Leeuwenhoek’s Lens

And over and above all, most men are not curious to know: nay, some even make no bones about saying: What does it matter whether we know this or not?

—Letter from Leeuwenhoek to Leibnitz, 28 September 1725

From the deck of the trekschuit, I watched Rotterdam and its forest of ships’ masts shrink and recede, and with the sight of them went, blessedly, the smell of herring and the scream of gulls. Bred to the Black Lands and acclimatized to the solidity of Birmingham, I had little love for the mutable sea and the teeming bustle of its ports and was well pleased to have exchanged waves and briny air for the gentle roll of a canal boat towed through the countryside.

The plodding horse team on the bank dragged us through bucolic scenery. The flat plains and the geometric precision of fields and orchards heavy with the bloom of spring were a vision of Eden—or at least as Eden would’ve appeared had God been deeply invested in the export of agricultural products. One can’t fault the Dutch for their mania regarding carefully curated regularity and exactitude, not when it has made them the richest country in Europe. I briefly toyed with the idea of keeping a running tally of the crops on either side of the canal, a rough estimate of tilled acreage and maturity and so forth; you never knew who back in London might pay for that kind of information, but the warm spring sunshine and the genever I’d had at lunch made the prospect of toil unappealing. I had work enough ahead of me in Delft, anyway.

I walked to the back of the boat where the schipper manned the rudder, his coat open and a wide straw hat pushed back on his great round head. Occasionally, he would make a great show of navigating, tugging solemnly on the rudder, adjusting our course in the canal, though there was little danger of us losing our way, tethered as we were to the horses on the shore.

“A fine day!” I said. The schipper nodded happily and replied in the thick-voweled French they all used when speaking to foreigners.

“It is indeed! The sun is warm, and the horses are pulling fine. We make excellent time today!”

I filled my pipe with studied leisure, making sure he got the chance to see the bag and smell the deep, oaky Orinoco, finest on the continent. When I was sure of his attention, I offered the bag to him.

“Help yourself, my good sir,” I said. And his smile grew broad.

“Dank u wel!” he said, gracing me with his native tongue. He pulled a long-stemmed and highly polished pipe from his belt and generously packed its bowl. He lit a straw from a lantern, and then we puffed in silence for a moment. “Ah,” he said, “good smoke! I thought you Englishmen preferred sweeter leaf, though?” I stifled my annoyance at being tumbled so quickly.

“How did you know I was English?” I asked, lightly, even breezily; I had deliberately spiced my French with a carefully studied Alsatian accent against just such a discovery, apparently to no avail.

“Your pipe, sir,” he laughed, pointing his blue-painted bowl at mine. “Only an Englishman would smoke such fine stuff in a clay nubbin like that!”

I laughed along with him, and between the gifts of tabaco and the chance to demonstrate his wit, he grew loquacious. He talked of many things, useless to me personally but interesting nonetheless. I learned that the VOC had been manipulating the spice market by unloading choice cargoes in Rotterdam and storing them secretly in canal warehouses. I heard about Spanish agents creeping up from Hapsburg Netherlands to spy on the Dutch Republic; one, he vowed, had bought passage on this very trekschuit! Papist incendiaries from Maastricht hid in the wharves of Amsterdam, waiting for the right moment to strike, while scandal threatened a certain Prussian lady and her stable of lovers in the Hague. I wondered if he would add me to the roll in his next telling, a mysterious Englishman trying to convince everyone he was from Strasbourg?

“And what takes you to Delft, sir?” he asked, somewhat too casually for my liking.

“Only stopping for the night,” I lied, knocking my traitorous pipe against the side of the boat. “I’ll be on to Amsterdam in the morning. I’m an artist, and I want to do some sketches of the Begijnhof.” His brows quirked at that, just as I’d intended; let him think me a secret Catholic, on some mission from Rome, so long as Delft had been dislodged from his mind.

We chatted some more, and then I left him to the perilous steerage of the boat into Schiedam, a taxing navigational maneuver requiring a brief touch on the rudder and a shout to the lad driving the horses on the far end of the rope. For the sake of my lie, I made some sketches of the freshly painted windmills while watching the fishwives and farmers embarking and disembarking from the boat. Then, precisely on schedule, there was a whinny from the shore and the horses were dragging us off again, heading north, towards Delft.

When we docked there an hour later, the first thing I did was toss my pipe in the canal. In a tobacconist’s shop in the Marktplein, in the very shadow of the Nieuwe Kirk, I purchased a fine ceramic replacement, long-stemmed with a broad, round bowl around which sturdy milchmaids cavorted robustly in the finest Delft blue.

