it was the next morning while mr. cabot and giusippe were still discussing the blaschka glass flowers that the italian lad remarked:

"i have wondered and wondered ever since we went out to harvard how those fragile flower models were annealed without breaking. it must have been very difficult."

"what is annealing?" inquired jean, holding at arm's length a doll's hat and straightening a feather at one side of it.

"annealing? why, the gradual cooling of the glass after it has been heated."

"what do they heat it for?"

"don't you know how glass is made?" giusippe asked in surprise.

jean shook her head.

"no. how should i?"

"why—but i thought every one knew that!"

"i don't see why. how could a girl know about the work you men do unless you take the trouble to tell her?" jean dimpled. "all through europe you and uncle bob have talked glass, glass, glass—nothing but glass, and as you both seemed to understand what you were talking about i did not like to interrupt and ask questions; but i had no more idea than the man in the moon what you meant sometimes."

"do you mean to say you know nothing at all about the process of glass-making, jean?" asked mr. cabot.

"not a thing."

"well, well, well! you have been a very patient little lady, that is all i can say. giusippe and i have been both rude and remiss, haven't we, giusippe? i thought of course you understood; and yet it is not at all strange that you did not. as you say, how could you? why didn't you ask us, dear?"

"oh, i didn't like to. i hate to seem stupid and be a bother."

"you are neither of those things, dear child. is she, giusippe?"

"i should say not."

"well then, if it is all the same to you, i do wish somebody would tell me whether glass is dug up out of the earth or is made of things mixed together like a pudding," said jean.

both giusippe and uncle bob laughed.

"the pudding idea is the nearer correct. glass is made from ingredients which are mixed together, boiled, baked, and set away to cool. isn't that about it, giusippe?"

giusippe nodded.

"i think the best remedy we can administer to this young lady, as well as the most fitting penance for our own discourtesy to her, is to escort her through a glass factory and let her, with her own eyes, behold the process. what do you say, giusippe?"

"a capital idea, señor. then i, too, should have the chance to visit an american factory and compare the process you use here with our italian method. i should like it above everything else."

"that is precisely what we will do then," declared mr. cabot. "on my first leisure day we will go, and in the meantime i will hunt up the location of the most satisfactory and nearest glass works."

not more than a week passed before uncle bob fulfilled his promise.

"make yourselves ready, oh ye glass-makers," said he one morning at breakfast. "i find after telephoning to the office that i am not needed to-day; therefore, the moment we have swallowed these estimable griddle cakes of hannah's we will hie us forth to instruct jean in the art of manufacturing vases, bottles, tumblers and the various sorts of glassware."

the two young people greeted the suggestion with pleasure.

"can you really get away to-day, uncle bob?" cried jean. "what fun we'll have!"

"i think it will be fun. we must, however, make giusippe captain of the expedition for he is the one who really knows glass-making from beginning to end, and can answer all our questions."

"i think i might in murano," returned the venetian modestly, "but that is no sign that i can do it here; your process may differ from the one we use at home."

"oh, i do not believe so—at least, not in essentials," mr. cabot answered.

so they started out, and before they had proceeded any distance at all they got into a spirited debate over the tiny lights of glass set in the top of the electric car. the panes were of ground glass dotted with an all-over pattern of small stars which had been left transparent.

"how did they make the stars on that glass?" was jean's innocent question. "did they scratch off the thick surface and leave the design of clear glass?"

"no indeed," mr. cabot replied. "on the contrary they started with the stars and then made the background cloudy."

"but i don't see how they could."

"do you, giusippe?"

"i am afraid not, señor."

"good! at last there is one fact about glass-making that i can impart to you. this sort of glass is known as sand-blast glass, and the art of making it, they say, chanced to be discovered near the seashore. it was found that when the strong winds rose and blew the sand against glass window-panes of the houses the small particles, being sharp, cut into the glass surface, and before long wore it to a cloudy white through which it was impossible to see out. often the glass fronts of lighthouses were injured in this way and the lights dimmed. finally some man came along who said: 'see here! why not turn this grinding effect of the sand to some purpose? why not apply it to transparent glass and make it frosted so one can get light but not see through it? often such glass would be a convenience.' therefore this inventor set his brain to the task. strong currents or streams of sand were directed against a clear glass surface with such force that they cut and ground it until it was no longer transparent. they called the product thus made sand-blast glass. later they improved upon it by laying a stencil over it so that a desired design was covered and remained protected from the sand blast. the result was a pattern such as you see—clear figures set in a background of clouded glass."

