not, senor."

"Good! At last there is one fact about glass-making that I can impart
to you. This sort of glass is known as sand-blast glass, and the art of
making it, they say, chanced to be discovered near the seashore. It was
found that when the strong winds rose and blew the sand against glass
window-panes of the houses the small particles, being sharp, cut into
the glass surface, and before long wore it to a cloudy white through
which it was impossible to see out. Often the glass fronts of
lighthouses were injured in this way and the lights dimmed. Finally
some man came along who said: 'See here! Why not turn this grinding
effect of the sand to some purpose? Why not apply it to transparent
glass and make it frosted so one can get light but not see through it?
Often such glass would be a convenience.' Therefore this inventor set
his brain to the task. Strong currents or streams of sand were directed
against a clear glass surface with such force that they cut and ground
it until it was no longer transparent. They called the product thus
made sand-blast glass. Later they improved upon it by laying a stencil
over it so that a desired design was covered and remained protected
from the sand blast. The result was a pattern such as you see--clear
figures set in a background of clouded glass."

"How interesting!"

"Yes, isn't it? As is true of so many other of our most clever
inventions nature first showed man the path. Ground glass in its
modified forms is used for many purposes now; and yet I venture to say
few persons know how it came to be discovered."

Just at this point the car stopped with a sudden jerk, and beckoning
Jean and Giusippe to follow, Mr. Cabot got out and entered a large
brick building that stood close at hand. Evidently he was expected, for
a man came forward to greet him.

"Mr. Cabot?" he asked.

"Yes. I received your note this morning, so I brought my young charges
out at once. It is very good of you to allow us to go through the
factory."

"We are always glad to see visitors. I will put you in the hands of one
of our foremen who will take you about and tell you everything you may
want to know."

He touched a bell.

"Show Mr. Cabot and his friends down-stairs," said he to the boy who
answered his call, "and introduce them to Mr. Wyman. Tell him he is to
conduct them over the works."

Mr. Wyman welcomed them cordially.

"We see many visitors here, sir," said he, "and are always glad to h