In composing this painting, Vermeer may have used either a convex mirror or, more likely, a double-concave lens. Looking at a seated woman through such a lens, perhaps mounted in a frame like Dou’s device, Vermeer would have seen spatial distortions such as those depicted in his picture. The seated girl would have been small in comparison with the objects in the foreground. Although no one is seated opposite her, the viewer imagines that a man sitting there would be disproportionately large. Through the lens, Vermeer would have seen the tabletop at a tilted angle, again because of the distortions caused by the curved shape of the edge of the lens. Indeed, having painted the tabletop in this tilted way, Vermeer found himself having trouble setting his still life convincingly on top of it; x-ray analysis shows he repainted this bowl of fruit a number of times. As in The Procuress, he was forced to obscure the way the objects sat on the table with the folds of drapery and carpet. Although he had experimented with mirrors while painting The Procuress, this is probably the first time Vermeer used a lens in composing a picture.
Evidence suggests that he may have used a lens in this way while composing two other pictures from this period in the late 1650s: Cavalier and Young Woman and The Letter Reader. The latter shares a number of motifs with A Maid Asleep, in particular the carpet-covered table and the askew fruit bowl. In each of these later paintings, the scene resembles a wide-angle image seen in a concave lens, in that the subjects in the foreground are disproportionately large compared with those in the background. But in Cavalier and Young Woman we see the way that Vermeer modified the optical images to suit his artistic choices for the painting. The enormous bulk of the soldier, closest to us, dominates the rather small girl on the other side of the table, even more than would be expected with a wide-angle lens. Rather than compensating for the disproportion, Vermeer increased it, strengthening his final design. The man looks big, solid, and important as he sizes up his petite conquest.
In this manner Vermeer set the pattern for how he would use optical instruments throughout his career. Looking through lenses, he saw the world in a new way, one that he wanted to capture on his canvas. But he also felt free to alter the images he saw with those optical instruments, relying on his artistic instincts to make different choices when they improved the final design. In a time—and place—of burgeoning interest in optics, and excitement about the possibilities offered to the artist by lenses and mirrors, it is no surprise that a young artist trying to make his name would want to be seen as au courant with the latest technology. One cannot help but notice that Vermeer’s interest in looking through lenses arose right at the very moment the same interest awakened in his neighbor Antoni Leeuwenhoek.
*1 Jannetge was the daughter of the candlemaker Rochers van der Burch and the sister or stepsister of the painter Hendrick van der Burch. In 1650 there were six residents of Delft with the painter’s name, at least one of whom does seem to have been related to Leeuwenhoek’s mother.
*2 Even with today’s more perfect mirrors, artists continue to use them to learn more about their subjects, by seeing them in new ways: reversed, inverted, and from different angles.
PART 4
Learning to See
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IN HIS SHOP on the ground floor of his house on the Hippolytusbuurt, Antoni Leeuwenhoek carefully wrote out a bill for Pieter Heijnsbroeck, a builder from Rotterdam who had just purchased “4½ ells [about 4.5 meters] red kersey … 2½ dozen buttons and button-loops … 1 ell white bombazine … [and the same of] raw silk.” He dated the bill December 19, 1659. Heijnsbroeck owed six guilders, eleven stuivers, and eight pennings.*1 Leeuwenhoek’s wife, Barbara de Meij,*2 may have been present there, quickly and neatly wrapping the purchases in brown paper and handing them to the customer. Later that week, Heijnsbroeck, who has relatives in Delft, will return—the Rotterdam-to-Delft journey takes only part of an afternoon and costs a mere five stuivers for a ferry—and purchase two ells of a wide ribbon for six stuivers, which Leeuwenhoek will add onto the same bill. The builder’s debt would be paid off only on June 15, 1660, as Leeuwenhoek will fastidiously record at the bottom of the receipt.
