other days in Lent as the ordinary should think proper; but at present it is performed on Ash Wednesday only. In this season they who lived in populous cities, or in the vicinity of the greater churches, held religious assemblies, and had sermons preached every day. The most antient manner of observing Lent was to refrain from all food till the evening for the change of diet, as of flesh for fish, was not, by the antients, accounted a fast. Their only refreshment was a moderate supper, and they partook indifferently of animal or other food, In subsequent ages, the use of flesh and wine was generally prohibited. Some abstained from all creatures which once had life; some from all fish; others ate fowls as well as fish; others abstained from eggs, milk, and fruit, and ate only pulse, roots, or bread; others abstained even from these, and again others indulged themselves with the addition of a little salt and water to their bread. Frequenting places of public amusement, the use of the bath, and various pleasures, at other times accounted innocent, were forbidden during Lent. The most rational and christian-like way of spending Lent, is not to show A downcast look, and sowre. Thy sheaf of wheat Unto the hungry soule. To circumcise thy life. To show a heart grief-rent; To starve thy sin, Not bin; And that's to keep thy Lent. HERRICK. It is still a custom with some old people to wear black during Lent; and the clergy of the established church usually go without powder during this season. History of Astronomy. [Continued from p. 16.] From the Foundation of the Alexandrine School to the Time of the Arabs. HITHERTO, says La Place, the practical astronomy of different people has only offered us some rude observations relative to seasons and eclipses, objects connected either with their necessities or their terrors. Their theoretical astronomy consisted in the knowledge of some periods founded on very long intervals of time, and of some fortunate conjectures relative to the constitution of the universe, but mingled with a considerable share of error. In the school of Alexandria we have, for the first time, a connected series of observations made by instruments, and calculated upon scientific principles. From this period astronomy took a new form, which the following ages have adopted and brought to perfection. The positions of the fixed stars were determined; the paths of the planets carefully traced; and the inequalities of the motions of the Sun and Moon were better known. It was the school of Alexandria that gave birth to the first system of astronomy that had ever comprehended an entire plan of the celestial motions. This system was certainly very inferior to that of Pythagoras, but, being founded on a comparison of observations, it afforded the means of its own destruction, and the true system of nature has been reared on its ruins. After the death of Alexander, his empire was divided among his principal generals, and Ptolemy Soter received Egypt for his share. His munificence attracted to Alexandria, the capital of his kingdom, a great number of the most learned men of Greece. Ptolemy Philadelphus, who inherited his father's love of the sciences, established them under his own particular protection. He built an observatory and founded a most magnificent library. Here the learned were supplied with whatever books and instruments were necessary to their pursuits, and their emulation was excited by the example, as well as patronage, of a prince who often came among them to participate in their labour, and to improve by their conversation. Arystillus and Timocares, the first observers of this infant school, flourished about the year 300 before the Christian æra. Their observations of the principal stars of the zodiac enabled Hipparchus to discover the precession of the equinoxes [see pp. 16, 17]; and Ptolemy, from their observations of the planets, founded his theory of those bodies. The next astronomer was Aristarchus of Samos, who observed, very accurately, the summer solstice in the year 281 before Christ. He determined the magnitude of the apparent diameter of the Sun, and he attempted to determine the distance of the Sun from the Earth. He revived the opinion of Pythagoras relative to the motion of the Earth; but, as his writings have not come down to us, we are ignorant to what extent he carried his theory in his explanation of the celestial phenomena. Having considered that the motion of the Earth in its orbit produced no change in the apparent position of the stars, he placed them at distances incomparably greater than that of the Sun: hence it has been inferred, that, of all the antient astronomers, Aristarchus had formed the most just notions of the magnitude of the universe. His successor, Eratosthenes, is chiefly known from his measuring the Earth, and from his observations on the obliquity of the ecliptic. Having remarked, at the summer solstice, a very deep well, whose whole depth was illuminated by the Sun, at Syene, in Upper Egypt, he compared this with the altitude of the Sun at the same solstice at Alexandria. He found the celestial arc contained between the zeniths of the two places equal to a fiftieth part of the whole circumference; and as their distance was estimated, by measurement, to be 500 stadia, he fixed the length of the whole circumference at 250,000 stadia. The observation of Eratosthenes on the obliquity of the ecliptic is very valuable, as it confirms the diminution of it, determined a priori, by the theory of gravitation. But of all the astronomers of antiquity, the science is most indebted to Hipparchus of Bithynia, for the great number and extent of his observations, for the most important results which he obtained, for comparing them with those that had formerly been made by others, and for the excellent method which he pursued in his researches. Nothing affords a stronger proof of the uncertainty of the Egyptian and Chaldean observations on the Sun and stars, than the necessity which compelled him to recur to the observations of the Alexandrian school to establish his theories of the Sun, and of the precession of the equinoxes. He determined the length of the tropical year, by comparing one of his own observations of the summer solstice with one made by Aristarchus forty-five years before, and found it to be 365.24667 days, being an excess of the true value of only about 4 minutes. He also discovered that there elapsed 187 days from the vernal to the autumnal equinox, and 178 days only from the last to the former. He next considered the motions of the Moon, and measured the length of its revolution, by comparing eclipses, and he determined both the excentricity and inclination of its orbit; he ascertained the motion of its nodes, and of its apogee; and, from the determination of its parallax, endeavoured to infer that of the Sun, by the breadth of the cone of the terrestrial shadow, in an eclipse at the moment it was traversed by the Moon, which led him nearly to the same result as that which had been ob E tained by Aristarchus. A new star which appeared in his time, induced him to undertake a catalogue of the fixed stars, in order, as he said, that posterity might be able to recognize any changes that should take place in the appearance of the heavens. His great and eminent labours were rewarded by the discovery of the precession of the equinoxes; for, by comparing his observations with those of Aristillus and Timochares, he discovered that the stars had changed their situation with respect to the equator, but had preserved the same latitude with respect to the ecliptic; so that, to explain these different changes, it is sufficient to give a direct motion to the celestial sphere round the poles of the ecliptic, which produces a retrograde motion of the equinoxes with respect to the stars. Geography is indebted to Hipparchus for the method of determining places on the earth by their latitude and longitude. Spherical trigonometry also owes its origin to Hipparchus, who applied it to the numberless calculations which these 'investigations required. His principal works were destroyed in the conflagration of the Alexandrian library, and our knowledge of them is derived from the Almagest of Ptolemy. The interval of nearly three centuries, that which separated these two eminent astronomers, produced some observers, among whom were Agrippa, Menelaus, and Theon. In this interval are to be noticed the reformation of the calendar by Julius Cæsar, and the precise knowledge of the ebbing and flowing of the sea. It was Possidonius who observed the law of this phenomenon, which appertains to astronomy by its evident relation to the motion of the Sun and Moon, and of which Pliny has given a description remarkable for its exactness. Ptolemy flourished at Alexandria about the year 130 of the Christian æra. Hipparchus had conceived the project for reforming astronomy, and esta |