Smithsonian Institution - United States National Museum - Bulletin 240
introduction to the reader, and in it Father Borghesi proposed:
6235 words | Chapter 6
That you might rightly conceive my new system of the world and
mechanically, as it were, construct it, imagine for yourself,
beneath that most happy seat of the Blessed and above all other
heavens, a kind of spherical convexity, everywhere equidistant
from the center of the earth, and endowed with absolutely no
motion.
On the inside, at two points diametrically opposite each other,
this convexity has two most sturdy poles (to speak
mechanically), projecting towards the center (which you call
the poles of the heavens), and the largest immobile semicircle,
in some manner is drawn from the center of one pole to the
center of the other. This semicircle in the middle, namely at a
point equidistant from each pole, is thought to be secured by
some sign, for example, by that "o," for arranging more
perceptibly the seat of the sun (as will be shown later). This
much must be conceived first.
You must understand that imposed on these poles is the first
mobile [Primum Mobile], everywhere convex, and divided, into 12
equal parts [Dodecatemoria], by the 6 greatest circles,
intersecting each other at the centers of the poles. Then it is
divided by another equally great circle, everywhere equidistant
from the poles, into two hemispheres. One hemisphere of 12
parts, proceeding in order from west [setting] to east [rising]
should be assigned the respective signs of the zodiac; that is,
one to Aries, the next to Taurus, and so on, etc. The circle
which cuts those 12 parts transversely in the middle, you call
the ecliptic. Then, these capital spaces of the Primum Mobile
are subdivided by degrees, minutes, etc., both in longitude and
in latitude, so that this heaven represents a kind of great
spherical net, extended to capture the longitude and latitude
of the stars, and Mobile on the aforementioned poles. Note,
however (and this is almost the leading point of the system),
in that circle of longitude which divides the sign of Gemini
from Cancer and Arcitenens [Sagittarius] from Capricorn, you
must conceive two points, directly opposite each other and
removed about twenty-three and a half degrees from the poles:
Boreal [the northern] between Gemini and Cancer; Austral [the
southern] between Sagittarius and Capricorn. These two points
by some power (imagine it is magnetic power), equal between
them, hold the terraqueous orb suspended in the middle, by
acting on the axis of the same orb (imagine it is iron) in such
a way that the earth is continually drawn to those two points
as to two opposite centers. It is never nearer to one, for as
it is about to move towards one, the opposite power is
constantly drawing it back. Thus, both those points and the
axis of the earth are always held in one common line, wherever
those points happen to be carried by the rotation of this
heaven.
Again, it is necessary for you to conceive in this heaven,
first, two great circles, bisecting each other at right angles
in the centers of these two magnets. One of these circles,
passing through the first point of Aries and Libra in the
ecliptic, is called equinoctial colure: the other circle,
passing consequently between the first point of Cancer and
Capricorn, is called solstitial colure. Beneath these are
likewise imagined many other great circles, in the centers of
the magnets dividing crosswise in the shape of an "X." But if,
receding from these magnets, you describe circles (parallel to
each other and ever greater and greater, up to the greatest
circle which you will perceive is called the equator),
equidistant from each magnet and obliquely splitting the
ecliptic in the equinoctial colure, you can then behold a
great, new, woven net in this heaven of the Primum Mobile. This
net most beautifully expands to extract the straight ascent and
descent of the stars, etc., from the vast ocean of the heavens,
catching the straight ascent in the greatest circles and, in
other unequal circles, parallel to each other and obliquely
cutting across, most safely catching the descent.
Immediately below the Primum Mobile place the heaven of the
fixed stars (and, that the idea might be clearer), revolving
separately on the same poles on which the Primum Mobile
revolves. Through this heaven, the filaments of the little
nets, etc., seem to the eyes of you on earth as if they shine.
In this heaven, you should conceive in their fixed places, the
fixed stars, a proportionate, inviolable distance from each
other, and, indeed, if you will, the heavenly images, etc.,
depicted, and all carried along at the same time with their
heaven by one motion.
