“On the contrary, Doctor! When I bid you adieu I shall go straight back to the Hague to resume my studies with Mr. Huygens. ’Twill be a year or more before I address the Royal Society on any matter. Wren’s library remains half-built for want of funds.”
“Very well, then,” Leibniz muttered, and led Fatio through a temporary door of rough planks and into the stable. It was unheated, but it got their faces out of the wind, and their feet out of the snow. The foundation and ground-floor walls were made of large blocks of undressed stone. Everything above those was built of timbers. So far, the temporary scaffolding was more substantial than the structure itself, which was only sketched in with a few posts and beams. Fatio was baffled, and soon turned his huge eyes downwards to the several tables arrayed in the center of the main floor.
“One day we shall haul out these rude workbenches and replace them with polished desks where scholars will go to their work, illuminated by sky-light from a high fair cupola above,” Leibniz said, craning his head back so that his wig shifted, and thrusting his index finger up through the cloud of vapor that had veiled his words.
“The cupola is a fine innovation, Doctor. Getting adequate light is ever a problem in libraries. Sometimes I am tempted to burn one page to shed light on the next.”
“It is but one instance of the principle.”
“Which principle?”
“I told you I am trying to build a tool, an engine.” Leibniz sighed out a vast cloud of steam.
The tabletops supported divers forms of industry. Each was a gelid still-life unto itself. About half were given over to the library-building project (drawings weighed down with stones and wood-scraps, ragged quills projecting from frozen ink-wells, half-completed ledgers, clamped timbers surrounded by knee-high piles of wood-shavings) and half to whatever the Doctor was interested in at the moment. Fatio drew up short in front of a table strewn with what appeared to be stones; but as he did not fail to note, each stone was impressed with the skeleton of a leaf, insect, fish, or beast—some of them utterly unfamiliar.
“What—”
“I have laid off of Dynamics for the time being and am trying to finish another book Proto-gaea, whose subject matter you may know from the title. But let us refrain from digressions,” said Leibniz, shuffling carefully across the cluttered room. He paused to regard a colossal piece of furniture. “You see I am not the first to contemplate the making of a knowledge engine.”
Fatio closed his eyes, which was the only way to pry his attention from the outlandish skeletons, and stepped back, then maneuvered over to join Leibniz.
“Behold, the Bücherrad!”* Leibniz said.
Viewed end-on, the Bücherrad was hexagonal, and nearly as tall as Fatio. When he worked his way round to the front, he saw that it consisted mostly of six massive shelves, each one a couple of fathoms long, bridging the interval between hexagonal end-caps that were mounted on axles so that the whole apparatus could be revolved. But each of the six shelves was free to revolve on an axis of its own. As the Bücherrad spun, each of those shelves counter-rotated in such a way that it maintained a fixed angle with respect to the floor, and did not spill its load of books.
Going round to the other end, Fatio was able to see how it worked: a system of planetary gears, carven from hard wood, spun about the central axle-tree like Ptolemaic epicycles.
Then Fatio turned his attention to the books themselves: curious folio volumes, hand-written, all in the same hand, all in Latin.
“These were written out personally by one Duke August, a forerunner of that lot you just met. He lived to a great age and died some twenty-five years ago. It was he who assembled most of this collection,” Leibniz explained.
Fatio bent slightly at the waist to read one of the pages. It consisted of a series of paragraphs each preceded by a title and a long Roman numeral. “It is a description of a book,” he concluded.
“The process of abstraction continues,” Leibniz said. “Duke August could not keep the contents of his library in his memory, so he wrote out catalogs. And when there were too many catalogs for him to use them conveniently, he had woodwrights make Bücherrads—engines to facilitate the use and maintenance of the catalogs.”
“It is very ingenious.”
“Yes—and it is threescore years old,” Leibniz returned. “If you do the arithmetick, as I have, you may easily demonstrate that to hold all the catalogs needed to list all the world’s books would require so many Bücherrads that we would need some Bücherradrads to spin them around, and a Bücherradrad-rad to hold all of them—”
“German is a convenient language that way,” Fatio said diplomatically.
“And so on with no end in sight! There are not enough woodwrights to carve all of the gears. New sorts of knowledge-engines will be demanded.”
“I confess you have lost me, Doctor.”