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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
[Illustration]
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
[Illustration: Figure 1.--THE DIAL PLATE of the Borghesi clock, showing
the horary and astronomical indications which are automatically
presented.]
_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.
* * * * *
[Illustration: Figure 2.--PORTRAIT OF FATHER FRANCESCO BORGHESI,
inventor and designer of the astronomical clock in the Museum of History
and Technology.]
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.
[Illustration: 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 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.
[Illustration: 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 Francesco Borghesi 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._)]
[Illustration: 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.]
[Illustration: Figure 6.--CERTIFICATE OF APPRENTICESHIP awarded to
Bartolomeo Antonio Bertolla upon completion of his 3-year apprenticeship
at Neulengbach, dated December 27, 1722.]
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.
Little by little, Borghesi managed to acquire the basic texts that
explained this new world to him, probably borrowing them from old
seminary friends. As each new book came into his hands, he devoured it
in his desire to master its contents. He discussed each new principle or
precept that he learned with Bertolla. Together, they attempted to apply
his new learning to the calculations necessary for a timepiece which
would demonstrate the astronomical theories in visual form. Borghesi
taught himself slowly, step by step, and the result was a profound
understanding of astronomical science. He conceived the project of
constructing a great astronomical clock which he felt could be
accomplished by combining Bertolla's mechanical skills with his own
recent mastery of astronomy and mathematics.
First Borghesi Clock
It is not difficult to visualize the two men, the priest and the
clockmaker, as they sat together night after night working out their
plans. Father Borghesi would painstakingly outline the astronomical
principles he wished to have the clock exhibit and the mathematical
principles which would be involved to operate them. Bertolla
concentrated on them and tried to transcribe the principles into
functional mechanical terms, visualizing each operation in terms of
wheels and gears. Little by little the two men coordinated the numerous
elements and welded them into an operating entity. They adjourned either
to the stark simplicity of the rectory or, probably more often, to
Bertolla's little home workshop, the priest standing over his friend
while the latter worked at his bench in the dark paneled interior
illuminated only by the several lamps on the work benches.
This first clock which the two men combined to create is a monument to
the great scientific knowledge of the self-taught priest and the
technical ability of the clockmaker--a unity combining astronomical
science, mechanics, and artistry. The story of the project is told in a
little book, _Novissima Ac Perpetua Astronomica..._, which Borghesi
later published. Explaining the incentive which inspired him, and the
premises from which he began his work, he wrote:
From the foundation of astronomical science long ago,
innumerable [and] repeated observations of both ancient and
modern astronomers, emerged at last from their hiding places.
Made light of by the jests of so many outstanding intellects,
they have so successfully brought to light the paths of the
stars and their motions, which are more complicated to us than
the Gordian knots. Now it is possible for even an amateur in
astronomy, sufficiently instructed, to predict for any given
time not only the mean position of the planets, but also their
true longitude and latitude, and even the true time of their
conjunctions, and their ecliptic oppositions, with all the
attendant circumstances. Yet, until now, no hypothesis has been
devised which would force an automaton to show to us, before
our very eyes, the eclipses of the planets in their true and
certain times.
For though there have been men seeking with all their might to
bind by laws their artificial heavens, by I know not how many
and how great calculations, and to systematize the complexities
of the rotations of celestial bodies; nevertheless, all of
them, as if by common agreement, considered themselves to have
made great contributions to mechanico-theoretical astronomy.
However, they have only attained, even though closely, the mean
locations of the secondary mobiles, and those by a certain
rather crude calculation. Some attained by more, some by less,
but all by some degree of wandering from the truth, either worn
out by the intricacies of the motions, or deceived and
deceiving by the errors of their calculations. This fact those
well know, who, setting about to collect information of this
kind, even those publicized not long ago, with true
astronomical calculation, have been bored to death while
digging out by the most elementary and superficial arithmetical
torture, the worst of fallacies spontaneously erupting from
thence.
It would seem that true calculations alone can be desired in
mechanico-astronomics. Long study had not only convinced me
that an automaton was within the realm of possibility, but that
there were many mechanical systems by which it could be
achieved. I girded myself for a new project and developed it
theoretically from the ground up, but under such unhappy
auspices that not only did all hope fail that anyone would ever
appear who might have seemed willing to set his hand to the
work, but that the new discovery itself was scoffed at by many
as altogether a nightmarish delirium of an unbridled
imagination.
