To Cut a Phial in Half.
Wind round it two bands of paper, corresponding in position to the two temperate zones of the earth, leaving a space between, corresponding to the equatorial zone. Secure the two bands of paper with thread or fine twine. Then wind a long piece of string once around the equatorial space. Let an assistant hold one end of the string, and while holding the other end yourself, move the phial rapidly to and fro, so that the string shall work upon the glass between the two pieces of paper. When the glass becomes hot in the equatorial space, pour some cold water upon it, and the glass will break as evenly as if cut with a knife.
CUTTING THE PHIAL.
The principle involved in this curious experiment may be applied to the removal of a glass stopper, when too tight in the neck of the bottle for the fingers to stir it. All that is necessary is to wind a piece of thick string round the neck of the bottle, get an assistant to hold one end, and then work the bottle to and fro. The glass of the neck will become so warm as to expand, and the stopper will become loosened. It is often necessary to continue this friction for some minutes before the desired result is attained.