a financial commitment on its part, Marsili took himself to Rome to set in motion "all the most efficacious this end" (84). It was on this occasion he got the painter Donato Creti (1671-1749) to portray the main instruments of the Marsili Specola in a series of eight pictures that depicted astronomers intently observing the planets, which he presented as a gift to Pope Clement XI (1649-1721). The pictures are still preserved in the Pinacoteca Vaticana, while some preparatory sketches can be found at the Bologna Pinacoteca and at the Art Institute of Chicago (85).

The Pope contributed 2400 scudi to the operation and finally, on January 11, 1712, the notarial act was drawn up for the donation that would launch the Istituto delle Scienze di Bologna. The place chosen to house it was the family mansion of the Poggi family which was then far enough out of the centre to make its price reasonable and far enough away from the hills to get a good view of the sky for astronomic observations.

Further contributions to the Institute, solicited again by Marsili, came from the ecclesiastic authorities in the form of money and equipment, including a clock donated by cardinal Giovanni Antonio Davia (1660-1740) and a telescope of Giuseppe Campani - celebrated lens-maker from Spoleto - with a 22 foot (over 8 m) focal length [file 29], given by cardinal Sebastiano Antonio Tanari (86). The octagonal cypress tube and the telescope lens are today on display in the Turret Room of this museum.

The Academy and the Institute of Science were inaugurated on 13 March 1714 and soon became famous throughout Europe. In his eulogy to Marsili read at the Paris Académie des Sciences in 1730, Fontenelle compared the Bolognese institution to Bacon’s New Atlantis, saying:

"Six professors live in this building, each in his own apartment. It’s like seeing the Atlantis of Chancellor Bacon, the dream of a sage realized." (87)

While on one side Marsili continued to feel a kind of municipal patriotism for his city, from whose aristocracy he came, his cosmopolitan background did lead him to recognize the Académie and the Royal Society as inspirational models for the renaissance of experimental studies in Bologna. The Istituto and the Accademia delle Scienze in Bologna were one of the more faithful attempts to reproduce the French model in a different context, thanks too to the close ties with Cassini and his personal relations with Marsili, even if the English experience was not completely ignored. Marsili was aware of the fact that his idea of scientific research could only be achieved with state support, but the cultural and social conditions in the city and in Italy generally placed limits on such plans. At the beginning, for example, because of both the nature of the models and the organization, many Baconian characteristics came to the fore, as was pointed out by Fontenelle. The Istituto delle Scienze was a public institution and a close tie was contemplated between the work of the academicians and the technical needs of the craftsmen; subsequently, however, the link-up with the productive sectors of society - where as it happened the entrepreneurial classes were of no importance - was lost or else not realized.

The plan for geographical reconnaissance, one of the arguments used to obtain papal approval, was never carried through and does not seem to have been solicited at all by the central government which however made frequent use of the University’s best mathematicians for the solution of the most pressing problems regarding drainage.

Marsili’s initial intentions were probably of a purely personal nature: to put together a private collection so he could devote himself to studying once he had given up his military career. The leap in quality from this to the Institute was, for the period, unique in Italy. Many courts had collections of scientific instruments, usually little used, while individual scholars no longer had the means to undertake research.

If Bolognese science managed to keep up with European standards in the first half of the XVIIIth century, this was not due simply to developments within individual disciplines (such as the rapid assimilation of Cartesian geometry, infinitesimal analysis and, later, Newtonian optics and mechanics), but also to its high level of institutionalization.

The working programme of the Institute - and hence of the Specola - banned all theoretical research for obvious reasons of coexistence with the University, but, since those attending the one also attended the other, the division was not always that clear. Much more drastic was the ban on all metaphysical subjects, probably due in some part to the influence Geminiano Montanari had on his pupils. Limiting science to a carefully prescribed field did however avoid any dangerous clash with theology and in many ways made it actually supportive of Church doctrine.

