Ear on Chicago; Glass Blowing

That sound you're hearing is that of a glass -blowing lathe. This lathe is located at the physical science department, Glashop, at the University of Chicago. The supervisor of this glass shop is Mr. Christian Van Hespin. We are going to do the story today of this glass shop and the glass that will be coming in here in just a few moments in glass blowing. Mr. Van Hespin, first of all, I want you to tell me a little bit about the operation that is taking place at this very moment. What is this man doing here? Mr. Hill, this man is making a doyer for our low temperature laboratory. A doyer is a double wall vessel from which the air is going to be evacuated and therefore can hold low -liquid at low temperatures. This man here is an expert on this lathe, I assume, what's his name? Oh yes, I would say so. His name is Mr. Geiss Cleo, and he's had several years of experience in doing this type of work. Guy, could you, while he has turned it off, I was just going to ask you to turn it off for just a moment so I could talk to you.

Can you turn it off in the middle of this operation? I can turn this off at any time as long as I don't set my fires off. I'm going to shut it off now. Okay, there she is. What does he want to know about that? Let me first of all describe what is taking place here. I'm sure that most people listening in, especially men who have woodworking shops or have seen woodworking shops, are familiar with what a lay is. And that's exactly what this piece of equipment is, except that it is the cutting instrument, is a series of gas jets, and the gas jets are now lit up the same as on a stove, a cooking stove. These glass jets point at the center of this long tube of glass. Now, instead of cutting, actually what you're doing is bringing it together, isn't that right, Guy? That's right, sir. It's quite a big diameter, and that's the purpose of having a glass laid, is to handle it with the machine rather than by

hand. It would be quite awkward to do it by hand, and it would take a lot longer, and a lot harder also. Now, would you tell me, Guy, just how this comes about? Does the glass actually melt? The glass actually goes to a liquid form almost. Glass actually is a liquid substance, and by applying a tremendous amount of heat, we liquefy it, and we can do anything we want with the glass once it's molten. Now, Guy, a little while ago, before you started to work with the lay, you told us there were some preliminaries that you would have to go through. What are they? Well, there's the lining of the glass in the chucks, and you tighten the chucks around the glass, and then you have to center the two pieces that you want to seal together, and you do that by just tapping it till it's center, and then you bring the two pieces together toward the fire, and then you're ready to go to work. All right, thanks, a million, Guy. It looks like you're about finished with the operation, are you? Just about all I have to

do now is anneal it with my annealing torch. Which I'm going to do now. Well, let's watch as you do it. Another gas jet, this one a bright blue flame. The purpose of this annealing torch is to take the strain out of the glass, so it won't crack before we put it in the oven. If we didn't anneal it, or I would crack in no time. So we'll always anneal all our work. Very interesting operation, a long tube of glass. Originally was in two parts joined together, and then melted together by the roll of gas jets with flames coming out of them. And now the annealing torch is putting the torch of blue flame against the glass, and when the flame strikes the glass it immediately becomes a bright orange. The annealing process is just about completed. You can hear that flame, I'm sure.

We've bring the cooling temperatures down. We cut down on the oxygen, and we have now just a half oxygen and half flame, half gas. I notice that the color of the flame has changed from a blue to a white. It's a half yellow, sort of, and half blue. And now I'm going to cut down the oxygen altogether, so we now have a yellow flame. I am now through and ready to shut the fires off. All right, guys, thank you very much. Now, Mr. Van Hespin, you have this long tube of glass here. What's the next process in making this piece of glass instrument that you said you had to make for one of your laboratories? Well, the next job would be to find a tube which would slide into this big tube we have just finished. Then we would seal the two ends of the tubes together,

making a do -our seal, and then we would anneal the apparatus. And annealing is taking the strain out of the glass. Now, when you saw a guy heating that glass, you set up a tremendous strain in that glass, which has to come out by heating up to a certain temperature, what we call the annealing temperature, and then slowly cooling. What he was doing was preliminary annealing from here on when the jar is finished, that will go into an annealing oven, which is an electrically heated oven, which goes up to about 1 ,050 degrees Fahrenheit. And then the temperature is gradually lowered, so that all the strain is taken out of the glass. And it will not easily break through thermal shock. Is this one of the typical jobs that you do for the university? Yes, one of the many hundreds of jobs that we do for the University of Chicago, yes. Well, now tell us something about glass blowing. That certainly is one of the passing arts of

our time, is it not? Yes, well, in a way it is. Machines, of course, are taking over a lot of the blowing. But this type of glass blowing that we do here, I don't think we'll ever die out, because it has so many different shapes and angles, which would be difficult to do on a machine. We're going to see some glass blowing after a while. Yes, I would be very happy to show you a little bit more other pieces of glass blowing, yes. And when the glass comes in, will they have some glass blowing that we can look at? Yes, they will. Of course, it's a glass I teach consisting of ten lessons, and the purpose of the glass is not so much to make glass blows out of those boys and girls, but to make them familiar with the glass. In other words, they must not be afraid of glass, because that will cause accidents. And it gives them a familiarity with the glass, and therefore they can handle their chemistry experiments more easy and more

