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 ill.u.s.trations. The frontispiece is surmounted at its center by the crowned double eagle of the House of Hapsburg, indicating the ident.i.ty 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 G.o.d 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.
[Ill.u.s.tration: Figure 10.--DIAGRAM OF the dial plate.]
[Ill.u.s.tration: 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 lat.i.tude 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 _r.e.t.a.r.dit_ (it r.e.t.a.r.ds) 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 n.o.blemen apparently examining and discussing an orb upon a table, the significance of which is not clear.
[Ill.u.s.tration: 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.
[Ill.u.s.tration: 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 G.o.d, and to the Mother of G.o.d).
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 a.s.sembled 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 G.o.d 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).
[Ill.u.s.tration: Figure 14.--THE BOTTOM RIGHT CORNER of the dial plate, showing two n.o.blemen 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, _a.s.sidvo p.r.o.ni donant di cvncta labori_. (The favorable G.o.ds willingly grant all things to the a.s.siduous 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 n.o.blemen, _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 cla.s.sical prototypes have been identified.
[Ill.u.s.tration: Figure 15.--THE BOTTOM LEFT CORNER of the dial plate, showing the engraving of Atlas, with the inscription "a.s.sidvo p.r.o.ni donant di cvncta labori." (The favorable G.o.ds willingly grant all things to the a.s.siduous laborer.)]
CENTER DIAL INSCRIPTIONS
[Ill.u.s.tration: Figure 16.--DETAIL OF FRONTISPIECE of the Borghesi clock, showing the apertures for calendar indicators and the details of the engraving.]
In addition to the inscriptions previously noted on the outer dial plate, there are three major inscriptions in the central dial. The outermost states _Circulus horarius Soli_, _Lunae_, _Fixis_, _Nodis_, _Aestuique marino communis_ (the hour circle, common to the sun, the moon, the fixed stars, the nodes and to the sea tide). This inscription is divided into four parts by the insertion of four divisions for the day into canonical hours: [_Horae_] _Nocturnae_ (night hours); _Matutinae_ (morning hours); _Diurnae_ (daytime hours) and _Vespertinae_ (evening hours).
The next section of the central dial is inscribed _Intumescite--Detumescite_ (rise and fall of the tides) repeated at intervals of approximately every six hours. Within the next section is the following inscription, inscribed continuously around the ring:
Lege fluunt, refluunt, dormitant hac maris undae: Ad Phoebi et Phoebes concordia iussa moventur Aequora; discordi iussu suspensa quiesc.u.n.t.
Translated, this is:
By this law the sea waves ebb and flow and lie dormant: When Phoebus and Diana agree in their commands, the waters are moved; when they disagree, the waters lie silent.[16]