important features of the glass industry of this country today. The
manufacture of window glass fades into insignficance before the hugeness
of the bottle-making business; and even the advent of prohibition, while
it lessens materially the demand for glass containers of liquids, does
not do so in such degree as to warrant very active uneasiness on the
part of the proprietors of bottle factories.

The process of manufacture of the humble bottle is a surprizingly
involved one. It includes the transportation and preparation of raw
material, the reduction of the material to a proper state of
workability, and the shaping of the material according to design, before
the bottle is ready to go forth on its mission.

The basic material of which all glass is made is, of course, sand. Not
the brown sand of the river-bed, the well remembered "sandy bottom" of
the swimmin' hole of our childhood, but the finest of white sand from
the prehistoric ocean-beds of our country. This sand is brought to the
factory and there mixed by experts with coloring matter and a flux to
aid the melting. On the tint of the finished product depends the sort of
coloring agent used. For clear white glass, called flint glass, no color
is added. The mixing of a copper salt with the sand gives a greenish
tinge to the glass; amber glass is obtained by the addition of an iron
compound; and a little cobalt in the mixture gives the finished bottle
the clear blue tone that used to greet the waking eye as it searched the
room for something to allay that morning's morning feeling. The flux
used is old glass--bits of shattered bottles, scraps from the floor of
the factory. This broken glass is called "cullet," and is carefully
swept into piles and kept in bins for use in the furnaces.

The sand, coloring matter, and cullet, when mixed in the proper