CHAPTER I.

EARLIEST STAGES OF ASTRONOMY.

Sect. 1.-Formation of the Notion of a Year.

THE notion of a Day is early and obviously impressed upon man in almost any condition in which we can imagine him. The recurrence of light and darkness, of comparative warmth and cold, of noise and silence, of the activity and repose of animals;— the rising, mounting, descending, and setting of the sun; the varying colours of the clouds, generally, notwithstanding their variety, marked by a daily progression of appearances;-the calls of the desire of food and of sleep in himself, either exactly adjusted to the period of this change, or at least readily capable of being accommodated to it; these circumstances, recurring at intervals, equal, so far as man's obvious judgment of the passage of time can decide; and these intervals so short that the repetition is noticed with no effort of attention or memory; this assemblage of suggestions makes the notion of a day necessarily occur to man, if we

suppose him to have the conception of time, and of recurrence. He naturally marks by a term such a portion of time, and such a cycle of recurrence; he calls each portion of time, in which this series of appearances and occurrences come round, a day: and such a group of particulars are considered as appearing or happening in the same day.

A year is a notion formed in the same manner; implying in the same way the notion of recurring facts; and also the faculty of arranging facts in time, and of appreciating their recurrence. But the notion of a year, though undoubtedly very obvious, is, on many accounts, less so than that of a day. The repetition of similar circumstances, at equal intervals, is less manifest in this case, and the intervals being much longer, some exertion of memory becomes requisite in order that the recurrence may be perceived. A child might easily be persuaded that successive years were of unequal length; or, if the summer were cold, and the spring and autumn warm, might be made to believe, if all who spoke in its hearing agreed to support the delusion, that one year was two. It would be impossible to practise such a deception with regard to the day, without the use of some artifice beyond mere words.

Still, the recurrence of the appearances which suggest the notion of a year is so obvious, that we can hardly conceive man without it. But though, in all climes and times, there would be a recurrence, and at the same interval in all, the recurring appear

Yet

ances would be extremely different in different countries; and the contrasts and resemblances of the seasons would be widely varied. In some places the winter utterly alters the face of the country, converting grassy hills, deep leafy woods of various hues of green, and running waters, into snowy and icy wastes, and bare snow-laden branches; while in others, the field retains its herbage, and the tree its leaves, all the year; and the rains and the sunshine alone, or various agricultural employments quite different from ours, mark the passing seasons. in all parts of the world the yearly cycle of changes has been singled out from all others, and designated by a peculiar name. The inhabitant of the equatorial regions has the sun vertically over him at the end of every period of six months, and similar trains of celestial phenomena fill up each of these intervals, yet we do not find years of six months among such nations. The Arabs alone', who practise neither agriculture nor navigation, have a year depending upon the moon only; and borrow the word from other languages, when they speak of the solar year.

In general nations have marked this portion of time by some word which has a reference to the returning circle of seasons and employments. Thus the Latin annus signified a ring, as we see in the derivative annulus: the Greek term éviavròs implies something which returns into itself: and the word as it exists

1

Ideler, Berl. Trans. 1813, p. 51.

VOL. I.

in Teutonic languages, of which our word year is an example, is said to have its origin in the word yra, which means a ring in Swedish, and is perhaps connected with the Latin gyrus.

Sect. 2.-Fixation of the Civil Year.

THE year, considered as a recurring cycle of seasons and of general appearances, must attract the notice of man as soon as his attention and memory suffice to bind together the parts of a succession of the length of several years. But to make the same term imply a certain fixed number of days, we must know how many days the cycle of the seasons occupies; a knowledge which requires faculties and artifices beyond what we have already mentioned. For in

stance, men cannot reckon as far as any number at all approaching the number of days in the year, without possessing a system of numeral terms, and methods of practical numeration on which such a system of terms is always founded2. The South American Indians, the Koussa Caffres and Hottentots, and the natives of New Holland, all of whom are said to be unable to reckon further than the fingers of their hands and feet, cannot include, in their notion of a year, the fact of its consisting of 365 days, as we do. This fact is not likely to be

* Arithm. in Encyc. Metrop. (by Mr. Peacock,) Art. 8.

3 Ibid. Art. 32.

known to any nation except those which have advanced far beyond that which may be considered as the earliest scientific process which we can trace in the theoretical history of the human race, the formation of a method of designating the successive numbers to an indefinite extent, by means of names, framed according to the decimal, quinary, or vigenary scale.

But even if we suppose men to have the habit of recording the passage of each day, and of counting the score thus recorded, it would be by no means easy for them to determine the exact number of days in which the cycle of the seasons recurs; for the indefiniteness of the appearances which mark the same season of the year, and the changes to which they are subject as the seasons are early or late, would leave much uncertainty respecting the duration of the year. They would not obtain any accuracy on this head, till they had attended for a considerable time to the motions and places of the sun; circumstances which require more precision of notice than the general facts of the degrees of heat and light. The motions of the sun, the succession of the places of his rising and setting at different times of the year, the greatest heights which he reaches, the proportion of the length of day and night, would all exhibit several cycles. The returning back of the sun, when he had reached his greatest distance to the south or to the north, as shown either by his rising or by his height at noon,