"how interesting!"

"yes, isn't it? as is true of so many other of our most clever inventions nature first showed man the path. ground glass in its modified forms is used for many purposes now; and yet i venture to say few persons know how it came to be discovered."

just at this point the car stopped with a sudden jerk, and beckoning jean and giusippe to follow, mr. cabot got out and entered a large brick building that stood close at hand. evidently he was expected, for a man came forward to greet him.

"mr. cabot?" he asked.

"yes. i received your note this morning, so i brought my young charges out at once. it is very good of you to allow us to go through the factory."

"we are always glad to see visitors. i will put you in the hands of one of our foremen who will take you about and tell you everything you may want to know."

he touched a bell.

"show mr. cabot and his friends down-stairs," said he to the boy who answered his call, "and introduce them to mr. wyman. tell him he is to conduct them over the works."

mr. wyman welcomed them cordially.

"we see many visitors here, sir," said he, "and are always glad to have them come. although glass-making is an old story to us scarce a day passes that some one does not visit us to whom the process is entirely new; and it certainly is interesting if a person has never seen it. suppose we begin at the very beginning. in this bin, or trough, you will see the mixture or batch of which the glass is made. it is composed of red lead and the finest of white beach sand. the lead is what gives the inside of the trough its vermilion color. the sand comes from abroad, and before it can be used it must be sifted and sifted through a series of closely woven cloths until it is smooth and fine as powder. before we put the mixture into the melting pots we heat it to a given temperature so that it will be less likely to chill the clay pots and break them."

"do you really make glass by melting up that stuff?" asked jean incredulously.

the man smiled.

"but isn't it all red?"

"the red comes out in the melting. we have to be very careful, however, in weighing out the ingredients, for much of our success depends on the accurate proportions of the materials combined in the batch. of course the chemical composition differs some for different sorts of glass. it all depends on what kind of glass is to be made. then too the conditions of the furnaces vary at times, the draughts being better at some seasons than at others. we take a test or proof of every fresh melt, and you would be surprised to see how little these differ. careful mixing of the raw materials is the first important item of successful glass-making; the second is the fusion by heat of the materials."

"the batch is next melted, jean," explained giusippe, as they followed mr. wyman into the great brick-paved room where the furnaces were.

here indeed was a picturesque scene. numberless men were hurrying hither and thither, some whirling in the air glowing masses of molten glass; others standing before the furnace doors gathering balls of it on the end of long iron blow-pipes which were from six to nine feet in length. everybody was scurrying. as soon as a ball of red-hot glass had been collected on the end of a blow-pipe it was rushed off to the blower before it cooled. in and out of the throng of moving workmen young boys, or carriers, swung along bearing to the annealing ovens on charred wooden trays or forks newly completed vases or pitchers.

jean glanced about, fascinated by the bustling crowd.

"here are the furnaces," the foreman said. "each one has twelve openings and is built with a low dome to keep in the heat. the flues or chimneys are in the sides of the furnace. within, and just beneath the openings or working-holes, stand the great clay pots of molten batch. these pots are made for us from new jersey clay; formerly we used to make them ourselves, but it was a great deal of trouble, and we now find it simpler to buy them. they vary in cost from thirty to seventy-five dollars, according to their size."

"and they are liable to break the first time they are used," whispered giusippe in a jesting undertone.

mr. wyman caught his words.

"ah, you know something of glass-making then, my young man?"

"a little."

"the pots are, as you say, a great lottery. sometimes one will be in constant use three months or longer, and do good service; on the other hand a pot may break the first time using and let all the melt into the furnace. then we have a lively time, i can tell you, ladling it out, and taking care in the meantime that none of the other pots are upset."

giusippe nodded appreciatively.

many a day just such a catastrophe had occurred when he had been working; vividly he recalled how all the men had been forced to come to the rescue.

"are the pots filled to the top with batch?" asked mr. cabot.

