Now, how are you going to do it?
Why, if you know when you are well off, you will do it with this hat.

But how?
I will explain.

If you compress air until it attains a considerable pressure, and then suddenly release it, the rapid expansion causes the air to absorb heat and to produce quite a marked degree of cold.

You know this, of course ?" "I wish you'd compress _your_ air, and then expand it in the ears of somebody besides me." "Now, in my invention I have utilized this beautiful law of nature in a manner that is certain to confer an inestimable blessing upon the human race.

This hat is really made of light boiler iron covered with silk.