There was a letter waiting for me at the inn I’d chosen, De Vliegende Vos. With the landlord, Pieter Hopper, I exchanged four guilders for it and some fresh sheets, a month’s rent paid in advance. My room was on the second floor but near the rear of the low-ceilinged building, by a back staircase that would let me come and go without having to pass through the often boisterous main tavern. I admired the small paintings hanging on all four walls of my room, two market scenes, a winter landscape with ice skaters dancing across a frozen canal, and a scene of haymaking in the countryside, the many-towered skyline of Delft in the distant background. When I was certain that mine host had withdrawn fully down the hall, I cut open the sealed letter. It was, of course, from “Grubendol” the unbreakable anagram of Henry Oldenburg, the Secretary of the Royal Society and one of two men bankrolling my little adventure in Delft.

“My dear Malemayns,” it read, in the venerable old Dee cypher so beloved by the savants in London. “Once settled in Delft, make contact with Gerrit van der Bijl, a clerk in the office of wine-gauging and a subordinate of our quarry; he is our man, and will acquaint you with our target’s schedule and movements. H—” (here Oldenburg cleverly hid Robert Hooke behind a simple letter, an exigency necessitated by the difficulty of anagrammatically rearranging Hooke’s name into anything as euphonious as “Grubendol”)—“believes that the secret of his technique will be discoverable in his private workshop. Notes, schema, and diagrams are most desired. At all costs, do not be discovered. Send news via the usual channels.” I memorized the pass phrases I was to use to identify myself to van der Bijl, then burned the letter in the grate in my room.

I opened the small window and looked out over the canal behind the inn. Somewhere out there in Delft, at that very moment perhaps, my target was engaged in his secret researches. I filled my new pipe and lit it with a splinter kindled from the ashes of the secret letter. Watching my smoke rings rise into the afternoon sky, I saluted my prey, wherever he was.

“Antonie van Leeuwenhoek,” I said, with solemn grandiosity. “Polish your lenses well; soon their secrets will be mine.”

I breakfasted in a coffee shop on the Voorstraat, leisurely enjoying cup after cup of rich, sweetened coffee with the ubiquitous spiced cookies so beloved by the Dutch. The café was busy, but a cheery fire burned in the tile-backed fireplace, the windows had been thrown open to let in the fresh air, and as I knew the Stadhuis would not be open for business until after ten, I was in no particular hurry. I ordered another cup of coffee, this time with a genever chaser, and reviewed the dossier I’d memorized on my target.

Leeuwenhoek had started life as a drapier, a decently remunerative career and one in which he found some success. In particular, he had gained some fame in the city for having a particularly keen eye for quality—his linen was considered the finest in the region, and his yarn was free of the usual flaws. He was a sober enough businessman and a stolid enough Christian that he soon received a number of plum appointments to the municipal government of the city—his technical acumen rewarded with the title of land-surveyor, made later the chamberlain of the courts, and, most recently, he’d been named the wine-gauger for the whole city. Nothing succeeds like success, as they say, and with each appointment Leeuwenhoek grew in esteem among his fellows and in prestige among his peers. A comfortable and respectable upper-middle-class life all around.

A man must have his hobbies, however, and Leeuwenhoek’s was optics.

“Probably got into it from his work in the cloth trade. It’s a small step from merely inspecting cloth with a lens to grinding your own.” Oldenburg had said on that gray, wet winter’s day in London. Summoned by the shadowy eminence himself, I had of course hastened to his house on the Pall Mall; I’d worked with him before regarding the liberation of some jealously guarded metallurgical techniques belonging to the Nuremberg bell-makers guild, and knew him as both generously remunerative and, perhaps more importantly at that point in my career, as offering interesting and unusual jobs. And that had been back before he’d become the Secretary for the newly chartered Royal Society, an appointment promising richer rewards and greater challenges.

“Not that small of a step, Henry,” Robert Hooke had snipped from his corner chair, the third member of our little cabal; his great dark eyes had flashed at me through the crystal of his goblet. “The art of lens grinding is a delicate one, and difficult to master. Which is why I am not sure I entirely believe this Dutch shopkeeper has done what he says he’s done.”

“Which is?” I’d asked, helping myself to a second glass of Oldenburg’s excellent claret.

“Why, my dear Malemayns,” Oldenburg had said, his unblinking eyes and wide, thin mouth reminding me of a toad. “Leeuwenhoek claims nothing less than to have discovered a new, hidden, secret world.” Hooke had snorted at this, but I’d seen the sharp hunger in his eyes.

“He was introduced to us through de Graaf and Huygens; a ‘curious’ and ‘industrious’ man of no small talent, they said. His early microscope work is indeed admirable, even you must admit that, Robert?”

“His bee stinger was well described,” grunted Hooke. “A good eye for detail. Perhaps too good.”

“Later, we received some rather, hm, unusual letters from him,” Oldenburg had said, leaning back in his chair and petting, like a recalcitrant cat, the stack of parchment on his desk. “Our cloth merchant had become interested in a pond nearby, someplace called Berkelse Meer. He noticed a certain seasonality in its waters, clear in the winter, clouded in the summer. Finding his usual microscope too weak for the task at hand, however, he began to experiment with, according to him, a new technique in the construction of a lens. The results, if they’re to be believed, are rather … startling.”

