The Borghesi Astronomical Clock in the Museum of History and Technology Part 1

The Borghesi Astronomical Clock in the Museum of History and Technology.

by Silvio A. Bedini.

_The Borghesi Astronomical Clock_

_In the Museum of History and Technology_

_The history of the 18th-century Borghesi astronomical clock is described here from contemporary source material. The evolution of its design by Father Frances...o...b..rghesi and the building of the complex mechanism devised by the clockmaker, Bartolomeo Antonio Bertolla, is a story of the vision of one man turned into reality by another. The result of their collaboration is the unique, astronomical timepiece now in the Museum of History and Technology._

THE AUTHOR: _Silvio A. Bedini is curator of mechanical and civil engineering in the Smithsonian Inst.i.tution's Museum of History and Technology._

"... All this work I had performed eagerly, so that, while in my room, I might contemplate leisurely, both during the day and in the night, the true face of the heavens and of the seas un.o.bscured by clouds, even though I had no astronomical equipment."[1]

With these words, Father Frances...o...b..rghesi (1723-1802) of Mechel described the reasons which inspired him to invent a unique astronomical clock which is now in the horological collection of the Museum of History and Technology.

This complicated mechanism, which performs a mult.i.tude of functions, was designed by Father Frances...o...b..rghesi, a secular priest in Venezia Tridentina. It was constructed in 1764 under his direction by a provincial clockmaker named Bartolomeo Antonio Bertolla (1702-1789) of Mocenigo di Rumo. It was the second of two complicated astronomical clocks which Father Borghesi designed and which Bertolla constructed.

According to contemporary sources, this clock was presented to the Empress Maria Theresa of Austria soon after its completion.

Its history is rather hazy, except for the fact that in 1780 this second Borghesi timepiece was still in the Imperial Palace in Vienna. The clock was again noted in 1927 when it was sold at a public auction in New York.[2] Subsequently, it was acquired for the Smithsonian Inst.i.tution.

Development of Astronomical Clocks

The history of the great theoretical and mechanical achievement which the Borghesi clock represents has been most adequately covered elsewhere.[3] Consideration of the development of equation and astronomical clocks is required here only for the purpose of relating the Borghesi timepiece with the other significant developments in this branch of horology.

The invention of the anchor escapement in about 1670, and the consequent greater accuracy in time-telling, led to increased preoccupation with precision. Daily differences in time as recorded by sundials and clocks became more noticeable. Finally, in the second half of the 17th century, some attempt was made to construct mechanical clocks combined with sundials as well as astronomical clocks.

With the improvement of precision time-telling, it became necessary to reconcile the actual difference between true and mean time. Although a great variety of time-equation tables were produced, there was a considerable margin for error in their use. This led to the construction of mechanical clocks in which the equation of time was automatically accomplished. A few were produced late in the 17th and early 18th century at considerable cost and, consequently, with little popularity.

Equation sundials were also developed which were elaborately ingenious, but they were not completely practical. Inevitably, they were supplanted by the mechanical equation clock.

Probably the first doc.u.mented mention of an equation clock is in the diary of John Evelyn who recorded that in 1666 he visited the Royal Society where he witnessed a curious clock, which showed the equation of time, being presented by a certain Mercator. More data on the subject appeared in the first two decades of the 18th century, when Henry Sully, Joseph Williamson, Daniel Quare, and Thomas Tompion--who were among the foremost English clockmakers of all time--produced elaborate examples of these timepieces. Another significant maker was Dowe Williamson, who became Court Clockmaker to Emperor Charles VI of Austria. In London, Joseph Williamson produced some of the finest astronomical timepieces of this type that have been known. The interest in the subject next s.h.i.+fted to France where many fine examples were produced during the first half of the 18th century.

Just after the middle of the 18th century, the subject of astronomical clocks suddenly became a major horological preoccupation in another region, namely, Austria, where the work in this field was apparently done exclusively by members of the clergy. The earliest was Father Philipp Matthaus Hahn (1739-1790) of Wurttemberg.[4] Father Hahn considered the equation of time as only one part of a plan to represent astronomical occurrences by means of clockwork. In addition to planetaria and similar mechanisms, Father Hahn produced two extraordinary astronomical, tall-case clocks, both of which survive in public museums.

ACKNOWLEDGMENTS

The author wishes to acknowledge the valuable a.s.sistance received from the following: DR. AMOS AVERY, Amherst, Ma.s.sachusetts; MR. EDWIN A.