Conceive a straight line running from the center of the earth
to that sign "o" noted in the semicircle of the supreme
immobile heaven. On this line, greatly below the heaven of the
fixed stars, place the center of the solar epicycle, holding an
area in common with the ecliptic and subject to absolutely no
motions, but at such a distance from the center of the earth
that the semidiameter of the earth has little, if any,
proportion with the distance of the solar epicycle from the
earth. Around the sun, moving continually in this epicycle (its
immobile palace) through the degrees of the anomaly, you can
revolve, with motions proportionate to the system, the five
planets: Mercury and Venus (the nearest barons of the sun),
then Mars, Jupiter and, most remote, Saturn, with its
respective satellites, etc., eccentrically surrounding the
earth itself and the moon in their immense ambit and wandering
by their proper motions through the zodiac.
Nevertheless, not far from the earth you should imagine
fabricated, as from most refined crystal, the heaven of the
moon everywhere equidistant from the center of the earth and
revolving separately on the same poles (prolonged even to this
place) on which the Primum Mobile and the heaven of the fixed
stars revolve. In the middle of this, that is, in some point
equally removed from the poles, you place the center of the
lunar epicycle, movable also by the common rotation of the
lunar heaven. I refrain from the other movements of the moon in
latitude, etc., as also those of the five planets, etc., which
the theory in no way excludes, lest by a variety of congested
motions explained too abundantly, either you might be confused
about the fundamental concept of the system or, while adorning
the theory and trying to embellish the least things more
widely, you might reject also the things which are capital.
Here you already have the whole machine, but still inert and to
be animated for the first time by motions accommodated to the
system. Nevertheless, before I assign motion to the individual
parts of the world, so that the thing might later appear more
clearly to you, I arrange all things thus: first, as if by
hand, I turn the Primum Mobile until the Boreal magnetic point
comes to the level or the area of the semicircle described in
the supreme immobile convexity; then I turn the heaven of the
fixed stars until, for example, the heel of Castor (a star of
the third magnitude), almost in the ecliptic and indeed in our
time not far distant from the solstitial colure, likewise falls
nearly at the level of the aforesaid semicircle. Later, I turn
the lunar heaven until I bring the center of the lunar epicycle
to the same level. Then, I turn the earth until some
predetermined city, for example, Trent, situated in the
northern zone with a latitude of about forty-six degrees, is
brought to the oft-mentioned level.
From things arranged in this way and from what has gone before,
it is evident (with the motions of the luminaries in epicycles
left out, however, lest you be distracted by the explanation)
that at Trent, just as in the whole northern hemisphere, it is
the summer solstice; and, conversely, in the southern
hemisphere, it is the winter solstice. The reason is because
the northern magnetic point together with the northern half of
the earthly axis is at its highest point towards the sun,
immovably residing in a line sent through the level of the
highest semicircle; and, conversely, the southern magnetic
point with the corresponding half of the axis is most removed
from the same. It further follows, that noonday and the new
moon coincide, and the heel of Castor almost reaches the
summit, etc.
Now, beginning from this hypothetical situation of the whole
world as from the root of the motions, I move all things in
their circles so that the earth turns on its axis with a
revolving motion from west to east in each 24 hours of median
time. The lunar heaven completes one circle around its poles
likewise from west to east in the time of 29 terrestrial
revolutions, hours 12.44.3.13.1. The sphere of the fixed stars
on the same poles revolves once from east to west within 365
revolutions of the earth, hours 6.9.29.1. The Primum Mobile on
the poles (common to the heaven of the fixed stars and the
heaven of the moon), is moved once in the same way from east to
west, a little faster, however, than the heaven of the fixed
stars, yet within 365 revolutions of the earth, hours 5.48.56;
that is, within a median astronomical year.