without breaking. Mr. Van Haspen, tell us something about your background, and after that I'd like to take a brief tour of your lab so that you can point out some of the things that are done here. Yes. But tell us something about your background. I understand that you've been in this business for a long time. Yes, about thirty -five years. I started at a school in Holland, a low -temperature laboratory, and the Professor Carmeling -Hannes. He was a man who wanted to train his own men so that he could have all the glass blowing in the different types of glass apparatus he wanted. And so I was there for five years, graduated from there, and then I went to England, Oxford University. There I was for five years, and worked under Professor Lindemann. Then I came over to the United States in 1930. Right away I started work doing a lot of work for the World's Fair in 1933, making scientific apparatus for the Hall of Science. And it's also so happy that I did some ornamental glass blowing in the Belgian village. At the World's Fair?

That's right. It's a long time ago. Well, that's very interesting. Now, how long have you been here at the university? I haven't here 27 years. 27 years. It's a long time, yes. Well, let's take a look at your lab if you don't mind, Mr. Van Haspen. First of all, I might describe it. It's not a very large room as laboratories go. You might expect to find a much larger room. However, I think there is another room across the hall, is that true? That's right. That's where we keep our glass supplies and also teach the course in glass blowing, I mentioned before. Now, at each table, they have one, two tables on either side and a smaller table in the center. And at different places at the table are, again, these gas jets. What kind of burners do you call these? These are glass burners. And I would like to point out this particular one. This was made by one of my former men. He was a very bright man in glass blowing as well as developing things. He develops, for instance, this torch. And it is really two blow torches in one. And with the aid of two

cleverly devised valves, he was able to operate the valve, the burner with his feet. I can see they have two pedals down here that look like pedals on a pipe organ. That's right, yes. You can push these, I suppose, and control it. One controls the gas. Well, you go ahead and do it. One controls the oxygen. He's sitting down at a chair now and pushing the pedals. This is the gas. Now, and this is the oxygen, comes on now. Now, by simply pressing further on the pedals, we can increase the flame, thus flame. And again, bring it back to a very small, pinpoint flame. Well, you can just about get any flame you want to. That's right, yes. That's what's so nice about these torches. Well, now this torch, of course, is used for melting the glass, is it? Yes, that's right. It's not a piece of glass here. It's not melting the glass. Not

exactly melting. Melting is more making it in a fluid state. And we are softening the glass. Well, Mr. Van Hesseman is taking his glasses off and putting on a pair of blue -titted glasses. Why do you do that? Right. The sodium in the glass gives off an orange color flame. And that orange color, foggy color of flame obscures our vision. The glasses I am wearing now are called Diedemium glasses. And they have the property of absorbing that yellow form. That is formed by the sodium in the glass. This is going to hurt my eyes to watch it. Yes, no worries. It does not. You will see the yellow fog. I do not see it through my glasses. It's completely absorbed. So now I saw some of the glass and by simply rotating and pulling, I can separate a piece from my tube like

this. And I have a section now with which I can work and make an apparatus out of it. That was an extremely interesting, very minor job, I am sure, but something that probably has done a basic, a very basic preliminary operation of glass lawyers. Mr. Van Hesseman had a tube about an inch in a diameter. Is it an inch? An inch and a half. An inch and a half in diameter. I continue to say melt, perhaps that is not the right word. Mr. Van Hesseman says soften. He softened the center part of that long, inch and a half diameter glass tube. And all of a sudden he just sort of pulled on either end and it stretched out like a piece of rubber. And then he put it in the flame again, the small portion this time, and cracked it right in half. And is it true that no matter how long or how far you take that glass and stretch it, that there will always be a little hole in the center? That is right. That is right. You could pull it for miles

and still have a very tiny capillary in the center. What do you have here in your hand now? Well, I have a multiple seal in my hand here. It is a piece of metal to which a piece of glass is sealed. And a piece of uranium is then sealed to the ordinary glass. Through the uranium I, we have sealed eight tungsten wires. We use uranium glass here because the coefficient of expansion of the uranium is so much like the tungsten. In fact, it is more like the tungsten than the regular Pyrex glass is. That looks something like a radio tube. That is right. Basically, it could be used as a radio tube, but we use it for other purposes, of course. Okay, are you going to do something with it at this moment? No, this is finished. This is finished. I just wanted to show this to you. All right, now let me take a look over here on this other table. Here are a large number of glass pieces of glass, some tubes. And I suppose this is something that you are