“They’re impossible!” sputtered Hooke, his face flushed. “A magnification of five hundred times? With a single lens? Using my best compound lenses, I’ve only ever reached a hundred-and-fifty-times magnification! A single lens! It’s not possible, simply not possible. The focal distances, I mean, really, it’s absurd!”

“But,” I had said, “surely gentlemen, if I am here, you cannot believe that it is actually impossible, can you?” Hooke had frowned and slumped back into his chair, but Oldenburg, ever the spymaster, had merely grinned.

“Given the nature of the lenses he has admitted to grinding,” said Hooke, after he’d composed himself, “it is impossible. That said, his descriptions imply that there is something to his technique—he is experienced and careful in his observations, and seems aware of the dangers of defects and distortions inherent in the glass when doing this work. And he has had success with algal cells from his pond, and there’s some rather fine earlier work on the rind of a cheese, all things tallying with my own observations.”

“But there’s more?” I’d asked, enjoying the squirming consternation of these savants.

“Damnably more,” scowled Hooke.

“Here,” said Oldenburg, riffling through the papers at his elbows. “I translated his letter. Let me read it to you.” He scanned the page with a careful eye until he found the passage he was looking for. “Ah, here, from a letter on the mere: ‘Among these streaks there were besides very many little animalcules—’, I should say,” said Oldenburg, interrupting himself, “the word he uses, the Dutch that is, diertjes. ‘Dier’ means animal, and the suffix -jes represents a sense of the diminutive, the exceedingly small. Thus: ‘animalcule,’ a word of my own devising for this, hm, curious concept.” An indulgently smug smile quirked the broad slash of his mouth. “Our dear Mr. Hooke is not the only coiner of terms, you see? Now, where was I? Oh, yes: ‘And the motion of most of these animalcules in the water was so swift, and so various upwards, downwards and round about that ‘twas wonderful to see: and I judged that some of these little creatures were above a thousand times smaller than the smallest ones I have ever yet seen … ’”

“A thousand times!” shouted Hooke, and I’d heard the disbelief, jealousy, and grudging admiration mingled in his voice.

“He has, it seems, made some drastic advancement in the construction of a new, more powerful microscope. It is the details of this new technique, this new construction, that we want,” had said Oldenburg, leaning towards me, his long fingers meshed.

“A thousand times,” Hooke had murmured, and the light in his eyes had turned inward as he spoke to himself, all else forgotten. “A whole world in a drop of water!” The awe in his voice had sent a shiver down my spine.

Thus began my brief apprenticeship in the art of lens grinding and microscope manufacturing under the unforgiving tutelage of Robert Hooke. I would never be a philosopher, that much was clear; even as a mere grinder of glass, I’d have had a hard time earning a crust, but I learned enough to know what to look for, what to sketch and observe and report on in Leeuwenhoek’s workshop. The trick, of course, would be to get the opportunity—the Dutchman was quite secretive of his new technique; he worked alone, jealous against the release of even a hint of how his new microscope was designed or operated. He would neither describe his technique nor share his finished microscope, offering only the signed affidavits of Delft’s sober religious and municipal leaders that he was not merely dreaming up these wriggling things a thousand times smaller than even the tiniest mite.

The bells of the Nieuwe Kirk tolled ten, a song echoed soon after by the deep brass tones of the Oude Kirk’s tower. I finished the last of my coffee; It was time to get to work.

I strolled through the bustling Marktplein, pausing at various stalls and open-air shops to make a show of perusal. I feigned knowledge of ceramics and glassware and pewter, or pretended to be interested in the size and maturity of leeks and spring onions and young tender asparagus, all the while actually walking the perimeter of the Stadhuis. It was an impressive building in the middle of the plaza, heavy stone walls pierced by tall, graceful windows of delicate stained glass. The iron double door was thrown wide, and people, citizens and city workers alike, came and went, a hive of activity. I bought a guilder’s worth of Moluccan nutmeg and a rather clever brass spice mill and then made my way up the broad double stairway and through the great door of the Stadhuis.

When the old Stadhuis burned, the city fathers had been adamant that the new building would reflect the importance and wealth of their little city. They’d kept their word; whatever Tyrolean marble salesman they’d contracted was doubtless even now enjoying the villa he’d purchased with his fee. Floors, walls, columns, all carved from red-streaked roiling stone, and the colored light pouring in through the stained glass bathed the whole hall in a rainbow glow.

The millstone of Dutch bureaucracy ground slowly but finely—I was routed through three different information desks on two separate floors to collect the necessary stamps on a pass that I was able to exchange with a burly door warden for access to the offices of Delft’s Municipal Department of Imports and Excises on the third floor. A crabbed little man who looked like he’d sprouted like a mushroom from his work stool carefully went over the stamps and signatures and endorsements on my stamp, making sure each one was in order, before turning his fungal gaze upon me.

“Meneer van Leeuwenhoek is not in at the moment.” He had exhaled the words like a priest delivering the sacrament.