The first months of the project must have seemed like an inspired dream
to the two men, and then must have followed a period of hopeless
depression. Bertolla undoubtedly felt many times that the clock was an
aspiration far beyond their combined abilities and means, but the priest
would not be thwarted in his ambition and refused to abandon the
project. He felt that it was a work that they were destined to produce.
Many times, he wrote, he chided and begged and shamed his erstwhile
partner into resuming the project where it had been last abandoned.
Little by little, the first clock began to take form. As each new
difficulty was encountered, the two men would go back over the notes and
sketches to trace the problem to its source. Often a new part of the
mechanism would nullify another which had thus far operated
successfully, and a complete rearrangement would be required.
[Illustration: Figure 7.--TITLE PAGE of Father Borghesi's first book.
The translation in its entirety is: "The Most Recent, Perpetual,
Astronomical Calendar Clock: Theoretical--Practical: by means of which
besides the hours, the minutes and seconds; the current year, the month;
the day of the month and the day of the week; the dominical letter,
epact, and thence, the day of all the feastdays, both fixed and movable;
the solar cycle; the golden number; the Roman indiction; the dominant
planet of any year and its sign; the phases of the moon and its mean
age: and all the motions of the sun and the moon as to longitude,
latitude, eccentricity, etc., are immediately seen, so accurately that
[not only] the true new full moons and the true quadrature, etc., of the
sun and moon appear, but also, all solar and lunar eclipses--both
visible and invisible; as in heaven, so on the clock, they are
conspicuously celebrated in their true times, and those of the past and
those of the future, with their circumstances of time and duration,
magnitude, etc., can be quickly determined. All this was devised and
brought to light by the author, Francesco Borghesi of Anauni, a secular
priest of Trent, A.A.L.L. & Doctor of Philosophy. (Trent: From the
printshop of Giovanni Battista Monauni, With Permission of Superiors.)"
(_Title page reproduced by permission of the Biblioteca della Citta di
Trento._)]
Again and again, Bertolla threw up his hands in despair and begged
Father Borghesi to abandon the enterprise. He protested that he was not
capable of producing such a complicated mechanism; he had neither the
tools nor the skill. The priest wished to produce a clock such as the
world had never seen before, such as the greatest scientists and
clockmakers of all time had never been able to make. But Bertolla felt
that he was only a provincial craftsman who could not hope to surpass
them all with only his simple tools and training.
In his book on the first clock, _Novissima Ac Perpetua Astronomica..._,
Father Borghesi wrote that when he had finally come within a few weeks
of the embryo stage in the development of his clock, he was faced with
the problem of bolstering the sagging enthusiasm of Bertolla. The
clockmaker's original enthusiasm had shown promise of great results, but
as the days passed and the problems of the multiplex and generally
unfamiliar apparatus to be forged for the workings of the automaton
became more complex, his ardor decreased. Finally, Bertolla became so
discouraged by the scoffers and frustrated by the fact that the work was
insufficiently organized that Father Borghesi wrote that "it almost
became a harder task for me to bolster up by daily opportunity and
importunity the failing patience of the artisan, frightened away from
the work already begun, than it was for me to extract from the inner
recesses of mathematics and astronomy, without light and without a
guide, the whole fabric of the machine itself!"
In spite of Bertolla's protests, Father Borghesi prevailed, reviving his
friend's interest once more until the two were deep in the project
again. Months passed as they worked together on the mechanism and it
seemed as if they lived for no other purpose. Inevitably, Bertolla's
health began to suffer, undermined as it was by the constant nervous
tension, and he eventually became ill from mental strain. He was forced
to spend some time in bed, and for many weeks the subject of the clock
was not discussed. Bertolla's other work, by which he made his living,
suffered and it was several months before he was able to return to his
little shop.
One year passed into another and the work progressed slowly. The first
clock, which easily should have been finished in less than a year, was
not completed until after three full years had passed. However, when the
priest and the clockmaker put the finishing touches to their great
clock, the result surpassed the greatest possible expectations, for it
was truly a masterpiece. Not only did it illustrate the ecliptic
phenomena of the moon, the sun and earth occurring in their proper time,
as well as many other things, but it showed these operations as they
succeeded in proper order, taking place through the centuries.
With mutual feelings of great pride, the two friends surveyed the result
of their three years of endeavor. Bertolla realized that he had reached
a point of maximum achievement in his work. He probably felt that now he
could relax again, that his sleep would no longer be troubled by
confused nightmares of wheels and gears that did not mesh together. Time
was to prove otherwise.
