He told the story of his introduction to the idea of the occhialino or perspicillum with some circumspection:
About ten months ago, a rumor came to our ears that a spyglass had been made by a certain Dutchman, by means of which visible objects, although far removed from the eye of the observer, were distinctly seen, as though nearby. This caused me to apply myself totally to investigating the principles and figuring out the means by which I might arrive at the invention of a similar instrument, and I achieved that result shortly afterward on the basis of the science of refraction.
A few strategic opacities there, but that was all right. He arranged with a Venetian printer, Tomaso Baglioni, for an edition of 550 copies. The first page, an illustrated frontispiece, said in Latin:
THE STARRY MESSENGER
Revealing great, unusual, and remarkable spectacles,
opening these to the consideration of every man,
and especially of philosophers and astronomers;
AS OBSERVED BY GALILEO GALILEI
Gentleman of Florence
Professor of Mathematics in the University of Padua,
WITH THE AID OF A PERSPICILLUM
lately invented by him,
In the surface of the moon,
in innumerable Fixed Stars,
in Nebulae, and above all
in FOUR PLANETS
swiftly revolving about Jupiter at differing distances and periods,
and known to no one before the Author recently perceived them
and decided that they should be named
THE MEDICEAN STARS
Venice 1610
The first four pages following this great proem of a title page were filled by a dedication to Cosimo Medici that was exceptionally florid even for Galileo. Jupiter had been in the ascendant at Cosimo’s birth, it pointed out; pouring out with all his splendor and grandeur into the most pure air, so that with its first breath Your tender little body and Your soul, already decorated by God with noble ornaments, could drink in this universal power…. Your incredible clemency and kindness … Most Serene Cosimo, Great Hero … when you have surpassed Your peers You will still contend with Yourself, which self and greatness You are daily surpassing, Most Merciful Prince … from Your Highness’s most loyal servant, Galileo Galilei.
The book was published in March of 1610. The first printing sold out within the month. Copies circulated throughout Europe. Indeed its fame was worldwide. Within five years word came that it was being discussed at the court of the Chinese emperor.
Despite this literary and scientific success, the Galilean household was still running at a loss, with Galileo’s time also massively overcommit-ted. He wrote to his friend Sagredo, I’m always at the service of this or that person. I have to eat up many hours of the day—often the best ones—in the service of others. I need a prince.
On May 7, 1610, he wrote a follow-up inquiry to Vinta. He did not beat around the bush, but made it an explicit letter of application, a real piece of rhetoric. He requested a salary of a thousand florins a year, and sufficient free time to bring to completion certain works he had in progress. Glancing up at the dusty workbooks on the shelf to make sure he forgot nothing, he made a list of what he hoped to publish if he were given the time:
Two books on the system and constitution of the universe, an overarching conception full of philosophy, astronomy, and geometry; three books on local motion, an entirely new science, as no one else ancient or modern has discovered the many amazing properties that I demonstrate to exist in natural and forced motions, which is why I may call this a new science discovered by me from its first principles; three books on mechanics, two pertaining to principles and foundations, one on its problems—and though others have written on this same material, what has been written to date is not one-quarter of what I will write, either in quantity or otherwise. I have also various little works on physical subjects, such as On Sound and Voice, On Vision and Colors, On the Tides, On the Composition of the Continuum, On the Motion of Animals, and still more. I will also write on military science, giving not only a model of what a soldier ought to be, but also mathematical treatises on fortification, the movement of troops, sieges, surveying, estimating distances and artillery power, and a fuller description of my military compass,
—which is in fact my greatest invention, he did not add—a single device that allows one to make all of the military calculations I have already mentioned plus also the division of lines, the solution of the Rule of Three, the equalization of money, the calculation of interest, proportional reduction of figures and solids, extraction of square and cube roots, identification of the mean proportionals, transformation of parallelepipeds into cubes, determination of proportional weights of metals and other substances, description of polygons and division of circumferences into equal parts, squaring of the circle or any other regular figures, taking the batter of scarps on walls—in short it was an omnicalculator, able to make any computation you could want, despite which hardly anyone has noticed its existence, and even fewer bought one, so stupid was the common run of humanity!
But that was not germane, even though the reaction to his compass still galled him and was one of the events driving this whole move back to Florence. It wasn’t a good subject to bring up, so he only moved to his conclusion:
Finally, as to the title and the scope of my duties, I wish in addition to the name of Mathematician that His Highness adjoin that of Philosopher. Whether I can and should have this title I shall be able to show Their Highnesses whenever it is their pleasure to give me a chance to deal with this in their presence with the most esteemed men of that profession,
—such as they are, being for the most part grossly overpaid Peripatetic idiots!
Reading over the final flourishes, and looking at the red leather of their best spyglass yet, embossed in gold with typical Florentine and Medici figures, it seemed to him that the opportunities being offered to any potential patron were too great to decline. What an application! Even the transport case into which everything was loaded for the Florentine courier was beautiful. Who could say no to such a thing?
And, in fact, on May 24, 1610, a reply from Vinta came to the house behind the church of Santa Giustina, the house on Via Vignali where they had all lived and worked together for eighteen years. Grand Duke Cosimo, Vinta wrote, accepts your services.
Galileo wrote to accept the acceptance on May 28. On June 5, Vinta wrote back, confirming that his title would be “Chief Mathematician of the University of Pisa and Philosopher to the Grand Duke.”
Galileo wrote back in turn, asking that his title be revised to “Mathematician and Philosopher to the Grand Duke.”