Thus the Specola continued to work with positional astronomy, neglecting the development of the new celestial mechanics. The most important contributions on the subject were published, in the second half of the century, in the Academy’s journal (the Commentarii) by non-Bolognese authors, in particular Paolo Frisi (1782-1784) from Milan, who was of the opinion that the most outstanding contributions to astronomical studies would come from theory and not observations. Frisi was not the only author of note to publish articles on astronomy in Bologna: mention should be made at least of the Jesuit from Ragusa, director of the Brera Observatory, Giuseppe Ruggero Boscovich (1711-1787), witness to the cultural flowering and prestige of the institution, even in a period of steady decline for the Specola. Frisi was also honorary lecturer in Mathematics at the University (from 1764 to 1784) - though he never taught there - as too was Maria Gaetana Agnesi (1718-1799) who had the same title from 1750 to 1795 for the chair of Analytical Geometry.

The building that housed the Istituto and the Accdemia delle Scienze, as had been guaranteed Marsili by the Bolognese Senate, was to have a tower built onto it to lodge the "Specola". During its construction the astronomical instruments brought from the Marsili observatory were put in a room, thought to be one of the rooms situated on the first floor to the entrance staircase of the tower - the door of which is walled up today as it was then - and on which Manfredi suggested engraving the legend:

"These instruments, which will soon be moved to a higher position, will allow your mind to understand how the course of the stars unfolds".

This inscription was almost certainly never put up - like the others ordered by the Assunteria (Institute administration) for each room of the Institute - since no trace has been found of it (88).

The building of the Specola was a fundamental part of Marsili’s cultural project. Of all the Marsili collections, that various naturalists had also been involved in, it was only the astronomic instrumentation which at first could be used as something other than just a personal instrument of research. This had been made possible not simply by the role of Manfredi and Stancari in the Accademia degli Inquieti but also by a specific project of the general. He had in fact accumulated instruments and books in his Bolognese house with the intention of seeing them used by an academy that would be devoted exclusively to astronomy and experimental physics. The actual reasons that lay behind this grand project of Marsili are not easy to analyse. Undoubtedly on the one hand there was his scientific training in the "Bolognese branch of the Accademia del Cimento", on the other his travels throughout Europe and in particular to those countries where the interest of the bourgeoisie in the systematic study of nature had given rise to the great Academies. Subsequent developments showed the limits on reproposing this model in a different economic, social and indeed academic climate; in particular, Marsili’s expectations about the Institute’s ability to make itself an agent of renewal in the minds of the Bolognese political class and to provide new technologies for its economy were doomed to failure.

Similar motivations, however, if they can easily be attributed to the study of experimental physics, should be more attenuated as regards astronomy. In Marsili’s plans for the new Specola there was undoubtedly great interest in the astronomical determination of the geographical position of Italy’s main cities and thence the revision of maps that till then had been merely approximative. What it in fact amounted to was a redrawing of the old Italian maps - which were still those in Giovanni Antonio Magini’s work, published posthumously in 1620, Atlante Geografico di 61 Carte called Italia - through actual reform of astronomy, as "the French had done for France" and which, according to Manfredi, "was the main fruit borne by astronomical observations" (89).

Once the building had been found to house the Marsili collections, Giuseppe Antonio Torri (1655-1713), Regiment architect since 1696 and already charged on a previous occasion by Marsili to find the suitable building, was commisioned, in 1712, to actually build the Specola (90).

There were at that time no practical references on how to construct a building of this kind, if we exclude the spacious Paris Observatory: observations were almost always carried out in the country, outside the city, in carefully selected areas, like Uranjeborg designed by Tycho Brahe, or on small hills, like the Greenwich Observatory. In consequence the architect Torri, who had been involved in the building of the Marsili Specola, discussed at length every detail of the job with Manfredi who already ten years before had outlined, in his correspondence with Marsili, plans for an imaginary building designed to house special and at times encumbering equipment (91).

