"In connection with this matter of temperature it is necessary to remember that the days and nights upon the moon are both very long, for the full lunar 'day' is equal to a month, so the actual lunar day is equal to fourteen of our days, and the lunar night is of the same duration. Our 'day' of twenty-four hours is divided into day and night in unequal proportions, according to the changes in the seasons; but, as I before remarked, the seasonal changes on the moon are very slight, so the variations in the lengths of the days and nights are very small. "But, whatever may be the difference of opinion as to the heat of the lunar day, there seems to be a pretty general agreement that, owing to the absence of an atmosphere, the nights must be so intensely cold as to be almost beyond our conception--probably approaching nearly to the absolute zero of outer space. Even with an atmosphere the long nights in our polar regions are so cold that only very strong people can endure them, notwithstanding every device for obtaining warmth. "You will gather from this that although the moon appears so beautiful from a distance, it must be anything but a desirable place of residence even from a climatic point of view, for we should practically be fried at midday, while at midnight--or even in the daytime when out of the direct rays of the sun--we should soon be frozen stiff." As I said this John chimed in with: "Professor, all things considered, I think I could smoke my pipe more comfortably upon the earth than upon the moon. I really don't like such extremes of temperature." "I am of the same mind," I replied, "and it is because I prefer a more equable temperature that I have carefully kept our martalium blinds drawn over those windows of our vessel upon which the sun is shining." CHAPTER V WE VIEW THE LUNAR SCENERY IN THE NORTHERN HEMISPHERE "Now, Professor," exclaimed M'Allister, jumping up with a shrug of the shoulders, "you've given our friend John a considerable amount of information on a wee bit dry subject, so, mayhap, you will now give us something more interesting, and go on with the description of the natural features of the moon down yonder." "Yes do, please, Professor," said John; "M'Allister's own temperature is evidently rising rapidly. Strange, isn't it, that a douche of cold facts should make our friend so warm!" "Well, not altogether," I replied laughingly; "there should always be a healthy reaction after a cold douche. Much depends on the intensity of the cold applied, and you know that if you touch extremely cold metal it burns you like hot iron!" "Professor," chimed in M'Allister, "maybe I _was_ a bit warm, but really your facts were not so cold as to make me hot." "I'm glad to hear you say so," I answered.