“And who invented the calendar?” inquired Willis.

“I am not aware that the calendar was ever invented,” replied Wolston.  “Fruit commences by being a seed, the admiral springs from the cabin-boy, words and language succeed naturally the babble of the infant; so, I presume, the calendar has grown up spontaneously to its present degree of perfection.”

“Yes, Mr. Wolston, but some one must have laid the first plank.”

“The motions of the sun, moon, and stars would, in all probability, suggest to the early inhabitants of our globe a natural means of measuring time.  God, in creating the heavenly bodies, seems to have reflected that man would require some index to regulate his labors and the acts of his civil life.  The primary and most elementary subdivisions of time are day and night, and it demanded no great stretch of human ingenuity to divide the day into two sections, called forenoon and afternoon, or into twelve sections, called hours.  Such subdivisions of time would probably suggest themselves simultaneously to all the nations of the earth.  Necessity, who is the mother of all invention, doubtless called the germs of our calendar into existence.”

“Yes, so far as the days and hours are concerned.  There are other divisions—­weeks, for example.”

“The division of time into weeks is a matter that belongs entirely to revelation; the Jews keep the last day of every seven as a day of rest, in accordance with the law of Moses, and the Christians dedicate the first day of every seven to our Lord and Saviour Jesus Christ.”

“Then there are months.”

“The month is another natural division.  The return of the moon in conjunction with the sun, was observed to occur at regular intervals of twenty-nine days, twelve hours, and some minutes.  This interval is called the lunar month, which for a long time was regarded as the radical unit in the admeasurement of time.”

“But the year is now the unit, is it not?”

“Yes, in course of time the moon, in this respect, gave place to the sun.  It was observed that the earth, in performing her revolution round the sun, always arrived at the same point of her orbit at the end of three hundred and sixty-five days, five hours, fifty-eight minutes, and forty-five seconds.”

“Does the earth invariably pass the same point at that interval?”

“Yes, invariably; and the interval in question is termed the solar year.”

“After all,” remarked Jack, “the perseverance of the earth is very much to be admired.  It goes on eternally, always performing the same journey, never deviates from its path, and is never a minute too late.”

“If the earth had performed her annual voyage in a certain number of entire days, the solar year would have been an exact unit of time; but the odd fraction defied all our systems of calculation.  Originally, we reckoned the year to consist of three hundred and sixty-five days.”