by Vince Beiser
This miraculous compound is mostly just melted sand; silica makes up as much as 70 percent of the volume of typical window glass. But not just any sand will do. A more refined breed of grain is required than the common construction sand used for concrete. Glass sand belongs to a category called industrial, or silica, sand. To make it into this club, the sand typically must be at least 95 percent pure silicon dioxide, and largely free of certain impurities. (The most common impurity in sand is iron, which imparts a green color; that’s why sheet glass seen from the side looks green.) The best silica sands also come relatively uniform in size. Grains that are too big won’t melt as easily, and ones that are too small will be blown away by air currents in the furnaces.
Befitting their nobler composition, industrial sands are much more expensive than those used for construction. Though America produces ten times more construction sand than industrial sand each year, the US Geological Survey estimates that the total value of the elite industrial grains is actually higher than that of their lower-grade cousin: $8.3 billion per year, versus $7.2 billion.
The sands chosen for glass have a fundamentally different mission than those used in concrete. Construction sand grains retain their form when made into concrete; they are cemented together with countless legions of their fellow grains and their big brothers, gravel pieces, perpetually working together. The grains that become glass, however, are actually transmuted, losing their individual bodies as they are fused together to form a completely different substance.
Getting them to do that, however, is not easy. It takes temperatures topping 1,600 degrees Celsius to melt silica grains. But mixing sand with additives known as flux, such as soda (aka sodium carbonate), lowers that melting point dramatically. Throw in a little calcium, in the form of powdered limestone or seashell fragments, melt it all together, and when the mixture cools, you have basic glass.5
Part of what makes glass so adaptable is that the silicon dioxide that forms it is sort of a solid that acts like a liquid. As materials scientist and engineer Mark Miodownik explains in Stuff Matters: Exploring the Marvelous Materials That Shape Our Man-Made World, a regular solid, like ice, can be melted into a liquid—water—and then frozen again, and each time its molecules will re-form into a crystal pattern. “With SiO2 things are different,” writes Miodownik. “When this liquid cools down, the SiO2 molecules find it very difficult to form a crystal again. It’s almost as if they can’t quite remember how to do it: which molecule goes where, who should be next to whom, appears to be a difficult problem for the SiO2 molecules. As the liquid gets cooler, the SiO2 molecules have less and less energy, reducing their ability to move around, which compounds the problem: it gets even harder for them to get to the right position in the crystal structure. The result is a solid material that has the molecular structure of a chaotic liquid: a glass.”6
No one knows how people first discovered this miraculous bit of alchemy, but we do know it happened a very long time ago. It was probably an accident, when someone made a fire on a beach where the sand contained some kind of flux that lowered its melting point—soda ash left over from burning certain plants, maybe, or seaweed. And it probably happened in more than one place. Glass beads have been found in modern-day Iraq, Syria, and the Caucasus dating back four thousand to five thousand years. Glass was a must-have ornamental item throughout the ancient world, showing up as glazing on pottery, in jewelry, and as small containers. Ancient Egypt in the time of Rameses the Great, around 1250 BCE, had a substantial glassworks that made perfume bottles and decorative items.
Writing some 3,000 years later, Dr. Samuel Johnson mused: “Who when he first saw the sand and ashes by a casual intenseness of heat melted into a metalline form, rugged with excrescences and clouded with impurities, would have imagined that in this shapeless lump lay concealed so many conveniences of life as would, in time, constitute a great part of the happiness of the world. . . . He was facilitating and prolonging the enjoyment of light, enlarging the avenues of science, and conferring the highest and most lasting pleasures; he was enabling the student to contemplate nature, and the beauty to behold herself.”7
The Romans, as usual, took the technology to the next level. They made great advances in understanding how to use flux, to the point where they were able to manufacture glass in relatively large quantities and export it all over the empire. They figured out that adding manganese oxide helped clarify the glass, which led to a new invention: semitransparent windows.8 And they refined techniques of glass blowing that produced the most delicate wineglasses the world had yet seen.