PUBLISHED DESCRIPTION OF THE FIRST CLOCK
Father Borghesi soon came to the conclusion that it would be desirable
to have a written description to explain the mechanism of the clock and
its many indicators. He thereupon wrote out the story of how the clock
was made, the reasons for embarking on the enterprise, the difficulties
he had encountered, and the success which had crowned his and Bertolla's
mutual labors. Finally, he described the operation of the clock's
mechanism and the functions of its array of indicators.
The little book was written in Latin and only a few copies were printed,
presumably at the priest's own expense, on a handpress by Giovanni
Battista Monauni, printer to the Bishop in Trent. The little volume was
stated by contemporary writers to have been published in 1763, although
no date appears on the title page. The title translated is, in part,
_The Most Recent, Perpetual Astronomical Calendar Clock,
Theoretical--Practical...._ The work begins with an introduction for the
reader in which Father Borghesi stated that:
... the little work, which, as far as I was concerned could
easily have been finished in a year, was only completed after
about three years. Fortunately, however, it was so far beyond
the expectations of most, that not only am I able to foretell
with certainty all the lunar ecliptic phenomena and the solar,
or rather terrestrial, phenomena, carefully worked out in their
true periods, among many other matters exhibited by the
machine; but also, within a few hours, I can exhibit by
altogether tangible evidence to the skeptics and the doubting
those very same phenomena, occurring within the space of many
years, or even centuries, and succeeding one another in proper
order, with their many attendant circumstances. I was not much
concerned about the other eclipses, such as those of Mercury,
Venus, and the other stars wandering through the zodiac, or
about the other solar eclipses from the transit of Mercury or
Venus, since they are altogether undiscernible to the naked
eye, and very few compilers of ephemerides wish them to be
noted, probably for the same reason.
Do not, however, expect, star-loving reader, that here anything
at all that you may wish can be drawn forth as from its source,
for to demand this would be almost the same as to seek to drain
as from a cup all the vast knowledge of the many arithmetical
sciences from the narrow confines of one book. You will
understand how impossible that is when, through prolonged
labor, you have grown somewhat more mature in this kind of
learning.
Wherefore, rather fully, and out of consideration for you, I
have decided, setting aside these prolixities, with completely
synoptic brevity and with all possible clarity to expound for
you simply the proportion of the movements, the description of
the machine, and its usage. As a result, when you have
progressed a little in theoretical mechanics, you will not only
be able to reduce all these things to their astronomical
principles, but you may find the way more smoothly laid out for
you even for perfecting the machine itself. And, thus, you may
be more effectively encouraged to a successful conclusion. Let
it be so now for you through the following 10 chapters!
After these rather hopeful assurances, Father Borghesi proceeded to
provide a detailed description of the clock dial and functions in the 10
short chapters which he had promised, under a separate section entitled
"Synopsis Totius Operis Mechanici," which is translated in its entirety
in the appendix.
As Father Borghesi prepared his little volume about his first clock, and
described its unusual features and outlined its functions, which were
primarily to place in evidence the celestial constellations, it occurred
to him that it would now be easier after the experience he had acquired
with his first timepiece, to construct another clock, which would
present the motions of the two astronomical systems, the Ptolemaic and
the Copernican. In this first book, he promised the reader that he would
undertake the second project. It is fortunate that Father Borghesi
undertook this project for the second clock is the only example of his
work that is known to exist today. Extensive research has not shown what
happened to the first clock, although several sources state that both
timepieces were presented to Empress Maria Theresa sometime between 1764
and 1780.
Second Borghesi Clock
Father Borghesi lost no time in initiating the project of the second
clock. The first and most important step was to inform Bertolla and
enlist his assistance. Bertolla was adamant: he had had enough of
complicated astronomical movements. He was delighted by the prospect of
returning to his former simple life, producing simple, domestic,
elementary movements for his country clients. Father Borghesi begged and
cajoled. The second clock would be a much simpler one to construct, he
persisted. After all, they had gained invaluable experience from the
production of the first clock. Furthermore, he had already completed its
design.
Bertolla apparently wavered in his resolve and, unwillingly and against
his better judgment, he allowed the priest's inducements to prevail.
Once again, the two friends yielded their leisure hours to a study of
the priest's books and drawings as Father Borghesi enthusiastically
elaborated his design for the timepiece, and Bertolla attempted to
transcribe astronomical indications into terms of wheel counts. The
second clock was, as Borghesi had promised, much easier of execution.
Within a year, it was completed and functioned with complete success.
