Soap Bubbles
and the Forces which Mould Them

12 SOAP-BUBBLES, AND which we ask of Nature, who is always ready to give a correct answer, provided we ask properly, that is, provided we arrange a proper experiment. An experiment is not a conjuring trick, something simply to make you wonder, nor is it simply shown because it is beautiful, or because it serves to relieve the monotony of a lecture ; if any of the experiments I show are beautiful, or do serve to make these lec- tures a little less dull, so much the better; but their chief object is to enable you to see for yourselves what the true answers are to questions that I shall ask. Now I shall begin by performing an experi- ment which you have all probably tried dozens of times. I have in my hand a common camel’s-hair brush. If you want to make the hairs cling together and come to a point, you wet it, and then you say the hairs cling to- gether because the brush is wet. N ow let us try the experiment; but as you cannot see this brush across the room, I hold it in front of the lantern, and you can see it enlarged upon the screen (Fig. i, left hand). Now it is dry, and the hairs are separately visible. I am now dipping it in the water, as you can