“_Di Firenze li 11 di Decembre 1610._—Sto con desiderio, attendendo la risposta a due mie scritte ultimamente per sentire quello, che averà detto il Sig. Keplero della stravaganza di Saturno. Intanto mando [a Vostra Signoria Illustrissima e Reverendissima] la cifra di un altro particolare osservato da me nuovamente, il quale si tira dietro la decisione di grandissime controversie in Astronomia, ed in particolare contiene in se un gagliardo argomento per la constitutione [Pitagorica e Copernicana] dell’Universo; e a suo tempo pubblicherò la deciferazione ed altri particolari. Spero che averò trovato il metodo per definire i periodi dei quattro Pianeti Medicei, stimati con gran ragione quasi inesplicabili dal Sig. Keplero, al quale piacerà, ec. “Le lettere trasposte sono queste: “Haec immatura a me jam frustra leguntur, o.y.” Which may be translated thus:— “I am anxiously looking for an answer to my last two letters, that I may learn what Kepler says about the marvels of Saturn’s orb. In the meantime I send him a riddle concerning a certain new and splendid observation which tends to decide great controversies in astronomy; and especially contains a fine argument in favour of the Pythagorean and Copernican system of the universe. At the proper time I will publish the solution of the riddle, and some other particulars. I hope that I have found a method of determining the periodic times of the four Medicean planets, which Kepler, not without very good reason, thought inexplicable, etc. “The letters turned into an anagram, are these: “Haec immatura a me jam frustra leguntur, o.y.” So far Galileo. But if, reader, this letter has filled you with a desire to know the meaning contained in those letters, then you must read another letter of Galileo which follows. [Illustration: Fig. 1. _E the Earth (centre of universe). S the Sun. C centre of eccentric. D centre of planet’s epicycle. VV' stationary points. s v v' projections of SVV' on the ecliptic of which E is the centre._] [Illustration: Fig. 2. _S the Sun, centre of solar system. v e positions of planet and Earth at conjunction. VV' stationary points of planet. EE' corresponding positions of the Earth._]