[Illustration: Figure 8.--THE BORGHESI CLOCK in the Museum of History
and Technology, constructed in 1764 by Bartolomeo Antonio Bertolla of
Mocenigo di Rumo from the designs of Father Francesco Borghesi of Rumo
and Mechel.]
[Illustration: Figure 9.--ANOTHER VIEW of the Borghesi clock.]
This is the clock now in the Museum of History and Technology. It is
housed in a tall case of dark-red mahogany veneered on oak, with
restrained carving featuring ribands and foliate motifs. Gilt-brass
decorations flank the face of the hood, which is surmounted by three
gilt-brass finials in the form of orbs. A wide door in the waist may be
opened to attend the weights. The case is 7 feet 8 inches high, 20-1/2
inches wide at the waist, and 14 inches in depth.
The dial is of gilt brass, measuring 21 inches high and 15 inches in
width, with a number of supplementary silvered dials visible through its
openings. Instead of hands, the dial utilizes three concentric rings
moving around a central disc, the indications of which are read at two
bisecting gilt lines inscribed in the glass face. Twelve separate
functions are performed by the chapter ring assembly alone, and there
are 14 openings on the dial. It is estimated that the clock performs 30
separate functions, including striking and chiming. Of the multiple
chapter rings, the outermost is 1-1/8 inches wide, the center ring is
3/8 inch wide, and the innermost ring measures 1-1/4 inches in width.
THE DIAL-PLATE ENGRAVINGS
The gilt dial is incised throughout with figures and inscriptions in
engraving of the very finest quality, as is evidenced in the
illustrations. The frontispiece is surmounted at its center by the
crowned double eagle of the House of Hapsburg, indicating the identity
of the sovereign in whose reign it was made, Emperor Francis I or the
Empress Maria Theresa of Austria. Below the eagle at either side are
flying cherubs supporting ribands with inscriptions. Centered at the
bottom of the frontispiece immediately above the chapter rings is the
moving silvered orb representing the sun. Surrounding it is a tableau of
the Holy Trinity, with the Virgin Mary being crowned by Christ holding a
cross at the left and God with a sword in hand at the right, and a dove
representing the Holy Spirit hovering over the Virgin's head. Father S.
X. Winters, S.J., considers it reminiscent of the triptych "The
Coronation of the Virgin" by Fra Lippo Lippi.
[Illustration: Figure 10.--DIAGRAM OF the dial plate.]
[Illustration: Figure 11.--DIAL PLATE of the Borghesi clock.]
KEY TO DIAGRAM OF THE DIAL PLATE
A Dominating planet, represented by its symbol and its house;
B Dominical letter (Lit. Dom.);
C Epacts (Cyc. EpEC);
D Roman indiction (Ind. Rom.), part of the reckoning of the Julian
period;
E Solar cycle, (Cyc. Sol.), part of the reckoning for the Julian period;
F Golden number (Num. Aur.), part of the reckoning for the Julian
period;
G, H, I, J The era, or the current year; part of the six windows of the
Iris, or rainbow;
K Shuttered winding hole, for winding up the weights; part of the six
windows of the Iris;
L The era, or the month of the current year; part of the Iris, or six
windows of the rainbow;
M The sun in its epicycle;
N The 12 signs of the sun's anomaly;
O, P The first chapter ring representing the equatorial globe of the
week, revolving from left to right;
Q The coming day indicated through the window;
R The second chapter ring; including the synodic-periodic measure of
the tides, the days of the median lunar-synodic age, the signs and
degrees of the signs for mean distance of the moon from the sun;
S Epicycle of the moon with signs of its anomaly;
T Head of the dragon (Cap. Draconis);
U Tail of the dragon (Cauda Draconis), for measuring eclipses of the
earth and of the moon;
V Third chapter ring, with degrees of lunar latitude and some fixed
stars;
W Fourth chapter ring, showing firmament of fixed stars, signs of the
zodiac and degrees of the signs, the months of the year, and days of the
months, revolving left to right for the course of a mean astronomical
year;
X Adjustment marked _Claudit_ (it closes) and _Aperit_ (it opens) for
disengaging dial work for the purpose of making astronomical experiments
and computations;
Y Adjustment marked _Concitat_ (it accelerates) and _Retardit_ (it
retards) for fast and slow adjustments of the movement.