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Leeuwenhoek had married Barbara de Meij on July 19, 1654, soon after he returned to Delft at the end of his apprenticeship in Amsterdam. Barbara was the daughter of Elias de Meij and Maria Virlin.*3 Elias was a cloth weaver of Dutch origin who had been living in Norwich, England. He and his wife were in Delft by December of 1629, when Barbara was baptized—making Barbara a few years older than Antoni. It is likely that Barbara’s father had been born in England. The records of the Dutch Church in London show that an Elias de Mey (as the name was known in England) was an officer of the church from 1581 until his death in 1583; this may have been Barbara’s paternal grandfather. He had married a woman named Tanneken Simons in 1572 (probably this was a second marriage for him). A Deborah de Meij listed in the marriage register as “a young lady from Norwich” married in Delft in 1617; Deborah was probably the sister of Barbara’s father, suggesting that some of the De Meij clan emigrated to Delft around that time.
Barbara’s father and aunt, then, would have spoken English as a native language; although Barbara was born in Delft, she must have heard English spoken in the home at least some of the time. When Antoni Leeuwenhoek, a young man just starting in the cloth business, returned to Delft, the fact that he spoke English he had learned during his apprenticeship with the Scots Davidson may have helped win over Barbara and her mother (her father was dead by this time, having been buried in May of 1646). It was not unusual for a young man to marry the daughter of someone in his own profession; Barbara would have been familiar with the cloth trade from her father’s activities. She may even have helped out in his shop as a girl, learning how to wrap up packages for customers and perhaps even how to write out receipts. Unlike girls in the rest of Europe, girls in the Dutch Republic had levels of literacy and writing ability that approached the levels attained by boys. When the French religious scholar J. J. Scaliger arrived in the Netherlands in 1593, he was scandalized to find that girls—even maidservants!—could read.
Around the time of their marriage, Leeuwenhoek purchased the home that he would inhabit for the rest of his life, a house called The Golden Head in the Hippolytusbuurt, a street running parallel to the Oude Delft (the main canal and thoroughfare of the town), near the Town Hall and the fish and meat markets. The house and the interest on the loan Leeuwenhoek needed in order to buy it cost him an astonishing 5,000 guilders (about $76,200 today); Leeuwenhoek had to borrow much of that amount, and agreed to pay it off with a combination of cash and goods. The young couple must have felt extremely fortunate that they were safe, and their house still standing, after the munitions explosion a few months after their marriage. Indeed, it was a particularly good time to have begun plying the cloth trade in Delft: after the devastating event, Leeuwenhoek was probably busier than ever, selling cloth to Delft citizens who had lost all their clothes in the explosion and fires that followed. This would have made the period especially lucrative for the town’s clothiers—compared with other household items, such as kitchen furnishings, personal clothing was at the high end of cost per item. For example, a pewter bowl might cost a few stuivers, while a women’s blouse would cost almost 1 florin (28 stuivers, or about $20), and a full dress for a special occasion could be worth up to 67 florins (roughly $1,400 today). Although clothing was expensive, even middle-class families generally owned a large number of clothing items. For families whose total household goods—including furniture, kitchenware, paintings, and the tools of the husband’s trade—were inventoried at between 700 and 1,400 florins, about one-third of the value would be the family’s clothes. It was not unusual, for example, for a middle-class Dutch housewife to own thirteen different bonnets.
Leeuwenhoek may also have had an additional source of business: selling veils to the members of the thriving local art scene. The artists’ guildhall was not far from his house and shop, and Leeuwenhoek knew a numb
er of artists through his stepbrothers Jan and Gerrit Molijn, who were members of the guild. Artists who used the perspective devices known as the Alberti veils—pieces of sheer fabric with threads running through it in a grid pattern—would need to buy the material from a clothier like Leeuwenhoek. (Unfortunately, only two receipts in Leeuwenhoek’s hand remain extant, and they both record items sold to Heijnsbroeck, so we cannot verify that artists shopped at Leeuwenhoek’s business.)
Leeuwenhoek was a large-framed, well-built man, who probably stood five feet five or six inches (on the tall side for men of his time in the Netherlands) and weighed 160 pounds, as he would for his entire adult life—or so he bragged to a correspondent decades later. From paintings in which he appears, we can see that he had dark eyes and a long straight nose, flared out a little at the nostrils, and wore a light brown wig, long and curled—wigs such as this had come into fashion ever since a vain and early-balding King Louis XIV in France had begun to sport one around 1655 (when he was only seventeen years old). Leeuwenhoek is shown smiling (faintly) only in one image, the last known, an engraving made of him in 1686 by Johannes Verkolje. By that time he had gained weight, and his face is fatter.
