But it is not necessary to go into the details of this phenomenon.

The reader, if he chooses, can deduce them for himself.
But we may inquire a little into the effects of the long days and nights of the moon.

In consequence of the extreme rarity of the lunar atmosphere, it is believed that the heat of the sun falling upon it during a day two weeks in length, is radiated away so rapidly that the surface of the lunar rocks never rises above the freezing temperature of water.

On the night side, with no warm atmospheric blanket such as the earth enjoys, the temperature may fall far toward absolute zero, the most merciful figure that has been suggested for it being 200 deg.

below the zero of our ordinary thermometers! But there is much uncertainty about the actual temperature on the moon, and different experiments, in the attempt to make a direct measurement of it, have yielded discordant results.