Now, behold for yourself a new world supported on new poles and
provided with new motions and laws. Now you, reader and lover
of the stars, turn it, and revolve it as long as it pleases
you, and compare it astronomically and physically with the
Copernican or the Tychonian systems or with whatever one
pleases you more, and judge which one seems more consonant with
nature when all things are examined. But if you aren't able to
reconcile this theory with some astronomical observations or
physical experiments and think it should be eliminated from
the group of theories, see that I might know this while life is
still my companion, so that I might think with you, if this is
possible. Also, so that, in gratitude for the detected or
perhaps hidden error, I might speak or write, and you won't
have to shout in vain in bold ridicule and with no applause
after the fleeing shades of the dead and the mute ashes. But,
if you object that the daily motion of the revolving earth and
the annual motion of its whirling axis do not sufficiently
agree with certain texts of Sacred Scripture, and if those
things which the Copernicans and the Longomontanists say do not
convince you, then reject my whole system as an old wives'
tale.
* * * * *
GLOSSARY
ANOMOLIA or anomaly, is the angular distance of a planet from its
perihelion (that point of the orbit of a planet which is nearest to the
sun) as seen from the sun.
AEQUINOCTIUM or the equinox, is the time in which days and nights are
equal in the space of hours. There are two equinoxes: the spring
equinox--c. 8 calends of April in the sign of Aries; and the fall
equinox--c. 10 calends of October in the sign of Libra.
AERAS is derived from _aera_, _aerae_, which originally meant a given
number, usually used in regard to money. The word was later extended to
mean a number used in any calculation, and finally it came to mean a
certain time from which subsequent times were counted, e.g., _Anno
Domini_, after the Birth of Christ.
COLURI or the Colures, which are two circles in the heavenly sphere,
passing through the poles of the world and cutting each other at right
angles: the one passes through the equinoctial points of Aries and Libra
and is called _Colurus Aequinoctiorum_ or equinoctial colure; the other
touches the _solstitialia_ of Cancer and Capricorn and is called
_Colurus Solstitiorum_ or solstitial colure. They are called _Colurus_,
which is translated as "mutilated tails," for the part which emerges in
the Antarctic is not visible and is quasitruncated.
ECLIPTICA or the ecliptic, is an imaginary line in the heavens in which
the sun was supposed to have performed its annual course.
EPICYCLUS or epicycle, is a small orb which, being fixed in the deferent
of a planet, is carried along with its motion and yet, with its own
peculiar motion, carries the body of the planet fastened to it round
about its proper center.
IRIS or the rainbow. In mythology, Iris was the daughter of Thaumatis
and Electra, messenger of Juno of the goddesses and Jove of the gods.
SOLSTITIUM or the solstice, is that time when the sun seems to stand
still for a short time: when the sign of Cancer enters the month of June
(equivalent to the summer solstice, when the sun begins to recede from
us); and when the sign of Capricorn enters the month of December
(equivalent to the winter solstice, when the sun begins to accede to
us).
* * * * *
Last Years
There is a break in the story of Borghesi and Bertolla for the next five
years. The second clock may have been the last project on which the
priest and the clockmaker worked together, for very good reasons. The
two clocks must have represented a considerable financial investment in
materials and in time, and neither of the men was in sufficiently
affluent circumstances to undertake the luxury of such a hobby without
some form of recompense. The publication of the two little volumes must
have also been done at Father Borghesi's expense. The income of the
parish priest in a small mountain village could not have been equal to
the relatively great costs of the projects that had been completed. It
seems probable that the priest attempted to sell his clocks to a wealthy
patron, perhaps the Baron of Cles, or he may have attempted to obtain
some form of recompense for the continuation of his research. However,
no records can be found of such patronage if it existed. If Borghesi had
received financial assistance while the projects were in progress, he
would certainly have made adequate mention of the patron's name and
assistance in one or the other of the two volumes which he
published.[17]
The next record relating to Borghesi which has been found is the
description of a letter written by an anonymous mathematician late in
1768 or early in 1769. It was 28 pages in length, written in Latin, in
the form of a reply to the writer's brother, on the subject of the clock
invented by Borghesi. It consisted primarily of a criticism launched
against Borghesi's first little volume published in 1763.
The anonymous letter is without date, place, or signature. This writer
claimed that Father Borghesi had made many errors in his book,
presumably in the description of the clock's functions, and in the basic
theories upon which the priest had predicated his research. No complete
copy of the letter's text has been found for study, although it is
described at length in Tovazzi's _Biblioteca Tirolese_. Tovazzi noted
that four copies of the letter existed at that time, and that he
personally had filed one in the Biblioteca di Cles in Trent. However,
every attempt to locate a copy at the present time has been
unsuccessful.