“Even so,” I replied, “perhaps there is someone with whom I could speak today, now? I merely require a brief discussion with a competent authority regarding a potential shipment of gewürztraminer, and of course, a schedule of fees and duties. I have spoken to my sellers in Strasbourg many times about the rapid and smooth functioning of Dutch offices,” I said, leaning in with my most unctuous smile, “and I would like to show them the truth of that by sending a letter with that information today.”

The little toadstool’s patriotism had been aroused, and there was nothing for it but to find a functionary for me. He turned on his creaking stool to ask a question in Dutch (which I pretended not to understand) of another toadstool at a similar desk.

“Who is in that can answer this pushy Alsatian’s questions?” asked mushroom the first.

“Van Leeuwenhoek is out,” replied mushroom the second, his sour features placid as a bog.

“I know that, of course, and what’s more, I’ve already told him. Therefore, I ask again, who among the junior officials is in?”

“Today?”

“Today.”

“Berkenbosch is out,” mused the second mushroom, settling into his stool like a broody hen.

“Sent to Zutphen to deliver some reports,” corroborated the first mushroom, nodding.

“Just so,” said the first, joining in with his compatriot’s nodding. “And van Wolfswinkel too is not at his desk, I noticed.”

“He was dispatched on a glass-buying trip by van Leeuwenhoek on Tuesday and will not be back until Monday next.”

“Then, I suppose, that leaves young van der Bijl, doesn’t it?”

“Just so.” The first clerk spun around in his stool, aglow with the warm light of satisfaction found on all civil servants who are in a state of grace. “Menheer van der Bijl will be able to assist you with your inquiries, sir,” he said, switching back into French. Matching his placidity drop for drop, I bowed low my thanks and followed the ray of his outthrust finger towards a grubby little door at the back of the Office of Wine Assessment. I knocked, but waited for no response, driving in with all the bluster native to a pushy Alsatian.

“Monsieur van der Bijl? Goedemorgen,” I said, loudly butchering the Dutch for the benefit of the whole office. The little moon-faced functionary belonging to the name blinked several times up at me—I merely smiled and closed the door behind me.

“—” van der Bijl opened his mouth, but I shushed him with a raised finger and a curt little shake of my head.

“Ut!” I said. “Now,” I cleared my throat and leaned forward, with van der Bijl leaning backwards to compensate. “‘The apple trees will be in bloom very soon,’” I quoted. The little man’s throat bobbed.

“Ah, that is, hm,” he said; I could see his brain turning around and around, like the vanes of a windmill.

“‘And the bees … ’” I offered, by way of a hint.

“Ah! Yes! ‘And the bees will be swarming before long!’”

Thus mutually assured of the other’s identity as a coconspirator, we shook hands merrily and got on with our business.

“My dear van der Bijl,” I said, “what do you know of van Leeuwenhoek’s microscope work?” The little man resumed his manic blinking.

“Microscope?” he said; there was sincere puzzlement in his voice. “Microscope?”

“Forgive me,” I said, bowing in my seat, “his ‘aalkijker,’ to give it its good Dutch name.”

“Oh!” said van der Bijl, nodding his head. “The glass and metal contraptions? That is what you are interested in?” Relief blanketed his butter-colored face. “I was afraid you were blackmailing me to do something serious, like betraying the wine import schedule to a trade consortium.”

“I assure you, Leeuwenhoek’s ‘glass and metal contraptions’ are very serious business. And please, ‘blackmail’ is such an ugly word—think rather of your Antwerp indiscretions as an opportunity to earn a little extra money outside of normal business hours, eh?” The little office worker paled a bit at the reminder of the hold I had over him, but he rallied quickly enough.

“Of course, of course,” he said. “You wish to know about van Leeuwenhoek’s hobby? Well, he makes no secret of it—he has found many remarkable things, whole worlds in a drop of water, or so they say. The elders of the church have gone in to see his remarkable machine, as have many members of the city council, and they all agree, indeed have signed affidavits—he has found a new world!”

“C’est incroyable,” I said. “But you have never seen it yourself?”

“But no, of course not, I am not nearly important enough—indeed, of the staff, only Old Aardewijn, who has worked with van Leeuwenhoek for the past twenty years and who came to the wine assessor’s office with him, has been invited into the workshop.”

“And where is this workshop?” I asked, gesturing towards where a window should have been in van der Bijl’s closet of an office.

“In his house,” said van der Bijl, simply. “It’s called the ‘Gulden Hoofd,’ right off the Hippolytusbuurt gracht. Good neighborhood; a nice little place, by all accounts, not a palace, oh no, but large enough for his family and servants. I have heard him refer to his workshop on the first floor, near the back, above the ground floor.”

“‘The Golden Head,’ eh?” I said, nodding my own head at the name. “How many staff does he keep?”

“Oh, the usual,” said van der Bijl, waving his hand airily. “A cook, a boy for errands, a few housecleaners. Once I took some papers there for him to be sign and there was an old doorman, a kind of general dogsbody I believe.”