working on for the school. That is right. These are all orders that we have to make up for the various departments. Well, are these glass tubes used in each of the scientific laboratories you have out here? Chemistry, physics, and so on? Yes, that is right. Nuclear studies instead of metals. And also the medical department on the university uses quite a bit of a glassware here. And the other table over there, we won't have to walk over that far, but it is very similar to the table we are standing in front of. It also has a large number of glass tubes, and again, those glass jets. And I think they can be controlled by the pedal system, too. We have five torches of the design that I described a little while ago. Mr. Van Hespin has come over to another piece of equipment now. The sound you are hearing is that of a drill. Actually, it has

a brass rod sticking out of it, which is split in the middle, and the brass rod is rotating. It is stuck then inside of a glass tube with some sort of an abrasive on it, and is grinding that glass. What is this, Mr. Van Hespin? The abrasive we are using is carbranum, a coarse carbranum, and is used to grind the inside of the glass tube. What is this machine called? This is an horizontal grinder. Now, what is the purpose for grinding that glass on the inside like that? To make it smooth for one thing, and also so that we will be able to fit another piece of glass in here, tight fitting. Because this piece of apparatus is to be used for grinding tissue in the surgical department. Do you mean animal tissue? Animal and human tissue. Cancer tissue or whatever they want to pulverize. And with that, of course, they proceed with their experiments and examinations of tissue.

Is that right? Yes, that's right. I can use that under the microscope after they grind it. They could, that's right. Yes. Now, why do you have these tubes in water like you have? Well, we have to use water as a lubricant for the carbranum. If we use the carbranum dry, it would freeze or what we call stick. And we would get a grinding of rings in the glass. In other words, it's a lubricant. I notice when the glass is ground, there's a fog which forms on the inside of it. Is that just merely ground glass in there that we're looking at? That's right. The glass is a section of the glass cut away by the carbranum and leave an opaque surface. Well, go right ahead with your job. I didn't want to interrupt too much, but I didn't want to hear about it. Once again, he's putting that glass tube on that brass rod that is rotating and the abrasive is cutting away at the glass on the inside of the tube. That sound you heard was the sound of a saw, a

glass saw. It just cut through a piece of inch and a half glass tubing. Mr. Van Hespin, what is that disc made out of to cut the glass the way it does? The disc is made of carbranum and it's pressed at a very thin shape in order to cut more easy through the glass. What's this gentleman's name operating this piece of equipment? It's Mr. Leonard Coutula and he is one of my glass blowers and a very able man indeed. Leonard, what's the purpose for the saw? Well, the purpose of cutting glass, as we can see, well, it's used for grinding. If we have some surfaces that have to be ground or squared, we generally use this saw also. Of course, cut the pieces of glass to fit the size and dimension that you need. Is that right? That's right. At times, glass may have to be cut diagonally or different angles and so forth and what we use to solve for that purpose also. Just this one you're cutting at a 90 -degree angle. That's right. That's what we had just finished now cutting at a 90 -degree angle. You can cut it at

a 45 -degree angle? That's possible, yes. Well, suppose you do that for us and we'll watch it. Do you have to readjust the equipment? That's right. The adjustment has to be made in order to do this. Well, just cut it at a 90 -degree angle. That's all right. This is not an experiment, is it? No, purposes of this broadcast. But the object is the same in cutting through. It's just that you have to set the machine at the desired angle in order to get your cut. To create any heat, I notice there's a lot of water there. I suppose that's for cooling. That's right. That's what the water is used for. That thing goes through that glass like a piece of butter is cut by a hot knife. That's right. It does. Of course, it's quite messy. We have another way of cutting glass. But this is one method of doing it. Mr. Van Haspin, what is glass made of? By

glass is mainly made of silica or sand. Then it is mixed with soda and potash and various metal oxides in order to give it clarity and durability. If we heat the shock, for instance, and also to give it color. Now, what about... We've seen a lot of glass tubing, but there's a... Well, what do you call this thing that I have in my hand? I just picked it up. You just picked up a 500cc boiling flask made of Pyrex glass. Now, how do you make a flask like this out of a tube? Well, for one thing, we would not make it because we buy these flasks. We only make the pieces of apparatus that cannot be bought. These flasks are commercially made and we make them into other pieces of apparatus. Well, I see you buy this flask for your own purposes, right? That's the sound of a gas jet

in the class where the students have gathered just a few moments ago to begin their Friday afternoon session. There are seven students here. Actually, the class has eight. There is one student missing today. And they have a project on which they're working. Mr. Van Haspin, what's the assignment for today? Well, today we are making an ordinary T -piece. It consists of a three -inch length tube piece of tubing in which we blow a small hole, like, for instance, like puncturing a tire tube. We seal a side arm onto it in the flame and thereby making a connection between three tubes. A little while ago I saw you demonstrating to the class the experiment that they were going to work on. Where is that little T -piece that you had so that we can look at it and describe what it actually is? Well, we've made it into a cross now. We started with a T -piece and then sealed an outer tube on the other side of the side arm, thus making a cross piece. This is also very useful with chemical