"yes, we charge them pretty solid; but the raw material loses bulk in melting, so they have to be filled in as the melt settles. at the end of ten or twelve hours we have a refilling or topping out, as we call it; usually this is enough. the first fill must become fluid and its gases must escape before any more material is added; we also have to be sure when we put the pots in the furnace that the temperature is high enough to melt the batch immediately, or the glass will go bad."

"what do you use for fuel?"

"crude oil. in the west they can get natural gas, and there they often melt the batch in tanks instead of pots. but we find crude oil quite satisfactory. you can readily understand that we cannot burn any fuel that gives off a waste product such as coal dust or cinders, because if we did such matter would get into the melt and speck the glass, causing it to be imperfect. much of the work done by the earliest glass-makers was specked in this way, and in fact the genuineness of old glass is sometimes determined from these very imperfections."

"i see," mr. cabot nodded.

"after the melt is in a fluid state it throws to the top, provided the heat is sufficient, many impurities such as bubbles and scum. these are, of course, skimmed off—a process called plaining. afterward the hot material has to be cooled before it can be worked, and reduced from fluid to a thicker consistency. this we call standing off or fining."

"how long does it take to melt the batch and get it ready to use?"

"about three days. we run a relay of furnaces—three of them—and plan so that a melt will be ready to be worked every other day; in that way we keep plenty of usable material on hand."

"and then?"

"then we are ready to go ahead and blow it. we make nothing but the better grades of blown glass here; that is, no window glass or cheap pressed ware. of course there are some patterns, such as fluted designs and their like, which cannot be entirely fashioned by the blower; therefore these are first blown as nearly the required size as possible and are then made into the desired form by shutting them inside iron moulds and squeezing them into the proper shape. you shall see it done later on."

he now led them up to where a gatherer stood at one of the working-holes of the furnace.

"this man," explained mr. wyman, "is collecting on his blow-pipe enough glass to make a pitcher. he uses his judgment as to the amount necessary, but so often has he estimated it that he seldom gets either too much or too little. he will next carry it to the blower, who will blow it into a long, pear-shaped cylinder the size he wants the pitcher to be."

they followed, and with much interest watched a great swede fill his lungs and blow into the smaller end of the iron pipe with all his strength; immediately the ball of soft, red-hot glass began to take form. with incredible speed the blower flattened its base upon a marver or table topped with sheet iron. a short iron rod or pontil was next fastened to the middle of the bottom of the pitcher in order that the blower might hold it, and after this had been done the blow-pipe was detached. the glass-maker sat in a sort of backless chair which had long, flat, metal-covered arms at either side, and as he worked he rolled the rod with its plastic material back and forth along one of these iron arms to shape it. he then took his shears and, making an incision at the middle of the back of the jug, he began to cut the top into the shape he wanted it, depending entirely on his eye for the outline. then quick as a flash he seized a bit of round metal not unlike a beet in shape and, pressing it inside the soft glass, made the depression for the nose. all this was done in much less time than it takes to tell it. a small boy, or carrier, now bobbed up at just the proper moment and taking the pitcher on his wooden fork carried it off to a small furnace where it was reheated at the opening or "glory hole." this little furnace, mr. wyman said, was used only for the purpose of softening glass objects which became chilled in the modeling and began to be hard and less pliable. as soon as the boy brought the pitcher back another lad, as if calculating by magic the precise moment at which to appear, approached with a small mass of molten glass at the end of his gathering-iron. this he stuck firmly against the pitcher at the correct spot to form the base of the handle; the modeler snipped off with his shears as much of the soft glass as he thought necessary, turned it up, and in the twinkling of an eye fastened the upper end of the handle in place. then he surveyed his handiwork an instant to make sure that it was symmetrical, straightened it just a shade with his battledore of charred wood, and passed it over to the carrier, who bore it off to be baked.

"why do they use so much charred wood for the shaping?" inquired jean.

"metal things are liable to mark the glass, leaving upon it a print, scratch, or other imperfection; charred wood, when worn down, is absolutely smooth and cannot mar the material."

"oh, yes, i see. and where have they taken the pitcher now?"

"we will follow it," replied the foreman.

escorting them across the room he showed them a low oven or kiln. the door of it was open, and inside they could see all sorts of glassware which had just been finished.