If the anonymous letter was brought to the attention of Father Borghesi,
it must have introduced a disturbing note into his life and cost the
priest many unhappy moments. He was not, however, dissuaded from his
preoccupation with horology. Several years later, in 1773, Father
Borghesi was working on yet another astronomical clock, this time
presumably without the assistance of Bertolla. This third clock was
reported by Tovazzi to have been "of minimum expense but of maximum
ingenuity."
No subsequent information relating to it has come to light, and there is
no record that it was actually completed.
Again there is a period of silence in the life of Father Borghesi which
no amount of research has yet been able to pierce. Whatever the
circumstances may have been, it is reported by several of the sources
noted that both the first and the second clock did, in fact, become the
property of the Empress Maria Theresa in Vienna. The presentation was
made sometime during the period between the completion of the second
clock in 1764 and the year 1780. There is some discrepancy in the
contemporary accounts as to whether Father Borghesi presented one or two
clocks to the Empress, but all the sources with but one exception record
that both clocks were acquired by the Empress.
It is doubtful that Father Borghesi had originally intended to give his
clocks to the Empress at the time that they were made, for he would most
certainly have made some mention of such an intention in the two little
volumes which he published about them. If he saw the letter published by
the anonymous mathematician in late 1768 or 1769, it is possible that he
decided to make the presentation in expiation of his sense of guilt for
the amount of his time which the creation of the timepieces had
consumed. On the other hand, it is just as possible that Father Borghesi
may have forwarded copies of his two little volumes to the Imperial
Court at Vienna, and that the Empress expressed a desire to acquire the
clocks.
Father Tovazzi states that in 1780 "the clock invented by him [Borghesi]
was preserved in Vienna, Austria, at the Imperial Court from which the
inventor was receiving an annual pension of 400 florins." No records in
the Palace archives relating to the clock have yet been found, nor
records of payment of an annuity to Father Borghesi. However, a more
exhaustive investigation of the Furniture Depository of the Imperial
Court may bring forth related records. It was the implication in Father
Tovazzi's account that the second clock had been presented to the
Empress prior to the publication of the anonymous, critical letter in
1768 or 1769. He believed that it was envy of Father Borghesi's
ingenuity, fame and financial benefit that had caused the anonymous
mathematician to publish his letter, for Tovazzi asked "Who would have
encountered opposition to such a marvel? Envy is not yet dead, and has
always reigned."
This last-mentioned theory about the presentation may be the most likely
one. Some evidence may be found in the second clock itself which bears
out this assumption. The multiple chapter ring, with its many
inscriptions, is engraved and silvered in a relatively crude manner,
presumably by Bertolla himself. The main dial plate, however, which is
of gilt brass, is engraved with the utmost skill by one of the great
masters of the art. The inscription below the Imperial Hapsburg eagle
relates to Francis I, Emperor of the Holy Roman Empire. It is entirely
possible that although Father Borghesi originally had no intention of
giving the clock to the Emperor or the Empress at the time that it was
made, he later changed his mind. Accordingly, he may have commissioned a
master engraver, possibly in Trent or in Vienna itself, to produce a
dial plate which would be of such a quality as to be worthy of the
Emperor himself. If so, this was done shortly after the clock was
completed, for the Emperor died in August of the following year. Perhaps
by the time that the clock was ready, the Emperor had already died, and
Father Borghesi gave the clock instead to Maria Theresa without revising
the inscription.
The acceptance of the clocks by the Empress, and the annuity which was
his reward, would have constituted considerable honor even for one of
the foremost clockmakers of the Empire, but for a humble parish priest
in a little village, such notable Imperial recognition was overwhelming.
Possibly as a result of it, a change was noted in Father Borghesi in the
next few years. His conscience began to bother him, and he began to
question whether he had done right in spending so much of his time and
thought on his horological research. He became more and more confused in
his own mind. Had he spent too much time in mechanical studies to the
neglect of his ecclesiastical duties? If this had been the case, he had
committed the most grievous sin.
