.

WHAT COLUMBUS DISCOVERED.
A little over three hundred years ago there was a Pope of Rome whose name was Gregory XIII.

He was greatly interested in learning and science, and when the scholars and wise men of his day showed him that a mistake in reckoning time had long before been made he set about to make it right.

At that time the Pope of Rome had great influence with the kings and queens of Europe, and whatever he wished them to do they generally did.
So they all agreed to his plan of renumbering the days of the year, and a new reckoning of time was made upon the rule that most of you know by heart in the old rhyme: Thirty days hath September, April, June and November; All the rest have thirty-one, Excepting February which alone Hath twenty-eight--and this, in fine, One year in four hath twenty-nine.
And the order of the days of the months and the year is what is called, after Pope Gregory, the Gregorian Calendar.
This change in reckoning time made, of course, all past dates wrong.
The old dates, which were called Old Style, had to be made to correspond with the new dates which were called New Style.
Now, according to the Old Style, Columbus discovered the islands he thought to be the Indies (and which have ever since been called the West Indies) on the twelfth of October, 1492.

But, according to the New Style, adopted nearly one hundred years after his discovery, the right date would be the twenty-first of October.