"here is where your pitcher will remain for the next three days," said he. "we build a fire, put the completed glass in the oven, and leave it there until the fire goes out and the oven gradually cools; we call the process annealing. it prevents the glass from breaking when exposed to friction or to the atmosphere. glass is very brittle, and extremely sensitive to heat and cold. if it were not annealed it would not be strong, and would snap to pieces the moment it came in contact with the outer air. now it is very difficult to anneal glass, the trouble being that all hollow ware is one temperature on the inside and another on the outside. hence, when heated, the inside takes longer to cool. any current of cold air that strikes it will fracture it. so, as you can readily see, an annealing kiln or oven must be arranged in such a way that it will allow the two surfaces to cool simultaneously."

"i think i understand," answered jean. "and you say these things must stay in the kiln about three days?"

"yes, the kiln takes about that time. it is a slow process, because we have practically no way of regulating its heat. a lehr does the work much quicker. over here you will see one. it is a long arch or oven open at both ends. the glassware travels in iron pans along a moving surface from the hot oven, or receiving end, to the cool, or discharging end. the temperature of the lehr can be scientifically tested and regulated, and this is very necessary, because the heavy glass intended for cutting can stand a greater heat than can ordinary hollow ware such as vials and table glass. we regulate the oven according to what we are annealing in it. it does not take so long to anneal glass in a lehr as in a kiln, and therefore in many factories only lehrs are used. if you will come around to the cool end you can see some of the finished pieces being taken out. each object is made by a certain set or gang of workmen—a shop, we call it. the work of each shop when taken from the lehr is put in a box by itself and is then counted up, and the men paid according to the number of perfect objects finished. it is piece work. for instance, one shop makes only pitchers, another wine-glasses, another vases, and so on. every group has its specialty, and each workman in the team understands exactly what his part is in the whole. the common interest of turning out as many perfect pieces as possible spurs each man to work as rapidly, well, and helpfully as he can."

"just like a football squad, uncle bob," laughed jean.

"exactly," nodded mr. wyman. "after the finished glass is taken from the kiln or lehr it goes to the examining room, where girls dip it in clear water and hold it to the light to test it for imperfections; then it is sorted, packed, and shipped."

"and vases, sugar-bowls, tumblers, and most of the hollow glassware is made in the same way?" inquired mr. cabot.

"yes, practically so. the general scheme is the same. as i told you, there are some difficult designs which must be squeezed into shape in moulds. these are of iron, and for the convenience of the blowers are set in holes in the floor. they are made in two parts joined by a hinge. the molten glass is blown to the approximate size and then a boy shuts it inside the mould and the blower blows into it until it has entirely filled out the mould in which it is confined. when released it is shaped to the form required."

"but doesn't it stick to the mould?"

"seldom. the moulds are painted over on the inside with a preparation which prevents the glass from sticking."

"do you cut any glass here?"

"oh, yes. cut glass is made from the heavier crystal variety. the design is roughly outlined upon it in white and then the cutter places the part to be cut against an emery-wheel, which grinds out the grooves and figures and makes the pattern. just above each cutter's revolving wheel is suspended a funnel of wet sand, and this drops at intervals upon the turning disc and cools it; otherwise it would become so hot from the friction that it could not be used. after the design has been cut on the emery-wheel all its rough edges are smoothed off on a stone of much finer grain. i can show you our glass cutters at work if you would care to see them."

"oh, do let's see them, uncle bob," begged jean.

"all right; but only for a few moments. we have already taken too much of mr. wyman's time, i fear. and besides, i must be back in town for luncheon," answered mr. cabot.

accordingly they went on into the next room, where jean became so fascinated by the whirring wheels and the men whose steady hands guided them that it was with difficulty she could be persuaded to leave and start for home.

"do you think, little lady, that when you get back to boston you can mix up some glass for us and bake it in hannah's oven?" questioned uncle bob of her when they were at last in the car.

"i am not sure," replied the girl with a bright smile. "but certainly i have a much clearer idea how to do it than i had before i went out to the factory. in future when you and giusippe talk glass-making i can at least be a bit more intelligent. i think, too, i appreciate now how wonderful it was that the egyptians, persians, and syrians discovered in those far-off days how to make glass. i am not at all sure, giusippe, that when we go to pittsburgh i shall not steal your trade and apply to uncle tom for a place in his factory."

mr. cabot pinched her cheek playfully.

"i guess you'd better stick to dressing dolls," he said.