The architect’s plans were sent to Clement XI for approval and work was then able to start. Unfortunately, the death of Torri in 1713 and the difficulties the Assunteria of the Institute found itself in for the rise in building costs brought work to a halt where it remained until 1722-23.

Manfredi wrote in the Volume primo del registro delle osservazioni da farsi nell’Osservatorio astronomico dell’Istituto delle Scienze (First Volume of the observation logbook to be done in the Astronomical Observatory of the Institute of Science - records begin on 5 November 1723 and run to 30 December 1844):

"The building of the observatory of the Institute of Science began at the said Institute in the year 1712, but having been interrupted for many years, when it was of no use for celestial observations at all, the Professor, when the occasion presented itself, was advised to find first one place and then another in the Institute building, and sometimes even outside it, to explore the part of the sky he was interested in, and thus, outside a few eclipses, he managed to observe little or nothing in that period".(92)

In 1720 Count Marsili obtained another 15000 scudi from the Pope to complete the Institute. The money was used to enlarge the natural history collections, complete the physics laboratory and carry on with the building of the Observatory.

Torri’s plans have never been found but an idea of his project for the Specola can be gleaned both from a medal struck in Rome by Ermenegildo Hamerani in 1720 to commemorate the founding of the Institute of Science, and from the models commissioned from the architect Giovan Battista Piacentini on the drawings of Torri for the occasion of the reopening of the building site in 1722. (93)

Finally, Carlo Francesco Dotti (1678-1759), architect and master builder of the Institute, was given the job of finishing the work. Manfredi noted in his registers:

"In 1722 building was restarted, including the completion of the three apartments of the Tower which rose to the level of the first terrace, on which the Turret was to lie; the latter was built in the following year 1723, lacking however paving on the floor and a parapet for its terrace and the other one above".

From October to December 1724 the tower was used to make some observations and we find in Manfredi’s notes that

"The observations are again interrupted because of the difficulty of going on with them; the Astronomer has not yet been assigned his living quarters, and...various other comforts are missing, the doors and windows of the Turret not having been fitted yet".

The order was therefore given by the Pope, Innocent XIII , that the building of the Observatory should be finished by 1725 so that it could be visited by the foreigners who would come to Rome for the Holy Year (94). Manfredi then succeeded in opposing the proposal of some administrators that the tower be higher than the church of San Pietro in Bologna, something which would have slowed down work all over again. The building was completed inside a few years, with several alterations to the original plan - raising of a floor, reduction in width of the balconies, etc. - and in 1727 the major instruments of the Marsili Observatory could be installed.

Manfredi had noted at the beginning of the previous year:

"On 29 April 1726 the astronomer was at last able to come and live in the Institute..."

and at the end of the year:

"In this month of December in the year 1726 everything to do with the building of the observatory was completed. The iron gate at the entrance to the hall or chamber of the Turret was fitted. The iron attachments with screw-holes for mounting stands and managing the long telescopes that, along with other instruments, had begun to arrive and be used in the said Chamber were built into the two parapets, upper and lower, of the observatory. The cover of the aperture was also completed, positioned along the meridian in the room that was to lodge the mural semicircle, which was hung from its iron attachments, and the hooks with handles for opening and locking the said cover were made. Likewise a shutter with its fitting for maneuvering it was made and fitted, with the aim of covering and uncovering the hole that lets in the Sun on the meridian in the said Room of the Semicircle, and two notches were made in the two iron fixtures placed at the two ends of the said meridian through which the string marking the arrival and exit of the sunlight is stretched in the plane of the meridian." (95)

The turned "columns", two of which were 11-foot high (4.2 m), the other two 8-foot (3 m), were used together and were fitted with the mechanisms necessary for raising and lowering the telescopes. They were painted green with white veining to look like marble. They belonged to the Marsili Observatory and are described fairly extensively in the 1712 inventory. (They still existed in 1843 and were sold at the end of the last century together with other furnishings that had become useless and cumbersome, including a wooden model of the meridian room).

