This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Glass may be cut without a diamond. Dip a piece of common string in alcohol and squeeze it reasonably dry. Then tie the string tightly around the glass on the line of cutting. Touch a match to the string and let it burn off. The heat of the burning string will weaken the glass in this particular place. While it is hot plunge the glass under water, letting the arm go well under to the elbow, so there will be no vibration when the glass is struck. With the free hand strike the glass outside the line of cutting, giving a quick, sharp stroke with a stick of wood, a long-bladed knife, or the like, and the cut will be as clean and straight as if made by a regular glass cutter.
The same principle may be employed to cut bottles into vases, and to form all sorts of pretty things, such as jewelry boxes, picture panes, trays, small tablets, windows for a doll house, etc.
Scratch the glass around the shape you desire with the corner of a file or graver; then, having bent a piece of wire into the same shape, heat it red hot and lay it upon the scratch and sink the glass into cold water just deep enough for the water to come almost on a level with its upper surface. It will rarely fail to break perfectly true.
It is possible to cut a sheet of glass roughly to any desired shape with an ordinary pair of scissors, if the operation be performed under water. Of course, a smooth edge cannot be obtained by such means, but it will be found satisfactory.
Take any good piece of steel wire, file to the shape of a drill, and then hold it in a flame till it is at a dull red heat; then quench in metallic mercury. A piece of good steel, thus treated, will bore through glass almost as easily as through soft brass. In use, lubricate with oil of turpentine in which camphor has been dissolved. When the point of the drill has touched the other side put the glass in water, and proceed with the drilling very slowly. If not possible to do this, reverse the work—turn the glass over and drill, very carefully, from the opposite side. By proceeding with care you can easily drill three holes through glass 3/16 inch thick 1/4 of an inch apart, In making the drill be careful not to make the point and the cutting edges too acute. The drill cuts more slowly, but more safely, when the point and cutting edges are at a low angle.
To produce holes in panes of thin or weak glass, provide the places to be perforated with a ring of moist loam, whose center leaves free a portion of glass exactly the size of the desired hole. Pour molten lead into the ring, and the glass and lead will fall through at once. This process is based upon the rapid heating of the glass.