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Transcriber's note:

This is Contributions from the Museum of History and Technology, Paper 35, from the Smithsonian Institution United States National Museum Bulletin 240, comprising Papers 34-44, which will also be available as a complete e-book.

The front material, introduction and relevant index entries from the Bulletin are included in each single-paper e-book.

Corrections are listed at the end of the e-book.

Characters within curly braces following a carat character are superscripted (example: Bart^{o}),

Smithsonian Institution United States National Museum Bulletin 240

Smithsonian Press

Museum of History and Technology

Contributions from the Museum of History and Technology

Papers 34-44 on Science and Technology

Smithsonian Institution . Washington, D.C. 1966

* * * * *

_Publications of the United States National Museum_

The scholarly and scientific publications of the United States National Museum include two series, _Proceedings of the United States National Museum_ and _United States National Museum Bulletin_.

In these series, the Museum publishes original articles and monographs dealing with the collections and work of its constituent museums--The Museum of Natural History and the Museum of History and Technology--setting forth newly acquired facts in the fields of anthropology, biology, history, geology, and technology. Copies of each publication are distributed to libraries, to cultural and scientific organizations, and to specialists and others interested in the different subjects.

The _Proceedings_, begun in 1878, are intended for the publication, in separate form, of shorter papers from the Museum of Natural History. These are gathered in volumes, octavo in size, with the publication date of each paper recorded in the table of contents of the volume.

In the _Bulletin_ series, the first of which was issued in 1875, appear longer, separate publications consisting of monographs (occasionally in several parts) and volumes in which are collected works on related subjects. _Bulletins_ are either octavo or quarto in size, depending on the needs of the presentation. Since 1902 papers relating to the botanical collections of the Museum of Natural History have been published in the _Bulletin_ series under the heading _Contributions from the United States National Herbarium_, and since 1959, in _Bulletins_ titled "Contributions from the Museum of History and Technology," have been gathered shorter papers relating to the collections and research of that Museum.

The present collection of Contributions, Papers 34-44, comprises Bulletin 240. Each of these papers has been previously published in separate form. The year of publication is shown on the last page of each paper.

FRANK A. TAYLOR _Director, United States National Museum_

* * * * *

Contributions from the Museum of History and Technology: Paper 35

THE BORGHESI ASTRONOMICAL CLOCK IN THE MUSEUM OF HISTORY AND TECHNOLOGY

by

SILVIO A. BEDINI

DEVELOPMENT OF ASTRONOMICAL CLOCKS 32

DESIGNER BORGHESI 33

CLOCKMAKER BERTOLLA 34

FIRST BORGHESI CLOCK 38

SECOND BORGHESI CLOCK 41

BORGHESIAN THEORY OF THE UNIVERSE 54

LAST YEARS 57

THE CLOCKS OF BARTOLOMEO ANTONIO BERTOLLA 59

APPENDIX 71

BIBLIOGRAPHY 76

_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 Francesco Borghesi 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 Institution'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 unobscured by clouds, even though I had no astronomical equipment."[1]

With these words, Father Francesco Borghesi (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 multitude of functions, was designed by Father Francesco Borghesi, 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 Institution.

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 documented 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 shifted 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 Matthaeus Hahn (1739-1790) of Wuerttemberg.[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 assistance received from the following: DR. AMOS AVERY, Amherst, Massachusetts; 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 illustrations 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 Nazionale della Scienza e della Tecnica, Milan, for their cooperation on the descriptions and illustrations of the restored clockshop of Bartolomeo Antonio Bertolla; and DR. EDWARD WATERS, Division of Music, Library of Congress, Washington, D.C.

The translation from Francesco Borghesi'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, Washington, D.C.; and REV. DANIEL HUNTER, O.P., and REV. ROBERT STENGER, O.P., Dominican House of Studies, Washington, D.C.

* * * * *

Another of the clerical clockmakers was Father Aurelianus 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 Aurelianus belonged. He achieved note as the author of various publications, including _Neue Raedergebaeude_[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 Francesco Borghesi.

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 Aurelianus, 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 association 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 passage 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.

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 Francesco Borghesi was born in 1723.[8] Local records are meager and inadequate, and many of the details of Borghesi's life must be assumed. 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 assigned 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 parishioners. It was during his assignment 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 Butzjaeger 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 Poelten was the capital.