It took several more months, however, to install and set up all the equipment which comprised the instruments from the Marsili Observatory along with the telescope donated by cardinal Tanari, which was mentioned above [file 29], and a clock, quadrant, 13-foot telescope [file 25] and reflecting telescope, along the lines of Newton’s, all donated in 1725 by cardinal Davia (96). The history of these instruments can be traced back through the observation records and the numerous inventories held in the Archives of the Department of Astronomy. The inventories show us that some instruments had been transported to the Institute that even then were considered relics of the past. The 1712 inventory refers to, the "sextans ligneus, quo Excellentissimus Comes Marsilius utebatur cum primum Astronomicis se studiis exerceret" and the "instrumentum azimuthale ad altitudines, simulque verticales Stellarum circulos observandos, Norimbergae Anno MDCXCVI fabricatum...Eo instrumento Marsilius cum de Caelo observationes in castris istitueret, utebatur".

The astronomer was entrusted with not only the Observatory but the Military Room too and was, in particular, given charge of the lectures on Ballistics. We do in fact read in the records of the donation:

"Control over the Observatory, and of the Military Room, should be given to the astronomer, who will carry out continuous Celestial observations, according to the defined year, which will be established in the Academy of Science, and who several days a week will also teach "fortifications" and "artillery" with the help of the exquisite books, that are in the library, and the many models, and cannons existing in his Room..." (97)

The use of the different rooms in the mid-1700s is gleaned from the 1746 inventory.(98)

At first astronomy only occupied the four floors of the tower. It was on the first of these, where the room that provided access to the Meridian Room and the adjoining chamber was - today partially occupied by the shaft of the multi-mirror telescope, built in this century by Horn-d’Arturo - that the working rooms of the astronomer and his assistant were supposed to be. By 1746 the old instruments of the Marsili Observatory, which had fallen into disuse with the arrival of the English instruments we shall say more about later, were already kept in the middle room on that floor. There were also various terrestrial and celestial globes and the armillary spheres, representing the planetary system (today exhibited in the "Globe Room" of this museum [files 51-62]). The floor directly above was meant as the living quarters of the astronomer. On the third floor (the present-day "Globe Room") there were other instruments, notably a brass parallactic telescope, donated by Benedict XIV (1675-1758) in 1752, the reflecting telescope donated by Cardinal Davia and two quadrants, one already in the Marsili Observatory and one donated by Cardinal Albani in 1728. The quadrant is named for the first time in the observation records under the date December 31, 1843, but was not refound. The same with the parallactic donated by Benedict XIV.(99)

In the great inner hall of the turret (in the museum called today the "Turret Room") were kept the quadrant donated by Davia and all the accessories for the long telescopes (which are still today exhibited there [files 24-31]), the lenses of the two telescopes by Campani, in their turned wood frames, those of Marco Antonio Cellio (second half XVIIth century) and Chiarelli, both 14 foot (5.4 m), those of the two 8 foot (3 m) "germanic" telescopes, the tin tubes these lenses were used on, the wooden stands to support them on the object lens side, the tripods for support on the eyepiece side, and finally the cycloidal clock of Isaac Thuret (?-1706), which has since been lost (100).

Later, as is shown by the 1843 inventory, the astronomer must have been living on the second floor of the building, where the optics and lathe rooms had been. The middle room of the floor above, the first floor of the tower, held the lecture hall that was fitted out with a big table surrounded by nine benches and an armchair, placed on a wooden support, for the teacher. On the floor above were the working and study rooms. The "nautical things" had been moved to the third floor of the tower, including the model ships that can today be found in the Ship Museum of this University.

