"By no means," said the Professor. "For then the calendar could not have been regulated so that the months and festivals would keep pace with the seasons. If 365 days had been constantly taken for a year, Christmas, instead of staying in the winter, would long since have moved back through autumn into summer, and so on. In about 1400 years it would travel through the entire circle of the seasons, as it would come some six hours earlier every year than it did the last. In like manner the Fourth of July would gradually fall back into spring, then into winter; and the fire-works would have to be set off in the midst of a snow-storm. The old Romans saw the difficulty; and, to prevent it, Julius Cæsar added an extra day to every fourth year, which you see is the same thing as adding one-fourth of a day to each year, only it is much more convenient. This was done because the earth requires nearly 365¼ days to move round the sun. The year that receives the extra day is called, as you know, leap-year. But even this did not keep the calendar exactly right. In the course of time other changes had to be made, the greatest of which was in 1582, when Pope Gregory XIII. decreed that ten entire days should be dropped out of the month of October. This was called the change from Old to New Style."
"It was rather stupid," said Gus, "to shorten the pleasantest month in the whole year. I would have clipped December or March."
"Please don't forget to tell us," said May, "how the months got their names."
"The first six of them were called after the heathen deities, Janus, Februus, Mars, Aphrodite, Maia, and Juno; July was named after Julius Cæsar, the inventor of leap-year; August after Augustus the Emperor. The names of the last four months simply mean seventh, eighth, ninth, and tenth."
"But," said Joe, "December is not the tenth month, nor is September the seventh."
"That is true," said the Professor; "but those names are supposed to have been given by Romulus, who arranged a year of only ten months, and made it begin with March. His year only had 304 days in it, and was soon found to be much too short. So the months of January and February were added, and instead of being placed at the end, they came in some way to stand at the beginning."
"Now please tell us about the names of the days of the week, and we will not ask any more questions."
"They were called after the sun, moon, and five planets known to the ancients, Mars, Mercury, Jupiter, Venus, and Saturn. You easily recognize sun, moon, and Saturn, Tuesday, Thursday, and Friday are from names given by some of the Northern tribes of Europe to Mars, Jupiter, and Venus. Mercury's day seems scarcely at all connected with his name, but comes from Wodin, who was imagined to be chief among the gods of those barbarous tribes."