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ASTRONOMY
[GENERAL

Then followed a letter to a person of quality giving a full and particular account of the death of Partridge on the very day and nearly at the hour mentioned. In vain the wretched astrologer protested that he was alive, got a literary friend to write a pamphlet to prove it, and published his almanac for 1709. Swift, in his reply, abused him for his want of manners in giving a gentleman the lie, answered his arguments seriatim, and declared that the evidence of the publication of another almanac was wholly irrelevant, “for Gadbury, Poor Robin, Dove and Way do yearly publish their almanacs, though several of them have been dead since before the Revolution.” Nevertheless a field is found even to this day for almanacs of a similar type, and for popular belief in them.

To astrological politics we owe the theory of heaven-sent rulers, instruments in the hands of Providence, and saviours of society. Napoleon, as well as Wallenstein, believed in his star. Many passages in the older English poets are unintelligible without some knowledge of astrology. Chaucer wrote a treatise on the astrolabe; Milton constantly refers to planetary influences; in Shakespeare’s King Lear, Gloucester and Edmund represent respectively the old and the new faith. We still contemplate and consider; we still speak of men as jovial, saturnine or mercurial; we still talk of the ascendancy of genius, or a disastrous defeat. In French heur, malheur, heureux, malheureux, are all derived from the Latin augurium; the expression né sous une mauvaise étoile, born under an evil star, corresponds (with the change of étoile into astre) to the word malôtru, in Provençal malastrue; and son étoile pâlit, his star grows pale, belongs to the same class of illusions. The Latia ex augurio appears in the Italian sciagura, sciagurato, softened into sciaura, sciaurato, wretchedness, wretched. The influence of a particular planet has also left traces in various languages; but the French and English jovial and the English saturnine correspond rather to the gods who served as types in chiromancy than to the planets which bear the same names. In the case of the expressions bien or mal luné, well or ill mooned, avoir un quartier de lune dans la tetê, to have the quarter of the moon in one’s head, the German mondsüchtig and the English moonstruck or lunatic, the fundamental idea lies in the strange opinions formerly held about the moon.

Bibliography.—For the history of astrology with its affinities to astronomy on the one hand, and to other forms of popular belief on the other, the following works out of a large number that might be mentioned are specially recommended:—A. Bouché-Leclercq, L’Astrologie grecque (Paris, 1899), with a full bibliography; Franz Boll, Sphaera (Leipzig, 1903); Franz Cumont, Catalogus Codicum Astrologorum Graecorum (Brussels, 1898; 7 parts published up to 1909); Franz Boll, “Die Erforschung der antiken Astrologie” (in Neue Jahrbücher für das klassische Altertum, Band xxi. Heft 2, pp. 103-126); Franz Cumont, Les Religions orientales dans le paganisme romain (Paris, 1907) (ch. vii. “L’Astrologie et la magie”); Alfred Maury, La Magie et l’astrologie à l’antiquité et au moyen âge (4th ed., Paris, 1877); R. C. Thompson, Reports of the Magicians and Astrologers of Nineveh and Babylon (2 vols., London, 1900); F. X. Kugler, Sternkunde und Sterndienst in Babel (Freiburg, 1907;—to be completed in 4 vols.); Ch. Virolleaud, L’Astrologie chaldéenne (Paris, 1905—to be completed in 8 parts—transliteration and translations of cuneiform texts); Jastrow, Religion Babyloniens und Assyriens (Parts 13 and 14); also certain sections in Bouché-Leclercq, Histoire de la divination dans l’antiquité (Paris, 1879), vol. i. pp. 205-257; in Marcellin Berthelot, Les Origines de l’alchimie (Paris, 1885), pp. 1-56; Ferd. Höfer, Histoire de l’astronomie (Paris, 1846), pp. 1-90; in Rudolf Wolf, Geschichte der Astronomie (Munich, 1877), ch. i. See also the article by Ernst Riess on Astrology in Pauly-Wissowa, Realencyclopädie der klassischen Altertumswissenschaft, vol. ii. (Stuttgart, 1896). For modern and practical astrology the following works may be found useful in different ways: E. M. Bennett, Astrology (New York, 1894); J. M. Pfaff, Astrologie (Bamberg, 1816); G. Wilde, Chaldaean Astrology up to date (1901); R. Garnett (“A. G. Trent”), “The Soul and the Stars,” in the University Magazine, 1880 (reprinted in Dobson and Wilde, Natal Astrology, 1893); Abel Haatan, Traité d’astrologie judiciaire (Paris, 1825); Fomalhaut, Manuel d’astrologie sphérique el judiciaire (Paris, 1897).  (M. Ja.) 