“Enough to be underfoot,” I mused. Then, clapping my hand on my knee, I announced my decision. “My dear van der Bijl! There’s nothing for it—I must get inside that workshop of his and be given the chance to examine his papers and various apparatuses without interruption.”

“I can’t see how you’ll do it,” he said, frowning. “The workshop is attached to his personal study—they’re not likely to let you in without van Leeuwenhoek being there, and if he’s there, you’ll not be allowed to see the workshop at all.”

“I shall employ what we in the trade call ‘clandestine methods.’ Now,” I leaned back in my chair and removed my notebook. “Let us proceed to the details of the household’s schedule … ”

I spent the next half-hour minutely examining everything van der Bijl knew about the comings and goings at Het Gulden Hoofd, which, scanty though his knowledge was, still provided me with the opening I sought. Market days were discussed, and with them, a timetable was drawn up wherein the least number of servants would be at home. More importantly, I learned of van Leeuwenhoek’s springtime picnic tradition—in three days, he and his whole family would adjourn to the Delft countryside for a day of bucolic merrymaking. That this date was certain was adduced from a memorandum van Leeuwenhoek had left for the office, letting them know he would be unreachable for the duration of that day.

“Too good of an opportunity to miss,” I said, underscoring the date in my notebook.

“But there will be servants there,” said van der Bijl. “How will you get into the workshop?”

“Ah, dear comrade,” I grinned like a cat. “That is where you come in.”

The inside of the crate was snug; it wasn’t long before I was missing the second pillow I’d left behind in my room, but all things considered, it wasn’t a bad piece of work. It had taken me a day scouring the canal warehouses to find one just the right size, big enough for me to fold myself into with reasonable comfort, but not so big as to arouse suspicion. Still, van der Bijl had been skeptical when I’d shown it to him.

“You can fit in there?” he’d said, peering into the box when he’d visited my room at the inn.

“I’m surprisingly limber for my size,” I assured him and demonstrated by pretzeling myself into the box.

“Surely you’ll suffocate?”

“Not so!” I grunted, unwinding an arm to point at the cleverly concealed gaps along the joints in the box. “Plenty of air circulation here, even with the lid on!”

“But how will you get the lid off from within the box?” he’d asked. I wiggled my way upright and showed him the modifications I’d made.

“Observe,” I pointed to the outer surface of the lid. “When I set the lid on the crate like so, you see these nails? It appears to have been completely sealed, nailed shut. However, when I turn the lid over, like so, you see that, in fact, the nails are mere illusion, foreshortened and attached to nothing. Now, look at these latches I’ve affixed to the inside of the lid—they are of a sort used by timber handlers to secure planking for transport. See? From within I twist them like so, and et voila! Latched shut. When I am ready to exit my conveyance, an opposite turn, and I am free.”

The little office worker shook his head, but his hand drifted to the reassuring weight of the guilders I’d put in his pocket, and he shrugged.

“It seems an awful lot of work for some bits of glass, but as you say!”

“Just so. Now, when you come tomorrow morning, don’t knock—the room is supposed to be empty. Simply enter with your men—you have found some men?”

“Yes, a pair of stevedores from the canals, strong and particularly uninquisitive, as specified.”

“Excellent. Enter, have them take up the crate, and then transport it, and me, across town to Leeuwenhoek’s Gulden Hoofd.”

“And you think it will work?”

“What could possibly go wrong? A box of delicate technical mechanisms, very heavy, for Leeuwenhoek, delivered to the office by mistake? So you, conscientious little underling that you are, take time from your own work to see that it arrives at its destination. Ah, but Meneer van Leeuwenhoek is out? No matter, just tuck the crate in his workshop, he can look it over at his leisure then, there’s a good chap! Elegant in its simplicity.”

It was indeed, though had I actually been delicate technical mechanisms I should’ve preferred more packing—the burly fellows van der Bijl employed jostled me most violently, particularly when taking me down the stairs and loading me into the back of the handcart; I felt every rut and bump in the Delft streets as we made our way across town. It was still and stifling in the crate, but tolerable, although I lamented the bruising that I was taking.

We arrived at the Gulden Hoofd and, muffled though it was, I heard the bright clash of the brass door knocker, followed by the dulcet Dutch of van der Bijl and the noticeably creakier speech of one whom I presumed to be the aged doorman he’d spoken of earlier. It all seemed to be going well enough—van der Bijl spoke his lie just as I’d pronounced it to him, trippingly on the tongue, but a minor impediment appeared when the issue of the locked workshop was raised.

“But, sir,” wheezed Methuselah, “I don’t have the key to his room. Only the Master has a key, on his key ring.”

“Ah, well, ah, hm,” went van der Bijl, or some such noises. The weak point in any plan, of course, is relying on other people. I ground my teeth in impotent frustration, trapped in the crate, willing the fool to persist in the operation.

“Perhaps we could simply leave it outside the Master’s door?” asked the wise old man, whom I now envisioned properly adorned with a long white beard, as befits one endowed with such sublime wisdom.

“Just so, just so!” said van der Bijl, cheerful again at the prospect of being shed of me at last.

