417. _Does rain ever occur without clouds?_
It sometimes, but rarely happens, that a sudden transition from warmth to cold will _precipitate the moisture of the air_, without the formation of _visible clouds_.
[Verse: "Canst thou lift up thy voice to the clouds, that abundance of waters may cover thee?"--JOB XXXVIII.]
418. _Why are drops of rain sometimes large and at other times small?_
Because the drops, in falling, _meet and unite_, and also gather _moisture_ in their descent. The greater the height from which a rain drop has descended, _the larger it is_, provided that its whole course lay through a _rainy atmosphere_.
The size of the drops is also influenced by the _amount of moisture in the atmosphere_, the _degree of cold_, and the _rapidity_ of the _change of temperature_, by which the drops are produced.
419. _In what seasons of the year are rains most prevalent?_
Throughout _Central Europe_ rains are most prevalent in _summer_, but in _Southern Europe_ the preponderance is on the side of _winter rains_.
420. _In what months of the year does it rain most frequently in this country?_
It rains more frequently _from September to March_, than from _March to September_; but the _heaviest rains_ occur from _March to September_.
421. _Why are there more rainy days from September to March?_
Because the temperature of the air is more frequently lowered to that degree which _precipitates its vapours_.
_Months in the order of their comparative wetness_:--1. October. 2. February. 3. July. 4. September. 5. January. 6. December.
_Months in the order of their comparative dryness_:--1. March. 2. January. 3. May. 4. August. 5. April. 6. November.
422. _In what part of the world does the greatest quantity of rain fall?_
The greatest _quantity_ of rain falls near the _equator_, and the amount _decreases towards the poles_.
[Verse: "Who can number the clouds in wisdom? or who can stay the bottles of heaven."--JOB XXXVIII.]
423. _In what part of the world do the heaviest rains occur?_
The _heaviest_ rains occur in the _tropics_, during the hot season. The drops of rain in the tropical regions are so large, and the force with which they descend so great, that their splash upon the skin causes a _smarting sensation._