He wondered where Tonio had gotten the tube. Johann had never seen anything like it again, not even here at the university.
“I admit, it’s a brilliant idea, but unfortunately, we have no lenses nor the money to buy some,” said Valentin, interrupting Johann’s pondering. “Eye glasses are expensive—perhaps more expensive than mirrors.”
“I’ll get the lenses,” said Johann curtly. “You just worry about fitting them.”
Johann had already decided to steal Rector Gallus’s glasses—in the name of science. At some distant point in the future he would tell Gallus, and Johann felt certain the man would understand. Besides, he was the rector of Heidelberg University—surely he could purchase another pair of glasses. And in a few years’ time, when Johann had become a highly esteemed doctor himself, they’d laugh about the old story.
Valentin eyed Johann suspiciously. “I don’t like you much at the moment, Johann. If you go on like this—”
“Do you want the laterna to work or not?” snarled Johann, cutting him off.
Valentin gave a shrug. “All right, fine. I hope we can talk normally again once we’re done with the laterna. Like friends usually talk.”
The opportunity for the theft arose a few days later. During a conversation with Rector Gallus following a lecture, Johann saw that the glasses were once again lying on the lectern. It was almost too easy. Johann placed his books on top of them and picked them up together. The rector didn’t notice anything.
Johann’s heart beat wildly as he walked out of the chapel, but neither Gallus’s cutting voice nor any hurried footsteps rang out behind him. In a shady niche between two buildings, he carefully broke the glass lenses from their frames and buried the frames in a pile of snow. A twinge of conscience overcame him; the rector had done so much for him. But then he told himself again that he was acting solely in the name of science, and that Gallus would thank him one day.
When Johann gave the lenses to Valentin, he turned them thoughtfully in his hands. “I’d be glad if they weren’t what I think they are,” he remarked glumly.
“I have my resources,” said Johann. “Best you don’t ask.”
They formed a tube from a piece of tin and experimented with different distances. Conrad Celtis had also given Johann a metal concave mirror so that the light from the oil lamp was much better bundled. When they felt certain that they were on the right track, they installed the tube into their apparatus, which had grown in size.
It was an evening in February when Valentin finally lit the oil lamp of the laterna magica once more and carefully inserted one of the glass plates into the slot. It was the picture of the cat with the arched back—his favorite. Then he opened the flap at the front.
The result was so overwhelming that they cried out almost simultaneously and took a step back.
From the opposite wall of the shed, a monster stared at them that was as large as a calf and as menacing as a lion on the prowl. The cat’s arched back and hissing mouth seemed as lifelike as if it had just walked into the room. The picture was slightly unfocused at the edges and it flickered a little, which added to the ghostly effect. Johann felt as though he had just entered a strange new world.
“That . . . that’s incredible!” he gasped.
“It’s working!” Valentin grinned from ear to ear. “Do you know what that means? The two of us—two students—have just created an apparatus that not even the great Leonardo da Vinci managed to build. When we show Rector Gallus what—”
“We can’t show Rector Gallus,” objected Johann.
Valentin’s expression darkened. “So it’s true.”
“It’s not just the eye glasses,” explained Johann. “We told Gallus we were building a camera obscura. If we turn up with this apparatus instead, he’ll know we’ve been lying to him the whole time.”
Johann tried to sound reasonable, but he really was afraid the rector would become angry and accuse him of theft. First and foremost on his mind, however, was a different motivation: the laterna magica was their invention, and he didn’t want to share it with other scholars. It was their treasure.
And there was another hazy idea taking shape in his head about how he could put the laterna to good use.
“They’ll charge us with sorcery,” he said, gesturing at the cat staring at them from the wall. “Don’t you see how uncanny it looks? Partschneider and some of the other magisters