We use iron and sand first, because they cut faster than anything else.
But you see how rough they leave the surface. Now see the second process.
This wheel is of fine stone, and only water drips on it from the hopper.
This man takes the glass as the other leaves it, and grinds off the
rough surface. But it still has a dull look, as you see; and that brings
us to the third process. Here the dull surface is polished on a wooden
wheel, with pumice-stone and water. For the finest work, a cork wheel is
used, with what we call putty,-- a paste composed of lead and tin."
"Hallo!" said Lawrence, "this is what I wanted
to see!" as he found a man finishing round facets that had been cut
through the thin colored shell of a ruby lamp-shade into the transparent
glass beneath.
The foreman was now called away, and Lawrence
was left to wander about as he pleased. He watched for a long time a
number of men cutting caster-bottles, wondering at the rapidity with which
they turned them from angle to angle on the stones. He saw one man fitting
glass stoppers to decanters,-- a simple process by which they were made
air-tight. The stopper, set fast in a lathe, was set whirling, and ground
down roughly at first with a piece of sheet-iron in sand and water. It
was then inserted in the neck of the decanter, and ground on that until
it fitted. Three of four workmen were cutting stars in the bottoms of
preserve-dishes, while others were simply taking off the rough spot left by
the ponty on the bottoms of articles that had been blown.
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