apparatus. What Mr. Van Haspin did was simply to take a small glass tube, stretch it out, and then blow a hole in the side of it. And after the hole was blown on the side of it, attach another tube to it, is that right? That's right, so yes. Now this tube attached to the side of it, of course, would make the T, and then he simply blew a hole on the other side of it, attached another tube to make the cross. What would this be used for? Well, it would be very handy if you had four pieces of rubber tubing which you would want to connect together. We have four outlets and four rubber tubes, make an perfect connection. Oh, yes, I see. Well, they would use that, I would imagine, quite often in a chemistry lab, for example. Quite so, yes. Mr. Van Haspin, do they do any ornamental glass blowing in here? No, we are only concerned with simple scientific glass apparatus. The students here, of course, they do not become glass blowers. The main purpose for this course is to give them a feeling for a glass.

Also, of course, they learn to repair certain simple pieces of glass apparatus when they leave here. You say they acquaint themselves with glass so that they can handle glass? Is it sometimes difficult to handle these tubes and things like that? Yes, when they come to the university or to any class, it seems that while people are afraid of glass and thereby have accidents. By getting acquainted with the glass in this course, they know how to handle it and avoid accidents that way. That has been proven. Mr. Van Haspin, how did this glass blowing begin? Well, it really began accidentally, I imagine. We do not have much history. There is not much in history about this beginning of glass blowing. But stories are that glass was blown 3500 years BC. Now, there is some controversy about it. Other

people say that it is not so. It is a picture of another type of work, not glass. Glass blowing. You mean you have a picture of this operation, 3500 BC? Somebody painted it? There was a relief cut out in stone of two men with a pot of glass, what we thought was glass in between them and blowing through a pipe. Other people will claim that it is simply a two men working on some metal work. How do you think they first discovered how to blow it that you could actually stretch glass? Well, I really do not know, but I imagine that by handling glass and just pulling it, somebody might accidentally have blown or closed off a bubble of gas in the glass and that expanded while it was being heated and thus giving the idea of forcing air in the glass by mouth and then blowing it that way. Now, a little while ago, when we were describing how you were stretching the glass, we

said that it was melting and you said the word to use is soften. That is right. Can you actually melt glass? Well, I would say glass ornaments, dishes and so forth, the glass is in molten state in the big vets, but it is not at the temperature that we use in our laboratory here. And that is at a much lower temperature? And you only soften it so that you can work with it? That's right, yes. But in factories it is actually liquid. How does glass get that facility that you can soften it and stretch it that way? Well, from heating, of course. No, I know the heating, but I mean what is the chemical change? Are the chemical change in the silicon or whatever holds the glass together? Well, glass is made up of silica, of course. The main part is silica with the soda and part ash and metal oxides to give it coloring. And by raising the temperature, I suppose that the chemical

reaction takes place and softens it, flows together. Mr. Van Hespin, we would like to be able to take a look at some of the ornamental glass blowing. However, as you said, to have stated throughout the program that the operation in this department here is not for ornaments, but for making glass equipment for laboratories so that we won't be able to see the ornament blowing or talk about it, but at least you can tell us a little bit about how you do it. You're an expert in ornament work, aren't you? Well, not exactly an expert, Mr. Hill. I do it for, in my own free time, I make a few little things. Also, the other man in my shop, they are quite good at making little faces, perfume bottles, and that sort of thing. But we really do not go in for large ornamental stuff. Is the glass blowing industry a good place for a man to begin his life's work? Well, yes and no, it all depends

on the type of person you have in mind. It takes a training of about five to six years to really become a good glass blowing. And training nowadays is rather frowned upon by young men, so I would think not. The apprenticeship is too much for them nowadays. That's right, sir. How long did you serve as an apprentice? I served five years as an apprentice. But we have an apprentice here in our shop, and I was rather fortunate to get him. He is a serious young man, and he felt that he'd rather have a training than to start with high pay. Well, now there is a shortage of glassblowers in the country today, aren't there? Yes, there is. Although most universities are training their own glassblowers from chemists and instrument makers to do glassblowing on the side. Well, Mr. Van Hespin, it's been a pleasure to come out here and visit your department. We want to thank you very much for allowing us to come in and interrupt your class somewhat and take your time to discuss with us this very interesting operation of glassblowing.

Okay, Mr. Hill, you're very welcome and to come again. That's the story of the physical science department glass shop at the University of Chicago. We have been talking to Mr. Christian Van Hespin, the supervisor, and this is Hill Hill speaking.