Up again went the crate, and I was jostled and bumped up some stairs before being set none-too-gently on a floor. I heard steps and voices, the old man and van der Bijl at the foot of the stairs, their voices receding as they went out.

With all the patience of a serpent, I twisted in the crate, pressing my ear against one of the cleverly hidden air holes I’d put in the box. It was quiet, though I heard the sounds of the household in the distance, crockery being scrubbed and floors being brushed, the melodic refrains of well-ordered domesticity. Once I held my breath as a pair of heavy clomping footsteps came thundering up the stairs, a female voice cursing at the way the workmen had left the box out in the middle of the landing. Vainly she pushed on it, but I had breakfasted heartily enough and remained unmoved. I listened to her moving about there on the first floor, sweeping the landing and polishing windows, and eventually I heard her bumbling back down the stairs to the ground floor.

A door somewhere opened and then closed. Then: silence.

I slid the catches on the interior latches aside, first one, then the other, their oiled hinges smooth and silent as batwings. Carefully, cautiously, I eased the lid open a crack, the width of a guilder. No sounds.

Opening it wider, I got my eyes out and into the open—I was on a landing, behind a banister at the top of a stair. Shifting as quickly as I dared, I saw that I had indeed been placed on the threshold of a doorway, a huge oaken thing, sturdily built and with heavy iron fixtures. Silently, I slid out of the box, staying low and close against the wall, though had anyone walked out to the foot of the stairs, they would’ve surely seen me. I would have to move quickly.

The padlock on the door was of Swedish make, barrel-shaped with a carved swing shackle and finely fluted ward springs, a well-made piece of hardware, though hardly insurmountable. The wire hook and the long, thin jeweler’s chisel in my pocket made quick work of it, and with a crisp snap, the lock gave way. I pushed inside and quickly shut the door. Unfortunately, there was no way to relock the mechanism from within; I would simply have to rely on that greatest of thieves’ tools, luck.

That this room was the very lair of Leeuwenhoek was immediately evident—a canopied bed, well-used, stood in one corner, and the desks and tables and chairs all had a lived-in look, the result of regular, daily use. I removed my shoes and prowled the room silently in my stockings. I crouched by the fireplace and felt the wan heat of the embers left by this morning’s fire, noting the comfortable slippers and housecoat thrown carelessly over the back of a well-stuffed reading chair. Numerous paintings lined the walls, nature scenes and cityscapes, and those amusing little portraits of exaggerated expression the Dutch called “tronies.” A bookshelf loomed near the window; in it I saw Hooke’s Micrographia among other treatises of natural philosophy. Opposite the shelf was Leeuwenhoek’s Wunderkammer, full of shells and bones and preserved animals or bits of animals. All together a comfortable and pleasant room for a gentleman scholar, though it was obviously not his workshop proper. The room had, however, been recently partitioned, and so I quickly (though quietly) made my way to the inner door piercing the newer dividing wall. I pushed it open and entered the holiest of holies.

The room was long and narrow—barely five feet wide but a good twenty or so deep, with a window at the far end of the room. A kind of long table ran the length of the room, and on it were strewn thickly scribbled papers and a variety of tools. I made a quick perusal of his scattered notes; they made for strange reading, and I felt that, perhaps, there beat the heart of a poet in his stolid Dutch breast after all, for much of his writings seemed fantastical almost to the point of whimsy. Small things “danced” in his glass, weaving like spritely figures through some dim twilit scene. The flicker of tiny limbs, the pulse of alien organs, and in such teeming numbers, seemed to affect Leeuwenhoek greatly. He marveled at the swarms of life in a drop of pond water, thousands and thousands of little lives invisible to us that he, mirable dictu, was the very first person ever to behold. There was also, among the fancy, a tone of awe, a sense of terrible wonder—he saw his little animalcules waging war among themselves, on occasion, one scudding little mote trapped and devoured by another. Over and over I kept running into the same scribbled phrase: “Wat doe je als je dingen zie dat niemand ooit heeft gezien?” What do you do when you see things that no one has ever seen before?

As interesting reading as they were, I set aside his observations and turned my attention to his many tools—much can be quickly learned from the kinds of tools and their state of repair in a workman’s shop, and Leeuwenhoek’s was the proverbial open book.

Tools for metalworking were in abundance, of course; gougers and flexion pipes, grips, cambrels of all sizes, and chisels, of course, but there were rarer pieces too, Regensburg planes and jointers for all conceivable angles, each stamped with the Shield of Turin, costly specialized equipment, each one made to order. Near them I saw the product of Leeuwenhoek’s labors, brass tubes and fasteners whose purpose I recognized, but also a number of flat copper plates with central slits and oddly angled mounts on them, with truly remarkable screws, custom lathed by Leeuwenhoek himself, attached to the plates; these were a mystery to me, and so I quickly sketched them in my book, noting their dimensions carefully.