He and Barbara would go on to have five children, three boys and two girls; all died in childhood except one daughter, Maria, who—like Vermeer’s daughter Maria—was named after her maternal grandmother. Maria survived to old age and took care of her father until his death at the age of ninety, in 1723. By the time Leeuwenhoek wrote out the receipt to Heijnsbroeck in 1659, his life, it seemed, had settled into a typical course: a successful cloth merchant, a responsible member of civic society, and a husband and father. There was no indication, yet, that he would soon emerge as a leading natural philosopher of the day. But around this time Leeuwenhoek, for reasons no one knows, began to experiment with making his own lenses out of glass.
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This interest in lenses did not come completely out of the blue; after all, Leeuwenhoek had already mastered the use of magnifying lenses to determine the thread counts of fabrics. Lenses were all around Leeuwenhoek, both in Amsterdam during his apprenticeship and in Delft when he returned home. Spectacles were sold not only in shops but also by salesmen in the market squares of the Dutch Republic, sometimes even by sellers going from door to door, as in Rembrandt’s The Spectacles Seller (1623–24). In this painting, which represents “sight” in a series painted by Rembrandt to exemplify the five senses, we see a spectacles seller with a box strapped to his chest, holding it open in front of an elderly couple, the woman seemingly blind, or nearly so. There was already a fad for purchasing magnifying glasses, called flea glasses, which were used eagerly by men and women to examine the small mites crawling from their bread and cheese. The Anglo-Irish satirist Jonathan Swift would later parody this interest in mites:
So, Naturalists observe, a Flea
Hath smaller Fleas that on him prey,
And these have smaller Fleas to bit ’em,
And so proceed ad infinitum.
In 1637, after he arrived in the Dutch Republic, Descartes remarked on “these small flea glasses [lunettes à puces] made of a single lens, whose use is now quite common everywhere.”
In the 1650s, Delft was already known for the quality of its lenses, in part because of the excellence of the glass produced by the local glassworks. (Notably, in the early 1660s Christiaan and Constantijn Huygens the younger, sons of Constantijn Huygens the elder, both obsessed with optics and renowned for their skill in making their own lenses, ordered lenses from Johan de Wyck, a Delft lens manufacturer.) Whenever Leeuwenhoek crossed the Market Square, he would have passed displays of lenses glittering in the sun like diamonds.
The fascination with lenses pervaded society. Many inhabitants of the Dutch Republic and elsewhere wished to produce their own; some became “almost fanatical in their devotion” to this undertaking, as a biographer of Descartes described his subject’s good friend Claude Mydorge. Mydorge, a mathematician, spent so much time studying optics and making lenses as well as mirrors that he completely neglected his family. Descartes himself was not only writing about optics while he was living in the Dutch Republic; he was grinding lenses and even trying to invent a lens-grinding machine. Over in England, enough people were grinding and using lenses that, even by 1658, the political thinker James Harrington could assert that Oxford scholars were “good at two things, at diminishing a Commonwealth and at Multiplying a Louse!”
Not much had changed in the method of making lenses since the sixteenth century. The new group of artisans that arose to take advantage of the desire for optical devices—instrument makers—were using the same techniques used by spectacle makers since the 1590s. Almost always, glass blanks (flat, round pieces cut from sheets of glass) made by the glass manufacturers were shaped by hand in metal forms, usually made of iron, sometimes of brass, and occasionally of a hard, nonporous wood. The metal forms, or “laps,” were at first simply pounded out and shaped by hammers, but later began to be molded on lathes similar to those used by clockmakers or jewelers. The lap would have the shape of the curvature desired for the finished lens; the precision of the curve would be tested, both when the lap was first made and then periodically afterward, by pressing a gauge with the correct curvature to the lap and holding both up to the window to see whether a sliver of light showed between them (in which case the curvature of the lap needed adjusting, by further carving or pounding out or by the addition of some material). The glass blank would be shaped, or “ground,” to fit the lap by the use of successively finer types of abrasive powders: tripoli, a dustlike silica; emery, a grayish black mixture of corundum and magnetite; and plain old sand, such as that used by the Dutch housewife to scour her floors. The final stage would usually involve the use of felt—a thick disk of felt would be glued to the lap, and the finest polishing agent would be applied to the lens while it rested on top of the felt. Alternatively, this combination of lap, felt, lens, and polish could be turned on a jeweler’s polishing wheel, once these instruments were modified for the lens-making craft.