BATTISON, curator of light machinery and horology, U.S. National Museum; DOTT. RICHARD BLAAS, Oesterreiches Staatsarchiv, Vienna; DOTT. ADOLFO CETTO, librarian, Biblioteca Comunale di Trento, who made copies of Borghesi's two volumes available; SIGNOR MARIO DI MARIO, editor of _La Clessidra_, Rome, who permitted several of the ill.u.s.trations in Sig.

Luigi Pippa's article to be used herein; MR. WALTER A. GILBERT, Norwich, Connecticut; DR. HEINRICH LINARDI, Uhrenmuseum der Stadt Wien, Vienna; SIGNOR LUIGI PIPPA, Milan, Italy; CAV. ING. GUIDO UCELLI DI NEMI, Presidente, and DOTT. FEDERICO MORELLI and CAV. ORAZIO CURTI of the Museo n.a.z.ionale della Scienza e della Tecnica, Milan, for their cooperation on the descriptions and ill.u.s.trations of the restored clockshop of Bartolomeo Antonio Bertolla; and DR. EDWARD WATERS, Division of Music, Library of Congress, Was.h.i.+ngton, D.C.

The translation from Frances...o...b..rghesi's Latin texts, which made this study possible, were made by: REV. NEIL HERLIHY, S.J., REV. FRANCIS J.

HEYDEN, S.J., and REV. STEPHEN X. WINTERS, S.J., Georgetown University, Was.h.i.+ngton, D.C.; and REV. DANIEL HUNTER, O.P., and REV. ROBERT STENGER, O.P., Dominican House of Studies, Was.h.i.+ngton, D.C.

[Ill.u.s.tration: Figure 2.--PORTRAIT OF FATHER FRANCEs...o...b..RGHESI, inventor and designer of the astronomical clock in the Museum of History and Technology.]

Another of the clerical clockmakers was Father Aurelia.n.u.s a San Daniele (1728-1782), an Augustine monk in the monastery of the Imperial Court at Vienna.[5] His four complicated astronomical clocks, which exist in museums at present, are comparable to those produced by Father Hahn. The third cleric was Brother David a San Cajetano (1736-1796) in the same Augustine order to which Father Aurelia.n.u.s belonged. He achieved note as the author of various publications, including _Neue Radergebaude_[6]

[New Construction of Wheels] relating to planet-wheels, or gear-trains containing epicyclic elements. He constructed a clock based on an elaborate astronomical design which was substantially different from the others. The fourth of the ecclesiasts who designed astronomical clocks in this period was Father Klein of Prague, who produced a complicated astronomical timepiece in about 1738.

The fact that such important and outstanding examples of astronomical clocks were produced exclusively by ecclesiasts in Austria during the second half of the 18th century is especially significant. It is particularly so when a fifth cleric is added to the group, also an Austrian subject although Italian by heritage, in the person of Father Frances...o...b..rghesi.

Although only Father Borghesi's second astronomical clock is now known, it is apparent that this example in the Museum of History and Technology represents an experiment in astronomical time-telling comparable to any of the timepieces produced by Father Hahn, Father Aurelia.n.u.s, Brother David a San Cajetano or Father Klein.

This combination of five clerical clockmakers who lived in the same region during the same period of time is sufficiently unusual. However, the fact that each of them apparently worked without a.s.sociation with any of the others leads to the conjecture that a common factor must have led them to their individual preoccupation with astronomical horology.

What the link may have been is not apparent from the surviving records of the lives and works of these clerics. Certainly it was not an interest in astronomy or clockmaking per se, because other than the astronomical clocks, none of these horological inventors--with the possible exception of Father Hahn--worked in any other aspect of the fields of astronomy or horology. However, after a comprehensive study of Father Borghesi's writings, there is little doubt of the religious basis of his own inspiration.

Designer Borghesi

Father Borghesi's story takes place in the picturesque mountainous region of what was then known as Venezia Tridentina (since 1947, Trentino-Alto Adige) in northern Italy, along the Tyrolean border of Austria. Because of its strategic position as the pa.s.sage between Innsbruck and Verona, the possession of the Tridentina was contested again and again in the European wars, but during Father Borghesi's lifetime, the Tridentina was under Austrian domination.

[Ill.u.s.tration: Figure 3.--PANORAMA of the village of Mechel in the valley of the Non, birthplace of Father Borghesi.]

