349. Why does dew form most abundantly on cloudless nights?
Because the heat which is radiated by the earth does not return to it. The temperature of the earth, and the air immediately upon its surface, is therefore lowered, and dew is formed.
It has been observed that sheep that have lain on the grass during the formation of dew have their backs completely saturated with it, but that underneath the line where their bodies turn to the earth, their coats will be dry. In the same manner glass globes suspended in the air, on dew forming nights, will be found loaded with globules of dew upon the top, but there will be no appearance of moisture underneath.
"Dost thou know the balancings of the clouds, the wondrous works of him which is perfect in knowledge."—Job xxxvii.
350. Why are star-lit nights usually colder than cloudy nights?
Because heat is radiated from the earth, and passes away into the utmost regions of the atmosphere.
351. Why is there little dew under branches of thick foliage?