"I guess there is no danger of the world being without clocks," returned Christopher comfortably. "There seem to be plenty to go round."
"But there weren't always plenty," broke in McPhearson quickly. "You chance to live in a fortunate age, young man, and do not half appreciate your blessings. Had you lived a few hundred years ago you would have had no clocks."
"Mercy on us! Why, how on earth did people manage to get on without them?"
"Primitive persons studied the sun and calculated by that," McPhearson responded. "Then some ingenious creature thought out the sundial whereby the hour could be gauged by a shadow; also marks were made where the sun would strike at a given time—perhaps at noon. Such a notch was called the noon mark."
"Oh, gee! But suppose there was no sun?"
"Exactly! Now you have put your finger on the pulse of the dilemma! What was to be done when there was no sun? The sundial at best was none too correct. In different latitudes, too, different markings were needed. Moreover, a sundial, to be of practical value, had to be kept steady. What was to happen on shipboard? On cloudy days? At night?"
"The sundial was about as much good as a fan would be in Greenland," grinned Christopher.
"Yes, just about. It was these sunless hours that were the problem."
"Humph! I never thought of that in my life."
"Most of us don't."