Glass caught on like Pokémon. Glasses so clear they let tipplers see the color of their wine came into permanent fashion across Europe. Windows that let in light but kept out rain and cold were a tremendous quality-of-life boost for people living in more northerly, inclement climates (at least those who could afford them). Artisans mastered the process of coloring glass panes and created the beautiful stained-glass windows that still dazzle visitors at the cathedrals of Chartres, York Minster, and many others.9
Glassmaking developed into such a profitable art in Venice that in 1291 the city-state’s rulers ordered all of the city’s glassmakers to move to the island of Murano. There they were treated like aristocrats—but not allowed to leave, lest they take their coveted craft secrets to rival nations. The sand for the Venetians’ famous tableware and decorative items was an exceptionally pure type they brought in from the Ticino River, which flows out of the Alps past Milan.10 Today’s Venetian artisans get their sand from France’s Fontainebleau region, which is upward of 98 percent pure silica. (Corning, an American company that is one of the world’s largest producers of glass and ceramics, also operates the world’s largest ophthalmic glass production center in Fontainebleau.)
Around the same time as the establishment of the artisan colony on Murano, the area around Valdelsa, in Tuscany,11 emerged as another important European glassmaking center. Glassmakers used the abundant local forests for fuel to melt sands from the Arno River and the beaches near Pisa. Unlike their Venetian counterparts, these artisans were free to emigrate, which many of them eventually did, spreading the glass trade across Europe. The Valdelsa region still provides some 15 percent of the world’s leaded glass crystal.
In the fifteenth century, Angelo Barovier, one of the Murano artisans and scion of a family of glassmakers, set about handpicking an elite selection of the purest sands he could find. He processed them carefully, and in time developed crystallo, the first truly colorless, transparent glass. This turned out to be a historic breakthrough.
Transparent glass not only made for much better windows; it also made possible high-quality lenses, those unassuming little disks that have essentially endowed us with superpowers. The lenses of microscopes and telescopes enable us to see pieces of the universe we didn’t even know existed, objects so tiny or so distant that our naked eyes could never perceive them. These innovations underpinned the scientific revolution.
Telescopes and microscopes were preceded by simpler magnifying lenses in the form of eyeglasses, another tremendously important augmenter of human perception. “The invention of spectacles increased the intellectual life of professional workers by fifteen years or more,” write Macfarlane and Martin. Eyeglasses likely abetted the surge of knowledge in Europe from the fourteenth century on. “Much of the later work of great writers such as Petrarch would not have been completed without spectacles. The active life of skilled craftsmen, often engaged in very detailed close work, was also almost doubled,” Macfarlane and Martin maintain. The ability to read into one’s old age became even more important once the printing press came into widespread use from the middle of the fifteenth century.12
It’s not clear who invented the first telescope. Amid growing demand for eyeglasses, many people around Europe were experimenting with lenses and mirrors by the late 1500s. The first unambiguous record is from 1608, when an anonymous young spectaclemake
r from the Dutch town of Middelburg offered an invention to the commander of the Dutch army: a tube containing two glass lenses, “by means of which all things at a very great distance can be seen as if they were nearby.”13 The army brass immediately recognized the device’s military potential. Within weeks at least three other Dutch inventors had applied for government patents on telescopes; none were granted, as so many people obviously knew the secret to making them. It’s no wonder there was so much optical experimentation in the Netherlands: Holland boasted a sophisticated glass industry, of which Middelburg was an important center, thanks in part to the local abundance of high-quality river sands.14
Telescopes—powerful tools for navigators, military commanders, and even artists painting landscapes—spread at an astonishing speed. By 1609 small spyglasses were being sold in shops in France, Germany, England, and Italy. That spring, an Italian scientist named Galileo Galilei heard about them and began making his own. Rapidly improving prototype after prototype, he soon had a device capable of magnifying images twentyfold. Staring up at the night sky through his creation, Galileo was able to perceive truths about the cosmos that changed history. Among many other discoveries, he determined that the earth revolves around the sun, not the other way around—a heretical notion at the time, one that got him placed under house arrest for much of his later life. Sand showed us our real position in the universe—our planet is just one speck among billions.