Exaggerated though these thoughts may appear, they were undoubtedly of
the most critical importance to the middle-aged priest. His mental
turbulence and confusion increased daily, and it soon became apparent to
others around him. By June 1779, he was completely in the grip of his
obsession, and his parishioners began to whisper amongst themselves that
their pastor was being tortured by the devil. They were unable to help
him, and he became more and more preoccupied with his problem. The years
passed slowly as the pastor became more vague and more tortured by his
conscience.[18]
There probably was continued contact between Father Borghesi and
Bertolla for at least some time after the development of his illness.
Bertolla had retired from active work, but continued to pursue his
interests in his clockshop as much as his health and advanced years
permitted. A clock which he made at the age of 80 survives and is
described and illustrated in the following section on "The Clocks of
Bartolomeo Antonio Bertolla." Finally, on January 15, 1789, Bertolla
passed away and Father Borghesi was left alone, deprived of the
companionship he had enjoyed with the older man for the past two or
three decades. One of Bertolla's nephews continued to work in the master
clockmaker's workshop, but there did not appear to be any association
between the younger man and Father Borghesi.
At last, in 1794, Father Borghesi lost his sanity completely, and he was
forced to relinquish his pastoral duties to a curate. For the remaining
eight years of his life, he continued to live in the rectory of the
little parish church in Mechel where most of his life had been spent,
his needs undoubtedly attended by the parishioners he could no longer
serve. During this period, until his death at the age of 79 on June 12,
1802, Father Borghesi lived on, oblivious of those around him.
Seemingly, he retired to another world; perhaps to that universe which
he had tried to reproduce in his second clock.
The Clocks of Bartolomeo Antonio Bertolla
The ingenuity displayed in the Borghesi clock by its constructor,
Bartolomeo Antonio Bertolla, requires a consideration of the other
examples of his work that have survived. The most important of his
clocks are probably the one in the Episcopal Palace at Trent and another
made for the Baron of Cles.
The one which survives in the Episcopal Palace to the present time, is
extremely tall and is housed in an elaborately decorated narrow case of
black or ebonized wood approximately 9 to 10 feet in height. The upper
part of the case is decorated with elaborately carved and gilt rococo
motifs. The movement operates for one year at a winding, indicates and
strikes the hours, and shows the lunar phases. It has an alarm, and will
repeat the strike at will, indicating the number of the past hour and
the quarters. The gilt brass dial is decorated with silver-foliated
scrollwork in relief at the corners, inside the chapter ring, and within
the broken arch. Featured above the chapter ring is the coat of arms,
executed in silver, of the patron for whom the clock was made,
Cristoforo Sizzo di Noris. Di Noris was Bishop of Trent for 13 years,
from 1763 to 1776.
The clock which Bertolla made for the Baron of Cles is a tall, narrow,
case clock of ebony or ebonized pearwood which is approximately 9-1/2
feet in height. The decoration of the case is considerably more
conservative than the one made for Di Noris, but the black wood is
decorated with silver trim and carved designs in the wood itself. The
dial is decorated with silver scrollwork and spandrels within and around
a raised chapter ring. The clock operates for one month at each winding,
has an alarm, indicates and strikes the hours, and will repeat the
quarters. This handsome timepiece is still in the possession of the
descendants of the Baron of Cles.
[Illustration: Figure 21.--TALL-CASE CLOCK BY BERTOLLA in the Episcopal
Palace in Trent, made for Bishop Cristoforo Sizzo di Noris. A striking
and repeating clock with lunar phases. (_Courtesy of Museo Nazionale
della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 22.--INTERIOR OF BERTOLLA'S WORKSHOP, showing
detail of ceiling. (_Courtesy Museo Nazionale della Scienza e della
Tecnica, Milan._)]
[Illustration: Figure 23.--INTERIOR OF BERTOLLA'S WORKSHOP, showing the
main workbench and the collection of clockmakers' tools. (_Courtesy of
Museo Nazionale della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 24.--FUSEE CUTTER used by Bertolla. Now in the
collection of the Museo Nazionale della Scienza e della Tecnica,
Milan.]