Bertolla began his apprenticeship with Butzjaeger under the auspices of the Corporation of Blacksmiths of Sankt Poelten in 1719. His training was supervised by two master locksmiths, Johann Christian Winz and Peter Wisshofer, who were members of the Corporation, and were assigned 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 Butzjaeger's shop, Bertolla lived with the master's family in their home.

Bertolla's 3 years at Neulengbach passed quickly as he sought to absorb all that his master could teach him. Butzjaeger 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. Butzjaeger 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 apprenticeship were completed and on December 27, 1722, Bertolla received a certificate from the Corporation of Blacksmiths which assured 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 document, 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:

We, the Superiors and other masters of the honorable corporation of municipal blacksmiths, armorers, and of smiths, in the Imperial City of St. Poelten in Austria by the river Enns, DECLARE BY THESE PRESENTS put in force by this document to anyone who waits to hear.... That the honorable and able BARTOLOMEO ANTONIO BERTOLLA of Rumo in Lentzberg, the Tyrol, on the 27th day of the month of December of the year 1719 was consigned as apprentice for three years, in the presence of two sponsoring masters for the purpose, the honorable Johann Christian Winz and Peter Wisshofer, both of them master locksmiths representing the entire honorable Corporation and others of open shop--to the honorable JOHANN GEORG BUTZJAEGER, incorporated with us, citizen and master clockmaker for large clocks in the merchant-village of Neulengbach in Wienerwald, as his master of the art, would have therefore perfectly and rightfully worked and learned, and

that afterwards, on the day and year noted at the bottom, he will be newly declared free and independent before us, representative of an entire and honorable Corporation and with open shop, of his above-mentioned master and of the two sponsoring masters mentioned,

and since he eagerly requested a truthful certificate of apprenticeship for his honest service as an apprentice and for his good behavior, and we having great pleasure as well as the duty of favoring the truth and well knowing that the aforesaid BARTOLOMEO ANTONIO BERTOLLA has learned honestly the art of clockmaking for great clocks from his aforesaid master, and that he has always behaved with honesty, obedience, faithfulness and diligence both towards his master and towards us to our complete satisfaction and, therefore, we cannot in any manner refuse his request, rather we wish to grant it with a clear conscience.

WE THEREFORE ADDRESS TO EVERYONE and to anyone in whatever state and rank, but particularly to those interested in our branch of this art, our respectful and courteous entreaty and request to consider BARTOLOMEO ANTONIO BERTOLLA well recommended for his honest apprenticeship and his good behavior, and to desire to favor him in every way, in such a manner that will assure our gratitude whenever an occasion presents itself.

For this purpose, we issue, as we have declared we wish to issue to you, BARTOLOMEO ANTONIO BERTOLLA, this certificate of apprenticeship, attaching to it the seal of our Corporation.

Executed in the city of St. Poelten on 27 December 1722.[12]

His apprenticeship over, Bertolla returned to his native region where he soon established a reputation for himself as one of the most skillful clockmakers in the Tridentina and produced timepieces of fine quality in some quantity. No records have survived concerning his personal life, but it is believed that he married probably soon after his return. He had no children of his own. To expand his business, he eventually took into his shop two nephews, the sons of a brother and a sister, as apprentices.

Bertolla's work brought him a sufficient number of clients, and he produced elaborate clocks for his more wealthy patrons.

In 1752, it is recorded that he repaired the great clock in the campanile of the Church of the Assumption of the Virgin Mary in Cles, the regional capital of the valley of the Non. The clock dated probably from the 16th century, and it seems likely that Bertolla replaced the original two-wheel train with a three-wheel movement, and that he added the present anchor escapement.[13]

It is not possible to determine when Father Borghesi first made Bertolla's acquaintance, but it may be assumed that they had become friends in the late 1750's.

After he had come to know Bertolla, Father Borghesi apparently spent many hours in the clockmaker's shop. He was fascinated by mechanics in any form, and the complications of clockwork particularly intrigued him. Bertolla was patient with the young priest, explaining the tools he had and their uses, the clocks he produced or repaired, and the principles which were involved. Father Borghesi listened willingly and as his understanding of timepieces grew, his curiosity increased.

In spite of himself, the priest could not be satisfied with the ordinary aspects of his friend's work and wanted to learn more. From a casual pastime, the study of time became an obsession with him. There was but one recourse: he went back to studying once again. This time it was not theology, however, but the sciences. Every moment he could spare went into the perusal of books on mathematics, astronomy, and associated subjects. He progressed rapidly, driven by his overpowering interest and aided by his quick intellect.