Nearby a number of examples of the types of microscopes that Hooke had diagramed in his Micrographia were two single-lens tubes and a larger compound affair bolted to a stand with an adjustable objective—these I recognized from my work with Hooke himself and saw that they were delicately made and expertly turned-out pieces of work, much finer than anything I, poor student of the art that I was, could ever have made. But they were also dusty—clearly they had not seen use for a long time. Chuckling at the image, Hooke boiling over at the indignity of his cast-aside designs, I turned my attention to Leeuwenhoek’s lens grinding set-up.

There were the usual hand and pedal lathes, of course, the sort cherished by all good grinders of glass, though it was striking that these too seemed to have been set aside—dust had accumulated on them, showing that Leeuwenhoek had not been at his grinding for many months. And yet his microscopy work had continued—Oldenburg had, I knew, been receiving more letters, more drawings, more descriptions of the impossibly tiny worlds surveyed by Leeuwenhoek. If our little Dutchman hadn’t been grinding his lenses, how was he making them?

Unusually, there were a number of burners in his workshop, some very large ones with deep reservoirs for the spirits that fueled them, capable of producing remarkable heat. I sketched them quickly and took care to illustrate the pipes and tongs there, too. Was this then the Dutchman’s secret? Leeuwenhoek was blowing glass, trying to produce lenses in that manner perhaps. Hooke despised the blown lens; the clean convexity needed for good optical work was too difficult to control, and the resultant lenses were too large for proper magnification anyway.

Leeuwenhoek did have a large supply of glass rods, the finest quality glass in fact, carefully packed and stamped with the seal of Venice. I needed to find his notes to understand how he made use of them. There was, of course, no organization here—I was glimpsing his work suspended, as it were, in a moment of time, and so I was forced to quickly scan the papers and books and sheafs of parchment scattered across the tables, a tangle as dark and mysterious as any jungle. For a moment, I feared his secret would remain hidden behind the impenetrable cipher of Leeuwenhoek’s execrable handwriting and impressively inconsistent spelling, but then, as if guided there, my eye landed on a small sketch, much labored over with many corrections and clarifications.

I stifled my shout of triumph, for here was Leeuwenhoek’s genius, laid out in stark black ink.

A candle flame, a rod of glass heated, then stretched, and heated and stretched again and again until rod became thread, and, finally, the glass thread melted, and a tiny droplet, a perfect bead of glass, would drop, sparkling, from the thread. Tiny, tiny beyond imagining and rounded to perfection by nature itself—it was the perfect lens, finer and more powerful than any crude ground glass! Simple! And efficient! Why, dozens of these beads could be made in an evening, examined under a hand glass for the most perfect, the roundest example. Remarkable indeed!

But then a second, new mystery arose—the secret of the lens was mine, but how did Leeuwenhoek use such tiny bead lenses? The object of study, the sample in question, would have to be ridiculously close to the lens, practically right on top of it, and then the eye of the observer would have to be similarly close—the merciless laws of optics were unforgiving on these points. Sample, lens, eye of the beholder, all would need to be remarkably close to make practical use of such a theoretically powerful microscope. By what mechanical arrangement could Leeuwenhoek achieve this?

The mystery of the metal paddles came suddenly to mind. Darting back to them, I squinted down at the strange device, a thin silver rectangle with a central slit-like vacuity and with two sets of screws at right angles to each other mounted on its face.

There, sparkling in the slit, was a tiny bead and, behind it, the merest hair-breadth distance between them, was a small needle with a tiny, flattened stage. This strange fan-like affair, this paddle of metal … this was Leeuwenhoek’s microscope!

The mystery of the screws was revealed to me as well, for I saw the ingenious way Leeuwenhoek had lathed them and affixed them to his device; by a simple rotation of each, the sample stage would move in or out, up or down, a remarkably precise approach necessitated by the infinitesimal distances and incomprehensible magnifications of the machine.

My hand flew across my earlier drawings, and I made careful annotations of the placement of the bead and the way the screws had been manufactured. Leeuwenhoek was indeed a genius of singular power—the problem of both lens and its manipulation had been ably solved by the redoubtable Dutchman. I saluted him, even as I stole his carefully guarded design for Oldenburg, Hooke, and England.

I had many pages of diagrams and descriptions now. By all rights, my task was complete, the secret of Leeuwenhoek’s design safely secreted away in my notebook, awaiting merely the brain and hand of Hooke to translate them into metal and glass back in London. But the question that Leeuwenhoek had asked himself, “Wat doe je als je dingen zie dat niemand ooit heeft gezien?” echoed in my mind. What do you do when you see things that no one has ever seen before?

Ignoring the delay, I obeyed my impulse and snatched up the silver microscope. Working from Leeuwenhoek’s own notes, I prepared a sample, filling a small, clear vial with murky water from the large crock under the table. Carefully adjusting the screws, I safely lodged the vial into place on the sample stand.