[Illustration: Figure 25.--INTERIOR OF BERTOLLA'S WORKSHOP, showing
details of paneling and floor case with Bertolla manuscripts. (_Courtesy
of Museo Nazionale della Scienza e della Tecnica, Milan._)]
According to Pippa,[19] certain characteristics become apparent in a
study of the surviving clocks by Bertolla. The tall-case clocks are
narrow and range in height from 7-3/4 feet to 10-1/2 feet. The cases had
this excessive height in order to obtain the greatest fall for the month
and year movements which Bertolla constructed. For the weight assembly,
he substituted a drum wound with a key at the point of the driving wheel
in place of the customary pulley. The addition of an intermediate wheel
augmented the drop of the weight.
Bertolla's movements were solidly constructed from well-hammered brass
and iron. He favored the recoil anchor escapement in his clocks and the
Graham dead-beat anchor escapement with a seconds' pendulum. The
escapement was not always placed in the traditional location in the
upper center between the plates. Bertolla occasionally displaced the
pendulum to one side, to the lower part of the movement or placed it
entirely between two other small plates.[20]
He utilized every type of striking work, including the music-box
cylinder common in the clocks of the Black Forest and the rack and
snail. Bertolla most frequently employed the hour strike and _grand
sonnerie_. He often used a single hammer on two bells of different sound
with the rack and snail. An example of this type is the clock he
produced at the age of 80. To achieve the necessary axis of rotation for
the hammer, which is perpendicular to the plate when it strikes the
hours, it moves to an oblique position and displaces one of the two long
pins in an elongated opening.
Bertolla's dial plates were generally well executed, with a raised or
separate chapter ring applied to a brass or copper plate, such as a
copper-plate _repoussé_ and gilt with baroque motifs, or upon a smooth
brass plate with spandrels of _repoussé_ work usually of silver, in
relief and attached. The engraving of the chapter rings was excellent.
The hands were well executed in steel or perforated bronze, and
occasionally of _repoussé_ copper; gilt was applied to the hands made of
forged steel.
[Illustration: Figure 26.--DIAL PLATE of a brass lantern clock made by
Bertolla, found in his workshop after his death. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]
In the course of time, Bertolla's home workshop passed from one
generation to another within the family. Inevitably, it underwent many
modifications until the only original part of the building that remained
intact from Bertolla's time was his clockshop.
[Illustration: Figure 27.--MOVEMENT of a brass lantern clock made by
Bertolla. (_Courtesy of Museo Nazionale della Scienza e della Tecnica,
Milan._)]
Within the last few years, the workshop room was acquired complete with
contents from Bertolla's descendants, and installed in the Museo
Nazionale della Scienza e della Tecnica in Milan as an exhibit of a
typical 18th-century clockmaker's shop. The original workshop was
dismantled in Mocenigo di Rumo and completely rebuilt in the museum,
including the walls, ceiling and floor. The paneling and woodwork of the
walls and ceiling, which have been preserved intact, are hand-cut fir,
with columns, trim and moldings carved by hand. A small painting is
featured in the center of the coffered ceiling. The original shop
benches and chests of drawers are set around the reconstructed shop and
Bertolla's tools and equipment laid out as they had been originally.
Other clockmaker's tools and equipment in the museum's collection are
also displayed. Approximately 40 percent of the tools are the original
items from Bertolla's shop. Parts of clocks and works in progress are
on view on the benches as they were in Bertolla's time.[21] Also
preserved in the museum are sketches found in Bertolla's manuscripts,
some of which are reproduced on the following pages.
[Illustration: Figure 28.--DETAIL OF WALL of Bertolla's workshop, with
regulatory clock made by his nephew, Alessandro Bertolla of Venice. Note
wheel layouts, etc., scribed in the paneling. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 29.--TABLE CLOCK BY BERTOLLA in the collection of
Doctor Vittorio dal Lago of Bergamo. The dial indicates the days of the
week and of the month, the names of the months and lunar phases. The
clock strikes the hours and quarters and repeats. (_Courtesy of Sig.
