CHAPTER XVI

ENGLISH AND FOREIGN METHODS OF GLASS MANUFACTURE COMPARED

The continental methods of glassmaking differ so much from the English methods that a few remarks giving comparisons will be of interest. It is noticeable that chemical and engineering science is more thoroughly applied in the manufacture of glassware abroad. Their method of specialising wherever possible, and the introduction of mechanical and automatic machines have done much toward increasing their production and efficiency.

The flourishing and extensive state of glassmaking abroad is shown by the size and extent of the glass works, some of which work as many as forty or fifty furnaces and employ 3,000 to 5,000 hands. Gas-fired regenerative or recuperative furnaces are more generally used, which permit higher temperatures, cheaper metal, and greater economy in fuel and labour.

The present type of English furnace is very wasteful, and even with good fuel it is difficult to maintain high temperatures and regularity in working. Our method of firing, raking, and teasing is very exhausting to the workmen in attendance.

In many English glass works, especially those in the Stourbridge district, it is the practice to fill the pots on a Saturday morning and take until the following Monday night to melt and plain the glass, no glassware being made for three days of each week. Starting on Monday night or Tuesday morning, the glass makers work in six hour shifts day and night until Friday night or Saturday morning, when the pots are again filled and the weekly course starts over again. Abroad the pots are filled nightly and hold just sufficient metal to last out the work during the day, and are built of a capacity to suit the articles being made. The disadvantages of our method are obvious when a comparison is made with the continental method of melting the glass nightly and working it out daily, especially when the efficiency or output of the furnaces as compared with their fuel consumption is taken into consideration.

Abroad the furnaces are small and compact; they take up less floor space, yet they are far greater in efficiency. As they are gas-fired, the combustion is more complete, and by the use of regenerators or recuperators greater heat is available for melting the glass quickly. Larger proportions of sand are used in the glass mixtures, which, being the cheaper component, cheapen the production of their glass wares.

Owing to the more perfect combustion which takes place within the chambers of gas-fired furnaces abroad, lead glasses are successfully melted within open crucible pots. When the heat comes into direct contact with the batch materials being melted, it does its work quicker and with less fuel consumption than is the case if it has first to be conducted through the hood of covered pots which have necessarily to be used in the old English type of furnace.

It is particularly noticeable that the glass workers abroad do not spend so much time upon producing an article as is usual under the English method of working. By the extensive use of moulds fitted to mechanical contrivances operated by the foot, their work is expedited and made simple and easy.

Technological education in the glass industry abroad is more thorough and general. The glass workers, not having to work at night, have the evenings free for recreation and education. It would do much towards developing the English glass trade if night work for boys could be abolished. The adoption of the continental system of melting the metal during the night and working only during the day (by using gas-fired furnaces) would do much in this direction. One cannot expect the youths of the glass trade, who have to work during nights, to attend the evening classes for educating themselves, without a severe strain upon their constitutions. This fact partially accounts for the repeated failure to establish technical classes and trade schools in the glassmaking centres of this country. The conservatism and lack of support from the glass manufacturers themselves account for much of the slow progress and development of the trade. As a rule, it will be found that the manufacturers have everything to gain by the better technical education of their employees. It is with pleasure we notice that a few at least are now taking this broader view and giving such schools their hearty support and financial aid. In the glassmaking centres abroad there are established state-aided technical and trade schools, where, for a small nominal fee, the youths of the glass works are trained and taught the principles of their industry. Apprenticeship in the factories then becomes unnecessary.

The working hours abroad are usually sixty hours a week (ten hours a day), compared with the English forty-four to fifty hours’ week (six hour shifts).

The trade unions of the glass workers abroad are more progressive, and their officials do not interfere with the manufacturers’ endeavours to increase efficiency and cheapen production by introducing machinery. The promotion of the workpeople goes by merit, and not by the dictation of the trade union officials, as is too often the case in this country. Here, very little sentiment or good-fellowship exists between the glass workers’ union and the employers, and in its place the rank officialdom of unionism has become so evident as to be a bar to the progress of the industry. Instead of assisting the progress of the trade, and mediating in cases of dispute, the union appears to exist as a buffer of antagonism between the glass workers and their employers. Many a capable youth in the glass trade here has been kept back from promotion to a better position solely by the dictation of the union to which the men belong. Cases are known where the union have restricted the workman’s output when he may be working under piece rate. The best inducements may have been offered him by the employer to increase his output, and, although the workman may be willing to accept the master’s terms, we find a union official stepping between them, and fixing the maximum number of the articles that shall be made in his six hour shift. Usually, this fixed quantity is got through in four hours, yet the workman is not allowed to make more than the stipulated number fixed by the union, or he is fined. Another incredible fact is that the employer here, when in need of a workman, is not allowed to choose his own men. He must apply to the union, and the man remaining longest on the society’s unemployed book is then sent to him. Whatever his inefficiency may be, the employer is bound to take him; if he employs anyone else, a strike results. Such action is despotic and shows up the worst features of trade unionism that can possibly be conceived. The English glass industry has been repeatedly disorganised by this obstinate attitude of the glass makers’ union, and a consequence is that the foreigner has seized the opportunity to step in and increase his market, to the detriment of our own trade; with this extended market, increased output, and cheaper production, the foreigner undersells us in our own country.

