The simplest way of ascertaining the period of a tropical year is by observing the position of the sun relatively to the equator, or its declination, and this can conveniently be done either when the sun is on the horizon or on the meridian, but most easily with accuracy in the former way, as the angle to be subdivided will generally be greater, and greater accuracy will be attained, because long shadows can more conveniently be used in this way than in the other. Or the right ascension of the sun might also be observed; that is, its place among the stars, or its position in the zodiac. This can be found most readily by observing the heliacal rising of stars, or the meridian passage of stars when the sun is near the horizon. At Zimbabwe all of these methods seem to have been used, and to do so does not necessarily imply more astronomical knowledge than is possessed by the peasantry in any of the more secluded districts of Europe, where watches are not much used, and where almanacks are not read, but where the people have the habit of telling the time of the day and of the year by the motions of the sun and of the stars; for to an agricultural people the change in position of the sun in summer and winter is as obvious as the seasons themselves, and the variation of the times of rising of the stars with the seasons can as little escape observation. Herodotus tells us that the Greeks used the gnomon to measure the length of shadows, and thus ascertain the position of the sun at midday, or its declination. The Chinese also used it at a very early period, and we have similar arrangements in some of our modern churches. Instances of the observation of the position of the sun on the horizon, except at Zimbabwe, are few and doubtful, although gnomons seem sometimes to have been used for this purpose; but ancient literature contains very many references to the observation of the heliacal risings of stars, and ancient architectural remains illustrate these literary allusions. Hesiod often speaks of the times of different agricultural operations having been fixed by the rising of stars, and Egyptian records tell us that the rising of Sirius was observed at the overflowing of the Nile; also it has recently been found that both Egyptian and Greek temples were generally built so that the rising of some star could be observed from their sanctuaries, and a coincidence has been traced between the date of the great festival proper to each temple and the time of the heliacal rising of the star towards which the axis of the temple was originally directed. The Malays, at the beginning of this present century, had a tradition that their seed-time had in old days been very well fixed by the rising of the Pleiades, but that since they had become Mohammedans the festivals of their religion and its calendar did not so well regulate their seed-time as was done in old times. It has been found that means were provided by the ancient Egyptians for