There is also controversy about who invented the first microscope, but the first crude version is often credited to a Dutch spectacle-maker named Zacharias Janssen, around 1590. Galileo also experimented with using sets of lenses for extreme magnification. Several versions of early microscopes could be found across Europe by the 1620s, but they were not at first used for scientific research. “The role of microscopes was limited mostly to the demonstration of wonders and curiosities of nature, and natural philosophers and the public delighted to see the known world magnified,” writes Laura J. Snyder in Eye of the Beholder, a history of lenses.15
That began to change rapidly in the 1650s, thanks largely to a young apprentice draper in the Dutch city of Delft named Antoni van Leeuwenhoek. Intrigued by the magnifying lenses his profession used to determine the thread counts of fabrics, Leeuwenhoek started experimenting with his own homemade microscopes. Of necessity, Leeuwenhoek—as well as Galileo and other scientists across Europe—became skilled glass grinders. They made their own lenses from plain glass “blanks,” which they shaped into lenses by grinding and polishing them with a variety of abrasives, including ordinary sand.16
Leeuwenhoek produced hundreds of microscopes and put them to use to discover red blood cells, bacteria, and sperm. He was also the first scientist to seriously investigate the different characteristics of individual sand grains17—using lenses made from sand and shaped with sand to examine sand.
Taken together, the introduction of optical instruments in science showed the world that “behind the phenomena we see with the naked eye is an unseen world, and in this invisible world lie the causes of the natural processes we observe,” writes Snyder.18 Lenses showed us “that the world is not—or not only—as it seems to be.”
While glass in many forms was spreading across Europe, the Asian powers of Japan and China didn’t pay much attention to this new material, though they knew about it. This must rank among one of history’s greatest oversights. Among other things, it meant that they had no microscopes, telescopes, or even eyeglasses until Western missionaries introduced them around 1551. That technological gap may help explain why Europe raced so far ahead of Asia in so many scientific fields in the seventeenth and eighteenth centuries.
In the United States, on the other hand, glassmaking was one of the very first industries that the early colonists established. Groups of Dutch, Polish, and Italian glassmakers19 set up shop in the first permanent British settlement at Jamestown, Virginia, in the early 1600s, making window glass, bowls, and beads for trade with native peoples. In 1739, the industry picked up significantly when a German immigrant named Caspar Wistar opened a glass factory near Salem, New Jersey, attracted by the plentiful trees to fuel furnaces, oyster shells to provide calcium, and abundant supplies of clean, high-purity quartz sand.20 Wistar’s factory produced handblown bottles, which were in ever greater demand among beer brewers in the New World. Thomas Jefferson himself had a sideline brewing beer at his Monticello estate in Virginia, where there was such a shortage of glass jugs that he had to order them from as far away as New York. At one point he even experimented with making glass himself.
European glass imports, however, dominated the American market until the mid-1800s, when the Civil War interrupted trade. At around the same time, Americans started finding major domestic sources of high-quality sand. From 1820 to 1880, the number of glass furnaces in the United States grew fivefold, while the number of people working in the industry multiplied twenty-five-fold.21
As the Industrial Revolution took hold across America, whole cities and regions grew up around the glass trade, just as they did around steel, coal, and other mushrooming industries. To manufacture glass profitably, glassmakers need easy access to high-quality sand, cheap energy to run the furnaces, and a transportation network to get the product to market. In the 1880s, the city fathers of a small, relatively young town in Ohio called Toledo realized they had all those resources and more. Eager to build up their settlement, they set about wooing glassmakers from the East to relocate. Toledo, they bragged in newspaper advertisements and personal meetings, had cheap land, cheap labor (including employable children as young as eight), natural gas, and a location on Lake Erie that offered access to canals, rivers, and railroads. Just as important, the city lay near a seam of extremely high-quality silica sand, so pure it was sold to glassmakers as far away as Pittsburgh and Wheeling.
