Demaine goes to the furnace to heat the piece up again and at this point, this malleable blob can be transformed into a cup or a bowl, a beaker or a flask, as they were made throughout history. He decides to make a cup and blows into the pipe again, expanding the bubble until it is more air than glass. After transferring the piece to another pipe, he opens up the glass bubble with a tool resembling oversized tweezers, all the while being careful to make sure that the walls don’t collapse, heating frequently so the piece doesn’t crack, because glass, like many things, requires constant attention. After careful manipulation, the glass has taken on the shape of a cup and Demaine knocks the piece off the rod to be slowly cooled down in an annealing kiln.

Barring Demaine’s protective eyewear, the natural gas used in the furnace (early furnaces used timber), and the people at the back of the MIT Glass Lab checking their smartphones, this scene could describe a glassblowing session that happened this year or five hundred years ago.

Despite this peaceful scene, glassblowing, including scientific glassblowing, was a dangerous line of work in the past, with workers losing appendages and frequently suffering from injuries as glass objects exploded or shattered during the heat working process. Severe burns were common, especially on the feet, when molten glass would drip off tools and burn through the shoes of the glassblowers.

“Accidents happened all the time…when glassmakers were making large cylinders for window glass they were standing high on the floor above deep pits where they would swing these long, long cylinders to elongate the glass…to be flattened out, and people fell into these pits and broke their arms,” says Gay Taylor, former curator of the Museum of American Glass.

Not only were their outer appendages put at risk, but their internal organs as well, with, “respiratory injuries too, breathing in the different kinds of things and of course all of the things associated with asbestos,” Taylor says.

Even though technological improvements in glass are constantly being made, glassblowing can still be relatively hazardous, and accidents can still happen. “It was a tedious and dangerous process to grind taper parts to make vacuum tight fittings. My dad lost all of his fingers on one hand due to such an accident,” says Mike Souza, resident glassblower at Princeton. Luckily, the grinding process has been made safer due to innovators at MIT.

But why would these men and women put themselves at bodily risk? In addition to having a passion for the craft, glassblowers have been responsible for the success or failure of a multitude of experimental designs, many working at their own peril to turn a scientist’s vision into reality. Though lead scientists often get most of the credit for their discoveries, the glassblowers assisting alongside them should not go unrecognized.

Because glass is so ubiquitous, it is easy to forget that it was once a precious commodity—a tool that scientists depended on, and still rely upon, to make revolutionary discoveries, with the material itself becoming an intrinsic part in some of the most important scientific breakthroughs.

“Glass helped to accelerate the amazing acquisition of knowledge about the natural and physical worlds by providing new scientific instruments: microscopes, telescopes, barometers, thermometers, vacuum flasks, retort flasks, and many others. Glass literally opened people’s eyes and minds to new possibilities and turned western civilization from an aural to a visual mode of interpreting experience,” writes Alan MacFarlane, emeritus professor in social anthropology at Cambridge University, in an article titled “A World of Glass,” published in Science. In the Collection of Historical Scientific Instruments at Harvard, it is estimated that at least forty percent of the items in the collection feature at least one glass component

The relationship between glassblowing and scientific progression in the past has paved the road for present-day scientific glassblowers, who are still vitally important as they work alongside researchers. The field is continuously becoming more dynamic and innovative, as scientists demand purer materials and intricate equipment that pushes the boundaries of research, just as it has been the case throughout history.

Glassblowing became more widespread in the 12th Century A.D. in Italy. It was such a lucrative and desirable practice that the unfortunate glassblowers of Venice were forced to relocate to Murano Island and produce their wares, both out of fear of their furnaces burning the city down and also because the Republic of Venice wanted to keep their glassblowing techniques a secret from competitors. Despite the fact that Murano was only about a fifteen minute boat ride from the city, these artisans and their families weren’t allowed to leave the island and the techniques of Murano were so well guarded that for much of European history, only Italian glassblowers knew how to create clear glass, known as cristallo.

