floating about in mid-air, until I reach New York! Well, I'm sure I can't complain, for this cushion of air is about as soft as any feather-bed I ever lay on; but I feel sort of queer at thus continually falling without ever getting anywhere."
He was interrupted in his scientific meditations by a fly, which had, in some manner, found its way into the car, and now came and alighted upon his nose. William slapped it violently away with his hand; and as he did so he noticed that the motion had thrown his body somewhat out of the perpendicular. But if our hero was surprised at this, his astonishment may be imagined when he perceived that his body was slowly revolving, so that he soon found himself lying horizontally in the air; and a little later he was standing upright—if any one can be said to stand when resting on nothing but air.
"Good gracious!" he exclaimed, "I'm turning around in a circle!"
He was right; and as he had studied mechanics at school, it did not take him long to see the cause of this curious fact. He knew that no action could take place without a corresponding reaction, and that the force used in moving his hand to brush away the fly, working against the resistance
