6oo THE POPULAR SCIENCE MONTHLY. 



and curious forms, a considerable fame before the days of the 

 Roman supremacy; but the magnificent sheet of glass through 

 which we of a morning study the signs of the weather, or glance 

 at the too tempting displays in the shop-windows, is a luxury 

 which we must admit to be peculiar to our own times. It might 

 gain for us the title of the " age of glass," had not the age already 

 been devoted successively to the genius of iron, of steel, and of 

 electricity. 



There is also observable a marked difference in the spirit in 

 which the earlier and the later artisans worked. While glass was 

 still a product of some rarity, its manufacture naturally occupied 

 a place among the fine arts rather than among the more common 

 industries. The early glass-makers, in consequence, busied them- 

 selves more with the production of the costly and the beautiful 

 than in any attempt to bring glass in its manifold applications 

 within the reach of the poor. Later workers, on the other hand, 

 have shown the influence of democratic institutions. They have 

 found their greatest pleasure, as well as their greatest profit, in 

 the production of wares of such utility and cheapness that their 

 market includes even the very poorest. As a result of this en- 

 larged production, the history of glass shows a marked increase 

 in quality and a marked decrease in price. The interest aroused 

 by this progress is not only technical and commercial, but, in the 

 case of window-glass, in a still wider sense social and economic. 

 In filling the windows of our houses with transparency, the glass- 

 maker has been a public benefactor. His benefaction is the 

 greater, since the material he supplies is now at the disposal of 

 even those of limited means. We hardly appreciate the full sig- 

 nificance of cheap window-glass. It lengthens the day to the 

 dimensions assigned by Nature, and permits one to enjoy the 

 sunshine of out-door life without exposure to the inclemencies of 

 the weather. These are substantial contributions to the public 

 health and well-being. At no previous time, we believe, could 

 the dwellers in northern climes introduce into their homes so 

 many square feet of sunlight for so little money. 



It is the purpose of the present article to offer a brief glimpse 

 of some of the processes involved in the metamorphosis of the 

 crude materials into a serviceable pane of glass. As the opera- 

 tions are actually carried out in the arts, the attention of the on- 

 looker is constantly distracted by the flame and glare of the 

 furnaces, the passing and repassing of red-hot glass, the clouds of 

 steam, and puffs of dust and smoke. He comes away from the 

 factory with an impression limited to the more spectacular feat- 

 ures of the process. Of necessity he is quite oblivious of a 

 hundred details of which it is very necessary that the glass-maker 

 should be distinctly sensible. In making this visit by deputy, it 



