Soap Bubbles
and the Forces which Mould Them

1^8 SOAP-BUBBLES, AND it has ceased to produce any visible effect on pieces of paper, or even on a delicate gold-leaf electroscope. Bouncing Water-jets. This beautiful experiment of Lord Ray- leigh’s requires a little management to make it work in a satisfactory manner. Take a piece of quill-glass tube and draw it out to a very slight extent (see a former note), so as to make a neck about one-eighth of an inch in diameter at the narrowest part. Break the tube just at this place, after first nicking it there with a file. Connect each of these tubes by means of an india-rubber pipe, or other- wise, with a supply of water in a bottle, and pinch the tubes with a screw-clip until two equal jets of water are formed. So hold the nozzles that these meet in their smooth por- tions at every small angle. They will then for a short time bounce away from one another without mixing. If the air is very- dusty, if the water is not clean, or if air- bubbles are carried along in the pipes, the two jets will at once join together. In the