A. As the bubble is suspended, the water keeps running down from the top to the bottom of the bubble, till the crown becomes so thin as to burst.
Q. Why are the late evening clouds red?
A. Because red rays (being the least refrangible) are the last to disappear.
Here it will be seen that the red ray PA, being reflected on the horizon at A, will be visible to us; but the yellow and blue rays will be hidden by the curve of the earth.
Q. Why are the early morning clouds red?
A. Because red rays (being the least refrangible) are the first to appear.
See last figure.—It is evident that PA (the red rays) will be reflected on the horizon before either the yellow or blue ones.
Q. What becomes of the blue and yellow rays?