170 071 the Solar and Lunar Periods. 



M. BiOT. Astronomy (Physical and Elementary), 2d Edit. 

 3 vols. Oct. 1811. 



Days. 

 Tropical year . . . . . . 365 



Sidereal do. . . . . . . 365 



Sidereal rev. ]) . . . . . . 27 



Anomalistic do. . . . . . . 27 



Synodic do. .. .. .. 29 



Tropical rev. ]) 's perigee .. 3231 

 Sidereal do 3232 



o 



Sec. mot. of equinoctial points . . 1 



BuRCKHARDT. Lunar Tables, Quarto. 



s. 



Sec. mot. in long, in 100 Julian years 10 

 Do. of the ]) 's anomaly . . 6 



Do. ofthe D*s S .. .. 4 



Mr. Vince in the 2d edit, of his Complete System of Astro- 

 nomy, 3 vols, quarto. 1814, has adopted the solar and lunar 

 motions as given by M. de la Lande, in the 3d edition of his 

 Astronomy, as before stated, which have also been copied into 

 several of our modern astronomical works and Encyclopaedias. 

 In Taylor's Sexagesimal Tables, and in Button's Math, and 

 Phil. Dictionary, the tropical year is stated at 365 days 5 hours 

 48 min. 45 sec. Bonnycastle's Astronomy states it at half a se- 

 cond more. Barlow (Phil. Dictionary); Edinburgh and Imperial 

 Encyclopaedias; Lalande (Jstronomie); Laplace {Systeme du 

 Monde, 1st edit.); Squire (Grammar of Astronomy); Vince 

 (Astronomy); Woodhouse (Astro.); Whiting (Astronomy now 

 publishing) ; and Dr. Young in his Treatise on Philosophy, in 

 2 vols, quarto, state the mean length of the solar year at 365 

 days 5 hours 48 min. 48 sec. Dr. O. G. Gregory (Astro.) states 

 it at one second more. Mr. Burckhardt, 365 days 5 hours 48 

 min. 49-732 seconds. Laplace [Systeme du Monde, 4th edit.) ; 

 Delambre (Solar Tables) ; Biot (Astronomy) state the solar year 



* From which I have deduced the following periods : 



Days. hrs. min. sec. 

 Trop. rev. of the ]) . . . . 27 7 43 4-7053!) 



Sid. do. 



Anomalistic do. 

 Synodic do. 

 Rev. of the D to her gj 

 Trop. rev. of the > 's perigee 

 Sidereal do. 



Trop. rev. of the D 's gj 

 yidereal do. . . 



27 7 43 11-53824 



27 13 18 33-35681 



29 12 44 2-84517 



27 5 5 35-71380 



3231 10 56 57-02423 



3232 13 30 33-93601 

 6798 6 21 26-4000 

 G793 8 55 46-78841 



Sec. mot. equinoctial points being taken at 1 23 35 



at 



