“Not I, master,” said Roger.
“Well, I’ll tell you. Suppose you wanted a measure of time answering to a year, you might reckon from the time the apples blow to when they blow again, but if a frost or a blight seize them, you’d be out with your count, wouldn’t you?”
“Truly,” said Mistress Margery, who delighted to see how well Roger understood his learned master.
“Well, then,” resumed the teacher, “you would soon find that if you wanted a regular, unchangeable guide, one unaffected by seasons, by droughts, heats, or hostile winds, you would look to the skies. You would, perhaps, if you were wise enough, and had observed—you would single out some special star; you would take close notice of its position, note its changes, then you would say, ‘When that comes back to the very spot where it was when I began to watch it, that time I shall count as my year.’ Do you follow me?”
“That I do,” said Roger.
“That, then, is one way in which a year was once calculated, and the star chosen gave three hundred and sixty-five days for a year.”
“Now that is a calendar, true and unchangeable, and correct beyond what a Pope can make,” said Caleb.
“That, Roger,” said Simon, taking no notice of Caleb, “is called a Sidereal year. Now, come you here, Phœbe, and tell me what is a Lunar year?”
“A year of moons,” said Phœbe, her bright eyes dancing.
“You have the making of a scholar in you,” said Simon; “’tis a pity you are a girl. A Lunar year is a year of twelve moons. This Lunar year has but three hundred and fifty-four days, still it served the purposes of the Chaldeans, the Persians, and Jews.