However, although the techniques for grinding lenses did not change over the century, and were essentially the same for anyone grinding lenses, the quality of lenses produced by various lens makers varied greatly. Starting from an excellent glass blank was essential; indeed, the main difficulty in making good lenses out of ground glass at the time was that there were many imperfections in seventeenth- and eighteenth-century glass; it tended to be colored with greenish tints and marred by tiny bubbles, spots, and streaks. The best glass was found in Holland and England, and also sometimes in Italy, while Parisian glass was considered to be terrible, filled with bubbles and even visible black particles. Slight imperfections did not greatly affect lenses used for spectacles, but for instruments such as telescopes and, especially, microscopes, they could be ruinous. Tiny particles, bubbles, spots, and streaks could confuse the observer, leading him to see structures or shapes that were not really there, but were only artifacts of the imperfections in the glass. The polishing stages could add numerous minuscule irregularities on the surface of the lens, each of which could cause disturbing refractions and reflections. As little as a single large grain of abrasive could ruin everything: if it ended up in the mix being used in one of the later phases of grinding, it could scar the surface of the glass—and then excessive polishing to fix such scratches would distort the shape of the lens. The lens maker would check his lens for flaws by holding it up to strong sunlight in such a way that light reflected off the surface; nicks or breaks in the reflection would indicate imperfections in the lens. Sometimes the lens maker would find a rippled effect as the light passed through the polished lens, a result of a lack of homogeneity in the glass he had used. In 1616 Galileo’s student Giovanfrancesco Sagredo, charged with procuring lenses for Galileo’s telescopes, noted that he had examined three hundred lenses made by one of the best artisans in Venice; he deemed only twenty-two of them worthy of further testing, a mere
three of them passed those tests, and none was perfect.
Two other methods for making lenses were used in the seventeenth century, each with its own problems. In his Magia naturalis (1589) Della Porta had informed his readers, “In Germany there are made glass-balls, whose diameter is a Rhineland foot long [31.39 centimeters or 1.3 feet]. The ball is marked with an emerald-stone round and so is cut into many small circles.” Glass was blown into a sphere, and sections of that sphere were cut into the shape of a circle; each circle would already be curved, and would require merely finishing in the lap. (Early watch crystals were made in this way, too, but did not require as much finishing.) This method was plagued by the same problems facing the ground lenses, especially those imperfections introduced at the polishing stage.*4
Another possible technique for creating microscope lenses was making glass beads, or “spherules,” by drawing out a very thin thread of glass over a flame and cutting off the end when it had become a tiny bubble; sometimes the ends were just held over the flame until the glass melted into droplets, which fell onto a flat surface, where they would cool and harden. These glass beads could then be ground in the lap to form small, powerful lenses with very short focal lengths but high magnification. Although the beads suffered sooty stains from the flames and a greater susceptibility to bubbling, they magnified to such a degree that Kircher’s disciple Gaspar Schott would enthuse that in the smallest visible things, the smallest invisible things could be seen. Such glass beads were used in microscopes from at least the 1640s. In 1644 Odierna described using a crystal globule not larger than a chickpea. The same year, Galileo’s former student Evangelista Torricelli (who had recently invented the barometer) was reportedly making and using glass spherules as well. Soon afterward one of Torricelli’s patrons, Cardinal Gian Carlo de’ Medici, presented Kircher with glass globules no larger than the smallest pearls. Kircher used a small tube with one of these tiny beads at the end to examine the leg of a flea and was astonished by what he saw.
Eye of the Beholder: Johannes Vermeer, Antoni van Leeuwenhoek, and the Reinvention of Seeing Page 12