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6. - the Length of the Day in Latitudes under 66J
Degrees ...................... . ............. ibid.
8. •• the Latitude where the longest day may be of
any given lenglh between twelve and twenty-four
15. - at what Hour a given Star transits the Meri.
dian ................ ibid.
17. To represent the Face of the Heavens for any given day
and hour . — .... ...... . ................... ibid.
28. - the Hour, the Latitude and Azimuth given .... 351
29. - -a Star, the Latitude, Sun's Place, Hour, &c.
given ........ . ......... . .............. ... ibid.
43. - the Moon's greatest and least Meridian Alti-
tude ...... . ................... . ....... .... ibid.
Tables of the New Planets, by the same 518
List of W. and S. Jones' Prices • 518
E«O O A
Mankind have in all ages been desirous of forming rational conceptions of the nature and motion of those bodies that appear in the vast concave above their heads. Amidst the infinite variety of objects which surround them on every side, the heavenly bodies must have been amongst those which first attracted their attention. They are of all objects the most conspicuous, the most important, and the most beautiful.
Astronomy instructs us in the laws, or rules, that govern and direct the motions of the heavenly host. It weighs and considers the powers by which they circulate in their orbs. It enables us to discover their size, determine their distance, explain their various phenomena, and correct the fallacies of the senses by the light of truth.
~ Astronomy is not merely a speculative science; its use is as extensive as its researches are sublime. Navigation owns it for its guide; by it, commerce has been extended and geography improved. It is astronomical observations that form the basis of geography. Thus, it has co-operated with other causes* in the greatest of all works, the diffusion of knowledge and the civilization of man.
As, in order to attain an accurate idea of any piece of mechanism, it is best to begin our investigation by an examination of those parts which give motion to the rest, the primary causes of those effects for which the machine was made; so the young pupils will more easily gain a just idea of the motion of the heavenly bodies, by considering them as seen from the; sun, the centre of our system, and the, principal agent used by the Lord Of Nature for conducting and regulating the planetary system.
It will not be difficult, after this, to inform hifli how those appearances are to be accounted for, that arise from his particular situation; whence he views the heavens from a point which is not in the centre of the system, and is consequently the source of many apparent irregularities. This knowledge at., tained, it will be easy to prove to him, that the real and apparent motions of the heavenly bodies are frequently the reverse of each other. For, being by this means put into possession of the universak of this science, the knowledge of particulars will be tendered facile and clear