Luigi Pippa of Milan._)]
The shop contains two completed clocks made by Bertolla. One is a
weight-driven lantern clock typical of the 18th century, Italian style
with brass dial, plates and posts, anchor escapement, and striking
work. The dial is engraved in the usual style of Bertolla's baroque
design, and the hands are of pierced bronze. Another clock associated
with Bertolla and found in the shop, was made by his nephew, Alessandro
Bertolla, who worked in Venice after his apprenticeship with his uncle
had been completed. This clock is a regulator with a seconds' pendulum
and sweep hand on an enameled dial. The original case has not survived.
[Illustration: Figure 30.--LAYOUT OF THE WHEELWORK of a clock made by
Bertolla for His Excellency Paulo Dona, inscribed "Design No. 1."
(_Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 31.--PENDULUM ARRANGEMENT SKETCH for an
unidentified clock found in Bertolla's workshop. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 32.--STRIKING CLOCK SKETCH found in Bertolla's
manuscripts. (_Courtesy of Museo Nazionale della Scienza e della
Tecnica, Milan._)]
[Illustration: Figure 33.--FIFTEEN-DAY STRIKING CLOCK SKETCH, inscribed
"Design No. 3," found in Bertolla's workshop. (_Courtesy of Museo
Nazionale della Scienza e della Tecnica, Milan._)]
[Illustration: Figure 34.--DIAL PLATE of a brass lantern clock made by
Bertolla at the age of 80. (_Courtesy of Museo Nazionale della Scienza e
della Tecnica, Milan._)]
[Illustration: Figure 35.--MOVEMENT of brass lantern clock produced by
Bertolla at the age of 80, showing details of movement and double bell.
(_Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan._)]
One of the most interesting of Bertolla's clocks, and probably the last
one which he produced, was found in his workshop. This timepiece
indicates the hours, minutes and quarters by means of a single hand or
index. The weight-driven clock strikes the hours and quarters on two
bells with a single hammer. The chapter ring, which is soldered to the
dial plate, is marked for the minutes on the outer rim and for the four
quarters inside it. Over the center of it, is a semicircular opening in
the dial plate through which is visible a revolving disk attached behind
the dial plate. This disk is marked with the hours and revolves from
right to left, the current hour being indicated by a projection from the
minute ring. The brass dial plate is engraved with simple floral
designs in the corners and around the broken arch. There is no
comparison between this crude and simple decoration and the extremely
fine quality of the engraving on the dial plate of the Borghesi clock,
for instance. In the center of the dial plate is engraved the following:
"Questo orologio l'ideai e lo feci nella mia avanzata età
d'anni 80. Bart^{o} Ant^{o} Bertolla"
(I designed and made this clock at my advanced age of 80 years.
Bartolomeo Antonio Bertolla.)
* * * * *
FOOTNOTES
[1] BORGHESI, _Novissimum Theorico-Practicum Astronomicum Authoma
Juxta Pariter Novissimum Mundi Systema..._, pp. 8-9.
[2] WENHAM, "Tall Case Clocks," p. 33.
[3] VON BERTELE, "The Development of Equation Clocks," parts 1
through 5.
[4] ENGELMANN, _Philipp Matthäus Hahn_; VISCHER, _Beschreibung
mechanischer Kunstwerke..._.
[5] LLOYD, _Some Outstanding Clocks Over Seven Hundred Years,
1250-1950_, pp. 116, 118, 120.
[6] SAN CAJETANO, _Praktische Anleitung für Künstler..._.
[7] FRANCH, _La Valle di Non_.
[8] BONOMI, _Naturalisti, Medici e Tecnici Trentini_, p. 16
[9] AMBROSI, _Scrittori ed Artisti Trentini_, pp. 132, 525.
[10] Ibid.
[11] PIPPA, "Antonio Bartolomeo Bertolla," pp. 22-23.
[12] Ibid., p. 22.
[13] Ibid., p. 23.