It is to be hoped these adverse conditions will soon be remedied and the English glass industry restored to a more flourishing state by the prompt and united action of the men and masters, realising the gravity of the position and acting accordingly.

APPENDIX

JOURNALS AND BOOKS FOR REFERENCE

“American Pottery Gazette.” (New York, U.S.A.)

“Boswell’s Memoir on Sands Suitable for Glassmaking.” (Longmans, Green & Co., London.)

“Pottery Gazette.” (Scott Greenwood, London.)

“Sprechsaal.” (Coburg, Germany.)

“Painting on Glass and Porcelain.” Hermann. (Scott Greenwood.)

“Decorated Glass Processes.” (Constable, London.)

“Jena Glass.” Hovestadt. (Macmillan & Co.)

“Glass Manufacture.” Rosenhain.

“Producer Gas-Fired Furnaces.” Ostwald.

“Glassmaking.” By A. Pellatt. (Bogue, London.)

“Gas and Coal Dust Firing.” Putsch. (Scott Greenwood.)

“The Collected Writings of H. Seger.” (Scott Greenwood.)

“Ceramic Industries.” Vol. I. By Mellor.

“Modern Brickmaking”; “British Clays, Sands, and Shales”; “Handbook of Clay Working.” By A. B. Searle. (Griffin & Co.)

“Glass Blowing.” By Shenstone.

“Asch’s Silicates of Chemistry and Commerce.”

“Clays.” By A. B. Searle. (Pitman, London.)

“Fuel and Refractory Materials.” Sexton. (Mackie & Sons.)

“Furnaces and Refractories.” Harvard. (McGraw, New York)

SOCIETIES’ JOURNALS AND TRANSACTIONS

“The Society of Glass Technology.” (Sheffield.)

“The American Ceramic Society.” (Columbus, Ohio, U.S.A.)

“The English Ceramic Society.” (Stoke-on-Trent, Staffs.)

“Journal of the Society of Chemical Industry.” (Westminster, London.)

