They set out early one morning, his father bent low beneath a knapsack containing the Head of Phalaris, which he insisted upon carrying himself. It was snowing. The Sun rose dimly in front of them, behind a tangle of tree limbs lined with white. As they passed the midpoint of the Old Stone Bridge, where centuries before the martyr John of Nepomuk had been flung into the Vltava on the orders of Wenceslaus, King of Bohemia, and which now was presided over by a statue of Emperor Maximilian on his steed, the winds, which were already crazed, grew positively demented, howling, as the astronomer recalled, over the frozen surface of the river below. Somewhere high above, hidden in swirls of snow, the big brass contraption groaned. The weather, in fact, had been worsening for weeks, the Sun had slipped behind a cloud the moment the Emperor had signaled the start of his astronomical convocation with the ringing of the bells of the Cathedral of Saint Vitus and it had not reappeared since, but only now, at the instant, as it happens, that the astronomer and his father reached the bottom of the long stone stairway that wound its way precipitously up to the Castle, did the storm intensify into a blizzard. It was well-known at that time that meteorological conditions in Prague were causally connected to conditions in the Emperor’s mind, a phenomenon that certain churchmen as well as the vulgar attributed to the action of demons flitting in and out of the Emperor’s head, which evidently they could, on this theory, enter at will—“anything of course can be explained by recourse to a head-entering demon!”—although the astronomer, employing a precursor of Torricelli’s barometer, had been able to establish that the Emperor’s head actually influenced the city of Prague through the medium of the air. So what they beheld in the skies now they would presumably behold in the Emperor’s head, if indeed they reached the Emperor at all. That boded well for the astronomer, since it meant the virtuosi invited into the Castle along with their archaic contraptions had failed to put the imperial mind at ease and had even whipped it further into a fervor, but it boded ill, he thought, for his father, and his father’s trinket, and did little to quell his appalling suspicion that he was deliberately escorting the old man to his doom. And as his father began dragging himself up those steep stairs, his huffing and puffing audible above the fantastic clatter of the gale, one hand outstretched for balance and the other pressed to his cap, which threatened to fly off at any moment, its feather flapping spasmodically in the wind, the astronomer felt quite certain that his father’s heart was about to give out, or that his father would slip on the ice and crack his skull on the stone, and even had a vision of the mechanical head sliding out of the sack and obliterating itself and its fragile inner workings as it whacked every single step all the way down before vanishing with a realistic gurgle in the Vltava. But that did not happen. In fact, as they approached the Castle, his father seemed, somehow, to gain strength. He caught his breath, straightened his shoulders, put down firm footfalls on the icy stone, while behind him his son began to huff and puff, to curl inward against the driving snow, to slip and stumble and once very nearly stagger backward into the abyss. By the time they reached the top of the stairs, where a snowy halberdier manning a grand gate flanked by two statues of Emperor Maximilian thumped the ground with the butt of his weapon (thus bursting forth from the snow blanketing him) and ordered the two to go no farther, he saw that his father’s beard, underneath the ice that now encased it, had even recovered some of its former coloring: the white was flecked with gray. This was no mere trick of memory. “He really was extracting some sort of life force from his increasing proximity to the center of the Empire and directing it toward his beard.” The astronomer realized that he did not and could not comprehend the appeal to his father of proximity to power until that moment, as he watched it affect the coloration of his father’s beard. “We were very different creatures, I realized, if I could not even sense this life force emanating from the center of the Empire, whereas he not only sensed it but somehow tapped into it to effect the rejuvenation of his beard.” It was not merely a matter of different tastes, of valuing things differently, but of different sensory apparatuses, of sensing things differently. “Seeing his beard get grayer, first a little grayer, and then a lot grayer, I naturally felt a surge of sympathy for my father, whom I ought to have regarded not as a man with different principles but as an animal with different senses, less a shameless courtier than a bat,” he told Leibniz. (One is reminded of Bertrand Russell’s contention that the contradictions of Leibniz’s philosophy stem from his hunger for “the smiles of princes.”) With newfound vigor the astronomer’s father righted his cap and in a bold voice informed the young halberdier that he was the former Imperial Sculptor to the deceased Emperor Maximilian, King of Hungary, King of Bohemia, and King of the Romans, and he, who had designed the famous Maximilian Fountains of Vienna, had come for an audience with Emperor Rudolf. And he said it in such a way that the halberdier not only swung open the gate forthwith but even saluted them as they passed. At another gate a hundred yards closer to the Castle this performance repeated itself precisely, and soon a retinue of guards, functionaries, and attendants had materialized around the astronomer and his father and conducted the two of them toward the bowels of the Castle complex, blowing through gates, doors, and checkpoints, eliciting a blur of bows, salutes, and clicked heels, while his father’s barely suppressed grin beamed forth from within a beard that was by now “the formidable and frightening black of my early childhood.”