[14] The abbreviation in the inscription "pLan" is difficult to
interpret. According to Father F. X. Winters, S.J., it may
represent "sit planetis" or "sit planetarum." The use of an
abbreviation was necessary to prevent the addition of another
letter I or M, which would have disturbed the formation of the
chronogram desired. Literally, "sit planetis" means "May he be
eternal ruler _by_ [or _through_] favor of the planets," while
"sit planetarum" is to be translated "May he be eternal ruler
_of_ the planets." Father Winters considered both versions
somewhat overexaggerated and proposed that the best translation
might be "Long Live Francis I, Emperor."
[15] The word "Tempe" refers to the Vale of Tempe, in Thessaly,
through which the Peneus River flows. It is between Mounts
Olympus and Ossa, and is situated between the town of Larissa
and the sea. In mythology, it is told that these mounts were
originally joined and Hercules separated them to allow the river
to pass between them. The word "Tempe" is also used to mean any
pleasant place. Thus, the inscription "Tempe indesinenter
clausa, Scaturigo signata" is literally translated "Tempe always
closed, A fount of water sealed up" or, freely translated, as "A
garden enclosed, a fountain sealed up."
[16] "Phoebi" or Phoebus, called Apollo, the sun god; Phoebes or
Diana, the moon goddess, sister of Apollo.
[17] PIPPA, op. cit. (footnote 11), pp. 23-25.
[18] PERINI, _Statistica del Trentino, Biblioteca Communale del
Trentino_, vol. 2, p. 57 (cons. 6, carta 9); TOVAZZI,
_Biblioteca Tirolese_, pp. 406-407.
[19] PIPPA, op. cit. (footnote 11), pp. 24-25.
[20] PIAMONTE, _La Nauna Descritta al Viaggiattore_.
[21] ESPOSTI, "La Sala 'Innocente Binda' al Museo della Scienza e
della Tecnica di Milano," pp. 18-21.
Appendix
SYNOPSIS OF THE COMPLETE MECHANICAL WORKS OF THE FIRST CLOCK
[Translated from the section entitled "Synopsis Totius Operis
Mechanici" in Francesco Borghesi's first book _Novissima Ac
Perpetua Astronomica Ephemeris Authomatica
Theorico-Practica..._.]
I
Of three movable indices, the farthest from the center of the dial is
fitted with an index on either side and marked with four segments of a
circle. Immediately below are five numbers, divided into the days of
setting the measure of the mean-synodic age of the moon, and into signs,
degrees of the signs, and of the distance of the moon from the sun.
These, in each revolution, revolve once around the solar disk
superimposed on the mean synodic-lunar disk, and also around the lunar
disk. The upper indices, meanwhile, in the two external greatest orbits,
measure the time continuously, in the accustomed manner of the
Germans--the middle index measuring by hours and the uppermost by the
first minutes [of hours].
II
Inside these three circles, perpendicular above their center, is a small
index of the seconds of minutes. At each first minute of time, being the
fastest of all, it describes the smallest orbit. Next to this are two
other slightly larger circles divided into 30 degrees, one [rotating?]
from the right, the other from the left. These two indices are arranged
in such a fashion that the one rotating from the observer's left
completes its period 12 times during one, mean, solar-astronomical year.
The one [rotating] from the right likewise completes its cycle 12 times
during the period of one mean-synodic moon. In between these, there is
placed another small sphere, divided into 40 arbitrary parts, whose dial
does not move automatically, but is moved by hand for speeding up or
slowing down the course of the time, or of the perpendicular.
III
Diagonally from the sides of the center of the three larger indices, six
other indices revolve: three on the left from one center, and three on
the right from another. The uppermost of the three which are on the
right of the observer [and which are] decorated with a small disk of the
sun, runs its cycle once during a mean solar-astronomical year. The
second measures the distance of the sun from its apogee. The third
revolves 12 times, with each lunar revolution from one node to the same
[repeated] node. Under the point of the uppermost index, first lie the
months of the year which are inscribed, and the days of each month, but
having only 28 days assigned to February; then the signs of the zodiac,
and their several degrees. The circle corresponding to the middle index,
extending through the first semicircle from apogee to the lower perigee
and returning through the second semicircle to the upper locations of
apogee, shows the true equation or eccentricity of the sun, joined with
the little equation of the moon in syzygy. [These equations are]
measu
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