a frown. “The light is much too diffuse, shining in all directions.”
“Well, you can’t capture the light like a herd of wild horses,” said Valentin mockingly. “As soon as it finds a way out, it goes wherever it wants to. If only I’d never seen those drawings. What a waste of time.” He was about to shove the apparatus off the table when Johann held him back.
“We’re not giving up yet,” he said sternly. “Maybe we’ll find a way to focus the light better.”
“Sure, sure,” jeered Valentin. “Where the great Giovanni Fontana and Leonardo da Vinci failed, the oh-so-famous Doctor Faustus will succeed.”
“Who knows, perhaps they’ll call me that one day,” muttered Johann. A vague idea was buzzing through his mind, but every time he tried to grasp it, it slipped away.
Johann continued to be wary of Hans Altmayer. He got the impression the fellow was hatching something. Whenever they passed each other, Altmayer grinned, placed one finger at his beret, and hinted at a bow.
“Look at that—Herr Faustus, the doctors’ pet,” he’d say. “Just you wait. The higher you climb, the farther you fall.”
“And if you never climb, you remain forever in the stinking gutter,” retorted Johann as he walked away.
Johann experienced his personal eureka moment during a lecture by Rector Gallus about Archimedes’s principle.
Winter had moved into Heidelberg by now. The snow piled up in the lanes and made it difficult to get around. It was so cold in the lecture halls that the students shivered in their coats and hats. Johann finally understood why the berets had padded earflaps. The small stoves weren’t nearly enough to heat the large rooms. Saint Mary’s Chapel was the worst, the wind howling through its drafty windows. White clouds came from the mouths of the doctors as they spoke, and thin sheets of ice spread across benches and desks.
It was a bitter cold morning in January, but at least the sun shone weakly through the windows. As usual, the rector wore his strange-looking eye glasses, but the students were accustomed to the sight by now. He took them off only occasionally, when he gazed into the distance. Gallus was talking about the buoyancy of objects when a ray of light fell through the window and directly upon his glasses, which were lying on the lectern in front of him. Johann noticed with amazement how the weak light was bundled in the glasses and appeared on the opposite wall as a bright speck. The speck was brighter than the pale sunlight streaming through the window.
Much brighter.
“Archimedes posits that the upward buoyancy . . . ,” Jodocus Gallus was saying when Johann sprang to his feet and rushed out of the hall. Irritated, the rector broke off. “Let us hope it’s just the call of nature urging our dear Faustus to leave us thus.”
“Or the infallible Herr Faustus already knows everything about Archimedes and is off to invent his own floating object,” jeered Altmayer, but no one laughed.
Johann ran over to the low, snow-covered buildings of the school of arts, where Valentin was attending one of Partschneider’s classes. Out of breath, he sat down next to Valentin in the last row and leaned over to him.
“I know it now,” he whispered.
Valentin turned his head in surprise. “You know what now?”
“I know how we can capture and focus the light inside the laterna magica. We use lenses made of glass! Lenses like they use for eye glasses. Rector Gallus’s glasses just gave me the idea.”
Johann’s voice grew louder, and Magister Partschneider interrupted his lecture irritably. “If the young sirs believe they already know everything, they are welcome to leave the room.”
Johann tugged at Valentin’s sleeve until his friend gave in and followed him outside.
“Are you crazy?” spat Valentin. “Partschneider will never forgive us!”
“Oh, he’ll get over it,” replied Johann, grinning. “Much more importantly, we can now complete the laterna magica.”
He quickly explained to Valentin what he’d found out. His friend seemed skeptical at first, but then he nodded. “Hmm. I think you’re right—it might work with lenses. They bundle the light—I know what you mean about Gallus’s glasses. And if we placed several lenses in front of each other—”
“The light would become stronger and the image clearer,” added Johann.
He then suddenly remembered the strange tube he’d seen up on the tower by the Alps a long time ago, back when he was still with Tonio. He guessed the tube had also contained several lenses, one behind the other, enabling a person to see farther.