Deep within this mountainous district is the romantic valley of the Non, or Anauni, with its great forests and ancient castles. Most maps do not mark it, and the tourist guides ignore it.[7] One of the chief communities is Cles, with its historic Renaissance buildings. The major city of the region is Trent on the Adige River, with its surviving Roman relics and Romanesque and Renaissance architecture.

The little villages scattered throughout the valley of the Non played no part in history, but such names as Mechel and Mocenigo di Rumo reflect the interchange of sovereignty. It was in the little village of Mechel that Frances...o...b..rghesi was born in 1723.[8] Local records are meager and inadequate, and many of the details of Borghesi's life must be a.s.sumed. Inasmuch as the village was in a rural, agricultural district, Borghesi may have come from a family of farmers, vintners, or village tradesmen. Borghesi sought an education by entering the priesthood and was ordained a secular priest in Salzburg. He was first a.s.signed as curate to the village parish of Rumo in the valley of the Non, a short distance from his birthplace.[9] Later, he was transferred to his native Mechel. He was inherently a man of simple tastes and of great piety. He tended to the needs of his mountain villagers and attended the births, weddings and deaths of his paris.h.i.+oners. It was during his a.s.signment in this tiny community that Father Borghesi met and became friendly with the clockmaker, Bartolomeo Antonio Bertolla of nearby Mocenigo di Rumo.

Clockmaker Bertolla

Bartolomeo Antonio Bertolla was born in Mocenigo di Rumo, a short distance from Mechel, in 1702.[10] Nothing is known of his boyhood, other than the fact that he was mechanically inclined. At the age of 17 he was apprenticed to become a clockmaker with the master, Johann Georg Butzjager of Neulengbach, a small village on the edge of the great Vienna woods.[11] This region was then part of the domain of the Archduke of Austria, of which Sankt Polten was the capital.

[Ill.u.s.tration: Figure 4.--PORTRAIT OF BARTOLOMEO ANTONIO BERTOLLA, clockmaker, of Mocenigo di Rumo. The canvas in oils is owned by descendants. In the upper left-hand corner is an inscription, now hardly legible, indicating that the portrait may have been painted after Bertolla's death on January 15, 1789. Translated, it states: "Bartolomeo Antonio Bertola [sic] Celebrated Mechanician and Inventor of various Instruments. Repairer of the clocks of Venice, Verona, Trent, and other localities. Maker of the Work which combines the Copernican and Ptolemaic Systems devised by Father Frances...o...b..rghesi of Mechel, Laureate Mathematician, and humbly offered to Her Imperial Majesty Maria Theresa. Died in piety in his home at Rumo on 15 January 1789 at the age of 86." (_Courtesy of Sig. Luigi Pippa of Milan._)]

[Ill.u.s.tration: Figure 5.--THE VILLAGE OF MOCENIGO DI RUMO in the valley of the Non. Arrow points to Bertolla's home and workshop at far left.]

[Ill.u.s.tration: Figure 6.--CERTIFICATE OF APPRENTICEs.h.i.+P awarded to Bartolomeo Antonio Bertolla upon completion of his 3-year apprentices.h.i.+p at Neulengbach, dated December 27, 1722.]

Bertolla began his apprentices.h.i.+p with Butzjager under the auspices of the Corporation of Blacksmiths of Sankt Polten in 1719. His training was supervised by two master locksmiths, Johann Christian Winz and Peter Wisshofer, who were members of the Corporation, and were a.s.signed to serve as patrons for the apprentice. It was their obligation to make certain that he received good care and adequate instruction from his master. While he worked in Butzjager's shop, Bertolla lived with the master's family in their home.

Bertolla's 3 years at Neulengbach pa.s.sed quickly as he sought to absorb all that his master could teach him. Butzjager was considered to be a good craftsman in the region, yet today there is not even a mention of his name in the lists of clockmakers. He specialized in the production and repair of "great clocks" which included tall-case, domestic timepieces, and tower clocks. Butzjager treated his apprentice well, and in return Bertolla rewarded him by being diligent and honest. His subsequent work is sufficient indication that he developed into an extremely skilled craftsman, and he became the equal of any clockmaker of his time.

The 3 years of apprentices.h.i.+p were completed and on December 27, 1722, Bertolla received a certificate from the Corporation of Blacksmiths which a.s.sured whomever it might concern of Bertolla's skill, diligence and honesty, and permitted him to open his own shop as a clockmaker under the auspices of the Corporation. This doc.u.ment, which has been preserved by Bertolla's descendants, is an interesting record of the organization of the trade guilds in the 18th century, and, for that reason, has been translated from the original German: