As in the days of the week, so in the festivals of the year, we trace their first origin to astronomical observations. When nations passed from the condition of savages, hunters, or nomads, into the agricultural stage, and developed dense populations, cities, temples, priests, and an organized society, we find the oldest traces of it everywhere in the science of astronomy. They watched the phases of the moon, counted the planets, followed the sun in its annual course, marking it first by seasons, and, as science advanced, by its progress through groups of fixed stars fancifully defined as constellations. Everywhere the moon seems to have been taken as the first standard for measuring time beyond the primary unit of day and night. Its name very generally denotes the "Measurer" in primitive languages, and it appears as the male, and the sun as female, in the oldest mythologies--a distinction of sex which is still maintained in modern German. This is natural, for the monthly changes of the moon come much more frequently, and are more easily measured from day to day, than the annual courses of the sun. But, as observations accumulate and become more accurate, it is found that the sun, and not the moon, regulates the seasons, and that the year repeats on a larger scale the phenomenon presented by the day and night, of a birth, growth, maturity, decay, and death of the sun, followed by a resurrection or new birth, when the same cycle begins anew. Hence the oldest civilized nations have taken from the two phenomena of the day and year the same fundamental ideas and festivals. The ideas are those of a miraculous birth, death, and resurrection, and of an upper and lower world, the one of light and life, the other of darkness and death, through which the sun-god and human souls have to pass to emerge again into life. The festivals are those of the four great divisions of the year: the winter solstice, when the aged sun sinks into the tomb and rises again with a new birth; the spring equinox, when he passes definitively out of the domain of winter into that of summer; the summer solstice, when he is in full manhood, "rejoicing like a giant to run his course," and withering up vegetation as with the hot breath of a raging lion; and, finally, the autumnal equinox, when he sinks once more into the wintry half of the year and fades daily amidst storms and deluges to the tomb from which he started. Of these festivals Christmas and Easter have survived to the present day, and the last traces of the feast of the summer solstice are still lingering in the remote parts of Scotland and Ireland in the Bel fires, which, when I was young, were lighted on Midsummer night on the highest hills of Orkney and Shetland. As a boy, I have rushed, with my playmates, through the smoke of those bonfires without a suspicion that we were repeating the homage paid to Baal in the Valley of Hinnom.