Leeuwenhoek Microscope
Wikimedia Commons

In the 17th and 18th Century, during the period of Enlightenment, many of the classic scientific experiments required glass components to function, such as telescopes, electrostatic equipment and chemistry vessels. That is not to say, however, that the fabrication of some of these instruments was any less secretive than at Murano.

For example, Leeuwenhoek, the founder of microbiology, guarded the techniques he used in crafting microscope lenses so rigidly that Constatijn Huygens remarked, “What a brute!” after a failed attempt to probe Leeuwenhoek about his instruments. Working in secrecy, Leeuwenhoek perfected his microscope design and was the first person to see single-celled organisms and described many wonders found in the human body including sperm, muscle fibers, and bacteria.

Physics has had a long partnership with glassblowers, with various glass apparatuses used to identify gases, excite electrons and separate molecules. Ernest Rutherford, the father of nuclear physics, relied on glassblower Otto Baumbach, a man of incredible skill, to create alpha-ray tubes: tubes of glass with less than a one-twentieth-inch diameter, and walls so incredibly thin that alpha particles could pass through. Broken glass began to accumulate in Rutherford’s laboratory as a result of the fragility of the glass he was experimenting with. It was by using these delicate tubes that Rutherford was first able to hypothesize the existence of the nucleus in an atom.

Medicine is also indebted to creations made of glass. The perfusion pump, invented by Charles Lindbergh (the famous aviator) and Alexis Carrel in 1934, was designed using blown Pyrex glass. This perfusion pump was the first instrument to be able to keep organs alive outside of the body during surgery and was first used to successfully sustain a thyroid gland excised from a cat. The instrument worked by pumping oxygenated blood through the various tubes of the perfusion pump (playing the role of the lungs and the heart), delivering the blood to the organ. This invention was hailed as a medical breakthrough and was on the cover of Time magazine in 1938.

Working with such modern glass as borosilicate and quartz was impossible for most of history, as furnaces and torches were unable to deliver the heat needed to melt the glass. Glassblowers in the 1600s onward were forced to contend with “betty lamps,” which were pewter wick lamps that burned using animal fat. The glassblower would then have to focus the flame using bellows powered by foot pedals similar to a sewing machine’s. It was the use of these lamps that gave rise to the term “lampworking,” which remains in use today, despite the changes in technology.

Scientists experimenting with glass often lit candles and intensified the flame using a small blowpipe to blow air into the flame itself. Special breathing techniques were used to continuously keep the flame focused and steady while thin rods of glass were painstakingly melted down.

Tom Hession
Courtesy G. Finkenbeiner Inc.

Despite being deeply rooted in the past, the scientific glassblowing industry has undergone tremendous technological change.

G. Finkenbeiner Inc. in Waltham, Massachusetts, is a small scientific glass shop that sits along a road lined with old-style, Mom-and-Pop manufacturing companies. Many of these buildings lie empty, their redbrick facades crumbling, their windows cracked and greyed with layers of dust. Though the surrounding businesses have fallen on lean times, the inside of Finkenbeiner’s is lively and warm, the heat mostly exuding from the oxygen and hydrogen torch that Tom Hession is using to blow globes into a tube of quartz. In modern times, glassworkers such as Hession use torches fueled with oxygen and hydrogen or methane to create flames that reach 3,200° Celsius in order to melt these temperamental forms of glass. The globes will later be cut to perfection by Diane, his wife, whom he met working at the shop and now handles the business side of Finkenbeiner’s. His son also works there, learning the skill of glassblowing from his father, in true family-run business style.

Instead of soda lime glass, used by the Italian glassblowers in Murano, Hession works with borosilicate glass (also known as Pyrex) and quartz, which are now more commonly used for making modern scientific tools. Though, at 550° C, soda lime glass melts quicker than quartz (1,800° C) and borosilicate (1649°C) and is therefore easier to heat and mold, these modern glasses are more resistant to thermal shock and are less likely to shatter when exposed to heat during experimentation.

