Project Gutenberg's Glass and Glass Manufacture, by Percival Marson This eBook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org. If you are not located in the United States, you'll have to check the laws of the country where you are located before using this ebook. Title: Glass and Glass Manufacture Author: Percival Marson Release Date: October 9, 2020 [EBook #63421] Language: English Character set encoding: UTF-8 *** START OF THIS PROJECT GUTENBERG EBOOK GLASS AND GLASS MANUFACTURE *** Produced by deaurider, Barry Abrahamsen, and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) GLASS Reprinted June, 1918. Reprinted June, 1919. AN OLD GLASS HOUSE, A.D. 1790 Frontispiece PITMAN’S COMMON COMMODITIES AND INDUSTRIES GLASS AND GLASS MANUFACTURE BY PERCIVAL MARSON CONSULTANT UPON REFRACTORY MATERIALS, ETC., HONOURS AND MEDALLIST IN GLASS MANUFACTURE. LONDON SIR ISAAC PITMAN & SONS, LTD., 1 AMEN CORNER, E.C.4 BATH, MELBOURNE AND NEW YORK Printed by Sir Isaac Pitman & Sons, Ltd., London, Bath, New York and Melbourne PREFACE Who is not acquainted with glassware in some form or other? From the early days of the Ancient Egyptians the art of glassmaking was known, and it is now one of our most important industries, supplying as it does many articles for our common domestic use and convenience. Glass windows have introduced comfort and convenience into every home; for by their means light is admitted into our dwellings without the wind, rain and cold, and we enjoy the blessings of the one without the inconveniences of the others. The purposes for which glass can be used are manifold; and in domestic articles it contributes largely to our cleanliness and health. In the use of spectacles, table glass, mirrors, bottles, and many other goods our dependence upon glass becomes very evident. The degree of proficiency attained in the manufacture of glass is still more remarkable when we consider the various kinds of glassware used in physical, chemical, astronomic, medical, and other scientific investigations. Many of the wonderful results of the present times would not have been attained without the aid of glass in supplying the needs of our scientific investigators. Before August, 1914, few people realised the important part glass occupies in the production of war munitions. The importance of optical glasses for telescopes, gun sights, and microscopes is well known. Again, glass plays an essential part in every ship, locomotive, motor-car, aeroplane, and coal mine, and if defective glasses were supplied there would be a great loss in our industrial efficiency. The manufacture of high explosives or special steels could not be carried on without the supplies of laboratory glassware to enable the chemist to carry out his delicate tests. Upon the outbreak of the present war our supplies of certain types of glassware were not made in Great Britain, but imported from abroad, and it was owing to the energy and enterprise of a Scottish glass manufacturer, with some assistance from a well-known scientist, that a start was made in making these much-needed goods, and what might have been a serious crisis was averted. Professor Herbert Jackson and the Institute of Chemistry placed at the disposal of glass manufacturers numerous formulas for the special glasses that were urgently required, and later on this work was recognised by the Government; and now the investigations are being continued by a committee, with the assistance of the Government, under the control of the Ministry of Munitions. This committee is now rendering the greatest assistance to manufacturers in the general development of the glass trade and the reclamation of the ground lost in previous years. There is now every hope that Britain may raise again to eminence and perfection this very important industry of glassmaking. One of the chief objects of this volume is to supply within a small practical treatise the general available information upon glass manufacture, much of which, although familiar to many manufacturers or those engaged in glass works, will be of great assistance to those who are commencing a study of this very interesting and complex subject. Few people have any idea of the vast and enormous trade done on the Continent in the manufacture of glassware for export to Great Britain and British Possessions abroad, and on this account it is essential that so important a subject as glass manufacture should form some part in the technical education of our universities and trade schools, so that a section of the rising generation may be taught to understand the manufacture of such a necessary commercial product, and assist in recapturing the trade from the Continental glass works in supplying our needs. That some progress has been made along these lines is evident by the establishment at Sheffield University of a school in Glass Technology, and it is to be hoped that similar schools will be established in other centres, staffed by capable instructors and supported by the co-operation of the glass manufacturers. The author gives in an Appendix the literature accessible to those who wish for further information upon the subject, and trusts that, in the presentation of these notes, in response to the demand for such a book, a useful purpose will have been served by introducing the first principles of glass manufacture to those interested. It affords me great pleasure to acknowledge the valuable aid that has been rendered me by Mr. S. N. Jenkinson, Professor Herbert Jackson, and Mr. Frederick Carder, to whom I am much indebted. My thanks are also due to the following firms: Messrs. Melin & Co., Crutched Friars; The Hermansen Engineering Co., Birmingham; The Glass Engineering Co., Edinburgh; and Banks & Co., Edinburgh, who have kindly supplied me with illustrations. PERCIVAL MARSON. Craigentinny, Edinburgh. v vi vii CONTENTS CHAP. PAGE PREFACE V I. HISTORY 1 II. THE CHEMISTRY OF GLASS-MAKING AND THE MATERIALS USED 4 III. THE CHEMICAL AND PHYSICAL PROPERTIES OF GLASS 15 IV. THE COMPOSITION OF THE DIFFERENT KINDS OF GLASS 24 V. COLOURED GLASS AND