ASTRONOMY (from Gr. ἄστρον, a star, and νέμειν, to classify or arrange). The subject matter of astronomical science, considered in its widest range, comprehends all the matter of the universe which lies outside the limit of the earth’s atmosphere. The seeming anomaly of classifying as a single branch of science all that we know in a field so wide, while subdividing our knowledge of things on our own planet into an indefinite number of separate sciences, finds its explanation in the impossibility of subjecting the matter of the heavens to that experimental scrutiny which yields such rich results when applied to matter which we can handle at will. Astronomy is of necessity a science of observation in the pursuit of which experiment can directly play no part. It is the most ancient of the sciences because, before the era of experiment, it was the branch of knowledge which could be most easily systematized, while the relations of its phenomena to day and night, times and seasons, made some knowledge of the subject a necessity of social life. In recent times it is among the more progressive of the sciences, because the new and improved methods of research now at command have found in its cultivation a field of practically unlimited extent, in which the lines of research may ultimately lead to a comprehension of the universe impossible of attainment before our time.

The field we have defined is divisible into at least two parts, that of Astronomy proper, or “Astrometry,” which treats of the motions, mutual relations and dimensions of the heavenly bodies; and that of Astrophysics (q.v.), which treats of their physical constitution. While it is true that the instruments and methods of research in these two branches are quite different in their details, there is so much in common in the fundamental principles which underlie their application, that it is unprofitable to consider them as completely distinct sciences.

Speaking in the most comprehensive way, and making an exception of the ethereal medium (see Aether), which, being capable of experimental study, is not included in the subject of astronomy, we may say that the great masses of matter which make up the universe are of two kinds:—(1) incandescent bodies, made visible to us by their own light; (2) dark bodies, revolving round them or round each other. These dark bodies are known to us in two ways: (a) by becoming visible through reflecting the light from incandescent bodies in their neighbourhood, (b) by their attraction upon such bodies.

The incandescent bodies are of two classes: stars and nebulae. Among the stars our sun is to be included, as it has no properties which distinguish it from the great mass of stars except our proximity to it. The stars are supposed to be generally spherical, like the sun, in form, and to have fairly well-defined boundaries; while the nebulae are generally irregular in outline and have no well-defined limits. It is, however, probable that the one class runs into the other by imperceptible gradations. In the relation of the universe to us there is yet another separation of its bodies into two classes, one comprising the solar system, the other the remainder of the universe. The former consists of the sun and the bodies which move round it. Considered as a part of the universe, our solar system is insignificant in extent, though, for obvious reasons, great in practical importance to us, and in the facility with which we may gain knowledge relating to it.

Referring to special articles, Solar System, Star, Sun, Moon, &c. for a description of the various parts of the universe, we confine ourselves, at present, to setting forth a few of the most general modern conceptions of the universe. As to extent, it may be said, in a general way, that while no definite limits can be set to the possible extent of the universe, or the distance of its farthest bodies, it seems probable, for reasons which will be given under Star, that the system to which the stars that we see belong, is of finite extent.

As the incandescent bodies of the universe are visible by their own light, the problem of ascertaining their existence and position is mainly one of seeing, and our facilities for attacking it have constantly increased with the improvement of our optical appliances. But such is not the case with the dark bodies. Such a body can be made known to us only when in the neighbourhood of an incandescent body; and even then, unless its mass or its dimensions are considerable, it will evade all the scrutiny of our science. The question of the possible number and magnitude of such bodies is therefore one that does not admit of accurate investigation. We can do no more than