In the upper spandrels of the dial are two more cherubs bearing ribands
with inscriptions. In the lower left corner is a magnificent engraving
of Atlas upholding the globe of the world, inscribed with the zodiac,
over his head. The lower right corner features the figures of two
noblemen apparently examining and discussing an orb upon a table, the
significance of which is not clear.
[Illustration: Figure 12.--EMPRESS MARIA THERESA, to whom Father
Borghesi is stated to have presented his two astronomical clocks. The
coin bearing her portrait is in the Museum of History and Technology.]
THE INSCRIPTIONS
Beginning with the uppermost part of the frontispiece, there are nine
inscriptions in Latin on the dial plate. The topmost is _Franciscvs I
sit plan. Dominator aeternvs._ The phrase has reference to Francis I,
who was Emperor of the Holy Roman Empire, from 1745-1765, and husband of
Empress Maria Theresa of Austria. The phrase may be translated as "May
Francis I be the eternal ruler by favor of the planets" or more simply
"Long Live Francis I, Emperor."[14] Although the dial plate of the
Borghesi clock is inscribed with his name, the records indicate that
the clock was presented to Maria Theresa. Francis I may have already
died before the presentation was made.
[Illustration: Figure 13.--PORTRAIT OF FRANCIS I, Emperor of the Holy
Roman Empire, to whom Father Borghesi's astronomical clock in the Museum
of History and Technology appears to have been inscribed.]
From the left to right over the tableau of the Holy Trinity is the
phrase "Lavs sacrosanctae Triadi Vni Deo, et Deiparae" (Praise [be] to
the most Holy Trinity, to the one God, and to the Mother of God).
Within the upper left and right spandrels is inscribed:
Isthaec, Signum grande apparvit in Coelo * sancta Dei genitrix
amicta sole * Illibato pede Lvnae et serpentis nigra premens
Cornva * bis senis pvlcherrime Coronata syderibvs * Tempe
indesinenter clavsa, scatvrigo signata * Cedrvs in Libano,
Cypresvs in Monte Sion * Mater pvrae Dilectionis sanctaeqve
spei * Chara patris aeterni proles, Verbi Mater, sponsaqve
procedentis *, gratiae et gloriae circvmdata varietate.
This inscription is a eulogy to the Virgin Mary assembled from the texts
of Holy Scripture. In addition, each _lemma_, contained within
asterisks, carries out the chronogram 1764, the year the clock was
completed. Each _lemma_ is translated and identified from the
Douay-Rheims version of the Bible:
This woman: a great sign appeared in Heaven (Apocalypse 12:1) *
The Holy Mother of God clothed with the sun (Apocalypse 12:1) *
And with unharmed foot crushing the black horns of the moon
(Apocalypse 12:1) and the serpent (Genesis 3:15) * Most
beautifully crowned with twice-six (Apocalypse 12:1) * A garden
[_Tempe_[15]] enclosed, sealed with a fountain [spring of
water] (Song of Songs 4:12) * Like a cedar in Lebanon, and a
cypress tree on Mount Zion; (Ecclesiasticus 24:17) * Mother of
pure love and of holy hope: Beloved daughter of the Eternal
Father, Mother of the Word, Spouse of the Holy Spirit:
(Ecclesiasticus 24:24) * Surrounded with a diversity of grace
and glory (Psalms 44:10).
[Illustration: Figure 14.--THE BOTTOM RIGHT CORNER of the dial plate,
showing two noblemen contemplating an orb, with the inscription "Diligit
Avdaces Trepidos Fortvna Repellet." (Fortune favors the daring and
rejects the timid.)]
At the lower left corner below the figure of Atlas upholding the world
is the phrase, _Assidvo proni donant di cvncta labori_. (The favorable
gods willingly grant all things to the assiduous laborer.) The same
phrase is quoted by Father Borghesi in the text of his second volume.
The last inscription appears at the lower right corner under the figures
of the two noblemen, _Diligit avdaces trepidos fortvna repellet_.
(Fortune favors the daring and rejects the timid.) The last two
inscriptions are in dactylic hexameter. They appear to be original
compositions inasmuch as no classical prototypes have been identified.
[Illustration: Figure 15.--THE BOTTOM LEFT CORNER of the dial plate,
showing the engraving of Atlas, with the inscription "Assidvo proni
donant di cvncta labori." (The favorable gods willingly grant all things
to the assiduous laborer.)]
CENTER DIAL INSCRIPTIONS
[Illustration: Figure 16.--DETAIL OF FRONTISPIECE of the Borghesi clock,
showing the apertures for calendar indicators and the details of the
engraving.]