Appendix 



SYNOPSIS OF THE COMPLETE MECHANICAL WORKS 

 OF THE FIRST CLOCK 



[Translated from the section entitled "Synopsis 

 fotius I >peris Mechanici" in Francesco Borghesi's 

 first book Novissima .1- Perpetua Astronomica I : 



Authomatica Theorho-Practica ... .1 



I 



< »i three movable indices, the farthest from the 

 center of the dial is fitted with an index on cither side 

 and marked with four segments of a circle. Im- 

 mediately below .ire five numbers, divided into the 

 days of setting the measure of the mean-synodic age 

 of the moon, and into signs, degrees of the sign*., 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 hums 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 thai 

 the one rotating from the observer's left completes 

 its period 12 times during one. mean, solar-astronomi- 

 cal year. The one [rotating] from the right likewise 



i ompli tes its cycle 12 times during the pet iod ol one 

 mean-synodic moon. In between these, there is 

 placed another small sphere, divided into 40 arbitrary 

 parts, whose dial does not move automatically, bul is 

 moved by hand foi speeding up or slowing down the 

 course oi the time, or of the perpendicular. 



Ill 



Diagonally from the sides of the center of the three 



indices, six Other indices revolve: three on the 

 l'lt 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 ch^k of the sun. runs its i vc le on< e during 

 .i mean solar-astronomical year. The second meas- 

 ures 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. I ndei 

 the point of the uppermost index. Insi he the months 

 ol the year which are inscribed, and the d.ivs ol 

 month, but having only -'•'> dav - assigned to February; 

 then the signs of the zodiac, and their several di 

 The circle corresponding to the middle index, extend- 

 ing through the first semicircle from apogee to the 



lower perigee and returning through the- set 



i in le to the upper locations of apogee, shows thi 



equation Or eccentricity of the sun. joined with the 



little equation of the moon in syzygy. [These equa- 

 tions are] measured by geometric-astronomic propor- 



PAPER 35: IIIF. BORGHISI ASTRONOMIC \I clot.K 



71 



