3. So did he when he got home! As for the butterfly, I have every reason to believe it died a natural death some time later.
CHAPTER LIX.—FIRE-BALLOONS AND GAS-BALLOONS: HOW TO MAKE AND USE THEM.
By the late Dr. Scoffern.
I.—THE PRINCIPLE OF BALLOONING.
Every boy at some time or other, I suppose, has felt himself irresistibly drawn towards the subject of toy-balloons; but first unaided experiments in that direction seldom prove altogether satisfactory, or maybe even pleasant. It is my intention, therefore, to go into the matter thoroughly and practically, explaining all about fire-balloons, and telling you at once how to make and use them.
If a thing—anything—be placed in the midst of any other thing lighter than itself, and if thing number two be not a solid, but either a liquid or a gas, both which permit of motion in any direction, then thing number one will ascend.
If you want to have this demonstrated, just plunge a cork down into water and see what happens. If instead of a cork you were to take a lump of iron—say a cannon ball—then the very idea of such a heavy material floating would seem to you ridiculous. It will float, nevertheless, not in water, truly, but in any fluid of greater weight than itself. Quicksilver, otherwise called mercury, is such a fluid, and the very experiment I have supposed you to perform for curiosity is actually turned to practical account by artillerists when they wish to ascertain whether a cannon ball is equally heavy on every part of corresponding size around the centre. If not equally heavy, then spots marked upon it will not float upwards equally well. If any particular spot insists on turning downwards, then the result proves that one side of the round cannon ball (please excuse the word side, a sphere really has no sides) is heavier than the rest.
But to return to our balloons. Well, please remember the globe on which we live is surrounded by an atmosphere—air we call it—and also please understand this atmosphere has weight; consequently it follows that anything lighter than the atmosphere will ascend in the atmosphere. In this we have the whole theory of balloons and ballooning.