A. 1st—Because the clouds are heavy with abundant vapour: and
2ndly—As the density of the air is diminished, it is less able to buoy the clouds up.
Q. How do you know that the density of the air is diminished in rainy weather?
A. Because the mercury of a barometer falls.
Q. Why is rain-water more fertilizing than pump-water?
A. Because it contains a compound of hydrogen and nitrogen (called ammonia), which is a very excellent food for young plants.
Q. Why is November made by God to be a rainy month?
A. Because rain hastens the putrefaction of the fallen leaves by causing fermentation.
Q. Why does rain purify the air?