Mr. J. Utting on a Planetary Analogy. 

 Satellite of the Earth. 



121 



Note. — The periodic times of the planets and satellites were taken from 

 the fourth edition of Laplace's Sydeme du Monde, the time being converted 

 from solar to sidereal days in the proportion of 1-0027378 to 1. The mass 

 or altraciive power of the sun, and planets, was also taken from the same 

 work, from which with the })eriodic time, and constant product, the distances 

 of all the satellites from their primaries were computed. The distance of 

 the ring of Saturn, is the distance from the centre of the planet to the 

 centre of attraction in the cylinder of the ring, or the centre of gravity of a 

 satellite, supposing all the particles of matter in the ring to be condensed 

 into a globular form, and whose sidereal period is equal to that of the ro- 

 tation of the ring. 



XXV. Stale of the Tliermometer at Smyrna for every Day in 

 the Year 1820 {bein^ the Year of the great Eclipse, and Leap- 

 year,) taken in the Shade four times every Day; viz. A.M., 

 Noon, 6 P.M., Midnight. Communicated from Smyrna by 

 a Correspondent to Dr. T. FonsTER. 



Vol. fj2. No. 301. Aug. 1823. 



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JANU- 