ARTIFICIAL GEMS 28 VI. DECOLORIZERS 32 VII. THE REFRACTORY MATERIALS USED 36 VIII. GLASS HOUSE FURNACES 43 IX. GLASS-MELTING POTS AND THEIR MANUFACTURE 59 X. LEHRS AND ANNEALING 71 XI. THE MANIPULATION OF GLASS—GLASSMAKERS’ TOOLS AND MACHINES 76 XII. CROWN, SHEET, AND PLATE GLASS 89 XIII. TUBE, CANE, AND CHEMICAL GLASSWARE 96 XIV. OPTICAL GLASS 104 XV. DECORATIVE GLASSWARE 108 XVI. ENGLISH AND FOREIGN METHODS OF GLASS MANUFACTURE COMPARED 118 APPENDIX 123 INDEX 125 ix x LIST OF ILLUSTRATIONS PAGE AN OLD ENGLISH GLASS HOUSE, A.D. 1790 Frontispiece HORIZONTAL CRACKING-OFF MACHINE 1 INTERIOR VIEW OF AN ENGLISH GLASS-MELTING FURNACE 44 EXTERIOR VIEW OF AN ENGLISH GLASS-MELTING FURNACE 46 SIEMENS SIEGBERT REGENERATIVE GLASS-MELTING FURNACE— FIG. A. CROSS SECTION 48 FIG. B. SECTIONAL PLAN 49 Fig. C. SECTIONAL ELEVATION 50 A MODERN GLASS HOUSE. HERMANSEN’S CONTINUOUS RECUPERATIVE GLASS-MELTING FURNACE, COVERED POT TYPE 52 HERMANSEN’S CONTINUOUS RECUPERATIVE GLASS- MELTING FURNACE, 8-POT TYPE 53 HERMANSEN FURNACE— FIG. A. SECTION THROUGH GAS PRODUCER 54 FIG. B. CROSS SECTION THROUGH GAS PRODUCER 55 FIG. SECTIONAL PLAN 56 “THE HARLINGTON” BOTTLE-MAKING MACHINE 79 GLASS WORKER’S CHAIR 81 GLASSWARE BLOWN IN MOULDS, FIG. A. AND B. 85 VERTICAL CRACKING-OFF MACHINE 87 FOUR STAGES IN CROWN GLASS MAKING (A, B, C, D) 90 SIX STAGES IN SHEET GLASS MAKING (A, B, C, D, E, F) 91 MACHINE FOR SMOOTHING BOTTOMS OF TUMBLERS 110 GLASS ENGRAVING 113 xi GLASS AND GLASS MANUFACTURE 1 CHAPTER I HISTORY The discovery of making glass is attributed to the early Phoenicians. Pliny relates that certain mariners who had a cargo of soda salt, having landed on the banks of a river in Palestine, started a fire to cook their food, and, not finding any stones to rest their pots on, they placed under them some lumps of the soda from their cargo. They found that the heat of their fire had melted the soda and fused it with the sand of the river bank, producing a transparent glass. The natives in the vicinity where this discovery was made in process of time carried on the practice of fusing sand with soda and other materials to make glass, until they succeeded in improving and bringing the art to a high degree of excellence. Discoveries amongst the ruins of Pompeii and Herculaneum present some first-rate examples of the skill attained by the ancients in glassmaking: glass was found to have been used there, admitting light into dwellings in the form of window glass. The ancient Egyptians have left us many distinct proofs that glassmaking was practised in Egypt. At the same time, the glazing of pottery was also carried out, proving that they knew the mode of mixing, fusing, and melting the proper ingredients for glassmaking. Among the tombs of Thebes many specimens of glass and glazed pottery beads have been found, which suggests a date about 3,500 years ago. From the Egyptians, the Greeks and Romans acquired the art of glassmaking, which in Nero’s time was so highly developed that clear crystal glasses were produced in the form of drinking cups and goblets, which superseded the use of gold cups and were much prized by the Emperor in those days. Many specimens of old Roman glass discovered have been preserved in the British Museum, and, although many valuable pieces have been lost by disintegration and collapse due to the influence of years of exposure, there still remain some very fine examples which show that the Romans were highly skilled in glassmaking. One of the finest examples of the work of the ancient Romans in glassmaking is the Portland Vase, which was unearthed near Rome. This is an ornamented vase showing white opaque figures upon a dark blue background. The white opal appears to have been originally cased all over the blue and the beautiful figures carved out in cameo fashion, with astonishing patience and skill upon the part of the operator. The Venetians and Muranians followed the Romans in the art, and examples of old Venetian glassware show rare skill and ingenuity. To the Venetians belongs the honour of first making glass at a cost to allow of its being more generally used, and they also introduced the art of making window glass and drinking vessels into this country. Jacob Verzelina, a Venetian, introduced such glassmaking into England, working at a factory in Crutched Friars, London, between 1550 and 1557, where he made window glass, afterwards carrying on similar work in other places about the country until his death in 1606. Not until 1619 were glass works started in the neighbourhood of Stourbridge. There we find some remains of a factory worked by Tyzack about that date in making window glass in the village of Oldswinford. That Stourbridge should have been selected as one of the early centres for glassmaking is probably due to the presence in that locality of the so necessary and important to glass manufacturers in building their furnaces and pots, and the coal used for maintaining the fires for melting their glass. Stourbridge was known for a long time before this as a centre for the mines producing , and eventually this clay was adopted for making glass-house pots; now many other sources are available for these fire-clays. Much of the antiquity of the glassmaking of England is hidden in the neighbourhood of Stourbridge, and the writer has himself found a few antique specimens of old green devitrified window glass embedded in the subsoil of some fields near Oldswinford, probably relics of the Huguenots, who practised and extended the art of glassmaking in that district. Other important centres for glassmaking now are York, London, Manchester, Edinburgh, Newcastle, and Birmingham; but, although glassmaking has reached a high degree of excellence in this country, there is nothing yet comparable with the extensive factories which exist abroad. The conservatism of many English manufacturers, and the adverse influence of the Glass Makers’ Society, considerably restrict the progress of this trade compared with the broad and progressive manner in which it is carried on abroad.[1] 1. See article “Trade Unionism,” in last chapter. 2 3