Mazzoleni left and he drifted off. When he woke again it was the cool of early morning, sunlight hitting the top of the garden wall. The morning glory was a well-named flower. The blue of the sky had pale sheets of red and white pulsing inside it.

The stranger’s old servant stood there before him, holding out a cup of coffee.

Galileo jerked back. On his face one could see the fear. “What are you doing here?” He began to remember the stranger’s appearance the night before, but little beyond that. There had been a big heavy spyglass that he had sat on his stool to look through…. “I thought you were part of the dream!”

“I brought you some coffee,” the ancient one said, looking down and to the side, as if to efface himself. “I heard you had a long night.”

“But who are you?”

The old man shoved the cup even closer to Galileo’s face. “I serve people.”

“You serve that man from Kepler! You came to me last night!”

The old one glanced up at him, lifted the cup again.

Galileo took it, slurped down hot coffee. “What happened?”

“I can’t say. You were struck by a syncope for an hour or two in the night.”

“But only after I looked through your master’s spyglass?”

“I can’t say.”

Galileo regarded him. “And your master, where is he?”

“I don’t know. He’s gone.”

“Will he return?”

“I can’t say. I think he will.”

“And you? Why are you here?”

“I can serve you. Your housekeeper will hire me, if you tell her to.”

Galileo observed him closely, thinking it over. Something strange had happened the night before, he knew that for sure. Possibly this old geezer could help him remember—or help him in whatever might come of it. Already it began to seem as if the ancient one had always been there.

“All right. I’ll tell her. What’s your name?”

“Cartophilus.”

“Lover of maps?”

“Yes.”

“And do you love maps?”

“No. Nor was I ever a shoemaker.”

Galileo frowned, then waved him away. “I’ll speak to her.”

And so I came into the service of Galileo, intending (as always, and always with the same failure) to efface myself as much as possible.

In the days that followed, Galileo slept in short snatches at dawn and after dinner, and every night stayed up to look through his spyglass at Jupiter and the little stars circling it, his curiosity now tweaked by an odd feeling in the pit of his stomach. He marked the four moons’ positions each night using the notation I, II, III, and IV, with I being the closest to Jupiter in the orbits he was now untangling, and IV the farthest away. Tracking and timing their movements gave him an increasingly confident sense of how long each took to circle Jupiter. All the expected signs of circular motion seen edge-on had manifested themselves. It was getting clearer what was going on up there.

Obviously he needed to publish these discoveries, to establish his precedence as discoverer. By now Mazzoleni and the artisans had made about a hundred spyglasses, but only ten of them were capable of seeing the new little planets; they became visible only through occhialini with magnifications of thirty times, and sometimes twenty-five when the grinding was lucky. (What else had been twenty-five or thirty times larger?) The difficulties in making a device this powerful reassured him; it was unlikely someone else would see the Jovian stars and publish the news before him. Still, it was best not to be slow about it. There was no time to lose.

“I’m going to make those bastard Venetians really regret their offer!” he declared happily. He was still furious at the senators for questioning his honesty in representing the spyglass as his invention. He took pride in his honesty, a virtue he wielded so vigorously as to make it a fault. He also hated their measly raise, which was not even to start until the new year, and now was looking more and more inadequate. And really, through all the years in Padua—eighteen now—he had kept in the back of his mind the possibility of a return to Florence.

Ignoring the little awkwardness that had developed the year before with Belisario Vinta, he wrote another florid note accompanying the finest spyglass he had, explaining that he was giving it to his most beloved student ever, now the grandissimo Grand Duke Cosimo. He described his new Jovian discoveries, and asked if it would be permissible to name his newly discovered little Jovian stars after Cosimo. And if so, if the grand duke would prefer him to name them the Cosmian Stars, which would merge Cosimo and Cosmic; or perhaps to apply to the four stars the names of Cosimo and his three brothers; or if they should together be named the Medicean Stars.

Vinta wrote back thanking him for the spyglass and informing him that the grand duke preferred the name Medicean Stars, as best honoring the family and the city it ruled.

“He accepted the dedication!” Galileo shouted to the household. This was a stupendous coup. Galileo hooted triumphantly as he charged around, rousing everyone and ordering that a fiasco of wine be opened to celebrate. He tossed a ceramic platter high in the air and enjoyed its shattering on the terrace, and the way it made the boys jump.

The best way to announce this dedication to the world was to insert it into the book he was finishing about all the discoveries he had made. He pressed hard to finish; the combination of work by both day and night left him irritable, but it had to be done. At night, working by himself, he felt enormously enlarged by all that lay ahead. Sometimes he had to take a break and walk around in the garden to deal with the thoughts crowding his head, the various great futures looming ahead of him like visions. It was only during the days when he flagged, slept at odd hours, snarled at the household and all that it represented. Scribbled at great speed on his pages.

He wrote the book in Latin so that it would be immediately comprehensible across all the courts and universities of Europe. In it, he described his astronomical findings in more or less chronological order, making it into a narrative of his discoveries. The longest and best passages were on the moon, which he also augmented with good etchings made from his drawings. The sections on the stars and the four moons of Jupiter were shorter, and mostly just announced his discoveries, which were startling enough not to need embellishment.

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,