To cut a Glass, a Looking-glass, or even a Piece of Crystal, let it be ever so thick, without the Help of a Diamond, in the same Shape as the Mark of the Drawing made on it with Ink.
This remarkable operation unites utility with amusement. For being in the country, or in a place where there is no glazier nor glassman to be had, the following means will answer the purpose without their help.
Take a bit of a walnut-tree, about the thickness of a candle, and cut one of its ends to a point; put that end in the fire, and let it burn till it is quite red. While the stick is burning, draw on the glass or crystal, with ink, the design or outline of the form inwhich you mean to cut it out. Then take a file or a bit of glass and scratch a little the place where you mean to begin your section; then take the wood red hot from the fire, and lay the point of it about the twentieth part of an inch, or thickness of a guinea, from the marked place; taking care to blow always on that point in order to keep it red; follow the drawing traced on the glass, leaving, as before, about the twentieth part of an inch interval every time that you present your piece of wood, which you must take care to blow often.
After having followed exactly the outlines of your drawing, to separate the two pieces thus cut, you need only pull them up and down, and they will divide.