The basis of all glass is soda, aluminum or oxide of lead in combination with silica of sand. Doesn’t this sound hiphalutin? Well, it isn’t. Then this is heated to something like 1200 degrees Fahrenheit and when in molten form is blown with air incorporators into the requisite shapes. You no doubt have seen glass blown at bazaars or fairs. But of course this blowing in the factory is done with huge blowers. The best glass is dependent on its base as it is combined with lead. This combination is the fine glass called flint glass. And it is from flint glass which has the luster that the cut and engraved glass is made. COLOR The color in glass is given to it by the use of metal oxides, blue is derived from copper oxide, yellow from iron oxide, the stunning reds from gold. Don’t these facts, make glass more interesting to you? Rock crystal is the fashion now and probably will persist. But don’t, for goodness’ sake, be untechnical enough to say anything but polished engraved glass, when you speak of it! The old time glass with intersecting canyons cut in it which left tell tale gouges in one’s fingers, is dead and if you use it you are dead too! Now be it remembered, it’s polished engraved alias rock crystal. HOW IT DIFFERS FROM CUT GLASS Cut glass is decorated with geometric lines by means of steel wheels and carborundum used for the cutting. Then these lines are smoothed with stone wheels and given a high polish. Some manufacturers press in the design by putting the glass into moulds in its moulten state, but this makes the cheaper glass commonly called Pressed to imitate the cut variety. Then the glass is cooled and the effects are often good enough to fool the ordinary person. Cut glass can always be distinguished from the pressed by feeling the inside of the cutting, where it is the deepest, and if there is a slight lump corresponding to the cutting it is surely cut and not pressed. Engraved glass is thinner than the cut glass very often and is decorated by copper wheels fed with emery and oil, which does not cut so deep. The skill of the designer and workman are the only limits to the beauty of this glass. This kind of decoration is left in the satin gray finish with the exception of the polishing out of the centers of the flowers, and other figures according to the taste of the engraver. This gives the contrasts in gray and clear glass which give the tonal value to the glass. And when the engraving is sunk deeply and then polished, it is called rock crystal because it has the peculiar colorless mat-finish brilliancy of the natural rock crystal. COLORED GLASS