“And left the fraction to shift for itself!”

“Yes, but the consequence was, that the civil year was always nearly a quarter of a day behind; so that at the end of a hundred and twenty-one years the civil year had become an entire month behind.  The first month of winter found itself in autumn, the first month of spring in the middle of winter, and so on.

“Rather a lubberly sort of log, that,” remarked Willis.

“This confusion became, with time, more and more embarrassing.  Another evil was, likewise, eventually to be apprehended, for it was seen that, on the expiring of fourteen hundred and sixty revolutions of the earth round the sun, fourteen hundred and sixty-one civil years would be counted.”

“But where would have been the evil?”

“All relations between the dates and the seasons would have been obliterated, astronomical calculations would have become inaccurate, and the calendar virtually useless.”

“Well, Willis, you that are so fertile in ideas, what would you have done in such a case?” inquired Jack.

“I!  Why I scarcely know—­perhaps run out a fresh cable and commenced a new log.”

“Your remedy,” continued Wolston, “might, perhaps, have obviated the difficulty; but Julius Caesar thought of another that answered the purpose equally well.  It was simply to add to every fourth civil year an additional day, making it to consist of three hundred and sixty-six instead of three hundred and sixty-five, This supplementary day was given to the month of February.”

“Why February?”

“Because February, at that time, was reckoned the last month of the year.  It was only in the reign of Charles IX. of France, or in the second half of the sixteenth century, that the civil year was made to begin on the 1st of January.  As the end of February was five days before the 1st or kalends of March, the extra day was known by the phrase bis sexto (ante) calendus martii.  Hence the fourth year is termed in the calendar bissextile, but is more usually called by us in England leap year.”

“The remedy is certainly simple; but are your figures perfectly square?  If you add a day every four years, do you not overleap the earth’s fraction?”

“Yes, from ten to eleven minutes.”

“And what becomes of these minutes?  Are they allowed to run up another score?”

“No, not exactly.  In 1582, the civil year had got ten clear days the start of the solar year, and Pope Gregory XIII. resolved to cancel them, which he effected by calling the day after the 4th of October the 15th.”

“That manner of altering the rig and squaring the yards,” said Willi laughing, “would make the people that lived then ten days older.  If it had been ten years, the matter would have been serious.  Had the Pope said to me privately, ’Willis, you are now only forty-seven, but to-morrow, my boy, you will fill your sails and steer right into fifty-seven,’ I should have turned ’bout ship and cleared off.  Few men care about being put upon a short allowance of life, any more than we sailors on short rations of rum.”