GLASS-MAKING. 



6ii 



which, these window-panes are destined to confront. Perhaps the 

 old fable of the wind and the sun comes back to him. The cloak 

 that the one in all its fury could not tear off is gladly thrown 

 aside when the other exerts its power. The same with our pane 

 of glass. It is to repel the rougher storms and winds, yielding 

 passage only to the gentler elements. Sunshine and moonlight 

 are to filter through it, and back of it pleasant fireside pictures 

 are to group themselves. But the imagination is not always so 

 obliging; darker possibilities obtrude themselves as well. The 

 shuddering forms of want and wretchedness are also there, and 

 the solitary dreamer is glad to turn away from them all, and pass 

 out of the open door back again into the world of reality. 



RoTABT Grinding Machine tor Platb Glass. 



The manufacture of crown glass possesses considerable histor- 

 ical interest, but little beyond that. Within the past few years it 

 has been brought into some prominence again from its growing 

 use in decorative windows. It possesses, it is true, a brilliancy 

 much superior to that of sheet glass, but the small size and un- 

 equal thickness of the pane obtainable do not permit it to com- 

 pete successfully with the generous dimensions and remarkable 

 uniformity of the glass now dominant. In mode of fabrication 

 the crown glass proceeds precisely as the sheet up to the time of 

 blowing; at this point the two processes diverge. The ball of 

 semi-plastic glass on the end of the blow-pipe is fashioned into the 

 shape of a cone, as the result of successive rollings on a table of 

 metal or stone, known as the " marver." The process itself goes 

 under the name of " marvering." The apex of the cone forms the 

 so-called "bullion-point." By blowing into the mouth-piece of 

 his pipe, the blower expands the glass into a small globe. This is 

 subsequently enlarged, care being taken that the bullion-point is 

 always kept in line with the pipe. The globe of glass is then 