INDEX

Aberration, 104

Acids, action of, on glass, 18, 19

Action of glass on , 45

Alkali, 23

Alumina, 9-11, 20

Amethyst, 31

Analysis of , 37

Ancient glass, 1

Annealing glass, 18

—— pots, 66

Arsenic, 31

Artificial eyes, 101

—— cements, 24

—— pearls, 31

Aventurine, 22-102

Barytes, 8-26

Basalt, 10

Bastie’s Process of hardening glass, 18

Batch, 11-13

Beads, 31-116

Black glass, 29

Blowing glass, 80, 82

Blow-iron, 80

Blue glass, 28

Bohemian glass, 25

Borates in glass, 7, 8, 9

Boric acid, 7

Bottle glass, 26, 27

Bottle-making, 77, 79

Bull’s eye, 90

Buttons, 116

Cane, 97

Capacity of pots, 51-52

—— of tank furnace, 56

Carbonate of soda, 6

Cements, 24

Chain screen, 68

Chair, Glassmakers’, 81

Chemical properties of glass, 4-15

Chemical Formulae, 12

Chimneys, Lamp, 16

Clays for pots and furnaces, 36

Coloured glasses, 28, 29

Colour of silicates, 11-22

Complex glass, 26

Composition of glass, 4-25

Compound glasses, 25

Conductivity of glass, 23

Continental glass, 3, 88, 118

Covered pots, 21-27

Cracking-off glass, 15, 17, 85

Crown glass, 26-89

Crucible pots, 21, 27, 64

Cullet, 10, 85

Cutting glass, 8, 10, 16

Decay in glass, 2

Decomposition, 2, 19

Decorated glass, 108

Decolorants, 32

Defects, 9, 23, 34

De-grading glass, 23

Density, 16

Devitrification, 3, 8, 20

Discovery of glass, 1

Doll’s eyes, 101

Education, Technical, 120

Electric furnaces, 58

Emerald, 31

Enamelling glass, 115

English type of furnace, 43

Engraving glass, 111

Etching, 19-112

Expansion, Thermal, 16

Eye of furnace, 43

Eyes, Artificial, 101

Fancy glass, 116

Filigree, 99

Fire-clay, 3, 11-36

—— analyses, 37

Fire-clay, blocks, 39, 45

——, Burnt, 39, 41, 61

—— crucibles, 64

——, Grinding of, 39

——, Melting point of, 64

——, Mild, 39, 65

—— pots, 62

——, Properties of, 36-38, 41

—— rings, 65

——, Selection of 38

—— stoppers, 66

—— Strong, 39, 64

——, Tempering, 39, 61

——, Weathering, 39, 61

Flint glass, 4

—— stones, 4

Fluorspar, 8

Foot maker, 82

Formulas, 12, 21

Frisbie’s Feeder, 47

Furnaces, 21, 41, 51, 57

Fusibility of glass, 9

Gadget, 28

Garnet, 31

Gas-fired furnaces, 47, 51, 55

Gathering, 76, 77

Glass, Afterworkings of, 86

——, Alkalies in, 23

——, Alumina in, 9, 11, 20

——, Ancient, 2

——, Annealing, 71

——, Cane, 97

——, Coloured, 28

—— cloth, 101

——, Cut, 109

——, Enamelled, 115

——, Founding of, 69, 74

—— furnaces, 21, 41, 51, 56

——, Gauge, 18

——, Grinding of, 94

——, Hardened, 95

——, Homogeneity of, 23

—— house pots, 62

——, Moulds for, 77

——, Melting of, 69

——, Plasticity of hot, 4-16

——, Polishing of, 92-94

——, Properties of, 15

——, Process of making, 15, 76

——, Sand-blasted, 114

——, Scum on, 69

——, Seeds in, 105

——, Silvered, 116

—— snow, 101

——, Stress in, 74

——, Strengthened, 95

——, Temperature of melting, 20

——, Tube, 96

——, Types of, 15, 25

——, Wired, 95

—— wool, 101

——, Yellow, 28

Grinding tumblers, 110

—— plate glass, 92, 94

Hardened, 18, 23

Hermansen’s Furnace, 52, 53

History, 1

Homogeneity, 23

Honey pot making, 85

Hydrofluoric acid, 19

Introduction of glassmaking in England, 2

Iridescence, 21-101

Iron in glass, 32

Italian Aventurine, 102

Laboratory glass, 25

Ladling glass, 45

Lamp glass chimneys, 16

Lead glass, 21

—— poisoning, 14

Lehr, 71

Light and glass, 33

Lime glass, 25, 26

Machines in glassmaking, 79, 111

Mechanical boy, 86

Millefiore, 100

Moulds, 85

Opalescent glass, 95-109

Opal glass, 29, 31

Optical glass, 5, 9, 33, 104

Oxidising agents, 7

Pearl ash, 6

Pearls, 31, 116

Phosphates in glass, 8

Polariscope, 74

Potash, 6

—— glass, 24

Pots, 8-13, 27-58

——, Annealing, 66

—— cracking, 45, 69

—— clays, 37, 64

——, Glazing, 69

——, Making, 62

——, Open, 21, 27, 64

——, Plumbago, 65

——, rings, stoppers, 63-65, 66

—— sherds, 65

——, Setting, 67

——, Trolley, 46

Plaining glass, 4, 51, 69

Plasticity, 11, 16

Plate glass, 26, 93

Plumbago, 65

Pressed glass, 26, 77

Pucellas, 82

Quartz glass, 19

Réaumur’s Porcelain, 17

Recipes for glass making, 25, 26

Recuperative furnaces, 52-54

Reduction in glass, 28, 31

Regenerative furnaces, 49

Rocaille flux, 25

Roman glass, 2

Ruby glass, 28, 31

Rupert drops, 18

Saltpetre, 7

Sands, 4

Sand-blast, 114

Scratching glass, 16

Screens for pot setting, 68

Seeds in glass, 4, 13, 105

Servitor, 83

Shearing glass, 81, 83

Sheet glass, 91

Siemens Furnace, 48

Siege of furnace, 43, 44

Silica, 4, 5

Silicates in glass, 24

Silvering glass, 116

Simple glasses, 24

Soda-lime glass, 21-26

Soft glass, 5

Soluble glass, 24

Spun glass, 15, 100

Stirring glass, 105

Strengthened glass, 95

Stress in glass, 18, 104

Striae, 9

Sulphates, 5, 25

Table glass, 25, 76, 77

Tank glass, 26, 57

Technical Education in glass manufacture, 120

Temperature of furnaces, 20, 105

Thermal expansion of glass, 16

Tin oxide in glass, 10

Tizeur, 43, 46

Tools, 76

Topaz, 31

Trades Unionism, 86

Tube, 26, 98

Tumblers, 85, 110

Turquoise, 31

Uranium, 28

Varieties of glass, 25, 102

Venetian glass, 2

Violet glass, 28

Waste glass, 30

Waterglass, 24

Wine-glass making, 82

Window glass, 1

Wired glass, 95

Working hours, 120

Zinc oxide, 9

_Printed by Sir Isaac Pitman & Sons, Ltd., Bath, England_

● Transcriber’s Notes: ○ Missing or obscured punctuation was silently corrected. ○ Typographical errors were silently corrected. ○ Inconsistent spelling and hyphenation were made consistent only when a predominant form was found in this book. ○ Text that was in italics is enclosed by underscores (_italics_); text that was bold by “equal” signs (=bold=). ○ The use of a caret (^) before a letter, or letters, shows that the following letter or letters was intended to be a superscript, as in S^t Bartholomew or 10^{th} Century. ○ Superscripts are used to indicate numbers raised to a power. In this plain text document, they are represented by characters like this: “P^3” or “10^{18}”, _i.e._ P cubed or 10 to the 18th power. ○ Variables in formulae sometimes use subscripts, which look like this: “A_{0}”. This would be read “A sub 0”.

End of Project Gutenberg's Glass and Glass Manufacture, by Percival Marson