legal beginning of the year was changed from the 25th of March to the 1st of January. So that the succeeding months of January, Febru ary, and March, up to the 24th day, which would, by the Old Style, have been reckoned part of the year 1752, were accounted as the first three months of the year 1733. Hence we sometimes see such a date as this, Feb. 10, 1774-5, that is, according to the Old Style it was 1774, but according to the New it is 1775, because now the year begins in January 'instead of March.

The Old Style still prevails in Russia: but in every other part of Europe it is now abolished.

CONVERSATION XIV.

TUTOR.

Of the Moon.

You are now, gentlemen, acquainted with the reasons for the division of time into days and

years.

Charles.

These divisions have

their foundation in nature, the former depending upon the rotation of the earth on its axis; the latter upon its

revolution in an elliptic orbit

about the sun as a centre of motion.

James. Is there any natural reason for the division of years into weeks, or of days into hours, minutes, and seconds?

Tutor. The first of these divisions was introduced by Divine authority; the second class was invented for the convenience of mankind. There is, however, another division of time marked out by nature.

Charles. What is that, sir?

Tutor. The length of the month: not indeed that month which consists of four weeks, nor that by which the year is divided into 12 parts. These are both arbitrary. But by a month was originally meant the time which the moon takes in performing her journey round the earth

Then mark d astronomers with keener eyes
The moon's refulgent journey through the skies.

DARWIN.

James. How many days does the

moon take for this purpose?

Tutor. If you refer to the time in which the moon revolves from one point of the heavens to the same point again, it consists of 27 days, 7 hours, and 43 minutes; this is called the periodical month: but if you refer to the time passed from new moon to new moon again, the month consists of 29 days, 12 hours, and 44 minutes; this is called the synodical month.

Charles. Pray explain the reason of this difference.

Tutor. It is occasioned by the earth's annual motion in its orbit. Let us refer to our watch as an example. The two hands are together at 12 o'clock; now, when the minute-hand has made a complete revolution, are they together again?

James. No; for the hour hand is advanced the twelfth part of its

VOL. II.

revolution, which, in order that the other may overtake, it must travel five minutes more than the hour.

Tutor. And something more, for the hour-hand does not wait, at the figure I, till the other comes up: and therefore they will not be together till between 5 and 6 minutes after

one.

Now apply this to the earth and moon; suppose s

to be the sun; T the earth, in a part of its orbit QL; and E to be the po