GLASS ------------------------------------------------------------------------ _Reprinted June, 1918._ _Reprinted June, 1919._ ------------------------------------------------------------------------ [Illustration: 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