  1. - G. Fantuzzi: op. cit. p. 229.
  2. - G. Fantuzzi: op. cit., p. 230.
  3. - G. Fantuzzi: op. cit., p. 231 e lettera XXIX. Detti quadri si conservano ancora nella Pinacoteca Vaticana, mentre alcuni bozzetti preparatori si trovano presso la Pinacoteca di Bologna e presso l'Art Institute di Chicago.
    G. Horn-d'Arturo: 1957, Coelum, XXV, p.1.
    G. Ruggieri: 1957, Coelum, XXV, p.3.
    S.A. Bedini: 1980, in Proceedings of the Eleventh Lunar and Planetary Science Conference, p. XIII.
  4. - G. Fantuzzi: op. cit., p. 238.
  5. - B. Le Bovier de Fontenelle: 1730, Eloge de M. le Compte Marsigli, Hist.Ac.Roy.Sciences (ed. di Amsterdam), p.191.
    "In questo palazzo abitano sei professori, ognuno nei propri appartamenti. Sembra di vedere l'Atlantide del Cancelliere Bacone, il sogno di un sapiente realizzato."
  6. - E. Baiada, F. Di Palma: 1989, Saecularia IX, 9, p. 20.
    "Questi strumenti, che presto saranno trasportati in un posto più elevato, permetteranno alla tua mente di comprendere come si svolge il corso degli astri."
  7. - G. Fantuzzi: op. cit., p. 319 (lettera XXIX di Eustachio Manfredi a Marsili in Roma del 30 agosto 1711).
  8. - F. Ceccarelli e P.L. Cervellati: 1987, Da un Palazzo a una città, il Mulino, Bologna.
  9. - Lettere inviate da Manfredi a Marsili il 24 e il 31 gennaio 1702, Biblioteca Universitaria, Bologna, Mss. Mars. 80a.
  10. - I registri, conservati nell'Archivio del Dipartimento di Astronomia, iniziano con il 5 novembre 1723 e terminano il 30 dicembre 1844.
  11. - D. Lenzi: 1988, Le trasformazioni settecentesche: l'Istituto delle Scienze e delle Arti, in Palazzo Poggi: da dimora aristocratica a sede dell'Università di Bologna, A. Ottani Cavina (a cura di), Nuova Alfa Editoriale, Bologna, p. 64.
  12. - G. Fantuzzi: op. cit., p. 253
  13. - Le "antenne o colonnette", lavorate al tornio, due alte 11 piedi (4,2 m), altre due 8 piedi (3 m), da usarsi accoppiate e fornite dei meccanismi necessari per alzare e abbassare i cannocchiali erano dipinte di verde con venature bianche simulanti il marmo. Esse erano appartenute all'Osservatorio Marsiliano e sono descritte abbastanza estesamente nell'inventario del 1712. Esistevano ancora nel 1843 e furono vendute alla fine del secolo scorso, assieme ad altre suppellettili divenute inutili ed ingombranti, tra le quali vi era un modello in legno della camera meridiana.
  14. - Notizie dell'origine e progressi dell'Istituto delle Scienze di Bologna...: 1780, Bologna, p. 185.
    Secondo G. Fantuzzi - op. cit. p.238 - l'orologio era stato donato nel 1713.
  15. - Arch. Stato Bologna, Fondo Assunteria d'Istituto, Div. 7.
  16. - L'utilizzo dei vari ambienti a metà del Settecento si ricava dall'inventario del 1746.
  17. - Il quadrante è nominato per la prima volta nei registri di osservazione sotto la data del 31 dicembre 1843, ma non si è ritrovato. Così anche la parallattica donata da Benedetto XIV.
  18. - Per le notizie relative a questo orologio si veda E. Baiada, A. Braccesi: 1983, Lo sviluppo della strumentazione astronomica dell'Osservatorio Marsiliano e della Specola dell'Istituto delle Scienze di Bologna dal 1702 al 1815, in Gli strumenti nella storia e nella filosofia della scienza, a cura di G. Tarozzi, Istit. per i beni artist. e cult. della Regione Emilia-Romagna, p. 83.