THE 



PHILOSOPHICAL MAGAZINE. 



I. A Sympsis of the principal Elements of Astronomy; de- 

 diiced from M. Laplace's Exposition du Systeme du 

 Monde. CommzinicaLtd by Fkancis Baily, Esq. 



The following paper possesses no further merit than 

 as being a faithful abstract of the principles and facts given 

 by M. Laplace in his Exposition du Systeme du Monde, 

 It is taken from the /Ai/rf edition of that work (1608), 

 wherein the author has given the elements of the planets iu 

 a more correct manner than in either of the preceding edi- 

 tions; and wherein he has revised and amended all his for- 

 mer calculations by more recent and exact observations. 



The arrangeiDcnt of the prcbent memoir is somewhat 

 new : but many persons have frequently found the want of 

 a manual of this kind, where all the different ^ac/f, relative 

 to astronomy, might be brought under their respective 

 heads, without the necessity of turning to a variety of 

 works for inforniition. Much time is often lost in a re- 

 search of that kind, which it is the object of the present 

 abstract to prevent. 



In the original v/ork, the author has universally adopted 

 the decimal division of the day, and of the quadrant. This 

 method is here preserved in the Tables of the Elements of 

 the Planets (page 6) : but, in the subsequent pans, the 

 common sexagesmuL notation is adopted, as being more 

 easily understood in this country. 



Some other facts, not mentioned by M. Laplace, are in- 

 serted in this tract, in order to enlarge the view of the sub- 

 ject : but these passages arc always kept separate, by being 

 inclosed within brackets. 

 Vol. 39. No. IC5. Jan. 1812. A 2 Tlie 



