-Comets of Halley, Encke, and Biela-Undu- latory Theory of Light-Dimensions of the XII. Fixed Stars-General Particulars--Positions of Heavenly Bodies-How to describe or find them-Classifications and Distinctions of Stars -Their Parallax-Lunar Distances, and the Longitude The Galaxy, or Milky Way- Double and Triple Stars, &c.-Nebula-Stars considered to be Suns-Pole-Star-Constella- XV. Astronomical Instruments, commonly used in the Measurement of Time-Early Divisions of Time-Sun-Dial, Horizontal and Vertical- RECREATIONS IN ASTRONOMY. INTRODUCTION. "WHEN I consider thy heavens, the work of thy fingers; the moon and the stars, which thou hast ordained;-what is man, that thou art mindful of him? and the son of man, that thou visitest him?" -Psalm viii., 3, 4. When the inspired Psalmist gave utterance to these words, he was evidently under the influence of those feelings of awe, wonder, and admiration, which are sure to be excited in every intelligent mind, by the splendid and sublime phenomena presented to us by the heavenly bodies. When we consider the magnitude and the number of those bodies, the immense distances which separate them one from another, the almost inconceivable velocity with which they move, and that those which we can see form, probably, but a very small part of the whole number;-when we revolve these things in our minds, we are naturally brought to reflect on our own insignificance in the grand scheme of creation. If a man, after having applied to himself the vain and self-satisfying appellation of "lord of the creation," were to remember that the glorious sun, and the planets which revolve around it, form but one particular division, class, or system in the B universe,—that the earth is but an humble member of that system, and that he, man himself, is but a moving particle on the surface of the earth, he may well be expected to give utterance to the sentiments of David, and to wonder how the Great Deity can regard with parental care so humble a member of so magnificent a whole. :-we But this feeling, as Addison has beautifully shown, arises from the narrow powers of our own minds. We know that our perceptive faculties soon reach a boundary beyond which we cannot pass: we study the laws of Optics, but we know not the nature of Light:feel that we live and think, but we know not what constitutes life and thought. When, therefore, we judge of the Great Creator, by our own standard, we are lost in wonder at the vastness and at the minuteness, as also at the countless number of the objects which are under the Divine protection. But when we consider God as an Omnipresent and Omniscient Being, we then admit, indeed, that nothing is too vast, nothing too minute, nothing too numerous, for His notice; that He who could create and arrange the whole, can also watch over and preserve the minutest parts of that whole. Our notions of great and small are derived from our own imperfect experience, and strikingly show the limited scope of our minds. The distance of the sun from the earth is a quantity so immense, as almost to perplex the mind which reflects on it; and yet that distance is small, compared with the distance of the fixed stars:-again, the minuteness of the nerves and smaller blood-vessels of the human body, is such as to require the microscope to aid us in an examination of their structure, and yet there are other entire animals, endowed with life and powers of motion, which are so minute that the eye cannot perceive them. The words great and small, then, are for man's use; to the Almighty nothing is great, nothing is small; the revolving planet, and the animalcule whose world is a drop of water, being equally objects of His ever-active care. This divinely-sustaining power of Him, in whom " we live, and move, and have our being," is so obvious, that we may exclaim with the poet Thomson Were every falt'ring tongue of man, Thy Works themselves would raise a general voice, By human foot untrod;-proclaim Thy power, Th' eternal cause, support, and end, of all! Nothing is more calculated to elevate the mind, and to display to us the wonders of Creation, than the study of Astronomy. We propose, therefore, to place before our readers a popular view of the elements, which serve for the basis of the astronomer's study. In doing this, we need not have recourse to the mathematical reasonings on which the various statements of the astronomer are founded; but we shall confine ourselves to such a simple explanation of the Mechanism of the Heavens as may pave the way for the study of a more systematic treatise. We trust, therefore, that both those who have, and those who have not, an opportunity of referring to more elaborate works, will not find the following pages devoid of instruction. |