GLASS-MAKING. in 



America, Australia, and New Zealand. But wherever it 

 may come from and whatever may be its destiny, its past 

 history has been much the same in all cases. Falling, in 

 the first instance, from banks, cliffs, or mountain sides, it has 

 undergone much grinding and pounding in the bed either ot 

 glacier or river, and, after being washed, carefully sorted, and 

 carried no one knows how many miles, has at last reached 

 the resting-place, from which, after the lapse it may be of 

 ages, it has been taken to the glass-house, whence it emerges 

 in a totally changed form to begin a fresh career. 



For, from the common wine bottle, made 01 rough 

 sand and other coarse materials, on through the many 

 other varieties, till we come to the finest plate, crystal, and 

 Venetian glass ; from the common ill-shaped tumbler to the 

 exquisite ornaments fabricated by Salviati every kind owes 

 its existence, more or less, to the sand whose history we 

 have been tracing. 



But sand does not always remain sand until man happens 

 to find a use for it. At the mouth of many rivers it is fre- 

 quently found cemented into stone by the carbonate of lime 

 brought down by them, and all the sandstone used for build- 

 ing was once nothing but loose sand lying along the shore, 

 every grain of which has been more or less rounded by long- 

 continued washing. 



Some beds of sandstone are a thousand feet thick and 

 more, and were, to all appearance, accumulated in bygone 

 ages on an ancient shore which stretched from England 

 across the North of Germany. It is not easy to say how the 

 sand was consolidated, whether by pressure only, or by 

 pressure and heat combined ; still less can we tell whence 