The light was, as with all microscope work, somewhat tricky. From his notes, I knew that Leeuwenhoek’s device needed good but diffuse light, preferably natural but not too bright. I was in luck, in that the afternoon sun shone glancingly over the rooftops of the neighboring houses and sent a warm glow in through the window at the back of the workshop. It took some doing, and I must have cut quite the figure, twisting and turning about, first lifting my face then lowering it, squinting into the strange device pressed close to my eye.

At first, and until I’d found the perfect lighting, there was only a kind of fogginess to be seen; I very carefully adjusted the screw that controlled the objective; strange dark motes floated indistinctly and with a blink would vanish, or turn suddenly white and woolly, but then, with the suddenness of a thunderbolt, they snapped into focus, and I saw then what Leeuwenhoek had seen first and I gasped.

It was as if I had been suddenly transported into a dream—I knew, of course, that I was standing in a workshop in a house on a street in Delft, as prosaic a place as any, and yet, by simply closing one eye and seeing with another, Leeuwenhoek’s lens had thrown me into another, impossible world.

The things did indeed seem to dance, as Leeuwenhoek had said, but not to any sane notes—indeed, their sarabands seemed set to some infernal music, the sort of furious songs wailed by witches celebrating their sabbaths among the wild crags of the Brocken. Semi-translucent ovoids rippled with submarine indolence, whispy threads curling and flexing like seaweed in a tidepool, and then—suddenly, as if whatever devil was beating time had switched to a faster tempo—the writhing things would dart here or there, seemingly seized with the bacchic fury of the maenads.

Some of the shapes were gelid and soft-looking; others had an almost austere, crystalline appearance, hard and sharp-edged and armored all around with strange overlapping plates. Some were solitary, spinning sedately in their medium, while others milled about in great mobs, clumped together like gossiping fishwives or chained like the damned along a single endless thread. Horribly, one shape, larger than the rest, oozed and flexed and flowed over and around and between them, its whole amorphous body running like mercury with what I soon saw was a terrible, willful hunger, for the rippling thing fell suddenly like a hawk out of the sky to engulf one of its neighbors. A mad, panicky laughter rose in my throat as I found myself thankful that Leeuwenhoek’s interest was merely optical; what must those things sound like down there? Soft grasping bodies squelching against armored foes, bubbling between the interstices of matter, screaming with pleasure as they devoured one another, and above all, the ceaseless susurration of the feathery hairs that rippled and danced and waved.

And there were so many! Thousands indeed there must’ve been in that little vial of water, a jungle’s worth of flopping, floundering shapes that had, until now, writhed and wriggled and lived and died invisibly all around me. Skin prickling with sudden horror, I imagined the seething hordes of them in the crock under the tables, holding its gallons and gallons. God in heaven, how many were in there? Delft had what, twenty thousand souls? London, a half-million? I did laugh then—what were those numbers to the things in the crock, millions upon millions upon millions of lives. Jugged in a crock, in a house, in a city! And where had Leeuwenhoek gathered his little universe? A mill pond outside of town, Oldenburg had said—ridiculous! How many worlds-worth were there in a millpond? The pomp and vanity of humanity, all its pride and struggles, the whole of its history known and unknown—what feeble emptiness, what thin bloodless scarcity when compared to the countless hordes in a millpond, whose numbers must have dwarfed the stars in the sky.

I reeled, and it was only the sudden weakness in my arms and mind that kept me from dashing Leeuwenhoek’s hellish lens against the wall—to have seen what no one else had seen … how had he withstood it? I felt as if I were on a cliff, high over a valley, with the clouds streaming beneath me. Man is but a small thing, the philosophers say, and yet how small they cannot truly understand! Bede’s sparrow, flickering for one brief moment through the warm hall, is on too generous a scale—say rather, a mote of dust caught and lost in a sunbeam, a grain of sand sparkling on the beach and drowned in a wave, a puff of smoke whirled into the sky!

How I got out of the workshop, I do not know; perhaps I went through a window, for I do seem to recall a spinning, whirling sense of motion, though I cannot remember. I know I wandered the streets for some time, for the sun was very low when I seemed again able to perceive humanity’s world again. A woman called to me from a doorway, beckoning, her blouse open, her smile wide and inviting, and yet I could regard her only with horror—what things teemed on her skin, on her teeth, in her very breath, what worlds of wild horror lived on and within her?

I turned and ran, splashing through a puddle (perhaps I had been the instrument of some Armageddon there in that puddle, millions and millions dead beneath my boot), fleeing from all contact, shrinking from the vastness of the sky overhead—who knew what alien eye looked down on me at that moment!

I found myself at a canal, staring down into its cool black surface. The stars were coming out overhead, but their reflections in the gently rippling water reminded me only of the things in the microscope I had seen, and I sobbed with horror. For a moment I entertained the thought of throwing myself in, of swimming to the bottom and filling my lungs with the filthy water, but the thought again of the worlds, or the universes of life down there, in the canals, in the miles and miles of them, sent me reeling back from the brink to huddle against the nearest wall, taking facile comfort in its false solidity. I shivered and hid my face behind my hands.

What do you do when you see things that no one has ever seen before?