I was so interested in seeing a bit of silver-like metal and water take
fire as they touched that I forgot all about the occasion of the noise.
HINT HELP
Benjamin C. B. Tilghman, of Philadelphia, once went into the lighthouse
at Cape May, and, observing that the window glass was translucent
rather than transparent, asked the keeper why he put ground glass in
the windows. "We do not," said the keeper. "We put in the clear
glass, and the wind blows the sand against it and roughens the outer
surface like ground glass." The answer was to him like the falling
apple to Newton. He put on his thinking cap and went out. It was
better than the cap of Fortunatus to him. He thought, "If nature does
this, why cannot I make a fiercer blast, let sand trickle into it, and
so hurl a million little hammers at the glass, and grind it more
swiftly than we do on stones with a stream of wet sand added?"
He tried jets of steam and of air with sand, and found that he could
roughen a pane of glass almost instantly. By coating a part of the
glass with hot beeswax, applied with a brush, through a stencil, or
covering it with paper cut into any desired figures, he could engrave
the most delicate and intricate patterns as readily as if plain. Glass
is often made all white, except a very thin coating of brilliant
colored glass on one side.
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