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);