Q. Why does dew rarely fall upon hard rocks and barren lands?
A. Rocks and barren lands are so compact and hard, that they can neither absorb nor radiate much heat; and (as their temperature varies but very little) very little dew distils upon them.
Q. Why does dew fall more abundantly on cultivated soils, than on barren lands?
A. Because cultivated soils (being loose and porous) absorb heat freely during the day, and radiate it by night; and (being much cooled by the rapid radiation of heat) as the vapour of the air passes over them, it is plentifully condensed into dew.
Q. Shew the wisdom of God in this arrangement.
A. Every plant and inch of land which needs the moisture of dew, is adapted to collect it; but not a single drop even of dew is wasted, where its refreshing moisture is not required.
Q. Shew the wisdom of God in making polished metal and woollen cloth bad radiators of heat.
A. If polished metal collected dew as easily as grass, it could never be kept dry, and free from rust. Again, if woollen garments collected dew as readily as the leaves of trees, we should be often soaking wet, and subject to constant colds.
Q. Shew how this affords a beautiful illustration of Gideon’s miracle, recorded in the book of Judges, VI. 37, 38.