The atmosphere of the glass fabrication lab lies in stark contrast with the artistic lab at MIT. There are no traditional glassblowing furnaces here and the quartz and borosilicate comes in hollow tubes that Hession melts down and shapes with torches with electric blue flames that burn so brightly that he has to wear dark tinted glasses to work.

A back section of the space is sectioned off with plastic that reaches the ground and a garment resembling a HAZMAT suit hangs off the wall. This area is a clean room that Hession uses to finish quartz instruments that require extreme levels of cleanliness and purity, with the finished pieces being used in the manufacturing of computer chips.

The studio could be mistaken for a chemistry lab, with chemical hoods, industrial hardware tools, and various flasks, tubes and beakers sitting on tables, all in different states of disrepair. Finkenbeiner’s modifies mass-produced instruments for scientists and repairs broken equipment. The glass industry is a field in which it is sometimes cheaper to repair expensive instruments rather than replace them and the shop has boxes of mangled objects lined up, waiting patiently to be fixed.

Hession started working at the glass shop when he was only fifteen, first cleaning the floors and restocking the glass and then ultimately becoming an apprentice when he was seventeen. He and his wife now run the business after the original owner, the German-born Gerhard Finkenbeiner, mysteriously disappeared thirteen years ago. In a tale reminiscent of Amelia Earhart, Finkenbeiner decided to take a nighttime flight in his private airplane and disappeared. To this day, neither aircraft nor body has been found, though Diane Hession speculates he may have met his misfortune in the ocean.

His disappearance was mourned by everyone at the shop, especially by Hession since Finkenbeiner, as his wife says, “was like a father to him.” Eventually, they took over ownership of Finkenbeiner’s and have been successfully running the business every since.

Though the technology has advanced the field of glassblowing, scientists still depend on glass in much the same way. As it was in history, scientific glassworkers are still called in to design and create prototypes for cutting-edge experiments. “You can get to a prototype much faster in glass than any other material,” says Mike Souza.

There is still a level secrecy in the industry, since glassblowers are often asked to create instruments involved in patent filings and when they consult with researchers, they must be careful not to divulge exclusive, patented designs or procedures.

Physics and medicine still remain popular fields for employing glassblowers. Souza, for example, specializes in blowing aluminosilicate glass, which he uses to create glass cells. These are filled with helium 3 (which contain an unpaired neutron) and alkali metals, and then heated until they become a vapor. Because this type of glass is impermeable to helium, and resistant to alkali vapors, it is ideal for containing these gases for study. When shot with a laser, the alkali electrons become excited and collide with the neutrons from helium 3, creating a magnetized gas. This magnetized gas can be studied for its behavior. Additionally, these gases can be filled into human lungs during MRI scans, the magnetization of the atoms making it possible for the lungs to be imaged, something that was previously difficult to do because MRIs are not ideal for capturing open circulation organs.

Finkenbeiner’s creates aortic arch models, which are glass replicas of the aorta and connecting arteries. Heart surgeons are able to use these as teaching tools to demonstrate how to properly insert catheters, without having students waste practice hearts or endanger lives.

Though collaboration between scientists and glassblowers are necessary, glassblowers are still careful not to call themselves scientists. “As a scientific glassblower, we are not scientists…it’s [like] asking a piano maker to play a song,” says Shaun Conroy says, a glassblower who focuses on quartz instruments.

Aaron Kirchhoff, a glassworker for the National Institute for Standards and Technology, says, “I don’t call myself a scientific glassblower when people ask me what I do. If I don’t want to have a conversation…I tell them I’m a physical science technician…If I feel like I want to share stuff with them, I tell them I’m a glass fabrication specialist. That reflects…a lot of the really innovative stuff that we do that really doesn’t fall under glassblowing.“

Despite this distinction, as collaborations become closer, the line between scientists and glassblowers become blurred, with glassblowers such as Mike Souza becoming co-authors on academic papers and giving lectures on his work. Daryl Smith, resident glassblower at Yale, even teaches his own class, a basic scientific glassblowing course that shows scientists how to fix their own equipment and to understand the capabilities and limitations of glass and the glassblower. This understanding between scientists and glassblowers is key, because the process, as Smith says, “can be quite challenging because it is two different mindsets coming together and trying to come up with a design.”

