Soda is a common article, and is very easily produced by artificial means.  Potash, which has the same properties as soda, exists in all ashes.

Now silica, and lime, and soda, or potash, when melted together, form glass.  So you see that the materials for making this substance which adds so much to our comfort and pleasure are freely given to all countries.  And after Venice had set the example, other nations turned their attention to the study of glass-making, and soon found out this fact, in spite of the secrecy of the Venetians.  After a time the Germans began to manufacture glass; and then the Bohemians.  The latter invented engraving on glass, which art had also been known to the ancients, and then been lost.  They also learned to color glass so brilliantly that Bohemian glass became more fashionable than Venetian, and has been highly thought of down to the present day.

On the next page we see an immense drinking-glass of German manufacture, but this one was made many years after glass-making was first started there.

This great goblet, which it takes several bottles of wine to fill, was passed around at the end of a feast, and every guest was expected to take a sip out of it.  This was a very social way of drinking, but I think on the whole it is just as well that it has gone out of fashion.

The old Egyptians made glass bottles, and so did the early Romans, and used them just as we do for a very great variety of things.  Their wine-bottles were of glass, sealed and labelled like ours.  We might suppose that, having once had them, people would never be without glass bottles.  But history tells a different story.  There evidently came a time when glass bottles vanished from the face of the earth; for we read of wooden bottles and those of goat-skin and leather, but there is no mention of glass.  And men were satisfied with these clumsy contrivances, because in process of time it had been forgotten that any other were ever made.

[Illustration]

Hundreds of years rolled away, and then, behold! glass bottles appeared again.  Now there is such a demand for them that one country alone—­France—­makes sixty thousand tons of bottles every year.  To make bottle-glass, oxide of iron and alumina is added to the silica, lime, and soda.  It seems scarcely possible that these few common substances melted over the fire and blown with the breath can be formed into a material as thin and gossamer, almost, as a spider’s web, and made to assume such a graceful shape as this jug.

[Illustration]

This is how glass bottles, vases, etc., are made.  When the substances mentioned above are melted together properly, a man dips a long, hollow iron tube into a pot filled with the boiling liquid glass, and takes up a little on the end of it.  This he passes quickly to another man, who dips it once more, and, having twirled the tube around so as to lengthen the glass ball at the end, gives it to a third man, who places