The pitch worked. Glass manufacturers poured in. So many of them set up shop in Toledo—around a hundred by the turn of the twentieth century—that it became known as the Glass City. It remained a vital center of the trade for decades. “Toledo glass was used to make the spacesuits of the astronauts who landed on the moon in 1969, and it was used by Admiral Richard E. Byrd in scientific experiments he conducted at the South Pole in the 1930s,” notes Barbara Floyd in her history of Toledo, The Glass City: Toledo and the Industry That Built It. “It protected America’s Declaration of Independence in the National Archives, and it has been used by revolutionaries around the world to convey their beliefs with Molotov cocktails. It has held the punch served at receptions in the White House, and the alcohol in the brown bags of paupers on street corners everywhere. It insulated the Alaskan oil pipeline, and it is used in solar energy panels. It is displayed in some of the finest art museums in the world, and every day it is tossed into garbage pits.”22
Among the earliest transplants to Toledo was Edward D. Libbey, owner of a glass factory in East Cambridge, Massachusetts. Libbey’s business had been prospering, but his unionized workers were demanding higher wages. Moreover, his energy bills kept rising. Those once-vast forests of New England, a resource previously thought inexhaustible, were rapidly disappearing into industrial furnaces. So in 1888, just like an offshoring corporation today, Libbey moved his operation to a place where costs were lower. It was a fateful move for Libbey, for Toledo, and in fact for all of us.
Seeking skilled workers to staff his new factory, Libbey made a personal recruiting trip to the glass industry hub of Wheeling, West Virginia. He quickly signed up a full roster. He was just getting ready to leave his hotel room when Mike Owens, the former child coal miner, barged in. By then a beefy, square-faced, broad-nosed man of thirty, Owens announced that he was coming to Toledo to work for Libbey. This, at least, is the version Skrabec recounts in his somewhat hagiographic biography of Owens. “Libbey apologized, explaining that he had all the men he needed,” writes Skrabec. “Owens replied: ‘Oh, no, you don’t! You need me!’ and . . . the man’s appearance and sel
f-confidence just stopped him.”23
However the job interview actually went, Owens was hired. Hard-driving, ambitious, and extremely intelligent despite his near-total lack of schooling, he quickly worked his way up the ranks to become Libbey’s top lieutenant. As a manager, Owens was punctilious and demanding. He had a sunny smile and could be charming, but he also had a serious temper. He wasn’t averse to cussing out or literally kicking the ass of a malingering worker.
When Owens started at the Libbey Glass plant in 1889, the place was still making bottles much the same way it had been done in the West Virginia factory where he had started out as a boy—which wasn’t much different from the method used back in Jamestown.24 First, the mix of sand, soda ash, and other ingredients was placed in giant pots inside a furnace, where over the course of many hours it melted into a thick, taffy-like goop. Under the supervision of a master glassblower, or gaffer, a gatherer would stick a six-foot iron blowpipe into a pot, swirl up a glob of this infernally hot molten glass, then roll it into a ball on a metal table.
The gaffer, the most highly skilled member of the crew, then took the pipe and blew the mass into the desired shape, sometimes with the help of a cast-iron mold clamped around the molten glass. The glass might cool down during the blowing, requiring a stick boy to put it back into the furnace to soften it up again. Once the glass was in the right basic shape, the gaffer and his assistants would refine it with wooden tools, reheating as necessary. A carry-in boy would then take the still-hot finished piece to another furnace, where it would be gradually cooled and hardened, a process called annealing. A standard crew of five to eight men and boys working ten-hour shifts could produce about 3,600 bottles a day—about one per minute. Not exactly an efficient way to mass-manufacture a consumer product.