Though these glassblowers are not labeled as scientists, many do consider themselves artists. Many point to their artistic background as the main reason they become interested in scientific glassblowing, citing financial stability and exciting research as two reasons why they have crossed over. Conroy says his main motivation for pursuing scientific glassblowing is, “the paycheck, really, to know that I could get paid, because as an artist it is a struggle.”

Though artistic and scientific glassblowing are considered two different disciplines, there is enormous overlap between the two practices, with people disagreeing as to which field has a bigger influence on which. “So many of these artists get their background in the scientific apparatus which then becomes their basic income so they can, in fact, branch out and do artistic work. They became classically trained, so that they knew all of the techniques…” says Gay Taylor.

Glass Harmonica

Although Shaun Conroy fabricates scientific instruments, he also makes glass harmonicas, a complicated musical invention created by Benjamin Franklin, which involves handblown quartz cups of descending size, fitting into one another almost like nesting eggs. The cups are connected to a mechanism that spins the cups, and the player wets and touches his fingers to the edge of the cups, creating a delicate, beautifully haunting sound. The rims of the cups are dipped into liquid gold during creation to add to the overall aesthetic effect.

Tom Hession, in addition to creating glass harmonicas, is also known for blowing elegant glass vases and sculptural pieces from the extra glass that is leftover from making or modifying scientific equipment.

There seems to be a general consensus that practicing both artistic and scientific glassblowing only helps to improve both areas of expertise. “It’s really my experience in the art realm that influences my industrial processes…there’s some very specific techniques that I have only ever seen in the art realm and I took it and applied it in this capacity and now it has made us able to make some of the glassware that makes us literally the only place in the world to have made them,” says Aaron Kirchhoff.

Though scientific glassblowing has perservered throughout the centuries, it is undeniable that, in the day and age of mass production, the demand for handmade glassware has diminished. The majority of glassblowers today work at companies like Chemglass, where the employees have limited interaction with the scientists who purchase their equipment. Even prestigious universities like Princeton, which originally had four glassblowers in employment, shrank its team down to only one person.

But although the number of job openings in research institutions and other private companies are fewer, the work that glassblowers are commissioned to make is not only increasingly interesting, but also crucial to the progression of science.

“We just kind of have an open-door policy and researchers just walk in and they’ll talk to us about theirs needs…and they are crazy ideas, they are absolutely things that are not made elsewhere because of the nature of remaining at the forefront of…technology, it means that generally speaking that none of the stuff have been made before, we are always forging new territory,” says Kirchhoff.

As scientific fields become narrower, glassblowers are also moving towards more specialization. Many glassworkers, especially those that collaborate closely with researchers, work on vastly different projects than their peers at any given time. “It’s not a cookie cutter type of thing,” says Shaun Conroy, describing the field.

With its long, rich history, it is easy to assume that glassblowing in an antiquated craft, destined to become obsolete. But glassblowing has advanced alongside science, and with hotter torches, modern tools, and new types of glass, the potential possibilities in glassblowing have never been more exciting.

Research is always progressing at a breakneck pace, with glassblowers continuing to implement modern technology in order to perfect their craft, but scientific glassblowing still pulls from history to create instruments.

Regarding the historical evolution of the practice, Mike Souza says, “I would say the fundamentals are basically the same. It is a material we can heat to soften and then while it is in this ‘plastic state’ we can inflate it, weld it, cut it with scissors, basically give it any form you can imagine and then carefully cool it back into a rigid solid. All of these techniques are basically unchanged.”